JPS60178362A - Ph measuring ink composition and tester formed by using the same - Google Patents

Abstract

PURPOSE:To enhance sensitivity and indication capacity, by dissolving or dispersing a reagent composition, which consists of a pH indicator, a quaternary ammonium or amine salt, a binder and a water absorbable powder, in a solvent. CONSTITUTION:A reagent composition is formed of a pH indicator, a guaternary ammonium or amine salt such as alkyltrimethyl-ammonium, a binder consisting of a water soluble high-molecular compound for stabilizing color formation and a water insoluble high-molecular compound for preventing the elution of the formed color, and a water absorbable powder and dissolved or dispersed in a solvent such as aromatic hydrocarbon to constitute a pH measuring ink composition. This composition is used in a state applied to a support such as paper.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field of the Invention The present invention relates to an ink composition suitable for forming a test body for measuring the pH of a solution, particularly a body fluid such as urine, blood, lymph, etc. Regarding the tested specimen.

Technical background of the invention and its problems It is difficult to quickly, easily and accurately know the pn of a solution in many chemical environments. In addition, knowing the pH of solutions, especially body fluids such as urine, helps to accurately determine the presence or absence of proteins in body fluids, as well as the possibility of bacterial silver that can cause nephritis, cystitis, etc. This helps in confirming the gender.

Conventionally, pH test paper manufactured by impregnating a water-absorbing support such as filter paper with an aqueous solution containing multiple pH indicators has been widely used. For example, the pI of a solution has been widely used.
Japanese Patent No. 1200 proposes a pH test piece in which an absorbent carrier is impregnated in a solution containing a pH indicator composition. However, this test piece required many manufacturing steps, which was disadvantageous in terms of process control and resulted in high manufacturing costs. Therefore, pH test pieces that can simplify the manufacturing process and are suitable for mass production have also been proposed.

For example, Tokko Sho'lll-, 239! ; Publication No. J proposes a pH test piece consisting of a plurality of pH indicators and adsorbent powder adhered to a support, and also published by Jitsukasho! ”)−
No. 77767 also proposes a pH test piece having a pH measurement area formed by printing a pH measurement ink composition containing a pH indicator on a support. However, such pH test pieces have the following problems.

(a) When a test piece is immersed in a test liquid and then dried, a noticeable fading phenomenon of the developed color is observed.

(b) When the test piece is immersed in the test liquid, the indicator may be eluted into the test liquid, making it difficult to obtain clear coloration.

(e) It takes time for the test piece to develop color when it is immersed in the test liquid.

In order to solve the above-mentioned problems, the present inventors have found that the above-mentioned problems can be solved by using an ink composition for research measurement and coating it on a support. Ta.

OBJECTS OF THE INVENTION AND SUMMARY OF THE INVENTION The present invention attempts to solve the drawbacks associated with the prior art and has the following objects.

(8) To provide a pH tester having excellent sensitivity and indicating performance and an ink composition therefor.

(b) - To provide a pI (test specimen and an ink composition therefor) in which the obtained color shows little fading after drying.

The ink composition for pH measurement according to the present invention includes a pH indicator,
A reagent composition comprising a grade ammonium salt or amine salt, a binder, and a water-absorbing powder is dissolved or dispersed in a solvent, preferably a non-aqueous solvent. has a pH measurement area formed by coating a support with a pH measurement ink composition having the above composition.

3. Detailed Description of the Invention Below, first, the ink composition for pH measurement used in forming the test object (p) according to the present invention will be specifically described.

b) Principle Preferably, a plurality of types of indicators whose color tone changes depending on the pH are combined, and the pH of the test liquid is measured by determining the color tone of the indicators.

pH indicator: Any indicator can be used as long as it changes color depending on the hydrogen ion concentration of the test solution.

Furthermore, by appropriately selecting or combining a plurality of types of indicators, it is also possible to measure a wide pH range.

