WO1986002478A1 - Support d'enregistrement magnetique avec lubrifiant - Google Patents

Support d'enregistrement magnetique avec lubrifiant Download PDF

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Publication number
WO1986002478A1
WO1986002478A1 PCT/US1985/001981 US8501981W WO8602478A1 WO 1986002478 A1 WO1986002478 A1 WO 1986002478A1 US 8501981 W US8501981 W US 8501981W WO 8602478 A1 WO8602478 A1 WO 8602478A1
Authority
WO
WIPO (PCT)
Prior art keywords
recited
oil
combination
fluoro
lubricant
Prior art date
Application number
PCT/US1985/001981
Other languages
English (en)
Inventor
Fred Chi-Tat Chung
Ross Parker Clark
Original Assignee
Memorex Corporation
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from US06/661,983 external-priority patent/US4659627A/en
Application filed by Memorex Corporation filed Critical Memorex Corporation
Publication of WO1986002478A1 publication Critical patent/WO1986002478A1/fr

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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
    • G11B5/71—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 lubricant

Definitions

  • Such lubricated coatings are particularly important for magnetic tape (or like flexible disks) of the type used in computer recording, or in conjunction with video or audio recording where the relative head-medium velocity is very high, producing aggravated abrasion and reduced life (durability) of both head and media.
  • workers have resorted to various lubricant means for such tape coatings and like media (e.g., see the following U.S. Patents: 3,490,946, 3,492,235, 3,523,086, 4,431,702, 3,983,302, 3,837,912, and 3,597,273).
  • fluorosilicone/FAE-lube coatings of the invention are characterized by a fluorosilicone oil component in combination with a compatible stearate or like fatty acid ester component.
  • NML non-migrating lubricant
  • “harsh”) magnetic powder used here to yield high output signal performance at high recording densities (e.g., 10-30K FTPI).
  • DuPont's magnetic chromium . dioxide powder is a suitable CrO 2 . This formulation is optimized for an oxide loading level of about 79% by weight.
  • Soya Lecithin A liquid soya lecithin is preferred (e.g., 3FUB by Central Soya or GAFAC
  • Chromium dioxide in itself, is more conductive than conventional gamma ferric oxides and cobalt modified iron oxides. To give a more representative finished tape resistivity (0-1000 M ⁇ square), a minimum of 0.5% conductive carbon should be incorporated. This should also stabilize resistance, resulting in a manufacturable uniform product.
  • Tape conductivity must be regulated to avoid build-up of static charge which can interfere with proper transport of the tape and cause loose debris to collect on the tape, leading to loss of data ("dropouts”) and general untidiness,
  • Estane 5701F1 is a representative (polyesterurethane) binder polymer; with phenoxy, here it forms the binder bulk.
  • An Estane 5701F1 is a preferred polyesterurethane because of its high abrasion resistance and selected solvent compatibility.
  • another polyurethane ester may be substituted that yields a compatible mixture and is solvent-system-compatible; and that will cause the FS oil to migrate.
  • Other binder materials useful with such CrO 2 (computer tape) formulations will be evident; [polyurethane and vinyl types are preferred].
  • Phenoxy PKHJ/PKHH — are representative (phenoxy polymer) binder coconstituents with the polyester urethane (Estane 5701F1) and cross-linker (below).
  • a polyisocyanate polymer is a good binder/cross-linker for the phenoxy-in-polyurethane, and a curing agent; i.e., the isocyanates to react with the hydroxyl groups in the phenoxy polymer (the Estane is pre-cured) to form a thermosetting system which provides exceptional flexibility and adhesion/cohesion under extreme environmental conditions.
  • a curing agent i.e., the isocyanates to react with the hydroxyl groups in the phenoxy polymer (the Estane is pre-cured) to form a thermosetting system which provides exceptional flexibility and adhesion/cohesion under extreme environmental conditions.
  • Other like cross-linkers will be evident to workers [e.g., Mondur CB-75 by Mobay; Spenkel P-49-60CX by Spencer Kellog; PAPPI by Upjohn; Adiprene series by Dupont].
  • an FAE concentration of 1-7 wt.% of solids is preferred to give desirable surface quality (cf. when combined with FS oil, a very desirable durability and abrasion performance is realized).
  • Fluorosilicone Oil FS-1265 or a like liquid (FS-1265 by Dow fluorosilicone (FS oil) is Corning, pref.) — found to combine surprisingly well with FAE for CrO 2 coatings. It has a migrating effect, providing constant lubrication specifically to minimize friction on the tape surface, yielding very low abrasion there (headtape contact) and excellent durability (wear resistance).
  • FS-1265 is an oil that was heretofore specified merely for gross lubrication uses (e.g., as a base for pump grease or bearing lube oils, etc.) It was also thought feasible to help smooth a coating's finish; but it was quite unexpected to find that it could be used to ameliorate the durability and abrasivity problems of such a CrO 2 computer tape composition — without adverse side effects, and especially in such concentrations. This will not only surprise workers but will prove very practical, because, such FS oil is widely available and low in cost (e.g., less expensive than pure fluorocarbon).
  • FS-1265 e.g., about 0.1-.2 wt.% solids
  • very fine durability e.g., 100K+ cycles — stearate at 1.0% here
  • was somewhat too abrasive abras. index of 123-144
  • doubling the stearate and FS-1265 concentrations e.g., to about 2 wt.% and .3 - .4 wt.% resp. kept this excellent durability
  • composition of Ex. I is prepared by procedures well known in the art.
  • the formulation premix is milled and dispersed in enough solvent to give a final solid composition with 30 to 40% non-volatiles. Milling is continued until a stable high quality dispersion is obtained.
  • the final formulation is applied as a thin (e.g., 0.0002") film on computer tape (cf. PET, polyethylene terephthalate web about 0.0014" thick).
  • the so-coated tape is subjected to particle orientation, curing, drying, and surface-treatment as known in the art.
  • a 1.35 mil basefilm is preferred for a high performance tape product; however, a .92 mil or thinner basefilm can also be used. Basefilm requirements will depend upon final product packaging and length/data storage requirements.
  • a "clog index" is: no. of clog events x 10 passes x 8 tracks x 10 actual passes act. tracks
  • Formulations with such oxide loading levels (76-79 wt.% or higher; cf. the pigment-to-binder ratio in the final tape formulation of 4.82/1 is considered extremely high for magnetic tape, vs a "normal” 3.63/1) can achieve high outputs at 25K ftpi (more than 180%). Durability is excellent for such high oxide loading levels, as was "wiper debris". Considering the overall performance, such a CrO 2 formulation will be preferred by artisans for high performance computer tape.
  • the only lube constituent is a silicone oil, durability will be very poor (e.g., Molykote 4-3600 silicone oil by Dow Corning will give about 10K or less).
  • the only lube constituent is a fluorosilicone oil (FS-1265 or the like; no fatty acid ester), one will realize a very low durability (about 1K cycles) and poor abrasion values.
  • a FS/FAE lube according to the invention can increase durability enormously, ii.
  • Abrasivity tests (either the "Fullmer” abrasivity method or the Memorex in-house-developed “Radicon” test) denote head wear as a function of the abrasivity of the magnetic computer tape.
  • chromium dioxide is used with the state-of-the-art lubrication system, abrasivity increases markedly.
  • the FS-FAE lube system of the invention can meet this problem also, reducing abrasivity.
  • the FS/FAE lube also alleviates "clog” and reduces "wear debris".

