Stable aqueous novolac dispersion
View Patent ↗An aqueous composition including a particulate novolac resin and a polyol, wherein >50% of the number of total particles of novolac resin have a particle size of >15 μm and >5% of the number of total particles of novolac resin have a particle size of >50 μm, wherein the particulate novolac resin has a dropping point temperature of >127° C., and wherein the aqueous composition is essentially free of organic solvent. The aqueous composition will form a stable dispersion which is ideal for the preparation of a film or coating of substrates such as fiberglass, nonwoven fibers, or lignocellulosic materials which include composite boards, plywoods, parquets, laminated veneer lumber (LVL), laminated flooring, doors, wood for door frames and paper.
1. An aqueous composition comprising a particulate novolac resin and a polyol, wherein >50% of the number of total particles of novolac resin have a particle size of >15 μm and >5% of the number of total particles of novolac resin have a particle size of >50 μm, wherein the particulate novolac resin has a dropping point temperature of >127° C., and a polyol, wherein the aqueous composition is essentially free of organic solvent, and
wherein the novolac particles have a melt temperature of >100°.
2. The aqueous composition according to claim 1 , which is in the form of a stable dispersion.
3. The aqueous composition according to claim 2 , wherein the novolac particles have a flow distance of <45 mm and a weight average molecular weight (M w ) of >3,800 daltons.
4. The aqueous composition according to claim 1 , wherein the polyol is a carbohydrate.
5. The aqueous composition according to claim 4 , wherein the carbohydrate is a waxy starch.
6. The aqueous composition according to claim 4 , wherein the carbohydrate is a low molecular weight carbohydrate.
7. The aqueous composition according to claim 2 , wherein the polyol is in a concentration of 0.1-55 wt % based on the weight of the aqueous composition excluding the weight of the novolac.
8. The aqueous composition according to claim 2 , wherein the dispersion has a continuous phase having a density of >1.05 g/cm 3 and a DIN Cup Viscosity (using 4 mm diameter hole) of at least 10 sec.
9. The aqueous composition according to claim 1 , wherein the polyol is a carbohydrate and the aqueous composition further comprises protein.
10. A method for preparing a aqueous composition of particulate novolac resin comprising:
combining a polyol, novolac resin particles and water, in any order,
wherein >50% of the number of total particles of novolac resin have a particle size of >15 μm and >5% of the number of total particles of novolac resin have a particle size of >50 μm, wherein the particulate novolac resin has a dropping point temperature of >127° C., and wherein the aqueous composition is essentially free of organic solvent, and
wherein the novolac particles have a melt temperature of >100° C.
11. The method according to claim 10 , wherein the aqueous composition is a stable dispersion of the particulate novolac resin.
12. The method according to claim 10 , wherein the polyol is combined with water until the polyol is thoroughly mixed in the water and then adding the novolac resin particles to the mixture.
13. The method according to claim 12 , wherein the polyol is combined with water and the mixture is heated to at least 50° C.
14. The method according to claim 13 , wherein the mixture is cooled to room temperature prior to adding the novolac resin particles to the mixture.
15. The method according to claim 10 , wherein the novolac particles have a flow distance of <45 mm and a weight average molecular weight (M w ) of >3,800 daltons.
16. The method according to claim 10 , wherein the polyol is a carbohydrate.
17. The method according to claim 10 , wherein the polyol which is combined with novolac resin particles and water is added as a starch-containing product comprising protein.
18. The method according to claim 16 , wherein the carbohydrate is a waxy starch.
19. The method according to claim 16 , wherein the carbohydrate is a low molecular weight carbohydrate.
20. The method according to claim 10 , wherein the polyol is in a concentration of 0.1-55 wt % based on the weight of the aqueous composition excluding the weight of the novolac.
21. A film or coating formed by applying the aqueous composition according to claim 1 to a substrate and removing the aqueous solvent.
22. A fiberglass product prepared by applying the aqueous composition according to claim 1 to fiberglass and removing the aqueous solvent.
23. An agricultural/horticultural product prepared by applying the aqueous composition according to claim 1 to nonwoven fibers and removing the aqueous solvent.
24. A lignocellulosic product prepared by applying the aqueous composition according to claim 1 to lignocellulosic material and removing the aqueous solvent.
25. The lignocellulosic product according to claim 24 , which is a composite board, plywood, parquet, laminated veneer lumber (LVL), laminated flooring, door, wood for door frame and paper.