For example, if a combination of methyl hood and bromothymol blue is used as a pH indicator, it is possible to accurately determine the pH in the range of PH' to -2.

The pH indicator is o, oi with respect to the solid content of the ink composition.
Preferably present in an amount of ~o,r% by weight.

No) By blending an appropriate amount of ψ class ammonium salt into the ≠ class ammonium salt or amine salt reagent composition, -
The fading phenomenon of brightly developed colors over time is greatly suppressed,
And vivid colors can be obtained.

As the high grade ammonium salt, alkyltrimethylammonium salt, alkyldimethylbenzylammonium salt, sapamin type ammonium salt, etc. are used. Among these, alkyldimethylbenzylammonium JjX
b″-particularly preferred.

Note that instead of the ≠-grade ammonium salt, primary amine salts, secondary amine salts, and tertiary amine salts or polyethison glycol, which are known as cationic surfactants, can also be used.

These ≠ grade ammonium salts or amine salts have a content of 0.0% based on the solid content of the ink composition. Preferably it is present in an amount of % Or − /weight Mk.

2) Binder The binder is used to enable the above-mentioned reagents and water-absorbing powder to be formed on the support, and does not affect the components and pH of the test solution, and also does not affect the elution of the reagents. It is required that the color reaction is prevented and the color reaction is not hindered.

'Binders suitable for pH measurement ink compositions that meet these requirements are water-soluble polymers that have a color-developing effect that does not interfere with the color development of the pH indicator at all, but also stabilizes the resulting color. It is preferable that the compound is formed by combining a water-insoluble polymer compound with a film-forming ability that does not hinder the color development of the pH indicator and also has the effect of preventing the elution of reagents into the test liquid. .

The above-mentioned water-soluble polymer compounds include (1) Kansho starch, potato starch, konnyaku powder, funori,
Agar, sodium alginate, molasses, tongarogum, gum arabic, dextran, V-pan, glue,
Natural hydrophilic polymer compounds such as gelatin, casein, and collagen; (II) Cellulose derivatives such as methyl cellulose, hydroxypropyl cellulose, hydroxyethyl cellulose, and carboxymethyl cellulose; semisynthetic hydrophilic polymer compounds such as carboxymethyl starch and dialdehyde starch derivatives; and (tiD) synthetic polymer compounds such as polyvinyl alcohol, polyacrylamide, polyvinylpyrrolidone or their copolymers, sodium polyacrylate, and polyethylene oxide. Synthetic polymer compounds such as cellulose derivatives and polyvinylpyrrolidone are preferred.

On the other hand, the above-mentioned water-insoluble polymer compounds having a skin-forming structure are used, and celluloses such as H(+) nitrocellulose, cellulose acetate, ethyl cellulose, and cellulose acetate butyrate are used.
ff4 JjW, (1) Horiester 4fiJ]
L-alkyd resin, polyurethane resin, epoxy Iil resin, acrylic resin, vinyl chloride resin, vinyl chloride copolymer resin, polyvinyl butyral, polyvinyl acetate emulsion, vinyl acetate copolymer (6'l vinyl-acrylic acid ester, etc.) emulsion, acrylic Acid ester copolymer emulsion, pinylic chloride.

Examples include den copolymer emulsion, epoxy (IIJ) fat emulsion, and synthetic rubber latex.

Among these, urethane resin and polyvinyl butyral,
This is preferable because it does not adversely affect the color reaction of the pH indicator.

The binder has an amount of approximately 1tr4 based on the solid content of the ink composition.
It is preferable to exist in a joint relationship.

e) The water-absorbing powder is blended into the reagent composition71. By doing so, it acts to promote contact between the test liquid and the pH indicator and to promote the color reaction of the indicator.

If you use such water-absorbing powder, 10 is water and 1't! I!
In this case, those exhibiting extreme acidity or alkalinity are not preferred, and those exhibiting high whiteness are preferred. Specifically, kaolin, synthetic silica, glass, cellulose block, microcrystalline cellulose, ion exchange cellulose, ion exchange resin, calcium carbonate, magnesium carbonate, aluminum silicate, etc. can be used.

