Stabilizer blend for improved chlorine resistance
A method for increasing the stability of a thermoplastic resin in the presence of water is disclosed wherein said method comprises adding to said resin a stabilizing amount of a blend consisting of: (1) an aromatic amine stabilizer; (2) a sterically hindered phenol; (3) optionally, one or more co-stabilizers; and (4) optionally, one or more additives selected from the group consisting of UV absorbers, light stabilizers, metal deactivators, peroxide scavengers, polyamide stabilizers, basic co-stabilizers, nucleating agents, fillers, reinforcing agents, aminoxy propanoate derivatives, plasticizers, epoxidized vegetable oils, lubricants, emulsifiers, pigments, optical brighteners, flame-proofing agents, anti-static agents, and blowing agents.
1 . A method for increasing the stability of a thermoplastic resin in the presence of water consisting of adding to said resin a stabilizing amount of a blend consisting of: (1) an aromatic amine stabilizer; (2) a sterically hindered phenol; (3) optionally, one or more co-stabilizers; and (4) optionally, one or more additives selected from the group consisting of UV absorbers, light stabilizers, metal deactivators, peroxide scavengers, polyamide stabilizers, basic co-stabilizers, nucleating agents, fillers, reinforcing agents, aminoxy propanoate derivatives, plasticizers, epoxidized vegetable oils, lubricants, emulsifiers, pigments, optical brighteners, flame-proofing agents, anti-static agents, and blowing agents.
2 . The method of claim 1 wherein the one or more co-stabilizers is selected from the group consisting of a phosphite, a phosphonite, a lactone, a hydroxylamine, a trialkyl amine oxide and a hydroxylamine.
3 . The method of claim 2 wherein the water is chlorinated.
4 . The method of claim 2 wherein the thermoplastic resin is a polyolefin.
5 . The pipe of claim 4 wherein the polyolefin is high density polyethylene.
6 . The method of claim 2 wherein the aromatic amine antioxidant is represented by the formula:
Ar—NH—Ar′
wherein Ar and Ar′ are independently selected substituted or unsubstituted aryl radicals.
7 . The method of claim 3 wherein the aromatic amine antioxidant is 4,4′-bis(α,α-dimethylbenzyl)diphenylamine.
8 . The method of claim 7 wherein the thermoplastic resin is a polyolefin.
9 . The pipe of claim 8 wherein the polyolefin is high density polyethylene.
10 . A pipe for transporting water wherein said pipe is prepared from a composition consisting of a thermoplastic resin and a stabilizing amount of a blend consisting of: (1) an aromatic amine stabilizer; (2) a sterically hindered phenol; (3) optionally, one or more co-stabilizers; and (4) optionally, one or more additives selected from the group consisting of UV absorbers, light stabilizers, metal deactivators, peroxide scavengers, polyamide stabilizers, basic co-stabilizers, nucleating agents, fillers, reinforcing agents, aminoxy propanoate derivatives, plasticizers, epoxidized vegetable oils, lubricants, emulsifiers, pigments, optical brighteners, flame-proofing agents, anti-static agents, and blowing agents.
11 . The method of claim 9 wherein the one or more co-stabilizers is selected from the group consisting of a phosphite, a phosphonite, a lactone, a hydroxylamine, a trialkyl amine oxide and a hydroxylamine.
12 . The pipe of claim 10 wherein the water is chlorinated.
13 . The pipe of claim 10 wherein the thermoplastic resin is a polyolefin.
14 . The pipe of claim 13 wherein the polyolefin is high density polyethylene.
15 . The pipe of claim 10 wherein the aromatic amine antioxidant is represented by the formula:
Ar—NH—Ar′
wherein Ar and Ar′ are independently selected substituted or unsubstituted aryl radicals.
16 . The pipe of claim 12 wherein the aromatic amine antioxidant is 4,4′-bis(α,α-dimethylbenzyl)diphenylamine.
17 . The pipe of claim 15 wherein the thermoplastic resin is a polyolefin.
18 . The pipe of claim 17 wherein the polyolefin is high density polyethylene.