JP2019210532A - Carbohydrazide-containing composition and method of stabilizing carbohydrazide - Google Patents

Abstract

To provide a carbohydrazide-containing composition that is excellent in the stability of carbohydrazide, and prevents the precipitation of foreign matter even in a state where carbohydrazide is exposed to the atmosphere environment or it is solutionized, and a method of stabilizing carbohydrazide.SOLUTION: A carbohydrazide-containing composition has carbohydrazide, and a material A composed of at least one selected from the group consisting of erythorbic acid, ascorbic acid, sorbic acid and benzoic acid.SELECTED DRAWING: None

Description

  The present invention relates to a carbohydrazide-containing composition and a method for stabilizing carbohydrazide.

  Carbohydrazide is used as an anticorrosive agent for a boiler system, an oxygen scavenger, a crosslinking agent for a synthetic resin, a curing agent, and the like.

  When used as an anticorrosive and oxygen scavenger in boiler systems, it is mainly used as an alternative to hydrazine. Although hydrazine has been used as an oxygen scavenger (anticorrosive) that reacts with dissolved oxygen, it has been recognized as mutagenic and is a substance that falls under Class 1 Designated Chemical Substances (PRTR).

  For this reason, carbohydrazide, which is safer and does not correspond to the first class designated chemical substance (PRTR), has begun to be used as an alternative to hydrazine (see, for example, Patent Document 1).

  However, in a state where carbohydrazide is exposed to the atmospheric environment or in a solution state, there has been a problem that unintentional chemical reaction proceeds in a relatively short period of time and foreign matter is likely to precipitate. If such foreign matter is precipitated, the solubility in the solvent is remarkably inferior, the flow path such as a chemical injection pipe for injecting the carbohydrazide solution is blocked, and the use (boiler anticorrosive agent, oxygen scavenger and synthesis) Such as a crosslinking agent, a curing agent, etc. of the resin).

Japanese Patent Laid-Open No. 57-133506

  An object of the present invention is to provide a carbohydrazide-containing composition that is excellent in stability of carbohydrazide and is less likely to precipitate foreign matter even when the carbohydrazide is exposed to the atmospheric environment or in a solution state. Another object of the present invention is to provide a method for stabilizing carbohydrazide.

Such an object is achieved by the present invention described in the following (1) to (6).
(1) Carbohydrazide,
A carbohydrazide-containing composition comprising: substance A consisting of at least one selected from the group consisting of erythorbic acid, ascorbic acid, sorbic acid and benzoic acid.

  (2) The carbohydrazide-containing composition according to (1), wherein at least a part of the substance A is contained in the carbohydrazide-containing composition in a salt state.

(3) When the content of the carbohydrazide in the carbohydrazide-containing composition is X _C [mass%] and the content of the substance A in the carbohydrazide-containing composition is X _A [mass%], it is 0. The carbohydrazide-containing composition according to (1) or (2), which satisfies a relationship of 0001 ≦ X _A / X _C.

  (4) The carbohydrazide-containing composition according to any one of (1) to (3), wherein the carbohydrazide-containing composition has a function of removing dissolved oxygen contained in the liquid.

  (5) The carbohydrazide-containing composition according to any one of (1) to (4), wherein the carbohydrazide-containing composition is applied to a boiler system.

  (6) A method for stabilizing carbohydrazide, comprising adding a substance A comprising at least one selected from the group consisting of erythorbic acid, ascorbic acid, sorbic acid and benzoic acid to a composition containing carbohydrazide. .

  According to the present invention, it is possible to provide a carbohydrazide-containing composition that is excellent in carbohydrazide stability and is less likely to precipitate foreign matter even when the carbohydrazide is exposed to the atmospheric environment or in a solution state. Moreover, the stabilization method of a carbohydrazide can be provided.

Hereinafter, preferred embodiments of the present invention will be described in detail.
[Carbohydrazide-containing composition]
First, the carbohydrazide-containing composition of the present invention will be described.

