JP2016065229A - Non-flammable liquid composition containing phosphate ester, phosphate ester amid or phosphate amide and fluorine-containing phosphate ester - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a liquid having non-flammable high fire retardancy, high donor property and excellent compatibility to an organic compound and salt, further an efficient metallic salt extraction method with high safety, a nonaqueous electrolyte with high safety and high conductivity and a nonaqueous secondary battery containing the same.SOLUTION: There is provided a liquid composition containing phosphate ester, phosphate ester amide or phosphate amide and fluorine-containing phosphate ester represented by the formula (2), the fluorine-containing phosphate ester has lower melting point than that of phosphate ester, phosphate ester amide or phosphate amide and weight percentage of 10 to 90% of whole liquid composition, and the liquid composition has no flash point.SELECTED DRAWING: None

Description

  The present invention relates to a phosphoric acid ester, a phosphoric acid ester amide or a non-flammable liquid composition comprising phosphoric acid amide and a fluorine-containing phosphoric acid ester, and uses of the liquid composition.

  Conventionally, chlorinated solvents such as carbon tetrachloride, 1,1,1-trichloroethane, chloroform, and dichloromethane have been used in large quantities as solvents that are nonflammable and excellent in compatibility with organic compounds. However, carbon tetrachloride and 1,1,1-trichloroethane have been discontinued since 1996 in developed countries because they are substances involved in ozone layer destruction. The use of chloroform and dichloromethane is also restricted due to toxicity concerns such as carcinogenicity (Non-patent Document 1), and an alternative solvent that is safe and excellent in compatibility with organic compounds is required.

  Under such circumstances, phosphate esters such as phosphate esters and phosphate ester amides have flame retardancy derived from phosphorus atoms and donor properties derived from phosphorus-oxygen double bond sites. Because of excellent compatibility with compounds, flame retardants for resins and non-aqueous electrolytes (Patent Documents 1 to 3, Non-Patent Document 2), hydraulic oil (Patent Document 4), metal extractant (Patent Document 5, Non-Patent Document) Document 3), organic synthesis solvents (Non-patent Document 4), polymerization solvents (Patent Document 6) and the like are used in various applications.

  However, liquid phosphoric esters are all flammable liquids having a flash point, and sufficient care is required when handling them. Particularly in recent years, flame retardant applications have become diversified and sophisticated. For example, when used as an extraction solvent for spent nuclear fuel treatment, many safety measures have been taken so as not to cause an accident such as a fire or explosion, and there is a demand for incombustibility of the solvent. Even when used as a hydraulic fluid for aircraft, a material with particularly high safety such as having a high flash point is required (Patent Document 4). Furthermore, as non-aqueous electrolytes for non-aqueous secondary batteries, non-flammable electrolytes that do not ignite or explode in the gas phase when the electrolyte leaks have been studied (Patent Document 7). ). Conventional phosphate esters are not sufficient for such a demand.

  On the other hand, it is known that a fluorine-containing phosphate ester in which a part of the ester side chain is substituted with a fluorine atom has high flame retardancy due to a synergistic effect of the phosphorus atom and the fluorine atom (Patent Document 8). .

  However, in the case of a fluorine-containing phosphate ester, the donor property of the phosphate ester site is lowered due to the electron withdrawing property of fluorine atoms. For this reason, compatibility with organic compounds and salts may not be sufficient, and it has not been used in applications that require high donor properties such as metal extractants. Further, the fluorine-containing phosphate ester does not have sufficient performance as a non-aqueous electrolyte solvent, such as the solubility of the electrolyte salt and the low conductivity of the electrolyte when dissolved.

Japanese Patent Laid-Open No. 54-19919 JP-A-11-181428 JP-A-11-260401 JP 2008-519146 A JP 2001-192746 A JP-A-52-141895 JP 2013-20713 A JP 2007-258067 A

2013 Review Committee Report on Health Measures for Preventing Workers' Health Injuries Caused by Chemical Substances (Ministry of Health, Labor and Welfare) J. et al. Fire Recipient Chemistry, 5,86 (1078) Zhurnal Analicheskoi Kimii, 24, 1386 (1969). J. et al. Am. Chem. Soc. , 127, 15453 (2005)

  The present invention has been made in view of these problems. That is, an object of the present invention is to provide a liquid composition having high non-flammability, high flame retardancy, high donor properties and excellent compatibility with organic compounds and salts. It is another object of the present invention to provide a safe and efficient metal salt extraction method, a non-aqueous electrolyte with high safety and high conductivity, and a non-aqueous secondary battery containing the same.

