阅读说明：本技术 氧化锡形成组合物 (Tin oxide forming composition ) 是由 崔瀞颢 黄仁星 朴训民 李东哲 黃教贤 金洸贤 方晸业 于 2020-09-14 设计创作，主要内容包括：本发明提供一种氧化锡形成组合物和使用该氧化锡形成组合物的氧化锡形成方法。本发明的氧化锡形成组合物容易制造并且可以以高收率形成氧化锡。(The invention provides a tin oxide forming composition and a tin oxide forming method using the same. The tin oxide-forming composition of the present invention is easy to manufacture and can form tin oxide in high yield.)

1. A tin oxide-forming composition comprising:

a tin precursor;

sulfate ions; and

a solvent, a water-soluble organic solvent,

wherein the molar ratio of sulfate ion to tin, i.e., sulfate ion/tin, is 1 or more.

2. The tin oxide-forming composition of claim 1, wherein the molar ratio of sulfate ions to tin, sulfate ions/tin, is from 3 to 10.

3. The tin oxide-forming composition of claim 1, wherein the tin precursor is at least one selected from the group consisting of tin ions, tin halide compounds, tin alkoxide compounds, tin acetate, tin sulfate, and tin 2-ethylhexanoate.

4. The tin oxide-forming composition of claim 1, wherein the solvent is at least one selected from the group consisting of water, an alcohol, and a ketone.

5. The tin oxide-forming composition of claim 1, wherein the concentration of sulfate ions in the tin oxide-forming composition is from 0.01M to 10M.

6. The tin oxide-forming composition of claim 1, wherein the concentration of tin ions in the tin oxide-forming composition is from 0.01M to 10M.

7. The tin oxide-forming composition of claim 1, further comprising a platinum group element precursor.

8. The tin oxide-forming composition of claim 7, wherein the platinum group element precursor is selected from ruthenium hexafluoride (RuF)₆) Ruthenium (III) chloride (RuCl)₃) Ruthenium (III) chloride hydrate (RuCl)₃·xH₂O), ruthenium (III) nitrosyl chloride (Ru (NO) Cl₃) Hexaammine ruthenium (III) chloride (Ru (NH)₃)₆Cl₃) Ruthenium (III) bromide (RuBr)₃) Ruthenium (III) bromide hydrate (RuBr)₃·xH₂O), ruthenium iodide (RuI)₃) And ruthenium acetate.

9. The tin oxide-forming composition of claim 7, wherein the platinum group element precursor is selected from iridium chloride hydrate (IrCl)₃·xH₂O) and hydrogen hexachloroiridate hexahydrate (H)₂IrCl₆·6H₂O) is used.

10. A tin oxide forming method comprising: a step (S1) of sintering the tin oxide-forming composition according to claim 1 at a temperature of 480 ℃ or higher.

11. The tin oxide forming method of claim 10, further comprising: a step of drying the tin oxide-forming composition at a temperature of 50 ℃ to 300 ℃ prior to the sintering.

12. The tin oxide forming method of claim 10, wherein the sintering is performed for 30 to 120 minutes.

13. The tin oxide forming method according to claim 10, wherein a temperature of the sintering is 550 ℃ or higher.

Technical Field

Cross Reference to Related Applications

This application claims the benefit of korean patent application No.10-2019-0119109, filed by the korean intellectual property office at 26.9.2019, the disclosure of which is incorporated herein by reference in its entirety.

Technical Field

The present invention relates to a tin oxide-forming composition capable of forming tin oxide in high yield, and a tin oxide-forming method using the tin oxide-forming composition.

Background

Techniques for electrolyzing low cost brines such as seawater to produce hydroxides, hydrogen, and chlorine are well known. This electrolytic process is also commonly referred to as the chloralkali process and can be considered a process that has proven the performance and reliability of the technology through commercial operations for decades.

For electrolysis of brine, the ion exchange membrane method is most widely used in recent years, in which an ion exchange membrane is installed inside an electrolytic cell such that the electrolytic cell is divided into a cation chamber and an anion chamber, and brine is used as an electrolytic solution to obtain chlorine gas from an anode and hydrogen and caustic soda from a cathode.

On the other hand, the chloralkali process of brine proceeds through reactions as shown in the electrochemical scheme.

