Claims
- 1. A multi-stage aqueous emulsion polymer suitable for use in dirt pickup resistant coatings comprising(i) a first polymer comprising at least one nonionic copolymerized monoethylenically unsaturated monomer, from 0.5% to 7% of a copolymerized monoethylenically unsaturated ionic monomer, based on the weight of said first polymer, and from 0% to 1.0%, based on the weight of said first polymer, of a copolymerized multi-ethylenically unsaturated monomer, said first polymer having a Tg of 15° C. to 105° C.; and (ii) a second polymer comprising at least one nonionic copolymerized monoethylenically unsaturated monomer, from 0% to 2% of a copolymerized monoethylenically unsaturated ionic monomer, and from 0.25% to 6%, based on the weight of said second polymer, copolymerized multi-ethylenically unsaturated monomer, said second polymer having a Tg of −55° C. to 30° C., said second polymer having a different composition than said first polymer, and said second polymer being from 25% to 75% of the total weight of said first polymer and said second polymer, based on dry polymer weights.
- 2. The multi-stage aqueous emulsion polymer of claim 1 wherein said first polymer is prepared in a first stage and said second polymer is prepared in the presence of said first polymer.
- 3. The multi-stage emulsion polymer of claim 1 or claim 2 further comprising a copolymerized monomer selected from monomers consisting of monoethylenically unsaturated acetophenone derivatives, monoethylenically unsaturated benzophenone derivatives, and mixtures thereof.
- 4. A method for providing a dirt pickup resistant coating comprising(a) forming an aqueous coating composition comprising a multi-stage aqueous emulsion polymer comprising (i) a first polymer comprising at least one nonionic copolymerized monoethylenically unsaturated monomer, from 0.5% to 7% of a copolymerized monoethylenically unsaturated ionic monomer, based on the weight of said first polymer, and from 0% to 1.0%, based on the weight of said first polymer, of a copolymerized multi-ethylenically unsaturated monomer, said first polymer having a Tg of 15° C. to 105° C.; and (ii) a second polymer comprising at least one nonionic copolymerized monoethylenically unsaturated monomer, from 0% to 2% of a copolymerized monoethylenically unsaturated ionic monomer, and from 0.25% to 6%, based on the weight of said second polymer, copolymerized multi-ethylenically unsaturated monomer, said second polymer having a Tg of −55° C. to 30° C., said second polymer having a different composition than said first copolymer, and said second polymer being from 25% to 75% of the total weight of said first polymer and said second polymer, based on dry polymer weights. (b) applying said aqueous coating composition to a substrate, and (c) drying, or allowing to dry, said applied aqueous coating composition.
- 5. The method of claim 4 wherein said first polymer is prepared in a first stage and said second polymer is prepared in the presence of said first polymer.
- 6. The method of claim 4 wherein said multi-stage polymer further comprises a copolymerized monomer selected from monomers consisting of monoethylenically unsaturated acetophenone derivatives, monoethylenically unsaturated benzophenone derivatives, and mixtures thereof.
- 7. The method of claim 4 or claim 5 or claim 6 wherein said aqueous coating composition further comprises a photosensitive compound selected from the group consisting of non-ethylenically unsaturated acetophenone derivatives and non-ethylenically unsaturated benzophenone derivatives.
Parent Case Info
This is a nonprovisional application of prior pending provisional application Ser. No. 60/111,362 filed Dec. 8, 1998.
US Referenced Citations (4)
Foreign Referenced Citations (2)
Number |
Date |
Country |
3106489 |
Mar 1989 |
AU |
0522791 A1 |
Jul 1992 |
EP |
Provisional Applications (1)
|
Number |
Date |
Country |
|
60/111362 |
Dec 1998 |
US |