Abstract: An energy-polymerizable composition derived from ingredients comprising: a cyanate ester monomer or oligomer comprising an organic radical bonded through aromatic carbon atoms to at least two --OCN groups; a low molecular weight polyalkylene glycol; and an organometallic compound in which at least one carbon atom of an organic group is bonded to a metal atom. The composition can be cured by at least one of thermal energy, radiation, and accelerated particles, to produce a cured, homogeneous composition.

Abstract: Distortion control additives are disclosed which comprise a polyisocyanate, a polyol or polyol blend having a hydroxyl functionality of 2 to 3 hydroxyl groups per molecule and an average molecular weight of at least about 500 grams per gram mole, a diol chain extender having from about 2 to 35 carbon atoms per molecule and an acrylate or methacrylate having an acrylate functionality of from 1 to 5 acrylate groups per molecule. Ultraviolet-curable liquid compositions comprising an unsaturated polymeric resin, a monomer and the distortion control additives of the present invention are also disclosed. The distortion control additives can provide substantial reductions in distortion, e.g., shrinkage, of objects produced by ultraviolet curing, eg., stereolithography.

Abstract: This invention relates to mixtures of urethane prepolymers of allophanate-modified diphenylmethane diisocyanates with epoxides. The addition of the epoxide increases the reactivity of these prepolymers. It is now possible to form polyurethanes from these mixtures based on prepolymers of diphenylmethane diisocyanates wherein less catalyst is necessary.

Abstract: Insoluble supports are prepared which possess high surface areas and efficiently dispersed isocyanate groups. These reactive supports are useful for covalently binding proteins which preferably are enzymes and provide catalysts for conducting organic reactions.

Abstract: The present invention relates to a process for obtaining PAI fibres by spinning PAI in solution and to the fibres thus obtained. They are obtained by dry or wet spinning into dimethylalkyleneurea followed by removal of the solvent and overdrawing at high temperature. The yarns and fibres obtained are produced from PAI based on tolylene or meta-phenylene diisocyanate, and on an aromatic acid anhydride and/or an aromatic dianhydride, and optionally on one or a number of diacid compounds. They exhibit an outstanding thermomechanical behavior and make it possible to gain access to very low linear densities.

Abstract: A polyisocyanate composition, comprising:A) from 55 to 87% by weight of a polyisocyanate which contains uretdione groups;B) from 10 to 30% by weight of blocking agent,C) from 3 to 30% by weight of polyol having more than two hydroxyl groups and/or chain extender having more than two hydroxyl groups, wherein the polyisocyanate contains more than two terminal, partially or fully blocked isocyanate groups and has a molecular weight of from 1000 to 10,000.

Abstract: A room temperature curing polyurethane composition comprises a polyisocyanate compound or polyurethane prepolymer (A), an oxazolidine compound (B) having at least one oxazolidine ring, a compound (C) for accelerating the opening of the oxazolidine ring, and optionally a modified carbodiimide (D). The inventive polyurethane composition excels in storage stability and freedom of foaming when curing.

Abstract: A method for the anionic polymerization of a lactam which produces an nylon having a surface resistivity of between about 10.sup.6 to about 10.sup.12 .OMEGA./.quadrature.. Miscible antistatic agents are mixed with the lactam and the moisture concentration in the lactam is adjusted to about 0.4 wt %. When required to complete the polymerization, the initiator concentration in the lactam is adjusted to about 1 wt %.

Abstract: An energy-polymerizable composition derived from ingredients comprising: a cyanate ester monomer or oligomer comprising an organic radical bonded through aromatic carbon atoms to at least two --OCN groups; a low molecular weight polyalkylene glycol; and an organometallic compound in which at least one carbon atom of an organic group is bonded to a metal atom. The composition can be cured by at least one of thermal energy, radiation, and accelerated particles, to produce a cured, homogeneous composition.

Abstract: This invention relates to solid elastomeric polyurethanes prepared by reacting, in an open mold at an isocyanate index of 80 to 120,(a) an isocyanate prepolymer having an isocyanate content of 3 to 15% by weight and a number average molecular weight of 550 to 20,000 prepared by the reaction of(1) organic polyisocyanates having 2 to 3 NCO groups, and(2) isocyanate-reactive polyester polyols having two to three isocyanate-reactive hydroxyl groups and a number average molecular weight of 400 to 10,000 and prepared in the presence of an esterification catalyst, and optionally containing other isocyanate-reactive compounds,wherein the equivalent ratio of isocyanate groups to isocyanate-reactive groups is 1.2:1 to 34:1;(b) a diol chain extender, optionally in admixture with a crosslinker and/or an amino-containing chain extender and/or crosslinker;(c) 0.001 to 10% by weight, based on the weight of the isocyanate prepolymer, of a catalyst; and(d) 0.

