Abstract: A steam sensitive composition and a sterilization indicator composition which change in color only upon exposure to all of the conditions necessary for sterilization, that is, steam at a prescribed temperature for a prescribed period of time. The steam sensitive composition contains a metal complex and an exchange ligand. The metal complex is bis(dimethylglyoximato)nickel, bis(2-furyldioximato)nickel, zirconium chloranilate or bis(nioximato)nickel; and the exchange ligand is either 1) an aminocarboxylic acid which comprises from 1 to 6 carboxylic acid groups and from 1 to 4 amino groups, and its salts; or 2) citric or tartaric acids and their salts. The sterilization indicator contains as main components the steam sensitive composition described above, a binder, a solvent and preferably a color-change rate regulating component. The rate regulating components may be a cyanate or thiocyanate salt, and/or tartaric or citrate acid or their salts.

Abstract: Improved thermooptical sensing devices are provided wherein at various predetermined sectons of an optical fiber is juxtaposed a material characterized by a temperature dependent index of refraction. This material forms a temperature sensitive area which controls the transmission of light through the optical fiber thereby allowing detection of temperature changes along the fiber. The materials may be crystalline thermoplastic polymers, modified organic polymers containing inorganic modifiers, polymer systems containing discrete phases of organic polymers and inorganic additives or thermochromic inorganic compounds.

Abstract: A tissue simulating gel and a method for preparing the tissue simulating gel are disclosed. The tissue simulating gel is prepared by a process using water, gelatin, ethylene glycol, and a cross-linking agent. In order to closely approximate the characteristics of the type of tissue being simulated, other material has been added to change the electrical, sound conducting, and wave scattering properties of the tissue simulating gel. The result of the entire process is a formulation that will not melt at the elevated temperatures involved in hyperthermia medical research. Furthermore, the tissue simulating gel will not support mold or bacterial growth, is of a sufficient mechanical strength to maintain a desired shape without a supporting shell, and is non-hardening and non-drying.

Abstract: A fluorescent material is suggested whose decay time is used more particularly for determining a temperature. Said fluorescent material consists of pulverized crystals. The grain size of the pulverized and homogenized material is preferably <40 .mu.m.

Abstract: A device for indicating whether a rise in temperature above a predetermined value has occurred includes a support member, such as a label, on which a temperature-sensitive material is deposited. The material includes a large number of fracturable microcapsules containing a medium which changes from a solid state to a liquid state at the predetermined temperature value. The viscosity of the medium in its liquid state and the material of the support member are chosen such that the distance d.sub.1 by which the medium flows across the support member after the fracturing of the microcapsules so as to activate the device is indicative of the time between activation of the device and cooling of the device to below the predetermined temperature value. If the temperature is subsequently allowed to rise above the predetermined value, the medium will again assume its liquid state and will flow further across the support member, reaching a distance of, say, d.sub.

Abstract: Compositions of matter and methods of preparation are described for water and air stable, square planar transition metal double-complex salts which contain isonitrile ligands derivatized with long chain aliphatic groups. These salts are composed of two metal-containing complex ions: the cation is a tetrakis isonitrile metal ion and the anion is a tetrahalometallate or tetracyanometallate. These double-complex salts exhibit the novel property of thermochromism and are useful as temperature indicators and in imaging applications.

Abstract: Thermochromic compounds containing the [Pt(dipic)Cl].sup.- anion. These compounds are yellow and monomeric at high temperatures or in low concentrations and abruptly change to red and polymeric at low temperatures or higher solution concentrations. This unusual property allows them to be used as temperature sensors.

Abstract: A photoactivated time-temperature indicator is based on a leuco base system. A thermally insensitive, white ("inactive") leuco base (or a mixture of such leuco bases) is mixed, preferably in a polymeric matrix, with a material that generates acid upon exposure to light. Photoexcitation, preferably by UV or near UV light, causes the formation of a thermally sensitive, color-forming ("active") product. Following this activation step, a progressive color development occurs at a rate that increases with temperature. The indicator is useful for monitoring the freshness of perishable products, particularly those stored at subambient temperature.

