Temperature indicating compositions

Claim 1

A temperature indicating composition comprising a dispersion in an aqueous binder of a color changing electron donating compound having a melting point greater than about 300° F. and a polymeric electron phenolic accepting resin reactive with said electron donating compound to produce a visible and permanent color change and having a T g greater than 270° F. and non-volatility such that coatings containing the composition are stable upon exposure to dry heat at 284° F. for 30 minutes yet produce a fully developed visible and permanent color change when subjected to saturated steam at 250° F. for twenty minutes.

Claim 17

A method for recording exposure to saturated steam at 250° F. and 15 psi for a minimum of twenty minutes comprising the steps of: providing a temperature indicating material comprising a support coated on at least one surface with a composition comprising a dispersion in an aqueous binder of a color changing electron donating compound having a melting point greater than 300° F. and a polymeric electron accepting phenolic resin reactive with said electron donating compound to produce a visible and permanent color change and having a T g greater than 270° F. and non-volatility such that coatings containing said composition are stable upon exposure to dry heat at 284° F. for thirty minutes yet produce a fully developed visible and permanent color change when subjected to saturated steam at 250° F. for twenty minutes; exposing said material to an elevated temperature condition; and evaluating the color of said composition coated on said support to determine whether said composition was exposed to saturated steam at 15 psi or greater and temperatures of 250° F. and higher for twenty or more minutes.

Claim 18

A method for recording exposure to saturated steam at 250° F. and 15 psi for a minimum of twenty minutes comprising the steps of: providing a temperature indicating material comprising a support coated on at least one surface with a composition comprising a dispersion in an aqueous binder of a color changing electron donating compound having a melting point greater than 300° F. and a polymeric electron accepting phenolic resin reactive with said electron donating compound to produce a visible and permanent color change and having a T g greater than 270° F. and non-volatility such that coatings containing said composition are stable upon exposure to dry heat at 284° F. for thirty minutes yet produce a fully developed visible and permanent color change when subjected to saturated steam at 250° F. for twenty minutes; exposing said material to an elevated temperature condition; and evaluating the color of said composition coated on said support to determine whether said composition was exposed to saturated steam at 15 psi or greater and temperatures of 250° F. and higher for twenty or more minutes.

Claim 19

A method for recording exposure to saturated solvent vapors at 275° F. and 20 psi for a minimum of twenty minutes, comprising the steps of: providing a temperature indicating material comprising a support coated on at least one surface with a composition comprising a dispersion in an aqueous binder of a color-changing electron donating compound having a melting point greater than 300° F. and a polymeric electron accepting phenolic resin reactive with said electron donating compound to produce a visible and permanent color change and having a T g greater than 270° F. and non-volatility such that coatings containing said composition are stable upon exposure to dry heat at 284° F. for thirty minutes yet produce a fully developed visible and permanent color change when subjected to saturated solvent vapors at 275° F. for twenty minutes; exposing said material to an elevated temperature condition; and evaluating the color of said composition coated on said support to determine whether said composition was exposed to saturated solvent vapors at 20 psi or greater and temperatures of 275° F. or higher for twenty or more minutes.

Claim 20

A method for recording exposure to saturated solvent vapors at 275° F. and 20 psi for a minimum of twenty minutes, comprising the steps of: providing a temperature indicating material comprising a support coated on at least one surface with a composition comprising a dispersion in an aqueous binder of a color-changing electron donating compound having a melting point greater than 300° F. and a polymeric electron accepting phenolic resin reactive with said electron donating compound to produce a visible and permanent color change and having a T g greater than 270° F. and non-volatility such that coatings containing said composition are stable upon exposure to dry heat at 284° F. for thirty minutes yet produce a fully developed visible and permanent color change when subjected to saturated solvent vapors at 275° F. for twenty minutes; exposing said material to an elevated temperature condition; and evaluating the color of said composition coated on said support to determine whether said composition was exposed to saturated solvent vapors at 20 psi or greater and temperatures of 275° F. or higher for twenty or more minutes.