Allied Chemical Corporation

Allied Corporation

Kwok C Yee

Ray H Baughman

Ronald Richard Chance

Gordhanbhai N Patel

Anthony F Preziosi

Granville G Miller

Certain polyacetylenes exhibit reversible color changes at transition temperatures in the range -180.degree. to 220.degree. C., wherein the thermochromic cycles can be repeated many times with no apparent degradation and little change in spectroscopic properties. These thermochromic polyacetylenes are useful in temperature-indicator and indicia-display device applications. A process for laser-beam recording of images is described employing a thermochromic polyacetylene, in which the hysteresis properties of the polyacetylene can be suitably altered allowing for selectively storing or erasing the formed image.

Tempeature measurement and display of indicia using thermochromic

New fluorinated benzenesulfonate diacetylene compositions are described which are useful in time-temperature devices for monitoring the shelf-lives of perishable articles. The compositions are solid-state polymerizable by thermal annealing or exposure to actinic or high energy ionizing radiation. Some of the compositions, in addition, exhibit relatively longer polymerization induction periods, compared to other known diacetylene compositions, and an 'autocatalytic' effect upon polymerization during which a rapid color change occurs. These characteristics are extremely useful in monitoring situations which require a striking color change as an indication that a particular time-temperature history profile, e.g. shelf-life, has expired.

Fluorinated benzenesulfonate diacetylenes

Thermochromic polyacetylenes used in laser beam recording method

An improved recording device is described, useful for measuring the integrated time-temperature or integrated radiation-dosage history of an article, comprising a substrate onto which an acetylenic compound, containing at least two conjugated C.tbd.C groups, in an inactive form, is deposited. The inactive form is capable of being converted by melt or solvent recrystallization to an active form, which undergoes 1,4-addition polymerization resulting in an irreversible, progressive color change. The color change produced at any given point in time represents an integrated time-temperature history of thermal annealing or integrated radiation-dosage history of exposure to actinic radiation to which an article has been exposed. Also described is a process for producing an inactive form of the acetylenic compound. A film and a fiber, made from the inactive form of an acetylenic compound are also described.

Diacetylene time-temperature indicators

Liquid phase processable crystalline diacetylene polymers are obtained by the solid state reaction of monomers having the formula

Crystalline diacetylene polymers

Thermochromic polyacetylenes containing urethane groups

Novel carbazolyl diacetylenic monomers and polymers are provided. The monomers have the structure ##STR1## where 'm' and 'n' are integers of from 0 to 10, X and Y are independently selected from the group consisting of --H, --Cl, --Br and --NO and R is a member selected from the group consisting of --CH.sub.3, --OH, --OCONHR' and ##STR2## where R' is an alkyl, aryl or ester derivative and X' and Y' are independently selected from the group consisting of --H, --Cl, --Br and --NO. The monomers are conveniently prepared by oxidative coupling of terminated carbazolyl acetylenes, by cross coupling of bromoacetylenes with terminal acetylenes, or by substitution reaction of alkali carbazolides with the appropriate diacetylenes. The polymers are prepared by 1,4-addition reaction of the corresponding monomers in the solid state. The polymers are particularly useful as photoconductors and as non-linear optical materials. The monomers are useful as high energy radiation dosage indicators.

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Randolph, NJ, United States of America

Kwok C Yee