60 results about "Quinone methide" patented technology

The invention provides a composition of matter and a method of its use in preventing unwanted polymerization reactions. The composition comprises an inhibitor and a retarder. The inhibitor is highly effective. The retarder is reliable under extreme and emergency situations. The inhibitor can be an alkylhydroxylamine. The retarder can be a 7-cyano-quinone methide. The combination of the inhibitor and retarder has been found to be far more effective than expected.

A one-pot process of preparing a substituted 7-cyano quinone methide in which i) a substituted phenol is chloromethylated to form a substituted 4-chloromethylphenol; ii) converting the substituted 4-chloromethylphenol to a substituted 4-cyanomethylphenol; and iii) oxidizing the substituted 4-cyanomethylphenol to the substituted 7-cyano quinone methide, where steps i)-iii) are carried out in a single reaction vessel in a solvent system comprising water and one or more organic solvents and where after steps i) and ii) the aqueous portion of the reaction mixture is removed and the reagents for the subsequent step are added in aqueous solution. The 7-cyano quinone methides are effective inhibitors of the polymerization of reactive monomers.

A method of inhibiting fouling and viscosity increase in hydrocarbon streams including ethylenically unsaturated monomers is disclosed. The method includes the step of adding to the hydrocarbon stream an effective amount of one or more quinone methides of the formula: wherein R1, R2, and R3 are independently selected from the group consisting of H, —OH, —SH, —NH2, alkyl, cycloalkyl, heterocyclo, and aryl.

A one-pot process of preparing a substituted 7-cyano quinone methide in which i) a substituted phenol is chloromethylated to form a substituted 4-chloromethylphenol; ii) converting the substituted 4-chloromethylphenol to a substituted 4-cyanomethylphenol; and iii) oxidizing the substituted 4-cyanomethylphenol to the substituted 7-cyano quinone methide, where steps i)-iii) are carried out in a single reaction vessel in a solvent system comprising water and one or more organic solvents and where after steps i) and ii) the aqueous portion of the reaction mixture is removed and the reagents for the subsequent step are added in aqueous solution. The 7-cyano quinone methides are effective inhibitors of the polymerization of reactive monomers.

An olefinically unsaturated monomer is stabilized by a retarder-containing composition which comprises a solvent and a quinone methide as a retarder.

According to the present invention, there are provided a polymerization inhibitor which is easy to handle and which has a little toxicity and a high polymerization-inhibitory effect toward an aromatic vinyl compound and a process for inhibiting the polymerization of the aromatic vinyl compound. The present invention relates to a polymerization inhibitor for the aromatic vinyl compound which comprises contain two ingredients of a specific quinone methide compound and a specific organic sulfonic acid compound, and to a process for inhibiting polymerization of the aromatic vinyl compound which comprises adding a specific quinone methide compound and a specific organic sulfonic acid compound simultaneously or further a specific quinone methide compound, a specific organic sulfonic acid compound and a specific N-oxyl compound simultaneously in the stage of producing, purifying, storing or transporting the aromatic vinyl compound.

Quinone methide derivatives such as 4-benzylidene-2,6-di-tert-butyl-cyclohexa-2,5 dienone are used to inhibit styrene monomer polymerization in the dehydrogenator portion of a styrene monomer production system. The inhibitor contacts the dehydrogenation effluent and does not partition in substantial amounts to the aqueous phase that is separated in the phase separator.

The present invention relates to additive composition for control and inhibition of polymerization of styrene, wherein the composition comprises amine and quinone methide, and wherein the amine is polymerization non-inhibitor amine. In one embodiment, the present invention relates to method of preparation and use of additive composition to control and inhibit polymerization of styrene, wherein the composition comprises amine and quinone methide, and wherein the amine is polymerization non-inhibitor amine. In another embodiment, the present invention relates to additive composition for control and inhibition of polymerization of styrene, wherein the composition comprises oxide treated derivative of amine and quinone methide, and wherein the am ine is polymerization non-inhibitor amine, and to the method of preparation and use thereof.

