Imperial Chemical Industries Limited

Frederick A Waite

Herbert Brooks

James D Birchall

John Cooper

James A Enever

Derek A Palgrave

Desmond W Osmond

Norman Douglas Smith

Julian A Waters

John S Roberts

Improved rate of dissolution in liquid hydrocarbon fuels, of specified tert-butylstyrene copolymers capable of imparting anti-misting characteristics to the fuel, is obtained when the copolymer, following its production by aqueous emulsion polymerization of the monomers, is isolated from the resulting latex by a process of flocculation, separation, washing and drying at moderate temperatures. The copolymer thus isolated is advantageously incorporated in the liquid fuel in the form of a slurry with a hydroxylic liquid and an amine.

Modification of liquid hydrocarbons

A fluid fertilizer composition based essentially on potassium chloride and an ammonium phosphate prepared by a process which comprises comminuting a solid substance containing potassium chloride and ammonium phosphate by grinding in the presence of a saturated solution of solid in a liquid in which the solid has a solubility greater than 1% by weight, the mixture of the solution and the solid being in fluid condition with the solid being a separate phase during grinding and the solution having dissolved therein an additive which is a crystal growth inhibitor for the solid whereby crystal growth is inhibited at both existing crystal surfaces and new crystal surfaces created by the breaking down of relatively coarse particles.

Fluid fertilizer composition

Sterically stabilized aqueous polymer depersions of at least 20% solids content are made by free radical-initiated polymerization of monomers in an aqueous medium at a temperature at least 10.degree. C. higher that the glass transition temperature of the polymer to be formed, in the presence of a pre-formed amphipathic block or graft copolymer which contains in the molecule a component solvatable by the medium and another component capable of associating with the polymer particles formed, the conditions being such that there is at no time present a separate monomer phase. The dispersions are useful as a basis of improved aqueous coating compositions.

Manufacture of aqueous polymer dispersions and coating compositions

Modified liquid hydrocarbon fuel, in particular aviation kerosene, having a reduced tendency to undergo mist formation when subjected to shock, contains from 0.05% to 2% of its weight of polymer microgel particles of defined characteristics, the microgel polymer preferably being an addition copolymer of one or more main monomers with a minor proportion, e.g. 0.0005% to 0.1% of the total monomers, of one or more monomers which are multifunctional with respect to the polymerization reaction.

Modified liquid hydrocarbons

A process is described for the production of copolymers derived predominantly from a monomer, e.g. tert-butylstyrene, having a very low solubility in water, by low temperature emulsion polymerization in a medium consisting substantially of water alone, under specified reaction conditions; high levels of conversion of monomer are achieved. The copolymer products are useful as additives to liquid hydrocarbon fuels for the purpose of reducing the tendency of the fuels to disseminate into mists under conditions of shock.

Production of copolymers using shortstop agent at end of polymerization

Copolymers are described of at least 75% by weight of tert-butyl styrene, from 1% to 24% by weight of a copolymerizable second monomer and from 1% to 10% by weight of methacrylic acid, the copolymers having certain specified solubility and rheological characteristics in AVTUR 50 aviation kerosene. A process for making the copolymers by aqueous emulsion polymerization of the monomers under certain defined conditions is also described. The copolymers are useful as additives to liquid hydrocarbon aircraft fuels for the purpose of reducing the tendency of such fuels to form inflammable mists under shock conditions.

Copolymers

Specified copolymers of tert-butylstyrene are dissolved in a liquid aliphatic hydrocarbon fuel, especially an aircraft fuel, by the steps of (i) blending the finely-divided copolymer with a non-solvent hydroxylic liquid miscible with the fuel, (ii) mixing the blend into the fuel so as to give a copolymer concentration of 01.-1% by weight, and (iii) dissolving in the fuel so treated an amino compound in an amount of 0.01-0.6 mole per 100 g of copolymer present. The copolymers thus dissolved impart to the fuel a resistance towards mist formation when the fuel is subjected to conditions of shock.

A slurry composition based essentially on ammonium nitrate, prepared by a process which comprises comminuting solid substance containing ammonium nitrate by grinding in the presence of a saturated solution of solid in a liquid in which the solid has a solubility greater than 1% by weight, the mixture of the solution and the solid being in fluid condition with the solid being a separate phase during grinding and the solution having dissolved therein an additive which is a crystal growth inhibitor for the solid whereby crystal growth is inhibited at both existing crystal surfaces and new crystal surfaces created by the breaking down of relatively coarse particles.

Ammonium nitrate slurry compositions

Specified copolymers of tert-butylstyrene are dissolved in a liquid aliphatic hydrocarbon fuel, especially an aircraft fuel, by the steps of (i) blending the finely-divided copolymer with a non-solvent hydroxylic liquid miscible with the fuel, (ii) mixing the blend into the fuel so as to give a copolymer concentration of 0.1-1% by weight, and (iii) dissolving in the fuel so treated an amino compound in an amount of 0.01-0.6 mole per 100 g of copolymer present. The copolymers thus dissolved impart to the fuel a resistance towards mist formation when the fuel is subjected to conditions of shock.

A process is described for the comminution of a solid material in the presence of a saturated solution of the solid in a liquid in which the solid has a solubility greater than 1%, and also in the presence of an additive dissolved in the saturated solution which can at least partially inhibit regrowth at crystal surfaces of the solid material. The process is of particular interest for the comminution of water-soluble salts in the presence of their saturated aqueous solutions and may be employed to make, inter alia, improved slurry explosives and fluid fertilizer compositions.

Comminution process

The dissemination of gas turbine engine aviation fuels under shock conditions, particularly by forming mist particles, and the accompanying fire hazard, are reduced by dissolving in the fuel a soluble polymer of molecular weight greater than 10.sup.6 in such concentration that there is molecular overlap of the dissolved polymer in the fuel, the dissolved polymer being one containing polar groups which form bonds with each other when the fuel is subjected to shock.

Polymer solution

A polymer is dissolved in a liquid hydrocarbon fuel which has a flash point of at least 90.degree. F and is of a type suitable for gas turbine aircraft engines in order to reduce the tendency of the fuel to particulate dissemination when the fuel is subjected to shock. The polymer has a viscosity average molecular weight greater than 10.sup.6 or an intrinsic viscosity greater than 2.5 dls./gm. and the amount of polymer is sufficient that there is molecular overlap of polymer molecules in the liquid.

Growing community of inventors

Farnham Common, United Kingdom

Frederick A Waite