JP6698432B2 - Temperature-time integrated history display composition and temperature-time integrated indicator using the same - Google Patents

Description

  The present invention relates to a temperature-time integration history display composition and a temperature-time integration indicator using the same.

  Conventionally, it has been studied to use a substance having a color change as an aging indicator composition. For example, there is a known time-lapse indicator composition comprising a mixture of a developer such as a vinylidene chloride polymer compound, an electron-donating color-developing organic compound, and a desensitizer (Patent Document 1). ).

JP, 06-122863, A

  The invention described in Patent Document 1 relates to an elapsed-time indicator composition using a color tone change of a colored or color forming organic compound, etc., and a reaction giving the color tone change is not affected by environmental conditions such as temperature. To be a part of the task.

  By the way, in the storage of fresh foods, etc., the temperature is not always maintained constant, and the desired temperature is not maintained due to the frequency of opening/closing of the refrigeration or freezing storage device, power failure, human error in temperature setting, etc. There may be cases where it is not maintained. Therefore, there is a demand for easily recognizing the integration history taking into consideration not only time but also temperature. However, in the conventional elapsed-time indicator composition as described in Patent Document 1, although the passage of time can be visually recognized, it is extremely difficult to visually recognize the cumulative history of both temperature and time. there were.

  The present invention has been made in view of the above problems, and an object thereof is to provide a temperature-time integrated history display composition that provides an indicator capable of visually recognizing integrated history of temperature and time, and the use thereof. A temperature-time integration indicator that has been used.

  The present inventors have found that the above problems can be solved by combining a polyvinylidene chloride resin and a basic compound, and have completed the present invention.

  A first aspect of the present invention is a temperature-time integrated history display composition containing a polyvinylidene chloride resin and a basic compound. The basic compound is preferably at least one selected from the group consisting of alkali metal hydroxides and amines. The amine is preferably piperidine.

  A second aspect of the present invention is a temperature-time integration indicator comprising the composition. The indicator preferably includes a laminate including a resin layer containing the polyvinylidene chloride resin and a layer containing the basic compound. In the indicator, it is also preferable that the region containing the polyvinylidene chloride resin and the region containing the basic compound are separated via a peelable joint.

  ADVANTAGE OF THE INVENTION According to this invention, the temperature-time integrated history display composition which gives the indicator which can visually recognize the integrated history of temperature and time, and the temperature-time integrated indicator using this can be provided.

It is a graph which shows the result of having measured the change of Hunter whiteness with progress of the preservation days in Example 1 and Comparative Examples 2-5. FIG. 10 is a plan view schematically showing a temperature-time integration indicator used in Example 10.

<Temperature-time accumulated history display composition>
The temperature-time integration history display composition according to the present invention contains a polyvinylidene chloride resin and a basic compound. By using a combination of a polyvinylidene chloride resin and a basic compound, the above composition can provide an indicator by which the cumulative history of temperature and time can be visually recognized.

[Polyvinylidene chloride resin]
In the temperature-time accumulated history display composition according to the present invention, the polyvinylidene chloride resin (hereinafter, also referred to as “PVDC”) may be a vinylidene chloride homopolymer, but usually, vinylidene chloride is 60 to 98 mass %. And 2 to 40 mass% of another monomer copolymerizable with vinylidene chloride. Other monomers copolymerizable with vinylidene chloride include, for example, vinyl chloride; alkyl acrylates such as methyl acrylate, ethyl acrylate, butyl acrylate, and lauryl acrylate (alkyl groups having 1 to 18 carbon atoms). ); Methacrylic acid alkyl esters such as methyl methacrylate, butyl methacrylate, and lauryl methacrylate (alkyl groups having 1 to 18 carbon atoms); vinyl cyanide such as acrylonitrile; aromatic vinyl such as styrene; carbon numbers such as vinyl acetate Vinyl ester of aliphatic carboxylic acid having 1 to 18; alkyl vinyl ether having 1 to 18 carbon atoms; vinyl polymerizable unsaturated carboxylic acid such as acrylic acid, methacrylic acid, maleic acid, fumaric acid; maleic acid, fumaric acid, itaconic acid And the like, alkyl esters of vinyl-polymerizable unsaturated carboxylic acids (including partial esters, the alkyl group having 1 to 18 carbon atoms), and the like. More preferably, it is at least one selected from the group consisting of vinyl chloride, methyl acrylate or lauryl acrylate. As the other monomer copolymerizable with vinylidene chloride, one type may be used alone, or two or more types may be used in combination. The copolymerization ratio of the other monomer is more preferably 3 to 35% by mass, still more preferably 3 to 25% by mass, and particularly preferably 4 to 22% by mass. When the copolymerization ratio of the other monomer is 2 to 40% by mass, melt processability, stability and the like can be easily maintained well. PVDC may be used alone, or may be used as a mixture of two or more kinds in order to improve melt processability. PVDC can be synthesized by an arbitrary polymerization method such as a suspension polymerization method, an emulsion polymerization method or a solution polymerization method.