Abstract: Whether a compound will thermoparticulate, that is, decompose to produce particles detectable by an ion chamber monitor or a condensation nuclei monitor and, if so, at what temperature, is predicted by determining the decomposition products of the compound, eliminating the compound if none of its decomposition products are greater than 25 .ANG., and using the temperature at which the decomposition products greater than 25 .ANG. have a vapor pressure of 10 millimeters as an estimate of the temperature at which the compound will decompose to produce products detectable by the monitor. Also disclosed are compounds which have been found to thermoparticulate at low temperatures.

Abstract: A new process is described which is useful for producing novel articles of manufacture useful for monitoring the time-temperature history of perishable items. The process initially involves forming a solution comprised of a diacetylenic monomer and a solvent. The solution is frozen, and the frozen solution having crystalline diacetylenic monomer therein is irradiated to partially polymerize the diacetylenic monomer. Partial polymerization of the crystalline diacetylenic monomer admixed with frozen solvent results in the production of a novel article of manufacture having color. The novel article of manufacture is comprised of frozen solvent, diacetylenic monomer, and colored polydiacetylene. Due to the intensity of the color of the polydiacetylene, the entire article of manufacture appears to be colored.The colored article of manufacture may be attached to various perishables to monitor the shelf life of the perishables.

Abstract: Thermochromic compounds containing the [Pt(dipic)Cl].sup.- anion. These compounds are yellow and monomeric at high temperatures or in low concentrations and abruptly change to red and polymeric at low temperatures or higher solution concentrations. This unusual property allows them to be used as temperature sensors.

Abstract: Compositions of matter and methods of preparation are described for water and air stable, square planar transition metal double-complex salts which contain isonitrile ligands derivatized with long chain aliphatic groups. These salts are composed of two metal-containing complex ions: the cation is a tetrakis isonitrile metal ion and the anion is a tetrahalometallate or tetracyanometallate. These double-complex salts exhibit the novel property of thermochromism and are useful as temperature indicators and in imaging applications.

Abstract: A series of chemically synthesized compounds known as metal mercury iodides or metal tetraiodomercurates having use as infrared detectors are made by reacting potassium tetraiodomercurate(II) with monovalent metal nitrates or iodides, such as thallium(I), indium(I) or copper(I) nitrates. In the case of gold, the gold(I) iodide is used because the nitrate is not known. The precipitated metal (thallium, indium, copper, gold, etc.) tetraiodomercurate is then filtered, dried, and purified (recrystallized) and pressed into a disk under high pressure. Alternatively, the material can be grown as a large crystal by zone melt fusion methods.

Abstract: An activatable time-temperature indicator consists of an oxygen-sensitive reaction product of a triarylmethane dye and a decolorant that is coated on a substrate and covered by an oxygen barrier. Optinally, an oxygen-permeable layer is between the coating and the oxygen barrier. The indicator is activated by removing the oxygen barrier. Following this activation step, a progressive color development occurs at a rate that increases with temperature. The indicator is useful for monitoring the freshness of perishable products, particularly those stored at sub-ambient temperature.

Abstract: A temperature indicating composition is provided for use on recoverable articles so that heating to produce recovery or to activate a heat-activatable sealant can be monitored. The composition comprises a thermochromic colorant in a binder and an activator that causes the thermochromic colorant to change color at a temperature lower than the temperature at which the colorant would change temperature in the absence of the activator. The thermochromic colorant can be folic acid and the activator can be an acid that has a pK of less than 4.2.

Abstract: A new process is described which is useful for producing novel articles of manufacture useful for monitoring the time-temperature history of perishable items. The process initially involves forming a solution comprised of a diacetylenic monomer and a solvent. The solution is frozen, and the frozen solution having crystalline diacetylenic monomer therein is irradiated to partially polymerize the diacetylenic monomer. Partial polymerization of the crystalline diacetylenic monomer admixed with frozen solvent results in the production of a novel article of manufacture having color. The novel article of manufacture is comprised of frozen solvent, diacetylenic monomer, and colored polydiacetylene. Due to the intensity of the color of the polydiacetylene, the entire article of manufacture appears to be colored.The colored article of manufacture may be attached to various perishables to monitor the shelf life of the perishables.