  As a result of intensive studies to solve the above-mentioned problems, the present inventors incorporated a phosphoric ester having a specific structure and a specific physical property into a phosphoric ester having a specific structure, phosphoric ester amide or phosphoric amide. Thus, it was found that a liquid composition having high non-flammability, high flame retardancy, high donor properties and excellent compatibility with organic compounds and salts can be obtained. Furthermore, it has been found that a safe and efficient metal salt extraction method using this as a solvent, a non-aqueous electrolyte with high safety and high conductivity, and a non-aqueous secondary battery containing the same are provided. The present invention has been completed. That is, the present invention relates to the following gist.

1. The following general formula (1)

(In the formula, n represents an integer of 0 to ^3. R ¹ , R ² and R ³ are each independently a linear or branched alkyl group having 1 to 10 carbon atoms, an alkenyl group or 6 to 10 carbon atoms. Represents an aryl group, and R ² and R ³ may be bonded to each other to form a 5- to 8-membered cyclic structure.
The phosphoric acid ester, phosphoric acid ester amide or phosphoric acid amide represented by the following general formula (2)

(In the formula, m represents an integer of 1 to 3. Rf represents a linear or branched fluorine-containing alkyl group having 1 to 10 carbon atoms, and R ⁴ represents a linear or branched carbon group having 1 to 10 carbon atoms. Represents an alkyl group, an alkenyl group or an aryl group having 6 to 10 carbon atoms, provided that the ratio of the number of fluorine atoms to the number of hydrogen atoms in the whole molecule is 0.2 or more.)
The fluorine-containing phosphoric acid ester represented by the general formula (2) is a liquid composition comprising the phosphoric acid ester, the phosphoric acid ester amide or the phosphoric acid amide represented by the general formula (1). And the weight fraction of the fluorine-containing phosphate ester of the general formula (2) is 10 to 90% of the entire liquid composition, and the liquid composition has no flash point. A non-flammable liquid composition.

  2. 2. The non-flammable liquid composition according to item 1, wherein the weight fraction of the fluorine-containing phosphate ester of the general formula (2) is 30 to 70% of the entire liquid composition.

3. ^3. The non-flammable according to item 1 or 2, wherein in general formula (1), R ¹ , R ² and R ³ are each independently a linear or branched alkyl group having 1 to 4 carbon atoms. Liquid composition.

  4). The non-flammable liquid composition according to any one of items 1 to 3, wherein n is 0 in the general formula (1).

  5. 4. The non-flammable liquid composition according to any one of items 1 to 3, wherein in the general formula (1), n is 1.

6). In the general formula (2), R ⁴ is a linear or branched alkyl group having 1 to ⁴ carbon atoms, and Rf is a linear or branched fluorine-containing alkyl group having 1 to 3 carbon atoms, The non-flammable liquid composition according to any one of 1 to 5 above.

  7). The non-flammable liquid composition according to any one of items 1 to 6, wherein m is 2 in the general formula (2).

8). The nonflammable liquid composition according to any one of items 1 to 6, wherein m is 3 in the general formula (2).

  A metal extraction method comprising extracting a metal component from an aqueous solution containing metal ions using the non-flammable liquid composition according to any one of items 9.1 to 8 as an extraction solvent.

  A non-aqueous secondary battery comprising: a solvent containing the non-flammable liquid composition according to any one of items 10.1 to 8; and a lithium salt dissolved in the solvent. Non-aqueous electrolyte for use.

  11. 11. The non-aqueous electrolyte for a non-aqueous secondary battery according to 10, wherein the solvent further contains a cyclic carbonate.

  12. A non-aqueous secondary battery comprising the non-aqueous electrolyte according to item 10 or 11.

  According to the present invention, non-flammable highly flame retardant, donor by blending a phosphoric acid ester having a specific structure, a phosphoric acid ester amide or a phosphoric acid amide with a fluorine-containing phosphoric acid ester having a specific structure and specific properties. A liquid composition having high compatibility and excellent compatibility with organic compounds and salts can be obtained. Furthermore, a safe and efficient metal salt extraction method using this as a solvent, a non-aqueous electrolyte solution having high safety and high conductivity, and a non-aqueous secondary battery containing the same are provided.

