Abstract:
A process for preparing a copoly(arylene sulfide) corresponding to the structure[(--A--S--).sub.1-x (--A--S--S--).sub.x ].sub.nwherein x is in the range of 0.5 to 0.001 by reacting a mixture of a diiodoaromatic compound and elemental sulfur in the absence of a basic material and in the presence of a catalytic amount of iron.
Abstract:
A process for the separation of a mixture of diiodonaphthalene isomers into an adsorbed component and a non-adsorbed component by passing the mixture over a zeolite to obtain an adsorbed zeolite containing the adsorbed component, separating off the non-adsorbed component and eluting the adsorbed zeolite with a desorbent to obtain the adsorbed component.
Abstract:
A process for preparing an aromatic carboxylic ester and an alkyl iodide by carbonylating an aromatic iodide in the presence of an ether, a catalytic amount of a transition metal and a strong acid promoter.
Abstract:
Disclosed is a process for iodinating an aromatic compound over a zeolite catalyst containing a deactivation modifier selected from the group consisting of ions or salts of hydrogen, copper, zinc, cadmium, silver and mercury.
Abstract:
A copoly(arylene sulfide) corresponding to the structure[(--A--S--).sub.1-x (--A--S--S--).sub.x ].sub.nwherein x is in the range of 0.5 to 0.001 prepared by reacting a mixture of a diiodoaromatic compound and elemental sulfur.
Abstract:
This invention relates to a novel carbonylation process for the production of aromatic carboxylic acids or esters of aromatic. More particularly, this invention relates to a process for the carbonylation of aromatic iodides or bromides with carbon monoxide in the presence of a palladium catalyst promoted with a Group VIB carbonyl and in the presence of an alcohol or water in a base reaction medium having a pKa greater than about 8. When the alcohol is used the product is the ester. When water is used the product is the carboxylic acid.
Abstract:
The present invention provides a process whereby by-product isophthalic acid is easily removed from terephthalic acid. The process thus provides a terephthalic acid product of improved purity. The process involves cooling at least a portion of a hot acetic acid production stream from which precipitated terephthalic acid has been removed so as to precipitate at least a portion of the isophthalic acid dissolved therein. The precipitated isophthalic acid is then removed and the production stream is recycled to a reactor from the production of terephthalic acid. The total production stream is thereby rendered unsaturated in isophthalic acid. Following the reaction in the terephthalic acid reactor, pure terephthalic acid in the substantial absence of isophthalic acid is recovered from the production stream as a precipitate. In a preferred embodiment, the cooling step involves cooling about 15 to 75%, and, at times, perhaps up to 100%, of the total hot acetic acid production stream to a temperature below about 50.degree. C.
Abstract:
A polymer additive for improving the reheat characteristics of a polymer or polymeric composition comprises an inorganic material which is such that a 2.5 mm thick polyethylene terephthalate plaque incorporating the inorganic material has, when tested, an absorption ratio of less than 0.9, wherein the absorption ratio is either the ratio of A1/A2 or the ratio A1/A3, wherein: A1 is the maximum absorption between 400 nm and 550 nm; A2 is the maximum absorption between 700 to 1100 nm; A3 is the maximum absorption between 700 to 1600 nm. Preferred inorganic materials are titanium nitride, indium tin oxide and lanthanum hexaboride.
Abstract:
Polymer compositions, for example of polyethyleneterephthalate bottles or preforms, include a reheat additive which has reducing transmission/increasing absorbance across the IR region as the wavelength increases. The reheat additive may be a titanium nitride, made by a plasma vapor deposition technique. Advantageously, the material may be used at a lower level than hitherto known materials or may be used at the same levels as hitherto but provide a greater reheat effect. Example 3a shown in the figure illustrates the absorbance of a preferred material.