Patent ID: 8859638

Claim:
A method for making a cross-linked ethylene propylene diene terpolymer latex with a customer specified solids content from 30 weight percent to 60 weight percent based on the total weight of the latex, the method comprising: a. blending 15 weight percent to 88 weight percent of a premixed liquid ethylene propylene diene terpolymer component, with 10 weight percent to 70 weight percent of a water and 1 weight percent to 30 weight percent of a surfactant, wherein the premixed liquid ethylene propylene diene terpolymer component comprises: (i) 4 weight percent to 50 weight percent of a solid polymer with a molecular weight from 1300000 Mw to 5000 Mw consisting of: a random covalently linked monomers of ethylene and propylene having weight ratios from 40:60 to 85:15 of ethylene:propylene respectively; and wherein 0.25 weight percent to 15 weight percent of the solid polymer is a non-conjugated diene; and (ii) 50 weight percent to 96 weight percent of a solvent; b. performing a mixing using the premixed liquid ethylene propylene diene terpolymer component, water and surfactant at an atmospheric pressure from 0.5 to 1.25 atmospheres until an homogenous uniform intermediate latex is formed; c. adding a first curative to the intermediate latex, forming a latex with curative; d. applying a first heating to the latex with curative at a temperature ranging from 40 degrees Celsius to 100 degrees Celsius, at a pressure from 0.5 to 1.25 atmospheres to remove 95 weight percent to 99 weight percent of the solvent, thereby forming a partially cross-linked latex; e. testing the partially cross-linked latex for crosslink density using ASTM test D3616 effective 2014 and if the ASTM test reveals a crosslink density less than a preset limit, adding at least one of: additional first curative and a second curative to achieve a total weight percent from 0.3 weight percent and 1.76 weight percent and further, wherein the first and second curatives are at least one of: a sulfur donating curative, and a free radical generating curative; and f. applying a second heating to the partially cross-linked latex to remove a quantity of water using a temperature ranging from 50 degrees Celsius to 100 degrees Celsius for 10 minutes to 60 minutes sufficient to form a cross-linked ethylene propylene diene terpolymer latex with a customer specified solids content from 30 weight percent to 60 weight percent solids based on the total weight of the latex and wherein the ethylene propylene diene polymer is cross-linked from 30 percent to 100 percent.