JP6284833B2 - Marking, marking method, and inkjet printer - Google Patents

Description

  The present invention relates to a thermochromic marking that irreversibly develops or changes color when exposed to a certain temperature or higher. Specifically, the present invention relates to a method for forming a thermochromic marking and an apparatus used for forming the same.

  There are many products such as pharmaceuticals and frozen foods that need to be refrigerated or stored frozen. These products manufactured at the factory are transported to customers such as hospitals, supermarkets, wholesalers, etc. as they are with vehicles that have a cold-retaining function, but some are temporarily stored in the warehouse in the factory and then transported to the customers. The

  Here, when transported or stored, if the product is not managed at an appropriate temperature, the product will be altered. For example, in the case of pharmaceuticals, there are problems that the efficacy is reduced and harmful substances are generated or increased. In the case of frozen foods, there are problems of alteration such as taste, flavor deterioration and spoilage due to denaturation.

  Regarding medicines, the EU has implemented the Good Distribution Practice of Medical Products for Human Use (2013 / C 68/01), which has established appropriate temperature management, etc. since September 2013. As a result, temperature management in containers for transporting pharmaceuticals has been carried out by real-time management using a temperature sensor and recording using a pen recorder or the like. However, even if a large number of goods are transported from the factory, this kind of management can be done, but if it is transported from a wholesaler to a hospital etc. with one to several pieces of management, strict management is so far This is a difficult situation in terms of both personnel and costs.

  Therefore, irreversible thermochromic marking that causes irreversible coloring when a certain temperature (storage upper limit temperature) is reached has been studied. This is a marking that does not develop color when the storage temperature is appropriate, but develops color when the storage temperature exceeds an appropriate value, and the color development does not disappear even when cooled again. By performing such marking, a history exceeding the proper storage temperature remains, and it is possible to determine the cause when the product is denatured.

  As such a marking, Patent Document 1 describes a thermochromic marking in which a color developer layer and a color former layer are brought into contact with each other and become irreversibly colored when a certain temperature or higher is reached.

Japanese Patent Laid-Open No. 10-287863 JP 2009-196208 A

  The technique of Patent Document 1 simply indicates that the upper limit temperature of storage has been exceeded by irreversible color development, and there was no idea of adding other information. However, if the color former layer can be formed with fine dots, etc., it will be possible to develop colors in the form of symbols and letters, so not only the management status of storage temperature due to color development is known, but also the name of the factory that manufactured the product, Information such as the production number and the production date can also be entered as hidden characters. In addition, since information such as a bar code and a matrix type two-dimensional code can be printed, logistics can be easily managed by providing a reader for reading the information at a product delivery place.

  One aspect of the present invention is a method of forming a marking that develops a color when the temperature is higher than a specified temperature on a substrate. This method includes a first step of forming a first member containing a developer or a color former on a substrate, a second step of forming a barrier layer that covers the first member, and a developer on the barrier layer. And a third step of forming a second member including a colorant or a color former different from the first member. At least one of the first step and the third step includes a step of forming a liquid containing a developer or a color former into droplets, and a step of depositing the liquid droplets on the substrate or the barrier layer. Have.

  Another aspect of the present invention includes an ink container that stores ink, an inkjet head that ejects ink droplets, and an ink supply path that supplies ink from the ink container to the inkjet head. This is an ink jet printer that forms an arbitrary pattern on a substrate. The printer has a cooling device that can be cooled to maintain at least a portion of the ink at a temperature below 15 degrees Celsius.

  Another aspect of the present invention is a marking formed on a substrate. This marking consists of a developer layer, a barrier layer, and a color former layer formed on the substrate. The barrier layer has a configuration in which the developer layer and the color former layer are kept in non-contact at the first temperature, and the developer layer and the color developer layer are brought into contact at the second temperature. At least one of the developer layer and the color developer layer is formed in a plurality of dot shapes, and a predetermined pattern is formed by the plurality of dots. Then, when the developer layer and the color former layer are in contact with each other at the second temperature, the color former layer is colored, and a predetermined pattern is visualized.

  Here, the dot shape means that the layer has an intermittent structure in the horizontal direction. As a typical example of drawing a pattern using an ink jet printer, the dots are approximately circular with a diameter of 0.3 to 0.5 mm, and the dot interval is 0.3 to 0.5 mm. However, in the present invention, the shape, size, and interval of the dots are not limited to this.

  In the present specification and the like, notations such as “first”, “second”, and “third” are attached to identify the components, and do not necessarily limit the number or order.

  In the present specification, the color former is colorless or light-colored when it comes into contact with a product such as a pharmaceutical product or frozen food (hereinafter referred to as a printing substrate), and develops color upon contact with an acidic or basic chemical. Defined as a drug. Further, in this specification, the developer is defined as a colorless or light-colored drug that exhibits acidity or basicity.

  In the present invention, when the barrier layer reaches a temperature or higher, the developer and the color former come into contact with each other by melting or softening, and the color development of the color former starts.

  The layer structure may be the order of the developer, the barrier layer, and the color developer on the surface of the printing equipment, or the order of the color developer, the barrier layer, and the developer.

  According to the present invention, it is possible not only to know the management state of the storage temperature by color development, but also to add other additional information.

It is sectional drawing which shows the formation method of the marking of this invention. It is sectional drawing which shows the formation method of the marking of this invention. It is a sectional structure figure of marking. It is a sectional structure figure of marking of the present invention. It is a sectional structure figure of marking of the present invention. It is sectional drawing which shows the formation method of the marking of this invention. It is sectional drawing which shows the formation method of the marking of this invention. It is a sectional structure figure of marking of the present invention. It is a sectional structure figure of marking of the present invention. It is a schematic diagram of the barrier layer forming mechanism of the marking forming apparatus of the present invention. It is a schematic diagram of the developer layer forming mechanism of the marking forming apparatus of the present invention. It is a schematic diagram of the film cross section in which the developer layer of the marking of this invention was formed. It is a schematic diagram of the marking formation apparatus of this invention. It is a schematic diagram of the marking formation apparatus of this invention. It is a schematic diagram of the marking formation apparatus of this invention.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  However, the present invention is not construed as being limited to the description of the embodiments below. Those skilled in the art will readily understand that the specific configuration can be changed without departing from the spirit or the spirit of the present invention.

  In the structures of the invention described below, the same portions or portions having similar functions are denoted by the same reference numerals in different drawings, and description thereof may not be repeated.

  The position, size, shape, range, and the like of each component illustrated in the drawings and the like may not represent the actual position, size, shape, range, or the like in order to facilitate understanding of the invention. For this reason, the present invention is not necessarily limited to the position, size, shape, range, and the like disclosed in the drawings and the like.

  Publications, patents and patent applications cited in this specification form part of the description of the present specification as they are.

1. Marking formation method There are two types of marking.

(1) Method of forming a developer layer, a barrier layer, and a color former layer in this order on the printing substrate First, a developer layer is formed on the surface of the printing equipment. After cooling to the storage temperature, a barrier layer is formed on the developer layer that dissolves or softens when the temperature exceeds a certain temperature. Finally, the color former is printed by a charge control type ink jet printer or the like.

  FIG. 1 shows this formation process and the formation state.

  First, the developer layer 2 is formed on the substrate 1. At the time of formation, it is formed by a method in which a solution in which a developer is dissolved is applied and then dried, or a method in which a porous agent that has absorbed the developer is attached.

