Bio-based thermosets

Patent metadata

Field	Value
Publication number	US-10730998-B2
Application number	US-201615758181-A
Country	US
Kind code	B2
Filing date	Sep 15, 2016
Priority date	Sep 15, 2015
Publication date	Aug 4, 2020
Grant date	Aug 4, 2020

Abstract

The invention relates to novel curable bio-based thermosetting compositions of a) at least one highly-functional bio-based epoxy resin; and b) at least one carboxylic acid crosslinker selected from the group consisting of a water-soluble multifunctional carboxylic acid, a dicarboxylic acid oligomer from a melt reaction between a diol and a dicarboxylic acid or its anhydride, and mixtures thereof and which are curable with water, an alcohol or a water and alcohol mixture. The bio-based thermosets of the invention may be free of VOCs and/or organic solvents. The bio-based thermosets of the invention can be used to form coatings, composites, adhesives, and films. Methods of making the bio-based thermosets of the invention are disclosed as are coating compositions and coated objects, such as coatings, composites, adhesives, and films, using the bio-based thermosets of the invention.

First claim

The claimed invention is:

1. A curable bio-based thermosetting composition comprising a solution of: a pre-reaction product of a) at least one highly-functional bio-based epoxy resin and b) at least one carboxylic acid crosslinker; and a solvent selected from the group consisting of water, a C 1 -C 3 alcohol, and mixtures thereof;
wherein the a) at least one highly-functional bio-based epoxy resin is the reaction product of: a polyol having 4 or more hydroxyl groups, an ethylenically unsaturated fatty acid, and an optional saturated fatty acid, wherein at least one ethylenically unsaturated group of the ethylenically unsaturated fatty acid is oxidized to an epoxy group;
wherein the b) at least one carboxylic acid crosslinker is selected from the group consisting of a water-soluble multifunctional carboxylic acid, an anhydride of said water-soluble multifunctional carboxylic acid, a dicarboxylic acid oligomer from a melt reaction between a diol and a dicarboxylic acid or the anhydride of said dicarboxylic acid, and mixtures thereof;
wherein the pre-reaction product of a) and b) is formed by reacting a) and b) at a first temperature in the presence of the solvent, yielding the solution; and
wherein the curable bio-based thermosetting composition is thermally curable by continuing the reaction of the pre-reaction product in the solution at a second temperature, not less than the first temperature, to form a fully cured composition.

2. The curable bio-based thermosetting composition of claim 1 , wherein:
a) the polyol having 4 or more hydroxyl groups is selected from pentaerithritol, di-trimethylolpropane, di-pentaerithritol, tri-pentaerithritol, sucrose, glucose, mannose, fructose, galactose, raffinose, copolymers of styrene and allyl alcohol, polyglycidol, and poly(dimethylpropionic acid); and
b) the ethylenically unsaturated fatty acid and the optional saturated fatty acid are a vegetable or seed oil.

3. The curable bio-based thermosetting composition of claim 2 , wherein:
a) the polyol having 4 or more hydroxyl groups is sucrose; and
b) the vegetable or seed oil is selected from corn oil, castor oil, soybean oil, safflower oil, sunflower oil, linseed oil, tall oil fatty acid, tung oil, vernonia oil, and mixtures thereof.

4. The curable bio-based thermosetting composition of claim 1 , wherein the at least one highly-functional bio-based epoxy resin is selected from an epoxidized sucrose ester resin.

5. The curable bio-based thermosetting composition of claim 4 , wherein the epoxidized sucrose ester resin is epoxidized sucrose soyate.

6. The curable bio-based thermosetting composition of claim 1 , wherein the at least one carboxylic acid crosslinker is a water-soluble multifunctional carboxylic acid selected from the group consisting of citric acid, malic acid, tartaric acid, oxalic acid, malonic acid, glutaric acid, succinic acid, maleic acid (cis-butenedioic acid), fumaric acid (trans-butenedioic acid), glutamic acid, itaconic acid, citraconic acid, mesaconic acid, aspartic acid, oxalacetic acid, adipic acid, pimelic acid, azelaic acid, suberic acid, 1,2,3-propanetricarboxylic acid, cis-aconitic acid, trans-aconitic acid, isocitric acid lactone, (+)-garcinia acid, 4,4′-phosphinicobis(butane-1,3-dicarboxylic acid), chelidamic acid, chelidonic acid, trans-β-hydromuconic acid, trans-1,2-cyclohexanedicarboxylic acid, oxirane-2,3-dicarboxylic acid, 2,3-pyridinedicarboxylic acid, 2,4-pyridinedicarboxylic acid, 2,5-pyridinedicarboxylic acid, phenylmalonic acid, homophthalic acid, sebacic acid, 1,11-undecanedicarboxylic acid, dodecanedioic acid, hexadecanedioic acid, phthalic acid, isophthalic acid, terephthalic acid, trimesic acid, 1,2,4-benzenetricarboxylic acid, 2,5-furandicarboxylic acid, and mixtures thereof.

