Fuel and related compositions – Candle composition
Reexamination Certificate
2001-04-02
2003-04-15
Toomer, Cephia D. (Department: 1714)
Fuel and related compositions
Candle composition
C544S001000, C544S063000, C544S224000, C548S100000, C548S146000, C548S215000, C548S240000, C548S400000, C548S517000, C548S525000, C549S456000, C564S300000
Reexamination Certificate
active
06547841
ABSTRACT:
This invention pertains to the novel process for preparing sterically hindered N-substituted alkoxyamines by the transition-metal-catalyzed decomposition of a diazonium salt in the present of a sterically hindered nitroxyl radical.
BACKGROUND OF THE INVENTION
N-Aryloxyamines have been prepared in the prior art by the reaction of a phenylhydrazine with a stable nitroxide. In certain instances, N-aryloxyamines have been prepared in low yield by the decomposition of aryldiazonium salts in the presence of a nitroxyl radical, but without a transition metal catalyst being present. These papers are often about mechanistic studies with poor yields and state that the reaction described is limited in scope. A. C. Scott et al., J. Chem. Soc., Perkin Trans. 2, 1980, 260-266.
In another study, an aryl radical formed from a diazonium salt added intramolecularly to a double bond and the result alkyl radical was trapped by a stable nitroxyl radical. A. L. J. Beckwith and G. F. Meijs, J. Chem. Soc., Chem. Commun. 1981, 595-597.
It is clear that the instant process is a facile and direct way to prepare these interesting and useful instant stabilizer compounds in yields far exceeding anything found in the related prior art. Additionally, the prior art processes often use the nitroxide component as a solvent, i.e. in large excess, in contrast to the instant process.
In respect to wax stabilization, the use of selected hindered amines and/or benzotriazole UV absorbers is known in the prior art. This is seen in Japanese Hei 3-278554; WO 00/22037; and U.S. Pat. Nos. 3,530,084; 4,379,721; 4,616,051 and 5,964,905 and copending applications Ser. Nos. 09/495,495, 09/495,496 and 09/741,583.
DETAILED DISCLOSURE
The instant invention pertains to a process for preparing a sterically hindered N-alkoxyamine of formula I,
II or III
which comprises
reacting a sterically hindered nitroxyl compound of formula IV, V or VI
with a diazonium salt of an aromatic amine of formula VII
in the presence of a transition-metal catalyst
wherein
X is —CH
2
—, —O—, —S— or —NR
8
— where R
8
is hydrogen or alkyl of 1 to 12 carbon atoms,
R
6
and R
7
are independently alkyl of 1 to 8 carbon atoms, or R
6
and R
7
together are tetramethylene or pentamethylene,
R is hydrogen, alkyl of 1 to 18 carbon atoms, aralkyl of 7 to 15 carbon atoms, aryl of 6 to 10 carbon atoms, hydroxyl, carboxyl, amino, alkylamino of 1 to 18 carbon atoms, dialkylamino of 2 to 36 carbon atoms, oxo, alkylthio of 1 to 18 carbon atoms, alkoxy of 1 to 18 carbon atoms, aryloxy of 7 to 15 carbon atoms, alkylcarbonyloxy of 2 to 18 carbon atoms or alkylcarbonylamino of 2 to 18 carbon atoms,
G
1
to G
4
are independently hydrogen, halogen, nitro, cyano, alkyl of 1 to 18 carbon atoms, aralkyl of 7 to 15 carbon atoms, aryl of 6 to 10 carbon atoms, hydroxyl, carboxyl, alkylthio of 1 to 18 carbon atoms, alkoxy of 1 to 18 carbon atoms, aryloxy of 7 to 15 carbon atoms, alkylcarbonyloxy of 1 to 18 carbon atoms, alkylsulfonyl of 1 to 18 carbon atoms, arylsulfonyl of 6 to 15 carbon atoms, sulfo or phosphono, or any two vicinal substituents connected together to form a mono or polycyclic ring, so that formula VII can represent inter alia 1-naphthylamine or 2-naphthylamine.
G
5
to G
9
are independently hydrogen, alkyl of 1 to 18 carbon atoms, aralkyl of 7 to 15 carbon atoms or aryl of 6 to 10 carbon atoms,
In another embodiment of the instant invention, any one of G
1
to G
9
is phenyl.
