Low molecular weight polystyrene resin and methods of making and using the same
AssigneeEastman Chemical Company
InventorsWei Min Cheng, Puthenkovilakom Rajesh Raja, George Joseph Kutsek, John B. Penn
Life of this patent
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Abstract
A low z-average molecular weight, high softening point polystyrene resin having a narrow molecular weight distribution, as well as methods of making and using the same, are provided. The use of an inert solvent and/or the order of addition of reactants during polymerization may contribute to the unique properties of the final homopolymeric resin. The polystyrene resin can be partially or fully hydrogenated and may have particular use as a tackifying agent in a variety of hot melt adhesive and rubber compositions.
Claims14
A process for producing a polystyrene homopolymer resin, said process comprising:
- (a) combining at least a solid acid catalyst, an inert solvent, and styrene to thereby form a reaction mixture;
- and
- (b) polymerizing at least a portion of said styrene in said reaction mixture to thereby produce said polystyrene homopolymer resin having a Ring & Ball softening point of at least 85° C. and not more than 110° C., a z-average molecular weight (Mz) from about 500 dalton to about 3,000 dalton, and a polydispersity index from about 1.1 to not more than 1.7,
- wherein said inert solvent has an aromatic hydrogen content of not more than 10 percent, as measured by proton NMR;
- and
- wherein said polystyrene homopolymer resin comprises styrenic moieties having not more than 5 weight percent of end-group moieties other than styrenic moieties.
Dependencies are inferred from the claim text.