Seeded emulsion polymerization process for latexes and aqueous inkjet ink compositions made therefrom
Methods for forming latexes are provided. In embodiments, such a method comprises adding a first portion of a monomer emulsion comprising water, a monomer, an acidic monomer, a multifunctional monomer, and a first reactive surfactant to a reactive surfactant solution comprising water and a second reactive surfactant to form a reaction mixture, wherein the reactive surfactant solution does not comprise monomers other than the second reactive surfactant; adding a first portion of an initiator solution to the reaction mixture so that monomers undergo polymerization reactions to form resin seeds in the reaction mixture; adding a second portion of the monomer emulsion to the reaction mixture comprising the resin seeds; and adding a second portion of the initiator solution to the reaction mixture to form a latex comprising resin particles.
1. A method for forming a latex, the method comprising:
(a) adding a first portion of a monomer emulsion comprising water, a monomer, an acidic monomer, a multifunctional monomer, and a first reactive surfactant to a reactive surfactant solution comprising water and a second reactive surfactant to form a reaction mixture, wherein the reactive surfactant solution does not comprise monomers other than the second reactive surfactant;
(b) adding a first portion of an initiator solution to the reaction mixture so that monomers undergo polymerization reactions to form resin seeds in the reaction mixture;
(c) adding a second portion of the monomer emulsion to the reaction mixture comprising the resin seeds; and
(d) adding a second portion of the initiator solution to the reaction mixture of step b or the reaction mixture of step c to form a latex comprising resin particles.
2. The method of claim 1 , wherein the reactive surfactant solution does not comprise the initiator.
3. The method of claim 1 , wherein step (d) occurs after step (c).
4. The method of claim 1 , wherein the addition of the second portion of the initiator solution is carried out during the addition of the second portion of the monomer emulsion.
5. The method of claim 1 , wherein the monomer emulsion comprises styrene and an alkyl acrylate at a weight ratio of (styrene):(alkyl acrylate) of from about 10:1 to about 1:1.
6. The method of claim 1 , wherein the monomer emulsion is free of styrene.
7. The method of claim 1 , wherein the monomer emulsion comprises two different alkyl acrylates.
8. The method of claim 7 , wherein the two different alkyl acrylates are methyl (meth)acrylate and butyl (meth)acrylate which are present at a weight ratio of (methyl (meth)acrylate):(butyl (meth)acrylate) of from about 5:1 to about 1:5.
9. The method of claim 1 , wherein the monomer emulsion does not comprise a surfactant and the reactive surfactant solution does not comprise a surfactant.
10. The method of claim 1 , wherein the monomer emulsion comprises styrene, an alkyl acrylate, methacrylic acid, a sulfonic acid monomer, a poly(ethylene glycol) diacrylate, and an anionic ether sulfate reactive surfactant.
11. The method of claim 10 , wherein the sulfonic acid monomer is styrenesulfonic acid.
12. The method of claim 1 , wherein the monomer emulsion comprises two different alkyl acrylates, methacrylic acid, a sulfonic acid monomer, a poly(ethylene glycol) diacrylate, and an anionic ether sulfate reactive surfactant.
13. The method of claim 12 , wherein the sulfonic acid monomer is styrenesulfonic acid.
14. The method of claim 12 , wherein the monomer emulsion further comprises a hydrophilic monomer.
15. The method of claim 14 , wherein the hydrophilic monomer is a poly(ethylene glycol) methacrylate.
16. The method of claim 12 , wherein the two different alkyl acrylates are methyl (meth)acrylate and butyl (meth)acrylate.
17. The method of claim 12 , wherein the monomer emulsion is free of styrene.
18. The method of claim 1 , wherein the resin particles have a D 50 particle size of no greater than about 100 nm, a D 95 particle size of less than about 150 nm, and a width of no greater than about 45 nm.
19. The method of claim 18 , wherein the resin particles have a D 50 particle size of no greater than about 75 nm, a D 95 particle size of less than about 100 nm, and a width of no greater than about 35 nm.