JPS6070339A - Water concentration meter - Google Patents

Abstract

PURPOSE:To measure water concentration in a liquid including water simply and highly sensitively based on the expansion coefficient of a copolymer due to absorption of water, by constituting a meter with a long device, in which graft copolymerization of a hydrophilic vinyl monomer and a macromolecular polymer that is not soluble in water is carried out, and a scale display device. CONSTITUTION:Graft copolymerization of the following materials are carried out: a macromolecular polymer, which is not soluble in water, such as polyolefin, polystyrene, and polyamide; and a vinyl monomer, which has a hydrophilic group such as COOH, NH2, SO3H, PO3H, and OH. With respect to the macromolecular polymer, which is not soluble in water, 30-500wt% of vinyl monomer is used. Thus a rectangular measuring piece 4, which is swelled with water, is prepared. The upper end of the measuring piece 4 is fixed to a scale display plate 1 by a pushing plate 2 and a pin 3. A load 6 is attached to the lower end through a clip 5. Thus a water concentration meter is obtained. The concentration meter is immersed in a solution including water, and the rate of elongation of the measuring piece 4 due to the swelling is measured. In comparison with a calibration curve obtained beforehand, the rate of inclusion of water can be found simply.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is a method for measuring the concentration of water in a water-containing solution. A known method is to measure the specific gravity, refractive index, absorbance, electrophoresis, hydrogen ion concentration, etc. of a water-containing solution and compare these measured values with a calibration curve prepared in advance. .

However, in these conventional methods, the characteristic values of the mixed solution change depending on the type of liquid that is compatible with water.
Not only is the complexity of having to create a test line depending on the liquid that is compatible with water unavoidable, but also an expensive measuring device is required.

In order to solve the above-mentioned problems of the prior art, the inventors of the present invention, as a result of intensive studies, have discovered a kraft copolymer in which a hydrophilic polymer is used as a hese polymer, and a hydrophilic vinyl monomer is graft copolymerized onto the hese polymer. When a coalescence comes into contact with a water-containing bath liquid, it expands depending on the concentration of the water, regardless of the type of liquid that is compatible with the water. They discovered that it is possible to easily know the concentration of water, and completed the present invention1. That is, the water concentration n1 according to the present invention is based on a water-insoluble high molecular weight polymer. , a graft copolymer in which a vinyl monomer capable of imparting hydrophilicity to the polymer is graft copolymerized.

The polymer used in the present invention is not particularly limited as long as it is water-insoluble and does not communicate with a water-containing solution when brought into contact with the water-containing solution. Specific examples include polyolefin, polyamide,
Polyacrylic ester 1 Polymethacrylic ester, polystyrene, polyester, polycarbonate, fluorine-based polymer, polyvinyl chloride, rubber, ethylene-propylene terpolymer, crosslinked polyvinyl alcohol, etc. can be mentioned. This high molecular weight polymer usually has a thickness of about lθ~1
Although it is used in the form of a 00 μm film, it can also be used in other shapes such as strings, nets, cloths, etc.

A vinyl monomer that imparts hydrophilicity is graft copolymerized to these high molecular weight polymers. These vinyl monomers include those having a carboxyl group, amino group, sulfone group, phosphonic group, phosphine group, or hydroxyl group in the molecule, and those that have hydrophilicity by sulfonation or saponification after graft copolymerization, such as styrene or vinyl acetate. You can use whatever you can get as a base.

Those having a carboxyl group include acrylic acid, α-ethyl acrylic acid, β-ethyl acrylic acid, α-pentylacrylic acid, β-nonyl acrylic acid, metasolic acid,
Examples include croton, acid, ichconic acid, maleic acid, etc.
Examples of the acid anhydride include maleic anhydride.

