JP4440627B2 - Laminated body with indicator for heat treatment, and packaging body using the same - Google Patents

Description

  The present invention relates to a laminate with a heat treatment indicator, and a packaging body using the same, and more specifically, it is excellent in visibility of presence or absence of boil sterilization and retort sterilization treatment, heat resistance, solvent resistance, and water resistance. The present invention relates to a laminate with a heat treatment indicator that can reduce the amount of waste of the heat treatment indicator ink composition and is excellent in terms of environment and cost, and a package using the same.

Conventionally, in order to fill and package various articles, plastic substrates, paper substrates, metal foils, etc. are used, and these are arbitrarily laminated, and various packaging materials have been developed and proposed. Yes.
These packaging materials are usually provided with a heat seal layer in the innermost layer, the heat seal layers are opposed to each other, and the peripheral edges thereof are heat sealed. From the opening of the packaging container, for example, filled with various contents such as food and drink, pharmaceuticals, cosmetics, detergents, chemicals, miscellaneous goods, etc. We are manufacturing packaging products.
As a packaging bag that can withstand the conventional boil sterilization treatment, for example, a stretched polyester film, a stretched nylon film, or a stretched polypropylene film that can withstand heat treatment of the boil treatment is used. If necessary, a pattern printing layer is provided and aluminum is used as a barrier layer. Foil and heat-seal layer unstretched polypropylene film, unstretched linear low-density polyethylene film laminated with an adhesive for dry lamination as a packaging material, and the flow direction of the laminated film is top and bottom A four-side seal pouch or a sliding pouch having a bottom is well known.
Conventional boil processing pouches are made by using the laminated film to make a bag and filled with contents such as raw noodles, then heat-sealing the opening and packaging moisture-containing foods or chemicals. , 98 ° C. to 100 ° C., time, 20 to 60 minutes, preferably about 30 minutes around the boil sterilized packaging product can be produced.
The above-mentioned retort pouch is generally used to produce a sealed package by closing the mouth of a container filled with a prepared material while evacuating the air as much as possible and sealing the mouth part while melting the plastic by heating. Then, the sealed package is used, for example, using a normal retort kettle, for example, temperature, 110 ° C. to 140 ° C., preferably around 120 ° C., pressure, 100 kPa to 300 kPa. A retort-treated packaged product by a method such as retort sterilization by a method of heat and pressure treatment at about 180 kPa, preferably about 20 to 60 minutes, preferably about 30 minutes. It is something that can be done.
Therefore, it is difficult to visually confirm whether the contents are boiled or retorted from the exterior of the packaging container.
Conventionally, as a method for confirming the processing conditions for boil sterilization and retort sterilization, if the heating is performed for a certain period of time at a specified temperature in the presence of water vapor, the color is clearly changed, and ink indicating that the heating has been performed under the specified conditions is performed using gravure There is a method of printing on the outer surface of a packaging container with an ink jet printer.
Compared to the gravure printing method, the method of printing on the outer surface of a packaging bag with an ink jet printer can print variable information such as the serial number, date of manufacture, and manufacturing machine that differs for each packaging bag. By printing variable information for each bag, it is very useful because product information can be traced over all processes such as processing, manufacturing, and distribution.

As the ink used in the above-described ink jet printer, for example, a wet heat discolorable ink composition for ink jet printers containing methyl yellow (dye), an organic acid and / or a metal salt thereof, and a conductive substance is provided. A technique is disclosed (for example, Patent Document 1).
In addition, a technique is disclosed that provides an ink composition for an ink jet printer that changes color due to a temperature history, characterized in that the dye contained in the ink composition sublimes and changes color upon heating (for example, Patent Document 2). ).

Japanese Patent Laid-Open No. 4-1280 JP-A-8-3494

However, in the wet heat discoloration ink composition for an ink jet printer of Patent Document 1, the color changes just by touching hot water of about 50 degrees in the pre-process of the boil sterilization and retort sterilization processes. There is a problem that the ink composition cannot be used for confirming the presence or absence of the boil sterilization and retort sterilization performed in the above.
Moreover, in the ink composition for inkjet printers of Patent Document 2, even when boil sterilization or retort sterilization is performed at 100 degrees or more, the dye is not sublimated by heating in the formation portion of the ink composition, and the color may not change. There is a problem that there is.
In addition, the conventional wet heat discoloration ink composition for inkjet printers is formed on the outer surface of the packaging bag, so the printed part may be partially removed by rubbing or the like, or the printed part may be easily wiped with a solvent or the like. There is a risk that the variable information that has been printed is easily tampered with.
Furthermore, in order to prevent falsification of variable information, when laminating a resin film on the printing part, a part of the ink composition is dissolved by the solvent used to bond the layers and the printing part is blurred. Therefore, there is a problem that variable information cannot be read.
In addition, the conventional ink composition for gravure printing is not dissolved by the solvent used for the adhesive, but it is difficult to maintain the quality if the remaining ink remaining in the ink pan after printing is used again. There is a disadvantage that there is an economic loss such as disposal of used ink, and the manufacturing unit cost of the printed packaging material is increased accordingly.
In addition, since the indicator composition according to the present invention has the property of being discolored by heat, if the indicator composition is left in the ink pan, it can be mixed into the next item of ink until the next item is printed, Discoloration due to heat is conspicuous and cannot be used as a product. For this reason, when replacing the ink in the next item, the ink pan must be carefully washed, and in the case of multi-product and small-lot production, there is a disadvantage that workability is deteriorated.

