JPH0676905B2 - Water level indicator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention recognizes the fact that the display part absorbs water and peels off, falls off, or collapses upon contact with water, thereby recognizing the water level or the fact of contact with water. It is related to the water level indicator.

(Prior Art) Conventionally, the water level indicator or the water contact position indicator has been used to confirm the maximum water level in rivers, lakes, groundwater, agricultural water, sewers, drains, etc. It was required for the purpose of grasping the damage situation of inundation of stored goods at that time or confirming contaminants due to inundation.

However, for that purpose, an observer is required to be resident, expensive measuring equipment is required, and in many cases expensive electric equipment and power source are required.

(Problems to be solved by the invention) Therefore, in order to be simple, inexpensive, and widely used, an unmanned water level indicator which can be used anywhere has been demanded.

As a result of various studies on the method of indicating the water level in order to satisfy the above condition, the inventors have found that a water-swellable resin attached to a rigid base material in a specific state absorbs water and expands when it comes into contact with water. The present invention has been completed by finding that it causes a change in shape or form such as peeling or peeling.

(Means for Solving Problems) That is, according to the present invention, a coloring substance containing a water-swelling resin which is peeled off, dropped off or disintegrated when brought into contact with water is provided on a vertically long rigid base material at regular intervals. It is a water level indicator for confirming the water level in a water area, which is characterized by being applied, fused or attached in a horizontal stripe pattern.

(Function) A coloring substance containing a water-swellable resin is applied, in a horizontal stripe pattern at a certain interval on a rigid substrate together with a synthetic resin, a rubber-like substance, a plasticizer, a coloring agent, and a surfactant, if necessary, by fusion bonding. When attached to water, the wetted part absorbs water, swells, peels off, falls off and collapses, so that the highest water level reached in the past can be easily recognized with the naked eye. Can be done.

(Preferred Embodiment) The present invention will be described in more detail. In the present invention, the water-swellable resin is a resin that does not dissolve in water but swells by absorbing water, and is, for example, chemically or physically crosslinked. Polymers having a portion, for example, agar, powders such as gelatin, starch-sodium polyacrylate graft product,
Starch-polyacrylonitrile grafted product, cellulose-polyacrylic acid grafted product, vinyl alcohol-sodium acrylate copolymer, vinyl alcohol-sodium methacrylate copolymer, sodium polyacrylate, sodium salt of carboxymethyl cellulose,
It is a chemically crosslinked product or a physically crosslinked product of a water-soluble resin such as polyethylene oxide.

Of these, water-swellable resins in which a hydrophobic polymer chain or copolymer chain is bonded to a polymer or copolymer having a hydrophilic group in the form of a block copolymer or a graft copolymer are preferred.

A particularly suitable water-swellable resin is (hydrophobic segment)-
It has a bonding form of (hydrophilic segment)-(hydrophobic segment), and a typical example thereof is (polystyrene)-(polybutadiene)-, as shown in Examples below.
It is obtained by adding thioglycolic acid, maleic anhydride, acrylic acid, methacrylic acid or the like to the double bond of the block copolymer of (polystyrene) or by addition-polymerizing it, and then neutralizing it with an alkali.

In addition, the water-swellable resin having this binding method and the method for producing the same are described in Japanese Patent Application Laid-Open No. 54-135836 disclosed by the applicant of the present application. Although this type of water-swellable resin hardly elutes in water, it has an extremely high degree of water swelling and swelling power, and has high releasability from the substrate.

Further, it can be dispersed in various organic solvents such as toluene, xylene, cyclohexane, methyl ethyl ketone, dioxane, and methanol, and the dispersion liquid can quickly form a uniform dispersion liquid with a solution type binder.

As the synthetic resin used as the binder of the water-swellable resin in the present invention, homopolymers or copolymers of acrylic acid esters and methacrylic acid esters, ethylene-vinyl acetate copolymers, ethylene-vinyl acetate-vinyl alcohol copolymers. , Butyral resin, polyvinyl acetate, vinyl chloride resin, vinyl chloride-vinyl acetate copolymer, polyamide, polyester, polyurethane, alkyd resin, cellulose acetate, cellulose acetate butyrate, shellac, rosin ester, etc. Known as natural rubber, recycled rubber, chlorinated rubber, cyclized rubber, styrene-butanediene rubber, butanediene-nitrile rubber, isoprene rubber, chloroprene rubber, ethylene-propylene rubber, butyl rubber, acrylic rubber, urethane rubber, silicone rubber, etc. The ones listed here are The copolymers al, random copolymers, A-B type and A-B-A type block copolymer of are included.

As the plasticizer, dibutyl phthalate, dioctyl phthalate, dioctyl adipate, dioctyl sebacate, tricresyl phosphate, process oil, etc.,
Conventionally known ones can be mentioned.

