Union Camp Corporation

Kenneth E Krajca

Charles R Frihart

Robert W Johnson, Jr

Brett A Neumann

Light-colored phenolic-modified rosin esters, suitable for use as, for example, tackifiers in adhesive compositions, are prepared by reacting together rosin, a phenolic compound, formaldehyde or a reactive equivalent thereof, and a non-phenolic hydroxyl-containing organic compound in the presence of at least one lightening agent selected from phenol sulfide compounds, phosphorous acid, esters of phosphorous acid, and hypophosphite salts. The formaldehyde or reactive equivalent is present in an amount ranging from about 1.1 to about 3.5 equivalents of --CHO moieties per 1 equivalent of Ar--OH moiety of the phenolic compound, in order to obtain rosin esters having desirably low color, and adequately low molecular weight to effectively function as tackifiers.

Light-colored, low molecular weight phenolic-modified rosin esters

Improved rosin ester compositions are provided having diminished tendency toward hazing concomitant with good viscosity stability when employed in adhesive systems such as hot melt adhesive systems. Addition of zinc composition to rosin ester formulations in an effective amount serves to secure these improvements. Zinc oxide, zinc hydroxide and zinc salts of organic acids are suitable for employment with zinc resinates being preferred in accordance with the practice of certain embodiments.

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Savannah, GA, United States of America

Kenneth E Krajca