  The carbohydrazide-containing composition of the present invention contains carbohydrazide and substance A consisting of at least one selected from the group consisting of erythorbic acid, ascorbic acid, sorbic acid and benzoic acid.

  By such a configuration, it is possible to provide a carbohydrazide-containing composition that is excellent in stability of carbohydrazide and is unlikely to cause precipitation of foreign matters even when the carbohydrazide is exposed to an atmospheric environment or in a solution state. it can. More specifically, by effectively suppressing the precipitation of foreign substances due to unintentional chemical reaction involving carbohydrazide, the use of carbohydrazide (for example, anticorrosive agent for boiler, oxygen scavenger and cross-linking agent for synthetic resin, It is possible to solve problems such as a decrease in the effect for the curing agent.

  In particular, when the carbohydrazide-containing composition has a function of removing dissolved oxygen contained in the liquid (for example, one applied to a boiler system or the like described later), problems such as corrosion are effectively prevented. Can be prevented.

<Carbohydrazide>
The carbohydrazide used in the present invention will be described below.

  Carbohydrazide is used as an anticorrosive agent for boilers, an oxygen scavenger, a crosslinking agent for synthetic resins, a curing agent, and the like. For example, when it is used as an anticorrosive or oxygen scavenger for boilers, it changes to hydrazine in an environment of high temperature and high pressure (for example, temperature: 120 ° C. or higher, pressure: 0.2 MPa or higher). The function to remove effectively is demonstrated.

  Carbohydrazide has a compound represented by the following formula (1). However, in a state where carbohydrazide is exposed to an atmospheric environment or in a solution state, an unintentional chemical reaction occurs in a relatively short period of time. Has progressed and foreign matter tends to precipitate. The foreign matter generated at this time is considered to contain a compound represented by the following formula (2).

In the present invention, carbohydrazide may be present in a salt state at least partially.
Examples of the carbohydrazide salt include salts with the substance A described in detail later.

  The content of carbohydrazide in the carbohydrazide-containing composition (when containing a carbohydrazide salt, the content when converted to carbohydrazide having the chemical structure represented by the above formula (1)) is not particularly limited. However, for example, when the carbohydrazide-containing composition is a liquid composition containing a liquid medium described later, the content is preferably 0.1% by mass or more and 20% by mass or less, and more preferably 0.2% by mass or more and 18% by mass. More preferably, it is 0.5 mass% or less, and further preferably 0.5 mass% or more and 16 mass% or less. Further, for example, when the carbohydrazide-containing composition is a solid composition, the content of carbohydrazide in the carbohydrazide-containing composition (in the case where a carbohydrazide salt is included, the above formula (1) The content ratio in terms of carbohydrazide having the chemical structure shown) is preferably 1% by mass or more and 99.999% by mass or less, more preferably 5% by mass or more and 99.99% by mass or less. More preferably, it is 10 mass% or more and 99.9 mass% or less.

  Thereby, the function which carbohydrazide originally has can be more effectively exhibited, making the stability of the carbohydrazide-containing composition during transportation, storage, etc. more excellent. In addition, for example, even when a carbohydrazide-containing composition is used after being diluted at a relatively high dilution rate, the functions inherent to carbohydrazide can be sufficiently exerted.

<Substance A>
The carbohydrazide-containing composition of the present invention contains at least one substance A selected from the group consisting of erythorbic acid, ascorbic acid, sorbic acid and benzoic acid.

  Substance A suppresses the generation of foreign substances even when the carbohydrazide is exposed to the atmospheric environment or in a solution state, and the activity of carbohydrazide (carbohydrazide inherently possessed by the reaction in which the foreign substances are generated). For example, functions as anticorrosives, oxygen scavengers, crosslinkers, curing agents, etc.). For this reason, by including the substance A together with carbohydrazide, the generation of foreign substances can be suppressed and the activity of carbohydrazide can be maintained excellent over a long period of time.

  In the carbohydrazide-containing composition of the present invention, substance A may be present in the form of a salt at least partially.

  Examples of the salt of the substance A include a salt with the carbohydrazide described above and a salt with a specific amine-based substance described later.

