Abstract: Described is a technique and associated fixture for lapping magnetic recording heads in a group such that each head is mounted on a "free floating" part in the fixture, being biased for lapping only by the weight of this part and being individually removable during lapping mode; and also characterized by capability for pivoting the fixture to change the lap-angle of all such heads in common to a new constant prescribed angle, the parts also being selectibly kept non-rotatable in the fixture.

Abstract: Described is a novel "bevel tool" and associated technique for holding prescribed magnetic head workpieces and placing them in prescribed constant angular relation with a rotary lapping means; this tool preferably including a workpiece-receiving pocket adapted to be spread apart and to resiliently grip the work, with one or more guide-faces surrounding this pocket and adapted to indicate a prescribed orientation of the work against a prescribed "lapping plane".

Abstract: A method and associated fixture for magnetically attracting and holding back-bar to respective magnetic core-leg portions of a typical magnetic slider assembly. A plurality of embodiments constructed in accordance with different fabrication techniques are described.

Abstract: Described is a fixture for glass-bonding a digital magnetic recording slider workpiece (the component parts thereof), while holding them carefully aligned. In one preferred embodiment this fixture includes a slot for receiving a number of such work pieces in pre-assembled form registering and aligning them together and providing retainer means individually for each work piece adapted to resiliently and selectively engage each work piece and hold it positively in careful precise alignment while glass bonding and related operations carried out on the array of multiple work pieces so-aligned and retained.

Abstract: Described is a fixture for glass-bonding a digital magnetic recording slider workpiece (the component parts thereof), while holding them carefully aligned. In one preferred embodiment this fixture includes a slot for receiving a number of such work pieces in pre-assembled form registering and aligning them together and providing retainer means individually for each work piece adapted to resiliently and selectively engage each work piece and hold it positively in careful, precise alignment while glass-bonding and related operations carried out on the array of multiple work pieces so-aligned and retained.

Abstract: Described is a novel method and associated fixture for magnetically attracting and holding back-bar means to respective magnetic core-leg portions of a typical magnetic slider assembly.

Abstract: The invention relates to a process for coloring water-insoluble thermoplastic plastics with dyestuffs of the formula ##STR1## The dyestuffs are added to the melt of the thermoplastic plastic or to its precursors.

Abstract: 2,5-Bis-(4'-aminophenyl)-1,3,4-oxadiazoles which are chlorinated in the phenyl nuclei are obtained by condensing hydrazine or a hydrazine yielding agent with equal or different chlorinated benzoic acids or acylating acid derivatives having in para-position to the acid group an amino group or a group capable of being transformed into the amino group, and, thereafter, effecting ring closure of the so-obtained bis-hydrazide to yield the oxadiazole. The products are bis-diazo components, especially for pigments having a very high tinctorial strength, clear and pure shades, a good fastness to light, to heat and to solvents.

Abstract: Compositions of linear trans-quinacridones containing at least one component (I) selected from unsubstituted, chloro- and methyl-substituted quinacridone and at least one component (II) selected from bis-(carbamoyl)-quinacridones, the carbamoyl groups of which are unsubstituted, N-mono-alkyl substituted or N,N-dialkyl-substituted, are pigments useful for coloring plastics and especially lacquers. These compositions are preferably prepared by joint ring closure of the corresponding 2,5-dianilino-terephthalic acids or esters.

Abstract: Monoazo compounds of the formula ##STR1## wherein A stands for --NH--CO--NH--, --NH--CO--CO--NH-- or --NH--CO--NH--CO--,B stands for --CO-- or --CO--CO--,R.sup.1, R.sup.2 and R.sup.3 each stands for hydrogen, chlorine, methyl, methoxy, ethoxy, nitro or a group of the formula --COOR with R being hydrogen, methyl or ethyl andR.sup.4 stands for hydrogen, chlorine, methyl, methoxy or ethoxy,with the proviso that when B stands for --CO-- and when(1) A stands for --NH--CO--NH--(a) either R.sup.4 is different from hydrogen, or(b) at least one of the radicals R.sup.1, R.sup.2 and R.sup.3 stands for nitro or COOR, or(c) at least two of the radicals R.sup.1, R.sup.2 and R.sup.3 are different from hydrogen,and when(2) A stands for --NH--CO--CO--NH-- or --NH--CO--NH--CO'(a) R.sup.4 is not in the 6-position or(b) at least one of the radicals R.sup.1, R.sup.2 and R.sup.

Abstract: Monoazo compounds of the general formula ##STR1## in which R is hydrogen, methyl or ethyl. The monoazo compounds are valuable pigments which are especially useful for coloring baking varnishes and plastics. They also exhibit characteristics of good fastness to light, weathering, migration, especially overvarnishing and heat stability.

Abstract: The catalytic hydrogenation of o-nitro-chlorobenzene in aqueous alkali metal hydroxide solution with addition of an aromatic non-watermiscible solvent at an elevated temperature and under pressure using a noble metal catalyst and a polycyclic quinone as a co-catalyst leads to high and well-reproducible yields of 2,2'-dichloro-hydrazobenzene when the quinone is a derivative of anthraquinone, especially a hydroxy-anthraquinone. The product is obtained in so high a quality that it can be transformed without isolation or purification into 3,3'-dichlorobenzidine.