  The object of the present invention is excellent in the visibility of presence / absence of boil sterilization and retort sterilization treatment, heat resistance, solvent resistance, water resistance, and it is difficult to modify the display after printing by rubbing the outer surface. Reduces economic loss such as ink disposal, is excellent in cost and environment, shortens switching work time, reduces work load, and has a laminate with a heat treatment indicator that can be used for multi-product small lot production, and It is to provide a package using the same.

  Therefore, in order to solve the above problems, the laminate with an indicator for heat treatment of the present invention is a laminate in which a base film layer and a heat seal layer are sequentially laminated via an adhesive layer, and a pigment and a synthetic resin The indicator ink composition for heat treatment which contains a binder consisting of the above and changes color irreversibly by heating is formed on the laminate surface side of the base film layer.

  The indicator ink composition for heat treatment is formed by a print head of an injection printer.

  In the laminate with an indicator for heat treatment of the present invention, the pigment is a pigment composed of a bismuth compound and a sulfur compound.

  The laminate with a heat treatment indicator of the present invention is characterized in that a medium layer and / or a white ink layer is formed by overprinting on the heat treatment indicator ink composition.

  Moreover, the package with a heat treatment indicator according to the present invention is formed using the above-mentioned laminate with a heat treatment indicator.

  The laminated body with an indicator for heat treatment of the present invention and a package using the same can print variable information that differs for each package, so that product information can be tracked throughout processing, manufacturing, and distribution processes. Yes, with excellent visibility of boil sterilization and retort sterilization, heat resistance, solvent resistance, water resistance, variable information is not printed on the outer surface, and printing is performed by laminating at least one layer on the printing part. It is difficult to change the variable information by rubbing the outer surface after the display, etc., reducing economic loss such as disposal of residual ink, excellent cost and environment, and switching time Shortening and work load reduction are possible, and it has the advantage of being able to handle high-mix low-volume production.

Hereinafter, embodiments of the present invention will be described in more detail with reference to the drawings.
FIG. 1 is a cross-sectional view showing a layer configuration example of a laminate with a heat treatment indicator of the present invention, and FIG. 2 is a cross-sectional view showing a layer configuration example of a laminate with a heat treatment indicator of another embodiment of the present invention. FIG. 3 is a cross-sectional view showing an example of the layer structure of a laminate with a heat treatment indicator according to still another aspect of the present invention, and FIG. 4 shows the layer structure of the laminate with a heat treatment indicator according to still another aspect of the present invention. It is sectional drawing which shows an example, FIG. 5 is a perspective view which shows an example of the packaging container using the laminated body with a heat processing indicator of this invention, FIG. 6 uses the packaging container shown in FIG. It is a perspective view which shows an example of the package body which filled and packaged the contents.

  As shown in FIG. 1, the laminate with a heat treatment indicator of the present invention is a laminate in which at least a base material layer 1 and a heat seal layer 2 are sequentially laminated via an adhesive layer 3. On the back surface of the material layer 1, a heat treatment indicator ink composition 4 containing a pigment and a binder made of a synthetic resin and irreversibly color-changing by heating is formed by a print head of an injection printer. The material layer 1 / the indicator ink layer 4 for heat treatment / the adhesive layer 3 / the heat seal layer 2 is used.

  As shown in FIG. 2, the laminate with a heat treatment indicator according to another aspect of the present invention is a laminate in which at least a base material layer 1 and a heat seal layer 2 are sequentially laminated via an adhesive layer 3, On the back surface of the base material layer 1 is formed an indicator ink composition for heat treatment that contains a pigment and a binder made of a synthetic resin and changes color irreversibly by heating, and further, a medium layer, And / or white ink layer 5 is formed by overprinting, layer structure, substrate layer 1 / indicator layer for heat treatment 4 / medium layer, and / or white ink layer 5 / adhesive layer 3 / heat seal layer 2.

