Ethyl Corporation

Albemarle Corporation

David N Roark

Adam Nugent, Jr

Baldev K Bandlish

Edwin D Hornbaker

Robert L Davis

William E Wright

Wesley C Blocker

Michael J Sanders

Jules A Lambert

Pranab Choudhury

This invention describes a method for stabilizing bromine biocides in water. A water-soluble bromide salt and a sulfamate source are added to a body of water, and then an oxidant is added to the body of water to form the biocidal bromine species.

Sulfamate stabilization of a bromine biocide in water

Copolyimides and their precursors are disclosed comprising units having aromatic sulfone and aromatic fluoroaliphatic groups. These copolymers are represented by the formula ##STR1## wherein Ar' and Ar' are the same or different and are ##STR2## where Z is a chemical bond, ##STR3## Ar is the tetravalent residue of a tetracarboxylic acid or acid dianhydride or di- or tetraester thereof where the ratio of x to y is from about 1:99 to about 49:51. These copolymers have improved processing temperatures and can be readily formed into sheets. They may also be used in applications such as hot-melt adhesives or prepregging.

Copolyimide aromatic sulfone-fluoroaliphatic resin composition

A water-soluble salt of monoallylamine is polymerized in an aqueous reaction medium at a temperature of about 30.degree.-80.degree. C. in the presence of a polymerization initiator comprising about 3-15% by weight of hydrogen peroxide and about 1-700 ppm of a multi-valent metal ion, based on the weight of the monomer charge. The hydrogen peroxide is preferably introduced continuously or periodically during a substantial portion of the polymerization reaction. Preferred sources of the metal ion are water-soluble iron salts, such as ferric or ferrous chloride.

Process for polymerizing monoallylamine

Thermoplastic polyimides of benzophenone tetracarboxylic acid or an ester or anhydride thereof and a 2,2-bis[4-(amino-phenoxy)phenyl]hexafluoropropane are excellent adhesives for bonding polyimide films to various substrates including polyimide film, metals, etc. The film and substrate need not be abraded before application of the polyamic acid resin or polyimide precursor from which the polyimide is formed on curing. The bond is tenacious. Even after heating to 800.degree. F. the bond was stronger than two different polyimide films. Interposing between the polyimide film and the substrate a strip or patch of a prepreg made from polyimide precursor solutions composed of monomers, solvent and polyamide acid, and applying heat to cure the resin in situ while keeping the components in intimate contact by application of slight pressure is a preferred way of applying and utilizing the adhesives. Such prepregs are also useful for bonding metal to metal or to various other substrates.

High temperature adhesive for polymide films

A polymer of monoallylamine, preferably a water-soluble polymer of monoallylamine, whether in free (i.e., unneutralized) form or in salt (i.e., partially or completely neutralized) form is used in conjunction with a sulfonated polymer such as a water-soluble lignosulfonate, condensed naphthalene sulfonate, or sulfonated vinyl aromatic polymer, to minimize fluid loss from the slurry during subterranean well cementing operations. The polymer of monoallyl amine may be a homopolymer or a copolymer, and may be crosslinked or uncrosslinked. These components interact with each other in the presence of water to produce a gelatinous material that tends to plug porous zones and minimize premature water loss from the well cement slurry when present in the subterranean well formation. In addition, the gelatinous material so formed prevents de-stabilization of the slurry in the well formation.

Fluid loss control in well cement slurries

Water-soluble polymers of monoallylamine are employed to coalesce suspended particulate matter in aqueous dispersions. This enables rapid and efficient separation between coalesced solids and the aqueous medium by any of a variety of conventional physical techniques such as settling and decantation, filtration, centrifugation, and the like.

Water clarification

A water-soluble polymer of monoallylamine is used as a demulsifying agent for breaking oil-in-water emulsions. This enables rapid and efficient separation between the aqueous phase and the liquid organic phase by a variety of conventional physical techniques such as settling and decantation, centrifugation, and the like.

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Baton Rouge, LA, United States of America

David N Roark