  A barrier layer 3 is formed thereon. In forming, a coating method such as roll coating is preferred. The developer layer and the barrier layer are basically formed in a layer having a substantially uniform thickness.

  A color former layer 4 is formed thereon. This is an information display of only a temperature history in a uniform layer structure. Therefore, it is desirable to form fine dots in order to form a large amount of recording information.

  Here, for example, when the barrier layer has a property of being dissolved at 5 ° C., the barrier layer is dissolved at 5 ° C. or higher, the developer layer and the color former having a fine dot structure come into contact with each other, and the color developing layer develops color.

  FIG. 2 shows an example using a film structure.

  As shown in FIG. 2, a film 100 in which the developer layer 2 is formed on the front surface and the adhesive layer 5 is formed on the back surface is formed in advance. The marking of the present invention is completed by pasting this on the substrate 1 and forming the barrier layer 3 and the color former layer 4 thereon. Since the developer 2 can be formed by sticking, there is an advantage that the marking of the present invention can be easily formed. Although not shown in FIG. 2, a film substrate formed of polyethylene, polypropylene, or the like may be present between the developer layer 2 and the adhesive layer 5. In this case, the developer layer 2 is formed on one side of the film substrate, and the adhesive layer 5 is formed on the opposite side.

  FIG. 3 is a view showing another example of the sectional structure of the created marking.

  In FIG. 1, the developer layer 2 is shown covered with the barrier layer 3. Here, as shown in FIG. 3, when the developer layer 2 is larger than the barrier layer 3, if the marking site is rubbed, the color developer layer 4 may come off the barrier layer 3 and adhere to the developer layer 2. There is sex. In that case, there is a risk of color development even if the barrier layer 3 is not dissolved. Therefore, it is desirable that the developer layer 2 is covered with the barrier layer 3, that is, the developer layer 2 is smaller than the barrier layer 3.

  Further, the color former layer 4 may be rubbed with a finger or the like during product transportation and peeled off. In this case, the coloring effect may be lost.

  FIG. 4 is a diagram showing a cross-sectional structure of the marking in consideration of contact of the finger or the like with the marking.

  In the configuration of FIG. 3, there is a possibility that the printed marking portion may be touched during the transportation operation of the product. In this case, the barrier layer is broken and color development occurs. However, it is difficult to completely prevent such a defect because there is a possibility that it is not possible to visually determine where the marking is unless the color is developed. Accordingly, a cover layer 6 may be provided on the color former layer 4 as shown in FIG. The material of the cover layer needs to be transparent or almost transparent in the visible region so that the color of the color developing layer can be visually confirmed.

  FIG. 5 is a view showing another example of the cross-sectional structure of the marking in consideration of the contact of the finger or the like with the marking.

  In order to prevent a finger or the like from coming into direct contact with the color developer layer 4, a method of raising the end of the developer layer 2 as shown in FIG. This can be created by, for example, coating the end portion a plurality of times when applying the developer layer. Such a structure is preferable because the abrasion resistance is improved even when the developer layer 2 is larger than the barrier layer 3.

  Compared to the one with a rectangular cross-section as in (a), the shape to be raised is a structure with slightly reduced corners in that it can disperse energy during rubbing as in (b), A structure in which the corners of the end portions are completely dropped as described above, and a structure in which the cover layer 6 is provided as shown in FIG. Of the four shown here, (d) provided with the cover layer 6 may have a structure most resistant to rubbing. However, since it takes the most labor to form, there is a possibility that the price of the products that form it is limited to those that are somewhat expensive.

  In FIG. 5, the raised portion is a part of the developer layer 2, but from the viewpoint of protecting the color developer layer 4, it is not necessary to be a developer, and any raised portion is sufficient. However, in order to simplify the process, it is preferable to use a developer.

(2) A method of forming a color former layer, a barrier layer, and a developer layer in this order on the printing substrate After forming the color former layer using an electric control type ink jet printer, etc., and cooling to the storage temperature, a certain amount A barrier layer that dissolves or softens when the temperature is exceeded is provided, and then a developer layer is formed.

  FIG. 6 shows a sectional view of the forming process.

  First, the color former layer 4 is formed on the surface of the printing substrate 1. A barrier layer 3 is formed on the color former layer 4 by coating by roll coating or the like. Finally, the developer layer 2 is formed by applying a solution in which the developer is dissolved.

  FIG. 7 shows a cross-sectional view of another forming process.

  As in FIG. 6, the color former layer 4 and the barrier layer 3 are formed.

  Here, a film 101 in which the color developing layer 2 and the adhesive layer 5 are formed on the back surface of the cover layer 6 is used. Since the cover layer 6 of the film 101 is the outermost surface, the film 101 is preferable in that it becomes a protective layer for enhancing the abrasion resistance of the marking. In this case, it is desirable that the barrier layer 3 is completely covered with the developer layer 2 and the cover layer 6. Thereby, even if the marking site is rubbed, the film 101 protects the marking, so that it is possible to suppress the problem of color development even if the barrier layer 3 is not dissolved or softened. In this film 101, the film base is used as a cover layer 6 for marking protection.

  When this structure is used, the barrier layer, developer layer, film, etc. that are superimposed on the color forming layer are materials that absorb little in the visible region so that the color developing layer can be recognized when the color develops. It is necessary to choose. In addition, in the case of a material with low transparency and turbidity, light is scattered and it may not be possible to determine the presence or absence of color development. Therefore, a material with low scattering is also desired.

(3) Application of Marking Forming Method By improving the structure of the present invention, it becomes possible to obtain a plurality of temperature history information. Barrier layers having different temperatures for melting or softening are used.

  FIG. 8 is an example of a cross-sectional structure of the marking of the present invention.

  The geometrical configuration of the marking of FIG. 8 is the same as the example of FIG. The difference is that the melting temperature of the barrier layer 3 is different between the plurality of markings 801 and 802. For example, it is assumed that the barrier layer 3a is dissolved at A ° C. and the other barrier layer 3b is dissolved at B ° C. Also assume that B ° C is higher than A ° C. First, the barrier layer 3a is applied on the developer layer 2a. Next, the barrier layer 3b is applied on another developer layer 2b.

  When the product was transported refrigerated, the marking 801 coated with the barrier layer 3a developed color, and the marking 802 coated with the barrier layer 3b did not develop color. You can see that it was placed. Although two types of barrier layer materials are used for the barrier layer 3 in FIG. 8, the storage temperature history can be examined more finely by using another barrier layer material having a different melting temperature.

  FIG. 9 shows another example of the cross-sectional structure of the marking according to the present invention.

  The geometric configuration of the marking in FIG. 9 is the same as the example in FIG. The difference is that the melting temperature of the barrier layer 3 differs between the plurality of markings 901 and 902. For example, it is assumed that the barrier layer 3a is dissolved at A ° C. and the other barrier layer 3b is dissolved at B ° C. Also assume that B ° C is higher than A ° C. First, the barrier layer 3a is applied on a certain color former layer 4a. Next, the barrier layer 3b is applied on another color former layer 4b.

  In the example of FIG. 9 as well, the temperature history can be examined in the same manner as in the example of FIG. In addition, if the types of barrier layer materials having different melting temperatures are increased, the history of storage temperature can be examined more finely.

2. Materials Used for Marking Next, materials for forming the color former layer, the developer layer, and the barrier layer used for the marking of the present invention will be described.

