JP5151746B2 - Manufacturing process check label showing temperature and time history - Google Patents

Description

  The present invention relates to a manufacturing process check label for displaying a history of temperature and time in a manufacturing process of a predetermined article. More specifically, a manufacturing process check label comprising a polymer composition comprising a polymer and a dye, wherein the polymer composition is a polymer in which a dye is fixed in a specific molecular dispersion state at a specific temperature or higher. The manufacturing process check label is characterized in that it is irreversibly discolored to a hue different from the initial hue when held at a temperature of a certain time or more, and the manufacturing process check label is applied to a predetermined article. The present invention relates to a method of displaying a temperature and time history experienced by the predetermined article.

For example, products that are sensitive or weak to heat require care when stored. In particular, products that are sensitive to heat, such as chemicals, become unusable when the storage upper limit temperature is exceeded. When storing such a product, it is possible to check the storage state by using a temperature indicating label or the like of a quality display medium. For example, release of crystal water upon heating of inorganic compounds such as CoCl ₂ · (CH ₂ ) ₆ N ₄ · 10H ₂ O, structural change upon heating of organic compounds such as spiropyran, leuco dyes, solid acids and alcoholic properties There are some which display the presence or absence of temperature change by color development or decoloration by a chemical change at the time of heating of a system composed of three components of a compound having a hydroxyl group.

  For example, a polyolefin non-woven fabric impregnated with an agar-based aqueous gel, and a non-woven polyolefin non-woven fabric, if necessary, are bonded between the polyolefin film and a polyolefin film printed with a white oil-based ink containing a water-soluble dye. Before the freezing operation, the water-soluble dye is contained in the white oil-based ink and does not develop color, but once frozen, when the temperature of the contents rises to the thawing temperature, The water-leaching dye dissolves and the white oil-based ink printing surface is colored by the water leached through the fine holes, so that the temperature change of the contents can be easily indicated. (See Patent Document 1) is known.

  In addition, a liquid crystal / polymer composite film in which liquid crystal particles are dispersed in a polymer matrix is composed of two conductive substrates or a sheet sandwiched between a conductive substrate and a protective layer. A color display medium that can be used repeatedly to record the heat history of the stored temperature environment of the quality display medium by coloring or decoloring, and can determine the heat history of the stored temperature environment (Patent Document) 2) is known.

  In addition, there is a two-phase holding region in the normal temperature range where both the colored state and the colorless state can coexist, exhibiting hysteresis characteristics due to temperature changes and exhibiting the tautomerism between the colored state and the colorless state or between the colored state and the colored state. By providing a layer in which the thermochromic color-changing color-changing thermochromic material is fixed in a dispersed state in the reversible thermochromic layer, the color of the surface can be obtained by simple means such as changes in the outside air temperature, hand contact or friction. Stationery (see Patent Document 3) that can change patterns and conceal various images and contributes to diversification and differentiation of the design as well as temperature-related effects is known.

  Furthermore, the thermosensitive recording layer, a permeation layer mainly composed of a pigment and a binder, a microcapsule-containing layer containing a thermosensitive material having a melting point of 0 ° C. or higher, and a protective label are sequentially laminated on the support. By recording automatic recognition information such as a barcode on the thermosensitive recording layer in a room temperature environment or in a freezer / refrigerated room, and applying pressure to the microcapsule and attaching it to a frozen / refrigerated product immediately before being applied in the freezer / refrigerator room A temperature indicating label (see Patent Document 4) is known in which an image recorded in advance is irreversibly changed when the frozen and refrigerated product is exposed to a predetermined temperature of 0 ° C. or higher.

These conventional display bodies that display the presence or absence of temperature changes are extremely complicated in configuration, and even if they can display the experienced temperature, they can display the history of the elapsed time at that temperature. Nothing existed. Therefore, it has been desired to provide a display body that has a simple configuration and can display both the temperature and the time history at that temperature.
JP 07-049656 A Japanese Patent Laid-Open No. 11-237599 JP 09-295589 A JP 2004-184920 A

  The objective of this invention is providing the display body which is excellent in the simplicity of a structure, and can display both the temperature of the articles | goods which should be displayed, and the elapsed time in the temperature.