  If the carbohydrazide-containing composition contains a salt of the substance A and carbohydrazide, the activity of carbohydrazide and the effect of inhibiting foreign matter precipitation of carbohydrazide can be achieved at a higher level.

Substance A may be at least one selected from the group consisting of erythorbic acid, ascorbic acid, sorbic acid and benzoic acid (including a salt state), but at least one of erythorbic acid and ascorbic acid (salt) It is preferable that erythorbic acid (including a salt state) is included, and that erythorbic acid (including a salt state) is further included as a main component. preferable.
Thereby, the effects as described above are more remarkably exhibited.

Content ratio of erythorbic acid to the whole substance A contained in the carbohydrazide-containing composition of the present invention (when the substance A contains a salt of the above compound, the content ratio when converted to the compound as an acid that is not a salt) ) Is preferably 50% by mass or more, more preferably 70% by mass or more, and still more preferably 90% by mass or more.
Thereby, the effects as described above are more remarkably exhibited.

  The content of the substance A in the carbohydrazide-containing composition (when the substance A contains a salt of the above compound, the total content when converted to the compound as an acid that is not a salt) is not particularly limited, For example, when the carbohydrazide-containing composition is a liquid composition containing a liquid medium to be described later, it is preferably 0.00001% by mass or more and 20% by mass or less, and 0.0001% by mass or more and 18% by mass. More preferably, it is 0.001 mass% or more and 16 mass% or less.

  Thereby, the stability of the carbohydrazide-containing composition can be further improved. In particular, while suppressing the carbohydrazide content in the carbohydrazide-containing composition from being relatively low, the above effects are obtained, and the stability of the carbohydrazide contained in the carbohydrazide-containing composition is improved. It can be made more excellent.

The content of carbohydrazide in the carbohydrazide-containing composition (in the case of containing a carbohydrazide salt, the content when converted to the carbohydrazide having the chemical structure represented by the above formula (1)) is expressed as X _C [mass %], The content of substance A in the carbohydrazide-containing composition (when substance A contains a salt of the above compound, the total content when converted to the compound as an acid that is not a salt) X _A [ Mass%], the relationship of 0.0001 ≦ X _A / X _C is preferably satisfied, the relationship of 0.0005 ≦ X _A / X _C ≦ 10 is more preferably satisfied, and 0.001 ≦ It is more preferable to satisfy the relationship of X _A / X _C ≦ 2.0.

  Thereby, both the activity and stability can be maintained in a high state even when the carbohydrazide is exposed to the atmospheric environment or in a solution state.

<Liquid medium>
The carbohydrazide-containing composition of the present invention may contain carbohydrazide and substance A as described above, but may contain a liquid medium having a function of dissolving or dispersing them.

  Thereby, for example, the carbohydrazide-containing composition can be made into a liquid composition, and the ease of handling of the carbohydrazide-containing composition is improved.

