25626-25-9

Upstream product

• 75-44-5 phosgene 
• 17300-02-6 1,2-benzenedimethanamine 
• 20236-50-4 silver (I) nitro cyanamide 
• 91-13-4 α,α'-dibromo-o-xylene 

Downstream Products

• 20628-51-7 diethyl o-xylene-α,α'-dicarbamate 

Relevant academic research and scientific papers

Storage-stable biuret polyisocyanates

Storage-stable biuret polyisocyanates useful, e.g., for the production of paints and adhesives, are prepared by reacting at least one aliphatic, alicyclic or arylaliphatic diisocyanate with a biuret-forming reactant, in the presence of an effective amount of at least one organic carboxylic acid and/or anhydride thereof.

Preparation of biureto polyisocyanates

Clear, precipitate-free, storage-stable biureto polyisocyanates, well adopted for paint applications, are prepared by reacting at least one aliphatic, alicyclic or arylaliphatic monomeric diisocyanate with water, at a temperature of at least 70° C. and under an absolute pressure of at least 1.2 bar, including a partial pressure of carbon dioxide of at least 0.2 bar.

METHOD OF PRODUCING MODIFIED ORGANIC POLYISOCYANATE

A modified organic polyisocyanate having isocyanurate rings is produced by adding a trimerization catalyst, an organic phosphite, a surfactant and, if desired, a ferrocene compound to an organic polyisocyanate and/or partially urethanated organic polyisocyanate, converting at most 20 % by weight of all of the isocyanate groups into isocyanurate groups, and adding, if necessary, a terminating agent to the reaction system.

Alkylation of Nitrocyanamide. A New Synthesis of Isocyanates

Thirteen alkyl halides (primary, secondary, and tertiary aliphatic including alicyclic, aralkyl, and heteroalkyl systems) and certain non-vicinal dihalides on treatment with silver nitrocyanamide are converted into the corresponding isocyanates (63-95percent).Intermediate alkylnitrocyanamides, spectroscopically detected, thermolysed (-20-80 deg C) to the expected isocyanates.In certain examples silver nitrocyanamide is generated in situ from sodium nitrocyanamide and silver nitrate.Silver nitrocyanamide does not react with cyclopropyl bromide, acetyl chloride, toluene-p-sulphonyl chloride, phenacyl bromide and 2-bromomethyldioxolane (27), and the ethylene acetal (28) of 1-bromo-4-iodopentacyclo-nonan-9-one.Silver nitrocyanamide reacts with 4,6-bis(bromomethyl)-3,7-dimethyl-1,5-diazabicyclo3.3.0)octane-2,8-dione (26), to give an intractable mixture.Vicinal dihalides give erratic results without detectable formation of vicinal di-isocyanates: unisolated 2-bromoethyl isocyanate (tentative assignment) has been detected in a product mixture from ethylene dibromide; an expected rearrangement during the reaction with 1,2-dibromocyclobutane, brought about the formation of 4-bromobut-3-enyl isocyanate isolated as ethyl 4-bromobut-3-enylcarbamate in low yield; and 1,2-dibromocyclohexane gives 2-bromocyclohexyl isocyanate isolated as ethyl N-(2-bromocyclohexyl)-carbamate in low yield.

Optical brightening agents of naphthalimide derivatives

A naphthalimide derivative having the formula STR1 wherein R is an alkyl, or cycloalkyl, an aralkyl, a haloalkyl, an alkoxyalkyl, a hydroxyalkyl, an N,N-dialkylaminoalkyl, an unsubstituted or halogen-, alkyl-, alkoxy- or hydroxy-substituted aryl, or an ammoniumalkyl; X is a group of the formula, STR2 wherein A is STR3 or an unsubstituted or halogen-substituted arylene, or a group of the formula, STR4 wherein R1 is hydrogen, an alkyl, phenyl, a hydroxyalkyl, or an alkoxyalkyl; Y is --CO--, --COO--, --CONR3 -- (where R3 is hydrogen or an alkyl), or --SO2 --; R2 is hydrogen, an alkyl, a cycloalkyl, an aralkyl, a haloalkyl, an alkyl- or aryl-substituted amino-alkyl, an unsubstituted or halogen-, alkyl-, alkoxy-, hydroxy-, amino- or alkylamino-substituted aryl, a group of the formula, STR5 (where R, R1 and Y are as defined above and R4 is a bivalent group), or a group of the formula, (where R5 is direct linkage or a bivalent group; Q+ is a substituted ammonium, a cycloammonium or a hydrazinium; and α- is an anion), Which is useful for optically brightening an organic polymer material.