Abstract: This invention relates to novel light stable elastomers which exhibit good dynamic properties, and a process for their preparation. These elastomers comprise the reaction product of an isocyanate propolymer, a chain extender, and a catalyst selected from i) solid delayed action catalysts having a melting point of greater than about 60.degree. C., ii) alkyl substituted organotin catalysts containing alkylmercaptide ligands, and which are liquid at room temperature, and iii) alkyl substituted organotin catalysts containing sulfur bridging groups, and which are liquid at room temperature.

Abstract: Liquid polyamine crosslinking agent formulations based on trimerized toluylene 2,4- and/or 2,6-diisocyanate, with formation of an isocyanurate structure and hydrolysis of the isocyanate groups to amine groups, are described. The novel crosslinking agent formulations have a content of 40 to 80% of the total weight of the solids content of the crosslinking agent formulation of 1,3,5-tris-(3-amino-4-methyl-phenyl,2-methyl-3-aminophenyl) isocyanurate (I) which is not further condensed, and a content of not more than 1.0% of the total weight of the crosslinking agent formulations of toluylene-2,4- and/or -2,6-diamine (III). For the preparation, toluylene diisocyanate is trimerized, to form the isocyanurate structure, until 10 to 25% of the NCO groups have been reacted.

Abstract: A process, and the product produced thereby, for preparing a polyurea foam which comprises reacting an aliphatic polyamine having an average functionality from about 2 to about 6 wherein about 55 to about 95 percent of the functional groups are primary amine functional groups and about 5 to about 40 percent of the functional groups are primary or secondary hydroxyl groups with a polyisocyanate in the presence of a blowing agent that comprises water. The use of polyether polyamines having primary hydroxyl groups improves the cross-linking characteristics of the polyurea foam.

Abstract: The use of polyol derivatives with at least two alcoholic hydroxy groups and at least one fatty acid residue per molecule obtainable by reacting a starting polyol with a fatty acid or a fatty acid derivative, which can be obtained by using as a starting polyol diethanolamine, triethanolamine, diisopropanolamine, triisopropanolamine, dibutanolamine, and reaction products of ethylene oxide and/or propylene oxide with ethanolamine, isopropanolamine, butanolamine, or primary or secondary, aliphatic or aromatic amines, as internal lubricants and/or polyol with internal lubricant properties in the production of molded polyurethane parts is described. In this manner a much more uniform distribution of the internal mold lubricant and thus an increase in the ductility of the reaction mixture can be achieved, and even crosslinked polyurethane profiles can be produced by extrusion.

Abstract: Poly(ether-urethanes) can be made from cyclic ethers and organic isocyanates by using selected metal compounds as catalysts. Polymers useful as thermoplastic elastomers, spandex fibers or urethane rubbers can be made by reacting diisocyanates containing functional groups with a tetrahydrofuran, especially tetrahydrofuran itself. The invention also discloses an improved process for the cationic polymerization of a cyclic ether by using an organic isocyanate.

Abstract: 4,4'-disubstituted bis(2,6-diisopropylphenyl)carbodiimides of the formula (I) ##STR1## where R is 1-methyl-1-phenylethyl, phenoxy or tert-butyl, a process for their preparation, their use as stabilizers against hydrolytic degradation of polyaddition and polycondensation products containing ester groups, and the novel 4-(1-methyl-1-phenylethyl)-2,6-diisopropyl-, 4-phenoxy-2,6-diisopropyl- and 4-tert-butyl-2,6-diisopropylphenyl isocyanates which can be used for their preparation.

Abstract: A process and a polyurethane material for molding a semi-rigid integral skin foam which comprising an integral skin having a low degree of foaming and a core having a high degree of foaming. The process includes evacuating a mold cavity to reduce the pressure thereof below atmospheric pressure; injecting into the evacuated mold cavity a polyurethane material; and foaming the material to fill the cavity. The polyurethane material contains a polyol component and an isocyanate component with, at most, 5 parts by weight of a solvent for 100 parts by weight of the polyol component, in the absence of freon.