It is a schematic cross section which shows the lithium ion secondary battery of the coin-type cell used by the Example and the comparative example.

  The non-flammable liquid composition of the present embodiment is a phosphoric acid ester of the above general formula (1), a phosphoric acid ester amide or a mixture of phosphoric acid amide and the above-mentioned fluorine-containing phosphoric acid ester of the general formula (2). The fluorine-containing phosphoric acid ester of the general formula (2) has a lower boiling point than the phosphoric acid ester, phosphoric acid ester amide or phosphoric acid amide of the general formula (1), and the fluorine-containing phosphoric acid of the general formula (2) It is a liquid containing 10 to 90% by weight of ester with respect to the entire liquid composition. In this invention, a liquid composition is a composition which exhibits a liquid state at normal temperature or under heating, and the temperature in the case of heating is 20-100 degreeC normally. The phosphoric acid ester of the above general formula (1), phosphoric acid ester amide or phosphoric acid amide and the above-mentioned fluorine-containing phosphoric acid ester of general formula (2) are very compatible with each other, and a liquid in which they are mixed The composition exhibits a high degree of non-flammable safety. Although this mechanism is not clear, it is considered that the suffocation effect by the fluorine-containing compound gasified at the time of combustion of the liquid composition and the decomposition product stop the combustion chain. In addition, the non-flammable liquid composition of the present embodiment has a high donor property and excellent compatibility with the organic compound and the salt, so that a metal extraction solvent, a non-aqueous electrolyte solvent, a cleaning agent, etc. Excellent performance in each application.

(Phosphate ester, phosphate ester amide or phosphate amide)
In the above general formula (1), n represents an integer of 0 to 3. When n is 0, it is a phosphate ester having only an ester group in the side chain. When n is 1 or 2, it is a phosphate ester amide having an ester group and an amide group in the side chain, and n is 3. Is a phosphoric acid amide having only an amide group in the side chain.

R ¹ , R ² and R ³ each independently represent a linear or branched alkyl group having 1 to 10 carbon atoms, an alkenyl group or an aryl group having 6 to 10 carbon atoms, and R ² and R ³ are bonded to each other. A 5- to 8-membered ring structure may be formed. R ¹ , R ² and R ³ may each be substituted with a substituent such as a hydroxy group, an alkoxy group, an ester group, a ketone group, an amino group, an amide group, a thiol group or a thioalkoxy group.

Examples of R ¹ , R ² and R ³ are methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, t-butyl group, n-pentyl group, neopentyl group, n-hexyl. Group, n-heptyl group, n-octyl group, 2-ethylhexyl group, n-nonyl group, n-decyl group, vinyl group, allyl group, 3-butenyl group, 5-hexenyl group, phenyl group, 2-methylphenyl Group, 3-methylphenyl group, 4-methylphenyl group, 2,6-dimethylphenyl group, 2,4,6-trimethylphenyl group, 4-ethylphenyl group, 4-hexylphenyl group, 4-octylphenyl group, A naphthyl group etc. can be mentioned.