  As shown in FIG. 3, the laminate with a heat treatment indicator of another aspect of the present invention includes at least a base material layer 1 and a barrier layer such as an aluminum foil or an inorganic oxide vapor deposition film layer as an intermediate layer 6, A laminate in which the heat seal layer 2 is sequentially laminated via the adhesive layer 3, and contains a pigment and a synthetic resin binder on the back surface of the base material layer 1, and changes color irreversibly by heating. The indicator ink composition for heat treatment is formed, and the medium layer and / or the white ink layer 5 is further formed thereon by overprinting, and the layer structure, base material layer 1 / heat treatment indicator ink layer 4 / The medium layer and / or the white ink layer 5 / adhesive layer 3 / intermediate layer 6 / adhesive layer 3 / heat seal layer 2 are used.

  As shown in FIG. 4, the laminate with a heat treatment indicator of still another aspect of the present invention is a laminate in which at least a base material layer 1 and a heat seal layer 2 are sequentially laminated via an adhesive layer 3. Then, a medium layer and / or a white ink layer 5 is formed on the surface of the base material layer 1 and contains a pigment and a binder made of a synthetic resin. The color changes irreversibly by heating. The layer 4 made of the indicator ink composition for heat treatment is overprinted, and the surface film layer 13 is further laminated thereon via the adhesive layer 3, and the layer structure, surface film layer 13 / adhesive layer 3 / heat treatment The indicator ink layer 4 / medium layer and / or the white ink layer 5 / base material layer 1 / adhesive layer 3 / heat seal layer 2 are used.

  As shown in FIG. 5, the packaging container according to the present invention overlaps the heat seal layers of the laminate with a heat treatment indicator according to the present invention so as to face each other, and further, the end portion around the outer periphery thereof. Heat seal is provided to provide a seal.

  As shown in FIG. 6, the packaging body according to the present invention is filled with the contents from the upper opening of the packaging container shown in FIG. 5, and thereafter, the opening 7 is heat sealed to close the upper end sheet. -The package part formed by using the packaging container concerning this invention can be manufactured by forming the lug part 11. FIG.

As the base material layer 1 of the present invention, when constituting a packaging container, it becomes a basic material, so that impact resistance and heat for protecting the packaging material and contents from physical impact from outside after packaging. It is possible to use a resin film or sheet having heat resistance that can withstand sealing and printability.
Specifically, for example, polyester resin, polyamide resin, polyaramid resin, polyolefin resin, polycarbonate resin, polystyrene resin, polyacetal resin, fluorine resin, etc. A resin film or sheet, or the like can be used.
As the resin film or sheet, any of an unstretched film or a stretched film stretched in a uniaxial direction or a biaxial direction can be used. The thickness of the film is about 5 to 100 μm, preferably about 10 to 50 μm.
Further, if necessary, a metal such as aluminum or an inorganic material such as aluminum, alumina oxide or silicon oxide may be vapor-deposited on these base films.
In the present invention, a polyester elastomer is blended with a polyethylene terephthalate film having excellent ink adhesion in order to form a heat treatment indicator ink layer that is inferior in ink adhesion to that of a normal printing ink. It is preferable to use a resin film.
If necessary, for example, a desired printing pattern such as a character, a figure, a symbol, a pattern, or a pattern may be subjected to surface printing or back printing with a normal printing ink.

The indicator ink layer 4 for heat treatment is an ink that changes color irreversibly at a set critical temperature. For example, specifically, a transparent binder made of a synthetic resin and a pigment made of a bismuth compound and a sulfur compound. It is preferable to use a solution diluted with a solvent and dispersed.
The bismuth compound may be at least one compound selected from 3,2-bismuth oxide, basic bismuth nitrate, bismuth hydroxide, basic bismuth acetate, and basic bismuth carbonate.
Examples of the sulfur compound include at least one compound selected from inorganic sulfur compounds such as sulfur, zinc sulfide, antimony sulfide, and calcium sulfide, organic sulfur compounds such as thiocarboanilide, and amino acids containing sulfur such as cysteine, and the like. Derivatives can be used.
Examples of the transparent binder include thermoplastic resins, natural resins, waxes, rubbers, higher fatty acids, aliphatic alcohols, fatty acid esters including higher fatty acid esters, amides, lactones, lactams, aromatic alcohols, ethers. And the like are preferred because they have the advantage of excellent ink adhesion and heat resistance stability to a synthetic resin film (adhered body) without ink floating after sterilization by boiling or retort.
Specifically, examples of the dibasic acid used in the polyester polyol include adipic acid, phthalic anhydride, isophthalic acid, terephthalic acid, maleic acid, fumaric acid, succinic acid, oxalic acid, malonic acid, and azelaic acid. Etc., and corresponding acid anhydrides can also be used.
The heat treatment indicator ink layer 4 contains the pigment in a blending ratio (pigment / transparent binder) in the range of 1/4 to 2/1 with respect to the transparent binder made of the ink resin. Is preferably used, more preferably in the range of 1/2 to 1/1, and can be produced by kneading and dispersing with a three-roll mill.
If the blending ratio of the pigment / transparent binder is more than 2/1, it is not preferable because delamination occurs after precipitation or heating of the pigment. If the blending ratio is less than ¼, color development due to heating is poor, which is not preferable.

