Pressure medium and method of using pressure medium

Abstract

To provide a pressure medium having a high solidification pressure and a flash point that is sufficiently higher than room temperature.SOLUTION: There is provided a pressure medium containing one or more group 14 element-containing organic compounds selected from a compound represented by a formula (a1) and a compound represented by a formula (a2).SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a pressure medium and a method for using a pressure medium. [Background technology]

[0002] In recent years, research into material synthesis and changes in the physical properties of materials under ultra-high pressures exceeding 1.0 GPa has been widely conducted. In these studies, it is necessary to apply hydrostatically ultra-high pressure to the material, and therefore a pressure medium is usually used when applying ultra-high pressure to the material.

[0003] Under ultra-high pressure, one of the properties required for a pressure medium is that it must be able to maintain a liquid state without solidifying over a wide pressure range. If the pressure medium solidifies during the application of pressure, uniaxiality will be introduced at higher pressures, making uniform compression impossible.

[0004] In recent years, various studies have been conducted on pressure fluids that satisfy these required properties. For example, Patent Document 1 describes that a pressure fluid oil made of 1-olefin oligomer has achieved a solidification pressure of 2.7 GPa at room temperature. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] International Publication No. 2007 / 058064 Summary of the Invention [Problem to be solved by the invention]

[0006] The pressure medium described in Patent Document 1 has a high solidification pressure at room temperature, but in recent years, there has been a demand for the development of a pressure medium with an even higher solidification pressure. In addition, from the viewpoint of safety, the pressure medium is also required to have a flash point that is sufficiently higher than room temperature (for example, 60° C. or higher).

[0007] Therefore, an object of the present invention is to provide a pressure medium having a solidification pressure of more than 2.7 GPa at room temperature and a flash point sufficiently higher than room temperature, and a method for using the pressure medium. In this specification, "room temperature" means 25°C. [Means for solving the problem]

[0008] According to the present invention, the following [1] and [2] are provided. [1] A pressure medium comprising one or more Group 14 element-containing organic compounds (A) selected from the group consisting of compounds (A1) represented by the following general formula (a1) and compounds (A2) represented by the following general formula (a2): [ka] [In the general formula (a1), R a11 , R a12 , R a13 , and R a14 are each independently an alkyl group having 3 to 6 carbon atoms. a1 is a carbon atom or a silicon atom. [ka] [In the general formula (a2), R a21 , R a22 , R a23 , and R a24 are each independently an alkyl group having 3 to 6 carbon atoms. a2 is a silicon atom, a germanium atom, a tin atom, or a lead atom. [2] A method of using a pressure medium, which applies pressure to a substance via the pressure medium described in [1] above. [Effects of the Invention]

[0009] According to the present invention, it is possible to provide a pressure medium having a solidification pressure of more than 2.7 GPa at room temperature and a flash point sufficiently higher than room temperature, and a method for using the pressure medium. DETAILED DESCRIPTION OF THE INVENTION

[0010] The upper and lower limits of the ranges described herein can be combined in any way. For example, when the ranges are "A to B" and "C to D," the ranges "A to D" and "C to B" are also included in the scope of the present invention. Furthermore, unless otherwise specified, the numerical range "lower limit to upper limit" described in this specification means that the range is equal to or greater than the lower limit and equal to or less than the upper limit. In this specification, the numerical values ​​in the examples are numerical values ​​that can be used as upper or lower limit values.

[0011] [Pressure medium type] The pressure medium of this embodiment contains one or more Group 14 element-containing organic compounds (A) selected from the group consisting of compounds (A1) represented by the following general formula (a1) and compounds (A2) represented by the following general formula (a2): [ka] [In the general formula (a1), R a11 , R a12 , R a13 , and R a14 are each independently an alkyl group having 3 to 6 carbon atoms. a1 is a carbon atom or a silicon atom. [ka] [In the general formula (a2), R a21 , R a22 , R a23 , and R a24 are each independently an alkyl group having 3 to 6 carbon atoms. a2 is a silicon atom, a germanium atom, a tin atom, or a lead atom.

