Compositions – Compositions containing a single chemical reactant or plural... – Organic reactant
Reexamination Certificate
2002-02-04
2004-07-13
Toomer, Cephia D. (Department: 1714)
Compositions
Compositions containing a single chemical reactant or plural...
Organic reactant
C252S404000, C252S405000, C252S406000, C585S004000, C524S186000
Reexamination Certificate
active
06761833
ABSTRACT:
FIELD OF THE INVENTION
This invention relates to compositions for stabilization of vinyl monomers; the compositions include(A) at least one alkyl hydroxyl amine compound and at least one sulfide compound, or (B) at least two alkyl hydroxyl amine compounds and at least one phenolic compound.
BACKGROUND OF THE INVENTION
During the manufacture, storage, and transportation of vinyl monomers, undesired polymers or organic peroxides are often formed.
During manufacture, undesired polymers or organic peroxides foul the processing equipment which cause reduced heat transfer and increased downtime cleaning.
During storage and transportation, these unwanted polymers or organic peroxides not only affect the product quality but also present an explosion hazard. Butadiene, for example, forms butadiene peroxide in contact with oxygen which can lead to uncontrolled polymerization.
Currently, various phenolic compounds are used to stabilize vinyl monomers, but they are toxic, expensive, and not effective inhibiting popcorns in vapor phase. For certain applications, these phenolic stabilizers require the presence of oxygen for proper functioning as in the case of styrene stabilization using 4-tert-butylcatechol (TBC).
Also, the prior art discloses the use of individual dialkylhydroxylamines and alkylhydroxylamine-based composites as stabilizers for vinyl monomers.
Synergistic effects have been claimed for composite stabilizers of alkylhydroxylamines with water-soluble amines, trialkylamine oxides, phenylenediamines, oximes, alkyl benzene sulfonic acids, dinitrophenols, TBC, and benzoquinone deriatives. However, the previously disclosed composites either focus on two-component stabilizing systems or are limited to only one type of vinyl monomers under restricted conditions.
Examples of the prior art follow.
Mayer-Mader, R.; Hohmann, G; U.S. Pat. No. 3,878,181; 1975; (Bayer Aktiengesellschaft) discloses a process for terminating emulsion polymerization of chloroprene and/or 2,3-dichlorobutadiene using a mixture of DEHA and a water-soluble amine (such as triethanolamine).
Miller, R. F.; U.S. Pat. No. 4,409,408; 1983; (Atlantic Richfield Company) discloses a mixture of N,N-diakylhydroxylamine and teriary alkylcatechol for stabilizing vinyl aromatic monomers. Specific claims are made for the synergistic effect of a DEHA/TBC mixture in stabilizing styrene or alkyl substituted styrene.
Link, J.; Miller, R. F.; CA Patent 1,227,449; 1987; (Atlantic Richfield Company) discloses a method of using lower dialkylhydroxylamines to inhibit polymerization of hydrocarbons during their processing. Specific claims are made for butadiene where DEHA and a blend of DEHA and DEHA exhibited high performance.
Miller, R. F.; U.S. Pat. No. 4,654,450; 1987; (Atlantic Richfield Company) describes the use of a mixture of a N,N-dialkylhydroxylamine and an alkyl benzene sulfonic acid to stabilize vinyl aromatic compounds. Specific claims are made for DEHA-based composite stabilizer.
Martin, J. F.; U.S. Pat. No. 4,720,566; 1988; (Betz Laboratories, Inc.) describes the use of a mixture of a hydroxylamine and a phenylenediamine compound to inhibit polymerization of acrylonitrile, particularly in a quench column.
Sato, K.; Nishii, K.; Ito, H.; JP Patent # 63,223,003; 1988 (Tokai Electro-Chemical Co., Ltd.) discloses the use of a mixture of trialkylamine oxides and N,N-diakylhydroxylamines to inhibit popcorn formation in an olefin recovery or purification system.
Nakajima, S.; JP Patent # 01,013,041; 1989; (Hakuto Chemical Co., Ltd.) describes a composition for inhibiting popcorn formation in olefin production apparatus. The disclosed composition comprises compounds selected from hydroxylamines, oximes, mercaptans, etc., and optionally antioxidants and surfactants.
Nakajima, S.; U.S. Pat. No. 4,956,020; 1990; (Hakuto Chemical Co., Ltd.) discloses an inhibitor for preventing popcorn polymer growth on the inner surface of an olefin production unit. Such an inhibitor comprises at least one compound selected from a group that include phenylenediamine, hydroxylamine, etc. The inhibitor is applied to the inner surface when the operation of the production apparatus is suspended.
