National Starch and Chemical Corporation

Minoru Tokumoto

Motoyuki Takagi

Carmine P Iovine

Samuel Gold

Shizuo Shitaoka

A method of finishing a concrete structure which comprises coating an aqueous acrylic acid esters resin emulsion including a special acrylic acid esters copolymer on the bare surface of a concrete structure and after dried, forming a cement-based finishing layer. The action of the film formed by said emulsion provides an improved adhesive bond strength between said concrete structure and the finishing layer, prevents breakage of the finishing layer almost permanently, and is, furthermore, effective in bonding the coated layers strongly, even when they are coated repeatedly.

Method of finishing a concrete structure

A cement admixture which results in a cement mortar with excellent adhesion to various adherents and with excellent flexibility over a wide range of temperatures, including very low temperatures, contains cement, optionally but preferably sand, and an effective amount of an aqueous emulsion of a cationic acrylate polymer having a Tg between below 10.degree. C. and -40.degree. C. The polymer comprises (a) about 25 to 85% of an acrylate monomer (e.g., butyl acrylate, methylmethacrylate, or 2-ethylhexyl acrylate but not methyl or ethyl acrylate), (b) about 0.5-15% of an alkaline-curable cationic quaternary ammonium salt monomer, and optional monomer(s) other than (a) or (b). The alkaline-curable cationic quaternary ammonium salt units in the polymer are represented by the formula ##STR1## where R is hydrogen or a methyl group; R.sup.2 and R.sup.3 may be the same or different and are a methyl or ethyl group: A is --O-- or --NH--; X is chlorine, bromine, or iodine; Y is an organic or inorganic monovalent anion; and n is 2 or 3.

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Nara, Japan

Minoru Tokumoto