Abstract: Process for preparing rigid and flexible polyurethane foams by reacting a polyisocyanate and a polyol in the presence of water and CO.sub.2. The foams obtained do not show a major glass transition temperature between -100.degree. C. and +25.degree. C. and have improved air flow properties.

Abstract: A heat exchange catalytic process and reactor of the shell-and-tube type having a plurality of tubes extending longitudinally through the shell from a tube fluid inlet region to a tube fluid outlet region and baffles extending transversely across the shell dividing the shell between said inlet and outlet regions into at least three heat exchange zones through which each tube passes in sequence in heat exchange with that zone. A shell fluid is passed through the heat exchange zones in heat exchange with the tube fluid passing through the tubes. Transfer passages are provided connencting the heat exchange zones and are disposed so that the shell fluid passes through the second zone before or after it has passed through both the first and third zones. A particulate catalyst is disposed in either the shell heat exchange zones or, preferably, the tubes.

Abstract: A dye diffusion thermal transfer printing dye sheet comprising a substrate having a coating comprising a dye of Formula (1): ##STR1## wherein Ch is a chromogen;R.sup.a and R.sup.b each independently is a spacer group;Y is an interactive functional group selected from the group comprising OH and COOH;w and x each independently is 0 or an integer equal to or greater than 1; andm and n each independently is an integer equal to or greater than 1, provided that w and x are not both equal to 0 and when one of w or x is 0 at least one of m and n is equal to or greater than 2 and when Y represents hydroxy, m+n is greater than 2.

Abstract: Process for making flexible polyurethane foams using MDI and TDI and a polyol composition comprising dispersed particulate material.

Abstract: A process for producing an aqueous coating composition comprising an aqueous dispersion of internally crosslinked polymer microgel particles in which the microgel articles are produced by emulsion polymerisation of ethylenically unsaturated monomers including carboxyl functional monomer in an aqueous medium so as to form an aqueous dispersion of carboxyl functional addition polymer followed by reacting this polymer dispersion with a diepoxide resin having an epoxide equivalent weight between 100 and 5000 to form the crosslinked polymer microgel particles.

Abstract: Hydrophilic flexible polyurethane foam which foam is in a compressed state above its glass transition temperature and at ambient pressure in the absence of force suitable to create the compressed state.

Abstract: Use of a mixture of at least two different polyoxyethylene polyether monols to solubilise hydrocarbon blowing agents in polyol compositions for rigid polyurethane foams.

Abstract: Prior to carrying out a gaseous phase chemical reaction, a liquid phase organic compound which is prone to degrade is vaporised at elevated pressures with the aid of a second compound. In one embodiment of the invention, vaporisation is effected by co-vaporising a mixture of the two compounds in a vaporiser. In another embodiment, the first compound is injected into a hot gaseous stream and undergoes atomisation into droplets which then vaporise within the gaseous stream. The second compound is used to assist the atomisation process and/or to sweep atomised droplets of the first compound away from hot surfaces where the first compound would otherwise tend to undergo degradation if the droplets are allowed to reside in contact with such surfaces.

Abstract: A catalyst unit for use in an exothermic reaction, such as ammonia oxidation, comprises a material effective as a catalyst for said reaction having a shape conforming to a disc or cone having a plurality of radially extending corrugations. The catalyst unit may be disposed across a reactor with a start-up burner disposed above the catalyst unit and mounted for rotation about the axis of the reactor. The burner tube is pivoted and provided with means, for example a follower engaging with the upper surface of the catalyst unit, so that as the burner is rotated about the axis the burner tube pivots to maintain the burner tube a constant distance above the upper surface of the catalyst unit.

Abstract: The present invention relates to a process for preparing a flexible polyurethane foam from the reaction of a polyisocyanate composition prepared from the reaction of an excess of organic polyisocyanate and a polyether polyol having a high ethylene oxide content and an isocyanate reactive composition comprising a chain extending agent and a combination of a polyether polyol having a high ethylene oxide content and a random copolymer having a high ethylene oxide content, and the product prepared therefrom.

Abstract: Process for preparing a flexible polyurethane foam by reacting a polyisocyanate and two different polyols under foam forming conditions so as to prepare a rigid foam, by crushing the rigid foam so obtained and by subjecting the flexible foam so obtained to a heat treatment. Flexible foams are obtained which do not show a major glass transition temperature between -100.degree. C. and +25.degree. C.

