Phenol-formaldehyde resin having low concentration of tetradimer
AssigneeGeorgia-Pacific Chemicals LLC
InventorsRamji Srinivasan, Kim Tutin, James Knight, Paul Baxter
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Abstract
A phenol-formaldehyde resin, having a low concentration of tetradimer, making the resin suitable for preparing a binder composition for making non-woven fiber products, such as fiberglass insulation, prepared by reacting phenol and formaldehyde in the presence of a sulfite source.
Claims29
A method of making a phenol-formaldehyde resin suitable for use in preparing a binder composition where a molar excess of formaldehyde (F) is reacted with a phenol component (P), the method comprising reacting formaldehyde (F) with the phenol component (P) under an alkaline condition in the presence of a sulfite source, the sulfite source being present in an amount to provide 0.02 to 0.6 mole sulfite per mole of phenol and wherein a first portion of formaldehyde, sufficient to establish a molar ratio of formaldehyde to phenol component of above about 0.8:1 but less than a molar excess of formaldehyde, is reacted with phenol in the presence of the sulfite source and then a second portion of formaldehyde is added to establish the molar excess of formaldehyde for further reaction.
An extended phenol-formaldehyde resin prepared by mixing a phenol-formaldehyde resin with an extender selected from the group consisting of (1) urea, (2) a mixture of urea and ammonia, (3) a cyclic urea-formaldehyde prepolymer and (4) mixtures thereof, followed by reacting the extender with the phenol-formaldehyde resin, wherein the phenol-formaldehyde resin has been prepared by reacting a molar excess of formaldehyde (F) with a phenol component under an alkaline condition in the presence of a sulfite source, the sulfite source being present in an amount to provide 0.02 to 0.6 mole sulfite per mole of phenol.
Dependencies are inferred from the claim text.