  As a result of intensive studies to solve the above problems, the present inventors have found that the above problems can be solved by the following means, and have reached the present invention. That is, this invention consists of the following structures.

  (1) A production process check label comprising a polymer composition comprising a polymer and a dye, wherein the polymer composition is a polymer in which a dye is fixed in a specific molecular dispersion state and has a specific temperature or higher. A manufacturing process check label, which is irreversibly discolored to a hue different from an initial hue when held at a temperature for a predetermined time or more. In the present invention, the “fixation” is not limited to dispersing the dye in the polymer, but also includes copolymerizing the dye with the polymer.

  (2) The production process check label according to the above (1), wherein the dye exhibits a different hue depending on a molecular dispersion state of the dye.

  (3) The production process check label according to (1), wherein the dye is an associative fluorescent dye having different fluorescence wavelengths in an excimer state and a monomer state.

  (4) The production process check label according to (1), wherein the dye molecules are fixed in the polymer in a monomer state.

  (5) The production process check label according to (1), wherein the dye is an oligophenylene vinylene compound represented by the following formula.

(In the formula, each R independently represents hydrogen, an alkyl group having 1 to 36 carbon atoms, an alkoxy group having 1 to 36 carbon atoms, a hydroxyl group, a hydroxyalkyl group, a halogen group, a phenylene vinylene group or a cyano group.
Each R ₁ independently represents hydrogen, an alkyl group having 1 to 36 carbon atoms, an alkoxy group having 1 to 36 carbon atoms, a hydroxyl group, a hydroxyalkyl group, a halogen group, a phenylene vinylene group or a cyano group;
R ₂ each independently represents hydrogen, an alkyl group having 1 to 36 carbon atoms, an alkoxy group having 1 to 36 carbon atoms, a hydroxyl group, a hydroxyalkyl group, a halogen group, a phenylene vinylene group or a cyano group. )
(6) The manufacturing process check according to (5), wherein R is hydrogen or a hydroxyl group, R ₁ is an alkoxy group having 1 to 36 carbon atoms, and R ₂ is an alkoxy group having 1 to 36 carbon atoms. label.

(7) The production process check label according to (5), wherein R ₁ or R ₂ is an alkoxy group having 15 to 36 carbon atoms.

  (8) The production process check label according to (1), wherein the content of the dye in the polymer composition is 0.01 to 10% by weight.

  (9) The production process check label according to (1), wherein the polymer is polyester.

  (10) A method of displaying the temperature and time history of a predetermined article using the external stimulus display body described in (1) above.

  The manufacturing process check label of the present invention can display the history of the elapsed time of the predetermined article above a specific temperature by sticking it on the predetermined article.

  For example, by attaching the manufacturing process check label of the present invention to a package such as food, whether the food has been subjected to heat sterilization or heat treatment at a specific temperature or higher in the manufacturing process, or at an appropriate temperature. Whether it is stored or not can be determined by looking at the hue of the manufacturing process check label. Therefore, it is possible to confirm that the food has been sterilized at a specific temperature or higher for a predetermined time or that the frozen food has not been exposed to a high temperature for a predetermined time or longer. It is effective for guaranteeing and confirming. Accurate temperature and time course measurements and recordings in a small number of subjects are possible with the development of today's electronics and sensors, but for example knowing the individual temperature time history of countless articles in the food manufacturing process Although it is extremely difficult in terms of cost, according to the present invention, it is possible to easily know the individual temperature time history of these countless articles by attaching a manufacturing process check label to each article. Become.

  In the present invention, a polymer composition is prepared by selecting the type of dye and polymer to be used, the blending ratio, etc., and is suitable for sensing a desired temperature and a desired elapsed time at that temperature. A process check label can be easily obtained.

  Furthermore, the production process check label of the present invention only needs to contain a polymer composition composed of a polymer and a dye fixed in a specific molecular dispersion state in the polymer, which is simpler than conventional display bodies. It is a structure and can be easily manufactured using a polymer composition.

