Vegetable oil-based pressure sensitive adhesives
A pressure sensitive adhesive construct comprising: (a) a backing substrate; and (b) a pressure sensitive adhesive composition disposed on the backing substrate, wherein the pressure sensitive adhesive includes a product made from at least one epoxidized vegetable oil and at least one dibasic acid or anhydride, or a combination of a dibasic acid or anhydride and a monobasic acid or anhydride.
1. A pressure sensitive adhesive composition made by a method comprising:
initially reacting an epoxidized vegetable oil with at least one dibasic acid or anhydride thereof to produce a prepolymer product, wherein the amount of dibasic acid or anhydride reacted with the epoxidized vegetable oil is sufficient to provide a 5 to 80 mol % excess of carboxylic acid groups over that required to esterify all the epoxy groups present in the at least one epoxidized vegetable oil; and
further reacting the prepolymer product to produce the pressure sensitive adhesive composition.
2. The composition of claim 1 , wherein the epoxidized vegetable oil is epoxidized soybean oil.
3. The composition of claim 2 , wherein the dibasic acid or anhydride is selected from malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, brassylic acid, succinic anhydride, or a mixture thereof.
4. The composition of claim 2 , wherein the dibasic acid or anhydride is an aliphatic saturated carboxylic dibasic acid or anhydride.
5. The composition of claim 1 , wherein the dibasic acid or anhydride is a dicarboxylic acid or anhydride thereof.
6. The composition of claim 1 , wherein the dibasic acid or anhydride is selected from malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, brassylic acid, succinic anhydride, or a mixture thereof.
7. The composition of claim 1 , wherein the vegetable oil and dibasic acid or anhydride are all from renewable sources.
8. The composition of claim 1 , wherein the epoxidized vegetable oil has an epoxy number of 2 to 5.
9. The composition of claim 1 , wherein the dibasic acid or anhydride is an aliphatic saturated carboxylic dibasic acid or anhydride.
10. The composition of claim 1 , wherein initially reacting the epoxidized vegetable oil with at least one dibasic acid or anhydride thereof comprises heating a mixture of the epoxidized vegetable oil and at least one dibasic acid or anhydride at a temperature of 80 to 300° C.
11. The composition of claim 1 , wherein the further reacting of the prepolymer product comprises heating the prepolymer product at a temperature of 100 to 300° C.