JP3282298B2 - Time indicator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a time indicator. More specifically, fungicides, fungicides, herbicides,
Visually determine the shelf life of products with limited shelf life such as plant growth regulators, pheromone preparations, juvenile hormone mimetics, insect repellents, repellents, deodorants, fragrances, pharmaceuticals, foods, etc. by color change Regarding the time indicator that was made possible.

[0002]

2. Description of the Related Art A composition comprising, as a time indicator, a color-forming organic compound component, a second component for coloring the same, and a third component for decolorizing the two-component coloring system when added to the system. Mainly spread and held on a substrate such as paper or nonwoven fabric, the second or third component of these three components, one component remaining after volatilization in the use environment and a color-forming organic compound component (See, for example, JP-A-62-235562, JP-A-63-60901, and JP-A-2-290591).
Has been conventionally known.

However, in these methods, the volatilization speed of the above-mentioned second or third component varies greatly depending on the use environment, and when clothes or the like come into contact with the volatilization surface, the volatilization speed is reduced to the clothes or the like rather than the volatilization speed. There is a problem in that the color change period is greatly affected by the use environment and is not constant, for example, because the color changes due to the high speed. In addition, when clothes or the like come into contact with the volatile surface, the color easily discolors to cause discoloration or spots on the clothes or the like, or when spread and held on a base material such as paper or nonwoven fabric, the discoloration period is generally longer. There are drawbacks such as being short and difficult to control the discoloration period. Furthermore, when used as a time indicator when attached to various products that have a validity period, it is applied to uses such as pharmaceuticals and foods from the viewpoint of environmental pollution due to the volatilization of the above second or third component into the use environment. There is also a problem in that the use scene is limited because it is difficult to use as a time indicator because the second or third component is difficult to volatilize in a small space or a closed space.

[0004]

The inventors of the present invention have conducted various studies to solve the above-mentioned problems, and as a result, distributed components causing color development or decoloration between the two superimposed layers to form a layer. Find the time indicator of the present invention that changes color,
This solves problems such as the environmental pollution due to the volatilization of the added components to the use environment, the discoloration of the indicator, and the difficulty in controlling the discoloration period because the discoloration period is easily affected by the use environment. The present invention was found to be usable by being attached to a product for a wide range of uses having the following.

[0005]

That is, the present invention relates to a method of forming a partition coefficient between a layer A and a layer B made of a thermoplastic resin or a pressure-sensitive adhesive when the layers A and B are overlapped. The concentration of the electron-donating color-forming organic compound in the layer) / (the concentration of the electron-donating color-forming organic compound in the layer A at the time of distribution equilibrium)] is 0.1 or more. By superimposing the layer A containing the decolored state and the layer B having the electron accepting property and being in the decolored state,
It is an object of the present invention to provide a time indicator characterized in that the color development of the layer B becomes darker with time, and that it is possible to indicate the lapse of time since both layers were superposed.

The time indicator of the present invention is one in which the electron-donating color-forming organic compound is distributed from the layer A to the layer B and changes color in the process of reaching a distribution equilibrium. As the distribution coefficient between the layer A and the layer B of the electron-donating color-forming organic compound at the use temperature increases, the thickness of the layer B with respect to the layer A increases, and the electron-donating property of the layer B during distribution equilibrium increases. Since the concentration of the chromatic organic compound increases, the change in color tone increases. The partition coefficient between the layer A and the layer B of the electron-donating color-forming organic compound is preferably 0.1 or more. When the distribution coefficient is 0.1, the thickness of the layer B is 10 times or more the thickness of the layer A, and when the distribution coefficient is 1, it is 1 time or more.
In this case, it is preferable that the value be 0.1 times or more. here,
At the operating temperature, the partition coefficient between the layer A and the layer B of the electron- donating color-forming organic compound is as follows:
The layers are overlapped, and the concentrations of the electron- donating color- forming organic compounds in the layer A and the layer B are measured with time, and the electron- donating color in the layers A and B when the distribution equilibrium is reached. By knowing the concentration of the organic compound, it can be calculated by the following equation. (Partition coefficient of electron-donating color-forming organic compound) = (concentration of electron-donating color-forming organic compound in layer B at distribution equilibrium) / (electron-donating colorability in layer A at distribution equilibrium) Concentration of organic compounds)