  The liquid medium is not particularly limited as long as it is a liquid component that functions as a solvent or a dispersion medium for dissolving or dispersing carbohydrazide as a solute or dispersoid, and substance A. Examples of the liquid medium include water Ketone compounds such as methyl ethyl ketone (MEK), acetone, diethyl ketone, methyl isobutyl ketone (MIBK), methyl isopropyl ketone (MIPK), cyclohexanone, 3-heptanone, 4-heptanone; methanol, ethanol, n-propanol, isopropanol, n-butanol, i-butanol, t-butanol, 3-methyl-1-butanol, 1-pentanol, 2-pentanol, n-hexanol, cyclohexanol, 1-heptanol, 1-octanol, 2-octanol, 2 -Methoxyethano Monohydric alcohols such as ru, allyl alcohol, furfuryl alcohol and phenol, alcohol compounds such as polyhydric alcohols such as ethylene glycol, propylene glycol, butylene glycol and glycerin; diethyl ether, dipropyl ether, diisopropyl ether, dibutyl ether, 1,2-dimethoxyethane (DME), 1,4-dioxane, tetrahydrofuran (THF), tetrahydropyran (THP), anisole, diethylene glycol dimethyl ether (diglyme), 2-methoxyethanol, and polyhydric alcohol condensates (multiple Hydric alcohol ether), the polyhydric alcohol or alkyl ether of the polyhydric alcohol ether (for example, methyl ether, ethyl ether, butyl ether, hexyl ether). Ether compounds such as methyl cellosolve, cellosolve compounds such as methyl cellosolve and phenyl cellosolve; aliphatic hydrocarbon compounds such as hexane, pentane, heptane, cyclohexane, methylcyclohexane, octane, didecane, methylcyclohexene, isoprene, etc. Aromatic hydrocarbon compounds such as toluene, xylene, benzene, ethylbenzene, and naphthalene; aromatics such as pyridine, pyrazine, furan, pyrrole, thiophene, 2-methylpyridine, 3-methylpyridine, 4-methylpyridine, and furfuryl alcohol Group heterocyclic compounds: Amide compounds such as N, N-dimethylformamide (DMF) and N, N-dimethylacetamide (DMA); Dichloromethane, chloroform, 1,2-dichloroethane, trichloroeth Halogen compounds such as lene and chlorobenzene; acetylacetone, ethyl acetate, methyl acetate, isopropyl acetate, isobutyl acetate, isopentyl acetate, ethyl chloroacetate, butyl chloroacetate, isobutyl chloroacetate, ethyl formate, isobutyl formate, ethyl acrylate, methacryl Ester compounds such as methyl acid and ethyl benzoate; amine compounds such as trimethylamine, hexylamine, triethylamine and aniline; nitrile compounds such as acrylonitrile and acetonitrile; nitro compounds such as nitromethane and nitroethane; acetaldehyde, propionaldehyde and butyl Examples include aldehyde-based compounds such as aldehyde, pentanal, and acrylic aldehyde, and one or more selected from these are used in combination. Door can be.

  When the carbohydrazide-containing composition contains a liquid medium, it is preferable that the liquid medium contains a highly hydrophilic compound (for example, a compound compatible with water at an arbitrary ratio), and contains water. More preferably.

  Accordingly, carbohydrazide and substance A can be contained in a dissolved state in the carbohydrazide-containing composition, and unintentional aggregation of carbohydrazide and substance A (for example, the carbohydrazide-containing composition is a dispersion. In this case, the dispersoids constituting the dispersion liquid aggregate to produce coarse solids, which can prevent the dispersion stability and precipitate from being effectively prevented. When applied to such liquids, it is possible to effectively prevent unintentional variations and errors in the amount of carbohydrazide and substance A added to the liquid. In addition, water is advantageous in that it is easily available and is a highly safe substance. In addition, carbohydrazide generally has a problem that the unintentional chemical reaction described above is particularly likely to proceed in a solution state or the like, but in the present invention, the carbohydrazide-containing composition contains water. Even if it exists, generation | occurrence | production of such a problem can be suppressed effectively.

When the liquid medium constituting the carbohydrazide-containing composition contains water, the ratio of water to the entire liquid medium contained in the carbohydrazide-containing composition is preferably 50% by mass or more, and 80% by mass. % Or more is more preferable, and it is further more preferable that it is 90 mass% or more.
Thereby, the effects as described above are more remarkably exhibited.

<Specific amine substances>
The carbohydrazide-containing composition is a group consisting of methoxypropylamine (MOPA), 2-amino-2-methyl-1-propanol (AMP), butoxypropylamine (BPA), diethylhydroxylamine (DEHA) and morpholine (MOR). The specific amine type material which consists of at least 1 sort (s) selected from these may be included.

  By including such a specific amine-based substance together with the aforementioned substance A, they act synergistically, more effectively suppress the generation of foreign substances, and more suitably maintain the activity of carbohydrazide over a long period of time. be able to.

