Phosphite compositions

Abstract

Solid phosphite compositions comprising tris(4-t-alkylphenyl) phosphites and selected hydroxyalkyl amines exhibit surprising performance compared with other phosphite stabilizers in the stabilization of polymers, such as polyolefins and the like, particularly in the prevention of color formation during high temperature processing or when exposed to certain gasses during storage, e.g., “gas fading”.

What is claimed is: 
     
         1 . A polymer stabilizing composition, comprising:
 (i) a first component comprising one or more phosphite antioxidants,
 wherein said one or more phosphite antioxidants comprise one or more solid tris(monoalkylaryl) phosphites, wherein the one or more solid tris(monoalkylaryl) phosphites is present in the composition in an amount exceeding 95 wt % with respect to the total amount of alkylaryl phosphite present in the composition; and 
   (ii) a second component comprising an alkanolamine.   
     
     
         2 . The composition according to  claim 1 , wherein
 (a) the one or more phosphite antioxidants comprise tris(monoalkylphenyl)phosphite, wherein greater than 95% by weight of all tris(phenyl) phosphite antioxidants alkylated at the ortho- or para-position relative to the phenoxy-phosphorus bond is one or more tris(4-monoalkylphenyl) phosphite of formula (I):   
       
         
           
           
               
               
           
         
       
       wherein each R is independently selected from C 1  to C 5  straight or branched chain alkyl;
 (b) the alkanolamine comprises one or more amines of formula (II): 
 
       
         
           
           
               
               
           
         
         wherein x is from 1 to 3; R 1  is selected from the group consisting of hydrogen, and straight or branched C 1 -C 6  alkyl, and R 2  is selected from the group consisting of straight or branched C 1 -C 30  alkyl, wherein the amine is present in an amount of from 0.01 to 5 wt % based on the total weight of phosphite antioxidants, and 
         the composition comprising (a) and (b) is a solid at 25° C. 
       
     
     
         3 . The composition according to  claim 2 , wherein R is selected from the group consisting of methyl, ethyl, propyl, 2-methylpropyl and 2,2-dimethylpropyl. 
     
     
         4 . The composition according to  claim 2 , wherein the at least one tris(4-monoalkylaryl) phosphite of formula (I) is selected from the group consisting of tris(4-t-butylphenyl) phosphite and tris(4-t-amylphenyl) phosphite. 
     
     
         5 . The composition according to  claim 2 , wherein 96 to 100% by weight of all phosphite antioxidants is one or more tris(4-monoalkylaryl)phosphite of formula (I). 
     
     
         6 . The composition according to  claim 2 , wherein in the amine (b) each R 1  is independently selected from the group consisting of hydrogen, straight or branched C 1 -C 3  alkyl and R 2  is a straight or branched C 8 -C 20  alkyl group. 
     
     
         7 . The composition according to  claim 6  wherein the amine is selected from the group consisting of triethanolamine, tripropanolamine, triisopropanolamine, octyl-bis(2-ethanol)amine, nonyl-bis(2-ethanol)amine, decyl-bis(2-ethanol)amine, undecyl-bis(2-ethanol)amine, dodecyl-bis(2-ethanol)amine, tridecyl-bis(2-ethanol)amine, tetradecyl-bis(2-ethanol)amine, pentadecyl-bis(2-ethanol)amine, hexadecyl-bis(2-ethanol)amine, heptadecyl-bis(2-ethanol)amine, octadecyl-bis(2-ethanol)amine, octyl-bis(2-propanol)amine, nonyl-bis(2-propanol)amine, decyl-bis(2-propanol)amine, undecyl-bis(2-propanol)amine, dodecyl-bis(2-propanol)amine, tridecyl-bis(2-propanol)amine, tetradecyl-bis(2-propanol)amine, pentadecyl-bis(2-propanol)amine, hexadecyl-bis(2-propanol)amine, heptadecyl-bis(2-propanol)amine, octadecyl-bis(2-propanol)amine, and isomers thereof. 
     
