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US 4,052,359 AGranted
Dilutable resole resin solutions having stabilized dispersed inert salts
AssigneeMonsanto Company
InventorHarold P. Higginbottom
Life of this patent
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Abstract
This invention relates to stable water dilutable resoles. Said resoles are catalyzed with alkaline earth metal hydroxides and neutralized with oxalic acid or its acid salts providing inert insoluble oxalate salts dispersed in said resoles. Said salts are size controlled and stabilized by the presence of particular anionic type dispersing agents. A method for manufacture is disclosed.
Claims22
A stable dilutable aqueous solution of a resole resin having pH of 3 to 8.5 comprising:
- a. said resole resin having a number average molecular weight is less than about 250, a water tolerance greater than 500 percent, a combined formaldehyde to phenol ratio in the range of from about 1.0:1 to 2.9:1,
- b. a dispersion of insoluble oxalate salt particles, wherein, said resole being prepared with a catalyst comprising alkaline earth metal hydroxides selected from the group consisting of magnesium, calcium, barium strontium and mixtures thereof, said pH being adjusted with a compound selected from the group consisting of oxalic acid, ammonium oxalate and mixtures thereof providing a dispersion of insoluble oxalate salt particles of said alkaline earth metal ions in said solution, and
- c. said solution having present an anionic dispersing agent in an amount of from about 0.10 to 20 percent based on the weight of said resole resin, said dispersing agent being selected so as to prevent flocculation of said particles when water, up to the water tolerance of said resole resin is added to said solution.
A process for preparing stable dilutable aqueous resole resin solutions which comprises:
- a. reacting 1.0 mole of phenol with from about 1.0 to 3.5 moles of formaldehyde under basic conditions so as to produce a resole resin having a number average molecular weight in the range of from about 150 to 250, said basic conditions being provided by a alkaline earth hydroxide catalyst selected from the group consisting of magnesium, calcium, barium, strontium and mixtures thereof,
- b. adjusting the pH of said solution to about 3 and 8.5 with a compound selected from the group consisting of oxalic acid, ammonium oxalate and mixtures thereof in the presence of from about 0.10 to 20 percent by weight, based on said resole resin, of an anionic dispersing agent.
- c. producing a stable dispersion of insoluble particles of oxalate salts of said alkaline earth metal ions in said solution, said dispersing agent being selected to optimize the particle size of said salts and to inhibit the flocculation of said slats when water up to the water tolerance of said resole resin is added to said resole solutions.
Dependencies are inferred from the claim text.