  The polymer composition in the present invention is a composition in which a dye is fixed in a specific molecular dispersion state in a polymer, and is different from an initial hue when held at a temperature above a specific temperature for a certain period of time. It has the property of changing color to hue. By utilizing the properties of such a polymer composition, it is possible to obtain a manufacturing process check label that is attached to a predetermined article and used to display the temperature and time history of the predetermined article. Moreover, it is preferable that the change of the hue of a polymer composition is stepwise, and by making it stepwise, the temperature and time history can be displayed in more detail.

  The polymer used in the present invention is not particularly limited as long as it can uniformly dissolve and disperse the following dyes, but those in which the physical properties of the polymer compound change reversibly upon heating and cooling are preferable, and the processability is high. From the viewpoint, a solvent-soluble polymer or a thermoplastic polymer is preferable. Specifically, polyolefins (polyethylenes, polypropylene, etc.), cycloolefins and copolymers thereof, polyesters (polyethylene terephthalate (PET), PET and 1,4-cyclohexanedimethanol copolymer (PETG)) , Polybutylene terephthalate, polyethylene naphthalate, etc.), polycarbonates, polyimides, polyamideimides, polyetherimides, polyurethanes, polyvinyls (polyvinyl chloride, polyvinylidene chloride, polyvinyl fluoride, polytetrafluoroethylene, poly Chlorotrifluoroethylene, polyvinyl acetate, polyvinyl alcohol, poly 2-vinyl pyridine, polyvinyl butyral, etc.), polystyrenes, polyamides (nylon 6, nylon 6.6, Niro) 12, nylon 4.6, etc.), polyacrylonitrile, polyacrylic acids, polyacrylates (polymethyl methacrylate, polymethacrylate, polybutyl acrylate, etc.), polyacetals, polyacrylamides, polyglycolic acid, copolymer (acrylonitrile) Butadiene styrene, ethylene vinyl acetate, etc.), polyallyl sulfones, polyphenylene oxides, thermosetting resins, regenerated celluloses (cellophane, cellulose acetate, cellulose acetate butyrate, etc.), natural fibers (wool, silk, cotton, etc.), Elastomers include styrene butadiene copolymer, polybutadiene, ethylene propylene copolymer, polychloroprene, polyisoprene, nitrile rubber, silicone rubber, and thermoplastic elastomers. Preferred examples include homopolymers of synthetic polymers such as these and copolymers thereof. In addition, biodegradable polymers such as gelatin, cellulose, polylactic acid, polycaprolactone, modified polyvinyl alcohol, and casein, and hydrocarbon compounds such as paraffin are also included. Among these, it is preferable to use polyesters, and it is particularly preferable to use PET and PETG.

  The dye used in the present invention exhibits a different hue depending on the molecular dispersion state of the dye. In addition, the dye of the present invention is such that it is uniformly dissolved and dispersed in the polymer in a specific molecular dispersion state, and the specific molecular dispersion state is maintained even when the dispersion composition is molded. When the manufacturing process check label using such a dye is held at a specific temperature or higher for a predetermined time or longer, the molecular dispersion state of the dye molecules changes in the polymer composition contained in the display body, and as a result The hue of the dye on the process check label changes.

  The specific dye is preferably a fluorescent dye, more preferably an associative fluorescent dye having different fluorescence wavelengths in the excimer state and the monomer state, and the difference between the excimer light emission and the monomer light emission is greater than 100 nm. Large fluorescent dyes are preferred. More preferably, it is 120 nm or more, and most preferably 150 nm or more.

  Usually, when fluorescent dye molecules are close to each other, when one of them absorbs light and enters an excited state, it forms an excimer (excited aggregate) with the other ground state molecule, and excimer emission on the longer wavelength side than monomer emission Indicates.

