Synthetic resins or natural rubbers -- part of the class 520 ser – Synthetic resins – Processes of preparing a desired or intentional composition...
Reexamination Certificate
1998-02-06
2001-01-30
Reddick, Judy M. (Department: 1713)
Synthetic resins or natural rubbers -- part of the class 520 ser
Synthetic resins
Processes of preparing a desired or intentional composition...
C524S109000, C524S110000, C524S117000, C524S118000, C524S119000, C524S128000, C558S078000
Reexamination Certificate
active
06180700
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to diphosphites, and more particularly relates to neoalkyl diphosphites.
2. Description of the Related Art
Diphosphites of the formula:
wherein Y is a divalent radical selected from the group consisting of:
R is independently selected from the group consisting of hydrogen, alkyl of 1 to 6 carbon atoms, preferably of 1 to 4 carbon atoms, and halogen, preferably chlorine or bormine; R
1
is independently selected from the group consisting of hydrogen, alkyl of 1 to 12 carbon atoms, preferably from 1 to 6 carbon atoms, R
2
is independently selected from the group consisting of hydrogen, alkyl of 1 to 12 carbon atoms, preferably of 1 to 9 carbon atoms, and halogen, preferably chlorine or bromine; and R
3
is independently selected from the group consisting of alkyl of 1 to 12 carbon atoms, preferably of 1 to 9 carbon atoms, and halogen, preferably chlorine or bromine, see Dever et al. U.S. Pat. No. 3,467,733 which is incorporated herein by reference. Dever et al. teaches that the diphosphites may be obtained by reacting a cyclic phosphorohalidite of the formula:
wherein R is as previously mentioned, and A is halogen, preferably chlorine or bromine, and lists 5-butyl-5-ethyl-2-chloro-1,3,2,-dioxaphosphorinane, with a hydroxy organic compound of the formula:
wherein R
1
, R
2
, and R
3
are as previously mentioned, and lists 2,2-bis(4-hydroxyphenyl) propane among others. While some of these phosphites find utility as stabilizers for polymers, it is desired to improve their hydrolytic and ultraviolet light stability.
Consequently, the present invention provides a diphosphite exhibiting improved stability.
SUMMARY OF THE INVENTION
The present invention provides a phosphite of the formula:
wherein R
4
, R
5
, R
6
and R
7
are as defined below. The diphosphites are useful as stabilizers for organic materials such as thermoplastic polymers and exhibit improved hydrolytic and ultraviolet stability.
DETAILED DESCRIPTION OF THE INVENTION
The diphosphites are represented by the formula:
wherein each R
4
is independently selected from the group consisting of hydrogen and alkyl radicals of 1 to 6 carbon atoms, preferably of 1 to 4 carbon atoms more preferably hydrogen or t-butyl, and optionally halogen, preferably chlorine or bromine, each R
5
is an alkyl group, preferably having from 1 to 6 carbon atoms, each R
6
is independently selected from the group consisting of alkyl radicals of 1 to 6 carbon atoms. R
7
is a divalent radical, and is preferably a divalent alkylidene having from 1 to 6 carbon atoms such as isopropylidene. Optionally R
7
may be a direct bond, or R
7
may be a sulphur group or an oxygen group or an organo siloxane group.
The diphosphites may be obtained from the following reactants: a) phosphorous trichloride (PCl
3
) or a phosphite ester (POR)
3
wherein each R
8
is a hydrocarbon radical preferably selected from the group consisting of alkyl and aryl groups, b) neoalkylene glycols, and c) the hydroxy organic compound is tetra alkyl hindered bisphenolic like 2,2-bis(4-hydroxy-3,5-di-t-butyl phenyl) propane. The neoalkylene glycol may be reacted with the phosphorous trichloride to form a phosphorohalidite which can then be reacted with the tetra alkyl hindered bisphenolic such as (2,2-bis(4-hydroxy-3,5-t-butyl phenyl) propane) to yield the desired diphosphite.
A nitrogen-containing compound or acid acceptor may be utilized to neutralize the reaction product, there may be utilized triethylamine, tributylamine, tripropylamine, pyridine, dimethylamine, and the like. If desired, a hydrocarbon solvent may be utilized.