[0012] The present inventors have conducted extensive research to solve the above-mentioned problems, and as a result have found that the above-mentioned problems can be solved by using one or more Group 14 element-containing organic compounds (A) (hereinafter also referred to as "component (A)") selected from the group consisting of compounds (A1) represented by the above general formula (a1) and compounds (A2) represented by the above general formula (a2). The reason why the solidification pressure of compound (A1) and compound (A2) is high is not clear, but it is presumed that one of the reasons is that the overlap between the electron orbital of the central atom constituting these compounds and the electron orbital of the alkyl group or alkoxy group surrounding the central atom is appropriately balanced.

[0013] The pressure medium of this embodiment is preferably composed only of component (A), but may contain components other than component (A) as long as the effects of the present invention are not significantly impaired. In the pressure medium of this embodiment, the content of component (A) is preferably 70% by mass to 100% by mass, more preferably 80% by mass to 100% by mass, even more preferably 90% by mass to 100% by mass, still more preferably 95% by mass to 100% by mass, and even more preferably 98% by mass to 100% by mass, based on the total amount of the pressure medium.

[0014] Hereinafter, each component contained in the pressure medium of this embodiment will be described in detail.

[0015] [Component (A)] The pressure medium of this embodiment contains component (A). The component (A) is at least one compound selected from the group consisting of a compound (A1) represented by the above general formula (a1) and a compound (A2) represented by the above general formula (a2). The compound (A1) represented by the general formula (a1) may be used alone or in combination of two or more. The compound (A2) represented by the general formula (a2) may be used singly or in combination of two or more. Here, from the viewpoint of making it easier to increase the solidification pressure at room temperature, component (A) preferably contains compound (A2) represented by general formula (a2) above, and more preferably consists of compound (A2). When component (A) contains compound (A2) represented by general formula (a2) above, the content of compound (A2) is preferably 50% by mass to 100% by mass, more preferably 60% by mass to 100% by mass, even more preferably 70% by mass to 100% by mass, still more preferably 80% by mass to 100% by mass, and even more preferably 90% by mass to 100% by mass, based on the total amount of component (A).

[0016] The compounds (A1) and (A2) will be described in detail below.

[0017] <Compound (A1)> The compound (A1) is a compound represented by the following general formula (a1). [ka]

[0018] In the above general formula (a1), R a11 , R a12 , R a13 , and R a14 are each independently an alkyl group having 3 to 6 carbon atoms. When the number of carbon atoms in the alkyl group is 2 or less, it is difficult to make the flash point sufficiently higher than room temperature. If the alkyl group has seven or more carbon atoms, the solidification pressure will be low. Furthermore, when measuring electrical conductivity under ultra-high pressure, conductive pastes are sometimes used as electrodes. If the alkyl group has seven or more carbon atoms, there is a risk that the conductive paste will dissolve. where R a11 , R a12 , R a13 , and R a14 may be the same alkyl group or different alkyl groups, but from the viewpoint of making it easier to exhibit the effects of the present invention, it is preferable that they are the same alkyl groups. In this specification, the term "same alkyl group" refers to alkyl groups having the same number of carbon atoms and the same structure.

[0019] In addition, from the viewpoint of making it easier to achieve the effects of the present invention (particularly, from the viewpoint of making it easier to increase the solidification pressure), R a11 , R a12 , R a13 , and R a14 The alkyl group that can be selected as the group preferably has 3 to 5 carbon atoms, and more preferably 4 carbon atoms.

[0020] Also, R a11 , R a12 , R a13 , and R a14 The alkyl group that can be selected as may be either linear or branched, but is preferably linear from the viewpoint of making it easier to exhibit the effects of the present invention.

[0021] In the above general formula (a1), Z a1 is a carbon atom or a silicon atom. In order to more easily achieve the effects of the present invention, Z a1 is preferably a silicon atom.

[0022] <Compound (A2)> The compound (A2) is a compound represented by the following general formula (a2). [ka]

[0023] In the above general formula (a2), R a21 , R a22 , R a23 , and R a24 are each independently an alkyl group having 3 to 6 carbon atoms. When the number of carbon atoms in the alkyl group is 2 or less, it is difficult to make the flash point sufficiently higher than room temperature. If the alkyl group has seven or more carbon atoms, the solidification pressure will be low. Furthermore, when measuring electrical conductivity under ultra-high pressure, conductive pastes are sometimes used as electrodes. If the alkyl group has seven or more carbon atoms, there is a risk that the conductive paste will dissolve. where R a21 , R a22 , R a23 , and R a24 may be the same alkyl group or different alkyl groups, but from the viewpoint of making it easier to exhibit the effects of the present invention, it is preferable that they are the same alkyl groups.