  In this specification, the excimer state is a state in which a plurality of molecules are associated with each other or are close to each other, and a wavelength longer than that of light emitted by a dye molecule alone due to energy transfer between the molecules due to the close proximity of the molecules. It means a state that causes light emission at. On the other hand, the monomer state is a state in which the single molecules are further away from each other than the excimer state, so energy transfer between the molecules does not occur, and the light emission of the dye molecule at that time occurs when a single excited molecule returns to the ground state. It means a state corresponding to light emission. However, since the boundary between the transition between the monomer state and the excimer state is continuous, the dye molecules in the polymer composition partially pass through the mixed state of the monomer state and the excimer state. The luminescence appears to change continuously. In order to display the history and progress, it is preferable that the hue of the polymer composition changes color stepwise according to the temperature history and the amount of deformation.

  Moreover, since the dye used in the present invention can visually confirm the temperature and time history, it is preferable that the absorption spectrum in the visible light region also shows different spectra in the excimer state and the monomer state.

  The fluorescent dye is preferably an oligophenylene vinylene compound, and examples of the oligophenylene vinylene compound include compounds represented by the following formula.

(In the formula, each R independently represents hydrogen, an alkyl group having 1 to 36 carbon atoms, an alkoxy group having 1 to 36 carbon atoms, a hydroxyl group, a hydroxyalkyl group, a halogen group, a phenylene vinylene group or a cyano group.
Each R ₁ independently represents hydrogen, an alkyl group having 1 to 36 carbon atoms, an alkoxy group having 1 to 36 carbon atoms, a hydroxyl group, a hydroxyalkyl group, a halogen group, a phenylene vinylene group or a cyano group;
Each R ₂ independently represents hydrogen, an alkyl group having 1 to 36 carbon atoms, an alkoxy group having 1 to 36 carbon atoms, a hydroxyl group, a hydroxyalkyl group, a halogen group, a phenylene vinylene group or a cyano group.

In the above formula, R is preferably hydrogen is a hydroxyl group, more preferably hydrogen. R ₁ is preferably an alkoxy group having 1 to 36 carbon atoms, and more preferably an alkoxy group having 15 to 36 carbon atoms. R ₂ is preferably an alkoxy group having 1 to 36 carbon atoms, and more preferably an alkoxy group having 1 to 3 carbon atoms.

  In the polymer composition used in the present invention, it is preferable that the polymer to be used and the dye have appropriate compatibility (affinity). Here, moderate compatibility means that when a polymer and a dye fixed in a specific molecular dispersion state in the polymer are held at a temperature higher than a specific temperature for a certain period of time, or by a certain amount by an external force. When it is deformed as described above, the compatibility is such that it changes irreversibly to a hue different from the initial hue. For example, in the case of using an associative fluorescent dye having a fluorescence wavelength in which excimer emission and monomer emission are different, if the compatibility between the dye and the polymer is too low, they are separated without being dissolved even if they are heated and mixed. The associative dye molecules in the excimer state cannot be separated and do not shift to the monomer state. On the other hand, if the compatibility between the dye and the polymer is too high, the dye is completely dissolved in the polymer, so that the dye molecules are dispersed in a separated state and shift to excimer emission after heat treatment. Without any change in hue.

For example, when the polymer is a polyester resin (especially polyethylene terephthalate, PETG) or a polyolefin (especially polyethylene), the combination of the polymer and the dye having appropriate compatibility is carbon as R ₁ or R _2. By using the oligophenylene vinylene compound represented by the above formula having an alkoxy group of several 15 to 36 as a dye, the compatibility between the polymer and the dye becomes appropriate, and the dye in the polymer is at a temperature higher than a specific temperature. When held for a certain period of time or when deformed by a certain amount or more by an external force, the color changes to a hue different from the initial hue.

  In the present invention, the content of the dye in the polymer composition is preferably 0.01 to 10% by weight, more preferably 0.5 to 5% by weight. When the content of the dye is within such a range, when the dye in the polymer composition is held for a certain period of time at a temperature equal to or higher than a specific temperature, or when it is deformed by a certain amount or more by an external force, the initial hue and Is preferably adjusted according to the compatibility between the polymer and the dye so that the color changes to a different hue.

