Method for retarding ambient temperature hardening of a phenolic resin composition

A method for retarding the ambient temperature hardening of a mixture of a phenolic resole resin and magnesia aggregate which comprises mixing:

• A. magnesia aggregate;
• B. a hardenable phenolic resole resin solution having a pH of 4.5 to 9.5, a viscosity of from about 100 to 10,000 cps at 25.degree. C., a water content of about 3% to 15% by weight, said resole being in a quantity sufficient to bind the magnesia on hardening;
• and
• C. a retarder compound in an amount sufficient to retard the ambient temperature hardening of said mixture, said retarder being a compound selected from the group consisting of:
• a compound which provides an aspartate, bifluoride, citrate, fluoride, malate, tartrate, or phosphonate anion to the mixture;
• or
• a tetraalkoxy silane having from 1 to 3 carbon atoms in each alkoxy group, a partially hydrolyzed tetraalkoxy silane having from 1 to 3 carbon atoms in each alkoxy group;
• and mixtures of the foregoing retarders.

A binder-aggregate composition comprising a wet mixture of:

• A. magnesia aggregate;
• B. a curable phenolic resin solution selected from the group consisting of a novolac, a resole having a pH of about 4.5 to 9.5 and a viscosity of about 100 to 10,000 cps at 25.degree. C., and mixtures thereof, the quantity of said resin being from about 3% to 15% by weight of the magnesia;
• and
• C. a retarder compound in an amount sufficient to retard the room temperature hardening of said mixture, said retarder being a compound selected from the group consisting of:
• a compound which provides an aspartate, bifluoride, citrate, fluoride, malate, tartrate, or phosphonate anion to the composition;
• or
• a tetraalkoxy silane having from 1 to 3 carbon atoms in each alkoxy group, a partially hydrolyzed tetraalkoxy silane having from 1 to 3 carbon atoms in each alkoxy group;
• and mixtures of the foregoing retarders.

A binder-aggregate composition comprising a mixture of:

• A. magnesia aggregate;
• B. a hardenable phenolic resole resin solution having a pH of 4.5 to 9.5 and containing from 3% to 15% of water by weight of the resin, the quantity of said resin being from 3% to 15% based on the weight of the magnesia;
• and
• C. a retarder compound in an amount sufficient to retard the ambient temperature hardening of said resole and magnesia, said retarder being a compound selected from the group consisting of:
• a compound which provides an aspartate, bifluoride, citrate, fluoride, malate, tartrate, or phosphonate anion to the composition;
• or
• a tetraalkoxy silane having from 1 to 3 carbon atoms in each alkoxy group, a partially hydrolyzed tetraalkoxy silane having from 1 to 3 carbon atoms in each alkoxy group;
• and mixtures of the foregoing retarders.

A method for retarding the ambient temperature hardening of a mixture of a phenolic resole resin and magnesia aggregate which comprises mixing:

• A. magnesia aggregate;
• B. a hardenable phenolic resole resin solution having a pH of 5 to 8.5, a viscosity of 250 to 5,000 cps at 25.degree. C. and containing from about 3% to 15% of water based on the weight of resin, the quantity of said resin being sufficient to bind the magnesia on hardening of the resin;
• and
• C. a compound which provides anions selected from the group consisting of phosphate and oxalate to the mixture in an amount sufficient to retard the ambient temperature hardening of said mixture.

A method for retarding the ambient temperature hardening of a mixture of a phenolic resole resin and magnesia aggregate which comprises mixing:

• A. magnesia aggregate;
• B. a hardenable phenolic resole resin solution wherein the resin was prepared by use of a condensation catalyst selected from the group consisting of potassium hydroxide and an amine, said resole having a pH of 4.5 to 9.5, a viscosity of from about 100 to 10,000 cps at 25.degree. C., a water content of about 3% to 15% by weight, said resole being in a quantity sufficient to bind the magnesia on hardening of the resin;
• and
• C. a retarder compound in an amount sufficient to retard the ambient temperature hardening of said mixture, said retarder being compound selected from the group consisting of:
• a compound which provides an aspartate, bifluoride, citrate, fluoride, malate, tartrate, or phosphonate anion to the mixture;
• or
• a tetraalkoxy silane having from 1 to 3 carbon atoms in each alkoxy group, a partially hydrolyzed tetraalkoxy silane having from 1 to 3 carbon atoms in each alkoxy group;
• and mixtures of the foregoing retarders.