[0024] In addition, from the viewpoint of making it easier to achieve the effects of the present invention (particularly, from the viewpoint of making it easier to increase the solidification pressure), R a21 , R a22 , R a23 , and R a24 The alkyl group that can be selected as the group preferably has 3 to 5 carbon atoms, more preferably 3 to 4 carbon atoms, and even more preferably 3 carbon atoms.

[0025] Also, R a21 , R a22 , R a23 , and R a24 The alkyl group that can be selected as may be either linear or branched, but is preferably linear from the viewpoint of making it easier to exhibit the effects of the present invention.

[0026] In the above general formula (a2), Z a2 is a silicon atom, a germanium atom, a tin atom, or a lead atom. From the viewpoint of making it easier to achieve the effects of the present invention (particularly, from the viewpoint of making it easier to increase the solidification pressure), Z a2 is preferably a silicon atom.

[0027] <Ingredients other than ingredient (A)> The pressure medium of this embodiment may or may not contain components other than component (A) as long as the effects of the present invention are not significantly impaired. Examples of the other components include one or more additives selected from antioxidants, corrosion inhibitors, extreme pressure agents, friction modifiers, rust inhibitors, antifoaming agents, and viscosity index improvers. The total content of these additives is preferably 0.01 to 30 mass%, more preferably 0.01 to 20 mass%, even more preferably 0.05 to 15 mass%, and still more preferably 0.1 to 10 mass%, based on the total amount of the pressure medium.

[0028] Furthermore, the pressure medium of this embodiment may contain raw material compounds and by-products generated during the synthesis of component (A) to the extent that the effects of the present invention are not significantly impaired. However, the contents of the raw material compounds and the by-products are preferably small. Specifically, the contents of the raw material compounds and the by-products are each independently preferably 5% by mass or less, more preferably 1% by mass or less, and even more preferably 0.1% by mass or less.

[0029] [Various physical properties of pressure media] <Solidification pressure> The pressure medium of this embodiment has a consolidation pressure at room temperature of more than 2.7 GPa, and the consolidation pressure is preferably more than 3.0 GPa, more preferably more than 3.5 GPa, even more preferably more than 4.1 GPa, still more preferably 4.5 GPa or more, even more preferably 5.0 GPa or more, and even more preferably 5.2 GPa or more. Therefore, the pressure medium of this embodiment can maintain a liquid state even under an ultra-high pressure environment, and can fully fulfill its role as a pressure medium. The upper limit of the solidification pressure of the pressure medium of this embodiment at room temperature is not particularly limited, but is usually less than 6.0 GPa. In this specification, the solidification pressure at room temperature refers to a value measured by the method described in the examples below.

[0030] <Kinematic viscosity at 40°C> In the pressure medium of this embodiment, the kinematic viscosity at 40°C is preferably 1.0 mmHg or less from the viewpoint of suppressing leakage of the pressure medium from the pressure cell when pressure is applied.2 / s, more preferably 1.5 mm 2 / s or more, more preferably 2.0 mm 2 / s or more. Also, normally, 10 mm 2 / s or less. In this specification, the kinematic viscosity at 40°C means a value measured in accordance with JIS K2283:2000.

[0031] <Melting point> In the pressure medium of this embodiment, the melting point is preferably −50° C. or lower, more preferably −60° C. or lower, and even more preferably −70° C. or lower, from the viewpoint of making it a pressure medium that does not solidify even at low temperatures and can be used in low-temperature experiments. The lower limit of the melting point of the pressure medium of this embodiment is not particularly limited, but is usually −100° C. or higher. In this specification, the melting point refers to a value measured by differential scanning calorimetry (hereinafter, sometimes simply referred to as "DSC method").

[0032] <Flash point> In the pressure medium of this embodiment, the flash point is preferably 60° C. or higher, more preferably 65° C. or higher, and even more preferably 70° C. or higher, from the viewpoint of ensuring safety as a temperature sufficiently higher than room temperature. The upper limit of the flash point of the pressure medium of this embodiment is not particularly limited, but is usually 100°C or lower. In this specification, the flash point refers to a value measured by the Pensky-Martens closed-cell method (PM method) in accordance with JIS K2265-3:2007.