And (3) anode reaction: 2Cl^-→Cl₂+2e^-(E⁰＝+1.36V)

And (3) cathode reaction: 2H₂O+2e^-→2OH^-+H₂(E⁰＝-0.83V)

And (3) overall reaction: 2Cl^-+2H₂O→2OH^-+Cl₂+H₂(E⁰＝-2.19V)

In the electrolysis of brine, the theoretical voltage required for the electrolysis of brine as well as the overvoltage of the anode, the overvoltage of the cathode, the voltage due to the resistance of the ion exchange membrane, and the voltage due to the distance between the anode and the cathode should be considered for the electrolysis voltage, and among these, the overvoltage due to the electrode has served as an important variable.

Therefore, research into a method that can reduce overvoltage of an electrode has been conducted, and for example, a noble metal-based electrode called a Dimensionally Stable Anode (DSA) has been developed and used as an anode, while for a cathode, development of an excellent material having durability and low overvoltage is required.

Stainless steel or nickel has been mainly used as a cathode, and in order to reduce overvoltage, a method of coating the surface of stainless steel or nickel with nickel oxide, an alloy of nickel and tin, a combination of activated carbon and an oxide, ruthenium oxide, platinum, or the like and using it has been recently studied.

However, in the method of introducing the coating layer to the electrode surface as described above, there is a problem in the case of introducing the coating layer containing tin. Due to the high volatility of the intermediate products that can be produced during the introduction of the coating, the yield of tin in the coating is low, the composition of the coating is also not uniform, and the scattered coating can cause equipment contamination. In order to solve this problem, a tin precursor having a complex ion is sometimes used, but in this case, since a complicated synthesis process is required, it is difficult to prepare the precursor and the cost increases.

Documents of the prior art

(patent document 1) KR 2017-0086104A

(patent document 2) KR 2006-0052940A

Disclosure of Invention

Technical problem

An aspect of the present invention is to provide a tin oxide-forming composition capable of forming tin oxide in high yield while being simple to manufacture, and a tin oxide-forming method using the same.

Technical scheme

In order to solve the above problems, the present invention provides a tin oxide-forming composition comprising: a tin precursor, sulfate ions, and a solvent, and the molar ratio of sulfate ions to tin (sulfate ions/tin) is 1 or more. Further, the present invention provides a tin oxide forming method including: and a step (S1) in which the tin oxide-forming composition is sintered at a temperature of 480 ℃ or higher.

Advantageous effects

The tin oxide-forming composition according to the present invention is easy to manufacture and economical, and the composition can form tin oxide in high yield and can be equally applied to existing electrode manufacturing processes.

Drawings

Fig. 1 shows XRD patterns when tin oxide-forming compositions according to embodiments of the present invention are sintered at different temperatures.

Detailed Description

Hereinafter, the present invention will be described in more detail so that the present invention can be more clearly understood.

It should be understood that the words or terms used in the specification and claims should not be construed as meaning defined in commonly used dictionaries. It should also be understood that the words or terms should be construed as having meanings consistent with their meanings in the background of the related art and the technical idea of the present invention, based on the principle that the inventor can appropriately define the meanings of the words or terms to best explain the present invention.

Tin oxide forming composition

The inventors of the present invention have found that, when a tin precursor and a sulfate ion are present simultaneously and the molar ratio of the sulfate ion to tin in the composition is 1 or more, volatilization of an intermediate product in the formation of tin oxide from the tin precursor can be suppressed, whereby the yield of tin oxide finally formed can be significantly improved, thereby completing the present invention.

Specifically, the present invention provides a tin oxide-forming composition comprising: a tin precursor, sulfate ions, and a solvent, and the molar ratio of sulfate ions to tin (sulfate ions/tin) is 1 or more.

The tin oxide is formed from a tin precursor, and the tin precursor may be used as long as it can be converted into tin oxide under high-temperature conditions. For example, the tin precursor may be an ion of tin itself, that is, a tin ion, or a tin halide compound including tin (II or IV) chloride (including a hydrate of the tin halide compound), or a tin alkoxide compound including tin isopropoxide, or a compound selected from tin acetate, tin sulfate, and tin 2-ethylhexanoate. In the case of using such a tin precursor, since the tin precursor can be uniformly distributed in the solvent while tin oxide is easily formed thereafter, tin oxide having uniform physical properties can be formed.

The concentration of the tin precursor in the tin oxide-forming composition may vary depending on the type of tin precursor, the type of solvent, and the solubility of the tin precursor in the solvent. However, the concentration may be generally 0.01M to 10M, preferably 0.05M to 5M, based on tin ions. If the concentration of the tin precursor is less than the above range, the amount of tin oxide formed is small, and thus, it is uneconomical in terms of cost. On the other hand, when the concentration of the tin precursor is more than the above range, the amount of sulfate ion added in the composition excessively increases, making it difficult to perform treatment in the manufacturing step or after the manufacturing. In addition, in some cases, precipitation may occur, whereby tin oxide cannot be uniformly prepared.

