Cure accelerator system for phenolic resins
View Patent ↗The cure rate of phenol-aldehyde resins is accelerated by conjoint use of a cyclic carbonate cure accelerant and an amine cure accelerant. The cure rate is accelerated still further by addition of a resorcinol source to resin comprising a cyclic carbonate and an amine cure accelerator. Also, cured resins made in accordance with the method.
1. A curable resin composition for binding wood and wood fiber products, said composition comprising:
a curable phenol-aldehyde resin selected from the group consisting of resole resins and novolac resins comprising a source of free aldehyde;
an effective amount of cyclic carbonate cure accelerant; and
an effective amount of amine cure accelerant selected from the group consisting of polyalkylene polyamines, polyalkylene glycol polyamines, and blends thereof.
2. The composition of claim 1 wherein the cyclic carbonate cure accelerant is selected from the group consisting of alkylene carbonate, ethylene glycol carbonate; glycerol carbonate; glycidol carbonate; 1,2-butanediol carbonate; 1,3-butanediol carbonate; 1,2-pentanediol carbonate; 1,3-pentanediol carbonate; epoxy carbonates; and blends thereof, and is present in an amount between about 0.1 and about 20 weight %, based on the weight of the resin.
3. The resin composition of claim 1 wherein the polyalkylene polyamine amine cure accelerant is selected from the group consisting of triethylene triamine, triethylene tetramine, tetraethylene tetramine, tetraethylene pentamine, and blends thereof, the polyalkylene glycol polyamine amine cure accelerant is selected from the group consisting of polyethyleneglycol diamines, and blends thereof, and is present in an amount between 0.1 and about 10 weight %, based on the weight of the resin.
4. The resin composition of claim 2 wherein the polyalkylene polyamine amine cure accelerant is selected from the group consisting of triethylene triamine, triethylene tetramine, tetraethylene tetramine, tetraethylene pentamine, and blends thereof, the polyalkylene glycol polyamine amine cure accelerant is selected from the group consisting of polyethyleneglycol diamines, and blends thereof, and is present in an amount between 0.1 and about 10 weight %, based on the weight of the resin.
5. The resin composition of claim 4 further comprising an effective amount of resorcinol source.
6. The resin composition of claim 5 wherein the resorcinol source is a formaldehyde-starved novolac resorcinol-formaldehyde resin and is present in an amount sufficient to provide resorcinol in an amount between about 0.1 and about 30 weight %, based on the weight of the resin.
7. A cured phenol-aldehyde resin for binding wood and wood fiber products, said resin selected from the group consisting of resole resins and novolac resins comprising a source of free aldehyde, wherein said resin is cured in the presence of effective amounts of cyclic carbonate cure accelerant and amine cure accelerant selected from the group consisting of polyalkylene polyamines, polyalkylene glycol polyamines, and blends thereof.
8. The resin of claim 7 wherein the cyclic carbonate cure accelerant is selected from the group consisting of alkylene carbonate, ethylene glycol carbonate; glycerol carbonate; glycidol carbonate; 1,2-butanediol carbonate; 1,3-butanediol carbonate; 1,2-pentanediol carbonate; 1,3-pentanediol carbonate; epoxy carbonates; and blends thereof, and is present in an amount between about 0.1 and about 20 weight %, based on the weight of the resin.
9. The resin of claim 7 wherein the polyalkylene polyamine amine cure accelerant is selected from the group consisting of triethylene triamine, triethylene tetramine, tetraethylene tetramine, tetraethylene pentamine, and blends thereof, the polyalkylene glycol polyamine amine cure accelerant is selected from the group consisting of polyethyleneglycol diamines, and blends thereof, and is present in an amount between 0.1 and about 10 weight %, based on the weight of the resin.
10. The resin of claim 8 wherein the polyalkylene polyamine amine cure accelerant is selected from the group consisting of triethylene triamine, triethylene tetramine, tetraethylene tetramine, tetraethylene pentamine, and blends thereof, the polyalkylene glycol polyamine amine cure accelerant is selected from the group consisting of polyethyleneglycol diamines, and blends thereof, and is present in an amount between 0.1 and about 10 weight %, based on the weight of the resin.
11. The resin of claim 7 wherein said resin is cured in the presence of effective amounts of cyclic carbonate cure accelerant, amine cure accelerant, and resorcinol source.