Organic compounds -- part of the class 532-570 series – Organic compounds – Phosphorus esters
Reexamination Certificate
2000-03-10
2002-03-26
Lambkin, Deborah C. (Department: 1626)
Organic compounds -- part of the class 532-570 series
Organic compounds
Phosphorus esters
C558S096000, C558S146000, C558S150000
Reexamination Certificate
active
06362358
ABSTRACT:
BACKGROUND OF THE INVENTION
The invention relates to a process for preparing phosphonite or phosphinites, in particular aromatic phosphonites or phosphinites, having significantly improved properties for stabilizing polymer materials. Products made by this process of the invention are distinguished by higher activity, improved hydrolysis stability and clear solubility as well as a markedly decreased content of unwanted byproducts.
FIELD OF THE INVENTION
As known to those skilled in the art, aromatic phosphonites or phosphinites may be prepared by Friedel-Crafts reaction (reaction 1) of aromatics with halogen-containing phosphorous compounds such as phosphorus trichloride, phosphorus tribromide resp. alkyl- or aryldihalophosphines. The aluminium halide adducts initially formed are cleaved by recomplexing with tertiary amines or phosphoryl chloride by methods known from the literature (reaction 1a). In a subsequent reaction (reaction 2) of the resultant aryldihalophosphines, alkylarylhalophosphines or diarylhalophosphines with alcohols or phenols in the presence or absence of inert solvents and/or acid-binding agents such as tertiary amines, for example, the desired phosphonites or phosphinites are obtained. In this case “halogen” is chloride or bromide, but preferably chloride. These reaction paths have long been known and are described in the literature (e.g. Michaelis, Ann., 293, 193 (1896); Kosolapoff, G. M., Organic Phosphorus Compounds, John Wiley & Sons, New York, 1972). The reaction diagrams below also explicitly include a multiplicity of reactions of types 1 and 2 on one aromatic substrate, e.g. the Friedel-Crafts reaction of diphenyl with 2 equivalents of phosphorus trichloride. The individual reaction partners can be used in this case in a deficiency, stoichiometrically or in excess amounts. Reactions of this type are described, for example, in GB Patent 1372528.
where independently of one another, each group
R is an aliphatic, cycloaliphatic or aromatic organic radical having 1-36 carbon atoms, which can also contain hetero atoms (N, O, P, S)
R′ is Hal or R;
R″ is an aliphatic, cycloaliphatic or aromatic organic radical having 1-36 carbon atoms, which can also contain hetero atoms (N, O, P, S);
R′″ is an aliphatic, cycloaliphatic or aromatic organic radical having 1-36 carbon atoms, which can also contain hetero atoms (N, O, P, S), or N(R′″)
3
as such is pyridine or alkyl-substituted pyridine;
Hal is Cl or Br
n is 0-5
m is equal to 1 if R′=R and m is equal to 2 if R′=Hal.
The said reaction mixtures may, under some circumstances, also further comprise organic or organophosphorus compounds such as phenols, alcohols, amines or phosphites, phosphonates, phosphates etc. which are likewise formed during the phosphonite/phosphinite synthesis, remain in the mixture as excess at the end of the reaction or else are deliberately added.
The reaction of Friedel-Crafts reaction products with alcohols or phenols to form phosphonites or phosphinites takes place either without solvent, in the presence of an inert non-polar solvent (such as aliphatics, cycloaliphatics or mixtures thereof) or alternatively without, with stoichiometric or superstoichiometric amounts of an acid acceptor (see reaction 2a).