(1) Color former layer material The materials shown here are usually colorless or light-colored by visual observation, but correspond to substances that change color by touching an acidic substance or basic substance and visually develop color. However, here, a substance that is almost colorless or pale in the vicinity of neutrality at a pH of about 5 or more and less than pH 8, and that develops a color at a pH of less than about 5 is referred to as a "substance that develops color by touching an acidic material". A substance that develops color when touched by sexual materials. Depending on the substance, there are compounds that exhibit different colors depending on whether they are acidic, near neutral, or basic, so there are also substances that are listed as both "substances that develop color when they touch acidic materials" and "substances that develop color when they touch basic materials" is there.

  Also, a solid product is desirable in the product storage environment so that it does not flow when the product after the marking is formed is tilted at various angles and stored.

A) Substances that develop color when in contact with acidic materials Examples of such substances include methyl violet carbinol base, malachite green carbinol base, thymol blue, methyl yellow, and methyl orange.

  A substance that develops color when it comes into contact with an acidic substance develops color even when it comes into contact with acidic gas such as carbon dioxide in the air or SOX or NOX. For this reason, even if the color is stored in a temperature region that is not originally colored, the color may be developed, and the original purpose of temperature control may not be achieved. Even when the concentration is low, coloring proceeds when exposed to these acidic gases for a long time.

  Therefore, in order to suppress this problem, it is conceivable to mix a basic polymer in the color former layer when the color former layer comes into contact with an acidic substance. For example, it is preferable to mix a polymer having an amino group in the material of the color former layer. Since the amino group shows basicity, the color former layer material can always be kept basic even after the marking is formed by coexisting a compound having an amino group. For this reason, it becomes possible to suppress the color development by acid gas exposure.

  In this case, if the compound having an amino group is a low crystallinity or amorphous polymer, it is preferable because the color former layer can be formed in a substantially uniformly dispersed state after mixing with the color former layer material. . On the other hand, it is not preferable to use a material with high crystallinity, because when mixed, it tends to phase-separate gradually even if it is nearly uniform.

  As the polymer having an amino group, polyethyleneimine, polyallylamine and the like are suitable.

B) Substances that develop color when touched with basic materials Examples include thymol blue, phenol red, phenolphthalein, naphtholphthalein, cresol red, and alizanin yellow.

(2) Developer layer material The material shown here is an acidic substance or a basic substance, and this is also a product storage environment so that it does not flow when storing the product after forming the marking at various angles. Then, a solid thing is desirable. For example, when the product is stored at room temperature, a solid product is desirable at room temperature (approximately 30 ° C. or less). In addition, it is desirable to be amorphous in order to form a substantially uniform layer structure.

A) Acidic substances Examples of such acidic substances include polymers having a carboxyl group or a sulfonic acid group. Specifically, polyacrylic acid, polymethacrylic acid, polystyrene sulfonic acid, copolymer of styrene and polyacrylic acid, copolymer of methyl acrylate and acrylic acid, copolymer of ethyl acrylate and acrylic acid, acrylic Copolymer of propyl acid and acrylic acid, copolymer of butyl acrylate and acrylic acid, copolymer of hexyl acrylate and acrylic acid, copolymer of octyl acrylate and acrylic acid, methyl methacrylate and acrylic acid Copolymer, Copolymer of ethyl methacrylate and acrylic acid, Copolymer of propyl methacrylate and acrylic acid, Copolymer of butyl methacrylate and acrylic acid, Copolymer of hexyl methacrylate and acrylic acid, Methacrylic acid Copolymer of octyl and acrylic acid, copolymer of styrene and polymethacrylic acid, methyl acrylate and Copolymer of tacrylic acid, copolymer of ethyl acrylate and methacrylic acid, copolymer of propyl acrylate and methacrylic acid, copolymer of butyl acrylate and methacrylic acid, copolymer of hexyl acrylate and methacrylic acid , Octyl acrylate and methacrylic acid copolymer, methyl methacrylate and methacrylic acid copolymer, ethyl methacrylate and methacrylic acid copolymer, propyl methacrylate and methacrylic acid copolymer, butyl methacrylate and methacrylic acid Acid copolymer, hexyl methacrylate and methacrylic acid copolymer, octyl methacrylate and methacrylic acid copolymer, styrene and styrene sulfonic acid copolymer, methyl acrylate and styrene sulfonic acid copolymer, Copolymer of ethyl acrylate and styrene sulfonic acid, propyl acrylate and Tylene sulfonic acid copolymer, butyl acrylate and styrene sulfonic acid copolymer, hexyl acrylate and styrene sulfonic acid copolymer, octyl acrylate and styrene sulfonic acid copolymer, methyl methacrylate and styrene sulfone Copolymer of acid, copolymer of ethyl methacrylate and styrene sulfonic acid, copolymer of propyl methacrylate and styrene sulfonic acid, copolymer of butyl methacrylate and styrene sulfonic acid, hexyl methacrylate and styrene sulfonic acid Examples include copolymers, copolymers of octyl methacrylate and styrene sulfonic acid, polyaspartic acid, polyglutamic acid, and polyvinylphenol.

  In addition, aliphatic carboxylic acids that are solid at room temperature, specifically decanoic acid having a melting point of 30 ° C., and dodecanoic acid, tetradecanoic acid, hexadecanoic acid, octadecanoic acid, etc. having a higher carbon number are also low in crystallinity. Is easy to form. Furthermore, it is more preferable to use a mixture of these dicarboxylic acids because the crystallinity is lowered.

  The dicarboxylic acid having two carboxyl groups has a melting point of 189 to 190 ° C. even with the smallest oxalic acid having 2 carbon atoms, and is solid at room temperature. However, a dicarboxylic acid having a large carbon number is preferred because of its high crystallinity.

  Adipic acid and the like are easily crystallized when the number of carbon atoms is short. Therefore, dicarboxylic acids having a large number of carbon atoms, specifically, sebacic acid having 10 carbon atoms, 12 dodecanoic acids, 14 tetradecanoic acids, 16 hexadecanoic acids and the like can be mentioned. Further, as in the case of carboxylic acid, the use of a mixture of these dicarboxylic acids is more preferred because the crystallinity is lowered.

B) Basic substance Examples of the basic substance include polymers having amino groups such as polyethyleneimine, polyallylamine, chitosan, polylysine, polyarginine, and polyaniline. Also,
Aliphatic diamines that are solid at room temperature, specifically diaminohexane, diaminooctane, diaminodecane, diaminododecane, and the like are also suitable because they are easy to form a developer layer because of their low crystallinity.

  Monoamines are preferred because the melting point does not rise to room temperature or higher unless the carbon number is significantly increased, but those having 14 or more carbon atoms are solid at room temperature. Specific examples include tetradecylamine having 14 carbon atoms and a melting point of 37 ° C., hexadecylamine having 16 carbon atoms, and octadecylamine having 18 carbon atoms.

  By the way, the material of the color former layer is weak in color and may be poor in visibility only when it is brought into contact with an acidic or basic color developer layer. In that case, there is a color former material in which color development is enhanced by the coexistence of moisture. For example, phenolphthalein produces a very light pink color when water is not present together, but a good pink color appears when water is slightly present.

(3) Barrier layer material The material shown here is provided between the developer layer and the color former layer, and acts as a barrier so that they do not contact each other until the specified temperature is reached. In addition, the barrier layer material preferably has a structure having as little acidic groups as carboxyl groups, sulfonic acid groups, and phenolic hydroxyl groups, and basic groups such as amino groups. This is because even if the barrier layer is not softened or dissolved, these acidic groups or basic groups may react with the color former and the color former may be colored.