The heat treatment indicator ink layer 4 is a layer formed on the base material layer 1 and can be formed on the front surface or the back surface. Among them, by forming the ink layer on the back surface, the heat treatment indicator ink layer 4 is heated. This is preferable because discoloration can be prevented and peeling of the ink layer due to external impact can be prevented.
In the present invention, the indicator ink layer 4 for heat treatment is preferably formed by a printing method using an inkjet method, and it is not necessary to discard a large amount of residual ink as compared with conventional gravure printing. In addition, because there is no need to wash the ink pan, it is possible to prevent quality accidents without being mixed into the ink of the next item, and to improve productivity in the case of multi-product small lot production. Has the advantage.
Specifically, by forming the heat treatment indicator ink layer 4 to have a thickness of 0.1 μm or more and 3 μm or less, even if heat treatment such as boil sterilization or retort sterilization is performed, ink adhesion does not occur. It has the advantage of being excellent in properties.
On the other hand, if the heat treatment indicator ink layer 4 is formed with a film thickness exceeding 3 μm, the ink adhesion is inferior, ink floating tends to occur, characters and colors are blurred, and the amount of ink used increases. In terms of material cost, it is not preferable.
In addition, if the ink film thickness is less than 0.1 μm, the ink coating film is thin, so the concentration necessary for discoloration cannot be obtained, which is not preferable.

The medium layer and / or the white ink layer 5 according to the present invention is a polyurethane resin composition, a resin composition containing a polyamide resin and nitrocellulose, a urethane and vinyl chloride copolymer resin composition, or the like.
Specifically, for example, a medium whose viscosity is adjusted by adding white compound (manufactured by The Inktec Co., Ltd.) to Calton NEW HP Medium (manufactured by The Inktec Co., Ltd.) is used as the medium. it can.
Moreover, since it can prevent blocking, it is preferable to coat what added additives, such as polyethylene wax, in any of said medium layers.
The medium layer and / or the white ink layer 5 or the coating agent preferably has a viscosity of about 17 seconds to 18 seconds with Zahn Cup # 3 because a uniform coating surface can be obtained.
As the pigment of the white ink layer 5, for example, titanium oxide, calcium carbonate, magnesium carbonate, a mixture of two or more of these, and the like can be used.
Examples of binders (heat-meltable substances) used in such white ink include chlorinated polyolefins such as chlorinated polyethylene and chlorinated polypropylene, polyester resins, thermoplastic urethane resins, acrylic resins, vinyl acetate resins, and vinyl chloride-vinyl acetate. A copolymer, a thermoplastic resin such as a cellulose resin, a thermosetting resin such as a thermosetting urethane resin, an epoxy resin, or the like is used as a single substance or a mixture of these resins.
As a method for forming the medium layer and / or the white ink layer 5, a printing method such as gravure printing, offset printing, silk screen printing, flexographic printing, and the like can be used. The coating can be formed, and the thickness of the coating solution is preferably about 1 μm to 8 μm, more preferably about 2 μm to 5 μm.
When the medium layer and / or the white ink layer 5 is formed between the heat treatment indicator ink layer 4 and the adhesive layer 3 and subjected to treatment such as boil sterilization and retort sterilization, the ink of the heat treatment indicator ink layer is obtained. There is an advantage that the ink does not float, has excellent ink adhesion, and can maintain the adhesion over time.
Moreover, since the medium layer and / or the white ink layer 5 serves as a base by being used as a printing ink, when overprinting with the heat treatment indicator ink layer 4 or the like, the heat treatment indicator ink layer 4 This is preferable because the entire pattern can be clearly seen, the design is improved, and the contents are concealed.