Wright, B. E.; Weaver, C. E.; Reid, D. K.; U.S. Pat. No. 5,282,957; 1994; (Betz Laboratories, Inc.) claims a method of using a hydroxyakylhydroxylamine compound to inhibit polymerization of hydrocarbons during their processing and storage.
Arhancet, G. B.; Henrici, I. K.; U.S. Pat. No. 5,396,004; 1995; (Betz Laboratories, Inc.) discloses a mixture of phenylenediamine and a hydroxylamine compound for inhibiting polymerization of vinyl aromatic monomers under distillation conditions.
Arhancet, G. B.; U.S. Pat. No. 5,426,257; 1995; (Betz Laboratories, Inc.) discloses the use of a hydroxylamine-based composition for inhibiting polymerization of vinyl aromatic monomers in the absence of oxygen. Such a composition is either a mixture of an oxime and a hydroxylamine compound, or a mixture of an oxime, a hydroxylamine, and a phenylenediamine compound.
Arhancet, G. B.; U.S. Pat. No. 5,446,220; 1995; (Betz Laboratories, Inc.) discloses the use of a hydroxylamine-based ternary composition for inhibiting polymerization of vinyl aromatic monomers in oxygen-free processing systems. Such a composition comprises a dinitrophenol, a hydroxylamine, and a phenylenediamine compound. The preferred hydroxylamine compound is claimed to be bishydroxypropylhydroxylamine.
Arhancet, G. B.; Henrici, I. K.; U.S. Pat. No. 5,510,547; 1996; (Betz Laboratories, Inc.) discloses the use of a mixture of a hydroxylamine and a phenylenediamine compound to inhibit polymerization of vinyl aromatic monomers in oxygen-free processing systems. Specifically claimed hydroxylamines are DEHA and isopropylhydroxylamine(NiPHA).
Arhancet, G. B.; Henrici, I. K.; WO Patent # 9,641,783; 1996; (Betz Laboratories, Inc.) discloses a method of inhibiting polymerization of vinyl aromatic monomers using a mixture of a hydroxylamine compound and a benzoquinone derivative. The preferred hydroxylamine in such a composition is bis(hydroxypropyl)hydroxylamine.
Arhancet, G. B.; Henrici, I. K.; Martin, J. F.; WO Patent # 9,638,399; 1996; (Betz Laboratories, Inc.) describes the use of a mixture of hydroxylamine compound and a dinitrosalicylic acid derivative to inhibit polymerization of vinyl aromatic monomers during processing. The preferred hydroxylamine in such a composition is bis(hydroxypropyl)hydroxylamine.
Arhancet, G. B.; Henrici, I. K.; WO Patent # 9,735,821; 1997; (BetzDearborn Inc.) discloses a composition for inhibiting polymerization of vinyl aromatic monomers in the absence of oxygen. Such a composition comprises a hydroxylamine and a phenylenediamine compound. Specifically claimed hydroxylamines are DEHA, NiPHA, and bis(hydroxypropyl)hydroxylamine.
Ukita, K.; Onodera, Y.; Futamura, S.; JP Patent # 10,251,663; 1998; (Nippon Zeon Co., Ltd.) discloses a method of preventing polymerization in an extractive distillation process for isoprene separation. In such a method, a di-lower-alkylhydroxylamine (e.g., DEHA) is added to the distillation column above the feeding point of the extraction solvent.
Arhancet, G. B.; Bringol, E. H.; WO Patent # 9,802,403; 1998; (BetzDearborn Inc.) provides a method of using a combination of a phenol and a hydroxylamine compound to inhibit polymerization of vinyl aromatic monomers in reactor effluent condenser and vent gas compressor systems. The most preferred hydroxylamine claimed is DEHA.
The objective of the present invention to develop improved stabilizing compositions compared to conventional phenolic stabilizers and alkylhydrooxyyl amine compositions.
SUMMARY OF THE INVENTION
The present invention relates to the synergistic behavior involving certain combinations of dialkylhydroxylamines with phenolic and sulfide compounds.
Compositions of the present invention are blends of alkylhydroxylamines with either phenolic compounds or sulfide compounds which are synergistic and superior to individual dialkylhydroxylamines and conventional stabilizers (such as TB
Lou Jianfeng
Nosowitz Martin
Atofina Chemicals, Inc.
Rudman Gilbert W.
Toomer Cephia D.
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