Sulfate ion (SO)₄ ^2-) For suppressing volatilization of an intermediate product generated during formation of tin oxide from a tin precursor, thereby improving the yield of the finally produced tin oxide. The sulfate ion may be added to the solvent in the form of a compound capable of dissolving in the solvent to produce a sulfate ion. For example, it can be prepared by mixing a compound selected from sulfuric acid (H)₂SO₄) Sodium sulfate (Na)₂SO₄) Sulfur, sulfurCalcium carbonate (CaSO)₄) Potassium sulfate (K)₂SO₄) And ammonium sulfate ((NH)₄)₂SO₄) Is dissolved in a solvent to produce sulfate ions.

The concentration of sulfate ions in the tin oxide-forming composition can vary depending on the type and concentration of tin precursor or the type of solvent in the composition, but can generally be from 0.01M to 10M, preferably from 0.05M to 5M. When the concentration of the sulfate ion is less than the above range, the function of the sulfate ion is not sufficiently exhibited, and the yield of tin oxide may decrease. On the other hand, when the concentration of the sulfate ion is more than the above range, the sulfate ion cannot be removed properly in the mild drying-sintering process, and thus, it acts as a large amount of impurities.

Meanwhile, the molar ratio of sulfate ion to tin (sulfate ion/tin) in the composition provided by the present invention may be 1 or more, preferably 3 or more, and 20 or less or 15 or less, preferably 10 or less. When the molar ratio of the sulfate ion component to the tin component in the composition is less than the above range, the above function of the sulfate ion is not sufficiently realized. Thus, the yield of tin oxide formed from the composition of the present invention may be low. In addition, conversely, when the molar ratio of the sulfate ion component to the tin component in the composition is larger than the above range, there is a problem that the sulfate ion existing in excess remains as an impurity even after the tin oxide is formed.

The solvent serves to uniformly dissolve the tin precursor and sulfate ions. As the solvent, any solvent can be used without particular limitation as long as it has solubility to the tin precursor and sulfate ion and does not adversely affect tin oxide generation in the subsequent tin oxide generation step, and can be easily removed. Specifically, at least one selected from the group consisting of water, an alcohol (e.g., ethanol, isopropanol, or n-butanol), and a ketone (e.g., dimethyl ketone, diethyl ketone, or methyl ethyl ketone) may be used as the solvent. Specifically, at least one selected from the group consisting of water, ethanol, isopropanol, n-butanol, and methyl ethyl ketone is preferable. When such a solvent is used, the stability of the tin oxide-forming composition can be ensured, and tin oxide can be uniformly formed thereafter.

Meanwhile, the solvent may further include additional components to improve dispersibility of the dissolved solute or to improve solubility. For example, ethoxyethanol or butoxyethanol may also be included to improve the dispersibility of the solute, and hydrochloric acid or hydrogen peroxide may also be included to improve the solubility.

In the present invention, the tin oxide-forming composition may further include a platinum group element precursor. When the tin oxide-forming composition further includes a platinum group element precursor, a composite metal oxide including tin oxide and an oxide of a platinum group element may be finally formed.

As the platinum group element precursor, a ruthenium precursor and/or an iridium precursor may be used. Specifically, when the platinum group element precursor is a ruthenium precursor, at least one compound selected from ruthenium iodide and ruthenium acetate may be used as the platinum group element precursor. Specifically, when the platinum group element precursor is a ruthenium precursor, a ruthenium compound selected from ruthenium hexafluoride (RuF) may be used₆) Ruthenium (III) chloride (RuCl)₃) Ruthenium (III) chloride hydrate (RuCl)₃·xH₂O), ruthenium (III) nitrosyl chloride (Ru (NO) Cl₃) Hexaammine ruthenium (III) chloride (Ru (NH)₃)₆Cl₃) Ruthenium (III) bromide (RuBr)₃) Ruthenium (III) bromide hydrate (RuBr)₃·xH₂O), ruthenium iodide (RuI)₃) And ruthenium acetate as a platinum group element precursor, and further, preferably, ruthenium (iii) chloride hydrate (RuCl) may be used₃·xH₂O), ruthenium (III) nitrosyl chloride (Ru (NO) Cl₃) Hexaammine ruthenium (III) chloride (Ru (NH)₃)₆Cl₃) And ruthenium acetate. In the case of using the ruthenium precursor listed above, there are advantages in that a composite metal oxide containing ruthenium oxide and tin oxide is easily formed, and the yield is high.