In the present invention, the surface film layer 13 may be any film provided on the surface of the above-mentioned medium layer and / or the white ink layer 5 and made of a heat-resistant resin.
Specifically, for example, a polyester resin film, a polypropylene resin film, a polyamide resin film, a vinylidene chloride resin film, a polyacetal resin film, or the like can be used.
And as said resin film, any things, such as an unstretched film or the stretched film extended | stretched to the uniaxial direction or the biaxial direction, can be used.
The thickness of the film is about 5 to 100 μm, preferably about 10 to 50 μm.
Further, instead of providing the surface film layer 13, the surface may be coated with a resin.
Specifically, for example, an acrylate resin, a polyester resin, a cellulose resin, or the like can be used. The thickness of the coating solution is preferably about 2 μm to 5 μm.

Next, in the present invention, the heat seal layer 2 will be described. Such a layer may be any layer that can withstand retort processing and can be melted by heat and fused to each other.
Specifically, for example, low-density polyethylene film, medium-density polyethylene film, high-density polyethylene film, linear low-density polyethylene film, polypropylene film, ethylene-vinyl acetate copolymer resin film, ionomer-resin film, ethylene-acrylic Acid copolymer resin film, ethylene-ethyl acrylate copolymer resin film, ethylene-methacrylic acid copolymer film, ethylene-propylene copolymer film, methylpentene resin film, polybutene resin film, acid-modified polyolefin resin, etc. The resin film can be used.
The thickness of the film is 10 to 300 μm, preferably about 20 to 100 μm.

Next, in the present invention, as a material constituting the intermediate layer 6 forming the laminate, for example, a coating of polyvinylidene chloride resin having a barrier property against oxygen, water vapor, etc., polyvinyl alcohol, ethylene-vinyl acetate Polymer film saponified resin film or sheet, film deposited on inorganic material such as aluminum, alumina oxide, silicon oxide, etc., colorant such as pigment to resin, other desired additives and kneading Various colored resin films or sheets having light-shielding properties formed into a film can be used.
These materials can be used alone or in combination. The thickness of the above film or sheet is arbitrary, but is usually about 5 to 300 μm, and more preferably about 10 to 100 μm.

In the present invention, since packaging containers are usually subjected to severe physical and chemical conditions, severe packaging suitability is required as a material constituting the intermediate layer according to the present invention. , Materials that satisfy various conditions such as deformation prevention strength, drop impact strength, pinhole resistance, heat resistance, sealing performance, quality maintenance, workability, hygiene, etc. it can.
Specifically, for example, polypropylene, ethylene-propylene copolymer, ethylene-vinyl acetate copolymer, ionomer resin, ethylene-ethyl acrylate copolymer, ethylene-acrylic acid or methacrylic acid copolymer, methylpentene Polymer, polybutene resin, polyvinyl chloride resin, polyvinyl acetate resin, polyvinylidene chloride resin, vinyl chloride-vinylidene chloride copolymer, poly (meth) acrylic resin, polyacrylonitrile resin, polystyrene Resin, acrylonitrile-styrene copolymer (AS resin), acrylonitrile-butadiene-styrene copolymer (ABS resin), polyester resin, polyamide resin, polycarbonate resin, polyvinyl alcohol resin Saponified ethylene-vinyl acetate copolymer, Tsu Motokei resins, diene resins, polyacetal - Le resins, polyurethane resins, nitrocellulose - scan, film or sheet of a resin other like - Select from them on any can be used.
In addition, for example, a film such as cellophane, a synthetic paper, or the like can be used.
In the present invention, the above-described film or sheet may be any of unstretched, uniaxially or biaxially stretched.
Moreover, although the thickness is arbitrary, it can select and use from the range of several micrometers-about 300 micrometers.
Furthermore, in the present invention, the film or sheet may be a film having any property such as extrusion film formation, inflation film formation, and coating film.

Next, in the present invention described above, a method for producing a laminate using the above materials will be described. As such a method, a method for laminating a normal packaging material, for example, wet lamination is used. , Dry lamination method, solventless dry lamination method, extrusion lamination method, T-die extrusion molding method, co-extrusion lamination method, inflation method, co-extrusion inflation method, etc. be able to.
Thus, in the present invention, when performing the above-mentioned lamination, if necessary, pretreatment such as corona treatment, ozone treatment, frame treatment, etc. can be applied to the film.
Examples of the adhesive layer 3 according to the present invention include anchor coating agents such as polyester, isocyanate (urethane), polyethyleneimine, polybutadiene, and organic titanium, or polyurethane and polyacrylic. An anchor coating agent such as a laminating adhesive such as polyester, epoxy, polyvinyl acetate, cellulose, and the like, an adhesive, and the like can be used.