Further, in the present invention, it is necessary to be able to recognize the water contact position, and it is preferable to use a colorant in combination in order to make the water contact position more clear. Further, the color of the colorant is preferably a color which can be clearly distinguished from the color of the base material, and it is preferable to use colorants of all colors such as white, blue, green, brown and black. I can. Known colorants such as water-soluble dyes, oil-soluble dyes, disperse dyes, organic pigments and inorganic pigments can be used as these colorants.

For example, as the dye, monoazo, polyazo, azo such as metal complex salt azo, anthraquinone, indigo / thioindigo, phthalocyanine, triphenylmethane,
Examples include xanthene-based, dioxanthin-based, methine-based, naphthalimide-based, perinone-based and the like. Further, as the organic pigment, phthalocyanine-based, azo-based, condensed azo-based, anthraquinone-based, perinone-perylene-based, indigo-thioindigo-based, isoindolinone-based, azomethineazo-based, dioxazine-based, quinacridone-based, aniline black-based,
Triphenylmethane-based, xanthene-based, and carbon black-based, inorganic pigment-based titanium oxide-based,
Examples include iron oxide-based, iron hydroxide-based, chromium oxide-based, spinel-type fired pigments, lead chromate-based, chromate vermilion-based, and navy blue-based.

As the surfactant, polyethylene glycol alkyl ether, polyethylene glycol alkyl aryl ether, polyethylene glycol higher fatty acid ester, sorbitan higher fatty acid ester, polyethylene glycol sorbitan higher fatty acid ester, polyethylene glycol-polypropylene glycol-polyethylene glycol block copolymer, polyethylene glycol higher ester Nonionic activators such as aliphatic amines, their sulfuric acid esters, phosphoric acid esters, higher fatty acids, alkyl sulfonic acids, alkylaryl sulfonic acids, alkyl sulfates, ammonium salts of acids of alkyl phosphates, alkali metal salts, mono or Anion activators such as polyamine salts, alkanolamine salts, and morpholine salts,
And cationic active agents such as higher aliphatic primary, secondary, tertiary amine and quaternary ammonium and their hydrochlorides, acetates, higher fatty acid salts such as stearic acid and oleic acid.

The water level indicator of the present invention is made by applying or sticking a water-swellable resin to a rigid base material together with other substances as necessary. The rigid base material is selected according to the purpose of use, and is, for example, a rigid material having a thin plate shape, a thick plate shape, a column shape, a rod shape, a pipe shape, or even a part of an existing building. Good.

As the material of the base material, in the case of plastic, for example, vinyl chloride resin, styrene resin, acrylonitrile-styrene resin, acrylonitrile-butanediene-
Molded products such as styrene resin, polyethylene, polypropylene, nylon, polycarbonate, polyester, unsaturated polyester, acetal resin, acetyl cellulose, phenol resin, etc., and other rigid molded products such as wood, stone, concrete, asphalt, etc. , Buildings, etc.

The coating material containing the water-swellable resin is prepared in the same manner as a conventionally known coating material or paint preparation method. However, since the original purpose is to absorb water in contact with water, swell, peel, drop off, and disintegrate,
The physical strength of the coating film is not required as much as with conventional coating materials or paints. When the water-swellable resin does not have a film-forming ability or a sticking ability or is low,
Or if you want to control the performance after contact with water,
It is preferable to use a synthetic resin or a rubber-like substance as described above in combination.

Further, in the case of a coating material or paint, the suitability for coating such as the adjustment of viscosity can be improved by using the above-mentioned synthetic resin or a rubber-like substance together. The water-swelling resin is obtained as a coating material in advance during synthesis, or the water-swelling resin is used together with a medium such as a synthetic resin, a rubber-like substance, an additive and an organic solvent in a homogenizer, a high speed mixer, a ball mill, a mixing roll, a kneader, and a kneader. Dissolution or dispersion is performed by using a known device used in the production of coating materials, paints, etc., such as an extruder.

The coating material or paint used for producing the water level indicator of the present invention includes a solution or dispersion liquid type using a solvent and a solid type, and a water-swellable resin is also a liquid, a solvent dissolving type, a solvent fine dispersion type,
There are various types such as powder type, and there are various methods such as applying a coating material or paint to volatilize and dry the solvent, hot melt, or stick with an adhesive. Then, the rigid base material is selected.

When other substances are used in combination with the water-swellable resin, particularly when a synthetic resin or a rubber-like substance is used, the content of the water-swellable resin is 100 to 10% by weight, preferably 100 to 30% by weight.
Is. These also vary depending on the performance required for the water level indicator and the materials used, especially the properties of the water-swellable resin.

(Effect) Since the water level indicator obtained by the present invention is a water-swellable resin to which a rigid base is added together with a rubber-like substance, a coloring agent, etc., if necessary, it is necessary easily and inexpensively. The amount can be supplied at any time, and when it comes into contact with water, it causes an irreversible state such as peeling or falling due to swelling, and the maximum water level reached in the past can be easily confirmed at any time.

In addition, the material and shape of the base material can be arbitrarily set and created, and it can be installed at any place or on an object, for example, rivers, lakes, groundwater, agricultural water, sewers, drains, etc. It can be effectively used for grasping the water depth, water level, etc., and for grasping the inundation status of warehouses, unmanned structures, etc.

