Aqueous dispersions of polyurethane resins based on rosin

Patent metadata

Field	Value
Publication number	US-9701778-B2
Application number	US-201314388291-A
Country	US
Kind code	B2
Filing date	Mar 27, 2013
Priority date	Mar 30, 2012
Publication date	Jul 11, 2017
Grant date	Jul 11, 2017

Abstract

The invention relates to rosin-based polyurethane resins derived from hydroxylated fatty polyesters modified with rosin, where the polyesters are bio-based, The invention also relates to aqueous dispersions of these resins, and the use of these resins in aqueous coatings.

First claim

The invention claimed is:

1. A linear or branched polyurethane resin derived from fatty polyester, wherein said polyurethane resin is derived from at least one hydroxylated fatty polyester A), and wherein:
said polyester A) is the product of reaction of a) an alcohol component with b) an acid component, which acid component b) comprises b1) at least one fatty acid, said fatty acid being chosen from the group consisting of b1.1) at least one oxidizable fatty monoacid and/or polyacid, comprising at least one oxidizable unsaturation, b1.2) at least one non-oxidizable fatty monoacid and/or polyacid, and b1.3) at least one mixture of fatty acids b1.1) and b1.2),
said component b) further comprising b2) rosin and/or rosin derivatives bearing at least one carboxylic acid function, said rosin and/or derivatives b2) representing from 30% to 85% by weight relative to the total weight of the hydroxylated fatty polyester A)
optionally, said polyester A) having a zero oil length (0%) or an oil length of between 0 and 60%,
optionally, said polyester A) having a weight ratio of oxidizable fatty acids (monoacids) b1.1) relative to the overall fatty acids b1.1)+b1.2) of 0 or greater than 0 and up to 1,

and with said resin being the product of reaction of said polyol polyester A) with:
B) at least one diol comprising an acid functional group, chosen from the group consisting of carboxylic, sulfonic, phosphonic or phosphinic, said acid functional group optionally being neutralized to salt form with a weak base, and
C) at least one polyisocyanate, of functionality from 2 to 3.

2. The resin of claim 1 , wherein said acid component b) comprises, said fatty acid b1), said rosin and/or said rosin derivatives b2), and at least one acid compound b3, with b3) having at least one carboxylic acid function and optionally with an hydroxyl function and an overall functionality of 2 to 3, with b3) being chosen from the group consisting of b3.1) saturated polyacids, b3.2) ethylenically unsaturated polyacids, and b3.3) hydroxy acids.

3. The resin as claimed in claim 1 , wherein said acid compound b1) is a non-oxidizable fatty polyacid b1.2).

4. The resin as claimed in claim 1 wherein said alcohol component a) comprises at least one polyol of functionality ranging from 2 to 10.

5. The resin as claimed in claim 4 , wherein said polyol is selected from the group consisting of: ethylene glycol, polyethylene glycol, propylene glycol, 1,3-propanediol, dipropylene glycol, triethylene glycol, glycerol, diglycerol, trimethylolpropane, trimethylolethane, pentaerythritol, dipentaerythritol, sorbitol, mannitol, methyl glucoside, and polyglycerol.

6. The resin as claimed in claim 1 wherein said polyester A) has an acid number of less than 10, an OH number of greater than 25, and a calculated number-average molecular weight Mn ranging from 250 to 10 000 (g/mol).

7. The resin as claimed in claim 1 wherein said oxidizable fatty acid b1.1) is selected from fatty monoacids of plant or animal origin, with a mean iodine number from 100 to 200 mg I 2 /g.

8. The resin as claimed in claim 1 wherein said polyacid b1.2) comprises at least one C 36 fatty acid dimer and/or a C 54 fatty acid trimer and wherein said alcohol component a) comprises glycerol or at least one glycerol oligomer and/or pentaerythritol and/or dipentaerythritol.

9. The resin as claimed in claim 1 wherein said acid function of said diol B) is in a form neutralized (salified) with a weak base selected from the group consisting of tertiary amines and phosphines.

10. The resin as claimed in claim 1 comprising hydroxyl reactive groups.

11. An organic binder composition comprising at least one resin as defined according to claim 1 .

12. The composition as claimed in claim 11 , further comprising at least a second resin different from the first, this second resin being selected from the group consisting of resins of polyesters based on fatty acids.

13. An aqueous resin dispersion, comprising at least one polyurethane resin of claim 1 .

14. The dispersion as claimed in claim 13 , having a solids content ranging from 20% to 60% and a mean particle size ranging from 30 to 200 nm.

15. The dispersion as claimed in claim 13 that is free of organic solvent with a corresponding VOC content of less than 5000 ppm.

16. An aqueous resin dispersion comprising a mixture of at least a first aqueous resin dispersion of claim 13 and at least a second resin dispersion different from the first, the second resin dispersion being selected from the group consisting of alkyd resin dispersions, acrylic dispersions, acrylic emulsions, styrene-acrylic emulsions, polyurethane dispersions, polyester dispersions.

17. The dispersion as claimed in claim 16 , wherein the weight content of said first dispersion is from 50% to 99.5% relative to said mixture.

18. The aqueous dispersion as claimed in claim 13 wherein said resin comprises hydroxyl reactive groups.

19. A process for preparing a resin according to claim 1 in the form of an aqueous dispersion, comprising the following successive steps:
i) preparing a polyol polyester A) as defined in claim 1 , by bulk polycondensation reaction in the melt of said alcohol a) and acid b) components, until an acid number of less than 10 is obtained,
ii) dissolution and dilution of said polyester in a volatile solvent with a boiling point of less than 150° C.,
iii) polyaddition reaction in solvent medium of said polyester A) as obtained in step ii) by addition of said diol B) and of said polyisocyanate, with partial or total neutralization of said acid function of B) with a weak base chosen from the group consisting of amines and phosphines,
iv) at the end of the reaction of step iii), dispersion in water with stirring of the polyurethane solution as obtained in step iii), before
v) removal of said organic solvent by evaporation or by steam-stripping or by an inert gas stripping.

Assignees

• Arkema France

Inventors

• Herve Gregoire
• Cogordan Frank

Classifications

• C08G18/686 Primary

  containing cycloaliphatic groups · CPC title

• C08G18/4288

  modified by higher fatty oils or their acids or by resin acids · CPC title

• C09D5/022

  Emulsions, e.g. oil in water · CPC title

• C09D175/06

  from polyesters · CPC title

• C08G18/755 Primary

  and at least one isocyanate or isothiocyanate group linked to a secondary carbon atom of the cycloaliphatic ring, e.g. isophorone diisocyanate · CPC title