Claims
- 1. In a pressure-sensitive adhesive comprised of emulsion polymerized units of (a) from 60 to 95 percent by weight of at least one at least one C6-12 alkyl acrylate; (b) from 0 to 10 percent by weight of ethylenically unsaturated compounds having a glass transition temperature of above 0° C. and contain no functional groups other than an ethylenically unsaturated group; (c) from 0 to 10 percent by weight of ethylenically unsaturated compound having at least one acid or acid anhydride group; and (d) from 0 to 20 percent by weight of further ethylenically unsaturated compounds, weight percentages based on the total weight of polymer, the improvement which comprises forming said pressure-sensitive adhesive by emulsion polymerization in the presence of a styrene containing polymer.
- 2. The pressure-sensitive adhesive of claim 1 wherein the group (a) monomer includes 2-ethylhexyl acrylate.
- 3. The pressure-sensitive adhesive of claim 2 wherein the group (b) monomer includes butyl acrylate or methyl methacrylate.
- 4. The pressure-sensitive adhesive of claim 1 wherein the pressure-sensitive adhesive is comprised of from 5 to 30 percent by weight styrene containing polymer based upon the combined weight of said pressure-sensitive adhesive and said styrene containing polymer and polystyrene is the styrene containing polymer.
- 5. The pressure-sensitive adhesive of claim 4 wherein the polystyrene is present in an amount from 10 to 20 percent by weight.
- 6. The pressure-sensitive adhesive of claim 5 wherein said aqueous pressure-sensitive adhesive has a Tg of from −45° C. to −75° C.
- 7. In a process for producing a pressure-sensitive adhesive comprised of emulsion polymerized units of (a) from 60 to 95 percent by weight of at least one at least one C6-12 alkyl acrylate; (b) from 0 to 10 percent by weight of ethylenically unsaturated compounds having a glass transition temperature of above 0° C. and contain no functional groups other than an ethylenically unsaturated group; (c) from 0 to 10 percent by weight of ethylenically unsaturated compound having at least one acid or acid anhydride group; and (d) from 0 to 20 percent by weight of further ethylenically unsaturated compounds, the weight percentages based on the total weight of polymer, the improvement which comprises forming said pressure-sensitive adhesive by emulsion polymerization in the presence of a styrene containing polymer.
- 8. The process of claim 7 wherein the styrene containing polymer is present in an amount from 5 to 30 percent by weight of the pressure-sensitive adhesive.
- 9. The process of claim 8 wherein said pressure-sensitive adhesive has a Tg of from −45° C. to −75° C.
- 10. The process of claim 9 wherein the pressure-sensitive adhesive is polymerized in the presence of a polystyrene latex as the styrene containing polymer.
- 11. The process of claim 10 wherein the pressure-sensitive adhesive includes polymerized units of least one ester of acrylic or methacrylic acid selected from the group consisting of a C1 to C8 alkyl acrylate or a C1 to C8 alkyl methacrylate.
- 12. The process of claim 11 wherein said C1 to C8 alkyl acrylate and C1 to C8 alkyl methacrylate is selected from the group consisting of methyl methacrylate and 2-ethylhexyl acrylate.
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a division of U.S. application Ser. No. 10/262,249, filed on Sep. 30, 2002, to be issued as U.S. Pat. No. 6,747,084 on Jun. 8, 2004.
Divisions (1)
|
Number |
Date |
Country |
Parent |
10262429 |
Sep 2002 |
US |
Child |
10858576 |
Jun 2004 |
US |