JPS61246281A - Method of preventing deposition of scale on drainage pipe of toilet - Google Patents

Abstract

PURPOSE:To easily prevent the deposition of scale on the inside of a drainage pipe for toilet, by adjusting the pH of urine or a mixture of urine with washing water to a specific value. CONSTITUTION:The pH value of urine or its mixture with washing water is adjusted at 5-8.5. The pH of urine or its mixture is adjusted by adding an acidic substance to the urine and/or washing water. The acidic substance to be used should meet the requirements that when it is added to the urine or its mixture it forms no salt having a solubility in water of less than 0.01g per 100g of water having a pH of 5-8.5 as a result of reaction with calcium and that it can adjust the pH of the urine or its mixture at 5-8.5.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a method for preventing scaling of toilet drain pipes.
More specifically, the present invention relates to a method for preventing scale, which is mainly composed of calcium, from adhering to a toilet drain pipe.

The method of the present invention can be applied to any type of flush toilet or men's toilet without flush facilities.

[Conventional technology]

In toilet drain pipes, especially those in men's restrooms, scale called urinary stone, which is a mixture of calcium-based compounds and pollutants produced by the decomposition of urine, forms, causing urine and wash water to become clogged. This worsens the flow and, in severe cases, blocks the drain pipes, rendering the toilet unusable.

Furthermore, organic matter in urinary stones is decomposed by bacteria and produces a foul odor. The foul odor in the men's restroom is a mixture of foul odor from decaying organic matter and ammonia produced by the decomposition of urine.

BACKGROUND ART Conventionally, methods for preventing scale in toilet drain pipes have been put into practical use, such as a method in which a chemical is injected into the middle of a flush water pipe, and a method in which a chemical formed into a spherical shape is poured into a toilet bowl in a men's restroom.

Various drugs containing surfactants, bactericides, and fragrances have been proposed for use in these methods.

For example, Japanese Patent Publication No. 30706/1989 describes a deodorizing cleaning agent for flush toilets made by melt-mixing a surfactant, an ion sequestrant, a fragrance, etc. with polyethylene glycol or polypropylene glycol and an aromatic substance, and then injection molding the mixture. has been done. In addition, an automatic cleaning agent for flush toilets based on ethylene oxide/propylene oxide copolymer, which is a nonionic surfactant, was developed under the Japanese Patent Publication No. 50-1720.
It is described in Publication No. 5.

Furthermore, as methods for removing scale that has once stuck to the toilet drain pipe, methods have been adopted, such as using a strong inorganic acid such as hydrochloric acid to dissolve the scale, and removing the toilet bowl and mechanically removing the scale.

[Problem that the invention seeks to solve]

The use of conventional agents consisting of surfactants, disinfectants, and fragrances is effective in preventing soiling of toilet bowl walls and preventing the generation of bad odors. However, the effect of preventing scale from adhering to the toilet drain pipe is not sufficient, and the flow of disinfectant into the septic tank interferes with the action of the septic seed bacteria, reducing the purification ability of the septic tank.

The use of cleaning and deodorizing agents consisting of surfactants and fragrances is also effective in preventing stains on the toilet bowl wall and in preventing the generation of bad odors.

However, the effect of preventing scale from sticking to toilet drain pipes is even smaller.

Adding an ion sequestering agent to urine or wash water is quite effective in preventing scale build-up.

However, to completely prevent scale from sticking,
It is necessary to add 0.3 to 1% by weight of ion sequestrant to urine. Generally, ion sequestering agents are expensive and this method is difficult to widely popularize.

Furthermore, dissolving and removing fixed scale using strong acids and mechanically removing fixed scale by removing the toilet bowl are unpleasant and difficult tasks. In addition, when removing scale using strong acids, corrosion of the drain pipes due to the acid and a decrease in purification ability due to the acid flowing into the septic tank become a problem, while when removing scale mechanically, damage to toilet bowls and drain pipes becomes a problem.

An object of the present invention is to provide a simple and economical method for preventing scale from sticking to toilet drain pipes.

[Means for solving problems]

The present invention reduces the pH of urine or mixed wastewater of urine and washing water to 5.
This is a method for preventing scale in a toilet drain pipe, which is characterized by adjusting the scale to 8.5.

In the present invention, the p of urine or mixed wastewater of urine and washing water is
H adjustment is performed by adding an acidic substance to urine and/or wash water.

