-
公开(公告)号：DE2556188A1
公开(公告)日：1977-06-23
申请号：DE2556188
申请日：1975-12-13
Applicant: BASF AG
-
公开(公告)号：DE2540874A1
公开(公告)日：1977-03-24
申请号：DE2540874
申请日：1975-09-13
Applicant: BASF AG
Inventor： OHLINGER MANFRED DIPL CHEM DR , GRAU WERNER DIPL CHEM DR , STRITZINGER HEINZ DIPL ING , SCHOENAFINGER EDUARD DIPL CHEM
Abstract: Prod. having high coercive force is produced by pptg. Co(OH)2 from a Co(II) salt soln. with ammonia onto goethite crystallised from an alkaline soln. The prod. is subjected to reduction into magnetite. Subsequently the magnetite is oxidised with O2 at 200-400 degrees C to produce cobalt doped gamma-Fe2O3. Process is improved by pretreating the surface of goethite (before the introduction of the Co(II) salt) with an acid having pK 4.8; adjusting pH to 3-7 and maintaining the surface acidity within this range to the end of the redn. process. gamma-Fe2O3 suitable for magnetic recording is produced. Its coercive force is increased (compared with the known material) by the increased quantity of the cobalt dopant. The above process permits an increase in the cobalt doping without impairing the thermal stability and the toughness of the product. The reduction stage can be carried out at temps. as low as 250-290 degrees C.
-
公开(公告)号：DE2364878A1
公开(公告)日：1975-07-03
申请号：DE2364878
申请日：1973-12-28
Applicant: BASF AG
Inventor： ROLLER HERMANN , STRITZINGER HEINZ DIPL ING , HARTMANN JOB-WERNER DIPL CHEM , SCHNEIDER WALTER
Abstract: A magnetic recording tape consists of a non-magnetic carrier film, a magnetic layer contg. a finely divided magnetic pigment in a binder, and on the back of the carrier a non-magnetic backing layer, with higher electrical conductivity than the carrier, consisting of a mixt. of (A) an organic polymeric binder and (B) a powder mixt. of (a) 15-60 (15-35) pts. wt. conducting carbon black particles, (bi) 5-40(25-35) pts. of a reaction rpod. of montmorillonite, Al2(OH)2 Si4O10 .H2O, with an alkylammonium base, or (b2) 15-85 pts. of a powdered mixt. of 15-90(24-31) wt. % flaky silicate particles with Mohs hardness >6(>5) and 85-10 wt. % cubic or spherical particles of hard, durable oxides of Al, Si and/or Cr, and (c) 20-55 pts. wt. of a finely divided inorganic non-magnetic filler. The backing layer resists rapid coiling of the tape, is not sensitive to dust, and has improved bonding and crack-resistance. (A) The binder is esp. an elastomeric polyurethane free from NCO, prepd. from a polyester of a 4-6C aliphatic dicarboxylic acid and 3-10C diol, and a 6-24C (8-20C) diisocyanate, with a glycol extender; the polyurethane may be mixed with is not >40 (10-30) wt. % of other binders, e.g. vinyl(idene) chloride polymers or an epoxy resin, esp. from bisphenol A and epichlorohydrin. Copolymers of 70-95(75-90) wt. % vinyl chloride and 50-5% of a 1-3C alkyl ester of a 3-5C unsatd. acid may also be used as binder, e.g. a copolymer of 70-90% vinyl chloride, 5-15% dimethyl maleate and 5-15% diethyl maleate.