  The polymer composition comprising the polymer and the dye of the present invention may be composed only of the polymer and the dye, but in addition, organic, inorganic and organometallic toners, and fluorescent whitening An agent etc. can be included, and the color change of the polymer composition can be further clarified by containing one or more of these. Moreover, other arbitrary polymers, antistatic agents, antifoaming agents, dyeability improving agents, dyes, pigments, matting agents, stabilizers, antioxidants, and other additives may be contained. As antioxidants, aromatic amines, phenols and other antioxidants can be used, and as stabilizers, phosphoric acid and phosphoric acid ester-based phosphorous, sulfur-based, amine-based stabilizers, etc. Can be used.

  Although the form of the polymer composition in this invention is not specifically limited, It is preferable that it is a form of a film, a fiber, or a fine substance. Here, the fine material means a fine molded product such as a particle or a fine piece, and the shape is not particularly limited. Although the thickness in the case of the form of a film is not specifically limited, 10-200 micrometers is preferable.

  The production process check label of the present invention preferably uses a polymer composition in which dye molecules are dispersed in a polymer in a monomer state. In this case, when the polymer composition is exposed to a specific temperature or more for a predetermined time or more, the dispersion state of the dye molecules shifts to the excimer state, and the hue of the dye changes. Here, the specific temperature is preferably a temperature equal to or higher than the glass transition temperature of the polymer composition. Usually, the dispersion state of the polymer composition does not change below the glass transition temperature, but the dispersion state may change when exposed to such temperature for a very long time even below the glass transition temperature.

  As a method of obtaining a polymer composition in which a dye is dispersed in a polymer in a monomer state, for example, a pigment is mixed in a dissolved polymer and dispersed, and then cooled more rapidly than usual using water or the like during molding. A method of obtaining a desired polymer composition by solidifying while dispersed is mentioned. When an associative fluorescent dye having different fluorescence wavelengths in the excimer state and the monomer state is used as the dye, since the dyes gather together, it is a polymer material that has loose bonds at high temperatures. Then gradually meet and the hue turns red. The temperature at which the dye and the polymer are dissolved is not particularly limited as long as it is a temperature at which both can be uniformly dissolved and dispersed, but is usually a temperature not lower than the glass transition temperature, preferably from the glass transition point (K). It is between the glass transition point (K) × 2.0, and more preferably between the glass transition point (K) × 1.1 and the glass transition point (K) × 1.7.

  In addition, the polymer composition used in the present invention is not limited to the one in which the dye is dispersed in the polymer in the polymer state by melt blending as described above, but the one in which the dye is dispersed in the monomer state by another manufacturing method. For example, it may be a solution blend in which a dye and a polymer are dissolved in a solvent, or a polymer composition obtained by copolymerizing a dye with a polymer. A production process check label using a polymer composition obtained by copolymerization can delay the hue change rate, and can suppress bleeding out of the dye during use. However, it is considered that such a polymer composition requires a larger amount of dye than the polymer composition obtained by melt blending in order to cause a hue change, and the amount of the dye added is increased within a range of about 10% by weight or less. It is desirable.

When the dye is copolymerized with a polymer, a reactive substituent is required at the end of the dye. Here, the end of the dye means, for example, the end of a substituent such as R, R ₁ , R ₂ in the above formula. The reactive substituent is not particularly limited as long as it is a substituent that can be copolymerized with a polymer. For example, a hydroxyl group, an amino group, a carboxyl group, an acrylic acid group, an acrylate group, an isocyanate group, an epoxy group, Examples include cyanate esters and benzoxazines, and a hydroxyl group is particularly preferable.

  There are no particular restrictions on the polymer used to copolymerize the dye, and not only the dye is copolymerized with the main chain of the polymer, but also the dye is copolymerized with the polymer side chain to control the association of the dye. You may let them. Further, by using a branched polymer, hyperbranch, dendrimer, cross-linked polymer, etc. as the matrix polymer, the mobility of the more copolymerized dye is increased, and the color change threshold is clarified.

