GB1076696A - Organic phosphites containing polycyclic aromatic groups and synthetic resin compositions containing the same - Google Patents

Abstract

Organic polyphosphite esters have at least one polycarbocyclic aromatic group attached to each phosphite wherein the carbocyclic nuclei are joined by a bivalent linking group other than a direct C-C link between ring carbons, a thioether group or a polysulphide group; and contain at least one aliphatic or cycloaliphatic group in the molecule, preferably also attached to a phosphite group; less than one phenolic -OH per phosphite group being present on the carbocyclic nuclei, and phosphite groups being joined only via the polycarbocyclic groups. The phosphites may have the general formula <FORM:1076696/C3/1> wherein m is an integer of 1 to 20, each Ar which may be the same or different, is a carbocyclic aromatic nucleus, Y is a linking group other than thioether or polysulphide or a direct link between ring carbons, and Z is hyrogen or organic monovalent or bivalent groups satisfying the remaining phosphite oxygen valences. The groups Ar may be substituted by up to four substituent groups, such as halogen, or alkyl, aryl or cycloalkyl radicals up to a total of 60 carbons per polycyclic group, such radicals usually not having more than 18 carbons each, or hydroxy groups, providing that the number of these groups is less than the total number of phosphite groups. The polycarbocyclic group, Ar-Y-Ar, may have from 10 to 60 carbon atoms and may include condensed aromatic rings; constituent groups include phenyl, naphthyl, phenanthryl, anthracenyl, pyrenyl, chrysenyl and fluorenyl. The linking group, Y, may be any bivalent group other than thioether or polysulphide, such as oxygen, C1 to C20 hydrocarbon such as alkylene, alkylidene, arylene, aralkylene, alkarylene or cycloalkene, and may include one or more oxygen or sulphur atoms. Y may also include aromatic groups having phenolic hydroxyl groups, providing such are less in number than the phosphite groups, and such -OH groups may be esterified by additional phosphite. Z may be any mono- or bivalent organic group, and may form a heterocycle with the phosphite group, and can include Ar groups as defined above. The polyphosphite are prepared by transesterification of an aryl, alkyl or alkylaryl phosphite with a polycyclic polyhydric phenol, when the alkyl or aryl radicals are replaced by polycyclic radicals, the reaction being continued until all available phenolic -OH, or at least sufficient thereof that there is below one such -OH per phosphite group, has been esterified. The structure of the product is dependent upon reaction conditions and reactant proportions; high temperatures and prolonged reaction times favour the production of three-dimensional cage-type polymers, and by avoidance of such conditions the reaction is directed to formation of linear polyphosphites as the preferred form. Linear polymers are also encouraged by introducing monovalent chain stoppers into the reaction system, either by use of an alkyl aryl phosphite as a starting material, of which the aryl groups are more easily replaceable by phenol, or, when a tri-aryl phosphite is used, by adding a monohydric phenol or alcohol with the polycyclic phenol. Also phenols which cyclize with the phosphite to form a heterocyclic O- and P-cotaining ring are preferred as producing linear polymers. The reaction is performed under anhydrous conditions, if required in a volatile alcoholic solvent, and preferably with a catalyst such as an alkaline earth- or alkali-metal, or an alkaline compound thereof, at a temperature of 40 DEG to 150 DEG C. Many examples are given, and numerous particular compounds of the invention are specified. Polyolefins and polyvinyl chlorides are stabilized with the polyphosphites or with monomeric phosphites of the general formula <FORM:1076696/C3/2> wherein each Ar represents a carbocyclic aromatic nucleus with no free phenolic -OH groups, and Z and Y are as descrieed above (see Division C2). When used in such compositions, the above proviso to the nature of the group Y does not apply, and hence Y may also be a thioether, or polysulphide group or a direct link between ring carbons. Polyvinyl chlorides include polyvinyl chloride homopolymers, after-chrlorinated polyvinyl chlorides, and copolymers of vinyl chloride with a minor proportion of copolymerizable monomers such as vinyl acetate, maleic or fumaric acids or esters, or styrene, and also mixtures of a major proportion of polyvinyl chloride with other resins such as chlorinated polyethylene or a copolymer of acrylonitrile, butadiene and styrene. The