Next, in the present invention, a method for making bags or boxes using the laminate as described above will be described. For example, in the case where the packaging container is a flexible packaging bag made of a plastic film or the like, the above method is used. Using the laminate manufactured in the above, the face of the inner heat seal layer is made to face each other, and the two layers are folded, or two of them are overlapped, and the peripheral edge is heated to the heat seal. Thus, a bag can be formed by providing a seal portion.
Thus, as the bag making method, the above laminated body is folded with the inner layer surfaces facing each other, or the two sheets are overlapped, and the peripheral edge of the outer periphery is, for example, a side sheet. Seal type, two-sided seal type, three-sided seal type, four-sided seal type, envelope-sealed seal type, jointed seal type (pillar seal type), pleated seal type The various types of packaging containers according to the present invention can be manufactured by heat sealing in the form of a heat sealing such as a flat bottom sealing type, a square bottom sealing type, or the like.
In addition, for example, self-supporting packaging bags (standing pouches), spout pouches and the like can be manufactured. Further, in the present invention, a tube container, an in-mold label, a cup is used by using the above laminated material. A cover material for a product can also be manufactured.
In the above, as the heat seal method, for example, a bar seal, a rotary roll seal, a belt seal, an impulse seal, a high frequency seal, an ultrasonic seal and the like are known. It can be done by the method.
In the present invention, a spout such as a one-piece type, a two-piece type, or the like, or a zipper for opening and closing can be arbitrarily attached to the packaging container as described above.

In the present invention, the packaging container manufactured as described above can seal and sterilize a wide variety of foods and the like.
Examples of foods that are particularly suitable for filling and sealing in the above packaging containers include retort foods such as curry and stew, seasonings such as miso, kneaded products such as konjac, chikuwa and koji, and smoked products such as ham and sausage. Foods and beverages such as cooked foods such as meatballs and hamburgers, processed fishery products, pickles, boiled rice cakes, and luxury products.

  In the present invention, the packaging body filled and packaged in the packaging container produced as described above is placed in, for example, a retort kettle and subjected to retort treatment at a temperature of 120 ° C. and a pressure of 180 kPa for 30 minutes. By changing the color of the processing indicator ink layer, the presence or absence of processing such as boil sterilization or retort sterilization of the package can be detected accurately, quickly, and easily. In addition, the ink adhesion is excellent and can be maintained over time, and an excellent packaged product can be obtained.

Next, the present invention will be described in more detail according to specific examples.
(Embodiment 1) First, as a base material layer 1, a heat treatment indicator ink 4 (film thickness, 1 μm) is injected onto one side of a 12 μm-thick biaxially stretched polyethylene terephthalate (hereinafter referred to as “PET”) film. Using the printer name “KX-D” (manufactured by Hitachi Industrial Equipment Systems Co., Ltd.), the print head printed desired characters in a range of 5 mm length × 10 mm width.
In addition, the indicator ink 4 for heat treatment uses, as a binder, a one-component ink resin (7% by weight) using a polyurethane resin and a polyisocyanate oligomer crosslinking agent in combination, and a bismuth compound and a sulfide (3) as a pigment. And a solvent having a characteristic of changing from white to brown when heated at a temperature of about 90 ° C. for a heating time of about 20 minutes.
After that, continuously on the indicator ink layer formed as described above, white printing ink 5 containing medium as a binder is solid printed with a film thickness of 2 μm by a gravure printing method at a continuous 100,000 m (16 hours). Overprint printed.
Furthermore, 3.5 g / m ² (dried state) of polyurethane adhesive is applied as the adhesive layer 3 to the printing surface using the medium formed above as a binder, and 15 μm biaxially stretched nylon (hereinafter referred to as “ON”). .) A laminated film was prepared by laminating the film with a dry lamination method.
Next, 3.5 g / m ² (dry state) of polyurethane adhesive is applied to the ON film surface of the laminated film obtained above, and a 7 μm thick aluminum foil (hereinafter referred to as “Al”) is thick. An unstretched polypropylene (hereinafter referred to as “CPP”) film having a thickness of 70 μm is sequentially laminated by a dry lamination method, and the layer structure is PET film 12 μm / indicator ink layer / white printing layer / adhesive layer / ON film 15 μm / A laminate of Example 1 according to the present invention of adhesive layer / Al 7 μm / adhesive layer / CPP film 70 μm (inner surface) was prepared and aged at 40 ° C. for 3 days.

The types of materials used in Example 1 are shown below.
PET film: Trade name “T4102” (manufactured by Toyobo Co., Ltd.)
ON film: Product name “Bonyl W15” (manufactured by Kojin Co., Ltd.)
CPP film: Trade name “ZK93K” (manufactured by Toray Synthetic Film Co., Ltd.)
Printing ink: Trade name “NewLP Super R611 White” / Curing agent: Trade name “LP Super Hardener” (manufactured by Toyo Ink Manufacturing Co., Ltd.)
Adhesive: Trade name “DIC LX703”, manufactured by Mitsui Takeda Chemical Co., Ltd.