Meanwhile, in the present invention, when the platinum group element precursor is an iridium precursor, a compound selected from iridium chloride hydrate (IrCl) may be used₃·xH₂O) and hydrogen hexachloroiridate hexahydrate (H)₂IrCl₆·6H₂At least one compound of O) as platinum group elementA precursor of a hormone. As in the case of the ruthenium precursor, when the iridium precursor listed above is used, there are advantages in that a complex metal oxide containing iridium oxide and tin oxide is easily formed, and the yield is high.

Tin oxide forming method

The present invention provides a tin oxide forming method using the tin oxide forming composition. Specifically, the present invention provides a tin oxide forming method, including: and (S1) sintering the tin oxide-forming composition at a temperature of 480 ℃ or higher.

Due to the high temperature sintering in this step, the tin precursor is converted to tin oxide in the presence of sulfate ions, and the sintering temperature may be 480 ℃ or higher, preferably 550 ℃ or higher, in order to provide sufficient energy for the conversion. If the sintering temperature is lower than the above temperature, sufficient energy required for conversion into an oxide cannot be supplied, and thus, uniform tin oxide cannot be formed. Specifically, when the sintering temperature is 550 ℃ or higher, tin oxide can be formed and sulfate ions contained in the tin oxide-forming composition can be smoothly removed.

The sintering in this step may be performed for 30 minutes or more, preferably 60 minutes or more. When the sintering time is shorter than the above time, tin oxide cannot be sufficiently formed.

The sintering in this step may be performed immediately in the state of the composition, or may be performed after the composition is applied to another object. For example, the tin oxide-forming composition can be coated on a metal substrate and then sintered to form a coating comprising tin oxide on the surface of the metal substrate. The coating may be performed by any one method selected from, for example, doctor blade, die casting, comma coating, screen printing, spraying, electrospinning, roll coating, and brush coating. In the case where the composition is coated and then sintered as described above, the process of coating and sintering may be repeated a plurality of times.

The tin oxide forming method of the present invention may further include drying at a temperature of 50 to 300 ℃, preferably 50 to 200 ℃, before sintering (S0). When a drying step before sintering is performed, tin oxide can be more easily formed. The drying may be carried out for 5 to 60 minutes, preferably for 5 to 30 minutes.

Hereinafter, examples and experimental examples are described in more detail in order to illustrate the present invention in more detail, but the present invention is not limited to these examples and experimental examples. The embodiments according to the present invention may be modified in various forms, and the scope of the present invention should not be construed as being limited to the described embodiments. Embodiments of the present invention are provided to more fully describe the present invention to those of ordinary skill in the art.

[ example 1]

By reacting tin (II) chloride dihydrate with sulfuric acid (H)₂SO₄) Dissolved in deionized water as a solvent to prepare a tin oxide-forming composition. Sulfate ion (SO) in said composition₄ ^2-) The molar ratio to the tin component was set to 3.

[ example 2]

A tin oxide-forming composition was prepared in the same manner as in example 1, except that tin 2-ethylhexanoate was dissolved as a tin precursor.

[ example 3]

Except for direct dissolution of tin sulfate (SnSO)₄) Except that, a tin oxide-forming composition was prepared in the same manner as in example 1.

[ example 4]

A tin oxide-forming composition was prepared by dissolving ruthenium chloride trihydrate, iridium chloride trihydrate and tin (II) chloride dihydrate in an excess of 1M aqueous sulfuric acid so that the molar ratio of Ru: Ir: Sn was 35:20: 45. Sulfate ion (SO) in said composition₄ ^2-) The molar ratio to the tin component was set to 8.

[ example 5]

A tin oxide-forming composition was prepared in the same manner as in example 4, except that tin sulfate was directly dissolved as a tin precursor.

Comparative example 1

A tin oxide-forming composition was prepared in the same manner as in example 1, except that sulfuric acid was not dissolved.

Comparative example 2

A tin oxide-forming composition was prepared in the same manner as in example 2, except that sulfuric acid was not dissolved.

Comparative example 3

Except for sulfate ion (SO) in the composition₄ ^2-) A tin oxide-forming composition was prepared in the same manner as in example 1, except that the molar ratio to the tin component was set to 0.7.

Comparative example 4

A tin oxide-forming composition was prepared in the same manner as in example 4, except that n-butanol was used as a solvent.

The components and content ratios of the tin oxide-forming compositions prepared in examples and comparative examples are summarized in table 1.

