Thermosetting phenolic resin composition

A method of making a resin composition consisting essentially of reacting phenol with formaldehyde to form a phenolic resole resin, neutralizing the resin, adding a nitrogen-containing acidic phosphorus latent curing agent containing one or more moieties of the following formula:

• ##STR27## where R is selected from a C.sub.1 to C.sub.6 alkylene radical, a C.sub.3 to C.sub.7 cycloalkylene radical, an arylene radical and a divalent radical of the formula:
• ##STR28## where x and z are integers of 1 to 6, and y is an integer from 0 to 2 and wherein the divalent radical is bonded to the phosphorous atom of said moieties through the terminal oxygen atom of said radical, and adding a strong acid catalyst wherein the nitrogen-containing acidic phosphorus latent curing agent is added in a sufficient amount relative to the strong acid catalyst to retard the curing of the resin in the presence of the strong acid curing catalyst.

A method of making a reinforced resin composite consisting essentially of (1) impregnating a substrate with a resin composition comprising a mixture of (a) a phenolic resole resin, (b) a strong acid curing catalyst, and (c) a nitrogen-containing acidic phosphorus latent curing agent containing one or more moieties of the following formula:

• ##STR29## where R is selected from a C.sub.1 to C.sub.6 alkylene radical, a C.sub.3 to C.sub.7 cycloalkylene radical, an arylene radical and a divalent radical of the formula:
• ##STR30## where x and z are integers of 1 to 6, and y is an integer from 0 to 2 and wherein the divalent radical is bonded to the phosphorous atom of said moieties through the terminal oxygen atom of said radical, wherein the nitrogen-containing acidic phosphorus latent curing agent is present in the resin composition in a sufficient amount relative to the strong acid catalyst to retard the curing of the resin in the presence of the strong acid catalyst and (2) curing the resin impregnated substrate.

A reinforced resin composite prepared by (1) impregnating a substrate with a resin composition consisting essentially of a mixture of (a) a phenolic resole resin, (b) a strong acid curing catalyst, and (c) a nitrogen-containing acidic phosphorus latent curing agent containing one or more moieties of the following formula:

• ##STR31## where R is selected from a C.sub.1 to C.sub.6 alkylene radical, a C.sub.3 to C.sub.7 cycloalkylene radical, an arylene radical and a divalent radical of the formula:
• ##STR32## where x and z are integers of 1 to 6, and y is an integer from 0 to 2 and wherein the divalent radical is bonded to the phosphorous atom of said moieties through the terminal oxygen atom of said radical, wherein the nitrogen-containing acidic phosphorus latent curing agent is present in the resin composition in a sufficient amount relative to the strong acid catalyst to retard the curing of the resin in the presence of the strong acid catalyst and (2) curing the resin impregnated substrate.

A resin composition capable of being thermally cured consisting essentially of a mixture of (a) a neutralized phenolic resole resin, and (b) a nitrogen-containing acidic phosphorus latent curing agent containing one or more moieties of the following formula:

• ##STR33## where R is selected from a C.sub.1 to C.sub.6 alkylene radical, a C.sub.3 to C.sub.7 cycloalkylene radical, an arylene radical and a divalent radical of the formula:
• ##STR34## where x and z are integers of 1 to 6, and y is an integer from 0 to 2 and wherein the divalent radical is bonded to the phosphorous atom of said moieties through the terminal oxygen atom of said radical.