Next, using the laminate obtained above, two sheets having a size of 130 mm × 170 mm are cut out, CPP films are arranged so as to face each other, and two sides and one side are thermocompression bonded with a width of 10 mm (condition 200) And 2 kg / cm ² , 0.5 seconds) to obtain a retort pouch.
Next, 100 g of water was filled as the contents, and the upper end seal part was pressed and a semi-finished product was manufactured.
Next, retort sterilization was performed in a steam retort kettle under conditions of a temperature of 120 ° C. and a pressure of 180 kPa for 30 minutes to obtain a retort treatment package 6 according to the present invention.

The retort-processed packaging body 6 manufactured above can visually recognize the presence or absence of the retort sterilization treatment of the package body from the white color to the brown color after the retort process. Lamination did not occur, and a packaged product having excellent ink adhesion could be obtained.
In addition, the remaining amount of indicator ink for heat treatment in the ink jet print head is 50 g, which reduces the amount of waste ink used compared to the conventional gravure printing method and is superior in terms of cost and environment. It was.
In addition, by printing the indicator ink for heat treatment with the print head of the ink jet printer, the moisture outside the print head could be blocked, so it was possible to prevent moisture from entering the indicator ink. It was possible to suppress deterioration over time such as prevention of discoloration due to water mixing and ink adhesion.
Furthermore, since it is possible to smoothly switch to the next item without performing ink pan cleaning, productivity can be improved and the work load on the operator can be reduced.

(Comparative Example 1)
As the indicator ink for heat treatment, a two-component ink resin (15% by weight) using a polyurethane-based resin and a polyisocyanate oligomer crosslinking agent in combination is used as a binder, and a bismuth compound and sulfide (10% by weight) are used as pigments. ) And a solvent mixture of isopropyl alcohol, methyl ethyl ketone, and toluene (75% by weight) as a solvent, and has a characteristic of changing from white to brown when heated at a temperature of about 90 ° C. for a heating time of about 20 minutes. used.
Then, a heat treatment indicator ink (film thickness, 1 μm) is applied to one side of a 12 μm thick biaxially stretched polyethylene terephthalate (hereinafter referred to as “PET”) film by a gravure printing method in a range of 5 mm × 10 mm. Is printed.
After that, on the indicator ink layer formed as described above, a white printing ink containing medium as a binder was continuously printed at a thickness of 2 μm by a gravure printing method at a continuous 100,000 m (16 hours). Printed and printed.
Furthermore, 3.5 g / m ² (dry state) of a polyurethane adhesive is applied to the printing surface using the medium formed as a binder, and a 15 μm biaxially stretched nylon (hereinafter referred to as “ON”) film is applied. A laminated film was prepared by laminating by a dry lamination method.
Next, 3.5 g / m ² (dry state) of polyurethane adhesive is applied to the ON film surface of the laminated film obtained above, and a 7 μm thick aluminum foil (hereinafter referred to as “Al”) is thick. A 70 μm thick unstretched polypropylene (hereinafter referred to as “CPP”) film is sequentially laminated by a dry lamination method, and the layer structure is PET film 12 μm / indicator ink layer / white printing layer / adhesive layer / ON film 15 μm / adhesion. A laminate of Comparative Example 1 having an agent layer / Al 7 μm / adhesive layer / CPP film 70 μm (inner surface) was prepared and aged at 40 ° C. for 3 days.

The types of materials used in Comparative Example 1 are shown below.
PET film: Trade name “T4102” (manufactured by Toyobo Co., Ltd.)
ON film: Product name “Bonyl W15” (manufactured by Kojin Co., Ltd.)
CPP film: Trade name “ZK93K” (manufactured by Toray Synthetic Film Co., Ltd.)
Indicator ink for heat treatment: Trade name “RG ink”: NOF Giken Kogyo Co., Ltd. / Curing agent: Trade name “LP Super Hardener” (manufactured by Toyo Ink Manufacturing Co., Ltd.)
Mixed solvent: Trade name “SL-302” (manufactured by Toyo Ink Manufacturing Co., Ltd.)
Printing ink: Trade name “NewLP Super R611 White” / Curing agent: Trade name “LP Super Hardener” (manufactured by Toyo Ink Manufacturing Co., Ltd.)
Adhesive: Trade name “DIC LX703”: manufactured by Mitsui Takeda Chemical Co., Ltd.

