JP7819002B2 - Detergents and descaling methods - Google Patents

Description

The present invention relates to a cleaning agent used to remove limescale and a method for removing limescale.

The limescale that forms on sinks, electric kettles, etc. is caused by mineral components such as calcium carbonate and magnesium contained in tap water. It is known that if water that splashes during cooking or washing dishes is left alone, the water evaporates, leaving behind the mineral components that form limescale.

A known method for removing limescale caused by mineral components is to dissolve the main components, such as calcium carbonate and magnesium, using acid. For example, Patent Document 1 proposes a cleaning agent whose main ingredients are citric acid and ascorbic acid.

Japanese Patent Application Publication No. 7-252498

The cleaning agent described in Patent Document 1 removes limescale primarily through the action of citric acid, but when limescale is removed using citric acid, calcium citrate, which has extremely low solubility in water, precipitates and adheres to sinks, electric kettles, and other surfaces as stains, creating a problem.

In addition, limescale frequently forms on sinks, electric kettles, etc., and requires regular removal using detergent, but frequent use of detergents containing citric acid can cause the problem of rough hands.

The present invention was developed in consideration of the above-mentioned circumstances, and its objective is to provide a detergent that exhibits excellent limescale removal effects while suppressing calcium salt precipitation and rough hands during use, as well as a method of removing limescale using this detergent.

As a result of extensive research into the various functions of 3-hydroxybutyric acid, the inventors of the present application experimentally demonstrated that 3-hydroxybutyric acid is effective in removing limescale, leading to the completion of the present invention.

That is, the cleaning agent according to the present invention for achieving the above object is characterized by the following features:
It contains 3-hydroxybutyric acid as a main component and is in solid form .

According to the above characteristic configuration, 3-hydroxybutyric acid can dissolve and remove mineral components contained in limescale, etc., thereby providing excellent limescale removal effects. Furthermore, since 3-hydroxybutyric acid has a high solubility in water as its calcium salt and is less irritating to the skin, a cleanser having the above characteristic configuration is less likely to cause calcium salt precipitation and less likely to cause rough hands. Furthermore, according to the above characteristic configuration, it is easy to store.
A further characteristic feature of the cleaning agent according to the present invention is that it contains 3-hydroxybutyric acid as a main component and is a limescale remover.
According to the above characteristic configuration, a scale remover that exhibits excellent scale removal effect due to 3-hydroxybutyric acid can be realized.

Further characteristic features of the cleaning agent according to the present invention are:
The solution contains at least the 3-hydroxybutyric acid and water.

With the above-mentioned features, the cleaning agent is in the form of a solution, so it can be used in a relatively simple manner, such as by applying or spraying it onto areas where limescale or other issues have formed. Furthermore, because the solvent is non-toxic and harmless, and water is less expensive than other organic solvents, increases in manufacturing costs can be suppressed, and hand irritation caused by the solvent can also be reduced.

Further characteristic features of the cleaning agent according to the present invention are:
The concentration of the 3-hydroxybutyric acid is 1 w/v % or more.

The above characteristic configuration allows 3-hydroxybutyric acid to fully remove limescale and other impurities.

Further characteristic features of the cleaning agent according to the present invention are:
The conformation of the 3-hydroxybutyric acid is R-configuration.

The inventors of this application have experimentally confirmed that cleaning solutions containing R-3-hydroxybutyric acid are effective in removing limescale and other impurities.

Further characteristic features of the cleaning agent according to the present invention are:
Furthermore, it contains additives.

With the above-mentioned features, the cleaning agent contains various additives, which not only removes limescale and other impurities, but also provides various other effects depending on the function of the additives.

Further characteristic features of the cleaning agent according to the present invention are:
It is a limescale remover.

The above characteristic features make it possible to create a limescale remover that exhibits excellent limescale removal effects due to 3-hydroxybutyric acid.

The characteristic configuration of the limescale removal method according to the present invention to achieve the above object is as follows:
The detergent is used to dissolve mineral components contained in limescale, thereby removing the limescale.

The above-mentioned features and configurations make it possible to remove limescale while preventing calcium salt deposition and rough hands during use.

1 is a graph showing the results of a solubility test of calcium carbonate. 1 is a graph showing the results of a solubility test of calcium carbonate. 1 is a graph showing the results of a precipitation test. 1 is a photograph showing the results of a solubility test of calcium salts. 1 is a photograph showing the results of a solubility test of calcium salts.

The cleaning agent and limescale removal method according to the present invention will be described below. Note that while preferred examples are provided below to more specifically illustrate the present invention, various modifications are possible without departing from the spirit of the present invention, and the present invention is not limited to the following descriptions.

