초록 ▼

Disclosed are end point indicator compositions and devices containing them, particularly useful as air freshener devices, comprise compositions containing a polar indicator dye which assumes a first color or is colorless in the presence of a room temperature volatilizable solvent which is initially

Disclosed are end point indicator compositions and devices containing them, particularly useful as air freshener devices, comprise compositions containing a polar indicator dye which assumes a first color or is colorless in the presence of a room temperature volatilizable solvent which is initially present in excess and a small amount of a proton donating compound. The indicator dye assumes a second color visually distinct from the first color in the presence of the proton donating compound after the majority of the solvent escapes from the remainder of the composition. Optionally, the compositions further include color change developers and/or secondary dyes to render the change to the second color, indicating attainment of the end point, more apparent to a user.

대표청구항 ▼

A time-color indicator composition to visually indicate when a product associated with said composition has become ineffective for its intended use, said composition comprising: (a) a room temperature volatilizable, nonaqueous liquid solvent; (b) an effective amount of an indicator dye which is subs

A time-color indicator composition to visually indicate when a product associated with said composition has become ineffective for its intended use, said composition comprising: (a) a room temperature volatilizable, nonaqueous liquid solvent; (b) an effective amount of an indicator dye which is substantially nonvolatile at room temperature and is soluble in said solvent, said dye assuming a first color when dissolved in said solvent; and (c) an effective amount of at least one proton donating compound wherein said dye assumes a second color visually distinct from said first color when the dye is in contact with only said compound, wherein the ratio of the solvent to the dye and the proton donating compound is such that upon evaporation of said solvent, said dye visually changes from said first color to said second color, assumption of said second color indicating that the product has become ineffective and wherein all components of said composition are selected to result in a composition which is essentially neutral in pH.