摘要:
A preformed posterior palatal seal (Preformed PPS) for use in preparation of dentures includes a body preformed of a predetermined anatomically based size and shape of a posterior palatal seal (PPS) for sealing a denture at the "Ah line" of the human palate and adhesive for holding the preformed body to a denture impression prior to forming a mold from which a denture is to be formed.
摘要:
Polyaspartic acid is prepared by polymerization of aspartic acid, maleic acid anhydride, maleic acid or fumaric acid in a solvent at from 130.degree. C. to 300.degree. C., optionally in the presence of ammonia.
摘要:
A thermoreversible thickener comprising a water-soluble copolymer containing as constituent monomer at least 50% by weight of a vinyl carboxylic ester of a cylic amine or a non-cyclic amine with at least 5 carbons with an alkylene oxide added thereto. The thickener, with a transition temperature which can be easily controlled according to the purpose of application such as coating, rolling oil, adhesives or inks, has a characteristic such that heating the aqueous solution thereof up to a temperature above the transition temperature causes rapid thickening of the solution.
摘要:
Crosslinked, nitrogen-containing vinyl copolymers having units of the formula I ##STR1## and physiologically tolerated salts thereof, in which, in formula I, A1, A2, R, w, x, y and z have the meanings given, a process for their preparation and the use of the compounds as medicaments, active compound carriers and foodstuff auxiliaries are described.
摘要:
Alkenyl ether-siloxane compositions comprising(A) an oligomeric or polymeric organosilicon compound having on average more than one alkenyloxy group of the formulaR.sup.2 --CH.dbd.CH--O-- (VI)(B) a monomeric maleic and/or fumaric acid compound of the formula ##STR1## in which R.sup.2 is a hydrogen atom or the methyl radical,R.sup.3 is identical or different and is a hydrogen atom, a hydrocarbon radical having 1 to 16 carbon atoms, which can be interrupted by oxygen, sulfur or oxygen- or silicon-containing units, a substituted hydrocarbon radical having 1 to 6 carbon atoms, a silyl radical or a siloxanyl radical,R.sup.4 is identical or different and is a hydrogen atom, chlorine, bromine, fluorine or an optionally substituted alkyl radical andZ is an oxygen atom or a radical --NR.sup.5 --, where R.sup.5 has one of the meanings given for R.sup.3,optionally(C) initiators which form free radicals and optionally(D) inhibitors for regulating the pot life.
摘要:
The invention provides novel acrylamide functional disubstituted acetyl aryl ketones and a process for their preparation in high yields uncontaminated by difunctional material. The invention further provides photocrosslinkable compositions comprising one or more ethylenically-unsaturated monomers and as photoinitiator the acrylamide functional disubstituted acetyl aryl ketone of the invention. The compositions are useful for the preparation of films and coatings, particularly pressure-sensitive adhesive coatings.
摘要:
Salt-free vinylamine copolymers are formed by heating the corresponding N-vinylformamide copolymer to a temperature from about 75.degree. to 225.degree. C. in non-aqueous media in the presence of a catalyst comprising a Group VIII metal.
摘要:
Crosslinked, nitrogen-containing vinyl copolymers having units of the formula I ##STR1## and physiologically tolerated salts thereof, in which, in formula I, A1, A2, R, w, x, y and z have the meanings given, a process for their preparation and the use of the compounds as medicaments, active compound carriers and foodstuff auxiliaries are described.
摘要:
Crosslinked, absorbent pressure sensitive adhesive compositions are disclosed comprising an acrylate or methacrylate ester of an alcohol, a hydrophilic alkylene oxide acrylate, a hydrophilic N-vinyl lactam, and an effective amount of a crosslinking agent. The compositions have an enhanced skin adhesion profile and are moderately absorbent. Also disclosed are precursor adhesive compositions and low-profile wound dressings.
摘要:
Hydrogels presented in the form of pellets which are capable of regulating, without dissolving, any pH of an aqueous solution so as to convert it to a pH of 7. These pellets can be removed from the solution at any time without this modifying the pH, and once washed, can be used again. The velocity of buffering depends on the initial pH and can be controlled by modifying the mass and the composition of the pellets. They are obtained by copolymerization of a vinyl-heterocyclic comonomer and a divinyl comonomer in an aqueous solution at a temperature of close to 60.degree. C., in an inert atmosphere. By adjusting the proportion of crosslinking agent and the concentrations of comonomers, the crosslinking of the hydrogel is regulated in accordance with the intended use of the product.