In addition, examples of the vinyl monomer having a 7-mino group include N-vinylphenylamine, allylamine, diallylamine,
Triallylamine, vinylpyridine, methylvinylpyridine, ethylvinylpyridine, vinylpyrrolidone, vinylcarbasol, vinylimidabul, aminostyrene, alkyl 7-minostyrene, dialkylaminostyrene, trialkylaminostyrene, dimethylaminoethyl methacrylate, diethyl 7 minomethacrylate, dicyclohexylaminoethyl methacrylate, di-n-
Propylaminoethyl methacrylate-1, tert-butylaminoethyl methacrylate, diethylaminoethyl acrylate, diethylaminoethyl acrylate, etc. are used, and as the vinyl monomer having 7 quaternized amino groups, the hydrochloride of the vinyl monomer having the above amino group is used. ,
Sulfates, nitrates, phosphates, etc. are used.

Furthermore, examples of vinyl monomers having a sulfone group include styrene sulfonic acid, vinyl sulfonic acid, allyl sulfonic acid, sulfopropyl methacrylate, sulfopropyl methacrylate, 3-chloro-4-vinylbenzenesulfonic acid, and 2-acrylic acid 2-methylpropane. Sulfonic acid, 2-acryloyloxybenzenesulfonic acid, 2-acryloyloxynaphthalene-2-sulfonic acid, 2-methacryloyloxynaphthalene-2-sulfonic acid, etc. are used.

Next, as vinyl monomers having a phosphonic group, allylphosphonic acid, acid phosphoxyethyl methacrylate, 3-chloro-2-acid phosphoxypropyl methacrylate, 1-methylvinylphosphonic acid, 1-phenylvinylphosphonic acid, 2- phenylvinylphosphonic acid,
2-Methyl-2-phenylvinylphosphonic acid, 2-(3
-chlorophenyl)vinylphosphonic acid, 2-diphenylvinylphosphonic acid, and the like.

Examples of those having a phosphine group include allyl phosphinic acid, and examples of those having a hydroxyl group include 0-oxystyrene, 0-vinyl aninol, hydroxyethyl acrylate, and hydroxyethyl methacrylate.

The graft copolymerization reaction of a high molecular weight polymer and a vinyl monomer can be carried out, for example, by irradiating the high molecular weight polymer with energy rays such as radiation or ultraviolet rays, and then bringing it into contact with a vinyl monomer for graft copolymerization. This can be carried out by, for example, a method of bringing monomers into contact and irradiating them with energy beams.

The graft ratio of the graft copolymer obtained in this way is usually about 30 to 500%, but it is necessary to increase the degree of expansion when brought into contact with a water-containing solution to increase measurement sensitivity and to improve mechanical strength. From the point, about 50-30
It is preferable to set it to 0%. Note that this grafting rate is a value calculated using the following formula.

When such graft copolymers are brought into contact with a mixed bath of water and other liquids such as alcohols, carboxylic acids, ketones, ethers, tetrahydrofuran, etc., they will react irrespective of the type of liquid inheriting the water. The lachrymal gold solution expands depending on the water concentration, so by measuring this expanded dimension, the water concentration in the mixed solution can be determined.

In the present invention, in order to increase the degree of expansion when the graft copolymer is brought into contact with a water-containing solution and to improve measurement sensitivity, the graft copolymer is treated with an aqueous solution of 11 um hydroxide, potassium hydroxide, or Contact with hydrochloric acid aqueous solution, etc.
It is preferable to use a branched polymer made of vinyl monomers as a salt.

A length of such a graft copolymer is used in combination with a scale marking.

The present invention is configured as described above, and as will become clear from the following examples, it has a feature that the water concentration in a water-containing solution can be easily determined by contacting it with a water-containing bath liquid. .

Hereinafter, the present invention will be explained in more detail with reference to Examples.

Example 1 A low-density polyethylene film with a thickness of 50 μm is irradiated with an electron beam of 40 me square meters in air.

On the other hand, apart from this, 100 parts of acrylic acid, 0 parts of ferrous chloride
．． 1i, 0.2 parts of hydroquinone and 10 parts of methanol
A solution consisting of 0 parts is prepared, freed of dissolved oxygen, and heated to 74°C.