polyvinyl chloride compositions may be rigid or plasticized with di-octyl phthalate, octyl diphenyl phosphate, epoxidized soybean oil, and epoxy higher esters having from 22 to 150 carbon atoms, formed from epoxidization of esters unsaturated in the acid and/or alcohol portions. Other stabilizers may be present, such as metal soaps and various epoxy compounds. Parting agents, such as C12 to C24 aliphatic acids, mineral oils, polyvinyl stearate, polyethylene and paraffin wax may also be present. Polyolefins which are stabilized by the phosphites include polyethylene, polypropylene, polybutylene and higher polyolefins, such as poly(pentene-1), poly(3-methylbutene-1), poly-(4 - methylpentene - 1), polystyrene, and copolymers of the corresponding monomers with each other. Other stabilizers may be present, such as zinc 2-ethyl hexoate.ALSO:The invention comprises organic phosphite or polyphosphite esters wherein there is at least one polycarbocyclic aromatic group attached to each phosphite group, and an aliphatic or cycloaliphatic group in the molecule, preferably also on the phosphite group, with the provisos that the carbocyclic nuclei of the polycarbocyclic group are linked by a bivalent radical other than a direct bond between ring carbons, a direct thioether or a direct polysulphide link; that when a plurality of phosphite groups are present, they are joined only via polycarbocylic groups; and when phenolic hydroxy groups are present, less than one polycarbocyclic group per phosphite group possesses such hydroxy groups. Preferred monomeric phosphites have the general formula <FORM:1076696/C2/1> wherein each Ar represents an aromatic carbocyclic nucleus, having no free phenolic hydroxyls, Z is an aliphatic or cycloaliphatic group, and Y is a bivalent group other than a direct link between the carbons of the Ar groups, or a thioether or polysulphide group. Preferred polymeric phosphites have the structure <FORM:1076696/C2/2> wherein Ar represents an aromatic nucleus, on which may be present a number of free phenolic groups less than the total number of phosphite groups, or up to four other substituents such as halogen, alkyl, aryl, or cycloalkyl up to a total of 60 carbons per polycyclic group (or a total of 18 carbons per Ar group); m is 0 or an integer of 1 to 20; Z represents hydrogen, or monovalent or bivalent organic radicals satisfying the remaining phosphite oxygen valences, and including at least one aliphatic or cycloaliphatic group; and Y is a bivalent linking radical as above. Z may be alkyl, aryl, alkaryl or heterocyclic groups, and can be or include further groups of the type Ar-Y-Ar. The polycarbocyclic groups may comprise condensed or separate aromatic rings, and may include phenyl, naphthyl, phenanthryl, anthracenyl, pyrenyl, chrysenyl, and fluorenyl groups. Bivalent linking groups may be oxygen; C1 to C20 hydrocarbon, such as alkylene, alkylidene, arylene, aralkylene, alkarylene or cycloalkylene, and may include one or more oxygen or sulphur atoms, or may include aromatic groups having phenolic hydroxy substituents, with the proviso that there are less than one such group per phosphite group; such hydroxyls may be esterified by further phosphite groups. The phosphites are prepared by transesterification of aryl, aralkyl or alkyl phosphites with polycyclic polyhydric phenols, the process being carried sufficiently far to take up all available phenolic -OH, or at least enough that there is less than one such -OH per phosphite group. The reaction is directed towards the formation of linear polymers, such being preferred, rather than cage-type three-dimensional polymers, by avoidance of long reaction times and high temperatures, or by inclusion in the reaction system of monovalent chain stoppers (see Division C3). A catalyst is preferably used, such as an alkaline earth- or alkali-metal or an alkaline salt thereof, and the reaction is carried out at a temperature of 40 DEG C., under anhydrous conditions, if required in a volatile alcoholic solvent. Many examples are given for preparing the inventive compounds, and many of these compounds are specified by name. Also an example includes the preparation of 2,6-tris(21-hydroxy-31,5-dinonylbenzyl)-4 -nonylphenol, by reacting nonylphenol, dinonylphenol, and paraformaldehyde in boiling toluene with an oxalic acid catalyst, the said tris-phenol then being used to prepare a phosphite ester. The phosphites and polyphosphites are employed in resin compositions as stabilizers, in which use phosphites similar to those described but wherein the aforesaid proviso regarding the nature of the linking group Y, need not apply (see Division C3).