摘要:
A refrigeration working fluid composition which is miscible or partially miscible at temperatures of less than 120 °C and which is immiscible at temperatures of at least about 120-180 °C, the refrigeration working fluid comprising: (i) about 65 to 95 weight % of a refrigerant, based on the total weight of the working fluid composition, the refrigerant comprising a blend of pentafluoroethane, 1,1,1-trifluoroethane, and 1,1,1,2-tetrafluorothane, wherein the tetrafluoroethane is present in an amount of between about 0.5 to 10 weight %, based on the total weight of the refrigerant, and (ii) about 5 to 35 weight % of a polyol ester lubricant, based on the total weight of the working fluid composition.
摘要:
Superbase zinc soaps in the form of zinc carboxylates, in which the carboxylic acids consisting of a mixture or otherwise of satured organic carboxylic acids containing from 7 to 13 carbon atoms, having the following characteristics: a linear acid content of between 0 and 40 % by weight, a content of acids which are branched on carbon 2 of between 0 and 20 % by weight, and a content of acids which are mono- or polysubstituted on carbon 3 and/or on the carbons of higher rank, which is equal to or greater than 50 % by weight; their preparation and use as polymer stabilisers particularly for polyvinyl chloride.
摘要:
Esters of branched C9 alcohols suitable as plasticizers are formed by esterification of a C9 alcohol produced by the aldol condensation from propanal and a C6 aldehyde and hydrogenation, the propanal optionally having been made from natural gas streams.
摘要:
The present invention relates to colloidal suspensions of discrete particles of colloidal zeolite and a method for preparing such zeolite from clear tetraalkylammonium stabilized aluminiumsilicate solutions. Smaller amounts of well defined and controlled metal hydroxide solutions are added to these alumiumsilicate solutions to enable the synthesis of a specific zeolite as well as to control zeolite yield. The colloidal suspensions are characterized by an average particle size of less than 250 nanometers and preferably, less than 200 nanometers together with the fact that the particle size distribution expressed as the geometric standard deviation is less than 1.30 and preferably less than 1.20. Zeolite sols synthesized according to this invention display Tyndall light scattering typical for colloidal suspensions as well as a very low rate of sedimentation due to the small particle size. Zeolite sols synthesized according to this invention can be prepared so as to contain negligable amounts of amorphous material.
摘要:
The invention provides a continuous process for catalytically polymerizing a monomer feed of ethylene and at least one comonomer which comprises introducing a catalyst including a bulky ancillary ligand transition metal compound and monomer feed in an upstream reaction zone for polymerization, introducing further catalyst in a downstream reaction zone for further polymerization, the peak temperature in the downstream reaction zone being at least 50 °C higher than in the upstream zone and being above 100 °C. The process economically produces polymer of good properties which is melt processable.
摘要:
The disclosure concerns Ziegler-Natta catalysts. Specifically, magnesium and titanium containing catalysts are disclosed that do not exhibit a well known effect, the 'comonomer effect'. This effect manifests itself in decreasing activity with decreasing amounts of comonomer in a 1-olefin polymerization. Through the use of magnesium chloride, the effect is shown to be substantially reduced. Further, even where there are comonomers present, the catalysts of this invention show improved catalyst activity in the presence of magnesium chloride.
摘要:
A biodegradable lubricant which is prepared from: about 60-99% by weight of at least one biodegradable synthetic ester base stock which comprises the reaction product of: a branched or linear alcohol having the general formula R(OH)n, wherein R is an aliphatic or cyclo-aliphatic group having from about 2 to 20 carbon atoms and n is at least 2; and mixed acids comprising about 30 to 80 molar % of a linear acid having a carbon number in the range between about C5 to C12, and about 20 to 70 molar % of at least one branched acid having a carbon number in the range between about C5 to C10 and wherein no more than 10% of the branched acids used to form the biodegradable synthetic ester base stock contains a quaternary carbon; wherein the ester base stock exhibits the following properties: at least 60% biodegradation in 28 days as measured by the Modified Sturm test; a pour point of less than -25 DEG C.; a viscosity of less than 7500 cps at -25 DEG C.; and oxidative stability of up to 45 minutes as measured by HPDSC.
摘要:
Fiber produced from high density (>0.940 g/cm3) polyethylene resins. The resins have a MWD less than 3.6, a melt index in the range from 4 to 1000, and a M¿z?/Mw ratio less than 2.2. Both homopolymers and copolymers of ethylene may be used in this invention. The fibers may be formed by the spunbonded, meltblown or melt spinning processes and may be used to form fabrics and garments.
摘要:
Sulphonates are prepared by the neutralisation of a sulphonic acid with a basic hydroxide or oxide. The process requires the staged addition of sulphonic acid to a reaction mixture comprising basic hydroxide or oxide dispersed in a water/diluent mixture; the reaction mixture is basic throughout the additions of acid and at least until the point of completion of the neutralisation reaction. The basic hydroxide or oxide may also be added in stages. The sulphonate product has low viscosity, low haze and good stability and is essentially chloride free as halide promoters are not utilised in the manufacture of the product.
摘要:
A living carbocationic catalyst composition comprising an initiator of a tertiary alkyl halide, a tertiary aralkyl halide or polymeric halide a co-initiator of a methylaluminum or methylboron compound, and a solvent medium with a dielectric constant between 2.5 and 7 is used to produce narrow molecular weight distribution polymers particularly isobutylene polymers.