Claims
- 1. A method for preparing a tackified acrylic copolymer composition having increased peel strength while resisting loss of holding properties which comprises the steps of:
- (a) dissolving from about 10 to about 100 parts of a hydrogenated hydrocarbon resin, or a naturally occurring resin, per 100 parts in a liquid mixture of free-radical polymerizable monomers to form a polymerizable vinyl monomer reactant solution, the hydrocarbon resin, or the naturally occurring resin, having a molecular weight of from about 500 to about 5000 and an aromatic content of at least 10% by weight;
- (b) emulsifying the reactant solution in an aqueous medium;
- (c) polymerizing the emulsified monomers, in the absence of oxygen, in the presence of the resin, a free-radical polymerization initiator and small, but effective, amount of polymerizable crosslinking monomer to form an acrylic copolymer latex; and
- (d) recovering the tackified acrylic copolymer latex.
- 2. The method of claim 1 wherein the crosslinking monomer is present in an amount of from about 0.1 wt. % to about 3 wt. % of the monomer reactant solution.
- 3. The method of claim 2 wherein the crosslinking monomer is mixed and added with the polymerizable monomers after the polymerization has begun.
- 4. The method of claim 3 wherein the crosslinking monomers is mixed and added to the polymerization with the last 25% of the polymerizable monomers.
- 5. The method of claim 1 wherein the monomer solution comprises from about 1 to about 15 wt. % of a (meth) acrylic acid, from 0 to about 50 wt. % of a lower alkyl (meth) acrylate ester and from about 25 wt. % to about 99 wt. % of an upper alkyl (meth) acrylate ester.
- 6. The method of claim 1 wherein the monomer solution comprises from about 2 wt. % to about 6 wt/% (meth) acrylic acid, from about 10 wt % to about 35 wt. % of a lower alkyl (meth) acrylate acid, and from about 60 wt. % to about 88 wt. % of an upper alkyl (meth) acrylate.
- 7. The method of claim 1 wherein the resin is a hydrogenated petroleum hydrocarbon resin, or a naturally occurring resin, having an average molecular weight of from about 100 to about 2500 and an aromatic content of from about 10 wt. % to about 65 wt. % and the monomers include from about 2 wt. % to about 6 wt. % acrylic acid, from about 10 wt. % to about 35 wt. % ethyl acrylate and from about 60 wt. % to about 88 wt. % 2-ethylhexyl acrylate, wherein the resin is present in the monomer reactant solution in amounts of from about 20 to about 55 parts resin per 100 parts monomers polymerized.
Parent Case Info
This is a division of application Ser. No. 444,460, filed Dec. 1, 1989 now U.S. Pat. No. 5,013,784 which is a continuation in part of 367,829 filed Jun. 19, 1989. Now abandoned.
US Referenced Citations (1)
Number |
Name |
Date |
Kind |
4645711 |
Winszow et al. |
Feb 1982 |
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Divisions (1)
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Number |
Date |
Country |
Parent |
444460 |
Dec 1989 |
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Continuation in Parts (1)
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Number |
Date |
Country |
Parent |
367829 |
Jun 1989 |
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