7. The curable bio-based thermosetting composition of claim 6 , wherein the water-soluble multifunctional carboxylic acid is selected from the group consisting of citric acid, malonic acid, tartaric acid, malic acid, oxalic acid, glutaric acid, and mixtures thereof.

8. The curable bio-based thermosetting composition of claim 1 , wherein the at least one carboxylic acid crosslinker is a dicarboxylic acid oligomer from a melt reaction between a diol and a dicarboxylic acid or the anhydride of said dicarboxylic acid.

9. The curable bio-based thermosetting composition of claim 8 , wherein:
the diol is selected from the group consisting of diethyleneglycol (DEG), 2-butyl-2-ethyl-1,3-propane diol (BEPD), ethylene glycol, 1,2-propane diol, 1,3-propane diol, 2-methyl-1,3-propane diol, 1,4-butanediol, 2,3-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,4-cyclohexanedimethanol, 1,3-cyclohexanedimethanol, neopentyl glycol (NPG), a 1,4:3,6 dianhydrohextol and mixtures thereof; and
the dicarboxylic acid is selected from the group consisting of oxalic acid, maleic acid, malonic acid, succinic acid, oleic acid, glutaric acid, adipic acid, pimelic acid, phthalic acid, acid anhydrides thereof.

10. The curable bio-based thermosetting composition of claim 8 , wherein:
the diol is selected from the group consisting of diethyleneglycol (DEG), ethylene glycol, 1,3-propane diol, isosorbide and mixtures thereof; and
the dicarboxylic acid is maleic acid or maleic acid anhydride.

11. The curable bio-based thermosetting composition of claim 10 , wherein the diol is isosorbide.

12. The curable bio-based thermosetting composition of claim 8 , wherein the molar ratio of carboxylic acid to hydroxyl groups, prior to the melt reaction, is 2:1.

13. The curable bio-based thermosetting composition of claim 1 , wherein the curable composition is substantially free of organic solvents.

14. The curable bio-based thermosetting composition of claim 1 , wherein the chemical equivalent ratio of epoxy to carboxylic acid, prior to the reaction of the pre-reaction product, ranges from about 1:0.1 to about 1:1.3.

15. The curable bio-based thermosetting composition of claim 1 , wherein the chemical equivalent ratio of epoxy to carboxylic acid, prior to the reaction of the pre-reaction product, ranges from about 1:0.5 to about 1:1.1.

16. The curable bio-based thermosetting composition of claim 1 , wherein the first temperature is 40° C. and the second temperature is 40° C. or higher.

17. An object coated with the curable, bio-based thermosetting composition of claim 1 .

18. A cured bio-based thermoset resin synthesized from the curable bio-based thermosetting composition of claim 1 , wherein the composition is thermally cured by continuing the reaction of the pre-reaction product in the solution at a second temperature, not less than the first temperature, to form a fully cured composition.

19. A method for producing a cured bio-based thermoset resin from the curable bio-based thermosetting composition of claim 1 comprising: continuing the reaction of the pre-reaction product in the solution by thermally curing at a second temperature, not less than the first temperature, to form a fully cured composition.

Assignees

• Ndsu Res Foundation

Inventors

• Webster Dean C
• Ma Songqi

Classifications

• C08G59/42 Primary

  Polycarboxylic acids; Anhydrides, halides or low molecular weight esters thereof · CPC title

• C08G59/04

  of polyhydroxy compounds with epihalohydrins or precursors thereof · CPC title

• C08G59/4207

  aliphatic · CPC title

• C08G65/2615

  the other compounds containing carboxylic acid, ester or anhydride groups · CPC title

• C08G59/3236 Primary

  Heterocylic compounds · CPC title