Common to all these preparation processes is the fact that a certain proportion of unwanted byproducts is present, which byproducts result, for example, from the incomplete reaction of the halophosphorus compounds or are due to residual small amounts of aluminium halide or amine hydrohalide salts. According to the classical procedure, these must be removed by complex and cost-intensive purification processes, such as crystallization, distillation, filtration processes or membrane processes or ion exchange, if a pure product is to be obtained. If these byproduct salts remain in the product, its properties and the usability as polymer stabilizer may be impaired. Thus, the clear solubility, particularly in nonpolar solvents, or else the transparency of the polymers, is decreased, an increase in the corrosivity to metals, promoted by halide ions, can occur and unwanted decomposition processes, such as the hydrolysis of the compounds themselves or of hydrolysable polymers such as polyester or polycarbonate can also be promoted.
SUMMARY OF THE INVENTION
The object of the invention is to decrease significantly the content of unwanted byproducts in a simple and cost-effective manner and at the same time to increase the amount of active substance.
It has surprisingly been found that, after the preparation as described above of the reaction mixtures comprising phosphonites and/or phosphinites, the addition of a small amount of one or more protic compounds such as alcohols, ammonia, primary or secondary amines or water alone or, preferably, in combination with an oxide, hydroxide, (hydrogen)carbonate or (hydrogen)phosphate of a metal and subsequent simple separation of only a small amount of solids after a suitable reaction time leads to a significant decrease in the halide contents, an improvement in the clear solubility in nonpolar solvents, a decrease in the aluminium content and an improved action as stabilizer for polymer materials compared with a phosphonite/phosphinite according to the prior art.
Alternatively, a small amount of one or more nitrogen containing substances of the group consisting of carbonic acid amides, thiocarbonic acid amides, carbonic acid imides, thiocarbonic acid imides, lactames, thiolactames, carbonic acid hydrazides, urea, thiourea, symmetrically and asymmetrically substituted urea and thiourea derivatives, urethanes, uretimides as well as guanidine and its salts or melamine and derivatives thereof, including polymeric compounds of all named classes, or an oxide, hydroxide, (hydrogen)carbonate or (hydrogen)phosphate of a metal may be used alone or, preferably, in combination with a protic compound as defined above and leads to a similar result as described above.
Furthermore, combinations of one or more protic compounds and/or of one or more nitrogen containing substances (all as defined above) with an oxide, hydroxide, (hydrogen)carbonate or (hydrogen)phosphate of a metal can be used to improve the properties of phosphonites/phosphinites as described above.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The invention therefore relates to a process for preparing phosphonites or phosphinites of the general formula (I)
where
aryl is a substituted or unsubstituted aryl or heteroaryl radical;
R is any organic radical having 1-36 carbon atoms, which can also contain hetero atoms; and
A is either R or OR,
by reacting a product of a Friedel-Crafts reaction of the general formula (II)
where
aryl has the meaning above;
Hal is halogen; and
A′ is either Hal or R,
with a compound of the general formula (III)
R—OH (III)
where R has the meaning above, and separating off the byproducts formed, characterized in that an aftertreatment is carried out with a protic compound such as alcohols, ammonia, primary or secondary amines or water, or with an oxide, hydroxide, (hydrogen)carbonate or (hydrogen)phosphate of a metal, or with a nitrogen containing compound of the group consisting of carbonic acid amides, thiocarbonic acid amides, carbonic acid imides, thiocarbonic acid imides, lactames, thiolactames, carbonic acid hydrazides, urea, thiourea, symmetrically and asymmetrically substituted urea and thiourea derivatives, urethanes, uretimides as well as guanidine and its salts or melamine and derivatives thereof, including polymeric compounds of all named classes, or in any combination of one or more substances of the above mentioned compound classes, in the absence of solvent or in an inert, nonpolar solvent and the resultant byproducts are again separated off.
The reaction with the agents of the invention takes place either in the absence of solvent or in inert, nonpolar solvents such as alkanes or aromatics (eg. benzene, toluene, xylenes, pyridine) or their mixtures, but particularly preferably in alkanes (e.
Gronmaier Ernst
Staniek Peter
Clariant Finance (BVI) Limited
Hanf Scott E.
Jackson Susan S.
Lambkin Deborah C.
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