  Thus, candidate materials for the barrier layer include acidic hydrocarbons, long-chain hydrocarbons that do not contain basic groups, or some branched hydrocarbons. In addition, an alcohol having a long hydrocarbon chain or a branched hydrocarbon chain, a diol, a ketone, an amide having a long hydrocarbon chain or a branched hydrocarbon chain, an ether, an ester, and the like can be given.

  For example, as a structure of the barrier layer material, a material composed of a hydrocarbon having 10 to 18 carbon atoms is used. Or as a structure of barrier layer material, what consists of a 2 or more types of mixture is used among C10-C18 hydrocarbons.

  As hydrocarbons of long or branched hydrocarbon chains or cyclic hydrocarbon chains, decane (-30 ° C), 2-methylnonane (46 ° C), cyclodecane (9 ° C), dodecane (-12 ° C), tetradecane (6 ° C), hexadecane (17 ° C), octadecane (28 ° C) and the like. The parentheses are melting points. Hydroxyl-terminated alcohols or diols include 1,3-propanediol (-59 ° C), 1,4-butanediol (20 ° C), 1,6-hexanediol (40 ° C), 1,2-octane Diol (37 ° C), 1-octanol (-16 ° C), 1-decanol (6 ° C), 1-dodecanol (24 ° C), 1,2-dodecanediol (58 ° C), 1,12-dodecanediol (82 ° C), 5,6-dodecanediol (47 ° C), 1-tetradecanol (38 ° C), 2-tetradecanol (34 ° C), 7-tetradecanol (42 ° C), 1-hexadecanol ( 50 ° C). Materials with a ketone structure include 2-octanone (-16 ° C), 3-octanone (-23 ° C), 2-decanone (3 ° C), 2-dodecanone (-20 ° C), 3-dodecanone (-19 ° C) ), 2-tetradecanone (35 ° C), 3-tetradecanone (34 ° C), 3-hexadecanone (43 ° C), propiophenone (18 ° C), butyrophenone (12 ° C), isobutyrophenone (1 ° C), hexanophenone (26 ° C.), octanophenone (22 ° C.), decanophenone (35 ° C.), dodecanophenone (45 ° C.), tetradecanophenone (53 ° C.), hexadecanophenone (59 ° C.) and the like. The temperature of the melting point is shown in parentheses.

The selection of these barrier layer materials depends on the storage upper limit temperature of the product to be marked.
For example, in the case of frozen food made from meat, since it is around -16 ° C, a compound such as 1-octanol or 2-octanone having a melting point of -16 ° C is provided in the barrier layer. When seafood is stored at a slightly lower temperature, 3-octanone with a melting point of −23 ° C. is a candidate. In the case of carbohydrate-based products, dodecane with a melting point of −12 ° C. is a candidate for storage at a slightly higher temperature. These barrier materials can be used alone, but by mixing a compound having a higher melting point than that, the crystallinity is lowered and becomes amorphous, so the barrier layer becomes dense and the color former. This is preferable because the shielding property between the layer and the developer layer is improved.

  In particular, the amorphousness is increased by mixing compounds having similar structures. For example, by adding tetradecane having a melting point of 6 ° C. or hexadecane having a melting point of 17 ° C. to dodecane having a melting point of −12 ° C., the barrier layer becomes amorphous, and between the color former layer and the developer layer. Shielding is improved.

  The temperature at which the barrier layer softens when the barrier layer material is a mixture of various substances varies depending on the melting point and the addition rate of the mixed material. For example, when an equal amount of a material a having a high melting point A ° C. and a material b having a melting point B ° C. are mixed in equal amounts, the melting point is approximately between A and B. However, when the difference between the melting points of the two materials is large, specifically, when the temperature is 50 ° C. or higher, the temperature at which the barrier layer softens or dissolves is substantially the same as the melting point of the material with the lower melting point. Further, when materials having low compatibility are used, the temperature at which the barrier layer is softened or dissolved is substantially the same as the melting point of the material having a lower melting point.

  If the product to be marked is a pharmaceutical product requiring storage below 10 ° C, tetradecane with a melting point of 6 ° C, or 1-decanol, or 2-dodecane with a melting point of 3.5 ° C, hexadecane with a melting point of 17 ° C, or a melting point of 19 Add 3-dodecanone at 20 ° C and 2-dodecanone at 20 ° C to adjust the melting point to approximately 10 ° C.

(4) Film material By forming the developer layer on the film, it becomes easy to stick to the product.
For example, as shown in FIG. 2, when a developer layer is first attached to a product, an adhesive layer is formed on the surface of the film where the developer layer is not formed. Thereby, the film having the developer layer can be easily attached to the product. In addition, when the color developer layer and the barrier layer are formed as shown in FIG. 7, when the developer layer is formed, the adhesive for adhering to the product on the same side as the surface on which the developer layer is formed. By providing the layer portion, it is easy to attach the product.

  In particular, in the case of FIG. 7, since the outermost surface is a film, the physical strength of the marking of the present invention is improved, and the outermost film guards even if it is slightly rubbed.

  In the case of FIG. 2, when the color of the film is similar to the color of the color former layer, it is difficult to confirm the presence or absence of color development. Any other color is suitable because it is easy to confirm the presence or absence of color development. In the case of FIG. 7, it is necessary to be substantially transparent in order to confirm the presence or absence of color development.

  The material of the film is preferably a material such as polyethylene or polypropylene because it is inexpensive and can withstand various organic solvents. However, the adhesiveness is difficult because various adhesive materials are repelled. Moreover, since it is a crystalline polymer, when it is thick, the film becomes whitish, light transmittance is lowered, and it is difficult to determine whether or not the marking is colored. Therefore, a polyethylene terephthalate (PET) film is an example of a resin that easily imparts adhesion and transparency in addition to solvent resistance. Since this resin is amorphous, it has high transparency and high solvent resistance, and is insoluble in general-purpose organic solvents such as acetone and alcohol. Moreover, since the critical surface tension is large compared to hydrocarbon resins such as polyethylene and polypropylene, the adhesiveness is excellent.

(5) Cover Layer Material The cover layer 6 shown in FIGS. 4 and 7 is desirably visually transparent or light so that the color of the color former layer can be visually confirmed. Since the human eye is highly sensitive to visible light having a wavelength of 400 to 700 nm, a material having as little absorption as possible in this wavelength region is a candidate for the cover layer material. In order to improve visibility, an amorphous material is preferable to a material having high crystallinity. Specifically, amorphous PET resin, polycarbonate resin, acrylic resin, or the like is preferable to polyethylene or polypropylene, which are crystalline polymers. However, it is possible to use a crystalline resin by improving the light transmittance by forming a thin cover layer.

  In addition, the cover layer material must be a member that does not dissolve the color former layer, the barrier layer, and the developer layer. Furthermore, when the cover layer material is dissolved in an organic solvent, and then applied on the color former layer, barrier layer, and developer layer, and the cover layer is formed, the solvent in which the cover layer material is dissolved is colored. It is necessary to select one that does not dissolve the agent layer, barrier layer, and developer layer.

3. Marking forming apparatus Next, an apparatus for forming a marking according to the present invention will be described.

  An apparatus for forming a marking requires an apparatus for forming a developer layer, an apparatus for forming a barrier layer, and an apparatus for forming a color former layer. In some cases, an apparatus for forming a cover layer is also required.

  When marking, the printed part is not only flat, but in the case of ampoules, it is necessary to print on a cylindrical curved surface.

