Abstract: The present invention relates to an unsaturated polyester resin comprising itaconate esters as reactive unsaturations, wherein the acid value of the resin is in the range of from 25 to 125 and the molar ratio of hydroxyl end groups and carboxylic acid end groups is in the range of from 0.33 to 3. In one embodiment, the molar ratio of hydroxyl end groups and carboxylic acid end groups is in the range of from 0.33 to 0.9. In another embodiment, the molar ratio of hydroxyl end groups and carboxylic acid end groups is in the range of from 1.1 to 3.

Abstract: The present invention relates to a resin composition comprising (a) an unsaturated polyester resin having a molecular weight Mn of at least 750 Dalton and at most 5000 Dalton and (b) a reactive diluent, wherein the unsaturated polyester resin comprises C5-C10 unsaturated diacid building blocks and isosorbide building blocks. Preferably, at least part of the isosorbide is derived from a non-fossil source. Preferably, itaconic acid or anhydride is used as the C5 unsaturated dicarboxylic acid.

Abstract: The present invention relates to an unsaturated polyester resin comprising itaconate ester units as reactive unsaturation, wherein the resin comprises itaconate, citraconate and mesaconate ester units. Preferably, the resin comprises itaconate, citraconate and mesaconate ester units in an amount of from 40 to 90 mol % itaconate, from 2 to 30 mol % citraconate and from 5 to 40 mol % mesaconate in which 100 mol % is the total amount of itaconate, citraconate and mesaconate esters units.

Abstract: The present invention relates to a resin composition comprising (a) an unsaturated polyester resin having a molecular weight Mn of at least 750 Dalton and at most 5000 Dalton and (b) a reactive diluent, wherein the unsaturated polyester resin comprises C5-C10 unsaturated diacid building blocks and isosorbide building blocks. Preferably, at least part of the isosorbide is derived from a non-fossil source. Preferably, itaconic acid or anhydride is used as the C5 unsaturated dicarboxylic acid.

Abstract: The present invention relates to an unsaturated polyester resin comprising itaconate esters as reactive unsaturations, wherein the acid value of the resin is in the range of from 25 to 125 and the molar ratio of hydroxyl end groups and carboxylic acid end groups is in the range of from 0.33 to 3. In one embodiment, the molar ratio of hydroxyl end groups and carboxylic acid end groups is in the range of from 0.33 to 0.9. In another embodiment, the molar ratio of hydroxyl end groups and carboxylic acid end groups is in the range of from 1.1 to 3.

Abstract: The present invention relates to a process for preparing an unsaturated polyester resin comprising itaconate ester units as reactive unsaturations by reacting at least itaconic acid and/or itaconic anhydride and at least one diol, wherein the process is effected in the presence of an inhibitor having a gelation activity factor less than or equal to (0.5) and having an efficiency factor of from (0.55) up to 1.

Abstract: The present invention relates to a process for preparing unsaturated polyester resin comprising itaconate ester units as reactive unsaturations, wherein the process comprises reacting at least itaconic acid and/or itaconic anhydride and at least one diol in the presence of benzoquinone and/or alkyl substituted benzoquinone, whereby the total amount of benzoquinone and alkyl substituted benzoquinone is at least 200 ppm.

Abstract: The present invention relates to an unsaturated polyester resin comprising itaconate ester units as reactive unsaturation, wherein the resin comprises itaconate, citraconate and mesaconate ester units. Preferably, the resin comprises itaconate, citraconate and mesaconate ester units in an amount of from 40 to 90 mol % itaconate, from 2 to 30 mol % citraconate and from 5 to 40 mol % mesaconate in which 100 mol % is the total amount of itaconate, citraconate and mesaconate esters units.