Abstract: Easily dispersible preparations of organic pigments are obtained by coating the pigment particles with essentially colorless aromatic compounds having a molecular structure being similar to that of the pigment and having an aliphatic chain of more than 5 carbon atoms. These preparations are stable to flocculation and useful for pigmenting hydrophilic and hydrophobic media.

Abstract: Unsubstituted linear trans-quinacridone of the gamma-crystal modification is obtained by cyclization of 2,5-dianilino-terephthalic acid with the 2.5 to 4-fold quantity of polyphosphoric acid or of an acidic polyphosphoric acid methyl ester, followed by hydrolysis of the condensation product in water, intensive grinding of the aqueous crude quinacridone in the presence of an alcohol or ketone and heating of the resulting product to 80.degree. to 200.degree. C.

Abstract: 2,5-Diarylamino terephthalates are obtained in good yields and excellent purity when the aromatic nitro compound used for oxidizing the corresponding dihydro-2,5-diarylamino terephthalate contains the aromatic radical of said diarylamino groups, i.e. when the amine formed during the oxidation is that from which said diarylamino groups device. The products yield very pure quinacridone pigments and allow the synthesis of only one isomer of substituted quinacridones.

Abstract: Naphthalimide-4,5-dicarboxylic acids of the formula ##STR1## or the anhydrides thereof, wherein R is alkyl having 1 to 8 carbon atoms or hydroxyalkyl or alkoxyalkyl having each 1 to 6 carbon atoms in the alkyl or alkoxy portion, which are obtained by reacting an alkali metal salt of naphthalene-1,4,5,8-tetracarboxylic acid in an aqueous solution with amines of the formulaH.sub.2 N -- R (II)wherein R has the above meaning, at a pH-value of 5.2 to 7.5 and at temperatures of 80.degree. to 160.degree. C, are intermediates for disperse dyestuffs.

Abstract: Treating compounds of the formula ##STR1## in which the nuclei marked "A" and "B" can be substituted by halogen, lower alkyl, lower alkoxy or phenyl, with acid binding agents at elevated temperatures in polar organic solvents yields compounds of the formula ##STR2## in which A and B have the same meaning. The products are dyestuffs of high brillancy, pure shades, high fluorescence, excellent tinctorial strength and good fastness to light.

Abstract: Novel naphthalimide-4,5-dicarboxylic acids of the general formula ##STR1## or the anhydrides thereof, wherein R.sub.1 is hydrogen, hydroxy, amino, alkyl having 1 to 8 carbon atoms, hydroxyalkyl, alkoxyalkyl, aminoalkyl, monoalkylaminoalkyl, hydroxyalkoxyalkyl, alkoxyalkoxyalkyl, carbalkoxyalkyl, carboxyalkyl or phenylalkyl having each 1 to 6, preferably 1 to 4 carbon atoms in the alkyl or alkoxy portion or phenyl substituted by 1 to 3 halogen atoms, amino, alkyl, alkoxy, acylamino, acyl having each 1 to 4 carbon atoms, benzoyl or Carboxyl, and a process for preparing them, wherein naphthalene-1,4,5,8-tetracarboxylic acid, the mono- or dianhydride thereof are reacted as alkali salts in an aqueous solution with amines of the formulaH.sub.2 N - R.sub.1 (II)wherein R.sub.1 has the above meaning, at a pH-value of 5.2 - 7.5, preferably of 5.4 - 6.4, at temperatures of 80 to 160.degree. C.

Abstract: Benzoxanthene- and benzothioxanthene-dicarboxylic acid imide dyestuffs of the general formula ##SPC1##WhereinX is oxygen or sulfur,R is amino which is substituted by one or two members of the group of alkyl, cyclohexyl, benzyl, acyl, phenyl, .beta.-cyanoethyl, .beta.-hydroxyethyl, sulfamidophenyl, benzoyl, dichlorobenzoyl, sulfamidobenzoyl, carboxamidophenyl, phenylsulfonyl sulfamidodichlorobenzoyl, chlorophenyl, phenoxyacetyl lower alkylsulfamidobenzoyl and benzimidazdyl,R.sub.1 and R.sub.2 are hydrogen chlorine, bromine, cyano, lower carbalkoxy, lower alkyl, lower alkoxy and phenyl,R.sub.3 and R.sub.4 are hydrogen, lower alkoxy and lower hydroxy alkoxy.

Abstract: Process for preparing naphthoylene-arylimidazo-peri-dicarboxylic acid-imide-compounds of the formula ##SPC1##Wherein R.sub.1 is hydrogen, hydroxy or amino, phenyl, alkyl having 1 to 8 carbon atoms, hydroxyalkyl, alkoxyalkyl, amino-alkyl, mono- or dialkylaminoalkyl, hydroxyalkoxyalkyl, alkoxyalkoxyalkyl, carbalkoxyalkyl, carboxylalkyl or phenyl-alkyl having each 1 to 6, preferably 1 to 4 carbon atoms in the alkyl or alkoxy portion and R is hydrogen or halogen, alkyl, alkoxy, carbalkoxy having each 1 to 4 carbon atoms, nitro, cyano, carbonamido, mono- or dialkylcarbonamido or sulfonamido, mono- or dialkylsulfonamido and n represents the integers 1 to 3, in which process naphthalimide-4,5-dicarboxylic acids of the general formula ##SPC2##Or the anhydride thereof are condensed in an aqueous medium with a diamine of the general formula ##SPC3##At temperatures of from 80.degree. to 160.degree.C. R.sub.1, R and n having the above meanings.