Classifications

• • G—PHYSICS
  • G11—INFORMATION STORAGE
  • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
  • G11B5/00—Recording by magnetisation or demagnetisation of a record carrier; Reproducing by magnetic means; Record carriers therefor
  • G11B5/62—Record carriers characterised by the selection of the material
  • G11B5/68—Record carriers characterised by the selection of the material comprising one or more layers of magnetisable material homogeneously mixed with a bonding agent
  • G11B5/70—Record carriers characterised by the selection of the material comprising one or more layers of magnetisable material homogeneously mixed with a bonding agent on a base layer
  • G11B5/7013—Record carriers characterised by the selection of the material comprising one or more layers of magnetisable material homogeneously mixed with a bonding agent on a base layer characterised by the dispersing agent
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L75/00—Compositions of polyureas or polyurethanes; Compositions of derivatives of such polymers
  • C08L75/04—Polyurethanes
  • C08L75/06—Polyurethanes from polyesters
• • G—PHYSICS
  • G11—INFORMATION STORAGE
  • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
  • G11B5/00—Recording by magnetisation or demagnetisation of a record carrier; Reproducing by magnetic means; Record carriers therefor
  • G11B5/62—Record carriers characterised by the selection of the material

Definitions

• This invention relates to magnetic recording tapes and, more particularly, relates to magnetic recording tapes wherein a novel fatty acid soap of a long chain diamine is used as a dispersing agent informing a dispersion of the magnetic iron oxide utilized in making the recording tape.
• the dispersant mixture contains at least 50% of the diamine soap in order to secure effective results.
• the novel dispersant was employed in conjunction with a polyurethane resin system.
• the particular polyurethane employed is sold under the trade name of Estane 5701 by B. F. Goodrich.
• This particular polyurethane was made by reacting p-p'- diphenylmethane diisocyanate, adipic acid and butanediol- 1,4 in such proportions that all of the isocyanate groups have reacted to give a substantially unreactive polymer having the following characteristics:
• This polyurethane resin can be used either alone or in combination with other resins such as a vinyl chloridevinyl acetate copolymer.
• the particular copolymer selected is one sold under the trade name VAGH by Union Carbide and Chemical Corporation.
• This particular vinyl chloride-vinyl acetate copolymer contains approximately: 91% vinyl chloride; 3% vinyl acetate; 6% vinyl alcohol.
• This copolymer has an intrinsic viscosity in cyclohexanone at 20 C. of 0.57 c.p.s. and a specific gravity of 1.39.
• a novel fatty acid soap of a long chain diamine is employed to replace all or part of the licithin which is normally used in pre paring dispersions of magnetic iron oxides.
• One particularly suitable fatty acid soap is sold under the trade name Troykyd 98C, and this is a soap made by reacting stoichiometric amounts of a saturated fatty acid having from 12 to 18 carbon atoms and a diamine having from 12 to 18 carbon atoms in each chain.
• Troykyd 98C has a molecular weight of about 490. As the following examples show, this can be effectively combined with lecithin for use as a dispersant or it can be used along as a dispersant.
• Components 1 to 5 are dispersed in a pebble-mill using appropriate amounts of methylethyl ketone, methylisobutyl ketone and toluol for 48 hours. At the end of this grinding period a solution of the binder in similar solvents is added and grinding is continued for 24 hours. This mixture is then coated on a plastic base and dried.
• Example 3 The dispersion and coating of this example is the same as Example 1.
• the improvement consisting essentially of employing as a dispersing agent a diamine soap having a molecular weight of about 490; said soap being made from a fatty acid having 12 to 18 carbon atoms and a diamine having from 12. to 18 carbon atoms in each chain.
• the dispersant comprises a mixture of the long chain fatty acid-diamine soap and lecithin, wherein the amine soap constitutes at least one half of the dispersant.

Priority Applications (6)

Applications Claiming Priority (1)

Publications (1)

Family

ID=23831478

Family Applications (1)

Country Status (5)

Families Citing this family (2)

Citations (2)

• 1965
  • 1965-06-03 US US461170A patent/US3412044A/en not_active Expired - Lifetime
• 1966
  • 1966-05-18 DE DEA52561A patent/DE1285004B/de active Pending
  • 1966-05-27 BE BE681701D patent/BE681701A/xx unknown
  • 1966-05-27 GB GB24004/66A patent/GB1079609A/en not_active Expired
  • 1966-06-02 NL NL6607670A patent/NL6607670A/xx unknown

Patent Citations (2)

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