| abstract |
ABSTRACT OF THE DISCLOSURE The present invention relates to a surfactant that is soluble in an acidic aqueous medium. This surfactant is useful as an emulsi-fier particularly as an emulsifier for the preparation of latex polymers for example the latex polymerization of vinyl acetate. The copolymers of the present invention have 3 very low level compared to compounds of the prior art of ethylenically unsatu-rated monomer which contains a sulfonic acid (or its salt) substi-tuent. The use of such low levels of the sulfonate containing monomer is advantageous since such monomers are expensive. The surfactant is a copolymer containing the groups , , and , and having one R-Z- group and one -H group as terminal groups wherein R is a hydrocarbon group Z is -S-, or ; R1 is -CO2CH3, -CO2C2H5, -CONH2 or -CN; each R2 each R3 each R4 each R5 and each R7 may bs the same or different and each R2, R3, R4, R5 and R7 is either hydrogen or methyl; R6 is a group of the formula -V-CO2H or its salt wherein V is alkyl, aryl aralkyl or alkaryl; W is a group containing a sulfonic acid or a salt of a sulfonic acid or W is a sulfonic acid group or its salt. |