As the acidic substance, when added to urine or mixed wastewater of urine and washing water, a salt with a solubility in water of pH 5 to 8.5 of 0.01 g/100 g (water) or less reacts with calcium ions. It is possible to use a substance that does not generate water and can adjust the pH of urine or mixed waste water of urine and washing water to a range of 5 to 8.5. For example, mineral acids such as hydrochloric acid, sulfuric acid, and nitric acid; organic acids such as acetic acid, hydroxyacetic acid, succinic acid, benzoic acid, and citric acid; water-soluble acid salts such as sodium hydrogen sulfate, potassium hydrogen sulfate, and ammonium hydrogen sulfate; and ammonium chloride. , water-soluble salts of strong acids and weak bases such as ammonium sulfate, and sulfamic acid. These acidic substances can be used alone or as a mixture of two or more.

As a method and device for adding and dissolving acidic substances into urine and/or wash water and adjusting the pH thereof, known methods and devices conventionally used for adding various drugs to toilets can be used. can. for example,
A method in which an automatic injection device for an aqueous solution of an acidic substance is installed in the flushing water tank of a toilet or in the middle of the flushing water pipe, and a fixed amount of an aqueous solution of an acidic substance is injected into the flushing water each time the flushing water flows out. A method in which a molded body containing an acidic substance that is solid at room temperature is housed in a container, placed in a wash water tank or a wash water flow channel, and brought into contact with the wash water to dissolve the acidic substance; A method can be adopted in which the acidic substance is dissolved by placing it in the toilet bowl of the men's restroom and bringing it into direct contact with urine or washing water. A more specific method will be explained below.

It was proposed in Utility Model Application Publication No. 53-124266, etc., and
An aqueous solution of an acidic substance is filled with a device that injects a certain amount of a liquid substance into the cleaning water tank using the upper and lower water levels of various types of cleaning water tanks that have been put into practical use.The device is then installed in the cleaning water tank. Each time the wash water flows out, a certain amount of an aqueous solution of an acidic substance is injected into the wash water, and the pH of the mixed wastewater of urine and wash water is adjusted to a certain range.

Utility Model Application Publication No. 1984-125840, Utility Model Application Publication No. 53-134
It is also possible to use a device that is proposed in Japanese Patent No. 540 and has been put into practical use and is connected to the middle of the washing water piping and automatically injects a certain amount of liquid chemical into the washing water each time the washing water flows out. In this case, even in toilets that are not equipped with a flush water tank, the pH of the mixed wastewater of urine and flush water is
H can be adjusted by dissolving a solid detergent in the wash water in the wash water tank, which has been proposed in Utility Model Application Publications No. 49-133461 and No. 52-130462, and has also been put into practical use. A molded body containing a solid acid, etc. as an acidic substance is placed in a container for washing, and the solid acid, etc. is dissolved in the washing water by placing it in a washing water tank and adjusting the pH of the mixed wastewater of urine and washing water. Can be adjusted.

There is also a method in which a molded article containing a solid acid, etc. as an acidic substance is placed in a container, brought into contact with water from a faucet for hand washing, and the water in which the solid acid, etc. is dissolved is stored in a washing water low tank. -143038 Publication, Utility Model Publication No. 1621/1989
(Refer to Publication No. 54, etc.) and a method in which a container containing a molded body containing a solid acid or the like as an acidic substance is placed in the flushing water channel in the toilet bowl and the solid acid, etc. is dissolved in the flushing water (Utility Model No. 5).
0-11347, Utility Model Application Publication No. 51-115737, etc.), the pH of the mixed wastewater of urine and washing water is determined.
can also be adjusted.

In the method using an aqueous solution of an acidic substance, the pHf of the mixed wastewater of urine and washing water is adjusted by selecting the concentration and injection amount of the aqueous solution.

If desired, surfactants, fragrances, colorants, corrosion inhibitors, etc. may be added to the aqueous solution of the acidic substance. Furthermore, it is also possible to add a type of fungicide that does not affect the purification seed bacteria or an amount that has a negligible effect, and an ion sequestering agent that does not cause an economic burden.

Molded objects containing acidic substances that are solid at room temperature, such as solid acids,
It is a molded article consisting of an acidic substance, a base material, and optionally added additives. Examples of additives include dissolution rate regulators, surfactants, fragrances, colorants, corrosion inhibitors, bactericides, ion sequestering agents, and the like.

Among the acidic substances mentioned above, various salts, organic acids, and sulfamic acid are used as the acidic substances that are solid at room temperature.

As the base material, sublimable substances such as balajichlorobenzene, naphthalene, etc., water-soluble polymers that are solid at room temperature, such as polyethylene glycol, polypropylene glycol, various surfactants, etc. are used.

These molded bodies can be produced using known methods such as mixing powder and/or granular components and compressing them into tablets, heating a mixture of the components, and injecting a molten slurry into a mold to cool and solidify. It can be manufactured by a molding method.

Fine powder of ta aqueous material can be used as a dissolution rate regulator. For example, calcium stearate, magnesium stearate, etc. are preferably used.

By adjusting the dissolution rate, shape, number of molded bodies, etc. used, the pH of urine or mixed wastewater of urine and washing water can be adjusted at tJ4.
can be adjusted.