-
公开(公告)号：DE2364877A1
公开(公告)日：1975-07-03
申请号：DE2364877
申请日：1973-12-28
Applicant: BASF AG
Inventor： GROSS EGON VON DIPL CHEM DR , STRITZINGER HEINZ DIPL ING , HARTMANN JOB-WERNER DIPL CHEM , STEUERWALD MANFRED , KLEIN URSULA , SCHAEFER DIETER DIPL CHEM DR
Abstract: Magnetic recording media comprising a non-magnetizable flexible base and a firmly adhering magnetic coating based on a dispersion, containing a silane, of a magnetic pigment in a polymeric binder, and a process for their manufacture. The silane is an aminoalkylsilane RnSi(OR')4-n, wherein n is 1, 2 or 3, R' is alkyl of 1 to 8 carbon atoms and R is aminoalkyl of the formula with one or more primary and/or secondary amino groups and from 3 to 11 carbon atoms. Magnetic recording media comprising a magnetic coating containing such a silane exhibit better abrasion resistance and better electromagnetic properties than comparable coatings.
-
公开(公告)号：DE2312848A1
公开(公告)日：1974-09-26
申请号：DE2312848
申请日：1973-03-15
Applicant: BASF AG
Inventor： STRITZINGER HEINZ DIPL ING , HARTMANN JOB-WERNER DIPL CHEM , BALZ WERNER DIPL CHEM DR , OSTERTAG WERNER DIPL CHEM DR
Abstract: Aluminium or Al alloy discs coated with a magnetic layer contg. 3-9, pref. 4-6 wt.% corundum powder, where pref. 40-60 wt.% of the corundum has a particle size of 110-200% of the thickness of the final ground magnetic layer, the remainder having a size =110% of this thickness. A corundum paste is prepd. by mixing sharp-edged corundum, size 1-10 mu with an epoxy resin having an epoxide equiv. wt. of 1000-2000 made from epichlorohydrin and 2,2-bis(4-hydroxyphenyl)-propane dissolved in toluene and ethylene glycolmonoethylether-monoacetate (I) to form a resin soln. (II). This paste is added to a mixt. of needle-shaped gamma Fe2O3 (average particle length 0.8 mu) with a further amt. of (I) and (II) plus a hardenable melamine-formaldehyde and sprayed on one or both sides of the Al disc (which may first be coated with a laquer) to form a film 3.9-4.4 mu thick. After curing, the surface is ground with rotating discs of porous polyvinyl alcohol sponge using diamond powder (7 mu) and a press. of 0.4 kg/cm2, followed by polishing with felt and diaminod powder (1) mu). The final magnetic layer is 3.8-4.1 mu thick.
-
Patent Agency Ranking
公开(公告)号：DE2714589A1
公开(公告)日：1978-10-12
申请号：DE2714589
申请日：1977-04-01
Applicant: BASF AG
Inventor： OHLINGER MANFRED DR , STRITZINGER HEINZ DIPL ING , VAETH GUENTER , WETTSTEIN EUGEN
Abstract: Magnetic recording material, e.g. tape, is made using a substrate for a consolidated layer of fine, acicular, magnetic iron oxide dispersed in a polymer binder dissolved in an organic solvent. Oxide is mixed with 5-100% of the binder for 2-24 hrs. in a rotating vessel of the usual type employed to mix solids; and mixing is at a temp. below the softening point of the binder. The mix obtd. is then processed with the remainder of the binder, the solvent, and further addns., in a known man manner to make a dispersion applied as a thin, uniform layer, with simultaneous magnetic alignment of oxide, onto the substrate; the solvent is then evaporated to consolidate layer. Used esp. in the mfr. of magnetic recording tape. An economic process of obtaining a high packing density of oxide without impairing the magnetic properties of that oxide.
-
公开(公告)号：DE2633999A1
公开(公告)日：1978-02-09
申请号：DE2633999
申请日：1976-07-29
Applicant: BASF AG
Inventor： SANNER WILLY DIPL ING DR , STRITZINGER HEINZ DIPL ING , DIEHL HEINZ , NICKLAS EGON , GAISER DIETER ING GRAD , BESMEHN LOTHAR
Abstract: Procedure for regulating tension of material in a winding equipment in which a band of material is run between a winding-off roller and a winding-on roller by means of tensioning roller arrangement. The run of the band material between the winding-off and winding-on rollers (8, 3) and the radius (R) of the winding (1) on the winding on roller (3) is continuously measured and the measured values multiplied. The product of the multiplication is fed in a regulator (14) which after comparing the obtained value with a predetermined value is influencing a braking force of a braking equipment (16) on the winding off roller (8). Thereby the torque of the winding (1) on the winding on roller (3) resulting from the product of both measured values is corresponding to the predetermined value.
