Patent GB-960743-A (GB)
Title: Copolymers having self-cross-linking properties
IPC: C08F20/60
Filed: 1962-08-02
Abstract: A storage-stable composition of matter comprises an aqueous dispersion of a linear co-polymer of at least one ethylenically unsaturated compound containing at least one terminal CH2=C< group in the molecule and between 0.5-50% by weight (calculated on the total weight of monomers) of at least one compound of the general formula I: <FORM:0960743/C3/1> in which R1 is a hydrogen atom, a methyl group or a chlorine atom, R2 is an alkyl radical, an aryl radical, a cyclo alkyl radical or an aralkyl radical, R3 is a hydrogen atom, an alkyl radical, an aryl radical, a cycloalkyl radical or an aralkyl radical or the grouping: <PICT:0960743/C3/1> represents a heterocyclic ring system.  R2 and/or R3 are preferably alkyl radicals containing from 1 to 8 carbon atoms, or R2 and R3 together represent an alkylene group -(CH2)n-where n is 3, 4 or 5.  The residue: <PICT:0960743/C3/2> may represent a heterocyclic ring system of the formulae: <FORM:0960743/C3/2> Compounds of the above general formulae in which R2 is an alkyl radical containing 1 to 8 carbon atoms and R3 is a hydrogen atom are also of interest.  It is also possible to use mixtures of compounds of the above general formula I. Ethylenically unsaturated monomers which may be copolymerized with the compounds of the general formula I may be one of the following class of compounds (a) a -b  olefinically unsaturated monocarboxylic acids and their derivatives, (b) aromatic vinyl compounds, (c) aliphatic vinyl and vinylidene compounds, (d) conjugated diolefines containing 4 to 6 carbon atoms, (e) methylol compounds of acrylic acid and methacrylic acid amide of the general formulae II: <FORM:0960743/C3/3> in which R is a hydrogen atom or a methyl group, R1 is a hydrogen atom or an alkyl, aralkyl or aryl group and R2 is an alkyl or cycloalkyl group, (f) Mannich basis of acrylic acid and methacrylic acid amide of the general formula III: <FORM:0960743/C3/4> in which R and R1 have the same meaning as in formula II and R3 and R4 represent alkyl, cycloalkyl or aralkyl groups or together represent a heterocyclic radical.  Monomers having a cross-linking effect and containing several olefinically unsaturated groups may also be added in quantities of 0.01-10% calculated on the total weight of monomers. The aqueous co-polymer dispersions of the present invention are obtained by co-polymerizing the above mentioned monomers in aqueous dispersion using 0.5-20% by weight calculated on total weight of monomer of cationic or anionic or non-ionic emulsifying agents or combinations thereof.  Polymerization is preferably carried out at temperatures below 50 DEG C. and a pH of 3-9. Re-emulsifiable lattices are obtained by co-polymerizing the above-mentioned monomers in aqueous dispersion at a pH of 4-6 and a temperature of between 20-50 DEG C. with olefinically unsaturated monomers containing hydrophilic groups, using non-ionic emulsifying agents, and then adjusting the dispersion obtained to a pH value of between 6.5-9. 0.01-5% by weight based on total weight of monomer of a peroxide catalyst is used as the polymerization catalyst. The co-polymers of the dispersions can be converted into insoluble cross-linked products under mild conditions and are thus suitable for the manufacture of shaped articles of any kind, such as coatings, impregnations of paper, leather and adhesives.  For this purpose the dispersions are adjusted to an acid pH, preferably 2-5 by means of acids or acidifying compounds, and the dispersion in then applied to a suitable support from which the water is evaporated at temperatures greater than 80 DEG C. and the polymers are thereby cross-linked.  It is also possible to effect cross-linking merely by heating to temperatures of 80 DEG -200 DEG C.  Specifications 898,967 and 960,742 are referred to.