Abstract: The present invention relates to a coating composition having an improved pot life without a corresponding increase in dry time when cured under ambient conditions which containsa) a polyisocyanate component,b) an aldimine based on the reaction product of a polyamine having 2 or more primary amino groups with an aldehyde corresponding to the formula:O=CHCH(R.sub.1)(R.sub.2)wherein R.sub.1 and R.sub.2 may be the same or different and represent optionally substituted hydrocarbon radicals, or R.sub.1 and R.sub.2 together with the .beta.-carbon atom form a cycloaliphatic or heterocyclic ring andc) 0.001 to 5 weight percent, based on the weight of components a) and b), of a tin(IV) compound which is a catalyst for the reaction between isocyanate groups and hydroxyl groups,wherein components a) and b) are present in an amount sufficient to provide an equivalent ratio of isocyanate groups to aldimine groups of 0.5:1 to 20:1.

Abstract: 4,4'-disubstituted bis-(2,6-diisopropylphenyl)carbodiimides of the formula (I) ##STR1## where R is 1-methyl-1-phenylethyl, phenoxy or tert-butyl, a process for their preparation, their use as stabilizers against hydrolytic degradation of polyaddition and polycondensation products containing ester groups, and the novel 4-(1-methyl-1-phenylethyl)-2,6-diisopropyl-, 4-phenoxy-2,6-diisopropyl- and 4-tert-butyl-2,6-diisopropylphenyl isocyanates which can be used for their preparation.

Abstract: A sprayable polyurethane composition containing an isocyanate component and a polyol component is provided, wherein the polyol component includes a polyether polyol amine; a nitrogen-free hydoxy-terminated polyether; and a sucrose-polyether polyol. Preferably, these two components are combined while spraying them individually into a mold along with a fibrous-reinforcing material.

Abstract: An optical sensor is provided for measuring the pH of a fluid sample. The sensor is formulated using a fluorescent polymer composition comprising a copolymer of a water-dispersable, polyether-containing urethane olefin precursor and a fluorescent monomer species, wherein the ratio of precursor and fluorescent monomer species is such that a predetermined apparent pKa is provided. The sensor is prepared by coating the distal end of an optical waveguide with the fluorescent polymer composition, and curing the copolymer contained in the composition, e.g., by exposure to radiation of a suitable wavelength.

Abstract: The present invention relates to solutions which can be directly shaped in anhydrous dimethylalkyleneurea, based on a polyimide obtained from an aromatic dianhydride and an aromatic diisocyanate.It also relates to the process for the production of the above solutions, as well as to a process for spinning these solutions and to the yarns and fibres thus obtained.

Abstract: This invention concerns a reaction system for producing a polyurethane having an isocyanate index value of at least 100, and a catalyzed reaction mixture thereof, having a gel time between 5 and 60 minutes. The reaction system, in one aspect, involves a mixture of first and second parts that are located in separate containers, respectively, which are effective to prevent contact between said first and second parts thereof until coating or sealing application is desired. This two-part reaction system includes:(a) a first part comprising a polyisocyanate component; b) a second part comprising: (i) a polyol component; (ii) a polyurethane catalyst comprising a bismuth/zinc polyurethane catalyst; and (iii) a molar excess of a complexing agent for the polyurethane catalyst, where the complexing agent is a mercaptan compound. This invention also concerns a method of forming a polyurethane sealant on a surface using the two-part reaction system and catalyzed reaction mixture.

Abstract: A diaminourea compound having the formula (I); ##STR1## wherein R.sub.1 and R.sub.2 are independently a straight or branched alkylene group having 2 to 8 carbon atoms, an alicyclic alkylene group having 6 to 15 carbon atoms, a phenylene group, a C.sub.1 -C.sub.4 alkyl-substituted phenylene group, a C.sub.1 -C.sub.4 mono- or di-alkylene substituted phenylene group, or a methanediphenylene group, and a production process thereof as well as a high heat resistant polyurethaneurea derived therefrom and a production process thereof.

Abstract: A thermosetting resin composition which comprises (A) a resin in which at least one compound having a graft-reactive group such as a carboxyl group, a primary amino group or a secondary amino group and a carboxylic anhydride group has been grafted on a polycarbodiimide and (B) an epoxy compound. The said thermosetting resin composition retains heat resistance, electrically insulating properties and mechanical properties characteristic of polycarbodiimide, is excellent in solubility in various solvents and storage stability in the form of a solution and can be easily cured under mild conditions, and can produce a cured product excellent in humidity resistance, transparency, chemical stability and adhesiveness to various substrates.

Abstract: Disclosed are certain aromatic polycarbodiimides. Also disclosed is the use of an aromatic polycarbodiimide containing only aromatic carbodiimide groups as a cross-linker for a coating binder polymer bearing carboxyl groups.

