Abstract: A continuous process for the preparation of aromatic diisocyanates by phosgenation of the corresponding diamines, in which the reaction is carried out in the gas phase. The mean contact time for the gaseous reactants is from 0.5 to 5 seconds with a mean deviation of no more than 6%. The product diisocyanate is obtained in yields of over 95%.

Abstract: Pure isocyanate is recovered from an isocyanate-containing residue of a phosgene/amine reaction mixture by continuously feeding such residue and a high boiling hydrocarbon such as bitumen to a heated vacuum drier with a horizontal shaft. The contents of the drier are subjected to temperatures of from about 160.degree. to about 280.degree. C. and pressures of from about 2 to about 50 mbar. Pure isocyanate and a pourable, non-dusting, granular material are recovered.

Abstract: Substituted 4-amino-1,2,4-triazine-5-ones are purified to remove unwanted N-isomers by maintaining the crude product at a temperature of from about 55.degree. C. to about 70.degree. C. in the presence of a hydroxide, preferably an alkali metal hydroxide for at least 0.5 hour.

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: Storage stable, liquid prepolymers of diphenylmethane diisocyanate containing urea and/or biuret groups are prepared by reacting an aminocrotonate with a mixture of isocyanates having a specified diphenylmethane diisocyanate isomer content. These prepolymers have isocyanate group contents of from about 5 to about 30%.

Abstract: An isocyanate terminated prepolymer based upon diphenylmethane isocyanates. This prepolymer is the reaction product of a diphenylmethane isocyanate mixture having from about 75 to about 95 wt % binuclear isomers and from about 5 to about 25 wt % polymeric isocyanate with a polyether polyol. The binuclear isomer content is generally from about 15 to about 40 wt % 2,4'-isomer and from about 2 to about 10 wt % 2,2'-isomer. The polyether polyol has a functionality of from about 3 to about 8, an OH number of from about 350 to about 1000 mg KOH/g and a molecular weight of from about 150 to about 1000. These prepolymers are particularly useful as starting materials for the production of light-colored, dimensionally stable rigid polyurethane foams.

Abstract: Rigid polyurethane foams are produced by reacting an organic polyisocyanate with an amine-based polyether polyol in the presence of a catalyst, a hydrogen-containing fluorocarbon and a minor amount of water. These foams are characterized by K-factors which are about 0.135 BTU-in./hr.ft..sup.2 .degree.F. or less.

Abstract: Substantially closed-cell rigid foams containing urethane, urea and biuret groups are produced by reacting an NCO terminated prepolymer with a compound having at least two isocyanate-reactive hydrogen atoms and a molecular weight of from about 400 to about 10,000 in the presence of a catalyst and water by any of the known techniques. The NCO terminated prepolymer is the reaction product of x parts by weight of an at least difunctional polyol having an OH value of less than 100 with y parts by weight of an at least difunctional polyisocyanate. The ratio of x to y is at least 1:10. The product foams are particularly useful as insulating materials.

Abstract: An epoxide is produced by reacting a sulfonium salt with a ketone in the presence of a low molecular weight alcohol or ether and an alkali metal hydroxide at a temperature of from about 60.degree. to about 90.degree. C. The alkali metal hydroxide is in the solid form. The reaction is generally carried out in the presence of an organic solvent such as toluene. The preferred low molecular weight ether is diethylene glycol. Water is not added to the reaction mixture.

Abstract: Sucrose-based polyether polyols which do not promote degradation of HCFC blowing agents are produced by blocking at least 10% of the polyol's hydroxyl groups with a compound represented by the formula CH.sub.3 COCH.sub.2 COOR in which R represents an alkyl group. These polyether polyols are particularly useful in the production of polyurethane foams.

Abstract: An environmentally safe, multi-wall disposable bag for a granulated pesticide which is made of: a) a first outer bag composed of paper having a closed end, an open end, an inner, uncoated surface and an outer surface, and b) a second bag composed of a water soluble material having a closed end, an open end, an inner surface and an outer surface which is positioned within outer bag a) in a manner such that in the open position, its opening extends beyond that of outer bag a).

