The disclosure relates to a light color or a low color rosin or a rosin ester composition. The rosin ester comprises a reaction product of one or more rosins, one or more polyhydric alcohols, and optionally one or more monocarboxylic acids, and optionally one or more polycarboxylic acids having from 2 to 54 carbon atoms; from 0 ppm to 200 ppm of a co-catalyst, and optionally, a disproportionation catalyst, an esterification catalyst, or combinations thereof. The co-catalyst has a triplet formation quantum yield (.sub.T) of greater than 0.5 and a triplet lifetime (.sub.T) of greater than 0.5 microseconds. Methods to prepare the rosin ester compositions and uses of the compositions are also disclosed.

A three-step method to prepare a light-colored rosin ester is disclosed wherein at least in one of the steps (a) and (c) a co-catalyst is applied and wherein at least in one of the steps (a) and (c) a disproportionation catalyst is applied. In the second step, a distilled rosin is obtained which is esterified with a polyol into a light-colored rosin ester. In one embodiment, the co-catalyst has a triplet formation quantum yield (.sub.T) of greater than 0.5 and a triplet lifetime (.sub.T) of greater than 0.5 microseconds. In another embodiment, the co-catalyst is selected from acridone, anthrone, 9-fluorenone, thioxanthone, xanthone, derivatives and combinations thereof.

A three-step method to prepare a light-colored rosin ester is disclosed wherein at least in one of the steps (a) and (c) a co-catalyst is applied and wherein at least in one of the steps (a) and (c) a disproportionation catalyst is applied. In the second step, a distilled rosin is obtained which is esterified with a polyol into a light-colored rosin ester. In one embodiment, the co-catalyst has a triplet formation quantum yield (.sub.T) of greater than 0.5 and a triplet lifetime (.sub.T) of greater than 0.5 microseconds. In another embodiment, the co-catalyst is selected from acridone, anthrone, 9-fluorenone, thioxanthone, xanthone, derivatives and combinations thereof.

Presently described are methods for performing rosin purification. The methods described herein utilize a unique solvent precipitation process that surprisingly and unexpectedly reduces the color of rosin and the sulfur and unsaponifiable contents in the rosin. The described methods are also applicable to rosin derivatives such as rosin esters and amides. Utilizing this purified rosin as raw material, rosin derivatives with much improved characteristics (color, softening point and sulfur content) can be made that would otherwise be difficult to make.

Presently described are methods for performing rosin purification. The methods described herein utilize a unique solvent precipitation process that surprisingly and unexpectedly reduces the color of rosin and the sulfur and unsaponifiable contents in the rosin. The described methods are also applicable to rosin derivatives such as rosin esters and amides. Utilizing this purified rosin as raw material, rosin derivatives with much improved characteristics (color, softening point and sulfur content) can be made that would otherwise be difficult to make.

Method for the separation of at least one isoprenic constituent from the resin of a plant of guayule and/or of the guayule type comprising the steps of: a) providing a defatted resin of guayule and/or of the guayule type; b) subjecting the defatted resin to partitioning of the liquid-liquid type with solvents that are immiscible in each other thus obtaining an apolar extract containing the isoprenic constituents guayulin A, guayulin B and argentatin B; and a polar extract containing the isoprene constituents argentatin A, argentatin C and argentatin D; and c) separating at least one isoprenic constituent from said polar extract and/or from the apolar extract thus obtained, wherein step c) comprises a step in which the polar extract is subjected to partitioning of the liquid-liquid type with solvents immiscible in each other and/or a step in which the apolar extract is subjected to partitioning of the solid-liquid type.

Method for the separation of at least one isoprenic constituent from the resin of a plant of guayule and/or of the guayule type comprising the steps of: a) providing a defatted resin of guayule and/or of the guayule type; b) subjecting the defatted resin to partitioning of the liquid-liquid type with solvents that are immiscible in each other thus obtaining an apolar extract containing the isoprenic constituents guayulin A, guayulin B and argentatin B; and a polar extract containing the isoprene constituents argentatin A, argentatin C and argentatin D; and c) separating at least one isoprenic constituent from said polar extract and/or from the apolar extract thus obtained, wherein step c) comprises a step in which the polar extract is subjected to partitioning of the liquid-liquid type with solvents immiscible in each other and/or a step in which the apolar extract is subjected to partitioning of the solid-liquid type.

Disclosed are compositions which include an ethylene polymer derived from at least one polar monomer with one or more ester groups, and a rosin ester. The rosin ester can have a low hydroxyl number (e.g., a hydroxyl number seven or less), a low acid number (e.g., an acid number of ten or less), a relatively low PAN number (e.g., a PAN number less than twenty-five), a relatively high third moment or third power average molecular weight (M.sub.z), (e.g., an M.sub.z value in between 2500 and 12000 g/mol), a low sulfur content (e.g., a sulfur content lower than 600 ppm prior to antioxidant addition) or combinations thereof. The compositions can exhibit a high heat stress resistance (e.g., a heat stress pass temperature value higher than 52 C. or in between 48 C. and 60 C.) and/or improved viscosity stability and/or color stability upon thermal aging and/or improved compatibility.

Disclosed are compositions which include an ethylene polymer derived from at least one polar monomer with one or more ester groups, and a rosin ester. The rosin ester can have a low hydroxyl number (e.g., a hydroxyl number seven or less), a low acid number (e.g., an acid number of ten or less), a relatively low PAN number (e.g., a PAN number less than twenty-five), a relatively high third moment or third power average molecular weight (M.sub.z), (e.g., an M.sub.z value in between 2500 and 12000 g/mol), a low sulfur content (e.g., a sulfur content lower than 600 ppm prior to antioxidant addition) or combinations thereof. The compositions can exhibit a high heat stress resistance (e.g., a heat stress pass temperature value higher than 52 C. or in between 48 C. and 60 C.) and/or improved viscosity stability and/or color stability upon thermal aging and/or improved compatibility.

An oligoester composition is disclosed, which is a reaction product of a reactant mixture comprising one or more rosins selected from the group consisting of tall oil rosin and gum rosin; at least 15% by weight of one or more monocarboxylic acids comprising 6-36 carbon atoms; and one or more polyhydric alcohols comprising 2-36 carbon atoms, wherein each hydroxyl group of the polyhydric alcohol is separated from the other hydroxyl groups by at least 2 carbon atoms. A method for preparing an oligoester composition is also provided. Also disclosed is an oligoester composition which is an esterification reaction product of one or more rosins, one or more monocarboxylic acids, one or more polyhydric alcohols, and optionally one or more polycarboxylic acids. The composition has a weight average molecular weight of from 500 g/mol to 8,000 g/mol and a T.sub.g of between 80 C. and 100 C.