Abstract: The present invention relates to textile printing pastes containing modified polyisocyanates, modified polycarbodiimides, or trifunctional polyepoxides as crosslinking agents for the binders present therein.

Abstract: The invention relates to prepolymers containing isocyanate groups which can be prepared by reactinga) organic isocyanates withb) polyetherols containing at least 2 hydroxyl groups per molecule and having molecular weights of greater than 400 and/or polyesterols containing at least 2 hydroxyl groups per molecule and having molecular weights of greater than 400,c) isocyanate-reactive compounds which are at least difunctional and have molecular weights of from 18 to 399, and, if desired,d) Lewis and/or Bronsted acidic compounds ande) conventional auxiliaries and additives, such as antioxidants, light stabilizers or fillers,wherein at least one aromatic aminopolyether alcohol of the formula ##STR1## where R is aryl, alkylaryl containing one or more C.sub.1 - to C.sub.4 -alkyl groups, haloaryl, nitroaryl or cyanoaryl,R' and R" are identical or different and are, independently of one another, hydrogen, alkyl, aryl, aralkyl, alkoxyalkyl, alkoxyaryl or aroxyaryl,x and y are independent of one another andx+y.gtoreq.

Abstract: Catalysed, cationic compositions which contain one or more catalysed, cationic binders which can be diluted in water after being protonated and which contain one or more bismuth salts of hydroxycarboxylic acids are disclosed. The bismuth salts of lactic acid and dimethylolpropionic acid are particularly preferred, and the compositions are useful in cathodically precipitated paints.

Abstract: A process for the production of rigid polyurethane foams involves reactinga) organic and/or modified organic polyisocyanates withb) at least one relatively high-molecular-weight compound containing at least two reactive hydrogen atoms, and, if desired,c) low-molecular-weight chain extenders and/or cross-linking agents,in the presence ofd) blowing agents,e) catalysts and, if desired,f) assistants and/or additives,where the relatively high-molecular-weight compounds (b) containing at least two reactive hydrogen atoms are polyoxypropylene-polyols and/or polyoxyethylene-polyoxy-propylene-polyols containing up to 20% by weight, based on the weight of the alkylene oxide units, of pendant oxyethylene units containing secondary hydroxyl groups and having a functionality of from 3.8 to 4.1, a hydroxyl number of from 385 to 410 mg of KOH/g and a viscosity of from 1700 to 2400 mPa.multidot.s at 25.degree. C.

Abstract: A linear segmented polyurethaneurea having a degree of branching (Nb) of 3 or less and obtained by chain-extending a prepolymer with an organic diamine in an organic solvent comprising dimethylformamide or dimethylacetamide, wherein the prepolymer has an isocyanate group at the both ends thereof and comprises a stoichiometrically excessive amount of a diisocyanate component selected from 4,4'-diphenylmethane diisocyanate, 2,4-toluene diisocyanate and 1,4-phenylene diisocyanate and a diol component having a number average molecular weight of 500 to 6000.

Abstract: 4,4'-disubstituted bis-2,6-diisopropylphenyl)carbodiimides of the formula (I) ##STR1## where R is 1-methyl-1-phenylethyl, phenoxy or tert-butyl, a process for their preparation, their use as stabilizers against hydrolytic degradation of polyaddition and polycondensation products containing ester groups, and the novel 4-(1-methyl-1-phenylethyl)-2,6-diisopropyl-, 4-phenoxy-2,6-diisopropyl- and 4-tert-butyl-2,6-diisopropylphenyl isocyanates which can be used for their preparation.

Abstract: Closed cell polyurethane foams, useful as thermal insulation for refrigerators and the like, are prepared by blending a polyisocyanate, a polyol and a suspension of at least one solid alkaline reagent, preferably sodium hydroxide, in an inert carrier liquid having a suitable viscosity. Preferred carrier liquids include polyepoxides and polyoxyalkylenediamines. The alkaline reagent reacts with and removes the carbon dioxide employed as a blowing agent, thus decreasing the thermal conductivity of the foam.

Abstract: A process for the preparation of polyurethane foams, preferably semirigid polyurethane foams, having an improved foam structure involves reactinga) organic and/or modified organic polyisocyanates withb) polyhydroxyl compounds containing at least 2 reactive hydrogen atoms andc) crosslinking agents which comprise at least one polyoxyalkylene-polyol having a mean functionality of from 3 to 8 and a hydroxyl number of from 200 to 1300 ppm and a content of alkali metal ions of from 150 to 1200 ppm,in the presence ofd) blowing agents,e) if desired catalysts,f) inorganic and/or organic acids as additives andg) if desired auxiliaries.