  Also, when printing on a plurality of objects such as pharmaceutical ampules, printing must be performed at a considerable speed.

  In order to meet the above-described requirements, this embodiment shows an example in which the principle of an ink jet printer is applied as a configuration capable of printing in various shapes at high speed. However, in a normal inkjet printer, the temperature inside the apparatus is as high as 40 to 50 ° C. even when the room temperature is about 20 ° C. due to heat generation from a built-in pump, electronic substrate, and the like. Therefore, even if the ink tank is taken out of the apparatus, the ink may be 20 ° C. or higher.

  For this reason, when the barrier layer is already formed on the object side and printing is performed thereon, it is necessary to manage the temperature of the ink so that the barrier layer is not damaged by the heat of the ink.

  Even when the barrier layer is formed after printing on the object side, the temperature of the ink can be taken into consideration so that the heat of the printed ink does not affect the barrier layer to be formed later. desirable.

  For example, Patent Document 2 discloses a known example for cooling ink. Patent Document 2 shows a configuration in which the temperature of ink is set to a specified temperature (15 to 40 ° C.) in order to maintain print quality. However, for example, the temperature for maintaining the quality of the pharmaceutical is less than 15 ° C., preferably 10 ° C. or less, and the marking needs to be formed below this temperature (ie, the barrier layer needs to be kept below this temperature). For example, in the Japanese Industrial Standard (JIS K0050 chemical analysis method general rules), the cold place is set to 1 ° C to 15 ° C. Although it depends on the type of pharmaceutical, it is ideal if it can be stored at 2 ° C to 8 ° C.

  Further, the temperature for maintaining the quality of the frozen food in the distribution process is 0 ° C. or less, preferably minus 20 ° C. or less, and the marking needs to be formed at this temperature or less. For example, the Japanese Industrial Standard (JIS 9607 Electric Refrigerator and Electric Freezer) defines three types of temperatures of minus 6 ° C., 12 ° C., and 18 ° C. as the temperature of a freezer for home use. Therefore, it is necessary to enable cooling at a temperature lower than the specified temperature of normal printing ink in the apparatus of the present embodiment that can form markings for temperature history management instead of normal printing applications.

  Further, it is desirable that the marking be formed in an environment maintained at a temperature suitable for maintaining the quality of the product. Therefore, the marking forming apparatus of the present embodiment is used in an environment of, for example, 10 ° C. or lower for pharmaceutical products and 0 ° C. or lower for frozen foods.

(1) Apparatus for forming the developer layer and the barrier layer When forming the developer layer, as shown in FIG. 1, when the developer material is applied directly on the substrate of the product, and FIG. As shown in Fig. 5, the apparatus differs depending on the case where a film having a developer layer is applied. Therefore, each will be described.

(A) When a developer is applied FIG. 10 is a schematic diagram of a layer forming mechanism of the marking forming apparatus of the present invention.

  First, the developer 12 is discharged from the opening 11 of the hopper 10 filled with the developer, and is applied onto the substrate 1. The width and thickness of the developer layer 2 are controlled by the size of the opening 11. After the developer layer 2 is applied to a desired length, the developer band is cut with the squeegee 13 by raising the hopper 10.

  Note that the tank of the developer material to be used and general equipment such as a compressor used when the developer material is sent from the tank to the hopper are omitted in this drawing.

  Here, the developer is used in a form dissolved or suspended in some organic solvent. Further, if the barrier layer material is not dissolved, a heating mechanism capable of heating a portion in contact with the barrier layer material such as a hopper is provided. At the time of application, a heating mechanism is operated to dissolve and apply the barrier layer material.

  In addition to the apparatus shown in FIG. 10, a bar coater or an applicator can be formed. However, these can be used for a small lot, but are not suitable for mass production. Shape is preferred.

(B) When a film having a developer layer formed thereon is attached FIG. 11 is a schematic diagram of a developer layer forming mechanism of the marking forming apparatus of the present invention.

  This device configuration consists of a mechanism that cuts the film on which the developer layer is formed at a certain length, a mechanism that affixes the cut film onto a substrate or barrier layer, and a barrier layer that has a certain thickness is applied and formed. And a mechanism for forming the color former layer on the substrate or the barrier layer in the form of droplets of the color former.

  This will be described with reference to FIG. First, the film 100 is pulled out from the cylinder 14 around which the film 100 on which the developer layer 2 is formed is wound, and the film 100 is pasted on the film end pasting site 17 in front of the blade 16 of the rotary cutter 15. The film 100 used the configuration shown in FIG. The rotary cutter is rotated 90 ° counterclockwise, and the film 100 is cut with the blade 18 of the rotary cutter 15. The cut film 100 is affixed to the substrate by lowering the rotary cutter 15 to bring the film 100 into contact with the substrate 1 or by lifting the substrate 1 up and bringing the film 100 into contact with the substrate 1. At this time, the film 100 on the cylinder 14 side is applied to the blade 18 of the rotary cutter 15 by the adhesive layer of the film. In this way, the film 100 can be stuck on the substrate 1 one after another.

  FIG. 12 shows a schematic cross-sectional view of an example of a film on which the color developing layer of the present invention used in FIG. 11 is formed.

  As shown in FIG. 12, the film 100 is provided with an adhesive layer 20 on the back surface of the film base 19 on which the developer layer 2 is formed, so that it can be attached to a product. When this film is wound in a roll shape, the adhesive layer 20 and the developer layer 2 have low releasability and may not be easily peeled off. In such a case, a release film 21 is provided on the adhesive layer 20. As a result, the pressure-sensitive adhesive layer 20 and the developer layer 2 are strongly bonded to each other, and it is possible to prevent a problem that the developer layer 2 is damaged when peeled off. When the release film 21 is provided, for example, in the example of FIG. 11, a process of peeling the release film 21 may be added before the film 100 is attached to the substrate 1. The release film 21 is preferably made of polyethylene or polypropylene having a small critical surface tension, and a thin coating of silicone oil having a polydimethylsiloxane chain as a basic skeleton can further improve the release property. Is preferred.

(2) Apparatus for forming the color former layer The apparatus for forming the color former layer is preferably a solid coating so that the barrier layer can be easily visually observed when it is desired to change the color tone due to the softening or dissolution of the barrier layer. In this case, an apparatus for forming the developer layer is effective.

  If the color tone changes due to temperature rise, if the color can be developed not only simply but also in the form of letters, in addition to the temperature rise, the number of the factory that produced the product, the number of the production line, and the people involved in the production It is also possible to manage the information. In that case, a printing method using a liquid in which a color former is dissolved as an ink is suitable, and one of them is an ink jet printer. The ink jet printer used in this case is preferably a charge control type ink jet printer capable of printing on a non-flat product such as a large surface unevenness or a cylindrical shape.

  FIG. 13 shows a schematic diagram of the printing process by the color former layer forming mechanism of the marking forming apparatus of the present invention.

  Ink pressurized by a pump in the apparatus (not shown in FIG. 13) becomes an ink droplet 22 of a desired size by a vibrator inside the apparatus, is ejected from a nozzle 23, is charged by a charging electrode 24, and then deflected. The direction is controlled by the electrode 25 and land on the substrate 26. The ink that is not printed is collected from the gutter 27 and returned to the ink tank (not shown in FIG. 13). By controlling the flying direction of the ink droplet 22 by the deflection electrode 25, it is possible to control whether or not to form a dot by ink on the printing material. Furthermore, by controlling the relative positions of the nozzle 23 and the printing material 26, an arbitrary pattern can be drawn on the printing material 26 with the ink droplets 22.