Abstract: A device for establishing an ambient temperature correction having (a) at least one reference surface which adequately represents the black body radiation spectrum of the air column between a long-path FTIR spectrometer and the infra-red source and (b) at least one means for shielding the reference surface from external sources of radiation gain or loss. In a preferred embodiment, the reference surface is made of thin metal having a blackened surface surrounded by an insulating shield. It is also preferred that a means for promoting positive air circulation across the reference surface or surfaces be included in the device of the present invention. This device is positioned in a location such that the field of view of the long-path FTIR spectrometer will be covered.

Abstract: A substantially linear poly-vinylarene/polyurethane block copolymer prepared by reacting (1) a difunctional poly-vinylarene which is produced by anionic polymerization and which contains isocyanate-reactive groups, (2) a diisocyanate or an isocyanate prepolymer, and (3) a diol having a high molecular weight or a chain extender having a lower molecular weight, is disclosed to be suitable for the preparation of shaped articles, coatings, coupling agents and compatibilizers.

Abstract: A process for the preparation and purification of nitroaromatics by nitration of the corresponding aromatics and subsequent melt crystallization. The residual melts which occur are recycled.

Abstract: A process for the production of flexible polyurethane foams by the reaction of a polyol and water with polyisocyanate in the presence of a blowing agent, the improvement wherein the polyisocyanate includes toluene diisocyanate having a 2,4-isomer to 2,6-isomer ratio is greater than 80:20. The invention encompasses a process for increasing softness of flexible foams by reacting a secondary hydroxyl terminated polyol with a polyisocyanate in the presence of a blowing agent of carbon dioxide derived from the polyisocyanate/water reaction, a substantially low amount of an auxiliary blowing agent, and the polyisocyanate including toluene diisocyanate having a 2,4-isomer to a 2,6-isomer ratio greater than 80:20. It has been found that by the present invention that there is obtained flexible polyurethane foams having the unexpected properties of 15% to 23% softening, increased tear strength, increased tensile strength, and increased percent elongation, and very little change in compression set properties.

Abstract: The present invention encompasses an improved process for preparing polymethylene polyphenyl polyisocyanate comprising reacting phosgene with polymethylene polyphenyl polyamine, the improvement wherein the polymethylene polyphenyl polyamine is acidified prior to phosgenation.

Abstract: A process for the solvent-free production of hydroxy-functional copolymers by copolymerization of unsaturated monomers in a mixture of a polyester component and an unsaturated ester component as reaction medium, the use of the hydroxy-functional copolymers so obtained as binder component in polyurethane powder coatings, a powder coating based on these copolymers and its use for coating any heat resistant substrates.

Abstract: N-alkoxysilylalkyl-aspartic acid esters are prepared by the reaction of equimolar quantities of amino-alkyl alkoxysilanes with maleic or fumaric acid esters. These N-alkoxysilylalkyl-aspartic acid esters are particularly useful as reactants in the preparation of prepolymers containing alkoxysilane and urea groups.

Abstract: A process for the production of pure distilled isocyanates in which the corresponding amine is reacted with phosgene in a suitable solvent and working up of the isocyanate containing solution obtained by multistage distillation into pure isocyanate, pure solvent and a residue. The residue is then charged to a vessel containing at least one hydrocarbon having a high boiling point. The contents of this vessel are then heated with stirring to distill off any free isocyanate present. The remaining residue is a solid which may be disposed of readily.

Abstract: Organic carbodiimides are produced by carbodiimidization of isocyanate groups with catalysts of the phospholine type. At the end of the carbodiimidization reaction, the catalyst system is removed by introducing carbon dioxide in vacuo at temperatures of from about 100.degree. to about 250.degree. C. The carbodiimides produced by this process are particularly useful as stabilizers for plastics.