In order to suppress the emission of the electron-donating color-forming organic compound to the environment due to evaporation, migration, run-off, etc. in the time indicator of the present invention, the A-layer and the B-layer are superposed. A layer on which the electron-donating color-forming organic compound cannot pass is laminated on one side of each of the A-layer and the B-layer serving as the outer surface of May be covered and sealed with a barrier layer that cannot transmit. The barrier layer used depends on the type of the electron-donating color-forming organic compound, but a transparent material such as various films such as polyester, eval, nylon, polyvinylidene chloride, and polypropylene, and glass can be used as appropriate. Also, an opaque material such as aluminum or an inorganic vapor-deposited film may be used for a part of the barrier layer. These barrier layers and / or A
The layer and / or the layer B may be printed and colored in advance. For example, a color change such as printing a character such as "end of use" in the same color as the color of the electron-donating color-forming organic compound or coloring it in a color different from the color of the electron-donating color-forming organic compound. Can be made clearer.
Further, for example, an additive is added to the barrier layer within a range that does not impair the purpose of the present invention, for example, because an weathering agent for improving the weather resistance of the electron-donating color-forming organic compound is added. May be.

In the present invention, the electron-donating color-forming organic compound is not particularly limited as long as it is a compound whose color development in an electron-accepting atmosphere occurs reversibly at a use temperature. For example, compounds such as rhodamine lactams, fluorans, triphenylmethane phthalides, phenothiazines, indolyl phthalides, spiropyrans, leuco auramines and the like can be used. More specifically, for example, rhodamine B base, N-phenyl rhodamine lactam, crystal violet lactone, malachite green lactone, 1,3-dimethyl-6-diethylaminofluoran, 2- (2-chloroanilino) -6-dibutylamino Fluorane, 3,7-bis (dimethylamino) -10-benzoylphenothiazine, N-3,3-trimethylindolinobenzospiropyran, ethylleucomethylene blue and the like. These electron donating color-forming organic compounds may be used alone or in combination of two or more.

Many of the electron-donating color-forming organic compounds used in the present invention are in a crystalline state when they exist alone at ordinary operating temperatures and pressures. Since these compounds have low color developability in the form of crystals, they are melted by heating or dissolved by a solvent when they are blended in the layer A, whereby these compounds are dispersed in the layer A in a molecular state (a state not crystallized). Is preferred. When it is contained in the layer A in a crystalline state, it is preferable because the coloring property is low and the coloring is non-uniform, and it is necessary to incorporate a large amount of an electron-donating color-forming organic compound in order to form a uniform color. Absent.

The material of the layer A and the layer B in the present invention can be selected from various thermoplastic resins, adhesives and the like. Things as the A layer is not allowed to develop an electron-donating coloring organic compound, as the B layer is intended to develop the electron-donating coloring organic compound having an electron accepting property, electron donative coloration in use Temperature Partition coefficient of the organic compound
You can select a combination of 0.1 or more. Whether or not to develop the color of the electron-donating color-forming organic compound used by various thermoplastic resins and pressure-sensitive adhesives depends on the color-forming state when the electron-donating color-forming organic compound used in the A and B layers is blended. Can be determined by observing. Although it is not clear why the thermoplastic resin or the adhesive has an electron-accepting property and causes the electron-donating color-forming organic compound to develop color, it is not clear whether the carboxylic acid group or the acrylic acid group of the thermoplastic resin or the adhesive exists. Donating group,
Impurities such as catalyst residue, residual monomer and residual oligomer,
It is thought to be due to the presence and concentration of the crosslinking agent, additives and the like.

