Compositions – Oxidative bleachant – oxidant containing – or generative – Composition containing a stabilizer or a product in the form...
Reexamination Certificate
2001-05-29
2002-03-19
Anthony, Joseph D. (Department: 1714)
Compositions
Oxidative bleachant, oxidant containing, or generative
Composition containing a stabilizer or a product in the form...
C252S186420, C252S182130, C252S182230, C252S182290, C526S227000, C526S228000, C525S256000, C525S387000
Reexamination Certificate
active
06358435
ABSTRACT:
The present invention relates to a composition comprising cyclic ketone peroxide and phlegmatizer. It also pertains to the use of such a composition in (co)polymerization and polymer modification processes.
Numerous peroxides are known that need to be phlegmatized with an inert diluent or solvent in order to permit their safe handling and use. Cyclic ketone peroxides form no exception. In the context of the present invention, these diluents and solvents are also referred to as phlegmatizers. A phlegmatizer can be a single compound or a mixture of compounds. Cyclic ketone peroxides are useful in, for example, radical (co)polymerization and polymer modification processes. Cyclic ketone peroxides have dimeric, trimeric, tetrameric or higher oligomeric structures.
Conventional cyclic ketone peroxides which meet all safety regulations and can be stored, shipped, and handled in an acceptable, safe fashion have a low content of active oxygen. However, such formulations with low peroxide contents are undesirable, since their use in polymerization and/or polymer modification processes will lead to high levels of undesired inert diluent or solvent residues in the resulting polymeric product and will add to the costs of transport and manufacturing.
Applicant's earlier patent application WO 98/33770 discloses formulations of peroxides in a mixture of at least two phlegmatizers that have boiling points more than 20° C. apart. In Examples 1-3 of WO 98/33770, formulations of cyclic methyl ethyl ketone peroxide in mixtures of Primol® 352 (95% boil-off point 477° C.) and isododecane (boiling point, i.e. bp, 185° C.) are described which have an active oxygen content of 6 weight percent. Cyclic ketone peroxide formulations having a higher active oxygen content are not disclosed or suggested therein.
Whereas the cyclic ketone peroxide formulations of WO 98/33770 have acceptable safety properties, the active oxygen content is still relatively low. Furthermore, the use of two different phlegmatizers is unattractive with respect to handling and the required registration of dual phlegmatizer compositions. Another disadvantage is that the use of low-boiling phlegmatizers is undesired in many applications in respect of the volatile organic compound content in the end product.
In Comparative Examples A and B of WO 98/33770 it is shown that the single phlegmatizer cyclic ketone peroxide formulations in either Primol® 352 or isododecane are not safe. Moreover, the active oxygen content of 6 weight percent is undesirably low. Thus, there remains a need in the art for new cyclic ketone peroxide formulations.
Incidentally, formulations of cyclic ketone peroxides in a single phlegmatizer are further known from applicant's earlier patent application WO 96/03397. This document discloses formulations of cyclic methyl ethyl ketone peroxides in isododecane, pentadecane (bp 270° C.), and Primol® 352. This document, however, does not relate to the problem addressed in the present application, i.e. cyclic ketone peroxide formulations which are safe and have a high active oxygen content. Furthermore, pentadecane is too expensive, isododecane is too volatile, and the use of Primol® 352 presents problems in handling due to the increased viscosity of formulations containing this latter phlegmatizer.
It is noted that WO 93/25615 discloses that a styrene oligomer can be used as phlegmatizer for organic peroxides. There is no disclosure or suggestion of how to use styrene oligomers to make cyclic-ketone peroxide compositions with a high active oxygen concentration.
It is also noted that FR 862974, published in 1941, discloses formulations of acetone peroxide and butanone, i.e. methyl ethyl ketone, peroxide in gas oil. FR 862974 does not relate to the technical problem of the instant application either. Moreover, formulations of cyclic ketone peroxides in petroleum fractions like gas oil are unattractive for use in polymerization and polymer modification processes in view of the fact that they contain aromatic compounds which will remain in the polymer end product upon use of such a formulation, causing adverse taste, smell, and colour. Furthermore, it will be difficult, if not impossible, to obtain the required approval for their use in food-grade polymer production.
It has unexpectedly been found that the use of phlegmatizers with a specific boiling point permits the formulation of safe cyclic ketone peroxide compositions having a high active oxygen content and meeting all of the other above-mentioned requirements at an economically attractive cost price.
The composition according to the present invention is characterized in that the phlegmatizer has a 95% boil-off point falling in the range of from 220 to 265° C.
In the instant application, by 95% boil-off point is meant the boiling point (bp) at which 95% by weight of the phlegmatizer is boiled off, or in the case of a single solvent compound, such as tetradecane, the boiling point of this compound. Typically the 95% boil-off point is obtained from conventional analytical methods like ASTM-D5399. For example, for mixtures of compounds obtained via fractional distillation of petroleum a 95% boil-off point is frequently reported in the product data sheet. Such mixtures are commercially available from various sources at a relatively low cost price. For example, lsopar® M having a boiling point range of 208-254° C. and a 95% boil-off point of 245° C. can be purchased from Exxon. Preferably, the 95% boil-off point lies in the range of from 220 to 260° C., more preferably from 225 to 255° C., most preferably from 235 to 250° C. Either a single phlegmatizer or a mixture of phlegmatizers can be used in the composition of the present invention, as long as the single phlegmatizer or the mixture of phlegmatizers fulfills the 95% boil-off point requirement of claim
1
. Preferably, a single phlegmatizer is used. If a mixture of phlegmatizers is used, the difference between the boiling points should be less than 20° C., with the median of a boiling point range being taken in the case of a phlegmatizer consisting of a mixture of compounds.
Examples of phlegmatizers which are suitable for use in the composition according to the present invention include linear and branched hydrocarbon solvents such as tetradecane, tridecane, Isopar® M, Exxsol® D80, Exxsol® D100, Exxsol® D100S, Soltrol® 145, Soltrol® 170, Varsol® 80, Varsol® 110, Shellsol® D100, Shellsol® D70, Halpasol® i 235/265, and mixtures thereof. Particularly preferred phlegmatizers are Isopar® M and Soltrol® 170. Although less preferred, it is also possible to use a specific fraction of the styrene oligomers of WO 93/25615.
Typically, the cyclic ketone peroxide composition according to the present invention is liquid at room temperature, with the peroxide completely dissolved in the phlegmatizer of choice.
The compositions of the present invention, unlike compositions of the same cyclic ketone peroxide with the same active oxygen content in which use is made of a phlegmatizer not satisfying the 95% boil-off point requirement as specified herein, are safe. In this specification, by “safe” is meant that the compositions of the present invention pass the following tests:
the Deflagration test (deflagration),
the Time Pressure test (deflagration),
the Koenen test (heating under defined confinement),
the Pressure Vessel test (heating under defined confinement), and
the Thermal Explosion Vessel test (heating under defined confinement).
Passing these tests means a “medium” or “low” rating in the heating under defined confinement tests and a “no” or “yes, slowly” rating in the deflagration tests. The final hazard rating, for which the most severe rating in any one of the tests is used, must be “medium” or “low.”
The safety tests and corresponding criteria are documented in the “United Nations Recommendations on the Transport of Dangerous Goods, Manual of Tests and Criteria,” as explained below in the section “Examples.”
Typically, the cyclic ketone peroxides that can be formulated in accordance with the present invention are r
De Groot Johannes Jacobus
DeVries Bernhard
Koelewijn Willem
Schuurman Pieter
Akzo Nobel N.V.
Anthony Joseph D.
Fennelly Richard P.
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