Stock material or miscellaneous articles – Web or sheet containing structurally defined element or... – Including a second component containing structurally defined...
Reexamination Certificate
2001-04-23
2003-08-05
Hess, B. Hamilton (Department: 1774)
Stock material or miscellaneous articles
Web or sheet containing structurally defined element or...
Including a second component containing structurally defined...
C106S031290, C106S031330, C428S206000, C428S207000, C428S321300, C428S913000
Reexamination Certificate
active
06602594
ABSTRACT:
BACKGROUND OF THE INVENTION
The present invention relates to a heat-sensitive ink comprising a heat-sensitive composition, which can undergo an irreversible color tone change at a predetermined temperature to thus permit the recording of whether a specific substance is exposed to a temperature higher than a predetermined level or not, as well as a heat-sensitive indicator using the same.
There have been known products, for instance, processed food products, which should be heat-treated at a temperature higher than a specific level during the manufacture of the same. There have also been known some products or articles such as products for medical use and food products, which are deteriorated, decomposed and/or putrefied, if they are exposed to a temperature higher than a specific one. In addition, there have likewise been known such products as electric equipments and electric parts, which get out of order, are broken and/or possibly cause a fire due to overheat in case of, for instance, a motor.
As a means for detecting whether a particular product experiences or is exposed to a temperature exceeding a predetermined level or not, there have conventionally been used, for instance, temperature-indicating materials capable of changing their color tone upon exposure thereof to such a predetermined temperature.
As such temperature-indicating materials, there have been known those comprising heat-fusible substances and acid-base indicators, specific examples of which are disclosed in, for instance, Japanese Patent Provisional Publication No. Sho 61-12783 and Japanese Patent Provisional Publication No. Sho 61-14284. The temperature-indicating materials of this type are reversible temperature indicators since they undergo color change upon heating and the color tone thereof is returned back to the original one when they are cooled. If a temperature-indication material of this type is used, whether a product is exposed to a temperature exceeding a predetermined level or not can be confirmed by monitoring the color tone change of the material during heating. However, if the color tone change of such a material is not monitored, it is impossible to confirm if a product experiences a temperature exceeding a predetermined level once the time elapses and the temperature of the product is reduced. Moreover, it is also impossible to record and preserve such a temperature history of the product.
In addition, Japanese Patent Provisional Publication No. Hei 10-239172 discloses a device for monitoring the upper temperature limit, which comprises a thin film of pigmented solid paraffin and a thin solid paraffin film having the same quality and deposited on the former. This device is one prepared by forming a thin film of paraffin previously pigmented and then depositing a thin film of non-pigmented paraffin on the surface of the former and should have a predetermined shape. This device is designed in such a manner that, when the device is exposed to a temperature exceeding a predetermined one, the fused upper layer or non-pigmented paraffin thin film is admixed with the lower layer or the pigmented paraffin thin film likewise in the fused state to thus develop a color tone apparently different from that observed prior to the fusion.
Moreover, Japanese Utility Model Application Publication No. Sho 46-28235 discloses an irreversible label. This label should be produced as a three-dimensional structure and therefore, the application thereof is quite limited.
SUMMARY OF THE INVENTION
Accordingly, it is a first object of the present invention to provide a heat-sensitive composition, which undergoes an irreversible color change responding to a temperature change, which permits the use of a wide variety of dyestuffs, which can be used in printing irrespective of the shape of a target to be printed, which can be mass-produced and permits the reduction of the production cost thereof and which allows the systematization of temperatures for indication or detection.
The irreversible heat-sensitive composition according to the present invention developed to achieve the first object of the present invention comprises a mixture of a granular (or granular) or powdery heat-fusible substance having a melting point corresponding to a temperature to be recorded and a granular or powdery dyestuff diffusible into the fused heat-fusible substance through dispersion or dissolution.
It is a second object of the present invention to provide a heat-sensitive ink, which can indicate, with high precision, whether it is exposed to a temperature exceeding a predetermined level or it has a desired temperature history or not, through a clear color tone change.
The heat-sensitive ink according to the present invention developed to accomplish the second object of the present invention comprises the foregoing irreversible heat-sensitive composition and an ink vehicle capable of diffusing the fused heat-fusible substance therein.
According to another embodiment of the heat-sensitive ink of the present invention comprises microcapsules in which the foregoing irreversible heat-sensitive composition is enclosed or encapsulated.
It is a third object of the present invention to provide a heat-sensitive indicator, which can indicate, with high precision, whether it is exposed to a temperature exceeding a predetermined level or it has a desired temperature history or not, through a clear color tone change which the color change itself could be preserved, and could easily be mass-produced.
The heat-sensitive indicator according to the present invention developed to achieve the third object of the invention comprises a substrate, which the foregoing heat-sensitive ink is printed on.
DETAILED EXPLANATION OF THE INVENTION
The irreversible heat-sensitive composition according to the present invention comprises a mixture of a granular or powdery heat-fusible substance with a granular or powdery dyestuff.
The irreversible heat-sensitive composition preferably comprises 0.001 to 100 parts by weight of the granular or powdery dyestuff per 100 parts by weight of the granular or powdery heat-fusible substance.
The heat-fusible substance is a component, which determines the color change-temperature of the irreversible heat-sensitive composition and a substance, which has, under ordinary pressure, a melting point corresponding to the temperature to be recorded and which can be fused when heated to a temperature higher than the melting point and undergo a change in state from a granular or powdery state to a liquid state. The heat-fusible substance suitably used herein is at least one member selected from the group consisting of fatty acid derivatives, alcohol derivatives, ether derivatives, aldehyde derivatives, ketone derivatives, amine derivatives, amide derivatives, nitrile derivatives, hydrocarbon derivatives, thiol derivatives and sulfide derivatives.
Specific examples of fatty acid derivatives are myristic acid, palmitic acid, adipic acid, octanoic acid, tricosanoic acid, tetratriacontanoic acid, 2,3-dimethyl nonanoic acid, 23-methyl tetracosanoic acid, 2-hexenoic acid, brassidic acid, 2-methyl-2-dodecenoic acid, &bgr;-eleostearic acid, behenolic acid, cis-9,10-methylene octadecanoic acid, chaulmoogric acid, n-dodecyl 3,3′-thiodipropionate, trilaurin, palmitic acid anilide, stearic acid amide, zinc stearate, salicylic acid anilide, N-acetyl-L-glutamic acid, caproic acid-&bgr;-naphthylamide, enanthic acid phenylhydrazide, p-chlorophenacyl arachionate, cholesteryll formate, 1-aceto-2,3-distearin, pentadecyl thiolaurate, stearic acid chloride, palmitic acid anhydride, stearic acid-acetic acid anhydride, succinic acid, sebacic acid benzyl ammonium salt, 2-bromovaleric acid, methyl &agr;-sulfostearic acid sodium salt, and 2-fluoroarachic acid.
Specific examples of alcohol derivatives are octadecyl alcohol, cholesterin, D-mannitol, galactitol, hepta-triacontanol, hexadecan-2-ol, 1-trans-2-octadecenol, &bgr;-eleostearyl alcohol, cycloeicosanol, d(+)cellobiose, p,p′-biphenol, riboflavin, 4-chloro-2-methylphenol and 2-bromo-1-indanol.
Sp
Harumoto Daisuke
Miyata Sachie
Mizusawa Hiromichi
Hess B. Hamilton
Nichiyu Giken Kogyo Co., Ltd.
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