Process for maleating polymerization residues and products
View Patent ↗A process for converting distillation residues obtained from polymerization processes to useful maleated products is provided.
1. A process for the maleation of a distillation residue containing 4 to 10 weight percent hydrocarbon diluent, 5 to 20 weight percent polyethylene having a density of 0.940 to 0.955 g/cm 3 and melt index according to ASTM D 1238-01, condition 190/2.16 of 0.02 to 0.3 g/10 min, 60 to 90 weight percent polyethylene wax having a number average molecular weight from 100 to 30000 and 0.2 to 1 weight percent catalyst residue, comprising:
(a) treating the distillation residue to remove hydrocarbon diluent;
(b) incorporating 1 to 10 weight percent maleic anhydride, based on the weight of the distillation residue;
(c) incorporating 0.25 to 6 weight percent organic peroxide, based on the weight of the distillation residue;
(d) heating the mixture above the decomposition temperature of the organic peroxide until the maleic anhydride is reacted; and
(e) recovering the maleated product.
2. The process of claim 1 wherein the hydrocarbon diluent is hexane.
3. The process of claim 1 wherein (a) is conducted at a temperature in the range 120° C. to 150° C.
4. The process of claim 1 wherein the residue treated in accordance with (a) contains less than 200 ppm hydrocarbon.
5. The process of claim 1 wherein the maleic-anhydride incorporation is carried out in the melt state.
6. The process of claim 5 wherein the amount of maleic anhydride incorporated is from 1.5 to 8 weight percent.
7. The process of claim 1 wherein the organic peroxide incorporation is carried out in the melt state at a temperature below the decomposition temperature of the organic peroxide.
8. The process of claim 7 wherein the amount of the organic peroxide incorporated is from 0.5 to 5 weight percent.
9. The process of claim 1 wherein (d) is conducted at a temperature in the range 103° C. to 200° C.
10. The maleated product produced by the process of claim 1 which contains from 0.5 to 7 weight percent bound maleic anhydride.
11. The maleated product of claim 10 further characterized by having shear dependent viscosity.
12. A process for the maleation of a distillation residue obtained from a process for the polymerization of ethylene, said distillation residue containing 4 to 10 weight percent hydrocarbon diluent, 5 to 20 weight percent polyethylene having a density of 0.940 to 0.955 g/cm 3 and melt index according to ASTM D 1238-01, condition 190/2.16 of 0.02 to 0.3 g/10 mm, 60 to 90 weight percent polyethylene waxes having a number average molecular weight from 100 to 30000 and 0.2 to 1 weight percent catalyst residue, comprising:
(a) heating the distillation residue at a temperature of 120° C. to 150° C. to remove hydrocarbon diluent;
(b) maintaining the residue obtained from (a) containing less than 200 ppm hydrocarbon diluent in a molten state and incorporating from 1 to 10 weight percent maleic anhydride;
(c) incorporating 0.25 to 6 weight percent organic peroxide into the melt containing the maleic anhydride from (b) while maintaining the temperature of said melt below the decomposition temperature of the organic peroxide;
(d) increasing the temperature of the mixture from (c) above the decomposition temperature of the organic peroxide and maintaining until the maleic anhydride is reacted; and
(e) recovering the maleated product.