The specific amine material is selected from the group consisting of methoxypropylamine (MOPA), 2-amino-2-methyl-1-propanol (AMP), butoxypropylamine (BPA), diethylhydroxylamine (DEHA), and morpholine (MOR). At least one selected from the group consisting of methoxypropylamine (MOPA), 2-amino-2-methyl-1-propanol (AMP) and butoxypropylamine (BPA) may be used. It is preferable that methoxypropylamine (MOPA) is included, and it is more preferable that methoxypropylamine (MOPA) is included as a main component.
Thereby, the effects as described above are more remarkably exhibited.

In the carbohydrazide-containing composition of the present invention, at least a part of the specific amine substance may be present in a salt state.
Examples of the salt of the specific amine substance include the salt with the substance A described above.

  When the carbohydrazide-containing composition contains a salt of a specific amine-based substance and substance A, precipitation of foreign matters is more effective even when the carbohydrazide is exposed to the air environment or in a solution state. Can be suppressed.

The content of methoxypropylamine (MOPA) with respect to the whole of the specific amine substance contained in the carbohydrazide-containing composition (when the specific amine substance contains a salt of the above compound, it is converted into the compound as an amine that is not a salt) Content) is preferably 50% by mass or more, more preferably 70% by mass or more, and still more preferably 90% by mass or more.
Thereby, the effects as described above are more remarkably exhibited.

  When the substance A and the specific amine substance are used in combination, the content of the specific amine substance in the carbohydrazide-containing composition (in the case where the specific amine substance contains a salt of the above compound, The content when converted to a compound is preferably 0.0001% by mass or more and 5.0% by mass or less, more preferably 0.0005% by mass or more and 2.0% by mass or less. More preferably, it is 001 mass% or more and 0.5 mass% or less.

  Thereby, the stability of carbohydrazide can be further improved, and the activity of carbohydrazide can be more suitably maintained.

When the substance A and a specific amine substance are used in combination, the content of the substance A in the carbohydrazide-containing composition (when the substance A contains a salt of the above compound, it is converted into the compound as an acid that is not a salt) X _A [mass%], the content of the specific amine substance in the carbohydrazide-containing composition (when the specific amine substance contains a salt of the above compound, when the content) when converted into the compound was _{X B} [wt%], it is preferable to satisfy the relation of _{0.001 ≦ X B / X a ≦} 0.80, 0.002 ≦ X B / It is more preferable to satisfy the relationship of X _A ≦ 0.70, and it is further preferable to satisfy the relationship of 0.005 ≦ X _B / X _A ≦ 0.50.

  Thereby, the stability of carbohydrazide can be further improved, and the activity of carbohydrazide can be more suitably maintained.

<Other ingredients>
The carbohydrazide-containing composition of the present invention may contain components other than the above (other components).

  Examples of such components include pH adjusters (sodium hydroxide, sodium phosphate, etc.), other anticorrosive agents (oxycarboxylic acid, etc.), other oxygen scavengers (sodium sulfite, etc.), chelating agents, antioxidants. , Excipient, thickener, gelling agent, colorant, filler, binder, solubilizer, preservative, wetting agent, surfactant, emulsifier, dispersant, emulsion, solution, suspension Agents, fragrances, fragrances, coating agents, desiccants and the like.

  The form of the carbohydrazide-containing composition is not particularly limited, and examples thereof include a tablet form, a powder form (including granules), a liquid form, a gel form, and a paste form.

  When the carbohydrazide-containing composition is a liquid containing water, the pH of the carbohydrazide-containing composition is preferably 5.0 or more and 14 or less, more preferably 5.5 or more and 13 or less. And more preferably 6.0 or more and 12 or less.

  Thereby, the production | generation of hydrazine etc. by decomposition | disassembly of unintentional carbohydrazide can be suppressed more effectively.

  In addition, unless otherwise indicated, the value of pH shown in this specification is a value in 23 degreeC.

<Usage form of carbohydrazide-containing composition>
Next, the usage form of the carbohydrazide-containing composition of the present invention will be described.

  The carbohydrazide-containing composition of the present invention can be used, for example, as an anticorrosive for various cooling water systems and boiler systems, a deoxidizer, a crosslinking agent for synthetic resins, a curing agent, and the like.

  In particular, the carbohydrazide-containing composition of the present invention is preferably applied to a boiler system.