The above electron beam irradiated polyethylene film was immersed in this heated solution for 1 hour to graft copolymerize polyethylene and acrylic acid to obtain a graft copolymer film with a graft ratio of 230%. This graft copolymer film was heated to 90°C in sodium hydroxide solution.
It was immersed in a 0% by weight hydrolysis solution for 30 minutes, pulled up, and washed with water to obtain a measurement piece (sample 1) containing a branched polymer of acrylic acid as a sodium salt.

In order to know the performance of this measurement piece, the temperature was 20°C, 160%RH.
After leaving it in the atmosphere for one day, a water concentration meter as shown in FIGS. 1 and 2 was produced. In this water concentration meter, the upper end of a measuring piece 4 is fixed by a holding plate 2 and a pin 3 on the upper part of a scale display plate 1 having a scale S on the lower part, and a clip 5 is attached to the lower end of the measuring piece 4. It has a structure in which a load 6 is attached. Load 6 is the cross-sectional area of the graft copolymer 1 - approximately 3
~300 grams is preferred, and in this test 1
I used 00 grams (80 grano・/vui
).

Then, the entire water concentration meter was immersed for 5 minutes in a water-containing solution contained in a transparent container, and the elongation rate due to expansion of the measuring piece 4 was measured by di! The results are shown in Table 1.

The elongation rate of this measurement piece is a value calculated using the following formula.

The measurement piece is a long piece with a width of 10 mm and a dimension (dimension of immersion ijJ) of 30 ('11L) from the upper end fixed with the bottle 2 to the 7th point gripped with the clip 5.

Furthermore, the results of a measurement piece (sample 2) obtained by carrying out the same procedure as sample 1 except that the graft copolymerization time was 20 minutes and the graft ratio was 96% are also shown.

Table 1 The ratio of methanol and glycerin in the water-containing solution consisting of water, methanol, and glycerin in the above table is 1:1 by volume.

Example 2 A measurement piece (sample 3) was obtained in the same manner as sample 1 except that a polyamide film with a thickness of 70 μm was used. The performance of this measurement piece is shown in Table 2. In addition.

The grafting rate was 198%.

Example 3 The same procedure as Sample 1 was carried out except that 1-vinyl-2-hyrrolidone was used as the vinyl monomer, and the grafting rate was 123%.
Obtain a graft copolymer film of ○ Next, this graft copolymer film is immersed in a 5N hydrochloric acid solution heated to 50°C for 60 minutes, taken out, washed with water, and treated with 1-vinyl-2-pyrrolidone. Measurement piece using a branched polymer as a hydrochloride (Fu.

4) was obtained.

The performance of this measurement piece is shown in Table 2.

Example 4 Graft copolymerization time was 17 minutes, grafting rate was 61%
A measurement piece (Sample 5) was obtained by performing all the same operations as Sample 1 except for the following. The performance of this measurement piece is shown in Table 2.

Example 5 Kraft copolymerization time was 130 minutes, grafting rate was 44
The measurement piece (
Sample 6) was obtained. The performance of this measurement piece is shown in Table 2.

Example 6 A measurement piece (sample 7) made of the kraft copolymer used in Example 1 and having a grafting ratio of 230% was obtained. The performance of this measurement piece is shown in Table 2.

Table 2 As can be seen from the above examples, the water concentration meter of the present invention exhibits an elongation rate that corresponds to the water concentration of the water-containing solution, regardless of the liquid that is compatible with water. It has a feature that the water concentration can be easily determined by preparing a calibration curve and comparing the elongation rate with the calibration curve.

[Brief explanation of drawings]

FIG. 1 is a front view showing an example of the water concentration needle according to the present invention, and FIG. 2 is a side view thereof. 1... Scale display board, 4... Measuring piece Patent applicant: Nitto Electric Industry Co., Ltd. Representative Hijikata 3 Part 1 Figure 2

Claims (1)

[Claims] A water concentration meter 0 consisting of a long piece of a graft copolymer based on a water-insoluble high molecular weight polymer and a scale display made by craft copolymerizing a vinyl monomer that can impart hydrophilicity to the polymer.