-
公开(公告)号：DE2550307A1
公开(公告)日：1977-05-18
申请号：DE2550307
申请日：1975-11-08
Applicant: BASF AG
Inventor： OHLINGER MANFRED DIPL CHEM DR , SCHOENAFINGER EDUARD DIPL CHEM , SCHNEIDER WALTER , STRITZINGER HEINZ DIPL ING , VAETH GUENTER
Abstract: Acicular gamma-iron(III) oxide is manufactured by reacting an iron(II) salt solution with an aqueous solution of an alkali metal hydroxide and oxidizing the resulting suspension of iron(II) hydroxide in three stages. In a first stage, at most from 0.1 to 4% by weight of the amount of iron(II) hydroxide originally present is oxidized in the course of from 0.1 to 4 hours, in a second stage from 10 to 25% by weight of the said original amount are oxidized in the course of from 1.5 to 6 hours and in a third stage the remaining amount is oxidized. After the oxidation, the goethite formed is reduced to magnetite and the latter is then oxidized to acicular gamma-iron(III) oxide.
-
公开(公告)号：DE2461937A1
公开(公告)日：1976-07-08
申请号：DE2461937
申请日：1974-12-31
Applicant: BASF AG
Inventor： OHLINGER MANFRED DIPL CHEM DR , STRITZINGER HEINZ DIPL ING , HARTMANN JOB-WERNER DIPL CHEM , SCHOENAFINGER EDUARD DIPL CHEM
Abstract: In the prodn. of acicular alpha-Fe2O3 (I) by pptn. of hydrated alpha-Fe2O3 (II) from aq. Fe(II) salt solns. with alkali, with simultaneous oxidn. with air, and dehydration, polymers (III) contg. carboxyl gps. with an acid no. of over 50, pref. 80-220, are added during the prodn. of (I). (III) pref. is added to the (II) suspension in an amt. of 1.5-10, esp. 3-6 (wt.) pts/100 pts. (II). (III) can be (co)polymers of an alpha,beta-unsatd. carboxylic acid or reaction prods. of phthalic acid or anhydride with polyalcohols. (I) is used for the prodn. of acicular gamma-Fe2O3 (IV), which is used for low-noise magneto-gram carriers. The (I) obtd. gives esp. low-noise (IV) with good controllability and without additional process stages.
-
公开(公告)号：DE2550308A1
公开(公告)日：1977-05-18
申请号：DE2550308
申请日：1975-11-08
Applicant: BASF AG
Inventor： OHLINGER MANFRED DIPL CHEM DR , SCHOENAFINGER EDUARD DIPL CHEM , VAETH GUENTER , STRITZINGER HEINZ DIPL ING , KOESTER EBERHARD DIPL PHYS DR , SCHNEEHAGE HANS HENNING DIPL C , STECK WERNER DIPL CHEM DR
Abstract: Goethite is obtained by reacting an aqueous solution of an iron (II) salt with an aqueous solution of an alkali metal hydroxide and oxidizing the resulting iron(II) hydroxide. The oxidation is carried out in three stages. In the first stage, from 4 to 15% by weight are oxidized in the course of from 0.4 to 5 hours, in the second stage from 60 to 85% by weight are oxidized in the course of from 1.5 to 6 hours and in a third stage the remaining amount of iron is oxidized.
-
-
-
-
-
-
-
-
-
Search Results
16
records
(took 0.025 seconds)
