Composition, dehydrating agent, and dehydration method

Abstract

The present disclosure provides: a composition which contains 1,1,1,3,3,3-hexafluoroisopropyl methyl ether and water; a dehydrating agent which contains the composition; and a method for dehydrating a compound to be treated, the method including a step for distilling 1,1,1,3,3,3-hexafluoroisopropyl methyl ether and water from a composition that contains the compound to be treated, 1,1,1,3,3,3-hexafluoroisopropyl methyl ether, and water.

Description

Composition, dehydrating agent and dehydration method

[0001] The present disclosure relates to compositions, dehydration agents and dehydration methods.

[0002] There are various methods known for removing water from compounds and compositions. Classical dehydration methods include the use of dehydrating agents such as calcium chloride and magnesium sulfate, and regenerable molecular sieves, but each method has many problems, such as the tendency to generate waste.

[0003] On the other hand, various compounds that form azeotropic compositions with water are known, and dehydration methods utilizing the azeotropic phenomenon of such compounds with water are also known. For example, Patent Document 1 discloses a dehydration method in which an organic solvent that forms an azeotropic composition with water, such as benzene or toluene, is used to perform azeotropic distillation of benzene / water or toluene / water to distill water out of the system.

[0004] Japanese Patent Application Publication No. 02-122803

[0005] The dehydration method using the azeotropic reaction of benzene / water or toluene / water described in Patent Document 1 has a problem in that, according to "Chemical Handbook: Basic Edition" (Revised Third Edition, p. II-144, Maruzen Co., Ltd., 1984), the boiling points of the azeotropic compositions are as high as 69°C and 85°C, respectively, and therefore the amount of heat required for distillation is large.

[0006] From the perspective of reducing the amount of heat, it is conceivable to use a compound with a lower boiling point in an azeotropic composition with water instead of benzene or toluene. For example, according to the Basic Chemistry Handbook (Revised 3rd Edition, p. II-144, Maruzen Co., Ltd., 1984), methylene chloride has a low boiling point of 38°C in an azeotropic composition with water, and therefore it is presumed that the amount of heat required for azeotropy can be reduced. However, since the water content in the methylene chloride / water azeotropic composition is low at 1.5% by mass, it is presumed that a long time is required to distill off a certain amount of water, making this method difficult to say efficient. Furthermore, since reflux is required during this time, it is conceivable that the amount of heat required for distillation will also increase as a result.

[0007] The present disclosure aims to provide a composition containing 1,1,1,3,3,3-hexafluoroisopropyl methyl ether and water, which can be used as a dehydrating agent. The present disclosure also aims to provide a dehydrating agent containing the composition. The present disclosure also aims to provide a dehydration method that enables efficient dehydration with a low amount of heat.

[0008] As a result of extensive research, the present inventors have found that by distilling a composition containing a compound to be treated, 1,1,1,3,3,3-hexafluoroisopropyl methyl ether, and water, water can be distilled off together with 1,1,1,3,3,3-hexafluoroisopropyl methyl ether. That is, it has been found that 1,1,1,3,3,3-hexafluoroisopropyl methyl ether and water contained in the composition act as dehydrating agents. Furthermore, the inventors have found that the amount of heat required during distillation is small, enabling efficient dehydration, and have thus completed the present invention.

[0009] That is, it has been found that the above problems can be solved by the following configuration.

[0010] [1] A composition containing 1,1,1,3,3,3-hexafluoroisopropyl methyl ether and water. [2] The composition according to [1], wherein the content of the water is 50% by mass or less relative to the total amount of the 1,1,1,3,3,3-hexafluoroisopropyl methyl ether and the water. [3] The composition according to [1] or [2], wherein the mass ratio of the 1,1,1,3,3,3-hexafluoroisopropyl methyl ether to the water is 78:22 to 79:21. [4] The composition according to any one of [1] to [3], wherein the composition contains a compound to be treated. [5] The composition according to [4], wherein the compound to be treated and the 1,1,1,3,3,3-hexafluoroisopropyl methyl ether are different compounds. [6] The composition according to [5], wherein the boiling point of the compound to be treated is higher than the azeotropic point of the 1,1,1,3,3,3-hexafluoroisopropyl methyl ether and water. [7] The composition according to [4], wherein the compound to be treated and the 1,1,1,3,3,3-hexafluoroisopropyl methyl ether are the same compound. [8] A method for dehydrating the compound to be treated, comprising a step of distilling the 1,1,1,3,3,3-hexafluoroisopropyl methyl ether and the water from a composition containing the compound to be treated, 1,1,1,3,3,3-hexafluoroisopropyl methyl ether, and water. [9] The dehydration method according to [8], wherein the compound to be treated and the 1,1,1,3,3,3-hexafluoroisopropyl methyl ether are different compounds.

[10] The dehydration method according to [9], wherein the boiling point of the compound to be treated is higher than the azeotropic point of the 1,1,1,3,3,3-hexafluoroisopropyl methyl ether and water.

[11] The dehydration method according to [8], wherein the compound to be treated and the 1,1,1,3,3,3-hexafluoroisopropyl methyl ether are the same compound.

[12] An agent for dehydrating a compound to be treated by distillation, comprising the composition according to any one of [1] to [3].

[13] A dehydrating agent for removing water adhering to the surface of a solid object to be treated from the surface, the dehydrating agent comprising the composition according to any one of [1] to [3].