Abstract: A new reversible temperature indicating composition for use in temperature indicating instruments is diclosed which is capable of accurate temperature indication in a variety of colors and characterized by a minimum range of hysteresis so that the marking drawn in this composition can decolor at or close the temperature at which its coloring takes place. In addition, the composition can provide a wide variety of hues and can be readily prepared. These and other advantages are provided by the inclusion as a main ingredient of an ester compound having .DELTA.T value, defined .DELTA.T=melting point--clouding point, in the range under 3.degree. C., the value that determines a desirably small range of hysteresis.

Abstract: A thermochromic composition comprising (1) an electron-donating chromogenic material, (2) a 1,2,3-triazole compound, (3) a weakly basic, sparingly soluble azomethine or carboxylic acid primary amine salt, and (4) an alcohol, amide or ester serving as a solvent.

Abstract: Water-soluble polyacetylenic alkali metal salts from monomers and polymers of carboxymethyl urethanes of di-, tetra-, and hexayne diols, or from the corresponding diacids; useful in thermal and irradiation exposure indicators and/or in detection and/or removal of nonalkali metal ions dissolved in aqueous media.

Abstract: A thermochromic composition comprising:(i) at least one electron-donating organic chromogenic compound,(ii) at least one compound serving as a color developing material and selected from thiourea and derivatives thereof, guanidine and derivatives thereof, benzothiazole, and benzothiazolyl derivatives represented by the formula ##STR1## wherein A is --H, ##STR2## --NR.sub.2, --H.multidot.NR.sub.3 or --CSNR.sub.2 in which R is H, C.sub.1 -C.sub.10 alkyl, benzyl optionally substituted with C.sub.1 -C.sub.6 alkyl or cyclohexyl optionally substituted with C.sub.1 -C.sub.6 alkyl, with the proviso that all of R in --NR.sub.2, --H.multidot.NR.sub.3 and --CSNR.sub.2 can not be H, and M is Cu, Zn, Fe, Ni, Co or Te, and(iii) and at least one compound serving as a desensitizer and selected from the group consisting of alcohols, esters, ketones, ethers, acid amides, carboxylic acids and hydrocarbons.

Abstract: An elapsed time indicator in which an indicator, such as a flowable colorant, is releasably contained within an enclosure at least a portion of which is a volatilizable, preferably sublimable, substance.

Abstract: Thermographic cholesteric coating compositions, containing cholesteric microcapsules, and coated plates are provided which give gray-red-green-blue coated temperature-responsive visual displays, over about a 3.degree. or 4.degree. C. range. Formulations are devised to give the displayed range, in about 1.degree. C. intervals from about 28.degree. C. to about 37.degree. C. The microcapsules contain about 55% oleyl cholesteryl carbonate, about 2.0 to about 5.0% cholesteryl propionate and about 4.5 to about 7.2% of cholesteryl chloride. Coatings containing two different microencapsulated formulations, both selected within the above formulation range give thermographic plates showing a temperature-responsive visual display of seven distinct color shades, over about a 4.degree.-7.degree. C. range, without loss of sensitivity and without loss of noticeable color intensity.

Abstract: System and means for irreversibly recording the incidence of a predetermined temperature comprising a cholesteric liquid crystal system and an activator material capable of interacting with the liquid crystal system to induce a unique irreversible change in the optical properties thereof sustantially at the predetermined temperature. The system preferably includes means for separating the liquid crystal system and activator at temperatures below the activation temperature of the activator.

Abstract: A liquid melt becomes converted to crystalline form at a particular temperature either spontaneously or when artificially nucleated. The liquid releases heat at crystallization. If the liquid is in a supercooled state when it begins to crystallize, its temperature will rise from the particular temperature at which it is nucleated.Another liquid material is mixed with the liquid to be crystallized. The liquid additive has properties of forming a metastable solid together with the crystallizing material. When the liquid additive exsolves, the crystalline aggregate is weakened and is easily decomposed into fragments of small size. The liquid additive materials may include monohydric alcohols, diols and triols. The liquid additive material may be included in the liquid to be crystallized, in small amounts, amounts to two percent (2%) to five percent (5%) being typical.