Landscapes

  • Paints Or Removers (AREA)

Abstract

Supports d'enregistrement magnétique revêtus d'un pigment dur tel que des particles de CrO2 et permettant de fréquents contacts avec une tête de lecture, et présentant de bonnes caractéristiques de durée, abrasivité, etc., et utilisant un système lubrifiant comprenant une huile aux fluoro-silicones et un ester d'acide gras compatible tel que le stéarate d'éthyle butoxy.
PCT/US1985/001981 1984-10-17 1985-10-15 Support d'enregistrement magnetique avec lubrifiant WO1986002478A1 (fr)

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
US661,983 1984-10-17
US06/661,983 US4659627A (en) 1984-10-17 1984-10-17 Magnetic recording medium with lubricant
US68172784A 1984-12-14 1984-12-14
US681,727 1984-12-14

Publications (1)

Publication Number Publication Date
WO1986002478A1 true WO1986002478A1 (fr) 1986-04-24

Family

ID=27098432

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/US1985/001981 WO1986002478A1 (fr) 1984-10-17 1985-10-15 Support d'enregistrement magnetique avec lubrifiant

Country Status (2)

Country Link
EP (1) EP0202250A1 (fr)
WO (1) WO1986002478A1 (fr)

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3211976A1 (de) * 1981-04-01 1982-10-21 TDK Electronics Co., Ltd., Tokyo Magnetischer aufzeichnungstraeger
DE3212030A1 (de) * 1981-04-01 1982-11-11 TDK Electronics Co., Ltd., Tokyo Magnetischer aufzeichnungstraeger
US4416948A (en) * 1981-04-01 1983-11-22 Tdk Electronics Co., Ltd. Magnetic recording medium
EP0116923A1 (fr) * 1983-02-12 1984-08-29 Hitachi Maxell Ltd. Milieu d'enregistrement magnétique

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3211976A1 (de) * 1981-04-01 1982-10-21 TDK Electronics Co., Ltd., Tokyo Magnetischer aufzeichnungstraeger
DE3212030A1 (de) * 1981-04-01 1982-11-11 TDK Electronics Co., Ltd., Tokyo Magnetischer aufzeichnungstraeger
US4416948A (en) * 1981-04-01 1983-11-22 Tdk Electronics Co., Ltd. Magnetic recording medium
EP0116923A1 (fr) * 1983-02-12 1984-08-29 Hitachi Maxell Ltd. Milieu d'enregistrement magnétique

Also Published As

Publication number Publication date
EP0202250A1 (fr) 1986-11-26

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