[14] A method for dehydrating an object to be treated, comprising the steps of: preparing a treatment liquid containing 1,1,1,3,3,3-hexafluoroisopropyl methyl ether (Step A); preparing a solid object to be treated having water adhered thereto (Step B); and contacting the object to be treated with the treatment liquid to form the composition described in any one of [1] to [3] in the treatment liquid (Step C).

[15] A method for dehydrating an object to be treated, comprising the steps of: preparing a treatment liquid containing the composition described in any one of [1] to [3] (Step D); preparing a solid object to be treated having water adhered thereto (Step B); and contacting the object to be treated with the treatment liquid to increase the water content in the treatment liquid (Step C1).

[16] The method for dehydrating an object to be treated according to

[15] , wherein the treatment liquid obtained in Step C1 is used as the treatment liquid in Step D.

[17] The dehydration method for an object to be treated according to

[15] , further comprising a step of reducing the water content of the treatment liquid obtained in the step C1.

[0011] According to the present disclosure, there is provided a composition containing 1,1,1,3,3,3-hexafluoroisopropyl methyl ether and water, which can be used as a dehydrating agent. The present disclosure also provides a dehydrating agent containing the composition. The present disclosure also provides a dehydration method that enables efficient dehydration with a low amount of heat.

[0012] In this specification, a numerical range expressed using "to" means a range that includes the numerical values ​​before and after "to" as the lower and upper limits. In this specification, the boiling points, azeotropic points, and azeotropic compositions described refer to the boiling points, azeotropic points, and azeotropic compositions at normal pressure (101.3 kPa).

[0013] [Composition] The composition of the present disclosure contains 1,1,1,3,3,3-hexafluoroisopropyl methyl ether (hereinafter also referred to as HFE-356mmz) and water. Hereinafter, in this specification, reference to "the composition of the present disclosure" refers to a composition containing HFE-356mmz and water, unless otherwise specified.

[0014] As described above, the present inventors have found that by distilling a composition containing the compound to be treated, 1,1,1,3,3,3-hexafluoroisopropyl methyl ether, and water, water is distilled off together with HFE-356mmz, and that the amount of heat required during distillation is small and dehydration can be achieved efficiently. Furthermore, through further investigation, the present inventors have confirmed that when the mass ratio of HFE-356mmz to water is 78:22 to 79:21, an azeotropic composition of HFE-356mmz / water or an azeotrope-like composition is obtained, and that the azeotropic point is 48°C. Since the azeotropic composition of HFE-356mmz / water has a relatively low azeotropic point of 48°C, the amount of heat required for distillation can be reduced. Furthermore, because the water content in the azeotropic composition is high, dehydration does not require a long time, and water can be removed efficiently. The present inventors speculate that the occurrence of an azeotropic phenomenon of HFE-356mmz / water during distillation of a composition containing the compound to be treated, 1,1,1,3,3,3-hexafluoroisopropyl methyl ether, and water may enable efficient dehydration with a low heat quantity. Note that the term "azeotrope-like composition" refers to a composition that is not a thermodynamically strict azeotropic composition, but whose liquid composition is substantially equal to the composition of the gas in equilibrium.

[0015] The composition of the present disclosure may contain HFE-356mmz and water. For example, a composition containing a compound to be treated, HFE-356mmz, and water is also included in the composition of the present disclosure. Hereinafter, a composition containing a compound to be treated, HFE-356mmz, and water will also be referred to as a composition of the present disclosure containing a compound to be treated. Note that the composition of the present disclosure is not limited to homogeneous solution-type compositions, but also includes two-layer compositions that cause layer separation.

[0016] In the composition of the present disclosure, the mass ratio of HFE-356mmz to water is not particularly limited, but the mass ratio of 1,1,1,3,3,3-hexafluoroisopropyl methyl ether to water is preferably 50.000:50.000 to 99.999:0.001. In a preferred embodiment, the content of the water is preferably 50% by mass or less, more preferably 22% by mass or less, more preferably 20% by mass or less, and more preferably 15% by mass or less, relative to the total amount of the 1,1,1,3,3,3-hexafluoroisopropyl methyl ether and the water. The content of the water is preferably 0.001% by mass or more, more preferably 0.003% by mass or more, and more preferably 0.01% by mass or more, relative to the total amount of the 1,1,1,3,3,3-hexafluoroisopropyl methyl ether and the water.

[0017] In a preferred embodiment, the mass ratio of HFE-356mmz to water in the composition of the present disclosure is not particularly limited, but is preferably 50:50 to 99:1, more preferably 78:22 to 99:1, and even more preferably 78:22 to 79:21. In another preferred embodiment, the mass ratio of HFE-356mmz to water in the composition of the present disclosure is not particularly limited, but is preferably 50:50 to 99:1, more preferably 78:22 to 99:1, even more preferably 80:20 to 99:1, and particularly preferably 85:15 to 99:1. In a composition of the present disclosure containing a compound to be treated, when the mass ratio of HFE-356mmz to water is within the above range, water in the composition can be efficiently distilled off by HFE-356mmz.

[0018] The composition of the present disclosure may contain a compound to be treated. The compound to be treated is preferably a compound to be dehydrated.

[0019] The composition of the present disclosure can be used as a dehydrating agent. In a preferred embodiment, the composition of the present disclosure is a composition to be treated in a dehydration treatment.