The reaction between the cyclic phosphorohalidite and hydroxy organo compound may be effected by mixing the reactants together at room temperature, or, if necessary, by heating the mixture of reactants to moderately elevated temperatures. The reaction can be carried out most conveniently at atmospheric pressures. However, if preferred, pressures either higher or lower than atmospheric may be employed.
relative amounts of the reactants employed are not critical, although it is desirable that an excess of hydroxy compound be avoided. It is preferred that the cyclic phosphorohalidite and hydroxy organic compound be present in the reaction zone in about stoichiometric proportions.
When a molar porportion of dihydroxy organic compound is reacted, substantially two molar proportions of cyclic phosphorohalidite are employed, however, an excess of up to five or more molar proportions may also be utilized. The nitrogen-containing acid acceptor is added to the reaction product in substantially molar porportions based upon the quantity of cyclic phosphorohalidite utilized. However, it is within the scope of the invention to employ an excess of nitrogen-containing acid acceptor.
In conducting the reaction, the total amount of cyclic phosphorochloridite and hydroxy organic compound may be charged to a reaction vessel initially. The reaction times may vary, but generally time in the range of one to eight hours is sufficient to complete the reaction. Following this initial reaction, the nitrogen-containing acid acceptor may be introduced to the reaction vessel in any suitable manner. The introduction of nitrogen-containing compound is generally completed in times ranging from one to six hours.
The reaction mixture can be worked up in any suitable manner. It is possible, for instance, to remove the solid constituents by filtration. If a solvent is employed in the reaction, it may be removed by distillation, evaporation or by any other suitable method. Because of the high yields which are in many cases obtainable, separation of the desired cyclic diphosphite, following filtration and solvent removal, is not always required for utility of the product and in such cases may be dispensed with. However, if separation is desired, techniques such as distillation, extraction, crystallization, or the like, may be employed.
The diphosphites are useful as stabilizers for polymeric materials including polypropylene, polyethylene, polycarbonate, polyethylene terephthete, polybutylene terephthalate, polyphenylene ethers, polystyrene, acrylonitrile-butadiene-styrene, EPDM rubber, polyurethanes and polyamides. Optionally, the material is a polypropylene, which may contain a residual catalyst such as titanium catalyst on a magnesium halide carrier. The phosphite is preferably present in the polymeric composition at a level of from 0.01 percent by weight to 1 percent by weight based on the total weight of the composition.
Thermoplastic compositions containing a polymer and an amount of the present phosphite can be made by blending. The phosphites of this invention are effective antioxidants which may be employed in a wide range of organic polymers. Polymers which can be stabilized include:
1. Polymers which are derived from mono- or diolefins, e.g., polyethylene which can optionally be crosslinked, polypropylene, polyisobutylene, polymethylbutene-1, polymethylpentene-1, polyisoprene, polybutadiene.
2. Mixtures of the homopolymers cited under (1), for example mixtures of polyporpylene and polyethylene, polypropylene and polybutene-1, polypropylene and polyisobutylene.
3. Copolymers of the monomers based on the homopolymers cited under (1), for example ethylene/propylene copolymers, propylene/butene-1 copolymers, propylene/isobutylene copolymers, ethylene/butene-1 copolymers as well as terpolymers of ethylene and propylene with a diene, for example hexadiene, dicyclopentadiene or ethylidene norbornene, and copolymers of &agr;-olefins, e.g., ethylene, with acrylic or methacrylic acid.
4. Polystyrene.
5. Copolymers of styrene and of &agr;-methylstyrene, for example styrene/butadiene copolymers, styrene/acrylonitrile copolymers, styrene/acrylonitrile/methylacrylate copolymers, styrene/acrylonitrile/acrylic ester copolymers, styrene/acrylonitrile copolymers modified with acrylic ester polymers to provide impact strength as well as block copolymers, e.g., styrene/butadiene/stryene block copolymers.
6. Graft copolymers
General Electric Company
Reddick Judy M.
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