In this specification, "limescale" refers to alkaline dirt caused primarily by mineral components such as calcium carbonate and magnesium.

The cleaning agent of the present invention contains 3-hydroxybutyric acid (3HB) as its main ingredient.

[3HB]
3HB can be obtained, for example, by carrying out a fermentation process in which 3HB-producing Halomonas bacteria are added, followed by separating and removing the Halomonas bacteria from the resulting fermentation broth and purifying it. The fermentation process can be carried out by adding 3HB-producing Halomonas bacteria directly to a raw material solution containing a carbohydrate nutrient source such as fruit juice, followed by aerobic fermentation and microaerobic fermentation (see JP 2013-081403 A). This converts the carbohydrates to 3HB, which is then produced in the fermentation broth. The produced 3HB is then separated and purified by membrane separation or other conventional methods and used as pure 3HB. In this case, the resulting 3HB is the R-isomer.

The 3HB contained in the cleaning agent of the present invention is not limited to that derived from microorganisms as described above, but may also be obtained by organic synthesis. Furthermore, there are no particular limitations on the conformation, and it may be either the R- or S-configuration.

[Cleaning agent]
The detergent contains the above-mentioned 3HB as its main ingredient, and the 3HB can dissolve and remove mineral components contained in limescale, etc., thereby exhibiting excellent limescale removal effects. Therefore, it is particularly useful as a limescale remover and can be used in limescale removal methods that dissolve mineral components contained in limescale. Furthermore, the calcium salt of the main ingredient, 3HB, has high solubility in water, making it less irritating to the skin. Therefore, compared to detergents containing citric acid or other ingredients as their main ingredients, the detergent is less likely to precipitate calcium salts and less likely to cause rough hands.

The detergent may be in liquid or solid form. Furthermore, as long as the detergent contains 3HB as one of the functional ingredients that contributes to limescale removal, it may also contain various additives as needed.

Additives include, but are not limited to, surfactants, moisturizing ingredients, thickeners, solvents, fragrances, antibacterial agents, antioxidants, chelating agents, pH adjusters, etc.

When the cleaner is in liquid form, it can be used in a relatively simple way, such as by applying or spraying it onto areas where limescale or other problems have formed. It is preferable to use water as the solvent. Cleaners (cleaning solutions) that use water as the solvent can reduce manufacturing costs and prevent hand irritation caused by the solvent, as the water solvent is non-toxic, harmless, and relatively inexpensive.

Furthermore, when the detergent is in liquid form, the concentration of 3HB is preferably 1 w/v% (mass volume percent) or more, more preferably 1 w/v% to 20 w/v% or less, even more preferably 1 w/v% to 10 w/v% or less, and even more preferably 1 w/v% to 5 w/v% or less. If the 3HB concentration is within the above range, the amount of 3HB used can be reduced, and the necessary and sufficient limescale removal effect of 3HB can be obtained without increasing costs.

When the detergent is in a solid form, examples include a powder containing 3HB and a tablet made from this powder. Having a solid detergent has the advantage of being easy to store.

As long as the powder contains 3HB, there are no particular restrictions on the presence or amount of other additives. For example, when the powder is to be subjected to tableting, it may contain appropriate amounts of additives such as excipients and binders, taking into consideration factors such as compression moldability. The amount of 3HB contained in the powder may also be determined appropriately depending on the manner in which the detergent will be used.

Solid detergents can be used, for example, by adding 3HB to water stored in an electric kettle so that the 3HB concentration is approximately 1 w/v% or more. Even in this case, from the perspective of minimizing the amount of 3HB used and achieving the necessary and sufficient limescale removal effect of 3HB without increasing costs, the 3HB concentration is preferably 1 w/v% to 20 w/v%, more preferably 1 w/v% to 10 w/v%, and even more preferably 1 w/v% to 5 w/v%.

[Experimental Example]
The present invention will be described in more detail below based on experimental examples, although it goes without saying that the present invention is not limited to these examples.

[Calcium carbonate solubility test]
Calcium carbonate was used as a simulated limescale, and the solubility of calcium carbonate in aqueous solutions of 3-hydroxybutyric acid, acetic acid, and citric acid was examined.

Specifically, in the solubility test, 5 w/v% aqueous solutions of R-3-hydroxybutyric acid (synthesized by Osaka Gas Co., Ltd.), acetic acid (Kanto Chemical Co., Ltd.), and citric acid (Kishida Chemical Co., Ltd.) were prepared, and approximately 80 mg of calcium carbonate (Hayashi Pure Chemical Industries, Ltd.) was added to 200 μl of each solution, mixed, and then allowed to stand at room temperature for approximately 5 minutes. The solution was then filtered, and the solubility was calculated based on the difference in weight between the added calcium carbonate and the weight of the undissolved calcium carbonate recovered by filtration.