The water-absorbing powder has a ratio of jo − to the solid content of the ink composition.
It is preferable that the thread is present in the amount of vo M%.

f) Solvent The solvent is preferably one that can uniformly and stably dissolve or disperse the above reagents, especially the binder. Solvents that do not meet this requirement include aromatic hydrocarbons, aliphatic hydrocarbons,
Nonaqueous solvents such as esters and alcohols, or mixtures of water and other solvents are used.

However, it is preferable to use a non-aqueous solvent because the drying process of 1& in which the ink composition for pH measurement is applied onto a support can be carried out at a low temperature and in a short time. When a non-aqueous solvent is used, there is also the effect that deterioration of the liquid quality of the reagent composition due to residual moisture can be prevented.

g) Other ingredients In some cases, in addition to the above ingredients, small amounts of wetting agents such as nonionic surfactants, ionic surfactants, cationic surfactants, zwitterionic surfactants, polyethylene glycols, etc. may be added. , it can also be blended into a reagent composition for pH measurement. This wetting agent helps disperse each reagent,
It can promote the formation of a uniform reagent layer and improve water wettability. The wetting agent is Q based on the solid content of the reagent composition.
, is preferably present in an amount of from 0 to 0.

To make the color tone of the indicator more visible, a background dye such as oil yellow may be added.
.

The ink composition for pH measurement as described above is applied onto a support to form a constant pH region of 111, thereby obtaining a specimen according to the present invention. As the application technique, a printing method, a coating method (for example, roll coating, spray coating, solid coating), etc. can be used. In J of the present invention, since it is preferable that the ink composition has a relatively large amount of coating and a constant coating area, the ink composition is applied onto the support by a silk screen printing method, an intaglio printing method, a gravure printing method, etc. It is preferable to provide the

The coating 'Bk varies depending on the strength of the ink composition, but is generally preferably λ to 1 roy/m' (dry).

The support is preferably a material that does not react with the reagent composition and does not inhibit the coloring of the reagent, and specifically, for example, paper, synthetic paper, nonwoven fabric, synthetic resin film, or paper and synthetic material. 10 (a laminate with a fat film is used).

The pH tester according to the present invention, in which a p Ha++1 constant region is provided on such a support, may be formed in the form of a stick, a roll, a tape, or the like. Alternatively, the support itself can be formed into a shape such as a pot, test tube, dish, tray, or dropper (such that the test liquid can be sampled), and a pH measurement area is provided on the support. pI according to the invention (may also be used as a test object).

Effects of the Invention Since the pH test object according to the present invention is formed using an ink composition for pH measurement containing a primary ammonium salt or amine salt and a specific binder, it has the following effects.

a) After being immersed in the m' solution to develop color, the developed color fades less over time.

b) The PH measurement area has some degree of water resistance;
There is little dissolution of the indicator into the wt test sample solution.

C) Color development is rapid and the resulting color tone is clear.

d) Since the PH measurement area can be formed by direct coating on the support or by a printing method, it is advantageous for mass production and the process can be shortened to 5 f.

Example/ An ink composition for pH measurement having the following composition was prepared.

Methyl red sodium salt 0.07 Parts by weight Promomethyl blue O0/3 Alkylbenzyldimethylammonium chloride o, ip (Kakko Soap, Sanizol) Microcrystalline cellulose 36 (Non-chemical, Avicel SF) Ethylseronlupe t.

After sufficiently finely dispersing the above composition using a homomixer, it was printed on a white polystyrene sheet having a thickness of 230 μm to form a rectangular shape having a side of j mm by screen printing. The screen plate used had a total thickness of 130 μm, including the thickness of the lOO mesh, the resist, and the screen thickness.

