JPS60209297A - Dissolving agent of water-insoluble calcium salt - Google Patents

Abstract

PURPOSE:To remove easily and surely a water-insoluble calcium salt by using a composition obtained by adding carbonate to a chelating agent as a calcium salt dissolving agent. CONSTITUTION:A preparation of a clacium dissolving agent which is insoluble in water is obtained by adding a carbonate consisting of soda ash, sodium bicarbonate, an ammonium salt, etc. to a chelating agent consisting of ethylenediaminetetraacetic acid or nitrilotriacetic acid. Said preparation is dissolved into water to obtain an aq. soln., and gypsum, boiler sludge, and the sludge in piping wherein hard water is used are dissolved by said aq. soln. Said aq. soln. can be optionally used with immersion, pouring, injection under pressure, spraying, coating, etc. The pH of said dissolving agent is usually regulated to 5-13, however the agent at 7-9pH is effective when rapid dissolution is carried out.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a water-insoluble calcium salt solubilizer.

When molding metals, plastics, ceramics, etc. using gypsum as a mold, a problem arises in that gypsum peels off from the mold surface and adheres to the product.

In the past, there was no suitable tool to remove this adhered gypsum, so it was removed manually, but since the products often have complex shapes with uneven surfaces, the removal process was extremely complicated and time-consuming. It took time.

In addition, calcium sludge is generated when a hot water boiler is used for a long time or inside piping that uses hard water, but conventionally there was no tool that could easily remove this sludge.

The present invention was devised in view of the above circumstances, and its purpose is to easily and reliably remove calcium salts that are insoluble in water, such as sludge that occurs in gypsum, boilers, and piping that uses hard water. Our goal is to provide solvents that can

In order to achieve this object, the present invention uses a composition in which a carbonate is added to a chelating agent as a dissolving agent.

The present invention will be specifically explained below.

The water-insoluble calcium salt solubilizing agent according to the present invention consists of a formulation in which a carbonate is added to a chelating agent. Although an aqueous solution of a single chelating agent can dissolve some amount of gypsum and sludge in boilers or hard water pipes, the dissolution rate is slow and it is not practical.

In order to solve this problem, the present inventor conducted various experiments and obtained the knowledge that calcium salts can be rapidly removed by creating a formulation in which carbonate is added to an aqueous solution of a chelating agent.

That is, by adding a carbonate to the chelating agent, the dissolution rate of the calcium salt becomes faster, and the effect of the addition of the carbonate causes the calcium salt to dissolve while foaming. Due to the physical effects of this foaming, the calcium salts adhering to products, boilers, and piping become finer, and this finer size increases the contact area between the chelating agent and the aqueous solution containing carbonate, further increasing the dissolution rate. It will be faster.

Here, as a chelating agent, ethylenediaminetetraacetic acid (E, D, T, A) is particularly effective, but other chelating agents such as nitrilotriacetic acid (N, T, A),
Cyclohexanediaminetetraacetic acid (Cy, D, T, 8),
Glycol ether diamine acetic acid (G.[!.D.T.
A), ethyl ether diamine pentaacetic acid ([!.E.
D. T. A), diethylenetriaminepentaacetic acid (D.T.
．． P. ^), dihydroxyethylglycine (D.H.E.
．． G), hydroxyethylethylene thiamine triacetic acid (11.E.D.T.A.), etc. can also be used. Further, as the carbonate, soda ash or bicarbonate of soda can be used.

The preparation prepared by adding carbonate to the above chelating agent is made into an aqueous solution,
This aqueous solution dissolves gypsum, boiler sludge, and sludge in pipes that use hard water. Its usage is dipping,
Pouring, pressure injection, spraying, coating, etc. are optional. It goes without saying that other additives such as stabilizers may be added to the above formulation.

The temperature used may be room temperature, but the rate of calcium salt dissolution becomes faster by heating. Furthermore, adding physical effects such as ultrasonic waves is also an effective auxiliary effect.

It should be noted that the solubilizing agent of the present invention is not particularly limited.

That is, generally p) 15 to 13 is sufficient,
In particular, when dissolving rapidly, a pH of about 7 to 9 is effective. Therefore, there is no particular limitation on the combination of the chelating agent and the carbonate, and the amount may generally be about 5 mol or less of the carbonate per 1 mol of the chelating agent. A particularly effective formulation is 0.3 to 3 moles of carbonate per mole of chelating agent.

Next, examples of the present invention will be shown.

EXAMPLE A dissolving agent was obtained according to the present invention, and 50 days of gypsum was immersed in this dissolving agent, and the time until the gypsum was completely dissolved was measured. The results are shown in Table 1 below along with comparative examples.

As is clear from Table 1, the present invention exhibits superior dissolution characteristics compared to the comparative example.

Patent Applicant Chemicoat Co., Ltd. Procedural Amendment May 21, 1980 1, Case Description Patent Application No. 64135 of 1982 2, Title of Invention Water-insoluble Calcium Salt Solubilizer 3, Person Making Amendment Case Relationship with Patent Applicant Chemicoat Co., Ltd. Detailed Description of the Invention 7, Amendment Contents As shown in the attached sheet, Amendment 1: In the specification of the present application, lines 8 to 9 on page 4 are corrected as follows. .

"Yes. Also, as the carbonate, water-soluble carbonates such as soda ash, sodium bicarbonate, and ammonia salt can be used.

Claims (1)

[Claims] ■ A water-insoluble calcium salt solubilizing agent comprising a preparation containing a chelating agent and a carbonate. 2. The water-insoluble calcium salt dissolving agent according to claim 1, wherein the preparation is used for dissolving gypsum. 3. The water-insoluble calcium salt dissolving agent according to claim 1, wherein the preparation is used for removing sludge generated in boilers and piping that uses hard water.