  The boiler system includes a member (pipe or the like) that comes into contact with a liquid, and easily causes problems such as corrosion. In the boiler system, the carbohydrazide contained in the carbohydrazide-containing composition of the present invention is hydrazine under an environment such as high temperature and high pressure (for example, temperature: 120 ° C. or higher, pressure: 0.2 MPa or higher). Change and exert the function of effectively removing dissolved oxygen. Therefore, when the carbohydrazide-containing composition of the present invention is applied to a boiler system, the functions of carbohydrazide as an anticorrosive and oxygen scavenger can be more effectively exhibited.

  Examples of the liquid constituting the boiler system include boiler water and feed water introduced into the boiler, and the carbohydrazide-containing composition of the present invention can be suitably applied to these liquids.

  Further, when the carbohydrazide-containing composition of the present invention is applied to a boiler system, the carbohydrazide-containing composition of the present invention is a liquid other than the liquid used during operation of the boiler (for example, a state where the boiler is stopped). It may be applied to a liquid that fills the boiler during so-called full water storage.

  When the carbohydrazide-containing composition of the present invention is applied to a boiler system, the maximum temperature in the liquid use state (operational state of the boiler system) to which the carbohydrazide-containing composition is applied is 120 ° C or higher. It is preferable that the temperature is 130 ° C. or higher and 374 ° C. or lower, more preferably 140 ° C. or higher and 366 ° C. or lower.

  When the carbohydrazide-containing composition of the present invention is applied to a boiler system, the maximum pressure in a liquid use state (operational state of the boiler system) to which the carbohydrazide-containing composition is applied is 0.2 MPa or more. Preferably, the pressure is 0.3 MPa or more and 22.1 MPa or less, and more preferably 0.4 MPa or more and 20 MPa or less.

  When the carbohydrazide-containing composition is used by being mixed with a liquid, the components of the carbohydrazide-containing composition such as carbohydrazide and substance A are diluted.

  The content of carbohydrazide in the mixture of the carbohydrazide-containing composition and the liquid is preferably 0.0000001 mass% (1 ppb) or more and 0.002 mass% (20 ppm) or less, and 0.0000002 mass % (2 ppb) or more and 0.0015 mass% (15 ppm) or less, more preferably 0.0000004 mass% (4 ppb) or more and 0.0010 mass% (10 ppm) or less.

  Thereby, the function of carbohydrazide can be more effectively exhibited while sufficiently exhibiting the original function required for the liquid. Moreover, it is advantageous also in preventing that the cost concerning a carbohydrazide containing composition becomes higher than necessary.

  The carbohydrazide-containing composition of the present invention may be directly mixed with the liquid, or diluted with a dedicated dilution liquid or tap water (dilution liquid) before mixing with the liquid. May be used.

[Method for stabilizing carbohydrazide]
Next, the method for stabilizing carbohydrazide of the present invention will be described.

  The method for stabilizing carbohydrazide according to the present invention is characterized in that a composition containing carbohydrazide contains substance A consisting of at least one selected from the group consisting of erythorbic acid, ascorbic acid, sorbic acid and benzoic acid. And

  As a result, the substance A coexists in the composition containing carbohydrazide (the carbohydrazide-containing composition of the present invention described above is obtained), improving the stability of the carbohydrazide and exposing the carbohydrazide to the atmospheric environment. It is possible to make it difficult for the foreign matter to be precipitated even in a state of being made into a solution or in a solution state.

  The composition containing carbohydrazide to contain the substance A may be substantially composed of only carbohydrazide, or may contain other components (for example, carbohydrazide such as the above-mentioned liquid medium). It may contain a component of the composition (excluding the substance A).

  Further, when the substance A is contained (mixed) in the composition containing carbohydrazide, the substance A may be used in a state where it is not mixed with other components, for example, or other components (for example, You may use in the state mixed with the structural component (however, except carbohydrazide) etc. of carbohydrazide containing compositions, such as the liquid medium mentioned above.

  As mentioned above, although preferred embodiment of this invention was described, this invention is not limited to these.

