An object of the present invention is to provide magnesium oxide for an annealing separator which is useful for obtaining grain-oriented electromagnetic steel sheets with excellent magnetic properties and insulating properties. To resolve the above object, an aspect of the present invention resides in magnesium oxide for an annealing separator having a sulfur content of 0.1 to 0.5 mass % and an aggregation degree R.sub.Blaine/R.sub.BET of 3.0 to 5.5 wherein R.sub.Blaine is the particle size calculated from the Blaine specific surface area and R.sub.BET is the particle size calculated from the BET specific surface area.

The present invention relates to a low friction member having seaweed-type nanotubes, the nanotubes which protrude like seaweed on the surface of a base material being concentrated in the moving direction of a sliding member, thereby improving the fluidity of a liquid lubricant, thus enabling the effective reduction of surface friction.

Such present invention comprises: a base material which has a plurality of dimples formed on the surface thereof so as to reduce friction occurring due to the surface contact of a sliding member; a fixing material which is filled inside the dimples; nanotubes which are buried in the fixing material and protrude to the outside by means of the surface processing of the fixing material; and a liquid lubricant which is coated on the surface of the base material, wherein, as the protruding nanotubes become concentrated in the moving direction of the sliding member, the fluidity of the liquid lubricant is improved, thereby enabling the effective reduction of surface friction.

An object of the present invention is to provide magnesium oxide for an annealing separator which is useful for obtaining grain-oriented electromagnetic steel sheets with excellent magnetic properties and insulating properties. To resolve the above object, an aspect of the present invention resides in magnesium oxide for an annealing separator which has a BET specific surface area of 12.0×10.sup.3 to 25.0×10.sup.3 m.sup.2.Math.kg.sup.−1 and a Blaine specific surface area of 2.0×10.sup.3 to 7.0×10.sup.3 m.sup.2.Math.kg.sup.−1.

A grain-oriented electrical steel sheet has a steel sheet and an insulating coating which is formed on a surface of the steel sheet. In the insulating coating, a metal phosphate and a colloidal silica are contained, the colloidal silica is contained in an amount of 20 to 150 parts by mass with respect to 100 parts by mass of the metal phosphate, one or more kinds of fine particles selected from the group consisting of silicon carbide, silicon nitride, aluminum nitride, boron nitride, sialon, and cordierite are further contained in an amount of 0.5 to 7 parts by mass with respect to 100 parts by mass of the metal phosphate, an average particle size of the fine particles is 0.3 to 7.0 μm, crystallized ratio of the metal phosphate is 2% to 40%, and chromium is not contained.

A grain-oriented electrical steel sheet has a steel sheet and an insulating coating which is formed on a surface of the steel sheet. In the insulating coating, a metal phosphate and a colloidal silica are contained, the colloidal silica is contained in an amount of 20 to 150 parts by mass with respect to 100 parts by mass of the metal phosphate, one or more kinds of fine particles selected from the group consisting of silicon carbide, silicon nitride, aluminum nitride, boron nitride, sialon, and cordierite are further contained in an amount of 0.5 to 7 parts by mass with respect to 100 parts by mass of the metal phosphate, an average particle size of the fine particles is 0.3 to 7.0 μm, crystallized ratio of the metal phosphate is 2% to 40%, and chromium is not contained.

Methods for treating a substrate are disclosed. The substrate is deoxidized and then immersed in an electrodepositable pretreatment composition comprising a lanthanide series element and/or a Group IIIB metal, an oxidizing agent, and a metal-complexing agent to deposit a coating from the electrodepositable pretreatment composition onto a surface of the substrate. Optionally, the electrodepositable pretreatment composition may comprise a surfactant. A coating from a spontaneously depositable pretreatment composition comprising a Group IIIB and/or Group IVB metal may be deposited on the substrate surface prior to electrodepositing a coating from the electrodepositable pretreatment composition. Following electrodeposition of the electrodepositable pretreatment composition, the substrate optionally may be contacted with a sealing composition comprising phosphate and a Group IIIB and/or IVB metal. Substrates treated according to the methods also are disclosed.

A coating solution for forming an insulating film for a grain-oriented electrical steel sheet which contains one or more types of hydrous silicate powders having an average particle size of 2 μm or less, and one or more types of phosphoric acids and phosphates satisfying a relation of Σn.sub.iM.sub.i/ΣP.sub.i≤0.5, and satisfies (Formula 1).
1.5≤(Σn.sub.iM.sub.i+Σn′.sub.jM′.sub.j)/ΣP.sub.i≤15  (Formula 1)
(P represents the number of moles of phosphorus, M represents the number of moles of metal ions derived from the phosphate, n represents the valence of the metal ions derived from the phosphate, i represents the number of types of phosphates, M′ represents the number of moles of metal elements in the hydrous silicate, n′ represents the valence of the metal elements in the hydrous silicate, and j represents the number of types of hydrous silicates).

The invention relates to a method for zinc phosphating components comprising surfaces made of zinc in order to suppress the formation of insoluble phosphation constituents removably adhered to the zinc surfaces and thus further improve the adhesion of dip-paint coatings applied later. In the method, a process is used of activating the zinc surfaces by means of dispersions containing particulate hopeite, phosphophyllite, scholzite, and/or hureaulite, wherein the proportion of particulate phosphates in the activation process must be adapted to the quantity of free fluoride and dissolved silicon in the zinc phosphation.

The invention relates to a method for zinc phosphating components so as to form layers, said components comprising surfaces made of steel with a high tolerance against aluminum dissolved in the zinc phosphating bath, wherein the precipitation of poorly soluble aluminum salts can be largely prevented. In the method, a process is used of activating the zinc surfaces by means of dispersions containing particulate hopeite, phosphophyllite, scholzite, and/or hureaulite, wherein the proportion of particulate phosphates in the activation process must be adapted to the quantity of free fluoride and dissolved aluminum in the zinc phosphation.

The present invention relates to an eco-friendly and simple super-hydrophobic coating method that does not use harmful substances and special equipment. Coating according to the present invention may be performed as a single process without special equipment, and because only eco-friendly materials are used, the coating material may be easily used and discarded. In addition, even a three-dimensional pipe or a heat-exchanger having a complex shape may be modified to have super-hydrophobicity by applying the present coating, and a super-hydrophobic metal filter may be manufactured and used for oil-water separation. As a result, the present coating method is eco-friendly, simple, and applicable to various substrates, so it has great potential for application in various industries.