[0020] In a composition according to the present disclosure containing a compound to be treated, one preferred embodiment is one in which the compound to be treated and HFE-356mmz are different compounds. Examples of compounds to be treated that are different from HFE-356mmz include organic compounds and salts of organic compounds. Specific examples of organic compounds and salts of organic compounds include aromatic ethers, aliphatic ethers, aromatic esters, aliphatic esters (e.g., ethyl acetate (boiling point 77°C)), aromatic amines, aliphatic compounds, aromatic amine salts, aliphatic amine salts, aromatic nitriles, aliphatic nitriles, aromatic carboxylic acids, aliphatic carboxylic acids, aromatic carboxylic acid salts, aliphatic carboxylic acid salts, aromatic sulfonic acids, aliphatic sulfonic acids, aromatic sulfonates, aliphatic sulfonates, aromatic nitro compounds, aliphatic nitro compounds, aromatic alcohols, aliphatic alcohols, aromatic aldehydes, aliphatic aldehydes, alkanes, alkenes, alkynes, halogenated alkanes, halogenated alkenes, halogenated alkynes, amino acids, amino acid salts, heterocyclic compounds, and salts of heterocyclic compounds. In one preferred embodiment, the compound to be treated is preferably an organic compound. In a preferred embodiment, the organic compound is an aliphatic ester.

[0021] When the compound to be treated is a compound other than HFE-356mmz, it is more preferable that the boiling point of the compound to be treated is higher than the azeotropic point of HFE-356mmz and water. When the boiling point of the compound to be treated is higher than the azeotropic point of HFE-356mmz and water, it becomes easier to separate the HFE-356mmz and water in the composition of the present disclosure containing the compound to be treated from the compound to be treated by distillation. The boiling point of the compound to be treated is more preferably 5°C or higher, and even more preferably 20°C or higher, than the azeotropic point of HFE-356mmz and water (48°C).

[0022] It is also preferable that the compound to be treated other than HFE-356mmz is a compound that forms an azeotropic composition with water. When the compound to be treated is a compound that forms an azeotropic composition with water, a composition containing the compound to be treated and water cannot be obtained by normal distillation with a water content lower than that in the azeotropic composition. By adding HFE-356mmz to this to form a composition containing the compound to be treated, HFE-356mmz, and water, the water can be distilled off together with HFE-356mmz, and a composition can be obtained with a water content lower than that in the azeotropic composition of the compound to be treated and water.

[0023] The content of the compound to be treated that is different from HFE-356mmz in the composition of the present disclosure containing the compound to be treated is not particularly limited, but may be, for example, a concentration range obtained by adding HFE-356mmz to a composition containing the compound to be treated and water, i.e., a compound whose water content is to be reduced (which may be a hydrous compound), so that the mass ratio of HFE-356mmz to water falls within the above-mentioned preferred range. For example, the content of the compound to be treated that is different from HFE-356mmz in the composition of the present disclosure containing the compound to be treated may be 1% by mass to 99% by mass, preferably 5% by mass to 95% by mass, and more preferably 10% by mass to 90% by mass.

[0024] In another preferred embodiment of the composition of the present disclosure containing a compound to be treated, the compound to be treated and HFE-356mmz are the same compound. In this case, the mass ratio of HFE-356mmz to water may be within the preferred range described above, preferably 70.000:30.000 to 99.999:0.001, and more preferably 90.000:10.000 to 99.997:0.003. Since the saturated water content of the compound to be treated, HFE-356mmz, at 25°C and 101.3 kPa is approximately 800 ppm by mass, the composition may have a water content of 800 ppm by mass or less relative to HFE-356mmz.

[0025] [Dehydrating Agent] One aspect of the present disclosure also relates to an agent for dehydrating a compound to be treated by distillation, the agent comprising a composition containing HFE-356mmz and water. The agent is a so-called dehydrating agent for the compound to be treated. The composition containing 356mmz and water is the "composition of the present disclosure" described above. The compound to be treated is the same as the compound to be treated in the composition of the present disclosure, and the preferred range is also the same.

[0026] [Dehydration Method] One embodiment of the dehydration method of the present disclosure is a dehydration method using distillation, which includes a step of distilling HFE-356mmz and water from a composition containing the compound to be treated, HFE-356mmz, and water. Hereinafter, in this specification, reference to the "dehydration method of the present disclosure" refers to the above-mentioned dehydration method, unless otherwise specified.

[0027] When distillation is performed using the dehydration method of the present disclosure, either a batch or continuous distillation method can be used. Hereinafter, each step of the dehydration method of the present disclosure will be described using the example of batch distillation. The batch distillation apparatus used can be a general batch distillation apparatus equipped with a distillation column having a reflux condenser at the top of the column and a heating device in the kettle section.

[0028] <Two-Phase Separation Step (1)> In the composition containing the compound to be treated, HFE-356mmz, and water used in the dehydration method of the present disclosure, or the composition containing the compound to be treated and water constituting the composition, or the composition containing HFE-356mmz and water constituting the composition, if the water content is equal to or greater than a certain level, an interface is formed and layer separation occurs. In such cases, it is also preferable to carry out a step of performing two-layer separation on the composition containing at least one of the compound to be treated and HFE-356mmz, and water, and removing the water layer, before carrying out the heating step or distillation step described below. The layer separation can be carried out using a separation tank or a separation membrane.

[0029] <Heating Step> In one preferred embodiment of the dehydration method of the present disclosure, a heating step is provided in which a composition containing the compound to be treated, HFE-356mmz, and water is heated. In other words, a preferred embodiment of the dehydration method of the present disclosure is a method for dehydrating the compound to be treated, comprising the steps of: heating a composition containing the compound to be treated, HFE-356mmz, and water; and distilling the HFE-356mmz and the water from the composition. The detailed description of the compound to be treated in the composition containing the compound to be treated, HFE-356mmz, and water, and the amounts of each component, can be found in the above description of [Composition].