  Hereinafter, the present invention will be described in more detail with specific examples. However, the present invention is not limited to the following examples. In the following description, the treatment that does not particularly indicate the temperature condition and the humidity condition is performed at room temperature (23 ° C.) and a relative humidity of 50%. As for various measurement conditions, those not particularly showing the temperature condition and the humidity condition are numerical values at room temperature (23 ° C.) and a relative humidity of 50%.

[1] Production of carbohydrazide-containing composition (Example 1)
Carbohydrazide, sodium erythorbate, and ion-exchanged water (pure water) were mixed at a predetermined ratio.

(Example 2)
Carbohydrazide, erythorbic acid (not a salt), and ion-exchanged water (pure water) were mixed at a predetermined ratio.

(Example 3)
Carbohydrazide and erythorbic acid (not a salt) were mixed at a predetermined ratio.

(Example 4)
Carbohydrazide, ascorbic acid (not a salt), and ion-exchanged water (pure water) were mixed at a predetermined ratio.

(Example 5)
Carbohydrazide, sorbic acid (not a salt), and ion-exchanged water (pure water) were mixed at a predetermined ratio.

(Example 6)
Carbohydrazide, benzoic acid (not a salt), and ion-exchanged water (pure water) were mixed at a predetermined ratio.

(Example 7)
Carbohydrazide, sodium benzoate, and ion-exchanged water (pure water) were mixed at a predetermined ratio.

(Example 8)
Carbohydrazide, erythorbic acid (not a salt), methoxypropylamine (not a salt), and ion-exchanged water (pure water) were mixed at a predetermined ratio.

Example 9
Carbohydrazide, ascorbic acid (not a salt), methoxypropylamine (not a salt), and ion-exchanged water (pure water) were mixed at a predetermined ratio.

(Example 10)
Carbohydrazide, sorbic acid (not a salt), methoxypropylamine (not a salt), and ion-exchanged water (pure water) were mixed at a predetermined ratio.

(Example 11)
Carbohydrazide, benzoic acid (not a salt), methoxypropylamine (not a salt), and ion-exchanged water (pure water) were mixed at a predetermined ratio.

(Example 12)
Carbohydrazide, erythorbic acid (not a salt), ascorbic acid (not a salt), methoxypropylamine (not a salt), 2-amino-2-methyl-1-propanol (not a salt), Ion exchange water (pure water) was mixed at a predetermined ratio.

(Example 13)
Carbohydrazide, erythorbic acid (not a salt), 2-amino-2-methyl-1-propanol (not a salt), and ion-exchanged water (pure water) were mixed at a predetermined ratio.

(Example 14)
Carbohydrazide, erythorbic acid (not a salt), butoxypropylamine (not a salt), and ion-exchanged water (pure water) were mixed at a predetermined ratio.

(Example 15)
Carbohydrazide, erythorbic acid (not a salt), diethylhydroxylamine (not a salt), and ion-exchanged water (pure water) were mixed at a predetermined ratio.

(Example 16)
Carbohydrazide, erythorbic acid (not a salt), morpholine (not a salt), and ion-exchanged water (pure water) were mixed at a predetermined ratio.

(Examples 17 to 20)
It was manufactured in the same manner as in Example 2 except that the blending ratio of each component was changed.

(Comparative Example 1)
The procedure was the same as Example 1 except that the substance A was not used.

(Comparative Examples 2-6)
The same procedure as in Example 1 was conducted except that other components were used instead of sodium erythorbate so that the composition shown in Table 1 was obtained.

(Comparative Example 7)
Carbohydrazide was used as a carbohydrazide-containing composition as it was.

