Mobil Oil Corporation

Other

Rhodia Limited

Wan-Li Liu

Frederick C Loveless

Thomas S Coolbaugh

Demetreos N Matthews

Herve Adam

Frederick Charles Loveless

Herv&eacute; Adam

Ellen Bernice Brandes

A subject-matter of the present invention is a process for the preparation of a latex by radical aqueous emulsion polymerization in the presence of at least one ethylenically unsaturated monomer, of at least one radical polymerization initiator and of at least one surface-active block copolymer comprising at least one hydrophilic block and at least one hydrophobic block which is prepared by a &ldquo;living&rdquo; or &ldquo;controlled&rdquo; preparation process, the said copolymer exhibiting a number-average molecular mass of between 2 000 and 20 000, preferably between 4 000 and 16 000, a glass transition temperature of the hydrophobic block of less than 30&deg; C., preferably of less than 25&deg; C., and greater than &minus;100&deg; C., and a surface tension of less than 60 millinewtons per metre (mN/m), preferably of less than 50 mN/m, measured at a concentration in demineralized water of less than or equal to 10 mol/l at 20&deg; C. and under one atmosphere, and the transfer agent having been rendered inert with respect to the said radical polymerization. The latices obtained can be used in particular in paints, adhesives and building materials.

Process for the preparation of latices using block copolymers as surfactants

The invention relates to a process for removing a dithio group comprised at the end of a polymer chain, comprising the step of reacting a polymer comprising a dithio group at least one chain-end, with an amine compound, different from triethanol amine, in an organic solvent.

Process for removing a dithiocarbonyl group at the end of a polymer chain

Solid star-branched block copolymers wherein each branch comprises at least two (2) alternating blocks bonded to each other, the free end of each branch being a block of at least one polymerized hydrocarbon conjugated diene (I), e.g. isoprene, containing at least 5 carbon atoms, with at least one carbon atom of each pair of residual double-bonded carbon atoms of polymerized diene (I) units being additionally single-bonded to two carbon atoms, or a copolymer of a least one diene (I) and at least one aryl-substituted olefin, e.g. styrene, the blocks adjacent to said polymerized diene (I) containing blocks constituting at least 50 wt. % of said copolymer and being a polymer of at least one hydrocarbon conjugated diene (B), e.g., 1,3-butadiene, which is different from diene (I) and contains at least four (4) carbons atoms, with each residual double-bonded carbon atom of polymerized conjugated diene (B) units being additionally bonded to a hydrogen atom. After the polymerization is completed, the block copolymer may be selectively hydrogenated, so that each (B) polymer block is hydrogenated to such an extent that it contains substantially none of the original ethylenic unsaturation, while each of the (I) polymer or copolymer blocks retains a sufficient amount of its original ethylenic unsaturation to cure (or vulcanize) the copolymer.

Star-branched block elastomeric copolymers

The invention provides dispersants and dispersant viscosity index improvers which include polymers of conjugated dienes which have been hydrogenated and functionalized. The dispersant substances include compositions including a copolymer of two different conjugated dienes, a copolymer of a p-alkylstyrene and a conjugated diene, or a homopolymer of a conjugated diene. The polymers are selectively hydrogenated to produce polymers which have highly controlled amounts of unsaturation, permitting highly selective functionalization. Also provided are lubricant fluids, such as mineral and synthetic oils, which have been modified in their dispersancy and/or viscometric properties by means of the dispersant substances of the invention. Also provided are methods of modifying the dispersancy and/or viscometric properties of lubricating fluids such as mineral and synthetic lubricating oils. The dispersant substances may also include a carrier fluid to provide dispersant concentrates.

Dispersants and dispersant viscosity index improvers from selectively

There are disclosed novel comb graft polymers and copolymers comprising a backbone of a linear polymer of p-methylstyrene (p-MS) and grafted branches of a linear addition polymer of at least one anionically polymerizable compound. The polymers may be produced by metallating the p-MS polymer with an organo alkali metal metallating agent, e.g., an alkyllithium, at active hydrogen sites along the polymer chain and graft polymerizing the anionically polymerizable compound at the metallated sites to form the grafted branches. Certain of the foregoing comb graft polymers and copolymers, e.g., wherein the backbone is a homopolymer of p-MS or a copolymer of p-MS and a ring-substituted alkylstyrene such as p-tert-butylstyrene (t-BS) and the branches are a polymer of t-BS, are useful as additives to functional fluids, particularly hydrocarbon lubricating oils, for the purpose of thickening and improving their viscosity index.

Comb graft polymers and their use in functional fluids

Novel star-branched polymers in which the arms are each a polymer of an anionically polymerizable monomer consisting of monoethylenically unsaturated compounds comprising p-tert-butylstyrene (t-BS) coupled with a polyalkenyl coupling agent. Certain of the foregoing star-branched polymers, e.g., wherein the arms are a homopolymer of t-BS and the coupling agent is divinylbenzene (DVB), are useful as additives to functional fluids, particularly hydrocarbon lubricating oils, for the purpose of improving their viscometric properties.

Star-branched polymers and functional fluids prepared therefrom

A process for the preparation of a polymer concentrate which is a relatively concentrated solution in a base stock oil, e.g., a mineral oil or synthetic hydrocarbon oil, of a highly branched polymer having segments of a polymer of p-tert-butylstyrene (t-BS), comprising the free radical solution polymerization in the base stock oil of t-BS and optionally, one or more additional polymerizable monoethylenically unsaturated (monofunctional) monomers together with a small amount of a multiethylenically unsaturated (multifunctional) cross-linking agent, e.g., divinylbenzene (DVB). Optionally, the polymer solution obtained from the polymerization may be diluted with an additional amount of the base stock oil employed in the polymerization to obtain a polymer concentrate having a lower polymer concentration and viscosity than the polymerization solution. The polymer concentrate may then be mixed with an additional a amount of base stock oil which may be the same or different from the base stock oil present in the polymer concentrate to obtain a functional fluid, e.g., a lubricating oil, having improved viscometric properties.

Growing community of inventors

Yardley, PA, United States of America

Wan-Li Liu