Mineral oils: processes and products – Chemical conversion of hydrocarbons – With prevention or removal of deleterious carbon...
Reexamination Certificate
2002-01-16
2004-02-03
Griffin, Walter D. (Department: 1764)
Mineral oils: processes and products
Chemical conversion of hydrocarbons
With prevention or removal of deleterious carbon...
C585S950000, C203S008000
Reexamination Certificate
active
06685823
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention is directed to the use of at least one C-nitrosoaniline compound and/or quinone imine oxime, alone or in combination with at least one stable nitroxide free radical compound, and/or at least one nitroaromatic compound, and/or at least one quinone alkide compound, preferably a quinone methide, and/or at least one quinone compound, and/or at least one hydroquinone compound, and/or at least one hydroxylamine compound, and/or at least one phenylenediamine compound, and/or air or oxygen to inhibit the polymerization of ethylenically unsaturated monomers.
2. Description of Related Art
Many ethylenically unsaturated monomers undesirably polymerize at various stages of their manufacture, processing, handling, storage, and use. A particularly troublesome problem is equipment fouling caused by polymerization in the purification stages of the production processes of such monomers. Polymerization, such as thermal polymerization, during their purification results in the loss of the monomer and a loss in production efficiency owing to the deposition of polymer in or on the equipment being used in the purification, the deposits of which must be removed from time to lime. Additionally, the formation of soluble polymer leads to loss of monomer, i.e., a lower yield, and an increase in the viscosity of any tars that may be produced. The processing of the tars then requires higher temperature and work (energy cost) to remove residual monomer.
A wide variety of compounds has been proposed and used for inhibiting uncontrolled and undesired polymerization of ethylenically unsaturated monomers. There remains a need, however, for an inhibitor that not only provides highly effective inhibition of polymerization during normal operation of a continuous manufacturing or purification process, but also provides satisfactory protection in the event of a loss of continuous inhibitor feed. While many inhibitors are known to provide sufficient protection in one of these scenarios, they have not been fully satisfactory under both normal and upset operating conditions. Accordingly, a substantial need continues in the art for improved compositions for inhibiting the polymerization of such monomers during their production and during the distillation process for purifying or separating them from impurities, as well as during transport and storage.
Aromatic nitroso and di-nitroso compounds are known to be useful as chemical agents capable of promoting the formation of filler-elastomer linkages. The aromatic nitroso compounds may be aromatic amines, including polyamines or phenolic compounds. They are also known to be useful intermediates in the production of other chemicals, such as p-aminodiphenylamine.
U.S. Pat. Nos. 3,988,212 and 4,341,600 disclose the use of N-nitrosodiphenylamine combined with dinitro-cresol derivatives for inhibiting the polymerization of vinyl aromatic compounds under vacuum distillation conditions.
U.S. Pat. No. 4,362,893 discloses that C-nitrosodiarylamines may be prepared in a single stage from diarylamines by adding alcoholic solutions of a hydrogen halide below the surface of a stirred mixture of the diphenylamine in an organic liquid containing water.
U.S. Pat. No. 4,479,008 discloses a process for preparing p-nitrosodiphenylamine hydrochloride from N-nitrosodiphenylamine and hydrogen chloride. The product is prepared in the absence of an aromatic solvent and using a solvent consisting essentially of aliphatic C
5
-C
10
alcohol.
U.S. Pat. No. 4,518,803 discloses a process for the preparation of p-nitrosodiphenylamine hydrochloride comprising reacting diphenylamine, C
5
-C
10
alkyl nitrite and anhydrous HCl in the presence of a C
5
-C
10
aliphatic alcohol and essentially in the absence of an aromatic solvent.
U.S. Pat. No. 5,001,171 discloses that uncured modified rubber compositions comprising mixtures of elastomers and a reinforcing filler can be prepared by a process which comprises, inter alia, the use of at least one chemical agent capable of promoting the formation of filler-elastomer linkages. Examples of such useful chemical agents include aromatic furazan oxides, heterocyclic di-N-oxides, 1-hydroxy-benzimidazole-3-oxide compounds, 1,3-dihydroxy-benzimidazolinone compounds, and aromatic nitroso compounds.
