Abstract: The invention relates to imidazolidinone derivatives formed from the reaction of (1) a substituted-ethyl imidazolidinone; (2) substituted ethyl/propyl propylene urea or (3) a cyclic propylene urea with: (a) a C.sub.1 -C.sub.24 alkyl or a C.sub.3 -C.sub.24 alkenyl substituted anhydride or, (b) a C.sub.3 -C.sub.24 carboxylic acid or corresponding ester; their compositions and use as corrosion inhibitors and/or surfactants.

Abstract: Enamel frit powder for electrostatic application with a surface resistance greater than 10.sup.16 ohms containing alkaline oxides and alkaline oxides wherein the weight ratio of the alkaline oxides Na.sub.2 O:K.sub.2 O and the weight ratio of the alkaline earth oxides CaO:BaO is each about 1:1, containing______________________________________ % by weight ______________________________________ SiO.sub.2 36-40 Al.sub.2 O.sub.3 0-4 B.sub.2 O.sub.3 12-16 Na.sub.2 O 7-9 K.sub.2 O 7-9 ZrO.sub.2 5-10 CaO 4-6 BaO 4-6 P.sub.2 O.sub.5 0-1 CoO 1 NiO 2 MnO 0-2 CuO 0-2 F 0.1.

Abstract: An enamel frit for producing an acid-resistant enamelled steel in a single coating comprising at least about 40% of silicon atoms, 50% of silicon atoms and boron atoms, where the proportion of the boron atoms should not fall below 6.5%, 63% of silicon atoms, boron atoms and sodium atoms, where the proportion of the sodium atoms should not fall below 7.5%, each relative to the overall total of the non-oxygen atoms in the frit, the proportion of the remaining non-oxygen atoms being less than about 37%, and 1.0 to 1.2% of cobalt atoms. In addition, there are (1) x fluorine atoms with 1%.ltoreq.x.ltoreq.11% and at least y lithium atoms and at most 2y lithium atoms with y=(15/x)+5 being present, the proportion of lithium atoms being from about 6.3% to 20% relative to the overall total of the non-oxygen atoms in the frit, or (2) y lithium atoms with 6.3%<y.ltoreq.

Abstract: Fluorine-free titanium white enamel frits for enamelling steel consisting essentially of:35 to 45 parts by weight of the sum of SiO.sub.2 and ZrO.sub.2,18 to 22 parts by weight of TiO.sub.2,18 to 22 parts by weight of the sum of B.sub.2 O.sub.3 and Al.sub.2 O.sub.3,15 to 18 parts by weight of alkali metal oxides,2.5 to 4.5 parts by weight of P.sub.2 O.sub.5, and0.8 to 1.4 parts by weight alkaline earth metal oxides;with the proviso that the ratio of atomic numbers is as follows:(A+2B) to C is 0.9.+-.0.05,(lithium+0.5 magnesium) to phosphorous is 1.+-.0.1, and sodium to potassium is 1.2 to 2.6,wherein A is the sum of monovalent atoms, B is the sum of divalent atoms and C is the sum of trivalent atoms.

Abstract: An enamel frit which provides improved bonding at stoving temperatures below 800.degree. C. after the frit has been stoved on unalloyed steel which is capable of being enamelled, the frit containing 1 to 6% by weight, based on the total quantity of the frit, of bonding oxides and the other constituents so chosen that the following equation is fulfilled: ##EQU1## in which the deviation from the ratio 1:1:1 is at most .+-.8% for each of the monovalent atoms, divalent atoms and pentavalent atoms.The enamel frits according to the invention being useful for electrostatic powder application.

Abstract: A panel heating element comprising (a) a metal substrate, (b) an aluminum boron-silicate insulating glass which forms a coating on the metal substrate, (c) one or more metallic resistance tracks applied to the substrate and (d) a mixture of a zirconium phosphate glass and a boron-titanium enamel which is applied as a layer over the metallic resistance tracks.

Abstract: The present invention relates to metal substrates which are coated with electrically insulating layers whose electrical resistance has a low temperature dependence, the insulating layer on said metal substrates consisting essentially of a melted-on material containing 43-47% by weight of B.sub.2 O.sub.3, 29-33% by weight of CaO, 10-15% by weight of SiO.sub.2, 7-10% by weight of Al.sub.2 O.sub.3 and 1-2% by weight of MgO.

Abstract: In the electrostatic spraying on metal substrates of mixtures of different inorganic powders which differ in density, particle size and electrical resistance, the improvement which comprises first forming uniform agglomerates as the different powders, and then spraying the uniform agglomerates. This prevents color variation due to separation of different powders.

Abstract: In a two-layer enamelling process in which the ground coat and surface coat powders are electrostatically applied to metallic substrates and subsequently baked together, the improvement which comprises employing a ground coat powder having an electrical resistivity of about 10.sup.10 to 10.sup.14 ohm. cm and a surface coat powder having an electrical resistivity of about 10.sup.14 to 10.sup.16 ohm. cm. Advantageously the surface tension of the ground coat amounts to at least about 0.280 N/m and the surface tension of the surface coat to at most about 0.260 N/m, the difference between the surface tensions of the ground coat and surface amounts to at least about 0.050 N/m, the ground coat powder has an electrical resistivity 10.sup.12 to 10.sup.14 ohm. cm and at least about 10.sup.2 ohm.

Abstract: An electric furnace for the continuous melting of frits for inorganic oxidic surface coatings, comprising a substantially rectangular melting chamber, a working chamber separated from the melting chamber by an immersion dam, means for the introduction of raw materials to the melting chamber, and electrodes within the melting chamber for the transmission of electrical energy to the melt, the ratio of the effective electrode surface area to the area of the bottom of the melting chamber being less than about 0.1. Advantageously the supply of energy to the electrodes is regulated by supplying a constant current with a constant output stream, the surface of the melt is covered with about 1 to 10 mm of unmelted frit, the average dwell time of the melt in the furnace is from about 3 to 6 hours, the frit is free from nitrates, the melt is about 5 to 20 cm deep and the frit is introduced thereto from a height at least 50 cm above the level of the melt.