JPH0618676A - Time indicator - Google Patents

Abstract

PURPOSE:To express the usage history of a product clearly and to manufacture, preserve and the like of the product easily and simply by a method wherein a composition which is composer of a thermoplastic resin and a specific organic compound is molded to a shape whose specific surface area is continuously or noncontinuously different. CONSTITUTION:A time indicator is obtained from a composition which is composed of a thermoplastic resin, a volatile electronaccepting organic compound and an electron- donating coloring organic compound. The composition is melted and molded by an injection molding method, a flow molding method, a compression molding method or the like so as to obtain a shape whose specific surface area is continuously or noncontinuously different. The shape of the time indicator is decided by taking into consideration the volatility of the electron-accepting organic compound, the melting property and the dispersive property of the organic compound in the thermoplastic resin as well a target usage period. For example, in a conical time indicator whose radius on the bottom face is 1cm and whose height is 3cm, its color fades quickly at its vertex part and faces gradually and slowly at its lower part after the passage of time, and its color finally fades totally. At this point of time, it is judged that its life has expired.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a time indicator. More specifically, due to the gradual change in color tone,
The present invention relates to a time indicator capable of visually determining the usage status of a product with a limited validity period and the validity period.

[0002]

2. Description of the Related Art Heretofore, various time indicators have been proposed for visually determining the effective period of a product having a limited effective period by utilizing color tone change. (For example, Japanese Patent Laid-Open No.
-290591, JP-A-1-230504, JP-A-63
-60901, JP-A-62-142564).

[0003]

However, it is difficult to determine the end point of use of these time indicators due to the gradual change in color tone, that is, when the product is in the early stage, in the middle stage, or when the end of use occurs. There are problems such as not knowing the usage history.

[0004]

As a result of intensive studies to solve the above-mentioned problems, the present inventors can clearly show the usage history of the product and easily determine the end point of usage. The present invention has been accomplished by finding a time indicator that can be manufactured, stored and used very easily.

That is, according to the present invention, a composition obtained by melt-kneading a thermoplastic resin, an electron-accepting organic compound having volatility, and a hardly volatilizing electron-donating color forming organic compound has a continuous specific surface area. The present invention provides a time indicator formed by differently or continuously forming different shapes.

The time indicator of the present invention exhibits a discoloring action when an electron-donating color-forming organic compound in a color-developing state in the presence of an electron-accepting organic compound gradually disappears as the electron-accepting organic compound volatilizes. It is used as a time indicator, and it is possible to clearly show the usage history of the product by utilizing the fact that the degree of discoloration differs depending on the part.

In the time indicator of the present invention, examples of the shapes having different specific surface areas continuously or discontinuously include the following ones. Cones, pyramids, wedges, stepped shapes, tops; cones or pyramids with overlapping vertices or bottoms, shaped bodies such as hourglasses and gourds with different diameters, and different diameters Shapes such as two or more spheres or elliptical spheres (for example, a polished shape), spheres with different diameters connected like beads, and those with these shapes cut with an appropriate cross section. The shape may have different thickness depending on the part.

The time indicator of the present invention comprises a composition comprising a thermoplastic resin, a volatile electron-accepting organic compound, and an electron-donating color-forming organic compound, prepared by injection molding, blow molding, compression molding or the like. It can be easily produced by a usual thermoplastic resin molding method by melt-molding continuously or discontinuously into a shape having different specific surface areas depending on the site of the molded body. The shape of the time indicator is
The shape should be determined in consideration of the volatility of the electron-accepting organic compound, the solubility in the thermoplastic resin, the diffusibility, and the intended period of use, and the specific surface area may vary continuously or discontinuously depending on the site of the molded product. There is no particular limitation.