(Example) Next, an Example is given and this invention is demonstrated still more concretely.
In the text, parts and% are based on weight.

Example 1 Thioglycolic acid was added to 90% of the double bonds of a block copolymer (polystyrene content of 30%) having a (polystyrene)-(polybutanediene)-(polystyrene) bond form and neutralized with caustic soda. Then, a water-swellable resin (swelling degree about 50 times) was prepared.

400 parts of 80 parts of the water-swellable resin dispersed in a toluene-cyclohexane-dioxane mixed solvent, 100 parts of a toluene solution of butyl rubber (solid content 20%) and 5 parts of a blue oil-soluble dye (phthalocyanine solvent blue) A blue coating composition was made by stirring and mixing using a homogenizer.

Separately, a screen was prepared so that the coated portion of 3 mm and the uncoated portion of 2 mm became a horizontal pattern. Length 1m,
The blue coating composition was screen-coated on the acrylic plate having a width of 30 cm and a thickness of 3 mm by using the above screen. After preliminary drying at 50 ° C, it was dried at 130 ° C for 30 minutes.

As shown in FIG. 1a, the colored acrylic plate was cut into a thin rod shape having a width of 2 cm and a length of 1 m so that the striped pattern 2 was in the lateral direction, to obtain a water level indicator 1 of the present invention.

This was set in water at a water level of 3 as shown in FIG. 1b.
After about 20 minutes, the colored pattern part 2 below the water surface swells and extends in the lateral direction, and after another 10 to 20 minutes, the colored pattern part 2
Was peeled from the acrylic plate surface.

When the water level indicator 1 soaked in water is pulled up, the colored pattern portion 2 below the water surface 3 has fallen off, and since the pattern portion 2 on the water surface remains, The position was clearly confirmed. In this way, the maximum water level of rivers, lakes, water for agriculture, etc. can be measured.

Similarly, a water level indicator of the present invention was obtained using a hard vinyl chloride resin plate. Also, 5m for polypropylene rod
The water level indicator of the present invention was similarly obtained by applying a pattern of 5 mm every m.

Example 2 Polyethylene glycol (PEG) -tolylene diisocyanate (TDI) -polybutanediene (PB) bonded water-swellable resin (ratio PEG / TDI / PB 82/15/3 by weight, degree of swelling approx. 90 parts, acrylic rubber 10 parts, and red azo pigment (CI Pigment Red 112) 5 parts were dissolved and dispersed in 300 parts of a mixed solvent of butyl acetate and butanol 60/40 to prepare a red coating liquid.

The same screen used in Example 1 was used to screen coat onto a polyester film 1 m long and 30 cm wide. After preliminary drying at 50 ° C, it was dried at 130 ° C for 30 minutes.

Then, the blue polyester film was cut into a thin ribbon having a width of 2 cm and a length of 1 m so that the pattern was in the horizontal direction, and a double-sided adhesive tape was attached to the back surface to give a colored piece. Stick these colored pieces on a plastic rod at regular intervals,
It was set in water in the same manner as in Example 1. After about 30 minutes, the colored film-like portion below the water surface swelled, and after about 30 minutes, the colored coating film peeled off from the polyester film. When the water level indicator submerged in water was pulled up, the colored film below the water surface fell off, and the pattern on the water surface remained, so the position of the water contact area was clearly confirmed. .

Also, the above-mentioned colored pieces can be attached to the grain bags stored in the grain warehouse to take measures for identifying the contamination at the time of flood such as flood.

Instead of the water-swellable resin of Examples 1 and 2, a water-swellable resin (swelling degree about 400 times) obtained by crosslinking a mixture of acrylic acid and sodium acrylate, polyvinyl alcohol (saponification degree 88%). ), Gelatin powder, starch powder, agar powder, polyethylene glycol-polypropylene glycol-polyethylene glycol (polyethylene glycol 80%), polyethylene glycol disteanate and polyethylene glycol nonylphenyl ether are used in the same manner as in Example 1 according to the present invention. I was able to make a water level indicator.

[Brief description of drawings]

 FIG. 1 is a diagram for explaining the water level indicator of the present invention. 1: Water level indicator 2: Colored pattern 3: Water level 4: Ground

 ─────────────────────────────────────────────────── ─── Continuation of the front page (56) Reference JP-A-59-231418 (JP, A) Actually opened 61-63106 (JP, U) Actually opened 59-23630 (JP, U)

Claims (2)

[Claims] 1. A colored substance containing a water-swellable resin, which peels, falls off or disintegrates upon contact with water, is applied to a vertically long rigid base material in horizontal stripes at regular intervals, fused or adhered. A water level indicator for confirming the water level in the water area. 2. A water-swellable resin (hydrophobic segment)-
The water level indicator according to claim (1), which is a block copolymer or a graft copolymer having a (hydrophilic segment)-(hydrophobic segment) bonding form.