The dissolution rate of the molded article can be adjusted by selecting the type and quantitative ratio of the acidic substance used, the base material, etc., and by using a dissolution rate regulator.

In particular, in the case of molded products that are placed directly into men's restrooms, it is required that the dissolution rate is appropriate and that they do not undergo significant deformation such as disintegration or swelling upon contact with urine and/or washing water. .

As molded bodies for these uses, a mixture of an acidic substance powder that is solid at room temperature and a fine powder of baladichlorobenzene is compressed into a molded body and a mixed melt of baladichlorobenzene and a water-soluble polymer. A molded body obtained by injecting a slurry in which a powder of an acidic substance is added and mixed into a desired mold and cooling and solidifying is preferably used.

[For production]

As a result of intensive research into methods for preventing scale from adhering to toilet drain pipes, the present inventors found that the scale was composed of calcium apatite (Cas(POe)sOH) 40-6
0 i+t%, calcium carbonate (CaCOs) 2
0-40 ht% and water-insoluble organic matter 10-30-
t% mixture, calcium scale is p
Precipitation does not occur in water with H of 7.5 or less, and in water with a pH of 7.5 to 8.
In water in the range of 5, even if it precipitates, it is extremely small, and it takes a long time to precipitate. Also, urine or mixed wastewater of urine and washing water produces ammonia due to the action of urine degrading enzymes, and the precipitation is short. They discovered that pH increases with time and completed the present invention.

Urine usually contains 200 to 3 water-soluble calcium ions.
00pp+m, phosphate ion is 2000~2500
ppn+ included. Further, carbonate ions are contained in the washing water, and are replenished by dissolving carbon dioxide gas in the atmosphere. The pH of urine excreted from the body is about 6-6.5, but when left in the atmosphere, the pH gradually increases and eventually reaches 9-9.5. When the pH exceeds 7.5, turbidity occurs, and as the po increases, the turbidity increases until the pH reaches 8.
When the value exceeds 5, a white precipitate of calcium apatite is deposited, and a film of calcium carbonate crystals is formed on the surface in contact with the atmosphere. These calcium apatite and calcium carbonate crystals, together with water-insoluble proteins and other organic matter produced by the action of bacteria and enzymes, stick to the toilet drain pipe and grow into scale, commonly called urinary stones.

Therefore, by maintaining the pH of urine or mixed wastewater of urine and wash water at 8.5 or less, preferably 7.5 or less, it is possible to prevent scale from adhering to the toilet drain pipe. As a method for maintaining the pH of urine or mixed waste water of urine and washing water at 8.5 or less, a method of dissolving an acidic substance in urine and/or washing water is simple and preferably adopted.

Toilets may not be used for long periods of time on holidays, etc., so in order to maintain the PLL of urine or mixed wastewater of urine and wash water that remains in the drain pipes even during such periods, the PLL should be kept at 8.5 or less. As an acidic substance, its ammonium salt increases the pH
Those having strong acid groups exhibiting buffering properties are preferably used. However, it is not preferable to use an acidic substance whose solubility in water of the salt produced by reaction with calcium is less than 0, 1 g/100 g (water).

On the other hand, if the pH of urine or the mixed waste water of urine and washing water is too low, it is undesirable because corrosion of the drain pipe becomes a problem.
Therefore, pll of urine or mixed waste water with urine and wash water
A preferable lower limit of is 5, more preferably 5.5.

〔Example〕

The present invention will be explained in more detail by way of examples.

However, the scope of the present invention is not limited to the same extent by the following examples.

Example 1 Fresh urine 34! (pH-6,35) was collected and divided into 6 equal parts, each containing 500 sJ! The sample was subjected to the following treatment, and the change in pll and the amount of water-insoluble matter produced were measured.

Each sample was kept at 20 ± 3°C during the measurement period.

Sample 1: Add sulfamic acid and adjust the pH to 5.5 Sample 2: Continuously inject 1% sulfamic acid aqueous solution to adjust the pH to 7.2 ± 0.2 Sample 3: From the automatic titrator , 1% sulfamic acid aqueous solution was continuously injected to adjust the pH to 8.2 ± 0.2 Sample 4: 1% sulfamine from an automatic titrator (comparison)
Continuously inject acid aqueous solution to adjust pH to 8.8 ± 0.2 Sample 5: Added disinfectant; benzalkonium chloride 0.5 g (comparison) Sample 6: Untreated (comparison) Depending on the elapsed time of each sample Changes in pH and the amount of water-insoluble matter produced (g/j) are shown in Table 1.

Table 1 Example 2 Three men's urinals are regularly flushed once an hour with flush water from a 10 ffi flush water tank. Each urinal in five toilets is treated with anti-corrosion agent. The sample was washed with hydrochloric acid, and scale adhesion prevention treatment was performed using the following method.