As examples of the phosphoric acid ester or phosphoric acid ester amide of the general formula (1), the phosphoric acid ester of n = 0 includes trimethyl phosphate, triethyl phosphate, tri-n-propyl phosphate, triisopropyl phosphate, phosphoric acid Triallyl, tri-n-butyl phosphate, triisobutyl phosphate, tri-t-butyl phosphate, tri-n-hexyl phosphate, triphenyl phosphate, tri-n-octyl phosphate, tris phosphate (2- Ethyl hexyl), tri-n-decyl phosphate, and the like.
As phosphoric ester amides with n = 1, phosphoric acid dimethyldimethylamide, phosphoric acid dimethyldiethylamide, phosphoric acid dimethyldi-n-propylamide, phosphoric acid dimethyldiisopropylamide, phosphoric acid dimethyldi-n-butylamide, phosphoric acid dimethyldiisobutyramide , Dimethyldi-t-butylamide phosphate, dimethyldi-n-pentylamide phosphate, dimethyldineomentylamide phosphate, dimethyldi-n-hexylamide phosphate, dimethyldiphenylamide phosphate, dimethyldi-n-octylamide phosphate, Dimethylbis (2-ethylhexyl) amide phosphate, dimethyldi-n-decylamide phosphate, dimethyl-N-methylethylphosphate phosphate, dimethyl-N-methyl-n-propylamide phosphate, dimethyl-N-methylisopropyl acetate Luamide, phosphoric acid dimethyl-N-methylallylamide, phosphoric acid dimethyl-N-methyl-n-butyramide, phosphoric acid dimethyl-N-methylisobutyramide, phosphoric acid dimethyl-N-methyl-t-butylamide, phosphoric acid dimethyl- N-methyl-n-hexylamide, dimethyl phosphate-N-methylphenylamide, dimethyl phosphate-N-methyl-n-octylamide, dimethyl phosphate-N-methyl (2-ethylhexyl) amide, dimethyl phosphate- N-methyl-n-decylamide, phosphoric acid diethyldimethylamide, phosphoric acid di-n-propyldimethylamide, phosphoric acid diisopropyldimethylamide, phosphoric acid di-n-butyldimethylamide, phosphoric acid diisobutyldimethylamide, phosphoric acid di- t-Butyldimethylamide, di-n-hexyl dimethyl methacrylate Amide, di-n-octyldimethylamide phosphate, bis (2-ethylhexyl) dimethylamide phosphate, di-n-decyldimethylamide phosphate, dimethylpyrrolidide phosphate, dimethylpiperidide phosphate, dimethylheptate phosphate Methyleneimide, dimethyloctamethyleneimide phosphate, dimethyl phosphate (2-methylpiperidide), dimethyl phosphate (3-methylpiperidide), dimethyl phosphate (4-methylpiperidide), dimethyl phosphate (2,6-dimethylpiperidide) And dimethyl phosphate (2,2,6,6-tetramethylpiperidide).
Examples of phosphoric ester amides with n = 2 include bis (dimethylamido) methyl phosphate, bis (diethylamido) methyl phosphate, bis (di-n-propylamido) methyl phosphate, bis (diisopropylamido) methyl phosphate, Bis (diallylamido) methyl phosphate, bis (di-n-butylamido) methyl phosphate, bis (diisobutylamido) methyl phosphate, bis (di-t-butylamido) methyl phosphate, bis (di-n-phosphate) Pentylamide) methyl, bis (dinepentylamide) methyl phosphate, bis (di-n-hexylamide) methyl phosphate, bis (diphenylamide) methyl phosphate, bis (di-n-octylamide) methyl phosphate Bis [bis (2-ethylhexyl) amido] methyl phosphate, bis (di-n-decylamido) methyl phosphate, Bis (N-methylethylamido) methyl phosphate, bis (N-methyl-n-propylamido) methyl phosphate, bis (N-methylisopropylamido) methyl phosphate, bis (N-methylallylamido) methyl phosphate, Bis (N-methyl-n-butyramide) methyl phosphate, bis (N-methylisobutyramide) methyl phosphate, bis (N-methyl-t-butyramide) methyl phosphate, bis (N-methyl-n-phosphate) Hexylamido) methyl, bis (N-methylphenylamido) methyl phosphate, bis (N-methyl-n-octylamido) methyl phosphate, bis [N-methyl (2-ethylhexyl) amido] methyl phosphate, phosphoric acid Bis (N-methyl-n-decylamido) methyl, bis (dimethylamido) ethyl phosphate, bis (dimethylamido) phosphate-n- Propyl, bis (dimethylamide) isopropyl phosphate, bis (dimethylamide) -n-butyl phosphate, bis (dimethylamide) isobutyl phosphate, bis (dimethylamide) -t-butyl phosphate, bis (dimethylamide phosphate) ) -N-hexyl, bis (dimethylamide) -n-octyl phosphate, bis (dimethylamido) -2-ethylhexyl phosphate, bis (dimethylamido) -n-decyl phosphate, dipyrrolidide methyl phosphate, phosphorus Dipiperididomethyl phosphate, diheptamethyleneimidomethyl phosphate, dioctamethyleneimidomethyl phosphate, bis (2-methylpiperidide) methyl phosphate, bis (3-methylpiperidide) methyl phosphate, bis (4-methylpiperidide phosphate) ) Methyl, bis (2,6-dimethylpiperidide) methyl phosphate, bis (2 , 2,6,6-tetramethylpiperidido) methyl and the like. Examples of phosphoric amides with n = 3 include hexamethyl phosphoric triamide, hexaethyl phosphoric triamide, hexa-n-butyl phosphoric triamide, hexa-n-hexyl phosphoric triamide, hexa-n-octyl phosphoric triamide and the like. Can be mentioned.