[Basic compound]
In the temperature-time integrated history display composition according to the present invention, the basic compound accelerates the dehydrochlorination reaction of the polyvinylidene chloride resin, thereby causing color development. Color development proceeds with time, and the higher the temperature, the easier it is to proceed. Therefore, the cumulative history of temperature and time can be visually recognized by measuring the change in color tone of the composition. The basic compounds can be used alone or in combination of two or more.

The basic compound is not particularly limited, and examples thereof include alkali metal hydroxides and amines. The alkali metal hydroxide is not particularly limited, and examples thereof include sodium hydroxide and potassium hydroxide, and sodium hydroxide is preferable from the viewpoints of handleability, availability, cost and the like. The amine is not particularly limited, and examples thereof include alicyclic amine, acyclic aliphatic amine, aromatic amine, and the like, and alicyclic amine is preferable from the viewpoint of safety and the like. The number of carbon atoms in the amine is not particularly limited and is, for example, 1 to 10, preferably 2 to 8, and more preferably 3 to 6. The total number of amino groups (that is, —NH ₂ ) and substituted amino groups (groups obtained by substituting hydrogen atoms of amino groups with organic groups) in the amine is not particularly limited, and is, for example, 1 to 3. And preferably 1 or 2 and more preferably 1. The amine may have a substituent. The substituent is not particularly limited, and examples thereof include a halogen atom such as a fluorine atom, a chlorine atom, a bromine atom and an iodine atom; a hydroxyl group; and a nitro group. The amine may have a hetero atom in the carbon chain. The alicyclic amine is not particularly limited, and examples thereof include piperidine and morpholine. From the viewpoint of reactivity and the like, piperidine is preferable. The acyclic aliphatic amine is not particularly limited, and examples thereof include trimethylamine and triethylamine, and trimethylamine is preferable from the viewpoint of reactivity and the like. The aromatic amine is not particularly limited, and examples thereof include aniline. Particularly, as the amine, piperidine is preferable from the viewpoint of reactivity and the like.

  In the temperature-time integration history display composition according to the present invention, the amount of the basic compound is not particularly limited, but is, for example, 0.01 to 20 parts by mass with respect to 100 parts by mass of the polyvinylidene chloride resin, and the reaction From the viewpoint of properties, etc., it is preferably 0.03 to 15 parts by mass, more preferably 0.05 to 15 parts by mass.

[Other ingredients]
The temperature-time integration history display composition according to the present invention may contain other components as long as the effects of the present invention are not impaired. Examples of the other components include a solvent; known additives such as heat stabilizers; and other resins.

(solvent)
The solvent is added to the temperature-time integration history display composition according to the present invention, if necessary, for example, to dissolve the basic compound and/or to disperse the polyvinylidene chloride resin. The solvent is not particularly limited, and examples thereof include organic solvents and water. The organic solvent is not particularly limited, and examples thereof include alcohol such as ethanol. From the viewpoint of solubility of the basic compound, when the alkali metal hydroxide is used as the basic compound, the solvent is preferably water, and when the amine is used as the basic compound, the solvent is preferably ethanol.

(Additive)
The additive, when using a polyvinylidene chloride resin, for example, in the form of a film containing a polyvinylidene chloride resin, in the form of a fragment of the film, in the form of a pulverized product of the film, if necessary, the film Is added to. Examples of the additive include a heat stabilizer, a plasticizer, a processing aid, a colorant, an ultraviolet absorber, a pH adjuster, and a dispersion aid, which are added for the purpose of improving various properties and molding processability of the film. Various additives such as

(Other resins)
Other resins are various properties of the film when the polyvinylidene chloride resin is used, for example, in the form of a film containing the polyvinylidene chloride resin, in the form of fragments of the film, or in the form of a pulverized product of the film. If necessary, it is added to the film for the purpose of improving molding processability. Examples of other resins include polyethylene wax, oxidized polyethylene wax, polyethylene (low-density polyethylene or high-density polyethylene), ethylene-vinyl acetate copolymer, acrylic acid ester homopolymer or copolymer, and methacrylic acid ester. Homopolymers or copolymers, methyl methacrylate-butadiene-styrene copolymers and the like can be mentioned.