As the thermoplastic resin, electron donating color
Thermal processing can be performed below the thermal decomposition temperature of the organic compound , for example, branched low-density polyethylene, ethylene and α having 4 to 12 carbon atoms.
-Linear low-density polyethylene, high-density polyethylene, which is a copolymer with olefin, a copolymer of (ethylene and / or butene-1) with propylene, and a copolymer of (vinyl acetate and / or acrylate) with ethylene Examples thereof include copolymers and olefinic thermoplastic resins such as polypropylene, and these can be used alone or in combination of two or more. As the adhesive, conventionally known latex-based, natural rubber-based, SBR-based, polybutadiene-based, butyl rubber-based, synthetic rubber-based rubber-based adhesives, acrylic ester-based acrylic-based adhesives, silicon-containing Adhesives, silicone adhesives, urethane adhesives and the like can be used. As the type of the pressure-sensitive adhesive, any of an aqueous emulsion type, a solvent type, a non-solvent type, a cross-linked type, a non-cross-linked type and the like may be used. Generally, the higher the degree of crosslinking, the longer the discoloration period. The size of the A layer and the B layer can be appropriately different depending on the intended use. The size and shape of the A layer and the B layer may be the same, but those having different sizes and shapes may be used to clarify a change in color tone. In this case, calling the portion superposed A layer and B layer
The layer A, which is colored and does not overlap, remains decolored .

The compounding amount of the electron-donating color-forming organic compound is as follows:
Although it can be arbitrarily changed in consideration of a desired color tone and an effective period, it is usually 0.001 to 5 parts by weight of the electron-donating color-forming organic compound per 100 parts by weight of the A layer. If the amount of the electron-donating color-forming organic compound is less than 0.001 part by weight, the discoloration is unclear, and if the amount exceeds 5 parts by weight, the crystals of the electron-donating color-forming organic compound are formed inside the A layer. Or, it is not preferable because it is deposited on the surface.

The use of the present invention is not particularly limited, and it can be used by being attached to various products having an effective period. For example, the useful life of products such as fungicides / fungicides, herbicides, plant growth regulators, pheromone preparations, juvenile hormone mimics, insecticides, repellents, deodorants, fragrances, pharmaceuticals, animal and plant essential oils, and foods You can know by the discoloration of the time indicator.

The discoloration period of the time indicator of the present invention varies depending on the use temperature, but the distribution of the electron-donating color-forming organic compound in the layer A and the layer B and the distribution of the electron-donating color-forming organic compound are different. It can be controlled by factors such as the coefficient and the thickness of the A layer and the B layer, and can be arbitrarily set in a period of several hours to several years. The discoloration period of the time indicator becomes longer as the diffusivity in the A layer and the B layer is lower, the distribution coefficient is smaller, the thickness of the A layer is larger, and the thickness of the B layer is smaller. Further, in order to control the discoloration period, the A layer and / or the B layer may be a multilayer body having a layer made of a thermoplastic resin or an adhesive capable of transmitting an electron-donating color-forming organic compound on one or both sides thereof. Good.

[0015]

According to the present invention, the discoloration period is not affected by the use environment, the color is hardly discolored, the discoloration period can be easily controlled, and the environmental pollution due to the volatilization of the added component into the use environment is achieved. Thus, it is possible to provide a very useful time indicator that can be used in conjunction with a product having an effective period in a wide range of applications without using it.

[0016]

Next, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples. Example 1 A two-layer, three-layer film molded by the following method as layer A was
It was used after being cut into a cm square. Ethylene-methyl methacrylate copolymer (Aclift WH202 manufactured by Sumitomo Chemical Co., Ltd.)
After 100 parts by weight and 0.04 parts by weight of Rhodamine B base (manufactured by Taoka Chemical Industry Co., Ltd.) are melt-kneaded in a closed pressure kneader using shearing heat, they are supplied to an extruder and hot-cut while being extruded. Performed pelletization. Subsequently, a multilayer inflation apparatus equipped with a three-type three-layer inflation die was used.
Supplied under the following conditions. Both the inner layer and the outer layer are low-density polyethylene (Sumikasen CE255 manufactured by Sumitomo Chemical Co., Ltd.)
9) was supplied under the conditions of a melting zone of 180 ° C and a die temperature of 150 ° C. The resin supplied to each layer is bonded inside the die, and a tubular body having a three-layer sandwich structure (outer layer / intermediate layer / inner layer) is taken off at a take-up speed of 4.2 m / min. A two- and three-layer film having a total thickness of 50 μ and a thickness of 30 μ / the inner layer 10 μ was obtained. For layer B, use linear low-density polyethylene (Sumitomo Chemical Co., Ltd.)
Made, trade name: Exelen VL VL200) thickness 10
A 0 μ, 5 cm square press sheet was used. After the A layer and the B layer are overlaid, the overlaid A layer and the B layer are combined with a polyethylene terephthalate film (10 cm square, 10 cm square) serving as a barrier layer.
After sandwiching the PET with 0 .mu.m thick (hereinafter referred to as PET), the end face of the PET was fixed with aluminum tape, and the color change at 20.degree. C. and 40.degree. C. was observed over time. The superposed A and B layers were initially transparent, but the B layer gradually developed a purple-red color. The discoloration period at this time is shown in Table 1.

