Methods for reducing the solubility of phenolic resins using latent acids
View Patent ↗Resin compositions having a reduced solubility and methods for making and using same are provided. In at least one specific embodiment, the resin composition can include a phenolic resin, a latent acid, a catalyst, and a liquid medium. The catalyst can be a base compound and can be present in an amount of about 2 wt % to about 7 wt %, based on the combined weight of the phenolic resin, the latent acid, the catalyst, and the liquid medium.
1. A resin composition comprising: a phenolic resin, a latent acid, a catalyst, and a liquid medium, wherein the catalyst comprises a base compound and is present in an amount of about 2 wt % to about 7 wt %, based on the combined weight of the phenolic resin, the latent acid, the catalyst, and the liquid medium, wherein the phenolic resin comprises a phenolic resin catalyst and a reaction product of a phenolic monomer and an aldehyde monomer reacted in the presence of the phenolic resin catalyst, and wherein a molar ratio of the phenolic resin catalyst to the phenolic monomer is about 0.001:1 to about 1:1.
2. The resin composition of claim 1 , wherein the phenolic resin is present in an amount of about 20 wt % to about 50 wt %, the latent acid is present in an amount of about 0.3 wt % to about 10 wt %, and the liquid medium is present in an amount of about 40 wt % to about 70 wt %, based on the combined weight of the phenolic resin, the latent acid, the catalyst, and the liquid medium.
3. The resin composition of claim 1 , wherein the phenolic resin comprises a phenol formaldehyde resin having a formaldehyde to phenol molar ratio of about 1.9:1 to about 2.6:1.
4. The resin composition of claim 1 , wherein the latent acid comprises an amine salt of triethylamine and sulfuric acid.
5. The resin composition of claim 1 , wherein the latent acid comprises hydroxylamine sulfate, hydroxylamine phosphate, hydroxylamine phenol sulfonate, hydroxylamine p-toluene sulfonate, or any mixture thereof.
6. The resin composition of claim 1 , wherein the resin composition has a pH of greater than 8.
7. The resin composition of claim 1 , further comprising a plurality of lignocellulose substrates having an average moisture concentration of at least 7 wt % to about 25 wt %.
8. The resin composition of claim 1 , wherein:
the phenolic resin comprises a phenol formaldehyde resin having a formaldehyde to phenol molar ratio of about 1.9:1 to about 2.6:1,
the phenolic resin is present in an amount of about 20 wt % to about 50 wt %, the latent acid is present in an amount of about 0.3 wt % to about 10 wt %, and the liquid medium is present in an amount of about 40 wt % to about 70 wt %, based on the combined weight of the phenolic resin, the latent acid, the catalyst, and the liquid medium,
the catalyst is present in an amount of about 2 wt % to about 4 wt %, based on the combined weight of the phenolic resin, the latent acid, the catalyst, and the liquid medium,
the phenolic resin catalyst comprises an alkali metal hydroxide, an alkali earth metal hydroxide, or a mixture thereof,
the catalyst comprises sodium hydroxide,
the latent acid comprises hydroxylamine sulfate, hydroxylamine phosphate, hydroxylamine phenol sulfonate, hydroxylamine p-toluene sulfonate, or any mixture thereof, and
the resin composition has a pH of greater than 8.
9. The resin composition of claim 1 , further comprising a plurality of lignocellulose substrates having an average moisture concentration of at least 7 wt % to about 25 wt %, wherein:
the phenolic resin comprises a phenol formaldehyde resin having a formaldehyde to phenol molar ratio of about 1.9:1 to about 2.6:1,
the phenolic resin is present in an amount of about 20 wt % to about 50 wt %, the latent acid is present in an amount of about 0.3 wt % to about 10 wt %, and the liquid medium is present in an amount of about 40 wt % to about 70 wt %, based on the combined weight of the phenolic resin, the latent acid, the catalyst, and the liquid medium,
the catalyst is present in an amount of about 2 wt % to about 4 wt %, based on the combined weight of the phenolic resin, the latent acid, the catalyst, and the liquid medium,
the phenolic resin catalyst comprises sodium hydroxide,
the catalyst comprises sodium hydroxide,
the latent acid comprises hydroxylamine sulfate, hydroxylamine phosphate, hydroxylamine phenol sulfonate, hydroxylamine p-toluene sulfonate, or any mixture thereof,
the liquid medium comprises water, and
the resin composition has a pH of greater than 8.