Among these phosphate esters, phosphate ester amides or phosphate amides, in particular, R ¹ , R ² and R ³ in the general formula (1) are each independently a linear or branched alkyl group having 1 to 4 carbon atoms. However, it is easy to obtain good performance in each application such as a metal extraction solvent and a non-aqueous electrolyte solvent. In addition, in the case of the phosphoric acid ester or phosphoric acid ester amide in which n = 0 or n = 1 in the general formula (1), good performance is easily obtained in each application such as a metal extraction solvent and a non-aqueous electrolyte solvent. In particular, when the liquid composition of the present embodiment is used as a non-aqueous electrolyte solvent for a non-aqueous secondary battery having a high potential exceeding 4.2 V with respect to Li / Li ⁺ , phosphoric acid of n = 0 It is desirable to use an ester. In addition, when the non-flammable liquid composition of the present embodiment is used as a metal extraction solvent, particularly high extraction efficiency is obtained when n = 1 phosphoric ester amide is used.

(Fluorine-containing phosphate ester)
In the above general formula (2), m is an integer of 1 to 3. R ⁴ represents a linear or branched alkyl group having 1 to 10 carbon atoms, an alkenyl group, or an aryl group having 6 to 10 carbon atoms. R ⁴ may be substituted with a substituent such as a hydroxy group, an alkoxy group, an ester group, a ketone group, an amino group, an amide group, a thiol group, or a thioalkoxy group. Rf represents a linear or branched fluorine-containing alkyl group having 1 to 10 carbon atoms.

Examples of R ⁴ include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, t-butyl group, n-pentyl group, neopentyl group, n-hexyl group, n-heptyl group. N-octyl group, 2-ethylhexyl group, n-nonyl group, n-decyl group, vinyl group, allyl group, 3-butenyl group, 5-hexenyl group, phenyl group, 2-methylphenyl group, 3-methylphenyl Groups, 4-methylphenyl group, 2,6-dimethylphenyl group, 2,4,6-trimethylphenyl group, 4-ethylphenyl group, 4-hexylphenyl group, 4-octylphenyl group, naphthyl group, etc. Can do.

  Examples of Rf include trifluoromethyl group, 2,2-difluoroethyl group, 2,2,2-trifluoroethyl group, 2,2,3,3-tetrafluoropropyl group, 2,2,3,3, 3-pentafluoropropyl group, hexafluoroisopropyl group, 2,2,3,3,4,4,5,5-octafluoropentyl group, 2,2,3,3,4,4,5,5,5 -Nonafluoropentyl group, 3,3,4,4,5,5,6,6,6-nonafluorohexyl group, 2,2,3,3,4,4,5,5,6,6,7 , 7-dodecafluoroheptyl group, 2,2,3,3,4,4,5,5,6,6,7,7,8,8,9,9-hexadecafluorononyl group, 3,3, 4,4,5,5,6,6,7,7,8,8,9,9,10,10,10-heptadedecyl group etc. Can.

  Here, the fluorine-containing phosphate ester according to the present embodiment has a ratio of the number of fluorine atoms to the number of hydrogen atoms as a whole molecule of 0.2 or more (F / H ≧ 0.2) and These have a boiling point lower than that of the phosphoric acid ester, phosphoric acid ester amide or phosphoric acid amide represented by the general formula (1). When the ratio of the number of fluorine atoms to the number of hydrogen atoms is less than 0.2, or when the boiling point is higher than that of phosphate ester, phosphate ester amide or phosphate amide, it is highly non-flammable in the resulting liquid composition. It is difficult to obtain safety.