[Form of Composition and Manufacturing Method]
The form of the temperature-time integration history display composition according to the present invention is not particularly limited as long as the polyvinylidene chloride resin and the basic compound are combined, and for example, the polyvinylidene chloride resin and the basic compound are combined. A laminate containing a resin layer containing a polyvinylidene chloride resin and a layer containing a basic compound; a region containing the polyvinylidene chloride resin and a region containing the basic compound are separated via a peelable joint. And the like, which are isolated from each other.

  Examples of the form of the polyvinylidene chloride-based resin in the above mixture include a pulverized product of a film containing the polyvinylidene chloride-based resin. In the above structure, examples of the form of the basic compound include a solution of the basic compound. The above mixture can be obtained by mixing a polyvinylidene chloride resin and a basic compound by a known method.

  Examples of the laminate include a laminate in which a resin layer containing a polyvinylidene chloride resin and a layer containing a basic compound are laminated adjacent to each other, a resin layer containing a polyvinylidene chloride resin and a basic compound. A laminated body in which the containing layer is laminated via an intervening layer is mentioned. Examples of the resin layer in the laminate include a film containing a polyvinylidene chloride resin. The thickness of the polyvinylidene chloride resin film is not particularly limited and is, for example, 5 to 15 μm. Examples of the layer containing the basic compound in the laminate include filter paper impregnated with the solution of the basic compound. Examples of the intervening layer include a film containing a resin other than a polyvinylidene chloride resin, and specifically, a film containing a linear low-density polyethylene, a film containing an ethylene vinyl acetate copolymer, and an ethylene acrylic resin. Examples thereof include a film containing a methyl acid copolymer and a film containing Ionomer. The intervening layer may be composed of one layer or two or more layers. The laminate is, for example, by laminating a film containing a polyvinylidene chloride resin and a filter paper impregnated with a solution of the basic compound, or a laminate containing a film containing a polyvinylidene chloride resin and the intervening layer. It can be obtained by stacking a body and a filter paper impregnated with the solution of the basic compound such that the intervening layer and the filter paper are in contact with each other.

  In the above structure, the forms of the polyvinylidene chloride resin and the basic compound are the same as those described for the above mixture. The structure is separated by, for example, dividing the inside of a bag body made of a transparent barrier film into two regions, adding a polyvinylidene chloride resin in one region, and weakly sealing the boundary between the two regions. It can be obtained by forming a possible joint and then inserting a basic compound in the other region and tightly sealing and sealing the bag body.

  In any of the embodiments, as a raw material of the polyvinylidene chloride resin, mill ends produced in the process of producing a film containing the polyvinylidene chloride resin can be used. Such mill ends are usually discarded, but in the present invention, resource saving is realized through effective utilization of the mill ends as a raw material, and at the same time, the temperature-time integration history display composition is achieved at low cost. An object and a temperature-time integration indicator using the same can be manufactured.

<Temperature-time integration indicator>
The temperature-time integration indicator according to the present invention comprises the temperature-time integration history display composition composition according to the present invention. By providing the above composition in the above indicator, it becomes possible to visually recognize the cumulative history of temperature and time.

  In one embodiment (hereinafter, also referred to as “embodiment 1”) of the indicator, the indicator includes a laminate including a resin layer containing the polyvinylidene chloride resin and a layer containing the basic compound. In the indicator according to Embodiment 1, the polyvinylidene chloride-based resin and the basic compound form the laminate described in the section “Form of composition”, and the indicator is used to produce the laminate, for example. However, it can be obtained by optionally hermetically packaging the laminate with a transparent barrier film.

  In another embodiment of the indicator (hereinafter, also referred to as “embodiment 2”), the region containing the polyvinylidene chloride resin and the region containing the basic compound are separated via a peelable joint. It is isolated. In the indicator according to the second embodiment, the polyvinylidene chloride resin and the basic compound form the structure described in the section “Form of composition”, and the indicator is similar to the structure, for example. Can be manufactured. In the indicator according to the second embodiment, since the polyvinylidene chloride resin and the basic compound are isolated from each other, each component can be stably stored until the detection of the temperature and time accumulated history is started. it can. Since it is the peelable joint that separates the polyvinylidene chloride resin and the basic compound, the joint can be easily peeled by applying a force from the outside of the structure. As a result, the polyvinylidene chloride resin and the basic compound are mixed, and the color tone change can be started at a desired time.