  In the method of displaying the temperature and time history of a predetermined article using the manufacturing process check label of the present invention, a manufacturing process check label using a polymer composition in which dye molecules are fixed in a monomer state in a polymer is provided. It is preferable to use it. As a specific method, it is possible to determine whether or not the food has passed a predetermined elapsed time at a specific temperature or higher by attaching the production process check label of the present invention as a package of food or the like. There is a method of discriminating by checking the hue of the check label.

Next, the present invention will be described more specifically with reference to examples and comparative examples.
In the following examples, the solution viscosity (reduced viscosity ηsp / c (dl / g)) of the polyester resin was measured by mixing 0.10 g of the polyester resin with 25 cc of a mixed solvent of phenol / tetrachloroethane (mass ratio 6/4). And measured at 30 ° C. using an Ubbelohde viscosity tube. Further, the glass transition point was measured with a differential scanning calorimeter (DSC) (model number: DSC2920) manufactured by TI Instrument Co., Ltd. under a nitrogen gas atmosphere at a heating rate of 10 ° C./min.

Example 1
(Production of polymer composition)
In a reaction vessel equipped with a thermometer, a stirrer, a reflux condenser tube and a distillation tube, the composition ratio of the copolymer polyester resin obtained is 47 mol parts terephthalic acid, 42 mol parts isophthalic acid, 11 mol parts sebacic acid, ethylene The diol / dicarboxylic acid molar ratio was charged at 1.5 so that the glycol was 56 mol parts and the neopentyl glycol 44 mol parts, and 0.3 mol parts of triethylamine was added as an additive in a nitrogen atmosphere at 2 atm. The temperature was gradually raised to 230 ° C. over 4 hours, and the esterification reaction was performed while removing distilled water out of the system. Subsequently, after returning to normal pressure, 0.11 part of titanium tetrabutoxide was added and stirred for 5 minutes. Then, initial polymerization under reduced pressure was performed to 10 mmHg over 30 minutes and the temperature was raised to 250 ° C., and further 1 mmHg or less. Was subjected to late polymerization for 60 minutes to obtain a copolyester resin. The copolyester resin had a glass transition temperature of 45 ° C. and a solution viscosity of 0.54. Thereafter, the obtained copolyester resin was remelted to obtain a C18RG dye in which R is hydrogen, R ₁ is an octadecyloxy group (C ₁₈ H ₃₇₀ ), and R ₂ is a methoxy group. 1% by weight was added to the polymerized polyester resin and melt blended for 10 minutes to obtain a polymer composition of the present invention in which the dye was monodispersed in the copolymerized polyester resin.

(Manufacturing colored bodies)
A four-necked 10 liter separable flask equipped with a thermometer, a condenser, and a stirring blade was charged with 100 parts by weight of the polymer composition obtained above, 200 parts by weight of methyl ethyl ketone, and 200 parts by weight of toluene, and the temperature was adjusted to 70 ° C. While maintaining, the solution was stirred and dissolved.

  The solution obtained in the above step was coated on a polyester film, the solvent was evaporated at 160 ° C., and then rapidly cooled by air drying to obtain a green coat film. Table 1 shows changes in hue over time when the film was stored at a temperature of 60 ° C.

Example 2 Production of Production Process Check Label Sheet As a dye in this example, C18RG in which R is hydrogen, R ₁ is an octadecyloxy group (C ₁₈ H ₃₇₀ ), and R ₂ is a methoxy group in the above formula Was used. Each dye was melt blended in PET by 0.9% by weight with a biaxial kneader, heated and pressed at 280 ° C., and then rapidly cooled with cold water to obtain a PET film containing a fluorescent dye having a thickness of 200 μm. The obtained film showed yellow-green monomer emission, the glass transition temperature was 75 ° C., and the solution viscosity was 0.7.

  An acrylic pressure-sensitive adhesive (SK1335 manufactured by Soken Chemical Co., Ltd.) was applied to one side of this film at a thickness of 5 μm to form a pressure-sensitive adhesive layer, and a manufacturing process check label sheet of the present invention was obtained. In addition, it does not specifically limit as an adhesive used. The form can be freely selected from emulsion, solvent, hot melt and the like. As the material, general materials such as acrylic, rubber (natural rubber, SBR, butyl rubber), silicone, fluororesin, and polyester are used. In particular, the use of a silicone-based adhesive is preferable in applications that require heat resistance and weather resistance. Table 2 shows the change in hue under ultraviolet light over time when the sheet was cut into 5 mm × 15 mm and held at a temperature of 90, 100, and 120 ° C. on a hot plate.