Next, using the laminate obtained above, two sheets having a size of 130 mm × 170 mm are cut out, CPP films are arranged so as to face each other, and two sides and one side are thermocompression bonded with a width of 10 mm (condition 200) And 2 kg / cm ² , 0.5 seconds) to obtain a retort pouch.
Next, 100 g of water was filled as the contents, and the upper end seal part was pressed and a semi-finished product was manufactured.
Next, retort sterilization was carried out in a steam retort kettle at a temperature of 120 ° C. and a pressure of 180 kPa for 30 minutes to obtain a retort-treated packaging according to the present invention.

After the retort treatment, the retort-treated packaging body produced above can visually recognize the presence or absence of the retort sterilization treatment of the package body from the white color to the brown color by changing the indicator ink printing part for heat treatment in the packaging container. In other words, it was possible to obtain a packaged product excellent in ink adhesion.
However, after printing, the remaining amount of indicator ink for heat treatment remaining in the ink pan in the gravure printing machine was 8 kg, and the cost was increased due to disposal of the remaining ink used.
Further, since the ink pan is an open system by printing the heat treatment indicator ink by the gravure printing method, moisture in the air is likely to be mixed into the ink, and the hue of the heat treatment indicator ink is the printing time, 6 When the time exceeded, the hue of the ink changed (color difference between the hue of the ink immediately after the start of printing and the hue of the ink after 6 hours, ΔE = 1.89).
Furthermore, when switching to the next item, it was necessary to carefully perform ink pan cleaning in order to prevent mixing of used indicator ink.

(Measurement of moisture content)
The moisture content of the indicator ink for heat treatment remaining in the ink pan before printing and after printing for 6 hours was measured with a Karl Fischer moisture meter “MKA-610”, manufactured by Kyoto Electronics Industry Co., Ltd.
The ink moisture content in the print head of the ink jet printer was 0.09% moisture content before printing, and 0.09% moisture content after printing.
On the other hand, the water content of the ink in the ink pan of the gravure printing machine was the water content before printing, 0.09%, and the water content after printing, 0.8%.

As is clear from the above explanation, the water content of the ink in the ink pan of the gravure printing machine increased while the water content of the indicator ink for heat treatment in the print head of the ink jet printer did not change. It was.
As a result, the laminate with a heat treatment indicator according to the present invention has a high productivity and long time without deterioration of the ink by forming the heat treatment indicator ink composition with the print head of the injection printer. The time can be printed.
Furthermore, after filling the contents, after processing such as boil sterilization, retort sterilization, the above heat treatment indicator ink layer does not cause ink floating, excellent in ink adhesion, heat resistance, water resistance, over time A layered product with a heat treatment indicator that can retain ink and can visually recognize the presence or absence of processing such as boil sterilization and retort sterilization of the package by color change, and a package using the same It is.

It is sectional drawing which shows the layer structural example of the laminated body with a heat processing indicator of this invention. It is sectional drawing which shows the layer structural example of the laminated body with a heat processing indicator of another aspect of this invention. It is sectional drawing which shows the layer structural example of the laminated body with a heat processing indicator of another aspect of this invention. It is sectional drawing which shows the layer structural example of the laminated body with a heat processing indicator of another aspect of this invention. It is a perspective view which shows an example of the packaging container using the laminated body with a heat processing indicator of this invention. It is a perspective view which shows an example of the package body which filled and packed the contents using the packaging container shown in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Base material layer 2 Heat seal layer 3 Adhesive layer 4 Heat treatment indicator ink layer 5 Medium layer and / or white ink layer 6 Intermediate layer 7 Opening part 8 Side seal part 9 Bottom seal part 10 Laminated body 11 with a heat treatment indicator 11 Top seal part 12 Contents 13 Surface film layer 14 Gravure printing area of heat treatment indicator ink 20 Packaging container with heat treatment indicator 30 Package with heat treatment indicator

Claims (3)

An indicator ink composition for heat treatment that contains a pigment and a binder made of a synthetic resin and changes color irreversibly by heating in a laminate in which a base film layer and a heat seal layer are sequentially laminated via an adhesive layer An indicator ink layer is formed on the laminate surface side of the base film layer , and the thickness of the indicator ink layer is 0.1 μm or more and 3 μm or less by an ink jet printing method. And the pigment is composed of a bismuth compound and a sulfur compound, and the blending ratio of the pigment to the binder (pigment / binder) is in the range of 1/4 to 2/1. A laminate with an indicator for heat treatment. 2. The laminate with an indicator for heat treatment according to claim 1 , wherein a medium layer and / or a white ink layer is formed on the heat treatment indicator ink composition by overprinting. It forms using the laminated body with the indicator for heat processing in any one of Claims 1-2 , The package body characterized by the above-mentioned.

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