Aromatic diamine polyurethane curatives with improved stability
View Patent ↗Disclosed herein is a composition comprising an aromatic diamine that is a solid at room temperature and a stabilizing quantity of a hindered amine light stabilizer and its use as a polyurethane curing agent.
1. A stabilized methylene bis-orthochloroaniline composition consisting essentially of:
a) a technical grade methylene bis-orthochloroaniline composition consisting essentially of
i) 7-8 weight percent of a triamine analog of the methylene bis-orthochloroaniline, wherein the triamine analog contains three aromatic rings, and
ii) 90 weight percent of methylene bis-orthochloroaniline, wherein the weight percentages are based on the total weight of the technical grade methylene bis-orthochloroaniline composition; and
b) a stabilizing quantity of a hindered amine light stabilizer.
2. The methylene bis-orthochloroaniline composition of claim 1 wherein the hindered amine light stabilizer is present at a level of 0.01 to 5 weight percent based on the total weight of the technical grade methylene bis-orthochloroaniline composition.
3. The methylene bis-orthochloroaniline composition of claim 1 , wherein the hindered amine light stabilizer is a (1,2,2,6,6-pentamethyl-4-piperidinyl) sebacate.
4. A method of stabilizing a technical grade methylene bis-orthochloroaniline composition consisting essentially of
i) 7-8 weight percent of a triamine analog of the methylene bis-orthochloroaniline, wherein the triamine analog contains three aromatic rings, and
ii) 90 weight percent of methylene bis-orthochloroaniline, wherein the weight percentages are based on the total weight of the technical grade methylene bis-orthochloroaniline composition from the effects of degradation by heat comprising blending with said technical grade methylene bis-orthochloroaniline composition a stabilizing quantity of a hindered amine light stabilizer to produce a stabilized methylene bis-orthochloroaniline composition consisting essentially of the technical grade methylene bis-orthochloroaniline composition and the hindered amine light stabilizer.
5. The method of claim 4 wherein the hindered amine light stabilizer is present at a level of 0.01 to 5 weight percent based on the total weight of the technical grade methylene bis-orthochloroaniline composition.
6. The method of claim 4 , wherein the hindered amine light stabilizer is a (1,2,2,6,6-pentamethyl-4-piperidinyl) sebacate.
7. In a method for the production of polyurethane elastomers comprising the mixing and curing of a polyurethane prepolymer with a technical grade methylene bis-orthochloroaniline composition consisting essentially of
i) 7-8 weight percent of a triamine analog of the methylene bis-orthochloroaniline, wherein the triamine analog contains three aromatic rings, and
ii) 90 weight percent of methylene bis-orthochloroaniline, wherein the weight percentages are based on the total weight of the technical grade methylene bis-orthochloroaniline composition,
the improvement that comprises blending a stabilizing quantity of a hindered amine light stabilizer with the technical grade methylene bis-orthochloroaniline composition to stabilize the methylene bis-orthochloroaniline to produce a stabilized methylene bis-orthochloroaniline composition consisting essentially of the technical grade methylene bis-orthochloroaniline composition and the hindered amine light stabilizer.
8. The method of claim 7 wherein the hindered amine light stabilizer is present at a level of 0.01 to 5 weight percent based on the total weight of the technical grade methylene bis-orthochloroaniline composition.
9. The method of claim 7 , wherein the hindered amine light stabilizer is a (1,2,2,6,6-pentamethyl-4-piperidinyl) sebacate.