Substituted phenol-formaldehyde novolac resins containing reduced quantities of 2-functional components and epoxy novolac resins prepared therefrom
AssigneeThe Dow Chemical Company
InventorsJames L. Bertram, Louis L. Walker, Avis L. McCrary, Fermin M. Cortez
Life of this patent
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Abstract
The 2-functional component of substituted phenol-aldehyde novolac resins is reduced. Epoxy novolac resins prepared from the novolac resin containing reduced quantities of 2-functional product exhibit increased Tg values when cured.
Claims14
An epoxy novolac resin which results from epoxidizing with an epihalohydrin, a novolac resin which results from removing at least about 25 weight percent of the 2-functional component from a novolac resin having an average functionality greater than 2 which results from reacting (1) a material having at least one aromatic hydroxyl group per molecule selected from the group consisting of (a) a substituted phenol wherein the substituent groups are hydroxyl, hydrocarbyl or hydrocarbyloxy groups having from 1 to about 9 carbon atoms, or a halogen;
- and (b) a mixture of said substituted phenol and phenol wherein more than about 50 molar percent of the mixture is a substituted phenol;
- with (2) an aldehyde;
- said novolac resin being represented by the formula ##STR4## wherein each A is independently a divalent hydrocarbon group or a divalent hydrocarbon group substituted with any inert substituent group;
- each R is independently hydrogen, a halogen atom, a hydroxyl group or a hydrocarbon or hydrocarbyloxy group having from 1 to about 9 carbon atoms;
- and n has an average value of from 1 to about 10 with the proviso that more than 50 percent of the aromatic rings has at least one R group which is other than hydrogen.
An epoxy novolac resin which results from epoxidizing with an epihalohydrin, a novolac resin having an average functionality greater than 2 which results from reacting an aldehyde with a phenolic hydroxyl-containing material which is (a) a phenol substituted with at least one but not more than about three groups selected from hydrocarbyl, halogen or hydroxyl groups, or any combination thereof or (b) a mixture of a phenol substituted with at least one but not more than about three groups selected from hydrocarbyl, halogen or hydroxyl groups, or any combination thereof with phenol with the proviso that more than about 50 mole percent of the mixture is a substituted phenol;
- wherein said novolac resin has a ratio of 2-functional component to 3-functional component of not greater than about 0.7:1, and is represented by the formula ##STR5## wherein each A is independently a divalent hydrocarbon group or a divalent hydrocarbon group substituted with any inert substituent group;
- each R is independently hydrogen, a halogen atom, a hydroxyl group or a hydrocarbon or hydrocarbyloxy group having from 1 to about 9 carbon atoms;
- and n has an average value of from 1 to about 10 with the proviso that more than 50 percent of the aromatic rings has at least one R group which is other than hydrogen.
Dependencies are inferred from the claim text.