[0030] That is, in the dehydration method of the present disclosure, one preferred embodiment is one in which the compound to be treated and HFE-356mmz are different compounds. When the compound to be treated is a compound other than HFE-356mmz, it is more preferable that the boiling point of the compound to be treated is higher than the azeotropic point of HFE-356mmz and water. Another preferred embodiment is one in which the compound to be treated and HFE-356mmz are the same compound in the dehydration method of the present disclosure.

[0031] Heating can be carried out by charging a composition containing the compound to be treated, HFE-356mmz, and water into the kettle section of a distillation column and heating the kettle section. Regarding the heating temperature when heating a composition containing the compound to be treated, HFE-356mmz, and water, from the viewpoint of separating the compound to be treated from the water, it is necessary to heat the liquid in the kettle section of the distillation column so that the liquid temperature is higher than the azeotropic point (48°C) of the azeotropic composition of HFE-356mmz / water and lower than the boiling point of the compound to be treated. Furthermore, from the viewpoint of separating the compound to be treated from HFE-356mmz, it is preferable to heat the liquid to a temperature higher than the boiling point of HFE-356mmz (51°C) and lower than the boiling point of the compound to be treated, and more preferably to a temperature about 10°C higher than the temperature at which the mixture in the kettle begins to boil. However, when the compound to be treated is the same compound as HFE-356mmz, it is preferable to heat the liquid in the kettle to a temperature of 52 to 65° C., more preferably 53 to 60° C. The heating time (reflux time) is preferably 1 minute to 4 hours, more preferably 5 minutes to 1 hour.

[0032] It should be noted that the heating step is not essential in the dehydration method of the present disclosure. Another embodiment of the distillation step in the dehydration method of the present disclosure is to carry out the distillation step under reduced pressure, i.e., to carry out vacuum distillation. When vacuum distillation is carried out, heating may or may not be carried out, but it is sufficient to charge a composition containing the compound to be treated, HFE-356mmz, and water into the kettle section of a distillation column and proceed to the distillation step.

[0033] (Preparation of Composition) The method for preparing a composition containing a compound to be treated, HFE-356mmz, and water is not particularly limited. The composition can be obtained by appropriately mixing the compound to be treated, HFE-356mmz, and water. The order of the components when mixing is not limited. When the compound to be treated and HFE-356mmz are the same compound, the composition can be prepared, for example, as follows. In a preferred embodiment, the composition can be prepared by adding HFE-356mmz and water to HFE-356mmz as the compound to be treated. HFE-356mmz containing water may be used as a raw material for the compound to be treated. The compound to be treated in the above composition represents HFE-356mmz. In another preferred embodiment, the composition can be prepared by adding HFE-356mmz to HFE-356mmz containing water. The added HFE-356mmz may contain water. Furthermore, the HFE-356mmz to be added may be substantially free of water, or may even be free of water. Substantially free of water means that the water content relative to HFE-356mmz is less than 10 ppm by mass.

[0034] <Distillation Step> With regard to the step of distilling HFE-356mmz and water from a composition (distillation step) in the dehydration method of the present invention, the case where distillation is performed without reducing pressure will be described below, taking as an example the case where the distillation step is performed using a composition that has been subjected to the heating step described above. The fraction containing HFE-356mmz and water can be removed from the top of the distillation column, for example, by maintaining the heating temperature in the heating step, or by operating the reflux vessel with a distillation / reflux ratio of 1000:1 to 1:10.

[0035] By using the above-mentioned dehydration method, a composition containing concentrated water and HFE-356mmz is obtained as a fraction, and a composition containing the compound to be treated (which may be the compound to be treated itself) with a reduced water content is obtained in the pot section of the distillation column. When the compound to be treated and HFE-356mmz are the same compound, HFE-356mmz that is substantially free of water can be obtained in the pot section of the distillation column. Here, "substantially free of water" means that the water content relative to HFE-356mmz is less than 10 ppm by mass.

[0036] The batch distillation apparatus used may incorporate a method for removing other components such as impurities contained in the composition charged in the pot section of the distillation column. For example, the apparatus may be designed to use multiple reflux condensers provided at the top of the distillation column in a switchable manner, from the viewpoint of removing impurities that may be contained in the composition containing HFE-356mmz and water to be distilled, or may be designed to further include a distillation column for impurity removal, from the viewpoint of removing impurities that may be contained in the composition containing the compound to be treated that remains in the pot section of the distillation column.

[0037] A continuous distillation method may be employed. As the continuous distillation apparatus, a general continuous distillation apparatus equipped with a distillation column having a reflux condenser at the top of the column and a heating device in the kettle section may be used. When a continuous distillation method is employed, a composition containing the compound to be treated, HFE-356mmz, and water is continuously introduced into the middle of the distillation column, and while heating the kettle section of the distillation column, water and HFE-356mmz are distilled from the top of the distillation column, and a composition containing the compound to be treated (which may be the compound to be treated itself) with a reduced water content is intermittently or continuously distilled from the kettle section of the distillation column. In this case, the heating temperature is preferably 3°C to 30°C higher than the azeotropic point (48°C) of HFE-356mmz and water, more preferably 5°C to 10°C higher.

[0038] The continuous distillation apparatus may incorporate a method for removing other components such as impurities contained in the composition introduced from the middle stage of the distillation column, and may, for example, be configured to combine a distillation column for removing impurities with a distillation column for dehydration.