Generally, the greater the difference in specific surface area between the parts of the molded article, the greater the volatility of the electron-accepting organic compound, and the less the diffusibility of the electron-accepting organic compound in the thermoplastic resin, The concentration of the electron-accepting organic compound after aging greatly varies depending on the site, and as a result, the degree of decoloring varies greatly depending on the site, and the usage history of the product can be more clearly shown. The compounding amounts of the volatile electron-accepting organic compound and the electron-donating color-forming organic compound can be arbitrarily changed depending on the thermoplastic resin used and in consideration of the desired color tone and effective period. The amounts are 0.001 to 50 parts by weight and 0.0001 to 5 parts by weight, respectively, with respect to 100 parts by weight of the plastic resin.

The compounding amounts of the volatile electron-accepting organic compound and the electron-donating color forming organic compound are each 0.001.
If the amount is less than 0.001 part by weight, the discoloration is unclear, and if the amount exceeds 50 parts by weight and 5 parts by weight, discoloration easily occurs due to bleeding on the surface of the composition, which is not preferable.

In the present invention, the electron-donating color-developing organic compound is colored at room temperature in the presence of the electron-accepting organic compound and disappearance of the electron-accepting organic compound or decolorization due to the presence of the electron-donating organic compound. Is a compound that reversibly occurs in, and is not particularly limited as long as it is a substance that is difficult to volatilize, various conventionally known compounds, for example, rhodamine lactams,
Fluoranes, triphenylmethanephthalides, phenothiazines, indolylphthalides, spiropyrans,
Compounds such as leuco auramines can be used. More specifically, rhodamine B base, N-phenylrhodamine lactam, crystal violet lactone, malachite green lactone, 1,3-dimethyl-6-diethylaminofluorane, 2- (2-chloroanilino) -6-dibutylaminofluorane. , 3,7-bis (dimethylamino) -10-benzoylphenothiazine, N-3,3-trimethylindolinobenzospiropyran, ethyl leucomethylene blue and the like. The above-mentioned electron-donating color-forming organic compound alone is 2
It can be used with more than one seed.

The electron-accepting organic compound in the present invention may be any one as long as it has volatility at room temperature or under heating, and any compound that volatilizes moderately under desired use conditions can be appropriately used. For example, resorcin, cresol, phenol such as naphthol, phenolic acid such as salicylic acid, benzyl alcohol, alcohols such as 1-octanol, stearic acid, carboxylic acid such as myristic acid,
Parachlorometaxylenol, orthophenylphenol, 3-methylisopropylphenol, 3-aceto-6-methyl-2-pyrronone and the like having antifungal activity are used alone or in combination of two or more. In particular, when the volatile electron-accepting organic compound in the present invention is a drug exhibiting antifungal activity, the antifungal agent can directly know the residual state of the actual antifungal activity and the end point of use without error. Various indicators can be provided.

The thermoplastic resin in the present invention can be heat-processed below the thermal decomposition temperature of the volatile electron-accepting organic compound and the electron-donating color forming organic compound, and does not cause the electron-donating color forming organic compound to develop color. If there is, for example,
Branched low-density polyethylene, linear low-density polyethylene which is a copolymer of ethylene and an α-olefin having 4 to 12 carbon atoms, high-density polyethylene, a copolymer of ethylene and / or butene-1 and propylene, vinyl acetate And / or a copolymer of acrylic acid ester and ethylene,
Examples include polypropylene, olefin-based thermoplastic resins, styrene-butadiene rubber, ethylene-propylene-diene rubber, and other synthetic rubbers, vinyl chloride-based thermoplastic resins, polyesters, nylons, and the like, which may be used alone or in combination of two or more. You can

In selecting the thermoplastic resin in the present invention, the decoloring at the end point of use may be insufficient, so that additives, plasticizers, catalyst residues, etc. that cause the electron-donating color-forming organic compound to develop color. Must have no electron-accepting component. Further within the range that does not impair the object of the present invention, fungicide, fungicide, herbicide, plant growth regulator, pheromone, juvenile hormone pseudo-organic compound, insecticide, repellent, deodorant, aromatic, Pharmaceuticals,
Antioxidants, ultraviolet absorbers, light stabilizers, antiblocking agents, fillers, transpiration regulators, fragrances, dyes, pigments and the like can be used as appropriate.

