Copolymers containing fluorine and their use for the water-repellent and oil-repellent treatment of various substrates

#The present invention relates to new copolymers containing fluorine and their use for the coating and impregnation of various substrates such as textiles, leathers, wood, non-woven materials, metals, concrete and, more particularly, papers and similar articles for making them oil and water repellent.

#A number of fluorine derivatives have already been proposed in order to obtain these properties. However, although these derivatives have good properties on textiles and on leather, it is necessary in order to obtain these same properties on papers and similar materials to use very large amounts of active substance (i.e. the proportion of fluorine connected to the carbon) so as to obtain acceptable economic performances.

#In French Pat. Nos. 1,172,664 and 2,022,351, the latter corresponding to U.S. Pat. No. 3,641,083, and in U.S. Pat. No. 3,907,576 chromium complexes have been proposed as products more especially adapted to papers. These complexes, however, which give effective oil-repellent properties to papers and similar articles, have the disadvantage of being of green color and of communicating this color to the substrates to which they are applied, thus restricting their use.

#20.4 parts of acetone, 45 parts of isopropyl alcohol, 8 parts of dimethylaminoethyl methacrylate, 16 parts of N-vinylpyrrolidone, 0.8 parts of 2,2'-azo-bis-isobutyronitrile and 81.6 parts of a mixture of polyfluoro monomers of the formula: ##STR13## where n is equal to 3, 5, 7, 9, 11, 13 and 15 in the ratios of mean weight respectively of 1:50:31:10:3:1:1, are charged into a reactor having a capacity 1000 parts by volume, provided with a stirrer, a reflux condenser, a thermometer, an inlet tube for nitrogen and a heating device. Heating is effected at 75.degree. C. for 15 hours under an atmosphere of nitrogen, then 160 parts of water, 250 parts of isopropyl alcohol and 8 parts of acetic acid are added. The mixture is then maintained for 2 hours at 75.degree. C., and then cooled to the ambient temperature.

#563 parts of a solution (S.sub.1) are thus obtained of a copolymer according to the invention. This solution contains 18.8% of non-volatile material and its proportion of fluorine is 6.6%.

#2a. Into an apparatus similar to that of Example 1 are charged 19.2 parts of acetone, 45 parts of isopropyl alcohol, 8 parts of dimethylaminoethyl methacrylate, 21 parts of N-vinylpyrrolidone, 0.8 parts of 2,2'-azo-bis-isobutyronitrile and 76.8 parts of the same mixture of polyfluoro monomers as in Example 1. The mixture is heated at 75.degree. C. for 15 hours under a nitrogen atmosphere, then 160 parts of water, 250 parts of isopropyl alcohol and 8 parts of acetic acid are added, and it is maintained for a further 2 hours at 75.degree. C., then cooled to the ambient temperature. 585 parts are thus obtained of a solution (S.sub.2) of a copolymer according to the invention. This solution contains 18.2% of non-volatile materials and its proportion of fluorine is 6%.