Specification l: 0.6111j every time the cleaning water flows out! In a commercially available chemical supply container designed to supply a liquid chemical to a cleaning water tank, a chemical containing 35% hydrochloric acid and 1% of a corrosion inhibitor (Ivit, manufactured by Asahi Chemical) containing a cationic surfactant as an ingredient was added. was placed in the washing water tank, and the chemical was periodically supplied into the washing water.

Specification 2: A mixture consisting of sulfamic acid powder; 60 parts by weight Paradichlorobenzene fine powder; 40 parts by weight and calcium stearate; 2 parts by weight was pressure-molded and three spherical molded bodies with a diameter of 40 as were placed in a urinal. and dissolved in urine and wash water.

Specification 3: Same specifications as the drug supply container used in Specification 1 (comparison)
disinfectant benzalkonium chloride;
It was filled with an aqueous solution containing 20% and 10% of ethylene oxide-propylene oxide copolymer (nonionic surfactant), and placed in the washing water tank, and the chemical was periodically supplied into the washing water.

Specification 4: Ethylene oxide-pro which is solid at room temperature (comparison)
Pyrene oxide copolymer (nonionic surfactant)
After heating and melting the mixture and injecting it into a mold, one spherical molded body with a diameter of 40 mm produced by cooling and solidifying was placed in a urinal and dissolved in urine and washing water.

Specification 5 Ni blank.

(Comparison) A cylindrical test piece made of stainless steel wire mesh and a 20-x 70m+m x 1mm iron piece were installed in the trap section under the perforated plate of each toilet bowl, and the amount of scale adhering to the wire mesh and the amount of corrosion on the iron piece was measured. did.

In addition, the pH of the mixed wastewater of urine and washing water in the trap, and the pH of the septic tank water before using the drug and one week after starting the use of the drug.
o and COD were measured.

To eliminate errors due to the frequency of toilet use, the test piece, iron piece, and drug were changed every three weeks, and tests were conducted in all five toilets for three weeks each.

For Specifications 1 and 3, drugs were replenished every 3 weeks. In treatments m2 and 4, a new drug was added when the weight of the drug became 20% or less of the initial value.

The results of each measurement are shown in Table 2.

In Table 2, each symbol represents the following.

Toilet wall stains: ◎; No stains ○; Almost no stains Δ; Some stains ×; Dirt and bad odor: ◎; No bad odor 0; Almost no bad odor △; Slightly bad odor ×; Bad odor 2nd Table [Effects of the Invention] In the present invention, as shown in Example 1 above, the pH of urine
(If the pH is below 8.5, very little precipitate will be formed, and if the pH is below 7.5, no precipitate will be formed at all. Therefore, the pH of urine or mixed wastewater of urine and washing water By adjusting and maintaining the ratio to 8.5 or less, preferably 7.5 or less, it is possible to prevent scale from sticking to the toilet drain pipe.

This is even clearer in the specific example of a urinal in a men's restroom shown in Example 2.

Further, in the method of the present invention, corrosion of the drain pipe is extremely small and does not adversely affect the function of the septic tank.

In the example, a specific example of a men's restroom with a cleaning device was shown, but a men's restroom without a cleaning device,
Similar results can be obtained in unisex toilets with cleaning equipment.

The present invention provides a simple method for preventing scale buildup in toilet drain pipes, and has extremely great public health and industrial significance.

Claims (6)

[Claims] (1) Adjust the pH of urine or mixed wastewater of urine and washing water to 5 to 8.
．． A method for preventing scale in a toilet drain pipe, characterized by adjusting the scale to 5. (2) pH adjustment of urine or mixed wastewater of urine and washing water,
A method for preventing scale in a toilet drain pipe according to claim 1, which is carried out by adding an acidic substance to urine and/or washing water. (3) The method for preventing scaling of toilet drain pipes according to claim 2, wherein the acidic substance is mineral acids, organic acids, water-soluble acid salts, water-soluble salts of strong acids and weak bases, and/or sulfamic acid. (4) A claim in which an automatic injection device for an aqueous solution of an acidic substance is installed in a flushing water tank of a toilet or in the middle of a flushing water pipe, and an aqueous solution of an acidic substance is injected into the flushing water every time the flushing water flows out. Method for preventing scaling of toilet drain pipes as described in item 1 or 2 (5) A method for preventing scale in a toilet drain pipe according to claim 1 or 2, which comprises placing a molded product containing a solid acid as an active ingredient in a container and installing it in a wash water tank or a wash water flow channel. (6) A method for preventing scaling of a toilet drain pipe according to claim 1 or 2, which comprises disposing a molded article containing a solid acid as an active ingredient in a men's toilet bowl.