For example, when a yellow pigment and an electron-donating color-developing organic compound that develops red are used, the reddish brown color at the beginning of use changes to yellow at the end point. The discoloration period of the time indicator of the present invention is several hours to several years depending on the use situation, depending on the volatility of the electron-accepting organic compound, the diffusibility of the electron-accepting organic compound in the thermoplastic resin, and the shape change. The period can be set arbitrarily.

[0016]

According to the time indicator of the present invention, it is possible to easily visually determine the usage status and the effective period of a product by the change of the color tone.

[0017]

The present invention will be described in more detail with reference to examples, but the present invention is not limited thereto. Example 1 As a thermoplastic synthetic resin, ethylene-methyl methacrylate copolymer (Acryft WH202 manufactured by Sumitomo Chemical Co., Ltd.)
100 parts by weight, 3 parts by weight of 3-methyl-4-isopropylphenol as a volatile electron-accepting organic compound, and rhodamine B base (manufactured by Taoka Chemical Industry Co., Ltd.) as an electron-donating color-forming organic compound 0.04 A part by weight was melted and kneaded in a closed-type pressure kneader (manufactured by Moriyama Seisakusho) by utilizing shearing heat generation, and then hot cut while feeding into an extruder to obtain pellets. Injection molding was performed using the obtained pellets to obtain a time indicator of the entire shape shown in FIG. (Radius of bottom 1
The specific surface area of this time indicator is the largest at the apex except for the cross section (bottom surface), and the smaller the specific surface area toward the lower part, the more continuous the surface area of the molded body excluding the bottom surface. The shapes have different specific surface areas. Space volume 9m adjusted to temperature 25 ℃ and humidity 40% RH
³ Place the obtained time indicator with the bottom face down on the desk laid with an aluminum plate in the constant temperature and humidity chamber (glue)
Then, the change in color tone was observed with the naked eye after a certain period of time.
After a lapse of time, the time indicator was faster at the top of the time indicator and later at the lower part, and the reddish-purple color became gradually thin, and the entire color disappeared after 18 months. Observation at 5 months after the start of the test revealed that approximately 1/3 of the vertex was decolored and almost transparent, and the lower part was darker reddish purple and approximately 1/3 of the bottom.
The part of shows a magenta color almost unchanged from the initial stage. From this observation, the usage history, that is, about 1 of the life at this point
It was possible to easily judge that / 3 had passed.

Example 2 Example 1 was repeated except that 11 parts by weight of 1-ethynyl-2-methyl-2-pentenyl chrysanthemate (Vaporthrin manufactured by Sumitomo Chemical Co., Ltd.), which is a volatile insect repellent, was added. I got a time indicator in the same way as. The color of the obtained time indicator was almost red purple as in Example 1. As a result of observing a change in color tone with time with the naked eye in the same manner as in Example 1, the same color tone change as in Example 1 was obtained except that the color after erasing was a very pale orange, and the use history was changed. I could easily judge. The remaining rate of 1-ethynyl-2-methyl-2-pentenyl chrysanthemate in this time indicator was 70% after 5 months from the start of the test and 2% after 18 months.
Met.

Example 3 A pellet obtained in the same manner as in Example 1 except that 2 parts by weight of orthophenylphenol was used as the volatile electron-accepting organic compound was injection-molded into the shape shown in FIG. , Got the time indicator. The specific surface area of this time indicator, except the vicinity of the cross-section, thickness 1mm portion of about 20 cm ^-1, thickness 2mm section of about 10 cm ^-1, the thickness 3m
The m portion is about 6.7 cm ^-1 , and the specific surface area is discontinuously different depending on the site of the molded body. This time indicator and a 100 μm-thick polyethylene film (Sumikasen F208-0 manufactured by Sumitomo Chemical Co., Ltd.) shown in FIG. It was hung up in a constant temperature and humidity chamber under the same conditions as in Example 1, and the change in color tone after aging was visually observed. Immediately after hanging, the time indicator was entirely reddish purple, and the characters written on the polyethylene film could not be read. 4 after starting the test
In the observation at the end of a month, the part with a thickness of 1 mm became almost transparent, and the letters “early use” written on the polyethylene film could be easily discerned, but other parts had a reddish purple color compared to the initial part. I couldn't read the letters. After that, when 6 months passed, a thin "medium-term" character became readable from the site having a thickness of 2 mm, and this site became almost transparent after 8 months passed. At the end of 8 months, the characters can be read thinly even in the part with a thickness of 3 mm.
After 2 months, the entire color disappears and becomes transparent.
The character of was also easily distinguishable.

