Light colored, aromatic-modified piperylene resins
AssigneeHercules Incorporated
InventorsSung G. Chu, Norman E. Daughenbaugh, Jr., Mark J. Rosner
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Abstract
A tackifier resin is prepared by polymerizing a monomer mixture of 10-70% piperylene concentrate and 30-90% of a vinyl aromatic monomer in the presence of a boron trifluoride catalyst and an inert diluent. The resin is water white in color, has a Gardner number of less than one, a softening point of 60.degree. to 120.degree. C. and a polydispersity of 1 to 5. The tackifier is used in formulations based on EVA, block copolymers and polyolefins for hot melt and pressure sensitive adhesive applications.
Claims2
A method of preparing a composition that is water white in color, has a Gardner number of less than one with excellent color stability under heat, a softening point of from about 60.degree. to about 120.degree. C., a weight average molecular weight (M.sub.w) of from about 2,000 to about 8,000, a Z average molecular weight (M.sub.z) of from about 5,000 to about 12,000, and a molecular weight distribution (M.sub.w /M.sub.n) of about 1 to about 5, comprising
- (1) polymerizing at a temperature of -10.degree. to 60.degree. C. a mixture consisting essentially of
- i) 10 to 60% by weight of a piperylene concentrate having a boiling point of 30.degree. to 50.degree. C. produced from the cracking of petroleum oil in a gasoline manufacturing process and having a 2-methyl-2-butene content of less than 5%, and
- ii) 40 to 90% by weight of a vinyl aromatic monomer,
- in the presence of 30 to 70% by weight of an inert diluent and a sufficient amount of BF.sub.3 to catalyze the reaction, and
- (2) removing the diluent and catalyst from the reaction mass to produce a final product in a yield of at least 55%.
Dependencies are inferred from the claim text.