STABILISING COMPOSITION
The invention concerns a stabilising composition, comprising: at least one antioxidant comprising one or more of: a phenolic antioxidant, a phosphite antioxidant, a sulphur-containing antioxidant, and an aminic antioxidant; and at least one buffering agent, wherein the buffering agent has the capacity to buffer in aqueous solution at a pH range from 4 to 8.
1 . A stabilising composition comprising:
a. at least one antioxidant composition comprising one or more of:
i. a phenolic antioxidant;
ii. a phosphite antioxidant;
iii. a sulphur-containing antioxidant; and
iv. an aminic antioxidant; and
b. at least one buffering agent, wherein the buffering agent has the capacity to buffer, in aqueous solution, at a pH range from 4 to 8.
2 . The stabilising composition according to claim 1 , wherein the buffering agent is a solid at a temperature of 50° C. or lower, and 1 atmosphere of pressure.
3 . The stabilising composition according to claim 1 , wherein the buffering agent has a molecular weight of less than about 500.
4 . The stabilising composition according to claim 1 , wherein the buffering agent comprises one or more metal phosphates and/or metal pyrophosphates.
5 . The stabilising composition according to claim 1 , wherein the buffering agent comprises a mixture of two or more metal phosphates and/or metal pyrophosphates.
6 . The stabilising composition according to claim 1 , wherein the buffering agent comprises a mixture of at least one monobasic alkali metal phosphate and at least one dibasic alkali metal phosphate.
7 . The stabilising composition according to claim 1 , wherein the buffering agent comprises one or more amino acids and/or alkali metal salts thereof.
8 . The stabilising composition according to claim 7 , wherein the amino acid and/or the alkali metal salt thereof is selected from the group consisting of glycine, cysteine, cystine, methionine, tyrosine, histidine, arginine glutamic acid, and combinations thereof.
9 . The stabilising composition according to claim 1 , wherein the buffering agent is present in an amount ranging from about 1% to about 50% by weight of the stabilising composition.
10 . The stabilising composition according to claim 1 , wherein the stabilising composition further comprises a secondary inorganic antioxidant.
11 . The stabilising composition according to claim 10 , wherein the secondary inorganic antioxidant is selected from the group consisting of a metal hypophosphite, a metal thiosulphate, a metal bisulphite, a metal metabisulphite, a metal hydrosulphite, and combinations thereof.
12 . The stabilising composition according to claim 11 , wherein the metal of the hypophosphite, thiosulphate, bisulphite, metabisulphite or hydrosulphite is an alkali metal and/or an alkaline earth metal.
13 . The stabilising composition according to claim 11 , wherein the secondary inorganic antioxidant is a metal hypophosphite, and the metal hypophosphite is an anhydrous or hydrated metal hypophosphite.
14 . The stabilising composition according to claim 10 , wherein the ratio of the buffering agent to the secondary inorganic antioxidant ranges from 5:95 to 95:5.
15 . The stabilising composition according to claim 1 , wherein the antioxidant composition comprises a phenolic antioxidant, and the phenolic antioxidant is a semi-hindered or a hindered phenolic antioxidant.
16 . The stabilising composition according to claim 15 , wherein the phenolic antioxidant is present in an amount ranging from about 1% to about 50% by weight of the stabilising composition.
17 . The stabilising composition according to claim 1 , wherein the antioxidant composition comprises a phosphite antioxidant, and the phosphite antioxidant is an organophosphite antioxidant.
18 . The stabilising composition according to claim 17 , wherein the phosphite antioxidant is present in an amount ranging from about 20% to about 90% by weight of the stabilising composition.
19 . The stabilising composition according to claim 1 , wherein the antioxidant composition comprises a sulfur-containing antioxidant, and the sulphur-containing antioxidant comprises one or more thioether groups and one or more ester groups.
20 . The stabilising composition according to claim 19 , wherein the sulphur-containing antioxidant is present in an amount ranging from about 1% to about 50% by weight of the stabilising composition.
21 . The stabilising composition according to claim 1 , wherein the antioxidant composition comprises a phenolic antioxidant and a phosphite antioxidant.
22 . The stabilising composition according to claim 1 , wherein the antioxidant composition comprises a phenolic antioxidant, a phosphite antioxidant and a sulphur-containing antioxidant.
23 . (canceled)
24 . A stabilised polymeric composition comprising a polymeric base material and a stabilising composition according to claim 1 .
25 . The stabilised polymeric composition according to claim 24 , wherein the stabilising composition is present in an amount ranging from about 0.01% to about 5% by weight of the stabilised polymeric composition.