Abstract: Thermographic plates particularly for medical investigation are provided comprising a polymer film substrate coated with single-droplet microcapsules having core material consisting essentially of about 55 to about 75% of cholesteryl pelargonate, about 14 to about 35% isostearyl cholesteryl carbonate, about 2.0 to about 6.0% of cholesteryl propionate and about 4.5 to about 7.2% of cholesteryl chloride. The coated plates give a gray-red-green-blue temperature-responsive visual display over a 3.degree. or 4.degree. C. range. Thermographic plates wherein the coatings contain two different microencapsulated formulations, both selected from the above formulation range, show a temperature responsive visual display of seven distinct color shades over about a 4.degree.-7.degree. C. range.

Abstract: A temperature measuring device engageable with a surface of any contour to determine the individual temperature of each of the several portions of the surface by providing a thermal map. The map is observable and may be photographed if a record thereof is desired.The temperature measuring device has a portion engageable with the surface and conformable to the surface. The portion which engages the surface includes a coating of cholesteric material, such as microencapsulated liquid crystal material which is temperature-sensitive and light-reflecting. The device also includes a transparent fill material therewithin to transmit the thermal image or map therethrough. Thus, a thermal map or image of the surface is provided. The thermal map is observable and/or recordable through another portion of the device.

Abstract: Device which visually indicates exposure to a temperature within a predetermined range for a predetermined length of time. An opaque microporous sheet has a colored stratum on the back and a transparent fusible coating on the face. The coating is a solid solution of amorphous rubbery polymer in crystallizable solvent which, upon melting, gradually penetrates and transparentizes the microporous layer, rendering the colored stratum visible.

Abstract: A pigment for a color-changing heat indicator comprising a product obtained by interaction of an aqueous solution containing ions of copper and mercury with an aqueous solution of a nitrogen-containing organic compound: an amide of carbonic acid, an amide of thiocarbonic acid, a tertiary amine to give a reaction mixture which is reacted with an aqueous solution containing ions of iodine at an atomic ratio of copper:mercury:iodine equal to 2:1.5:3-5 and an amount of the nitrogen-containing organic compound equal to 0.8-8% of the total content of copper and mercury; the pigment has its critical temperature of from 38.degree. to 70.degree. C. and a heat-resistance of from 160.degree. to 180.degree. C.

Abstract: In providing an adhesive connection or a seal using a thermoplastic adhesive for securing materials together, a thermochrome dye is added to the thermoplastic adhesive so that it provides a color change in the temperature range between the temperature where a satisfactory moistening effect is achieved and the temperature where the satisfactory moistening effect is no longer present.

Abstract: A patch of temperature-sensitive liquid crystal material adheres to a patient's skin to serve as an indicator of infiltration during intravenous (or intraarterial, intra-lymphatic vessel, etc.) insertion procedures. The material is selected so as to have a constant color over a temperature range which spans the normal skin temperature range. The patch is placed immediately downstream of the insertion point and preferably has a straight forward edge to permit rapid color change over a broad section of the patch in response to infiltration. The patch may include a downstream extension, remote from the likely infiltration region, which experiences infiltration-responsive color change considerably later than the forward edge, thereby providing a color contrast to facilitate visual detection.

Abstract: An aging gauge comprising a container having a fixed or a variable sized t opening with a cap which can be opened to control the sublimation rate of a thermally sublimational material contained within the container. In use, the aging gauge is stored with an item to determine total heat the item is subjected to and also the maximum temperature to which the item has been exposed. The aging gauge container contains a thermally sublimational material such as naphthalene or similar material which has a low sublimation rate over the temperature range from about 70.degree. F. to about 160.degree. F. The aging products determined by analyses of a like item aged along with the aging gauge for which the sublimation amount is determined is employed to establish a calibration curve for future aging evaluation. The aging gauge is provided with a means for determining the maximum temperature exposure (i.e., a thermally indicating material which gives an irreversible color change, Thermocolor pigment).