Metal surfaces to inhibit ethylenically unsaturated monomer polymerization
Materials for making apparatus and a method of inhibiting polymerization during manufacture, purification, handling and storage of subject ethylenically unsaturated monomers are disclosed. In particular, copper or metals containing copper, in the presence of oxygen, have inhibit undesired polymerization resulting in polymer fouling in apparatus used during the manufacture, purification, handling and storage of the monomers, such as acrylic acid, methacrylic acid, acrylic acid esters and methacrylic acid esters. The copper or copper alloys as described herein, in the presence of an oxygen-containing gas, exhibit self-inhibiting surface characteristics when used to make at least a portion of the apparatus to inhibit polymerization of the monomers in contact with the portion of the apparatus including such copper-containing metal.
1. A method for inhibiting polymerization during at least one of manufacture, purification, handling and storage of a subject ethylenically unsaturated monomer, the method comprising the steps of:
introducing the monomer into apparatus for at least one of the manufacture, purification, handling and storage of the monomer, at least a portion of the apparatus in contact with the ethylenically unsaturated monomer selected from the group consisting of acrylic acid, an alpha alkyl acrylic acid, an alpha alkyl acrylic ester, a beta alkyl acrylic acid, a beta alkyl acrylic ester, methacrylic acid, an ester of acrylic acid other than methyl acrylate and 2-ethylhecyl acrylate, an ester of methacrylic acid, vinyl acetate, a vinyl acetate, a vinyl ester, a polyunsaturated carboxylic acid, a polyunsaturated ester, maleic acid, a maleic ester, maleic anhydride, and acetoxystyrene comprising a metal alloy containing sufficient copper to inhibit, in the presence of a gas containing oxygen, polymerization of the monomer within the apparatus, wherein said metal alloy comprises more than 40% nickel and cobalt, 25% to less than 60% copper and not more than 2.5% iron; and
providing a gas containing oxygen in the interior of the apparatus containing the monomer;
thereby inhibiting polymerization of the monomer in the apparatus.
2. The method of claim 1 , wherein the alkyl group is a straight chain or branched alkyl group having 1 to 8 carbon atoms.
3. The method of claim 2 , wherein the alkyl group is a straight or branched alkyl group having 1 to 4 carbon atoms.
4. The method of claim 1 wherein the ethylenically unsaturated monomer is acrylic acid.
5. The method of claim 1 wherein the ethylenically unsaturated monomer is ethyl acrylate.
6. The method of claim 1 wherein the ethylenically unsaturated monomer is butyl acrylate.
7. The method of claim 1 , wherein the metal alloy contains about 30% to about 50% copper.
8. The method of claim 1 wherein the apparatus is selected from the group consisting of distillation equipment, a distillation internal component, flame arrestor equipment, extraction tower equipment, absorption equipment, adsorption equipment, heat exchange equipment, piping, a fitting, valving, a pump and a container.
9. The method of claim 1 , wherein the apparatus is distillation equipment and the portion of the apparatus is packing.
10. The method of claim 1 , wherein the apparatus is a distillation column.
11. The method of claim 10 , wherein the oxygen-containing gas is provided through an inlet for the oxygen-containing gas at a lower portion of the distillation column.
12. The method of claim 1 , wherein the apparatus is a distillation column and the portion comprises trays for the distillation column.
13. The method of claim 1 , wherein the oxygen-containing gas is provided through an inlet for the oxygen-containing gas at a lower portion of the apparatus.
14. The method of claim 1 , wherein the oxygen-containing gas is air.
15. The method of claim 1 , wherein the oxygen-containing gas contains about 5 volume % oxygen.