[0039] <Two-Phase Separation Step (2)> In addition, when distilled using the dehydration method of the present disclosure, the composition of concentrated water and HFE-356mmz obtained by distillation forms an interface at room temperature and undergoes layer separation if the water content in the fraction is equal to or greater than a certain level. Therefore, HFE-356mmz having a saturated water content can be recovered using a separation tank or separation membrane. That is, the dehydration method of the present disclosure may include a step of performing two-phase separation on the composition consisting of HFE-356mmz and water distilled in the distillation step and removing the water layer. It is also preferable to perform two-phase separation on the initial fraction distilled in the distillation step and remove the water layer. One preferred embodiment of the dehydration method of the present disclosure includes at least one of the two-phase separation steps (1) and (2) described above. It is also preferable to include both the two-phase separation step (1) and the two-phase separation step (2). HFE-356mmz having a saturated water content obtained by two-phase separation can be reused in the dehydration method of the present disclosure. When the compound to be treated and HFE-356mmz are different compounds, HFE-356mmz having a saturated water content can be used as a dehydrating agent to obtain a compound to be treated with a reduced water content. When the compound to be treated and HFE-356mmz are the same compound, HFE-356mmz having a saturated water content can be used again in the dehydration method of the present disclosure to obtain HFE-356mmz that is substantially free of water. Here, when a continuous distillation method is employed and the compound to be treated and HFE-356mmz are the same compound, that is, when the water in aqueous HFE-356mmz is dehydrated using a continuous distillation apparatus by the dehydration method of the present disclosure to obtain dehydrated HFE-356mmz, the HFE-356mmz having a saturated water content obtained from the fraction can be introduced again into the continuous distillation apparatus as aqueous HFE-356mmz and used as a raw material to obtain dehydrated HFE-356mmz, which is preferable because it allows for the construction of a dehydration process in which no HFE-356mmz is discarded.

[0040] [Dehydrating Agent for Solid Objects to be Treated] The dehydrating agent of the present disclosure may alternatively be a dehydrating agent that removes water adhering to the surface of a solid object to be treated from the surface. The dehydrating agent for solid objects to be treated of the present disclosure is a dehydrating agent comprising a composition containing 1,1,1,3,3,3-hexafluoroisopropyl methyl ether and water. In a preferred embodiment, the water content is preferably 50% by mass or less relative to the total amount of the 1,1,1,3,3,3-hexafluoroisopropyl methyl ether and the water. The water content is preferably 20% by mass or less, more preferably 10% by mass or less, even more preferably 5% by mass or less, and particularly preferably 3% by mass or less. The lower limit is preferably 0.001% by mass or more, more preferably 0.003% by mass or more, and particularly preferably 0.01% by mass or more. Examples of solid objects to be treated include those described below.

[0041] [Method for dehydrating solid object to be treated] The method for dehydrating solid object to be treated according to the present disclosure is a method for dehydrating an object to be treated, comprising the steps of: preparing a treatment liquid containing 1,1,1,3,3,3-hexafluoroisopropyl methyl ether (Step A); preparing a solid object to be treated having water attached thereto (Step B); and contacting the treatment liquid with the object to be treated to form a composition according to the present disclosure in the treatment liquid (Step C). Hereinafter, in this specification, reference to the "method for dehydrating solid object to be treated according to the present disclosure" refers to the above-described dehydration method, unless otherwise specified.

[0042] Another embodiment of the method for dehydrating an object to be treated according to the present disclosure is a method for dehydrating an object to be treated, comprising: a step (Step D) of preparing a treatment liquid containing a composition containing 1,1,1,3,3,3-hexafluoroisopropyl methyl ether and water; a step (Step B) of preparing a solid object to be treated having water attached thereto; and a step (Step C1) of contacting the object to be treated with the treatment liquid to increase the water content in the treatment liquid.

[0043] <Step A> Step A is a step of preparing a treatment liquid containing 1,1,1,3,3,3-hexafluoroisopropyl methyl ether. The treatment liquid may be, for example, HFE-356mmz substantially free of water, or may be a composition of the present disclosure containing HFE-356mmz and water. The content of 1,1,1,3,3,3-hexafluoroisopropyl methyl ether in the treatment liquid is not particularly limited, but is preferably 10 to 99.9% by mass relative to the total mass of the treatment liquid. In one preferred embodiment, the content of water in the treatment liquid is preferably 20% by mass or less, more preferably 10% by mass or less, even more preferably 5% by mass or less, particularly preferably 3% by mass or less, and most preferably 1% by mass or less, relative to the total amount of 1,1,1,3,3,3-hexafluoroisopropyl methyl ether and water. The lower limit is not particularly limited, but may be 0.001% by mass or more, 0.003% by mass or more, or 0.01% by mass or more.

[0044] <Step B> Step B is a step of preparing a solid object to be treated having water attached thereto. The solid object to be treated having water attached thereto is not particularly limited. Examples of the solid object to be treated include bulk materials such as glass substrates, silicon substrates, optical components including lenses and prisms, components constituting liquid crystal display devices and organic EL display devices, electronic components, metal components, and precision machine components. The amount of water attached to the object to be treated is not particularly limited.

[0045] <Step C> Step C is a step of contacting the object to be treated with a treatment liquid containing 1,1,1,3,3,3-hexafluoroisopropyl methyl ether to form a composition containing 1,1,1,3,3,3-hexafluoroisopropyl methyl ether and water in the treatment liquid. The content of 1,1,1,3,3,3-hexafluoroisopropyl methyl ether in the treatment liquid prepared in step A is not particularly limited, but is preferably 10 to 99.9 mass% based on the total mass of the treatment liquid. The conditions for the contact step are not particularly limited.