  In this case, the color former layer material is dissolved in some organic solvent and printed in a solution state. The viscosity at that time is desirably 5 mPa · s or less. If the viscosity is higher than this, not only is it difficult to eject, but also the ink breakage becomes unstable, and the size of the ink droplets is not constant, so that the dot size formed on the product substrate varies and the printing becomes difficult to see.

  FIG. 14 is a schematic diagram of a color former layer forming mechanism of the marking forming apparatus of the present invention. An ink flow path and a solvent flow path are shown in the form of an ink jet printer.

  The ink jet printer of the present invention comprises a main body 28 and an ink jet head 29 of the ink jet printer.

  In order to control the pressure of the ink droplet 22 discharged from the nozzle 23, the ink supply path 30 is provided with a supply pump 31 and an adjustment valve 32.

  A sub-container 33 that stores ink is disposed in the main body 28. Ink supply is usually performed by the user supplying ink to the sub container 33. The replenished ink passes through a filter or the like (not shown) to remove impurities, and is accumulated in the main container 37. The ink in the main container 37 is supplied to the nozzles 23 through the ink supply path 34 connected to the ink supply path 30. If the remaining amount of ink in the main container is insufficient, the ink in the sub container 33 can be supplied to the nozzles 23.

  In order to collect ink that is not used for printing and is captured by the gutter 27, an ink collection path 35 is connected to the gutter 27, and the ink that is captured by the gutter 27 is collected by the collection pump 36 in the main container 37. The

  The main body 28 is provided with a solvent container 38 for storing an ink solvent. A solvent supply path 40 is connected to the ink flow path switching valve 39 provided in the ink supply path 30 in order to supply the solvent in the solvent container 38 to the nozzles 23. The solvent in the solvent container 38 is supplied to the nozzle 23 via the ink flow path switching valve 39. Further, the solvent in the solvent container 38 is supplied to the main container 37 through a branch path 41 connected to the solvent supply path 40.

  The supply of the solvent from the solvent container 38 to the main container 37 is a mechanism for replenishing the solvent volatilized by the printing operation. The replenishment is automatically performed when the viscosity of the ink in the main container 37 becomes higher than a specified value due to solvent volatilization. In order to measure the viscosity of the ink as needed, a viscosity measuring mechanism (not shown in this figure) is provided in the main container 37.

  In the present embodiment, the sub container 33, the main container 37, and the solvent container 38 are formed of a resin such as polyethylene or polypropylene. In order to store the color former used in this embodiment, it is preferable to use a resin that is more corrosive than a metal.

  In order to return excess ink and solvent supplied to the nozzle 23 to the main container 37, a suction pump 42 is provided, and an ink return channel 43 is connected to the nozzle 23. When ink ejection from the nozzles 23 stops, the solvent in the solvent container 38 is supplied to the nozzles 23 via the ink flow path switching valve 39, and the nozzles 23 are washed. The solvent after washing is returned to the main container 37 by the suction pump. A replenishment path 44 is connected between the ink supply path 30 and the ink recovery path 35, and ink in the sub-container 33 is replenished into the main container 37 via the replenishment path 44. Each channel is provided with an on-off valve (not shown in this drawing) for opening and closing the channel according to the flow of liquid such as ink and solvent in the channel. Further, the various valves 46 provided in the flow path control the liquid conveyance in the direction indicated by the arrow.

  In this embodiment, the color former becomes very small ink droplets 22 and lands on the barrier layer on the printed material 26. Therefore, if the melting point of the barrier layer is not very low, the possibility of dissolving the barrier layer is small. Further, since the ink droplets themselves are cooled due to the vaporization of the solvent contained, the ink droplets that land on the product are cooler than the temperature of the ink inside the ink jet printer.

  However, when frozen at -30 ° C or lower, such as perishable frozen foods containing a high concentration of protein components, the impacted ink droplets dissolve the barrier layer, and the developer layer and the coloring layer come into contact with each other. There is a possibility that color will develop even though it is stored at the specified temperature. Therefore, it is preferable that the color developing agent solution to be printed is cooled as much as possible inside the ink jet printer, so that the risk of softening or dissolving the barrier layer at the time of marking is reduced.

  Therefore, in the present embodiment, the ink flow path and the solvent flow path before the nozzle 23, the various valves, the sub container 33, the main container 37, and the solvent container 38 are cooled. These were put together and the cooling part 45 was enclosed with the dotted line. Since the solvent is supplied from the solvent container to the main container 37 and the like, the stability of the ink is enhanced by cooling the solvent at that time. It is desirable that the cooling temperature be not higher than the temperature at which the barrier layer is dissolved or softened.

  As a method of cooling the cooling portion 45, the refrigerant is supplied to the cooling portion 45 through the refrigerant pipe 142, and the heat is exhausted to the outdoor unit 143 by a known heat exchanger that compresses, liquefies, decompresses, and vaporizes the refrigerant. Alternatively, a Peltier element or the like may be used.

  In the example of FIG. 14, kinetic energy is given to the ink droplet 22 by the pressure of the supply pump 31 and the electrostatic force of the charging electrode 24. As another method, the ink may be ejected from the nozzles by thermal energy generated from the heating element.

  FIG. 15 is a schematic view showing another example of the color former layer forming mechanism of the marking forming apparatus of the present invention. Since the basic configuration is similar to that of FIG. 14, the same components as those of FIG.

  In FIG. 14, the entire main body 28 and a part of the inkjet head 29 are cooled as the cooling portion 45. Although this method can stably cool the whole, the burden on the heat exchanger increases depending on the required temperature and the size of the apparatus.

  FIG. 15 shows a more efficient cooling method. The parts that need to be cooled are tanks that store ink and have a large heat capacity. In particular, the main container 37 is important because it is directly connected to the nozzle 23. In addition, it is desirable to cool the sub container 33 and the solvent container 38 as well.

  The part which becomes a heat source in the apparatus is the pressure pumps 31, 42, 36 and the like installed in the respective flow paths. Since these generate heat, they are preferably insulated or cooled.

  Of the flow paths, the ink supply path 30 that connects the main container 37 and the nozzles 23 has the greatest need for cooling or heat insulation.

  In the example of FIG. 15, a mechanism for cooling at least a part of the liquid or the barrier layer is provided in order to prevent the coloring of the marking during the formation of the marking.

  For this reason, the sub container 33 and the main container 37 are separated by the heat insulating wall 150 and cooled by the heat exchanger. Further, the pressure pumps 31, 42 and 36 are also isolated by the heat insulating wall 151 and cooled by a heat exchanger (not shown). Further, the ink supply path 30 has a heat insulating structure with a heat insulating material.

  Although depending on the cooling temperature of the ink, there is a problem of dew condensation when the difference between the internal temperature of the ink jet printer and the operating environment temperature is large and the humidity of the environment is high. Therefore, there are cases where the housing of the ink jet printer should also have a heat insulating structure. For example, if the operating environment (outside the apparatus) temperature is about 0 ° C. or higher, condensation may occur. If there is a temperature difference between the low-temperature main body containing the ink container and the head, which is the operating environment temperature, a heat insulation wall should be provided at least between the main body and the head to prevent condensation on the head side. That's fine.

  For example, the cooled main body 28 of the inkjet printer is isolated by the heat insulating wall 154. In this specification, heat insulation refers to preventing heat transfer, and examples of efficient heat insulation include a wall structure composed of fiber-based heat insulating materials such as glass wool, and foam-based heat insulating materials such as urethane foam. Wall structure and a wall structure formed of a hollow structure.