Abstract: This invention relates to a process for coating a substrate comprising contacting the substrate with a low volatile organics, moisture curable, two-component coating composition comprising an admixture of an A-side and a B-side, said A-side comprising an aliphatic polyisocyanate having an isocyanate index relative to the number of isocyanate-reactive groups in said coating composition of at least about 200, preferably at least about 300, more preferably at least about 500, said B-side comprising a tertiary amine catalyst and optionally an isocyanate-reactive compound selected from the group consisting of monoahls, polyols, imines, oxazolidines, and combinations thereof, said coating composition optionally containing a solvent in an amount of less than about 45%, based upon the weight of the polyisocyanate in said coating composition, said coating composition having a viscosity as measured by ZAHN cup 2 of less than about 200 seconds, said composition being essentially free of any volatile mono- and di-isocyan

Abstract: A sealing material is prepared by furnishing a liquid composition comprising a polydiene or polyolefin polyol, a polyisocyanate compound, a foam stabilizer, and a blowing agent, uniformly dispersing an inert gas in the liquid composition by mechanical agitation to form a bubbled composition, shaping the bubbled composition into a sheet shape, and heat curing the bubbled shape at a temperature below the decomposition temperature of the blowing agent. The sealing material is lightweight and has a high blowing magnification. On use, the sealing material is disposed in a cavity of an automotive pillar or similar member and heated for foaming to fill the cavity with the foamed product.

Abstract: The invention concerns allophanic acid derivatives of formula IR.sup.1 --N(R.sup.2)CO--N(R.sup.3)CO--X.sup.1 --Q--X.sup.2 --GIand pharmaceutically acceptable metabolically labile esters or amides thereof, and pharmaceutically acceptable salts thereof, in which R.sup.1, R.sup.2, R.sup.3, X.sup.1, Q X.sup.2 and G have the meanings given in the specification. The invention also concerns processes for the preparation of the allophanic acid derivatives of formula I, pharmaceutical compositions containing them and their use as inhibitors of the binding of fibrinogen to glycoprotein IIb/IIIa.

Abstract: This invention relates to a branched fractal three dimensional porous polymer species which comprises rigid aromatic recurring units having electrophilic or nucleophilic reactive moieties on the exterior thereof. Another aspect of this invention relates to a star polymer comprising a polymeric core formed of the fractal polymers (FPS) of this invention having linear polymeric moieties grafted to the exterior thereof by way of residues formed by reaction between the reactive moieties on the exterior of the fractal polymer (FP) and complimentary reactive moieties on a linear polymer. Yet another aspect of this invention relates to polymeric composites comprising a polymer matrix having dispersed therein the star polymers of this invention.

Abstract: The invention concerns allophanic acid derivatives of formula IR.sup.1 --N(R.sup.2)CO--N(R.sup.3)CO--X.sup.1 --Q--X.sup.2 --GIand pharmaceutically acceptable metabolically labile esters or amides thereof, and pharmaceutically acceptable salts thereof, in which R.sup.1, R.sup.2, R.sup.3, X.sup.1, Q, X.sup.2 and G have the meanings given in the specification. The invention also concerns processes for the preparation of the allophanic acid derivatives of formula I, pharmaceutical compositions containing them and their use as inhibitors of the binding of fibrinogen to glycoprotein IIb/IIIa.

Abstract: Disclosed herein is a process for producing an integral skin polyurethane foam which comprises expanding a reacting mixture containing substantially no blowing agent in an evacuated mold cavity. Disclosed also herein is an apparatus for producing said an integral skin polyurethane foam which comprises a mold having a cavity and a vent hole, a vacuum chamber communicating with the cavity through the vent hole, a vacuum pump to evacuate the cavity through the vacuum chamber, and a sight glass attached to the vacuum chamber so as to make the vicinity of the vent hole visible from the outside of the vacuum chamber.

Abstract: A composition is disclosed for transferring and adhering tape-mounted hisogical sections, to specimen mounting surfaces, usually glass microscope slides to expedite and simplify the safe removal of the mounting tape and the subsequent processing of the slide-mounted section. The composition is a curable polymeric mixture which has high tack prior to curing, is substantially non-diffusable and non-flowable into tissue sections and, after curing, has a refractive index substantially similar to that of the specimen section and is non-labile to conventional histological solvents and stains. A preferred composition comprises diacrylate-terminated polyurethane, a diacrylate ester of an epoxy resin and a diethoxyacetophenone initiator. It is usually formed onto the mounting surface as a solution in a conventional organic solvent, such as isopropanol or toluene.