[0046] The method of contacting the treatment liquid with the object to be treated is not particularly limited. When the treatment liquid is separated into two layers, an organic layer containing HFE-356mmz and an aqueous layer, for example, the treatment liquid may be gently brought into contact with the surface of the object to be treated so that the upper aqueous layer does not come into contact with the object to be treated and so that the two layers do not mix. Alternatively, the organic layer and the aqueous layer may be vigorously stirred to bring the treatment liquid into a pseudo-homogeneous state, and then the treatment liquid may be brought into contact with the surface of the object to be treated.

[0047] The contact time between the treatment solution and the object to be treated is preferably 10 minutes or more, more preferably 30 minutes or more, even more preferably 60 minutes or more, and particularly preferably 90 minutes or more. The upper limit of the contact time is not particularly limited, but from the viewpoint of treatment efficiency, 600 minutes or less is preferable. By step C, water adhering to the object to be treated can be removed.

[0048] The composition of the present disclosure is produced by step C. As described above, the composition of the present disclosure is a composition containing 1,1,1,3,3,3-hexafluoroisopropyl methyl ether and water. Details are the same as those described above for the composition of the present disclosure, and preferred ranges are also the same. In a preferred embodiment, the content of the water is preferably 50 mass% or less with respect to the total amount of the 1,1,1,3,3,3-hexafluoroisopropyl methyl ether and the water. In another preferred embodiment, the mass ratio of the 1,1,1,3,3,3-hexafluoroisopropyl methyl ether to the water is preferably 78:22 to 79:21. In another preferred embodiment, the mass ratio of the 1,1,1,3,3,3-hexafluoroisopropyl methyl ether to the water is preferably 80:20 to 99: 1, more preferably 85:15 to 99: 1, even more preferably 90:10 to 99: 1, and particularly preferably 95:5 to 99: 1. When producing the composition of the present disclosure, it is preferable to appropriately adjust the contents of 1,1,1,3,3,3-hexafluoroisopropyl methyl ether and water contained in the composition in Step A and Step B.

[0049] The treatment liquid obtained in step C can be used as the treatment liquid in step A. By recycling in this way, the amount of 1,1,1,3,3,3-hexafluoroisopropyl methyl ether used in the dehydration method (so-called draining washing) of the solid treatment object can be reduced.

[0050] The treated liquid obtained in step C is preferably purified before being recycled as the treated liquid in step A. The purification method is not particularly limited, but examples thereof include adsorption dehydration using molecular sieves, dehydration by distillation, etc. In one embodiment, the distillation method described above can be used. Purification is preferred because it can reduce the water content of the treated liquid obtained in step C.

[0051] Before the treatment liquid obtained in step C is recycled as the treatment liquid in step A (recycled), the water concentration in the treatment liquid may be reduced. The method for reducing the water concentration is not particularly limited, but, for example, when the treatment liquid is separated into an organic layer containing HFE-356mmz and an aqueous layer, the aqueous layer may be removed. The water concentration in the treatment liquid may be reduced by adding HFE-356mmz that is substantially free of water or has a low water content.

[0052] Furthermore, the composition of the present disclosure, which is the treatment liquid obtained in step C, can also be used in the dehydration method of the present disclosure. When the treatment liquid obtained in step C is used in the dehydration method of the present disclosure, a similar water concentration reduction treatment may be carried out.

[0053] <Step D> Step D is a step of preparing a treatment liquid containing a composition containing 1,1,1,3,3,3-hexafluoroisopropyl methyl ether and water. The composition containing 1,1,1,3,3,3-hexafluoroisopropyl methyl ether and water is the composition of the present disclosure. Details are the same as those described above for the composition of the present disclosure, and the preferred ranges are also the same. Furthermore, a preferred embodiment can be the embodiment of Step C above. Furthermore, in another preferred embodiment, the content of water in the treatment liquid is preferably 20% by mass or less, more preferably 10% by mass or less, even more preferably 5% by mass or less, particularly preferably 3% by mass or less, and most preferably 1% by mass or less, relative to the total amount of 1,1,1,3,3,3-hexafluoroisopropyl methyl ether and water. The lower limit is not particularly limited, but may be 0.001% by mass or more, 0.003% by mass or more, or 0.01% by mass or more.

[0054] <Step C1> Step C1 is a step of contacting the treatment liquid with the object to be treated to increase the water content in the treatment liquid. Step C1 makes it possible to remove water adhering to the object to be treated. In step C1, the water content in the treatment liquid is increased.

[0055] The method and time for contacting the treatment liquid with the object to be treated are preferably the same as those described in step C.

[0056] The treatment liquid obtained in the step C1 can be used as the treatment liquid in the step D. By recycling in this way, the amount of 1,1,1,3,3,3-hexafluoroisopropyl methyl ether used in the dehydration method (so-called draining washing) of the solid treatment object can be reduced.

[0057] It is preferable to purify the treated liquid obtained in step C1 before recycling it as the treated liquid in step D. The purification method is not particularly limited, but examples include adsorption dehydration using molecular sieves, dehydration by distillation, etc. In one embodiment, the above-mentioned distillation method can be used. Purification is preferable because it can reduce the water content of the treated liquid obtained in step C1.