Figure 1 is a graph summarizing the results of the solubility test. As can be seen from the figure, when comparing the solubility of calcium carbonate in a 3HB aqueous solution with that in an acetic acid aqueous solution or a citric acid aqueous solution (0.013 g/mL for the acetic acid aqueous solution, 0.0105 g/mL for the citric acid aqueous solution), the solubility in the 3HB aqueous solution is 0.018 g/mL, meaning that the solubility of calcium carbonate in the 3HB aqueous solution is higher than that in the acetic acid aqueous solution or the citric acid aqueous solution. This shows that 3HB dissolves calcium carbonate, which causes limescale, more easily than acetic acid or citric acid, and that detergents containing 3HB are equally effective at removing limescale as detergents containing acetic acid or citric acid.

We also examined the solubility of calcium carbonate at different concentrations of the above-mentioned 3HB.

Specifically, aqueous solutions of 3HB with different concentrations (0.5 w/v%, 1 w/v%, 2.5 w/v%, 5 w/v%, 10 w/v%, 20 w/v%, 40 w/v%) were prepared, and the solubility was calculated using the same procedure as above. Figure 2 is a graph summarizing the results.

As can be seen from Figure 2, calcium carbonate dissolves when the 3HB concentration is 1 w/v% or higher. Furthermore, solubility tends to increase as the concentration increases, but it reaches a maximum at around 20 w/v% and does not change significantly with increasing concentrations thereafter. This indicates that a 3HB concentration of 20 w/v% or less is preferable from a cost-effective perspective. Furthermore, commercially available limescale removers containing citric acid as the active ingredient have citric acid concentrations of around 2-5 w/v%. The results shown in Figures 1 and 2 indicate that even if the citric acid concentration of commercially available products is assumed to be 5 w/v%, a 3HB aqueous solution concentration of around 2.5 w/v% would be sufficient to achieve the same limescale removal effect (in other words, the same level of solubility).

[Precipitation test]
20 mg of calcium carbonate was added to 1 ml each of the 5 w/v % 3HB aqueous solution and the citric acid aqueous solution prepared in the "Calcium Carbonate Solubility Test" above, mixed, and then allowed to stand at room temperature for 24 hours. Thereafter, a white precipitate was recovered by filtration, and its weight was measured.

Figure 3 is a graph summarizing the results of the precipitation test. Figures 4 and 5 are photographs of the state of each sample during the precipitation test, with Figure 4 taken immediately after mixing and Figure 5 taken 17 hours after mixing. As shown in Figure 3, the 3HB aqueous solution produced significantly less precipitate than the citric acid aqueous solution. Also, as can be seen from Figures 4 and 5, both aqueous solutions were nearly transparent immediately after mixing, but with the citric acid aqueous solution, white precipitates had solidified throughout the container after 17 hours. This confirms that when citric acid is used to remove calcium carbonate and other substances, calcium citrate precipitates even after the calcium carbonate is removed, whereas when 3HB is used, calcium salt precipitation is virtually nonexistent.

[Calcium salt solubility test]
Calcium 3HB (manufactured by Osaka Gas Co., Ltd.) and calcium citrate (manufactured by Kishida Chemical Co., Ltd.) were added to water at room temperature to give concentrations of 0.5 mg/ml, 1 mg/ml, 3 mg/ml, 10 mg/ml, and 100 mg/ml, and the degree of residual dissolution was observed. Complete dissolution was marked as "○", and residual dissolution was marked as "×".

As shown in Table 1, 3HB calcium has extremely high solubility in water compared to calcium citrate. For this reason, detergents containing 3HB can suppress the precipitation of calcium salts when removing limescale compared to detergents containing citric acid.

The cleaning agent and scale removal method of the present invention can be used to remove scale and other substances.

Claims (8)

A solid cleaning agent containing 3-hydroxybutyric acid as its main ingredient. A cleaning agent containing 3-hydroxybutyric acid as its main ingredient and acting as a limescale remover . 3. The cleaning agent according to claim 2 , which is a solution containing at least 3-hydroxybutyric acid and water. 4. The cleaning agent according to claim 3 , wherein the concentration of the 3-hydroxybutyric acid is 1 w/v % or more. The cleaning agent according to any one of claims 1 to 4, wherein the conformation of the 3-hydroxybutyric acid is the R-configuration. The cleaning agent according to any one of claims 1 to 5 further contains an additive. 2. The cleaning agent according to claim 1, which is a limescale remover. A method for removing limescale using the detergent described in any one of claims 1 to 7 to dissolve the mineral components contained in the limescale and remove the limescale.