Polymeric substrates, for example polyolefins such as polypropylene, can be made flame retardant by the incorporation therein of a synergistic mixture of (i.) at least one compound selected from the group consisting of nitroxyl stabilizers, hydroxylamine stabilizers, nitrone stabilizers, substituted hydroxylamine stabilizers, amine oxide stabilizers, benzofuranone stabilizers phosphite and phosphonite stabilizers, quinone methide stabilizers and monoacrylate esters of 2,2′-alkylidenebisphenol stabilizers and (ii.) at least one compound selected from the group consisting of brominated flame retardants, phosphorus containing flame retardants and inorganic flame retardants such as ammonium polyphosphate or decabromodiphenyl oxide; wherein the amount of organic or inorganic flame retardant of component (ii.) required to achieve an acceptable level of flame retardancy is significantly reduced compared to that needed when component (i.) is not present.

This invention relates to a process for the production of quinone methods and more particularly to a method for process which optimizes the production of quinone methide, in particular 4-Benzylidene-2,6-di-tert-butyl-cyclohexa-2,5-dienone, while limiting the production of by products or waste.

An olefinically unsaturated monomer is stabilized by a retarder-containing composition which comprises a solvent and a quinone methide as a retarder.

This invention relates to a process for the production of quinone methide and more particularly to a method for process which optimizes the production of quinone methide, in particular 4-Benzylidene-2,6-di-te / t-butyl-cyclohexa-2,5- dienone, while limiting the production of by products or waste.

The invention provides a method for synthesizing 7-Acetyleno quinone methide compounds that is safe and inexpensive. The method avoids the need for extremely cold reaction temperatures and unlike the prior art does not require any highly explosive materials. The method comprises the steps of:a) performing a condensation reaction between 3,5-di-tert-butyl-4-hydroxybenzaldehyde and a secondary amine thereby forming a secondary amine quinone methide intermediate;b) removing water from the secondary amine quinone methide intermediate by azeotropic distillation;c) adding the dehydrated secondary amine quinone methide intermediate to an organic medium containing a metal acetylide to form a Mannich base intermediate; andd) adding a release agent to the Mannich base intermediate to yield a 7-Acetyleno quinone methide.

The present invention generally relates to compounds and methods for inhibiting the radical polymerization of unsaturated compounds, particularly vinyl monomers. More particularly, it relates to the use of cinnamyl quinone methides to inhibit the polymerization of unsaturated hydrocarbon compounds (e.g., vinyl monomers) soluble in organic solvents, particularly hydrocarbon streams.

The present invention provides a method for inhibiting unwanted polymerization of reactive monomers within a liquid. The method comprises the combined usage of a quinone methide with a quinone diimide to the liquid monomer. This combination has an unexpected synergistic effect. Thus, in some ratios, the combination results in practically 100% inhibition.

The invention discloses water-soluble triterpenephenol compounds having antitumor activity represented by formula (I), wherein the substituents R1˜R4 and M are defined as in the description. The invention also discloses a method for preparing the compounds of formula (I) used quinone methide triterpene compounds as starting materials. The water-soluble triterpenephenol compounds disclosed in the invention can be made into various dosage forms including injection, tablet, capsule, granule and liniment, particularly suitable for making into injection.

Methods and compositions are provided for inhibiting the polymerization of a vinyl aromatic monomer, such as styrene monomer, during elevated temperature processing thereof or during storage or shipment of polymer containing product. The compositions comprise a combination of a quinone methide derivative A) and a phenol compound B). The methods comprise adding from about 1-10,000 ppm of the combination to the monomer containing medium, per one million parts of the monomer.

Methods are provided for synthesis of abscisic acid and 8′ analogues thereof (including an enantiopure 8′-acetylene analogue) including methods wherein the previously reported first step of oxidation of 2,6-dimethylphenol (VI) to 2,6-dimethylbenzoquinone, mono ketal (VII) is replaced by a novel two step process comprising (i) oxidation of 2,6-dimethylphenol (VI) using potassium peroxymonosulfate with a catalytic amount of iodobenzene to produce 2,6-dimethylbenzoquinone (XVI) and (ii) ketalization of 2,6-dimethylbenzoquinone (XVI) using ethylene glycol, trimethylorthoformate with a catalytic amount of p-toluenesulfonic acid to produce 2,6-dimethylbenzoquinone, mono ketal (VII).

The invention provides a composition of matter and a method of its use in preventing unwanted polymerization reactions. The composition comprises an inhibitor and a retarder. The inhibitor is highly effective. The retarder is reliable under extreme and emergency situations. The inhibitor can be an alkylhydroxylamine. The retarder can be a 7-cyano-quinone methide. The combination of the inhibitor and retarder has been found to be far more effective than expected.