Liquid hardening
Curing agents for air-drying alkyd-based resins, coatings, such as paint, varnish or wood stain, inks and linoleum floor coverings, based on an iron/manganese complex containing tetradentat, pentadentate or hexadentate nitrogen donor ligands are disclosed.
1. A curable liquid medium comprising:
a) from 1 to 90 wt % of an alkyd-based resin; and,
b) from 0.0001 to 0.1 wt % of a siccative, wherein the siccative is an iron or manganese complex of a tetradentate, pentadentate or hexadentate nitrogen donor ligand, wherein the ligand is:
wherein
each R 1 , R 2 independently represents —R 4 —R 5 ,
R 3 represents hydrogen, optionally substituted alkyl, aryl or arylalkyl, or —R 4 —R 5 ,
each R 4 independently represents a single bond or optionally substituted alkylene, alkenylene, oxyalkylene, aminoalkylene, alkylene ether, carboxylic ester or carboxylic amide, and
each R 5 independently represents an optionally N-substituted aminoalkyl group or an optionally substituted heteroaryl group selected from pyridinyl, pyrazinyl, pyrazolyl, pyrrolyl, imidazolyl, benzimidazolyl, pyrimidinyl, triazolyl and thiazolyl.
2. The curable liquid medium according to claim 1 , wherein the ligand is selected from the group consisting of N,N-bis(pyridin-2-yl-methyl)-bis(pyridin-2-yl)methylamine and N,N-bis(pyridin-2-yl-methyl-1,1-bis(pyridin-2-yl)-1-aminoethane.
3. The curable liquid medium according to claim 1 , wherein the iron ion is selected from Fe(II) and Fe(III) and the manganese ion is selected from Mn(II), Mn(III), and Mn(IV).
4. The curable liquid medium according to claim 1 , wherein the siccative is an iron (II) or iron (III) complex.
5. The curable liquid medium according to claim 1 , wherein the siccative is an iron (II) complex.
6. The curable liquid medium according to claim 1 , wherein the content of the siccative is between 0.0001 and 0.05% w/w.
7. The curable liquid medium according to claim 1 further comprising between 0.001% and 0.1% of at least one antioxidant selected from the group consisting of di-tert-butyl hydroxy toluene, Ethoxyquine, α-tocopherol, and 6-hydroxy-2,5,7,8-tetra-methylchroman-2-carboxylic acid.
8. The curable liquid medium according to claim 7 , wherein the composition comprises between 0.002 and 0.05% of at least one antioxidant.
9. The curable liquid medium according to claim 7 , wherein the antioxidant is α-tocopherol.
10. The curable liquid medium according to claim 1 , containing between 0.001 and 90% of ethylene glycol, diethylene glycol, dipropylene glycol, glycerol, pentaerythritol, dipenta erythritol, neopentyl glycol, trimethylol propane, trimethylol ethane, di-trimethylol propane and 1,6-hexane diol.
11. The curable liquid medium according to claim 10 , containing between 0.1 and 50% of ethyleneglycol or glycerol.
12. The curable liquid medium according to claim 10 , containing between 0.3 and 5% of ethyleneglycol or glycerol.
13. The curable liquid medium according to claim 1 , containing between 0.001 and 2.5% of lead, zirconium, bismuth, barium, vanadium, cerium, calcium, lithium, strontium, and zinc.
14. The curable liquid medium according to claim 1 when cured.