摘要:
Methods of producing ABO.sub.3 compounds in which A represents a first metal ion and B represents a second metal ion from mixed metal coordination complexes are disclosed. The methods involve reacting compounds serving as a source of the B metal ion with a substituted aromatic compound, in solution, and thereafter reacting the metal coordination complex formed with a compound serving as a source of the A metal, in solution. An example is the reaction of titanium tetraisopropoxide with catechol to form a titanium catecholate coordination complex which is thereafter reacted with barium hydroxide octahydrate to form a pentamethanol barium triscatecholatotitanate mixed metal coordination complex which can be calcined at elevated temperatures to produce the ABO.sub.3 compound, barium titanate (BaTiO.sub.3), which is known to have outstanding dielectric, ferroelectric and piezoelectric properties. Portions of the A and/or B ions can be substituted with other metals.
摘要:
Methods of producing ABO.sub.3 compounds in which A represents a first metal ion and B represents a second metal ion from mixed metal coordination complexes are disclosed. The methods involve reacting compounds serving as a source of the B metal ion with a substituted aromatic compound, in solution, and thereafter reacting the metal coordination complex formed with a compound serving as a source of the A metal, in solution. An example is the reaction of titanium tetraisopropoxide with catechol to form a titanium catecholate coordination complex which is thereafter reacted with barium hydroxide octahydrate to form a pentamethanol barium triscatecholatotitanate mixed metal coordination complex which can be calcined at elevated temperatures to produce the ABO.sub.3 compound, barium titanate (BaTiO.sub.3), which is known to have outstanding dielectric, ferroelectric and piezoelectric properties. Portions of the A and/or B ions can be substituted with other metals.
摘要:
Certain tetrahydrocarbylphosphonium bicarbonate salts are produced by reacting a trihydrocarbyl(hydrocarbylcarboxymethyl)phosphonium hydroxide inner salt with water. For example, methyl tri-n-butylphosphonium bicarbonate salt was prepared in quantitative yields by heating tri-n-butylcarboxymethylphosphonium hydroxide inner salt in an aqueous methanol solution at 100.degree. C. for 3 hours.
摘要:
Compounds of formulas I and II are heat-activated catalysts used in making polyurethanes. ##STR1## wherein R, R.sub.1, and R.sub.2 are each independently H, hydrocarbyl or an inertly-substituted hydrocarbyl; R.sub.3 and R.sub.4 are each independently hydrocarbyl or an inertly-substituted hydrocarbyl; and X is an anion. Upon heating, Compounds I and II catalyze the reaction and may release gaseous by-products which cause the resulting polyurethane compound to foam. For example, the catalyst, t-butyl imidazole-N-carboxylate, when heated to 120.degree. C., catalyzes the reaction between a polyol and a polyisocyanate to give a foamed polyurethane which cured in 16 minutes.
摘要翻译:式I和II的化合物是用于制备聚氨酯的热活化催化剂。 其中R,R 1和R 2各自独立地为H,烃基或惰性取代的烃基; R 3和R 4各自独立地为烃基或惰性取代的烃基; X为阴离子。 加热时,化合物I和II催化反应,并可能释放导致所得聚氨酯化合物发泡的气态副产物。 例如,催化剂叔丁基咪唑-N-羧酸酯在加热至120℃时催化多元醇与多异氰酸酯之间的反应,得到在16分钟内固化的发泡聚氨酯。
摘要:
Preparation of a ceramic green body by hydrolyzing two groups of alkoxides to form a dispersion of their reaction product, concentrating the dispersion to a sediment without drying it, and admixing a binder solution, plasticizer and release agent with the sediment to make a ceramic slip formulation. The slip formulation is then cast as a ceramic green body. The proportions of alkoxides can be adjusted to produce a ceramic green body which is dielectric and useful for microcapacitors.
摘要:
The trisubstituted (2,5-dihydroxyphenyl)phosphonium hydroxide inner salts and their hydrolyzed derivatives are novel latent catalysts for promoting reaction between vicinal epoxides and phenols and/or carboxylic acids (or anhydrides). Precatalyzed epoxy resins are easily prepared using such catalysts.
摘要:
Ar-cyclic sulfonium arenethiol salts exemplified by the formula: ##STR1## may be converted to their corresponding zwitterion, exemplified by the formula: ##STR2## The latter polymerize very readily upon exposure to mild conditions of heat or radiative energy. The resultant polymers are water-insoluble resins useful as adhesives, coatings, films and the like. The zwitterions containing more than one arenesulfide and cyclic sulfonium group per molecule, crosslink upon exposure to heat to form thermoset resins.
摘要:
The invention is the process which comprises contacting a reaction mixture comprising between about 1 and 100 percent by weight of a polyethylene-substituted piperazine, a piperazine or mixtures thereof, wherein such compounds contain a primary or secondary nitrogen wherein one of the carbons adjacent to the nitrogen has a hydrogen atom bonded to the carbon atom, and between about 1 and 99 percent of a solvent, with a catalytic amount of palladium on a support, at a temperature of between about 150.degree. C. and 300.degree. C., under condition such that the product so prepared contains polyethylene polypiperazines.
摘要:
Tetrahydrocarbyl phosphonium bicarbonate salts are employed as catalysts to promote the reaction between (a) vicinal epoxides and (b) carboxylic acids or anhydrides. These catalysts are particularly useful in the preparation of vinyl ester resins.
摘要:
Novel amide acetals of the formula ##STR1## wherein R.sub.1 is hydrogen, methyl or Y and Y is the remnant of a hydroxyl-containing compound are claimed. The compounds are useful as water scavengers in fluid compositions.