Example 2 As a layer B, a PET-based pressure-sensitive adhesive (manufactured by Lintec Co., Ltd.)
Except for using Superstek PET38CLLS0082PET3801), the color change at 20 ° C. and 40 ° C. with time was observed in the same manner as in Example 1. The superposed A and B layers were initially transparent, but the B layer gradually developed a purple-red color. The discoloration period at this time is shown in Table 1.

Comparative Example 1 The procedure of Example 1 was repeated except that a press sheet (100 μm, 5 cm square) of an ethylene-methyl methacrylate copolymer (Aclift WH202 manufactured by Sumitomo Chemical Co., Ltd.) was used as the B layer. The change over time in color tone at ℃ and 40 ℃ was observed. This ethylene-methyl methacrylate copolymer (Acrift WH202, manufactured by Sumitomo Chemical Co., Ltd.) did not have an electron accepting property for developing rhodamine B base, and no color change was observed during the observation period.

Comparative Example 2 As a layer B, a PSA-based pressure-sensitive adhesive (manufactured by Lintec Co., Ltd.)
Except for using Superstick PET38CLWP (3) PET3801), the time-dependent change in color tone at 20 ° C. and 40 ° C. was observed in the same manner as in Example 1. This PET-based adhesive (Lintech Co., Ltd., Super Stick PET38CLWP (3) PET380
1) did not have an electron accepting property to develop rhodamine B base, and no color change was observed during the observation period.

[0020]

[Table 1]

Continuation of the front page (56) References JP-A-62-235562 (JP, A) JP-A-1-150883 (JP, A) JP-A-4-505213 (JP, A) JP-A-6-501770 (JP) , A) (58) Fields investigated (Int. Cl. ⁷ , DB name) G04F 1/00-1/02

Claims (5)

(57) [Claims] When a layer A and a layer B made of a thermoplastic resin or a pressure-sensitive adhesive are overlapped, a distribution coefficient between the two layers [partition coefficient = electron donating color-forming organic compound in the layer B at the time of distribution equilibrium] A layer containing an electron-donating color-forming organic compound in which (concentration of compound) / (electron-donating color-forming organic compound in layer A at the time of distribution equilibrium)] is 0.1 or more and in a decolorized state When,
By superimposing the B layer which has an electron accepting property and is in a decolored state, the color development of the B layer becomes darker with time, and it is possible to indicate the lapse of time since both layers are superimposed. Time indicator to do. 2. The method according to claim 1, wherein the layer A and / or the layer B comprises:
2. The time indicator according to claim 1, wherein the time indicator is a multilayer body having a layer made of a thermoplastic resin or a pressure-sensitive adhesive which is permeable to the electron-donating color-forming organic compound. 3. A layer in which an electron-donating color-forming organic compound is impermeable on one side of each of the A-layer and the B-layer, which are outer surfaces when the A-layer and the B-layer are overlapped. The described time indicator. 4. The time indicator according to claim 1, wherein the layer A and the layer B, which are superposed, are covered and sealed with a barrier layer through which an electron-donating color-forming organic compound cannot pass. 5. The method according to claim 1, wherein the electron-donating color-forming organic compound is selected from the group consisting of rhodamine lactams, fluorans, triphenylmethanephthalides, phenothiazines, indolylphthalides, spiropyrans, leucouramines, and two of these.
The time indicator according to claim 1, wherein the time indicator is a mixture of two or more kinds.