  In Table 2, the manufacturing process check label sheet obtained in Example 2 turns orange when the temperature-time product exceeds a certain value. This phenomenon is caused by the C18RG dye having a glass transition point (75 ° C.) of PET. ) Aggregates and exhibits excimer emission. It was also found that the film discoloration rate at a certain temperature increased in a single exponential manner with respect to the dye concentration and temperature. That is, the temperature-time product until the color change can be freely designed according to the dye concentration and the glass transition point of the matrix polymer.

  Further, the dyes used in Examples 1 and 2 showed a unique property that the absorption wavelength in the visible region also changed with excimer formation, and the color change could be clearly identified even under natural light. For this reason, since the manufacturing process check label of the present invention can detect a change in hue even under natural light, it has an excellent advantage that the temperature and time history can be confirmed without requiring irradiation with ultraviolet rays or the like. have.

  As described above, the present invention makes it possible to provide a general-purpose heat sensor using an inexpensive polyester material, and is expected to be used in a wide range of applications such as detection of heat history in the manufacturing process of foods and medicines.

  It should be understood that the embodiments and examples disclosed herein are illustrative and non-restrictive in every respect. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

  The production process check label of the present invention is a production suitable for sensing a desired temperature and the elapsed time at that temperature by preparing a polymer composition by selecting the kind of dye and polymer to be used, blending ratio, etc. Since a process check label can be obtained, it can be used effectively for the management of food and chemical safety according to various purposes.

Claims (9)

A manufacturing process check label comprising a polymer composition comprising a polymer and a dye,
The polymer composition is a polymer in which a dye is fixed in a specific molecular dispersion state,
The dye is an associative fluorescent dye having different fluorescence wavelengths in the excimer state and the monomer state,
The manufacturing process check label is irreversibly discolored to a hue different from an initial hue when held at a temperature equal to or higher than a specific temperature for a predetermined time or more.   The manufacturing process check label according to claim 1, wherein the dye exhibits a hue different depending on a molecular dispersion state of the dye.   The manufacturing process check label according to claim 1, wherein the dye molecules are fixed in the polymer in a monomer state. The manufacturing process check label according to claim 1, wherein the dye is an oligophenylene vinylene compound represented by the following formula.

(In the formula, each R independently represents hydrogen, an alkyl group having 1 to 36 carbon atoms, an alkoxy group having 1 to 36 carbon atoms, a hydroxyl group, a hydroxyalkyl group, a halogen group, a phenylene vinylene group or a cyano group.
Each R ₁ independently represents hydrogen, an alkyl group having 1 to 36 carbon atoms, an alkoxy group having 1 to 36 carbon atoms, a hydroxyl group, a hydroxyalkyl group, a halogen group, a phenylene vinylene group or a cyano group;
R ₂ each independently represents hydrogen, an alkyl group having 1 to 36 carbon atoms, an alkoxy group having 1 to 36 carbon atoms, a hydroxyl group, a hydroxyalkyl group, a halogen group, a phenylene vinylene group or a cyano group. ) The manufacturing process check label according to claim 4 , wherein R is hydrogen or a hydroxyl group, R ₁ is an alkoxy group having 1 to 36 carbon atoms, and R ₂ is an alkoxy group having 1 to 36 carbon atoms. The manufacturing process check label according to claim 4 , wherein R ₁ or R ₂ is an alkoxy group having 15 to 36 carbon atoms.   The manufacturing process check label according to claim 1, wherein the content of the dye in the polymer composition is 0.01 to 10% by weight.   The manufacturing process check label according to claim 1, wherein the polymer is polyester.   A method for displaying temperature and time history in a manufacturing process of a predetermined article using the manufacturing process check label according to claim 1.