Patent GB-1066893-A (GB)
Title: Production of a thermoplastic material ionically linkable with water
IPC: B29C48/395
Filed: 1966-03-24
Abstract: A melt stable homogenous thermoplastic material that may be ionically linked by contact with water is prepared by reacting (1) a copolymer having at least 50 mol. per cent of hydrocarbon monomer units of the formula -CHR-CH2-, where R is H, C1-8 alkyl or phenyl, 0.2 to 25 mol. per cent of alpha, beta ethylenically unsaturated carboxylic acid units, and a melt index of from 0.1 to 1000g/10 minutes with (2) the free calcium oxide of a Portland cement containing up to 5% by weight free calcium oxide, by kneading components (1) and (2) at a temperature above the softening point of the copolymer and below 275 DEG  C., thus forming water, the total amount of water initially present in components (1) and (2) being less than 3000 parts per million, and controlling the hydration of the Portland cement by reducing the amount of water present in the reaction mixture to less than 1000 parts per million within a predetermined time for the hot kneading operation of less than 30 minutes.  The copolymer may contain a third monomer component, e.g. an unsaturated ester, nitrile, alcohol, ether or halo-olefin, and may be blended with another polymer of the same or different type.  The content of cement in the cement-copolymer mixture may be from 2 to 90% by weight, preferably 10 to 40%. Removal of water from the reaction mixture can be effected by means of application of reduced pressure or by passing a dry inert gas over the mixture while continually exposing new surfaces.  The kneading operation may be carried out in two stages with different proportions of cement and copolymer in each stage. Additives such as pigments and stabilizers (unspecified) may be included during the kneading operation.ALSO:A melt stable homogeneous thermoplastic material that may be ionically linked by contact with water is prepared by reacting (1) a copolymer having at least 50 mol. per cent of hydrocarbon monomer units of the formula -CHR-CH2-, where R is H, C1- 8 alkyl or phenyl, 0.2 to 25 mol. per cent of alpha, beta ethylenically unsaturated carboxylic acid units, and a melt index of from 0.1 to 1000 g./10 minutes with (2) the free calcium oxide of a Portland cement containing up to 5% by weight free calcium oxide, by kneading components (1) and (2) at a temperature above the softening point of the copolymer and below 275 DEG  C., thus forming water, the total amount of water initially present in components (1) and (2) being less than 3000 parts per million, and controlling the hydration of the Portland cement by reducing the amount of water present in the reaction mixture to less than 1000 parts per million within a predetermined time for the hot kneading operation of less than 30 minutes. The acid component of the copolymer may be acrylic, methacrylic, ethacrylic, itaconic, maleic or fumaric acid, or a mono-ester of such a specified dicarboxylic acid, e.g. methyl hydrogen maleate or ethyl hydrogen fumarate, or an anhydride such as maleic anhydride.  A third monomer component may be present in the copolymer, e.g. a vinyl ester such as the acetate or propionate, a (meth)acrylate ester such as methyl methacrylate or ethyl acrylate, acrylonitrile, vinyl alcohol, vinyl methyl ether, or a halo-ethylene such as vinyl chloride or fluoride, vinylidene chloride or chlorotrifluoroethylene. The copolymer may be modified before being mixed with the cement, e.g. by halogenation or removing unreacted acid monomer present in the copolymer.  The copolymer may be blended with another hydrocarbon polymer of the same or different type. The copolymer-cement mixture may contain from 2 to 90% by weight of cement, preferably 10 to 40%.  Removal of water from the reaction mixture can be effected by means of application of reduced pressure or by passing a dry inert gas over the mixture while continually exposing new surfaces.  The kneading operation may be carried out in two stages with different proportions of cement and copolymer in each stage. Additives such as pigments and stabilizers (unspecified) may be included during the kneading operation.