Abstract: Shaped particles suitable for use as a catalyst, or precursor thereto, particularly for the decomposition of hypohalite ions in aqueous solution, comprising a high alumina cement having an aluminium to calcium atomic ratio above 2.5 and at least one oxide of a Group VIII metal M selected from nickel and cobalt, said particles containing 10 to 70% by weight of said Group VIII metal oxide and having a porosity in the range of 30 to 60%, in which at least 10% of the pore volume is in the form of pores of size in the range 15 to 35 nm and less than 65% of the pore volume is in the form of pores of diameter greater then 35 nm are disclosed.

Abstract: Process for preparing a flexible polyurethane foam by reacting a polyisocyanate and two different polyols under foam forming conditions so as to prepare a rigid foam and by crushing the rigid foam so obtained in a direction perpendicular to the direction of rise of the foam. Flexible foams are obtained which do not show a major glass transition temperature between -100.degree. C. and +25.degree. C. and which have an anisotropy of 1.80 to 4.00.

Abstract: A cathode wherein the electrocatalytically-active outer layer is of substantially uniform thickness and has contours which are at least substantially the same as the contours of the substrate immediately underlying it. The electrode may be prepared by depositing the electrocatalytically-active outer layer by physical vapour deposition. The electrocatalytically-active outer layer comprises (a) cerium and/or cerium oxide and at least one non-noble Group 8 metal or (b) platinum and/or platinum oxide and ruthenium and/or ruthenium oxide.

Abstract: A sprayable aqueous coating composition for motor vehicles comprising an aqueous dispersion of addition polymer microparticles having a crosslinked core and a non-crosslinked stabilising mantle containing acid groups, characterised in that the crosslinked core comprises: i) a crosslinked inner core of an addition polymer and ii) a crosslinked outer core of addition polymer which is made from at least 10% by weight of monomers having a solubility in water of less than 0.1% by weight ratio of the inner core to the outer core being in the range 10:90 to 90:10.

Abstract: Pseudo-operator sequences may be located in (or inserted into) plant genomes and utilized to drive expression of foreign genes. These pseudo-operator sequences are nucleotide sequences which are present at a suitable location in a gene at which repressor binding will lead to inhibitation or enhancement of gene expression. The disclosed technique permits the design of altered specificity repressors, which bind the pseudo-operators.

Abstract: Compensation for catalyst activity decline in multi-bed selective hydrogenation of acetylenes in the presence of olefins by providing inter-bed heating so that the product from the first bed is heated before it is fed to the second bed, and the temperature at which the product from the first bed is fed to the second bed is increased as the catalyst activity declines. In a modification, when the catalyst is fresh, the product from the first bed is cooled before it is fed to the second bed, but, as the catalyst activity declines the temperature at which the product from the first bed is fed to the second bed is increased, so that after a period of use the product from the first bed is heated before it is fed to the second bed.

Abstract: A process for the purification of a fluid stream containing a sulphur contaminant, such as hydrogen sulphide, and mercury, phosphine, stibine, and/or arsenic compounds as a second contaminant wherein said fluid stream is passed through a bed of a particulate absorbent containing a sulphide of a variable valency metal, especially copper, that is more electropositive than mercury, to remove said second contaminant and then the sulphur contaminant is removed from at least part of the effluent from that bed by passing that part of the effluent through a bed of a particulate sulphur absorbent comprising a compound selected from oxides, hydroxides, carbonates and basic carbonates of said variable valency metal is disclosed. The removal of the sulphur contaminant converts said variable valency metal compound to the corresponding sulphide. The resulting bed of variable valency metal sulphide is subsequently used for the removal of the second contaminant.

Abstract: Process for making open celled (semi-) rigid polyurethane foams using as cell opening agent a fatty acid or a fatty acid amine or a fatty acid amide or a fatty acid ester.

Abstract: Process for the preparation of rigid open celled polyurethane foams comprising the step of reacting an organic polyisocyanate with an isocyanate-reactive material in the presence of a blowing promotor which is an isocyanate-reactive cyclic carbonate or cyclic urea, and in the presence of an aminoalcohol catalyst.