Aqueous coating-film-forming composition for forming lubricating coating film, and air bag using said composition

An aqueous coating film-forming composition for forming an antifriction dry coating film that reduces friction and/or blocking of a surface of a substrate, the composition comprising:

• (A1) a solid lubricant selected from one or more types of solid lubricants selected from the group consisting of mica, talc, kaolinite, sericite, and chlorite;
• (B1) one or more types of thickeners selected from the group consisting of (b1) water-soluble organic polymers and (b2) clay minerals, wherein the thickener comprises as a clay mineral one or more types selected from the group consisting of saponites, bentonites, and montmorillonites, and has viscosity thickening properties where the viscosity of a 2 wt % aqueous dispersion of the thickener is at least 1000 mPa-s;
• and
• (C) a silicone binder in the form of an oil-in-water silicone emulsion comprising:
• 100 parts by mass of (c3) a polyorganosiloxane having at least two hydroxyl groups or hydrolyzable groups bonded to a silicon atom in one molecule, where the viscosity at 25° C. is within a range of 100,000 mPa-s to 20,000,000 mPa-s;
• 5 to 120 parts by mass of (c4) colloidal silica, as calculated by solid fractions;
• 1 to 100 parts by mass of (c1) an ionic emulsifier;
• 0.1 to 50 parts by mass of (c2) a polyoxyethylene-polyoxypropylene copolymerized nonionic emulsifier;
• and
• 0 to 500 parts by mass of water, excluding water content in the colloidal silica (c4);
• wherein component (c3) is
• (c3a) a polyorganosiloxane having at least two hydroxyl groups or hydrolyzable groups bonded to a silicon atom serving as a precursor of component (c3) and
• (c3b) a polyorganosiloxane obtained by emulsion polymerizing an organic silicon compound containing an aminoxy group having an average of two aminoxy groups bonded to a silicon atom in one molecule, in the presence of components (c1) and (c2);
• wherein 5 to 40 mass % of the entire composition including water content is component (A1);
• and
• wherein
• if the total amount of a dry film obtained by removing water content is 100 mass %,
• the amount of solid lubricant (A1) is 40 to 80 mass %;
• the amount of thickener (B1) is 0.50 to 10 mass %;
• the amount of polyoxyethylene-polyoxypropylene copolymerized nonionic emulsifier (c2) is 0.60 to 0.97 mass %;
• and
• the amount of silicone binder (C), solid fraction, is 5 to 49.5 mass %.