[ Table 1]

[ Experimental example 1. confirmation of yield of tin oxide-forming composition prepared ]

The tin oxide-forming compositions prepared in examples 1 to 4 and comparative examples 1 to 2 were sintered, and the yield was calculated from the weight of the tin oxide obtained by sintering. The yield was calculated using equation 1 and equation 2, and the results are shown in table 2.

[ equation 1]

Yield { (weight of sample after sintering)/(mole number of Sn in sample before sintering × SnO { (weight of sample after sintering)/(mole number of Sn in sample before sintering) } { (SnO {)₂Molecular weight of) } × 100

Examples 1 to 3 and comparative examples 1 to 2, which contain only a tin precursor as a metal precursor, were calculated using the above equation 1.

[ equation 2]

Yield ═ weight of sample after sintering)/((number of moles of Ru in sample before sintering × RuO₂Molecular weight of) + (number of moles of Ir in the sample before sintering. times. IrO₂Molecular weight of) + (number of moles of Sn in sample before sintering. times. SnO₂Molecular weight of) } × 100

In the case of example 4 containing ruthenium and iridium precursors as metal precursors in addition to tin precursors, the yield was calculated by equation 2.

[ Table 2]

From the above results, it was confirmed that when the tin oxide-forming composition of the example of the present invention containing a tin precursor and a sulfate ion together was sintered, a higher yield was exhibited, and specifically, according to comparative example 3, when the ratio of tin to sulfate ion did not satisfy the range of the present invention, a sufficient degree of yield could not be obtained.

[ Experimental example 2. examination of XRD and yield variation according to sintering temperature ]

In addition, as shown in FIG. 1, XRD was confirmed while changing the sintering temperature to 450 deg.C, 480 deg.C, 530 deg.C, 550 deg.C and 580 deg.C, wherein pure SnO was used₂As a control.

As shown in fig. 1, it was confirmed that tin oxide is not easily formed when the tin oxide-forming composition is sintered at a temperature of less than 480 ℃. On the other hand, it was confirmed that most of the tin precursor was converted into tin oxide at a temperature of 480 ℃ or higher.

In addition, the yield was calculated by sintering the tin oxide-forming composition of example 1 at two different temperatures. The results are shown in Table 3.

[ Table 3]

Sintering temperature (. degree. C.)	Weight of Metal sample (g)	Sample weight after sintering (g)	Yield (%)
				550	1.2063	0.7977	99.0
480	1.0922	0.9774	134.0

From table 3, it was confirmed that when the sintering temperature was less than 550 ℃, the sulfate ion was not completely removed, and thus the yield exceeded 100%. In this regard, as a result of elemental analysis of the resultant obtained when the yield exceeded 100%, the sulfur content was calculated to be 7.6%.

On the other hand, when the sintering temperature was 550 ℃ or higher, most of the sulfate ions were removed, and it was confirmed that the yield converged to 100%. Therefore, in the case of using the tin oxide-forming composition of the present invention, by performing sintering at a relatively low temperature in a region where tin oxide needs to be formed simultaneously irrespective of sulfate ions, the energy used in the sintering process can be reduced. However, it was confirmed that most of the sulfate ions could be removed by sintering at a temperature of 550 ℃ or higher in the region where the removal of sulfate ions is important.

[ Experimental example 3 EDS analysis when coating an electrode ]

The titanium expanded base material treated with white alumina blasting was pretreated in a 10% oxalic acid aqueous solution (90 ℃) for 2 hours to form irregularities, washed with distilled water, and dried to prepare a metal base material. Each of the tin oxide-forming compositions of examples 4 and 5 and comparative example 3 was coated onto the prepared metal substrate. Thereafter, the composition was dried at 70 ℃ and sintered at 550 ℃ for 10 minutes. Repeating the coating and dryingAnd sintering until the coating amount of the composition reaches 20g/m²And then, finally sintered at 550 ℃ for 60 minutes to prepare an electrode. The prepared electrode surfaces were analyzed by EDS to calculate the molar ratio of each metal component present in the electrode coating, as shown in table 4.

[ Table 4]

As a result of the EDS analysis, in examples 4 and 5, the ratio of each metal component of the electrode coating layer was similar to that of each metal precursor in the tin oxide-forming composition, and therefore, most of the tin precursor was converted into an oxide, as with ruthenium and iridium. On the other hand, in comparative example 3, the ratio was different, and it was confirmed that a relatively small amount of tin precursor was converted into tin oxide as compared with ruthenium and iridium.