  The temperature-time integration indicator according to the present invention is, for example, when storing an object such as fresh food, by storing it together with the object, the accumulated history of temperature and time received by the object is visually detected. It can be used for recognition. The temperature range that can be detected by the indicator is not particularly limited, and examples thereof include −40 to 60° C., and preferably −30 to 50° C.

  Hereinafter, the present invention will be described in more detail with reference to Examples, but the scope of the present invention is not limited to these Examples.

[Example 1 , Comparative Examples 2 to 5, Examples 6 and 7, and Comparative Examples 8 and 9]
A 2.5 cm square filter paper was impregnated with 0.5 ml of the basic compound solution shown in Table 1, and a 2 cm square PVDC film (NEW Kurerap manufactured by Kureha Co., Ltd., thickness: 10 μm) was placed on the 2.5 cm square filter paper, and 3.5 cm× Transparent barrier film made into a bag of 3.5 cm (13 μm GL, 15 μm Ny, and 80 μm CPP are laminated in this order via an adhesive layer, GL: transparent vapor deposition film manufactured by Toppan Printing Co., Ltd. , Ny: nylon, CPP: unstretched polypropylene), and hermetically sealed. The resulting package was exposed to the temperatures shown in Table 1 to examine the change in color tone. For the color tone change, a Nippon Denshoku Industries color difference meter SE6000 type is used, and the Hunter whiteness (W=100-((100-L*2)+a*2+b*2)1/2) is measured over time. Quantified by that. More specifically, Hunter whiteness was plotted against the number of storage days, and the absolute value of the slope of the obtained graph was used as the reaction rate, which was used as an index of color tone change. The results are shown in Table 1. In addition, about Example 1 and Comparative Examples 2-5, the said graph was each shown in FIG.1(a)-(e).

[Example 10]
A temperature-time integration indicator schematically shown in FIG. 2 was produced. That is, first, a bag of a transparent barrier film was produced by strongly sealing the edges of two transparent barrier films (relative sealing strength: 10). On the inner side of the bag, 0.1 g of a pulverized product of PVDC film (Kureha Co., Ltd., thickness: 10 μm) was put, and the center of the bag was weakly sealed (relative sealing strength: 5). 100 μl of a 10 mass% piperidine solution (solvent: ethanol) was put on the front side inside the bag, and the bag mouth was tightly sealed and sealed to produce a temperature-time integration indicator. The area where the piperidine solution was sealed was strongly pressed, and the weak seal in the center was broken to bring the pulverized product into contact with the piperidine solution to start the reaction. After the start of the reaction, the indicator was stored in a freezer at -20°C, and the color tone change was measured in the same manner as above. As a result, the reaction rate was 4.6. As a result of measuring the change in color tone in the same manner as above, except that the temperature was changed from -20°C to -40°C and -60°C, the reaction rates were 0.57 and 0.1, respectively.

[Example 11]
A 2.5 cm square filter paper was impregnated with 0.5 ml of a 1 mass% piperidine solution (solvent: ethanol), and a multilayer barrier film (VLDPE (3 μm)/EVA (22 μm) made into a bag of 3.5 cm×3.5 cm was produced. )/EMA (1.5 μm)/PVDC (7 μm)/EMA (1.5 μm)/EVA (10 μm)/Ionomer (10 μm), which is manufactured so that the surface on the Ionomer side is in contact with the filter paper. VLDPE: linear low-density polyethylene, EVA: ethylene-vinyl acetate copolymer, EMA: ethylene-methyl acrylate copolymer, /: adhesive layer) and sealed. The obtained package was stored at 37° C., and the change in color tone was examined in the same manner as above. As a result, the reaction rate was 4.8.

  It is presumed that the filter paper contacted the Ionomer in the multilayer barrier film, and the piperidine solution penetrated the Ionomer layer, EVA layer, and EMA layer to reach the PVDC layer.

Claims (6)

A temperature-time integrated history display composition containing a polyvinylidene chloride resin and piperidine , which is used at -40 to 60°C . Comprising the composition of claim 1, the temperature used Ru at -40~60 ℃ - time integrating indicator. Temperature comprises a laminate comprising a layer comprising a resin layer and piperidine containing Po Li vinylidene chloride resin - time integrating indicator. The indicator according to claim 3 , wherein in the laminate, a resin layer containing the polyvinylidene chloride resin and a layer containing the piperidine are laminated adjacent to each other. The indicator according to claim 3 , wherein in the laminate, the resin layer containing the polyvinylidene chloride resin and the layer containing piperidine are laminated with an intervening layer interposed therebetween. A region including the region and piperidine containing Po Li vinylidene chloride-based resin, are separated via the peelable junction temperature - time integrating indicator.

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