  Table 1 summarizes the compounding ratios of the components used for the preparation of the compositions of the Examples and Comparative Examples. In Table 1, erythorbic acid is “A1”, ascorbic acid is “A2”, sorbic acid is “A3”, benzoic acid is “A4”, methoxypropylamine is “MOPA”, 2-amino-2-methyl- 1-propanol “AMP”, butoxypropylamine “BPA”, diethylhydroxylamine “DEHA”, morpholine “MOR”, mequinol “A1 ′”, 1,4-benzoquinone “A2 ′”, hydroquinone “A3 ′”, tert-butylquinone is indicated by “A4 ′”, and 4-tert-butylpyrocaterol is indicated by “A5 ′”. In Table 1, the content of carbohydrazide indicates the content when converted to carbohydrazide having the chemical structure represented by the above formula (1) when the carbohydrazide salt is included. In the case where the substance A contains a salt of the above compound, the content ratio of the specific amine-based substance is indicated by the content ratio when converted into the compound as an acid that is not a salt. In the case where the substance contains a salt of the above compound, the content when converted into the compound as an amine that is not a salt is shown.

[2] Evaluation [2-1] Effect of suppressing precipitation of foreign matter [2-1-1] Effect of suppression at each temperature Each of the carbohydrazide-containing compositions of the respective Examples and Comparative Examples is a plurality of predetermined ones. In a sealed state in a container (polypropylene container), it was allowed to stand in an environment of 4 ° C, room temperature (23 ° C), and 40 ° C.

  The state of the carbohydrazide-containing composition after 365 days was visually observed, and the deposition of foreign substances was evaluated according to the following criteria. In Example 3 and Comparative Example 7 that were in a solid state immediately after production, ion-exchanged water (pure water) was added so that the content of carbohydrazide was 10% by mass after standing in the above environment for 365 days. And the mixture was observed.

A: No precipitation of foreign matter is observed.
B: Almost no foreign matter is deposited.
C: Slight precipitation of foreign matter is observed.
D: Precipitation of foreign matters is clearly recognized.
E: Precipitation of foreign matters is noticeable.

[2-1-2] Stable days at room temperature The carbohydrazide-containing compositions of the respective Examples and Comparative Examples were placed in a predetermined container (polypropylene container) and sealed, at room temperature (23 The carbohydrazide-containing composition was visually observed every 24 hours, and the number of days until foreign matters were precipitated in the carbohydrazide-containing composition was determined and evaluated according to the following criteria.

A: Precipitation of foreign matters is not observed when 401 days have passed.
B: Foreign matter precipitated in 201 days or more and 400 days or less.
C: Foreign matter was precipitated in 81 days or more and 200 days or less.
D: Foreign matter precipitated in 25 days or more and 80 days or less.
E: Foreign matter precipitated in 24 days or less.
These results are summarized in Table 2.

  As is apparent from Table 2, the carbohydrazide-containing composition of the present invention is less likely to precipitate foreign matter even in a state exposed to the air environment, in a solution state, etc., and has an activity after being stored for a predetermined period. Was also excellent. That is, the carbohydrazide-containing composition of the present invention was excellent in storage stability, and was able to suitably maintain activity while suppressing the precipitation of foreign matters. On the other hand, satisfactory results were not obtained in the comparative example.

Claims (6)

Carbohydrazide,
A carbohydrazide-containing composition comprising: substance A consisting of at least one selected from the group consisting of erythorbic acid, ascorbic acid, sorbic acid and benzoic acid.   The carbohydrazide-containing composition according to claim 1, wherein at least a part of the substance A is contained in the carbohydrazide-containing composition in a salt state. When the content of the carbohydrazide in the carbohydrazide-containing composition is X _C [mass%] and the content of the substance A in the carbohydrazide-containing composition is X _A [mass%], 0.0001 ≦ X carbohydrazide containing composition according to claim 1 or 2 satisfying the relation of _{a /} X _C.   The carbohydrazide-containing composition according to any one of claims 1 to 3, wherein the carbohydrazide-containing composition has a function of removing dissolved oxygen contained in the liquid.   The carbohydrazide-containing composition according to any one of claims 1 to 4, wherein the carbohydrazide-containing composition is applied to a boiler system.   A method for stabilizing carbohydrazide, comprising containing a substance A consisting of at least one selected from the group consisting of erythorbic acid, ascorbic acid, sorbic acid and benzoic acid in a composition containing carbohydrazide.