High ortho etherified resole resins
AssigneeMonsanto Company
InventorHarry M. Culbertson
Life of this patent
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Abstract
This invention relates to high ortho etherified resole resins. The resole resins are prepared by reacting under acidic conditions phenol with formaldehyde in the presence of a divalent electropositive metal. The resole resins are then etherified with an alcohol and dehydrated to less than 1 percent water. The novel high ortho etherified resole resins are useful in coating, bonding and adhesive compositions. Such resoles are readily curable with coreactive resins providing chemical and solvent resistance.
Claims21
A high ortho etherified phenol-formaldehyde resole resin being characterized by:
- A. having a reacted formaldehyde to phenol mol ratio of 1.10 to 2.0, said formaldehyde reacting with said phenol, forming methylol groups taking a final orientation of about 90% to 100% in the ortho position,
- B. having said phenol selected from the group consisting of phenol, meta-substituted phenols and mixtures of phenol and substituted phenols,
- C. having condensed phenol-aldehyde linkages wherein 25 to 90% of said linkages are benzyl ether linkages having a final orientation essentially in the ortho position and 10 to 75% are methylene linkages taking a final orientation of about 70 to 90% in the ortho position and about 10 to 30% in the para position,
- D. having an average degree of polymerization of less than 4.0, and
- E. having said methylol groups partially etherified with monohydric alcohols.
An improved process for preparing an etherified high ortho resole resin, said resin being characterized by:
- A. having a reacted formaldehyde to phenol mol ratio of 1.10 to 2.0, said formaldehyde reacting with said phenol, forming methylol groups taking a final orientation of about 90% to 100% in the ortho position,
- B. having said phenol selected from the group consisting of phenol, meta-substituted phenols and mixtures of phenol and substituted phenols,
- C. having condensed phenol-aldehyde linkages wherein 25 to 90% of said linkages are benzyl ether linkages having a final orientation essentially in the ortho position and 10 to 75% are methylene linkages taking a final orientation of about 70 to 90% in the ortho position and about 10 to 30% in the para position,
- D. having an average degree of polymerization of less than 4.0, and
- E. having said methylol groups partially etherified with monohydric alcohols, said etherified resoles being prepared by first reacting said phenol and said formaldehyde in an aqueous reaction mixture under reflux at about 80.degree. C. to 100.degree. C., in the presence of a divalent electropositive metal ion, while maintaining the pH in the range of about 4 to 7, wherein said pH is controlled by having a sufficient amount of an organic acid present, forming said resole in said reaction mixture, the improvement comprising, etherifying said resole with a monohydric alcohol at a temperature of 65.degree. to 100.degree. C. in said reaction mixture and dehydrating the resultant aqueous reaction mixture to a water content of less than about 1 weight percent and an alcohol content of less than about 5% by weight providing an etherified high ortho resole resin as a single phase clear liquid varnish.
Dependencies are inferred from the claim text.