[0033] [Use of pressure medium] The pressure medium of this embodiment has a solidification pressure of more than 2.7 GPa at room temperature and a flash point that is sufficiently higher than room temperature. Therefore, the pressure medium of this embodiment is suitable as a pressure medium used in a pressure application system that applies pressure to a substance. Therefore, the pressure medium of this embodiment provides the following methods (1) and (2). (1) A method of using a pressure medium, in which pressure is applied to a substance via the pressure medium of this embodiment. (2) A method for using a pressure medium according to (1) above, wherein the pressure is greater than 2.7 GPa. The above-mentioned method (2) is carried out in a room temperature environment or in a temperature range around the room temperature. However, after applying a predetermined pressure to the substance via the pressure medium, the pressure medium may be cooled while maintaining the pressure, causing the pressure medium to solidify, and the pressure may continue to be applied to the substance.

[0034] As described above, the pressure medium of this embodiment has a solidification pressure at room temperature of preferably more than 3.0 GPa, more preferably more than 3.5 GPa, even more preferably more than 4.1 GPa, still more preferably 4.5 GPa or more, even more preferably 5.0 GPa or more, and even more preferably 5.2 GPa or more. Therefore, for the above embodiment (2), any of these pressure ranges can be adopted.

[0035] [One aspect of the present invention provided] According to one aspect of the present invention, the following [1] to

[11] are provided. [1] A pressure medium comprising one or more Group 14 element-containing organic compounds (A) selected from the group consisting of compounds (A1) represented by the following general formula (a1) and compounds (A2) represented by the following general formula (a2): [ka] [In the general formula (a1), R a11 , R a12 , R a13 , and R a14 are each independently an alkyl group having 3 to 6 carbon atoms. a1 is a carbon atom or a silicon atom. [ka] [In the general formula (a2), R a21 , R a22 , R a23 , and R a24 are each independently an alkyl group having 3 to 6 carbon atoms. a2 is a silicon atom, a germanium atom, a tin atom, or a lead atom. [2] In the general formula (a1), R a11 , R a12 , R a13 , and R a14 are the same alkyl groups. [3] In the general formula (a2), R a21 , R a22 , R a23 , and R a24 are the same alkyl groups. [4] In the general formula (a1), Z a1 The pressure medium according to any one of the above [1] to [3], wherein is a silicon atom. [5] In the general formula (a2), Z a2 The pressure medium according to any one of the above [1] to [4], wherein is a silicon atom. [6] The pressure medium according to any one of the above [1] to [5], which has a solidification pressure of more than 4.1 GPa at 25°C. [7] Kinematic viscosity at 40°C is 1.0mm 2 The pressure medium according to any one of the above [1] to [6], wherein the pressure is more than 1 / s. [8] The pressure medium according to any one of the above [1] to [7], which has a melting point of −50° C. or lower. [9] The pressure medium according to any one of the above [1] to [8], which has a flash point of 70°C or higher.

[10] The pressure medium according to any one of the above [1] to [9], wherein the content of the Group 14 element-containing organic compound (A) is 70 mass % to 100 mass % based on the total amount of the pressure medium.

[11] A method for using a pressure medium, which comprises applying pressure to a substance via the pressure medium according to any one of [1] to

[10] above.

[12] The method of use according to

[11] above, wherein the pressure is greater than 4.1 GPa. [Example]

[0036] The present invention will be specifically described with reference to the following examples, but the present invention is not limited to these examples.

[0037] [Examples 1 to 3, Comparative Examples 1 to 3] The pressure media composed of any of the following compounds were measured or evaluated for the following physical properties (1) to (4).

[0038] Example 1 Tetra-n-propoxysilane In the above general formula (a2), R a21 , R a22 , R a23 , and R a24 are n-propyl groups, and Z a2 is a silicon atom, and the compound corresponds to compound (A2).

[0039] <Example 2> Tetra-n-butoxysilane In the above general formula (a2), R a21 , R a22 , R a23 , and R a24 are n-butyl groups, and Z a2 is a silicon atom, and the compound corresponds to compound (A2).

[0040] Example 3 Tetra-n-butylsilane In the above general formula (a1), R a11 , R a12 , R a13 , and R a14 are n-butyl groups, and Z a1 is a silicon atom, and the compound corresponds to compound (A1).