Examples of such fluorine-containing phosphate esters include, when m = 1, dimethyltrifluoromethyl phosphate, dimethyl-2,2-difluoroethyl phosphate, dimethyl-2,2,2-trifluorophosphate. Ethyl, dimethyl-2,2,3,3-tetrafluoropropyl phosphate, dimethyl-2,2,3,3,3-pentafluoropropyl phosphate, dimethylhexafluoroisopropyl phosphate, dimethyl-2,2 phosphate , 3,3,4,4,5,5-octafluoropentyl, dimethyl-2,2,3,3,4,4,5,5,5-nonafluoropentyl phosphate, dimethyl-3,3 phosphate , 4,4,5,5,6,6,6-nonafluorohexyl, dimethyl-2,2,3,3,4,4,5,5,6,6,7,7-dodecafluoroheptyl phosphate , Dimethyl phosphate 2,2,3,3,4,5,5,6,6,7,7,8,8,9,9-hexadecafluorononyl, dimethyl-3,3,4,4,5 phosphate 5, 6, 6, 7, 7, 8, 8, 9, 9, 10, 10, 10-heptadedecyl, diethyl-2,2,2-trifluoroethyl phosphate, and the like.
When m = 2, bis (trifluoromethyl) methyl phosphate, bis (2,2-difluoroethyl) methyl phosphate, bis (2,2,2-trifluoroethyl) methyl phosphate, bis ( 2,2,3,3-tetrafluoropropyl) methyl, bis (2,2,3,3,3-pentafluoropropyl) methyl phosphate, bis (hexafluoroisopropyl) methyl phosphate, bis (2, 2,3,3,4,4,5,5-octafluoropentyl) methyl, bis (2,2,3,3,4,4,5,5,5-nonafluoropentyl) methyl phosphate, phosphoric acid Bis (3,3,4,4,5,5,6,6,6-nonafluorohexyl) methyl, bis (2,2,3,3,4,4,5,5,6,6, phosphate) 7,7-dodecafluoroheptyl) methyl, bis (2, , 3,3,4,4,5,5,6,6,7,7,8,8,9,9-hexadecafluorononyl) methyl, bis (3,3,4,4,5, phosphate) 5,6,6,7,7,8,8,9,9,10,10,10-heptadecadecyl) methyl, bis (2,2,2-trifluoroethyl) ethyl phosphate, bis (2, 2,2-trifluoroethyl) -n-propyl, bis (2,2,2-trifluoroethyl) isopropyl phosphate, bis (2,2,2-trifluoroethyl) allyl phosphate, bis (2 , 2,2-trifluoroethyl) -n-butyl, bis (2,2,2-trifluoroethyl) isobutyl phosphate, bis (2,2,2-trifluoroethyl) -t-butyl phosphate, phosphorus Acid bis (2,2,2-trifluoroethyl) -n-hexyl, phosphoric acid (2,2,2-trifluoroethyl) -n-octyl, bis (2,2,2-trifluoroethyl) phosphate-n-decyl phosphate, bis (2,2,2-trifluoroethyl) phosphate Phenyl, bis (2,2,2-trifluoroethyl) phosphate 4-methylphenyl, bis (2,2,2-trifluoroethyl) phosphate-2,4,6-trimethylphenyl phosphate, bis (2 , 2,2-trifluoroethyl) naphthyl and the like.
In the case of m = 3, tris phosphate (trifluoromethyl), tris phosphate (2,2-difluoroethyl), tris phosphate (2,2,2-trifluoroethyl), tris phosphate (2,2 , 3,3-tetrafluoropropyl), tris phosphate (2,2,3,3,3-pentafluoropropyl), tris phosphate (hexafluoroisopropyl), tris phosphate (2,2,3,3) 4,4,5,5-octafluoropentyl), tris phosphate (2,2,3,3,4,4,5,5,5-nonafluoropentyl), tris phosphate (3,3,4,4) 4,5,5,6,6,6-nonafluorohexyl), tris phosphate (2,2,3,3,4,4,5,5,6,6,7,7-dodecafluoroheptyl), Tris phosphate (2,2,3,3,4,4,5,5,6,6,7 7,8,8,9,9-hexadecafluorononyl), tris phosphate (3,3,4,4,5,5,6,6,7,7,8,8,9,9,10, 10,10-heptadedecyl and the like can be mentioned.
Among these fluorine-containing phosphates, R ⁴ in the general formula (2) is a linear or branched alkyl group having 1 to ⁴ carbon atoms, and Rf is a linear or branched alkyl group having 1 to 3 carbon atoms. When it is a fluorine-containing alkyl group, good performance is easily obtained in each application such as a metal extraction solvent and a non-aqueous electrolyte solvent. In particular, in the case of a fluorine-containing phosphate ester in which m = 2 or m = 3 in the general formula (2), good performance is easily obtained in each application such as a metal extraction solvent and a non-aqueous electrolyte solvent.