[0058] Before the treatment liquid obtained in step C1 is used as the treatment liquid in step D (recycled), the water concentration in the treatment liquid may be reduced, for example, by the method described in step C.

[0059] Furthermore, the composition of the present disclosure, which is the treatment liquid obtained in step C1, can also be used in the dehydration method of the present disclosure. When the treatment liquid obtained in step C1 is used in the dehydration method of the present disclosure, a similar water concentration reduction treatment may be performed.

[0060] The composition of the present invention can also be used in step A. By using the composition of the present invention in step A, water can be removed even though the composition contains water.

[0061] The present disclosure will be described in more detail below with reference to examples, but the present disclosure is not limited thereto.

[0062] [Example 1] (Batch distillation apparatus) A reflux condenser was installed at the top of the column. 569.81 g of HFE-356mmz having a water content of 610.0 ppm was added to the kettle of a 500 mL distillation column with a theoretical number of 25 plates packed with Helipak No. 2 (manufactured by Tohtokenji Co., Ltd.), and the kettle was heated in a 62.0 ° C. oil bath. The refrigerant temperature in the reflux condenser was set to 5 ° C., the pressure was set to 104.0 kPa, and reflux was started. 60 minutes after the start of reflux, the reflux condenser was operated at a distillation and reflux ratio of 1 second: 30 seconds, and the fraction was taken out from the top of the column. The pressure of the reflux condenser was 103.9 kPa. After 15 minutes, the reflux condenser was stopped, and the fraction was weighed to be 55.01 g. 55 g of dehydrated methanol was added to this and homogenized, and the moisture content was measured using a Karl Fischer moisture analyzer, which was found to be 2,600 ppm. Furthermore, the HFE-356mmz remaining in the kettle was weighed to be 478.00 g, and its moisture content was <1.0 ppm by mass. The results are summarized in Table 1.

[0063]

[0064] [Example 2] (Batch distillation apparatus) A 500 mL distillation column with a theoretical number of 25 plates packed with Helipak No. 2 (manufactured by Tohtokenji Co., Ltd.) having a reflux condenser at the top of the column, was charged with 135.01 g of ethyl acetate and 16.5 g of water to prepare a simulated liquid. Subsequently, 135.2 g of HFE-356 mmmz was added and heated in a 76.8 ° C. oil bath. The refrigerant temperature in the reflux condenser was set to 10 ° C., the pressure was set to 101.4 kPa, and reflux was started. 60 minutes after the start of reflux, the reflux condenser was operated at a reflux ratio of 1 second:60 seconds, and the fraction was taken out from the top of the column. The pressure of the reflux condenser was 101.5 kPa. Since the temperature of the condenser rises when the fraction is removed, the temperature of the oil bath was adjusted to about +10 ° C. above the boiling point temperature of the condenser in order to prevent the reflux from being interrupted. After 120 minutes, the reflux condenser was stopped and the fraction separated into two layers was separated and weighed using a separatory funnel. 16.00 g of water was recovered as the upper layer, and 105.19 g of HFE-356mmz was recovered as the lower layer. The purity of the recovered HFE-356mmz was measured by gas chromatography (GC) and was found to be 100%. Furthermore, the composition containing ethyl acetate remaining in the vessel was weighed to be 135 g, and the purity of the ethyl acetate was measured by gas chromatography and was found to be 99.21%, with a water content of 60 ppm by mass. The results are summarized in Table 2. Hereinafter, 356mmz in the table refers to HFE-356mmz.

[0065]

[0066] In Example 1, even when the "continuous distillation method" was used, the amount of water in the pot portion of the distillation column could be reduced, as in Example 1.

[0067] Example 3 (Dehydration Experiment) A 700 ml three-necked round flask was fitted with a Dean-Stark apparatus and a glass reflux condenser attached to the top. Subsequently, an aluminum test piece (3 mm x 15 mm x 30 mm) was weighed as the workpiece (object to be treated), and the dry workpiece weight was 3.5253 g. Next, the workpiece was washed with water and weighed, and the weight was 3.5619 g, confirming that 0.0366 g of water had adhered. The wetted workpiece was placed in a round flask, and 650 g of dried 1,1,1,3,3,3-hexafluoroisopropyl methyl ether was added. The round flask was then heated in a 60 °C oil bath to initiate reflux. After the start of reflux, heating was stopped after 2 hours and the workpiece was allowed to cool. After another hour, the workpiece was removed and weighed, yielding a value of 3.5254 g. The weight of the workpiece after the dehydration operation was the same as the weight of the workpiece before water adhesion, indicating that the adhered water had been removed.

[0068] Example 4 (Dehydration Experiment) A 700 ml three-necked round flask was fitted with a Dean-Stark apparatus and a glass reflux condenser attached to its top. Subsequently, an aluminum test piece (3 mm x 15 mm x 30 mm) was weighed as the workpiece, and the dry workpiece weight was 3.4606 g. Next, the workpiece was washed with water and weighed, and it was confirmed that the weight of the workpiece was 3.4964 g and that 0.0358 g of water had adhered. The wetted workpiece was placed in a round flask, and 650 g of dried 1,1,1,3,3,3-hexafluoroisopropyl methyl ether was added, followed by the addition of 6.5 g of water, resulting in an HFE-356mmz / water composition with a water content of 1% by mass. Next, the round flask was heated in a 60 ° C oil bath to initiate reflux. After the start of reflux, heating was stopped after 2 hours and the workpiece was cooled. After another hour, the workpiece was removed and weighed, which was 3.4607 g. The weight of the workpiece after the dehydration operation was the same as the weight of the workpiece before the water was attached, which indicated that the attached water had been removed.