     
         8 . The composition according to  claim 7  wherein the amine (b) is selected from the group consisting of triethanolamine, tripropanolamine, triisopropanolamine, 
     
     
         9 . The composition according to  claim 2 , wherein the amine is present in an amount of from 0.1 to 3 wt % based on the total weight of phosphite antioxidants. 
     
     
         10 . The composition of  claim 1 , further comprising a polymer blended with or otherwise incorporating said polymer stabilizing composition, thereby generating a stabilized polymeric composition. 
     
     
         11 . The composition of  claim 10 , wherein the stabilized polymeric composition comprises from 0.01 to 10% of the polymer stabilizing composition. 
     
     
         12 . The composition of  claim 10 , wherein the at least one tris(monoalkylaryl)phosphite is selected from the group consisting of tris(4-t-butylphenyl) phosphite and tris(4-t-amylphenyl) phosphite,
 wherein the alkanolamine is selected from the group consisting of triethanolamine, tripropanolamine and triisopropanolamine, and   wherein the alkanolamine is present in an amount of from 0.5 to 1.5 wt % based on the total weight of phosphite antioxidants present in the composition.   
     
     
         13 . The composition of  claim 10 , wherein the polymer comprises a homopolymer, co-polymer, plastomer, elastomer or blend comprising any two or more thereof. 
     
     
         14 . A polymer stabilizing composition, comprising:
 (i) a first component comprising at least one phosphite antioxidant,
 wherein said at least one phosphite antioxidant comprises solid tris(monoalkylaryl) phosphite, 
 wherein the solid tris(monoalkylaryl) phosphite is present in the composition in an amount from 96 to 100 wt % with respect to the total amount of alkylaryl phosphite present in the composition; and 
   (ii) a second component comprising an alkanolamine,
 wherein the alkanolamine is present in an amount of from 0.1 to 3 wt % based on the total weight of the at least one phosphite antioxidant. 
   
     
     
         15 . The polymer stabilizing composition according to  claim 14 , wherein the solid tris(monoalkylaryl) phosphite comprises a tris(4-monoalkylphenyl) phosphite of formula (I): 
       
         
           
           
               
               
           
         
         wherein each R is independently selected from C 1  to C 5  straight or branched chain alkyl. 
       
     
     
         16 . The polymer stabilizing composition according to  claim 15 ,
 further comprising a polymer of a type selected from the group consisting of homopolymers, co-polymers, plastomers, elastomers, and a blend comprising any two or more thereof, and   wherein the polymer is stabilized and exhibits improvements in one or more of melt flow index, yellowness index, and gas fade properties, as compared to a polymer in the absence of the polymer stabilizing composition.   
     
     
         17 . A polymer stabilizing composition, comprising:
 (i) a first component comprising at least one phosphite antioxidant,
 wherein said at least one phosphite antioxidant comprises a tris(4-monoalkylphenyl) phosphite of formula (I): 
   
       
         
           
           
               
               
           
         
         
           wherein each R is independently selected from C 1  to C 5  straight or branched chain alkyl; and 
         
         (ii) a second component comprising an alkanolamine,
 wherein the alkanolamine is selected from the group consisting of triethanolamine, tripropanolamine and triisopropanolamine, and 
 
         wherein the polymer stabilizing composition is a solid at 25° C. 
       
     
     
         18 . The polymer stabilizing composition of  claim 17 , wherein the tris(4-monoalkylphenyl) phosphite is solid, and wherein each R in formula (I) is the same. 
     
     
         19 . The polymer stabilizing composition of  claim 17 , wherein the alkanolamine is triisopropanolamine. 
     
     
         20 . The polymer stabilizing composition of  claim 17 , wherein the tris(4-monoalkylphenyl) phosphite comprises one or more of tris(4-t-butylphenyl) phosphite and tris(4-t-amylphenyl) phosphite.