The obtained printed matter was dried at &j'C for 30 minutes and then cut into stick shapes to obtain test pieces for pH measurement.

These sticks were tested with known pH solutions. The coloration observed in each stone at different hydrogen ion concentrations was as follows. pHj Orange pH 4 Yellow pH 7 Yellow-green pHr Green pH 9 Yt The coloration was uniform and clear, and could be easily distinguished within the range of pHj to 2. In addition, no elution of pigments or other substances from the test body fluid was observed, and the color tone did not change even if the mouse was left indoors for one minute after immersion, and even after the reagent layer was left to dry for several hours, the pH remained unchanged. Other than that, the color tone remained almost the same.

In addition, the pH can be accurately measured even in solutions such as urine to be tested. Even after long-term storage (6 months/year) of the specimen tested by Kakitoko, there was no change in coloring performance, which was poor.

In addition, the above ink composition for pH measurement is stable and can be printed by simply redispersing it even after one month has passed after preparation.
The test specimen obtained also showed excellent performance.

Ink composition for pH measurement of Example/Example/Example/Example/Example/Example/Ink composition for pH measurement -!t
A test body for pH measurement was manufactured in the same manner as in Example except that 70) was replaced.

The obtained test specimen for pH measurement showed clear and stable coloration in the pH range of 2 to 2, as in Example.

Comparative Example (Effect of quaternary ammonium salt) A specimen was produced in the same manner as in Example 1, except that Sanizol was added to the pH measuring ink composition of Example 1.

After this specimen was immersed in the test solution, the color developed over time changed as follows.

Immediately after pH immersion 20 minutes after immersion Orange Orange 6 Orange Yellow Orange 7 Yellow-green Yellow Dark green Yellow Ta Blue After yellow coloring, as the reagent layer dried, fading was especially remarkable in the alkaline region.

Comparative Example λ〉 (Effect of water-soluble polymer compound binder) An ink composition for pH measurement having the following composition was prepared in the same manner as in Example 1, and then printed on a support and tested for pH measurement. The body was manufactured.

Methyl red sodium salt θ, 07 Juzuki part promothymol blue 0.30 Ethyl cellulose j (Percules N-jtO) Microcrystalline cellulose 36 (Asahi Kasei, Avicel 5F) n-Butyl alcohol Tatoluene SO The obtained test specimen was The time it took for color to develop after being immersed in the sample solution was about 1 minute, and discoloration was observed after 11, -3 minutes.

Applicant's agent Kiyoshi Inomata

Claims (1)

[Claims] /, pH indicator, high grade ammonium salt or amine salt,
An ink composition for pH measurement, characterized in that a reagent composition comprising a binder and a water-absorbing powder is dissolved or dispersed in a solvent. 8. The ink composition according to claim 7, wherein the binder comprises a water-soluble polymer compound having a color developing effect and a water-insoluble polymer compound having a film-forming ability. 3. The ink composition according to claim 2, wherein the water-soluble polymer compound having a color developing effect is hydroxyethyl cellulose or polyvinylpyrrolidone. Hiroshi The ink composition according to claim 2, wherein the water-insoluble polymer compound having film-forming ability is a urethane resin or a polyvinyl butyral resin. An ink composition for pH measurement, in which a reagent composition consisting of t-pI (indicator, a high-grade ammonium salt or amine salt, a binder, and a water-absorbing powder) is dissolved or dispersed in a solvent, is coated on a support. A detecting body for pH measurement characterized by having a pH measurement region: t. A patent in which the binder comprises a water-soluble polymer compound having a color developing effect and a water-insoluble polymer compound having a film-forming ability. Detector according to claim 5. 7. Detector according to claim 6, wherein the water-soluble polymer compound having a color developing effect is hydroxyethyl cellulose or polyvinylpyrrolidone. r. Film formation. 7. The detection object according to claim 6, wherein the water-insoluble polymer compound having the above-mentioned ability is a urethane resin or a polyvinyl butyral resin.