U.S. Pat. No. 5,623,088 discloses a method of producing 4-aminodiphenylamine (4-ADPA) wherein aniline or substituted aniline derivatives and nitrobenzene are reacted under suitable conditions to produce 4-nitrodiphenylamine or substituted derivatives thereof and/or their salts, either or both of which are subsequently reduced to produce 4-ADPA or substituted derivatives thereof. The 4-ADPA or substituted derivatives thereof can be reductively alkylated to produce p-phenylenediamine products or substituted derivatives thereof which are useful as antiozonants. A second embodiment of the invention is the tetrasubstituted ammonium salts or alkyl substituted diammonium salts of 4-nitrodiphenylamine, 4-nitrosodiphenylamine and the substituted derivatives thereof wherein each substituent of the tetrasubstituted ammonium ion is independently selected from the group consisting of alkyl, aryl and arylalkyl groups and each alkyl substituent of the alkyl substituted diammonium salt is independently selected.
U.S. Pat. No. 5,648,543 discloses a process for producing a 4-nitrosodiphenylamine of the formula
wherein R
1
and R
2
independently represent hydrogen atom, methyl group, ethyl group, cyclohexyl group, methoxy group, ethoxy group or chlorine or bromine atom, or a salt thereof, comprising treating a diphenylamine represented by the formula
wherein R
1
and R
2
are as defined above with (i) a mixture of nitrogen oxides, (ii) a hydrogen halide and (iii) an aliphatic alcohol, wherein the atomic ratio of oxygen to nitrogen of the mixture of nitrogen oxides is more than 1.0 and less than 2.0.
U.S. Pat. No. 5,739,403 discloses the production of 4-aminodiphenylamines by reacting optionally substituted aniline with optionally substituted nitrobenzene in the presence of water and/or alcohols and organic and/or inorganic bases and then catalytically hydrogenating the resultant nitro- and/or nitrosodiphenylamine in the presence of water. The catalytic hydrogenation of the reaction mixture is performed in the presence of 25 to 80 weight percent of water, relative to the weight of the reaction mixture from the condensation reaction, the hydrogenation catalyst is removed from the hydrogenation mixture once absorption of hydrogen has ceased, 10 to 100 vol. percent of aromatic solvent, relative to the total volume of the hydrogenation mixture, is optionally added to the hydrogenation mixture, the resultant organic phase is separated in order to isolate the 4-aminodiphenylamine and the aqueous phase is returned to the initial reaction mixture.
Quinone methides, quinones, hydroquinones, bydroxylamines, and nitroxyl compounds are known polymerization inhibitors.
Quinone methides act mainly as retarders, giving a significant amount of polymer during normal inhibition usage but providing protection in the event of a plant upset during monomer purification by slowing the rate of polymer formation under static conditions. Because of the poor normal inhibition performance, quinone methides must be used in fairly high dosages, making them not very economical to use.
U.S. Pat. Nos. 4,003,800 and 4,040,911 disclose the use of quinone alkides in a styrene purification process.
The following patents, assigned to Ciba-Geigy Corporation or Ciba Specialty Chemicals Corporation, relate to quinone methides and uses thereof.
U.S. Pat. Nos. 5,583,247, 5,670,692, and 5,750,765 disclose the protection of ethylenically unsaturated monomers from premature polymerization during manufacture and storage by the incorporation therein of an effective stabilizing amount of a quinone methide compound having an electron withdrawing substituent at the 7-methylene group.
U.S. Pat. No. 5,616,774 discloses the protection of ethylenically unsaturated monomer
Abruscato Gerald J.
Benage Brigitte
Eisenstein Andrew J.
Dilworth Michael P.
Griffin Walter D.
Uniroyal Chemical Company, Inc.
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