[0041] <Comparative Example 1> Hexaethyldisiloxane It is a compound represented by the following structural formula. [ka]

[0042] <Comparative Example 2> Tetrakis(trimethylsiloxy)silane It is a compound represented by the following structural formula. [ka]

[0043] <Comparative Example 3> Tetraethoxysilane In the above general formula (a2), R a21 , R a22 , R a23 , and R a24 are compounds in which each is an ethyl group.

[0044] [Methods for measuring or evaluating various physical properties] (1) Kinematic viscosity at 40°C Measurements were made in accordance with JIS K2283:2000. (2) Melting point Measurement was carried out by the DSC method. (3) Flash point Measurement was performed using the Pensky-Martens closed-loop method (PM method) in accordance with JIS K2265-3:2007. (4) Solidification pressure A strain gauge was placed inside a cubic pressure vessel at 25°C and filled with a pressure medium. To apply ultra-high pressure, pressure was applied from six directions to the vessel, and the resistance of the strain gauge was measured. The relationship between pressure and resistance was graphed, and the point where the curve of resistance against pressure bends discontinuously was identified as the solidification pressure point. A strain gauge is a plate-shaped measuring element whose resistance decreases as it is compressed. When the pressure medium remains in a liquid state, the entire element is compressed evenly and shrinks, detecting the compression of the element. However, when pressure is applied to a solidified pressure medium, the strain gauge detects the compression of the solidified pressure medium, increasing its compression rate and causing a sudden decrease in resistance at the solidification pressure point. For this reason, in the graph showing the relationship between pressure and resistance, a point appears where the curve of resistance value versus pressure bends, and this point is identified as the "solidification pressure point." If it is difficult to control the temperature at 25°C, measurements can be taken at two temperatures near 25°C (a temperature below 25°C and a temperature above 25°C) and the solidification pressure at 25°C can be calculated as a linear interpolation value.

[0045] The results are shown in Table 1.

[0046] [Table 1]

[0047] From Table 1, we can see the following: The pressure media of Examples 1 to 3 have high solidification pressures and flash points that are sufficiently higher than room temperature. In contrast, the pressure media of Comparative Examples 1 and 2 have low solidification pressures. The pressure medium of Comparative Example 3 has a low flash point. Regarding the pressure media of Examples 1 to 3 and Comparative Examples 1 to 3, it was confirmed whether or not the conductive paste dissolved. As a result, it was confirmed that the conductive paste did not dissolve in any of them.

Claims

1. A pressure medium comprising one or more Group 14 element-containing organic compounds (A) selected from the group consisting of compounds (A1) represented by the following general formula (a1) and compounds (A2) represented by the following general formula (a2), wherein the content of the Group 14 element-containing organic compounds (A) is 70 mass % to 100 mass % based on the total amount of the pressure medium. 【Chemical Formula 1】 [In the general formula (a1), R ａ１１ , R ａ１２ , R ａ１３ , and R ａ１４ are each independently an alkyl group having 3 to 5 carbon atoms. ａ１ is a silicon atom. 【Chemistry 2】 [In the general formula (a2), R ａ２１ , R ａ２２ , R ａ２３ , and R ａ２４ are each independently an alkyl group having 3 carbon atoms. ａ２ is a silicon atom.

2. In the general formula (a1), R ａ１１ , R ａ１２ , R ａ１３ , and R ａ１４ The pressure medium according to claim 1 , wherein are the same alkyl groups.

3. In the general formula (a2), R ａ２１ , R ａ２２ , R ａ２３ , and R ａ２４ The pressure medium according to claim 1 or 2, wherein each of the alkyl groups is the same.

4. A pressure medium according to claim 1, wherein in the general formula (a1), R a11 , R a12 , R a13 , and R a14 are each independently an alkyl group having 3 to 4 carbon atoms.

5. The pressure medium according to any one of claims 1 to 4, wherein the solidification pressure at 25°C is greater than 4.1 GPa.

6. The kinematic viscosity at 40°C is 1.0 mm ２ The pressure medium according to any one of claims 1 to 5, wherein the pressure is greater than 1 / s.

7. The pressure medium according to any one of claims 1 to 6, having a melting point of -50°C or lower.

8. The pressure medium according to any one of claims 1 to 7, having a flash point of 70°C or higher.

9. A method for applying pressure to a substance via the pressure medium according to any one of claims 1 to 8.

10. 10. The use according to claim 9, wherein the pressure is greater than 4.1 GPa.

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