The diazonium salt of the aromatic amine of formula VII can be prepared by reaction with an alkyl nitrite ester, such as tert-butyl nitrite. The diazonium salt can also be prepared using a nitrite salt and an acid, such as sodium nitrite and hydrochloric acid.
Indeed, the instant compounds can be made directly from nitroxides which are commercially available such as TEMPO (1-oxyl-2,2,6,6-tetramethylpiperidine), 4-OXOTEMPO (1-oxyl-2,2,6,6-tetramethyl-4-oxopiperidine) and di-tert-butyl nitroxide.
The reaction is conveniently carried out in chlorobenzene as solvent at a temperature of 0 to 100° C., or between 20 and 70° C.
The transition metal is a metal of Group 4, 5, 6, 7, 8, 9 or 10 of the periodic table; such as copper(I), copper(II), cobalt(II), manganese(II) or gold(I).
The process is carried out in the presence of 0.05 mole % to stoichiometric quantities of the transition metal catalyst.
The transition metal catalyst is, for example, ligated by a salcoamine ligand such as (S,S)-(+)-N,N-bis(3,5-di-test-butylsalicylidene)-1,2-cyclohexanediaminocobalt(II) or N,N-bis(salicylidene)ethylenediaminocobalt(II).
In one embodiment, X is methylene.
In another embodiment, R is hydrogen, hydroxyl, oxo or acetamido.
In still another embodiment, R
6
and R
7
are each methyl.
A further aspect of this invention is the addition of pyridine to the reaction mixture either as a component of the reaction mixture or as the solvent in the presence of the transition metal catalyst. Pyridine has been found to increase further the yield of the reaction as well as having superior solvent properties in certain cases. For example, when the diazonium salt is made using sodium nitrite and hydrochloric acid, pyridine also serves as a basic medium for neutralizing excess acid.
The stabilization of diazonium salts by pyridine has been reported by Heinrich Zollinger et al. (Helv. Chimica Acta, 59, 1438 (1976). Furthermore it is stated that pyridine promotes a homolytic radical pathway. Without a transition metal catalyst, however, the homolytic cleavage at 70° C. is slow and is not useful.
The instant invention also pertains to a composition stabilized which comprises
(a) an organic material subject to degradation by heat, light or oxygen, and
(b) an effective stabilizing amount of a compound of formula I, II or III as described above.
Preferably, the organic material is a natural, semi-synthetic or synthetic polymer, especially a thermoplastic polymer.
Most preferably, the polymer is a polyolefin or polycarbonate, especially polyethylene or polypropylene; most especially polypropylene; or the polymer is a styrenic, ABS, a nylon, a polyester such as poly(ethylene terephthalate) or poly(butylene terephthalate), a polyurethane, an acrylate, a rubber modified styrenic, poly(vinyl chloride), poly(vinyl butyral), polyacetal (polyoxymethylene), poly(ethylene naphthalene-dicarboxylate), or other blends or copolymers such as poly(ethylene/1,4-cyclohexylene-dimethylene terephthalate) PETG or an ionomer as described on page 29.
In another preferred embodiment of the instant invention, the organic material is a resin selected from the group consisting of a thermoset acrylic melamine resin, an acrylic urethane resin, an epoxy carboxy resin, a silane modified acrylic melamine, an acrylic resin with carbamate pendant groups crosslinked with melamine or an acrylic polyol resin crosslinked with melamine containing carbamate groups.
Most preferably, the resin is a thermoset acrylic melamine resin or an acrylic urethane resin.
In yet another preferred embodiment of the instant invention, the organic material is a recording material.
The recording materials according to the invention are suitable for pressure-sensitive copying systems, photocopying systems using microcapsules, heat-sensitive copying systems, photographic materials and ink jet printing.
The recording materials according to the invention are distinguished by an unexpected improvement in quality, especially with regard to the fastness to light.
The recording materials according to the invention have the construction known for the particular use. They consist of a customary carrier, for example, paper or plastic film, which has been coated with one or more layers. Depending on the type of material, these layers contain the appropriate necessary components, in the case of photographic materials, for example, silver halide emulsions, dye couplers, dyes and the like. Material particularly suitable for ink jet printing has a layer particularly absorptive for ink on a customary carrier. Uncoated paper can also be employed for ink jet printing. In this case the paper acts
Pastor Stephen D.
Shum Sai Ping
Ciba Specialty Chemicals Corporation
Hall Luther A. R.
Stevenson Tyler A.
Toomer Cephia D.
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