  The temperature to be cooled can be determined by calculation based on the size of the device, the material of the device, the specific heat of the ink, the size of the ink droplet, the thickness of the barrier layer on the substrate, and the like.

  Further, for example, while changing the temperature of the main container 37, a trial writing is performed on the barrier layer on the printing material 26, and the temperature control may be performed with a target of the temperature at which printing can be performed satisfactorily. These controls can be executed by inputting a command for controlling the cooling device from the control terminal 152.

In FIG. 15, a cooling member 153 for cooling the printing material 26 itself is provided. If the cooling member 153 and the cooling mechanism on the ink jet printer side are used in combination, the cooling effect is further enhanced. If the barrier layer is not altered or colored by printing, one of the cooling member 153 and the cooling mechanism on the ink jet printer side may be omitted.
(3) Device for forming the cover layer The cover layer dissolves resin in some organic solvent, and the solution is poured onto the marking using a dispenser or the like. Thereafter, the cover layer can be formed by drying and volatilizing the organic solvent contained therein. Further, it can be formed by a general method such as photocuring using energy such as light.

According to the configuration of the embodiment as described above, it is possible to form a marking even on a non-flat member at high speed.
Specific examples of the present invention are shown below.

(1) Marking formation process Polyacrylic acid (10 g) with an average molecular weight of 250,000 as a developer material is mixed with water (190 g) and stirred with an overhead stirrer while heating to about 60 ° C to dissolve the polyacrylic acid. 5% by weight polyacrylic acid aqueous solution is prepared. This is filled in the apparatus shown in FIG. 10, and applied to a PET film having a thickness of 125 μm and an adhesive layer and a release film on the back surface so that the solution thickness is about 40 μm. After coating, the developer is dried at 60 ° C. for 8 hours, and a developer layer made of polyacrylic acid having an average thickness of 2 μm is formed on the PET film. The PET film is attached to a pharmaceutical paper package using the apparatus shown in FIG.

  Polyacrylic acid is an acidic polymer having a carboxyl group.

  Next, cyclodecane having a melting point of 9 ° C. and tetradecane having a melting point of 6 ° C. are put into a glass container of the same weight, and stirred and mixed with an overhead stirrer to prepare a barrier layer material. When the melting point of the prepared barrier layer material was examined, it was about 8 ° C. This is filled in the apparatus shown in FIG. 10 and applied onto a PET film on which a developer layer formed on a pharmaceutical paper package is formed. The average thickness of the barrier layer after application is 40 μm.

  The room temperature during application is controlled to 5 ° C. or lower. The surface temperature of a pharmaceutical paper package with a PET film with a developer layer attached is also controlled to 5 ° C or less. Thus, a barrier layer is formed on the developer layer.

  Next, a color former layer is formed. Malachite green carbinol base (10 g) as a color former material is dissolved in 190 g of 2-butanone to prepare a 5 wt% 2-butanone solution of malachite green carbinol base. This solution is filled in the ink jet printer shown in FIG. After cooling the cooling portion 45 of the inkjet printer to 0 to 5 ° C., “123456789” is printed numerically on the barrier layer. Thus, the thermochromic marking of the present invention is completed.

  In this state, the number “123456789” is not visually recognized.

  Malachite green carbinol base is light brown in the state of 2-butanone solution, but when it comes into contact with an acidic substance, it turns dark green.

(2) Thermochromic confirmation experiment Transfer the paper package of the medicine for which thermochromic marking has been completed to a room at room temperature of 25 ° C. Then, about 1 minute after the transfer, the number “123456789” appeared in green in the part where the thermochromic marking was formed. I returned to the room at room temperature 5 ° C again, but the numbers did not disappear.

  When the thermochromic marking portion was analyzed, the barrier layer was dissolved, and it was determined that the malachite green carbinol base and the polyacrylic acid were in contact with each other and exhibited a green color.

  As mentioned above, the function of the irreversible thermochromic marking of this invention was confirmed.

  This is basically the same method as in the first embodiment. However, as the barrier layer material, cyclodecane having a melting point of 9 ° C. and 1-decanol having a melting point of 6 ° C. are used in the same weight. A thermochromic marking was formed on a pharmaceutical paper package by the same process as in Example 1 except for the barrier layer material. When the melting point of the prepared barrier layer material was examined, it was about 7 ° C.

  This is transferred to a room temperature of 25 ° C. as in Example 1. Then, about 1 minute after the transfer, the number “123456789” appeared in green in the part where the thermochromic marking was formed. I returned to the room at room temperature 5 ° C again, but the numbers did not disappear.

  As mentioned above, the function of the irreversible thermochromic marking of this invention was confirmed.

(1) Marking formation process Polyacrylic acid (10 g) with an average molecular weight of 250,000 as a developer material is mixed with water (190 g) and stirred with an overhead stirrer while heating to about 60 ° C. Polyacrylic acid is dissolved to prepare a 5 wt% aqueous solution. This is filled in the apparatus shown in FIG. 10 and applied to a PET film having a thickness of 125 μm and an adhesive layer and a release film on the back surface so that the solution thickness is about 40 μm. After coating, the developer is dried at 60 ° C. for 8 hours, and a developer layer made of polyacrylic acid having an average thickness of 2 μm is formed on the PET film. The PET film is attached to a frozen food PET film package using the apparatus shown in FIG.

  Next, 1-octanol having a melting point of −16 ° C. and 2-dodecanone having a melting point of −20 ° C. are put into a glass container of the same weight, and stirred and mixed with an overhead stirrer to prepare a barrier layer material. When the melting point of the prepared barrier layer material was examined, it was about -19 ° C. This is filled in the apparatus shown in FIG. 10 and applied onto a PET film on which a developer layer formed on a pharmaceutical paper package is formed. The average thickness of the barrier layer after application is 40 μm.

  The room temperature during application is controlled to -20 ° C or lower. The surface temperature of a frozen food PET film package to which a PET film with a developer layer is attached is also controlled to -20 ° C or lower. Thus, a barrier layer is formed on the developer layer.

  Next, a color former layer is formed. Malachite green carbinol base (10 g) is dissolved in 190 g of 2-butanone to prepare a 5 wt% 2-butanone solution of malachite green carbinol base. This solution is filled in the ink jet printer shown in FIG. After cooling the cooling portion 45 of the ink jet printer to −5 to 0 ° C., “123456789” is printed numerically on the barrier layer. Thus, the thermochromic marking of the present invention is completed.

  In this state, the number “123456789” is not visually recognized.

  Ideally, the cooling portion 45 of the ink jet printer is desirably −20 ° C. or lower, but the thermochromic marking of the present invention can be formed even at −5 to 0 ° C. as in this embodiment. This is because the amount of malachite green carbinol-based 5 wt% 2-butanone solution that lands on the barrier layer during printing is small, and does not have enough heat to dissolve the barrier layer. Moreover, since the heat of vaporization when 2-butanone volatilizes after landing on the barrier layer is taken away from the barrier layer, it is rather cooled slightly. However, when the temperature exceeds 0 ° C., when the barrier layer of this embodiment is used, the barrier layer starts to dissolve slightly. Therefore, under the conditions of this embodiment, the cooling portion of the ink jet printer needs to be 0 ° C. or lower.

