摘要:
The free radical initiated addition polymerisation of ethylenically unsaturated, particularly acrylic monomers in which the dispersed phase is stabilised by a surfactant including at least one anionic surfactant compound of the formula (I): R1-(OA)n-X where R1 is C16 to C22 hydrocarbyl including at least two double bonds; OA is oxyalkylene group; n is from 2 to 60; and X includes at least one acidic H atom, and is particularly a phosphate ester group, or a salt thereof, is described. The use of the surfactants of the formula (I) enable efficient emulsification and thus polymerisation at temperatures above those at which non-ionic unsaturated surfactants are effective. The polymer latex products give polymer films having good water resistance properties.
摘要:
A lubricant composition for use in a rotary vane compressor has a base oil component that comprises an alkylbenzene as a major component thereof and a polyol ester as a minor component thereof. In particular, the base oil component comprises at least 55% by weight of alkylbenzene and at most 45% by weight of a polyol ester, more preferably between 55% and 75% by weight of alkylbenzene and between 45% and 25% by weight of polyol ester and, especially, between 60% and 75% by weight of alkyl benzene and between 45% and 25% by weight of polyol ester.
摘要:
A method for obtaining an approximate standard colour definition for a sample colour (2) without the need for standard conditions of illumination or observation. The method comprises using colour sensing equipment such as a digital camera (6) to sense under non-standard conditions both the sample colour and a plurality of reference colours (5) each being provided on a template (1) and each having a known standard colour definition. The sensing under non-standard conditions produces a non-standard colour definition both for the sample colour and for each of the reference colours. The non-standard colour definitions of reference colours near in colour space to the sample colour are compared with the known standard colour definitions for the reference colours to obtain correction factors which are then applied to the non-standard colour definition of the sample colour to convert it to colour definition which, though it is only an approximation of the standard colour definition, is nevertheless sufficiently close to the true standard colour definition to be useful in colour matching.
摘要:
Production of unsaturated ketones by the aldol condensation of ketones such as acetone or methyl ethyl ketone by contacting the ketone in the vapour phase with a particulate catalyst comprising at least one basic alkali metal compound supported on an inert substrate at a temperature above 175null C. The produce ketones may be hydrogenated to form saturated ketones or alcohols.
摘要:
Process for the preparation of open celled rigid polyurethane or urethane-modified polyisocyanurate foams by reaction of a polyfunctional isocyanate-reactive composition with a polyisocyanate composition comprising a prepolymer of NCO-value 21-30% based on a high molecular weight oxyethylene-containing polyol.
摘要:
A lubricant composition has a synthetic lubricant base oil, preferably a polyol ester, and a polyether foam-inducing additive. The composition is suitable for use in a refrigerant system, particularly with HFC refrigerant gases. The foam-inducing additive is an alternative to known silicon-containing foam-inducing additives, which are not suitable for all refrigerant systems.
摘要:
An aqueous emulsion of a resin which includes as an emulsifier at least one compound of the formula (I): R1nullCOnullNR2R3 wherein R1 is a polyunsaturated hydrocarbyl group; R2 is a polyhydroxy hydrocarbyl radical; and R3 is hydrogen, a hydrocarbyl, particularly alkyl, group, a hydroxy or hydrocarboxyloxy substituted hydrocarbyl, particularly hydroxy or alkoxy substituted alkyl, or is a group as defined for R2. The resin is preferably an alkyd resin, and the emulsions are particularly useful for incorporating into paints.
摘要:
An aqueous coating composition containing polymeric binder comprising particles of polyurethane-acrylic hybrid polymer dispersed in aqueous medium containing i) polyurethane polymer, preferably from 0.1 to 75 wt %, ii) copolymer of ethylenically unsaturated addition copolymerisable monomers, preferably from 25 to 99.9 wt % characterised in that the polyurethane polymer comprises the reaction product of a) a polyisocyanate b) a compound containing at least two moieties reactive with the isocyanate moieties of the polyisocyanate c) a compound containing at least one dispersing moiety and at least one moiety reactive with the isocyanate moieties of the polyisocyanate d) a chain extender compound e) a urethane diol, being the reaction product of a cyclic carbonate and a compound containing an amino group and a further group selected from amino and hydroxy, said urethane diol comprising up to 80 wt % of the polyurethane polymer. The coatings have improved abrasion, water and stain resistance. Also an aqueous dispersion and a urethane prepolymer for use in making the dispersion.
摘要:
Synthetic detergent formulations are made by spray drying an aqueous dispersion or emulsion of a synthetic detergent and a hydrophobic plasticiser and optionally a filler to pr duce a particulate product. In particular the synthetic detergent includes mild surfactants such a fatty isethionate or sulphosuccinate surfactants. By spray drying the emulsion or dispersion, a particularly uniform product is made which can readily be formed into synthetic detergent bars which may include soap to form combination bar products (combi-bars).
摘要:
The density of a mass of material is determined by passing radiation from a source, such as Co-60, whose radiation spectrum has a characteristic energy level above 700 keV through the mass of material to a detector that can detect radiation at a energy level, or range of energy levels, within the range 80 to 700 keV. By determining the density of the mass of material at different locations, the density profile of the mass of material can be assessed.