Abstract: A high-purity naphthalenedicarboxylic acid is produced by a method including Steps [1] and [2]: In Step [I], a raw mixture of crude terephthalic acid and crude naphthalenedicarboxylic acid is dissolved into high-temperature high-pressure water to form a dibasic acid solution wherein the crude naphthalenedicarboxylic acid content is 0.1 to 10 mass percent of the crude terephthalic acid content, the dibasic acid solution is brought into contact with hydrogen in the presence of a catalyst. In Step [II], the resultant in the dibasic acid solution is crystallized by multiple stages while the temperature and the pressure are reduced for each stage, and acid mixtures containing enriched naphthalenedicarboxylic acid or enriched terephthalic acid are obtained by solid-liquid separation.
Abstract: Naphthyloxyalkyl(meth)acrylate monomers having a high refractive index and whose respective homopolymer has a low glass transition temperature.
Abstract: Methods and devices for controlling the reaction rate and/or reactivity of a hydrocarbon to an intermediate oxidation product, such as an acid, within predetermined limits, are disclosed. Control of the reaction rate and/or reactivity within predetermined limits is achieved by monitoring and controlling the oxidant consumption rate. According to the present invention, examples of ways to determine the oxidant consumption rate include, but are not limited to, monitoring the flow rates of incoming and outgoing oxidant, monitoring pressure differentials after temporarily ceasing entry and exit of gases, and monitoring the flow rates of incoming and outgoing gases, and monitoring the rates of incoming and outgoing hydrocarbon.
Type:
Grant
Filed:
February 19, 1999
Date of Patent:
September 11, 2001
Assignee:
RPC Inc.
Inventors:
David C. DeCoster, Eustathios Vassiliou, Mark W. Dassel, Sharon M. Aldrich, Ader M. Rostami
Abstract: A process is described for producing ester quats of the formula (I) ##STR1## where X.sup.- is an anion of an inorganic or organic acid, R.sub.a is a C.sub.1 to C.sub.4 alkyl group, R.sub.b and R.sub.c are each, independently of one another, a C.sub.1 to C.sub.3 alkylene group, and R.sub.d is a C.sub.1 to C.sub.22 fragment of a saturated and/or unsaturated aliphatic carboxylic acid, m, n, p, and q are integers, m has a value from 1 to 3, n a value from 0 to 3, p a value from 0 to 1, m+n+p=4, and q has the value 1 or, if m=3, n=0, and p=1, the value 2, in which process a quaternary compound of the formula (II) ##STR2## where X.sup.-, R.sub.a, R.sub.b, R.sub.c, m, n, p, and q have the above meanings, is esterified, in the presence of an oxo acid of phosphorus and/or one of its alkali or alkaline-earth salts as a catalyst, with a saturated and/or unsaturated C.sub.1 to C.sub.22 carboxylic acid, alone or in a mixture, while withdrawing water.
Type:
Grant
Filed:
December 8, 1998
Date of Patent:
December 26, 2000
Assignee:
Akzo Nobel NV
Inventors:
Manfred Bergfeld, Hartmut Ahrens, Axel Carstens