(2) Thermochromic confirmation experiment Move the PET film package of frozen food that has completed thermochromic marking into a room at room temperature of 5 ° C. Then, about 1 minute after the transfer, the number “123456789” appeared in green in the part where the thermochromic marking was formed. I returned to the room at room temperature -20 ℃ again, but the numbers did not disappear.

  When the thermochromic marking portion was analyzed, the barrier layer was dissolved, and it was determined that the malachite green carbinol base and the polyacrylic acid were in contact with each other and exhibited a green color.

  From the above, it was confirmed that the function of the irreversible thermochromic marking of the present invention is applicable to frozen foods.

  This is basically the same method as in the first embodiment. However, polyethyleneimine having an average molecular weight of 70,000 was used as the developer material instead of polyacrylic acid having an average molecular weight of 250,000, and phenolphthalein was used as the color former material instead of malachite green carbinol base. A marking was formed in the same manner as in Example 1 except for the developer and the color former.

  Polyethyleneimine is a basic polymer having an amino group in the molecule. Phenolphthalein develops a pink color upon contact with a basic substance.

  Next, when the marking-formed paper package was moved from a room temperature of 5 ° C. to a room of 25 ° C., about 1 minute later, a pink number “123456789” appeared in the marking-formed portion. I returned to the room at room temperature 5 ° C again, but the numbers did not disappear.

  From the above, it was confirmed that an irreversible thermochromic marking can be formed by considering a color former even when a basic substance is used instead of an acidic substance as a developer.

  Form thermochromic markings at two locations in the same paper package. One place forms the marking shown in Example 1, and the other place forms the marking shown in Example 3.

  When this paper package was moved from the room at -20 ° C to the room at 5 ° C, the marking formed by the method shown in Example 3 showed the green number "123456789". Numbers did not appear on the formed markings.

  Further, when this paper package was moved to a room at 25 ° C., the green number “123456789” appeared on the marking formed by the method shown in Example 1.

  Thus, it was confirmed that by using barrier layers having different melting points, thermochromic markings capable of controlling color development at different temperatures can be formed.

  This is basically the same method as in the first embodiment. However, as a color former material for forming the color former layer, malachite green carbinol base (10 g) is dissolved in 190 g of 2-butanone instead of 5 wt% 2-butanone solution of malachite green carbinol base, malachite green carbinol is used. A 5 wt% solution of malachite green carbinol base in which base (10 g) and polyethyleneimine (2 g) were dissolved in a mixture of 100 g of acetone and 88 g of ethanol was used. A thermochromic marking is formed in the same manner as in Example 1 except for the color former material.

  Polyethyleneimine used here is a basic polymer having many basic amino groups in its structure.

  The paper package in which the thermochromic marking is formed in Example 1 is referred to as package 1, and the paper package in which the thermochromic marking is formed in this example is referred to as package 2. These packages were left in an atmosphere with a nitrogen dioxide concentration of 0.6 ppm, an air temperature of 30 ° C., and a relative humidity of 60%, and were removed after 3 days. Then package 1 had a green number "123456789". However, package 2 had no green numbers. Nitrogen dioxide combines with moisture and becomes nitric acid, so the atmosphere is acidic. Therefore, in package 1, the malachite green carbinol base on the surface of the marking has changed to a green chemical structure, and the green number “123456789” appears. However, in package 2, the coexisting basic polyethyleneimine is considered to suppress the reaction of malachite green carbinol base to a green chemical structure even in contact with acidic gas.

  Since the concentration standard of nitrogen dioxide in the atmosphere is 0.06ppm or less, 0.6ppm in this experiment is harsh compared to the normal environment. Therefore, although it is unlikely that the marking on the package 1 will be colored erroneously by exposure to an acidic gas so that it cannot be practically used, it is considered effective to add a basic polymer for the storage stability of the marking. .

  In the above description, the color forming effect can be obtained even if the film structures of the color former layer and the developer layer are interchanged. However, at present, the color former is nearly 100 times more expensive than the developer. Therefore, the developer has a uniform layer, and the marking is formed with the color former as a dot structure, so that the economical effect of saving the consumption of the color developer is great. When a configuration such as a gutter 27 for collecting unused ink is added as in the ink jet printer described in the embodiment of FIGS. 14 and 15, it is possible to further save the color former.

  The present invention is not limited to the embodiments described above, and includes various modifications. For example, a part of the configuration of one embodiment can be replaced with the configuration of another embodiment, and the configuration of another embodiment can be added to the configuration of one embodiment. Moreover, it is possible to add / delete / replace the configurations of the other embodiments with respect to a part of the configurations of the embodiments.

1… Base material
2 ... Developer layer
3… Barrier layer
4 Color former layer
6… Cover layer
10 ... Hopper
11 ... Opening
12 ... Developer
13 ... Squeegee
14 ... Cylinder
15 ... Rotating cutter
16 ... blade
17 ... Attached part of film edge
18 ... Rotating cutter blade
19 ... Film substrate on which a developer layer is formed
20… Adhesive layer
21 ... release film
22 ... Ink drops
23 ... Nozzle
24… Charging electrode
25 ... Deflection electrode
26 ... Substrate
27 ... Gutter
28… Inkjet printer body
29… Inkjet head
30 ... Ink supply path
31 ... feed pump
32 ... Control valve
33 ... Sub container
34 ... Ink supply path
35 ... Ink collection path
36 ... Recovery pump
37 ... Main container
42… Suction pump
45 ... Cooling part

Claims (8)

In the method of forming a marking that develops color when the temperature exceeds the specified temperature on the substrate,
A first step of forming a first member containing a developer or color former on the substrate;
A second step of forming a barrier layer covering the first member;
A third step of forming, in the barrier layer, a second member that includes a developer or a color former different from the first member,
At least one of the first step or the third step is:
Forming liquid droplets containing the developer or color former;
Depositing the liquid droplets on the substrate or barrier layer;
Have
The marking method, wherein the second step and the third step are performed under an environmental temperature of 10 degrees Celsius or less. As the color former, a substance that changes its structure by touching an acidic substance or a basic substance and visually develops color is used.
A solution containing the color former is used as the liquid.
The marking method according to claim 1. The second step and the third step are performed under an environmental temperature of 0 degrees Celsius or less.
The marking method according to claim 1. In the marking formed on the substrate,
The marking consists of a developer layer, a barrier layer, and a color former layer formed on the substrate,
The barrier layer has a configuration in which the developer layer and the color developer layer are kept in non-contact at a first temperature, and the developer layer and the color developer layer are brought into contact at a second temperature. If it exceeds, it will melt,
At least one of the developer layer and the color developer layer is formed in a plurality of dot shapes, and a predetermined pattern is formed by the plurality of dots,
When the barrier layer melts at a temperature exceeding 10 ° C. which is the second temperature, the color former layer develops color when the developer layer and the color former layer are in contact with each other, and the predetermined pattern is visualized. Characteristic marking. The marking according to claim 4,
The developer layer is formed on the substrate,
The barrier layer is formed on the developer layer,
The color former layer is formed on the barrier layer,
The marking, wherein the developer layer, the barrier layer, and the color developer layer are covered with a cover layer. The marking according to claim 4,
The marking, wherein the developer layer is formed of a film having an adhesive layer on the back surface and a layer made of the developer on the surface.   The marking according to claim 4, wherein the barrier layer contains at least one hydrocarbon having 10 to 18 carbon atoms.   The marking according to claim 4, wherein a basic polymer is mixed in the color former layer when the color former layer is a substance that develops color when contacted with an acidic substance.

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