[0069]

[0070] Examples 5 to 7 (Dehydration Experiments) Dehydration was carried out under the same conditions as in Example 4, except that the amount of water added to the round flask was changed. Table 4 shows the water content in the HFE-356mmz / water composition and the effect of water removal.

[0071] The effectiveness of water removal was evaluated based on the following index: Amount of water adhering after dehydration / weight of dried workpiece x 100 (%) was calculated and evaluated as follows: A: The amount of water adhering to the workpiece after dehydration is less than 0.01% B: The amount of water adhering to the workpiece after dehydration is 0.01% or more and less than 0.1% C: The amount of water adhering to the workpiece after dehydration is 0.1% or more and less than 1% D: The amount of water adhering to the workpiece after dehydration is 1% or more and less than 3%

[0072]

[0073] Examples 4-1 to 4-5 (Dehydration Experiments) After the start of reflux, the elapsed time was changed so that heating was stopped after a predetermined time, followed by cooling for 1 hour and removing the workpiece. Except for this, dehydration was carried out under the same conditions as in Example 4. Table 5 shows the elapsed time and the effect of water removal. Note that Example 4-5 corresponds to Example 4 above.

[0074] The effectiveness of water removal was evaluated based on the following index: Amount of water adhering after dehydration / weight of dried workpiece x 100 (%) was calculated and evaluated as follows: A: The amount of water adhering to the workpiece after dehydration is less than 0.01% B: The amount of water adhering to the workpiece after dehydration is 0.01% or more and less than 0.1% C: The amount of water adhering to the workpiece after dehydration is 0.1% or more and less than 1% D: The amount of water adhering to the workpiece after dehydration is 1% or more and less than 3%

[0075]

[0076] According to the present disclosure, there is provided a composition containing 1,1,1,3,3,3-hexafluoroisopropyl methyl ether and water, which can be used as a dehydrating agent. The present disclosure also provides a dehydrating agent containing the composition. The present disclosure also provides a dehydration method that enables efficient dehydration with a low amount of heat.

[0077] Although the present disclosure has been described in detail and with reference to specific embodiments, it will be apparent to those skilled in the art that various changes and modifications can be made without departing from the spirit and scope of the present disclosure. This application is based on Japanese patent applications filed on August 21, 2023 (Patent Application No. 2023-134122) and November 27, 2023 (Patent Application No. 2023-199892), the contents of which are incorporated herein by reference.

Claims

1. A composition containing 1,1,1,3,3,3-hexafluoroisopropyl methyl ether and water.

2. The composition according to claim 1, wherein the content of the water is 50 mass% or less based on the total amount of the 1,1,1,3,3,3-hexafluoroisopropyl methyl ether and the water.

3. The composition according to claim 1, wherein the mass ratio of the 1,1,1,3,3,3-hexafluoroisopropyl methyl ether to the water is from 78:22 to 79:

21.

4. The composition according to claim 1, which contains a compound to be treated.

5. The composition according to claim 4, wherein the compound to be treated and the 1,1,1,3,3,3-hexafluoroisopropyl methyl ether are different compounds.

6. The composition according to claim 5, wherein the boiling point of the compound to be treated is higher than the azeotropic point of the 1,1,1,3,3,3-hexafluoroisopropyl methyl ether and water.

7. The composition according to claim 4, wherein the compound to be treated and the 1,1,1,3,3,3-hexafluoroisopropyl methyl ether are the same compound.

8. A method for dehydrating a compound to be treated, comprising the step of distilling off 1,1,1,3,3,3-hexafluoroisopropyl methyl ether and water from a composition containing the compound to be treated, 1,1,1,3,3,3-hexafluoroisopropyl methyl ether, and water.

9. The dehydration method according to claim 8, wherein the compound to be treated and the 1,1,1,3,3,3-hexafluoroisopropyl methyl ether are different compounds.

10. The dehydration method according to claim 9, wherein the boiling point of the compound to be treated is higher than the azeotropic point of the 1,1,1,3,3,3-hexafluoroisopropyl methyl ether and water.

11. The dehydration method according to claim 8, wherein the compound to be treated and the 1,1,1,3,3,3-hexafluoroisopropyl methyl ether are the same compound.

12. An agent for dehydrating a compound to be treated by distillation, comprising the composition according to any one of claims 1 to 3.

13. A dehydrating agent for removing water adhering to the surface of a solid object to be treated from said surface, said dehydrating agent comprising the composition according to any one of claims 1 to 3.

14. A method for dehydrating an object to be treated, comprising the steps of: preparing a treatment liquid containing 1,1,1,3,3,3-hexafluoroisopropyl methyl ether (Step A); preparing a solid object to be treated having water attached thereto (Step B); and contacting the object to be treated with the treatment liquid to form a composition according to any one of claims 1 to 3 in the treatment liquid (Step C).

15. A method for removing water from an object to be treated, comprising the steps of: preparing a treatment liquid containing the composition according to any one of claims 1 to 3 (step D); preparing a solid object to be treated having water adhering thereto (step B); and contacting the object to be treated with the treatment liquid to increase the water content in the treatment liquid (step C1).

16. A method for removing water from an object to be treated according to claim 15, wherein the treatment liquid obtained in step C1 is used as the treatment liquid in step D.

17. A method for dehydrating an object to be treated according to claim 15, further comprising a step of reducing the water content of the treatment liquid obtained in step C1.

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