10. A method for making a composite product, comprising:
mixing a plurality of lignocellulose substrates and a resin composition to produce a resinated furnish, wherein the resin composition comprises a phenolic resin, a latent acid, a catalyst, and a liquid medium, wherein the catalyst comprises a base compound and is present in an amount of about 2 wt % to about 7 wt %, based on the combined weight of the phenolic resin, the latent acid, the catalyst, and the liquid medium, wherein the phenolic resin comprises a phenolic resin catalyst and a reaction product of a phenolic monomer and an aldehyde monomer reacted in the presence of the phenolic resin catalyst, and wherein a molar ratio of the phenolic resin catalyst to the phenolic monomer is about 0.001:1 to about 1:1; and
heating the resinated furnish to a temperature of about 100° C. to about 300° C. to at least partially cure the resin composition and produce the composite product.
11. The method of claim 10 , wherein the phenolic resin is present in an amount of about 20 wt % to about 50 wt %, the latent acid is present in an amount of about 0.3 wt % to about 10 wt %, and the liquid medium is present in an amount of about 40 wt % to about 70%, based on the combined weight of the phenolic resin, the latent acid, the catalyst, and the liquid medium.
12. The method of claim 10 , wherein the latent acid comprises an amine salt of triethylamine and sulfuric acid.
13. The method of claim 10 , wherein the latent acid comprises hydroxylamine sulfate, hydroxylamine phosphate, hydroxylamine phenol sulfonate, hydroxylamine p-toluene sulfonate, or any mixture thereof.
14. The method of claim 10 , wherein the phenolic resin comprises a phenol formaldehyde resin having a formaldehyde to phenol molar ratio of about 1.9:1 to about 2.6:1, wherein the resin composition has a pH of greater than 8 when heated.
15. A composite product, comprising:
an at least partially cured resinated furnish, wherein, prior to curing, the resinated furnish comprises a plurality of lignocellulose substrates and a resin composition, wherein the resin composition comprises a phenolic resin, a latent acid, a catalyst, and a liquid medium, wherein the catalyst comprises a base compound and is present in an amount of about 2 wt % to about 7 wt %, based on the combined weight of the phenolic resin, the latent acid, the catalyst, and the liquid medium, wherein the phenolic resin comprises a phenolic resin catalyst and a reaction product of a phenolic monomer and an aldehyde monomer reacted in the presence of the phenolic resin catalyst, and wherein a molar ratio of the phenolic resin catalyst to the phenolic monomer is about 0.001:1 to about 1:1.
16. The composite product of claim 15 , wherein the phenolic resin is present in an amount of about 20 wt % to about 50 wt %, the latent acid is present in an amount of about 0.3 wt % to about 10 wt %, and the liquid medium is present in an amount of about 40 wt % to about 70%, based on the combined weight of the phenolic resin, the latent acid, the catalyst, and the liquid medium.
17. The composite product of claim 15 , wherein the phenolic resin comprises a phenol formaldehyde resin having a formaldehyde to phenol molar ratio of about 1.9:1 to about 2.6:1, wherein the latent acid comprises hydroxylamine sulfate, hydroxylamine phosphate, hydroxylamine phenol sulfonate, hydroxylamine p-toluene sulfonate, or any mixture thereof, and wherein the phenolic resin is at least partially cured at a pH of greater than 9.
18. The resin composition of claim 1 , wherein the phenolic resin catalyst comprises an alkali metal hydroxide, an alkali earth metal hydroxide, or a mixture thereof, and wherein the base comprises sodium hydroxide, potassium hydroxide, or a mixture thereof.
19. The resin composition of claim 1 , wherein the base comprises sodium hydroxide, and wherein the sodium hydroxide is present in amount of about 2 wt % to about 7 wt %, based on a combined weight of the phenolic resin, the latent acid, the sodium hydroxide, and the liquid medium.
20. The resin composition of claim 1 , wherein:
the phenolic resin comprises a phenol formaldehyde resin having a formaldehyde to phenol molar ratio of about 1.9:1 to about 2.6:1,
the phenolic resin is present in an amount of about 20 wt % to about 50 wt %, the latent acid is present in an amount of about 0.3 wt % to about 10 wt %, and the liquid medium is present in an amount of about 40 wt % to about 70 wt %, based on the combined weight of the phenolic resin, the latent acid, the catalyst, and the liquid medium,
the phenolic resin catalyst comprises an alkali metal hydroxide, an alkali earth metal hydroxide, or a mixture thereof,
the base comprises sodium hydroxide and the sodium hydroxide is present in amount of about 2 wt % to about 7 wt %, based on a combined weight of the phenolic resin, the latent acid, the sodium hydroxide, and the liquid medium,
the latent acid comprises hydroxylamine sulfate, hydroxylamine phosphate, hydroxylamine phenol sulfonate, hydroxylamine p-toluene sulfonate, or any mixture thereof,
the liquid medium comprises water, and
the resin composition has a pH of greater than 8.