Comparative Example 1 A time indicator was obtained in the same manner as in Example 1 except that the shape of the cylinder was a cylinder having a bottom radius of 1 cm and a height of 3 cm (the specific surface area is the same except for the cross section regardless of the part). After molding and observing the change in color tone after aging under the same conditions as in Example 1, the decoloring near the cross section (upper surface) of the cylinder was faster than the other parts, but the other parts were uniform throughout. Thinning,
The whole thing became transparent after 20 months. In this case, it can be used as a time indicator for about 20 months.
Unlike ~ 3, it is difficult to determine the end point of use because the color tone changes gradually regardless of the part, and whether the current use is in the early stage, the middle stage, or when the use is finished The usage history could not be determined.

Comparative Example 2 A time indicator was molded in the same manner as in Example 3 except that the shape was a sheet having a size of 5 cm × 9 cm and a thickness of 1 mm (the specific surface area was the same regardless of the site except for its cross section). When the change in color tone after aging was observed under the same conditions as in Example 3, the decoloring near the cross section of the sheet was faster than other parts, but the other parts were uniformly thinned as a whole.
After a month, the whole thing became transparent. Also in this case, similarly to Comparative Example 1, it was difficult to determine the end point of use, and the use history could not be determined.

[0022]

[Brief description of drawings]

FIG. 1 is one embodiment of the time indicator of the present invention (Examples 1 and 2).

FIG. 2 is one embodiment of the time indicator of the present invention (Example 3).

FIG. 3 is one embodiment of the time indicator of the present invention (Example 3).

Claims (8)

[Claims] 1. A composition obtained by melt-kneading a thermoplastic resin, an electron-accepting organic compound having volatility, and a hardly volatilizing electron-donating color forming organic compound, and having a specific surface area which is continuous or discontinuous. Indicator that is molded into different shapes. 2. A composition obtained by melt-kneading a thermoplastic resin, an electron-accepting organic compound having a volatility, and a hardly volatilizing electron-donating color-forming organic compound at a site excluding a cross section of a molded article. , A time indicator formed by continuously or discontinuously forming different specific surface areas. 3. 100 to 100 parts by weight of a thermoplastic resin, 0.001 to 50 parts by weight of a volatile electron-accepting organic compound, and 0.0 to a hardly volatile electron-donating color forming organic compound.
The time indicator according to claim 1 or 2, which is 001 to 5 parts by weight. 4. The time indicator according to claim 1, wherein the thermoplastic resin is polyolefin, synthetic rubber, vinyl chloride resin, polyester, nylon, or a mixture of two or more thereof. 5. A hardly volatile electron-donating color-forming organic compound is a rhodamine lactam, a fluorane, a triphenylmethanephthalide, a phenothiazine, an indolylphthalide, a spiropyran, a leukoauramine, or The time indicator according to claim 1 or 2, which is a mixture of two or more of these. 6. A volatile electron-accepting organic compound,
Resorcin, cresol, naphthol, salicylic acid, benzyl alcohol, 1-octanol, stearic acid,
The time indicator according to claim 1 or 2, which is myristic acid, parachlorometaxylenol, orthophenylphenol, 3-methylisopropylphenol, 3-aceto-6-methyl-2-pyrronone, or a mixture of two or more thereof. 7. The time indicator according to claim 1, further comprising an organic compound having a medicinal effect. 8. The method of using the time indicator according to claim 1, wherein the time indicator is used in combination with an organic compound having a medicinal effect.