Latex polymerization using a combination of reactive surfactants for traffic markings
The present disclosure provides latex compositions manufactured using a combination of reactive surfactants. The compositions are useful as road marking materials.
1. A latex formulation formed from a reaction mixture comprising:
at least one ethylenically unsaturated monomer, wherein the ethylenically unsaturated monomers comprise butyl acrylate and methyl methacrylate, and wherein butyl acrylate is present in a weight fraction of at least 0.45 based on the total amount of butyl acrylate and methyl methacrylate;
a reactive surfactant selected from the group consisting of a compound of formula (I)
where n is 1 or 2; x is 1-10; z is from about 5 to 60; Z − is SO 3 − or PO 3 2− ; and M + is Na + , K + , NH 4 + , or an alkanolamine;
a compound of formula (II)
where n is 1 or 2; x is 1-10; y is 0, 1, or 2; R is —H, -alkyl, or -alkylphenol; z is from about 5 to 60; and
a compound of formula (III)
where n is 1 or 2; x is 1-10; y is 0, 1, or 2; R is —H, -alkyl, or -alkylphenol; z is from about 5 to 60; M + is SO 3 − or PO 3 2 ; and M + is Na + , K + , NH 4 + , or an alkanolamine;
and wherein the latex formulation has a number-average particle size of 230 nm, and a particle size distribution of 1.2 as determined by dynamic light scattering.
2. The latex formulation of claim 1 , further comprising a pigment.
3. A method of making a latex formulation, comprising the steps of:
providing a seed composition comprising a reactive surfactant, and a redox initiator system, and at least one ethylenically unsaturated monomer wherein the ethylenically unsaturated monomers comprise butyl acrylate and methyl methacrylate, and wherein butyl acrylate is present in a weight fraction of at least 0.45 based on the total amount of butyl acrylate and methyl methacrylate,
heating the seed composition to 85° C.;
adding to the heated seed composition a pre-emulsion composition comprising a second redox initiator system, and a reactive surfactant selected from the group consisting of:
a compound of formula (I)
where n is 1 or 2; x is 1-10; z is from about 5 to 60; Z − is SO 3 − or PO 3 2− ; and M + is Na + , K + , NH 4 + , or an alkanolamine;
and
a compound of formula (II)
where n is 1 or 2; x is 1-10; y is 0, 1, or 2; R is —H, -alkyl, or -alkylphenol; z is from about 5 to 60; and
a compound of formula (III)
where n is 1 or 2; x is 2; y is 0, 1, or 2; z is from about 5 to 60; is SO 3 − or PO 3 2 ; and M + is Na + , K + , NH 4 − , or an alkanolamine; and
heating the combined seed composition and emulsion composition to 85° C. to provide a latex formulation, wherein the latex formulation has a number-average particle size of 230 nm and a particle size distribution of 1.2, as determined by dynamic light scattering.
4. The latex formulation of claim 2 , wherein the pigment comprises a titanium dioxide pigment.
5. The method of claim 3 wherein the latex formulation has a viscosity of 68 mPaS at 22.3° C.
6. The method of claim 3 , wherein the latex formulation has a T g of greater than or equal to 20° C.
7. The method of claim 3 , wherein the reactive surfactant is present in the latex formulation in an amount between 0.5 wt % to 1.5 wt %, based on the total weight of the latex formulation.
8. The method of claim 3 , wherein at least two different reactive surfactants are present in the latex formulation.
9. The method of claim 3 , wherein the at least two different reactive surfactants are present in the latex formulation in a total amount of 1.5 wt % to 5.0 wt %.
10. The method of claim 3 , wherein the latex formulation further comprises a pigment.
11. The method of claim 10 , wherein the pigment comprises titanium dioxide.
12. The latex formulation of claim 1 , wherein the latex formulation has a viscosity of 62-226 mPaS at 22.3° C.
13. The latex formulation of claim 1 , wherein at least two different reactive surfactants are present in the latex formulation.
14. The latex formulation of claim 1 , wherein the at least two different reactive surfactants are present in the latex formulation in a total amount of 1.5 wt % to 5.0 wt %.
15. The latex formulation of claim 1 , wherein the latex formulation has a T g of greater than or equal to 20° C.
16. A traffic paint composition, comprising the reaction products of
ethylenically unsaturated monomers comprising butyl acrylate and methyl methacrylate, and wherein butyl acrylate is present in a weight fraction of at least 0.45 based on the total amount of butyl acrylate and methyl methacrylate;
one or more reactive surfactants; and
a redox initiator,
wherein the traffic paint composition has a viscosity of 62-226 mPaS at 22.3° C., a total solids content of about 50 weight percent, a pH of 8.3 to 8.7; and a number-average particle size of 230 nm and a particle size distribution of 1.2, as determined by dynamic light scattering;
and wherein the traffic paint composition passes ASTM-7377 test of water wash-off resistance.
17. The latex formulation of claim 1 , where the latex formulation has a total solids content of about 50 weight percent.
18. The latex formulation of claim 1 , where the latex formulation has a pH of 8.3 to 8.7.
19. The latex formulation of claim 1 , wherein
the compound of formula (I) has x is 1; z is 16; Z − is SO 3 − ; and M + is NH 4 + ,
the compound of formula (II) has x is 1; and z is 16;
the compound of formula (III) has x is 2; and z is 15.