Abstract: Disclosed herein are processes for the production of allophanate-modified diphenylmethane diisocyanate prepolymers and the products produced by the processes which are both stable and liquid at 25.degree. C. by reacting (i) 4,4'-diphenyl-methane diisocyanate containing from 2 to 60% by weight 2,4'-MDI and less than 6% by weight of the 2,2'-MDI with (ii) an aromatic alcohol containing between 6 and 18 carbon atoms such as phenol, with the resulting product being converted to the allophanate having an isocyanate group content of from 12 to 32% by weight.

Abstract: The present invention relates to coating compositions which are suitable for preparing matt coatings and containA) an aqueous polymer dispersion which is capable of forming films at temperatures below 70.degree. C. andB) an aqueous polyurethane polyurea dispersion which is not film forming below 70.degree. C. and preferably has an average particle diameter above 350 nm, preferably from 500 to 1000 nm.The present invention is also directed to textile or leather substrates coated with these coating compositions.

Abstract: This invention relates to a polyurea-imide RIM composition, molded articles of a polyurea-imide RIM composition, and a method of forming a polyurea-imide molded article.

Abstract: Described are compositions protected against thermal and oxidative degradation that compriseA) a polyether polyol or mixtures of such polyols,B) at least one benzofuranone derivative of formula I, ##STR1## wherein L, G, m, R.sub.1 to R.sub.5 and R.sub.21 to R.sub.24 are as defined in claim 1,C) at least one compound from the group of the phenolic anti-oxidants, and/orD) at least one compound from the group of the amino anti-oxidants of the secondary amine type. Also polyurethane(s) (foam(s)) prepared therefrom are protected against thermal and oxidative degradation, especially against core scorching.

Abstract: This invention provides methods for producing a high-molecular weight polycarbodiimide solution from an organic diisocyanate in the presence of a carbodiimidation catalyst, wherein 1) a chlorinated aliphatic hydrocarbon or 2) an alicyclic ether is used as a solvent. This invention also provides a polycarbodiimide solution with excellent stability in preservation.

Abstract: Affinity matrices useful for the chromatography and immobilization of biological materials and the method of preparing and using the same are disclosed. The affinity supports are based on hydrated polyurethane polymers which have been activated to provide a means for covalently attaching a variety of bioaffinity agents. The hydrated polymer matrices are characterized by their biocompatibility and resistance to nonspecific protein adsorption. Preferably, the prepolymers used to prepare the hydrated polymers are isocyanate-capped oxyethylene-based diols or polyols, at least 75% of said diols and polyols having a molecular weight of 7000 to about 30,000.

Abstract: A process for inhibiting chemical reactions of a fluid functionally reactive organic material by mixing it with supercritical fluid ("SCF") or near supercritical fluid, especially carbon dioxide maintained under supercritical fluid conditions. The process includes the ability to restrain a chemical reaction that occurs otherwise between functionally compatible organic molecules by the inclusion of supercritical fluid, particularly CO.sub.2, with the molecules, so that the reaction can be made to occur according to a predetermined but different from normal pattern.

Abstract: Adhesives and sealants, based on polyurethane reactants, are provided. The one-component frozen premix material of the invention comprises: (a) up to about 60 vol % of at least one filler; (b) about 0.5 to 5 wt % of a thixotrope comprising hydrophobic fumed silica; and (c) the balance a urethane matrix. The urethane matrix comprises at least one polyol that includes at least one carbon-carbon double bond in its backbone and has less than 20 wt % of ether and ester moieties, at least one aliphatic polyisocyanate in stoichiometric amount relative to the polyol, and about 0.01 to 0.1 wt % of an organo-metallic catalyst. The urethanes of the invention can be stored as one-component, frozen, premix materials for a minimum of three months, and, when thawed, can be applied with a spatula or trowel to form non-sag fillets. The cured elastomers are free of voids, tears, or bubbles.

Abstract: The variations in the delivery rate of additive caused by fluctuations in a system for the preparation of a polyurethane reaction mixture from flowable reactants and an additive, in particular a blowing agent, are kept within negligible limits by subdividing the supply pipe (4) to the mixing head (6) into a main pipe (8) and a subpipe (9) and introducing the additive into the side stream, which is substantially smaller than the main stream.