(mixing ratio)
The liquid composition of the present embodiment is a mixture of the phosphoric acid ester of the general formula (1), the phosphoric acid ester amide or the phosphoric acid amide and the fluorine-containing phosphoric acid ester of the general formula (2). The weight fraction of the fluorine-containing phosphate ester of the general formula (2) is 10% to 90% of the entire liquid composition. When the weight fraction of the fluorine-containing phosphate is less than 10% of the entire liquid composition, the effect of eliminating the flash point may not be sufficient. Further, when the weight fraction of the fluorine-containing phosphate ester exceeds 90%, the donor property is not sufficiently high, and the metal extraction ability and the compatibility of salts and organic compounds may not be sufficient. Moreover, since metal extraction capability can further be improved, it is more preferable that the weight fraction of the fluorine-containing phosphate ester of General formula (2) is 30%-70% of the whole liquid composition.

(Metal extraction solvent)
The liquid composition of the present embodiment has a high safety such as non-flammability, and has a feature that the number of donors is high and the compatibility of the organic compound and the salt is excellent. Therefore, the metal extraction solvent, the non-aqueous electrolyte solvent It can be used in various applications such as cleaning agents, organic synthesis solvents, polymerization solvents, hydraulic oils and the like.

  Among these applications, as an example that can be particularly suitably used, an extraction solvent for extracting a metal component from an aqueous solution containing metal ions can be given. By using the non-flammable liquid composition of the present embodiment as a solvent, not only high safety can be obtained, but also surprisingly very excellent performance is exhibited as a metal extraction ability.

  Examples of the metal species that can be extracted using the non-flammable liquid composition of the present embodiment as a solvent include metals of Groups 3 to 16 in the periodic table. In particular, extraction of Group 10 metals such as Pt and Pd, Group 9 elements such as Co and Ir, and Group 3 metals such as Y, Gd, U, and Pu is effective in terms of element selectivity. Specific examples of metal extraction include recovery of Pt and Ir from treatment liquid obtained in non-ferrous metal refining processes, recovery of uranium from spent nuclear fuel, purification of various other metals such as rare earth metals, etc. be able to.

  The aqueous solution containing the above metal ions used for extraction can be acidic, neutral, or basic liquid, but it is particularly desirable to use a liquid acidified with a mineral acid such as hydrochloric acid, nitric acid or sulfuric acid. . Although the density | concentration of the metal ion in this aqueous solution is not specifically limited, Usually, it is 1 ppm-50000 ppm. Moreover, although the usage-amount of the nonflammable liquid composition of this embodiment with respect to this aqueous solution is not specifically limited, Usually, it is 0.1-10 times amount by weight ratio.

  The extraction method is not particularly limited, and any method such as a batch method or a continuous method using countercurrent contact can be used. After extraction, the metal component extracted into the non-flammable liquid composition of the present embodiment can be recovered by a known back extraction method or the like.

(Nonaqueous electrolyte solvent for nonaqueous secondary batteries)
Since the liquid composition of the present embodiment is non-flammable, it is excellent in safety and has a high donor number and excellent salt solubility, so that it can be used as a non-aqueous electrolyte solvent for a non-aqueous secondary battery. It can be suitably used. Here, the non-aqueous secondary battery according to the present embodiment is a generic term for a lithium ion secondary battery and a lithium secondary battery.

As the electrolyte salt dissolved in the non-aqueous electrolyte, a lithium salt that is stable in a wide potential region used in a non-aqueous secondary battery can be used. For example, LiBF ₄ , LiPF ₆ , LiClO ₄ , LiCF ₃ SO ₃ , Examples include LiN (FSO ₂ ) ₂ , LiN (CF ₃ SO ₂ ) ₂ , LiN (C ₂ F ₅ SO ₂ ) ₂ , LiC (CF ₃ SO ₂ ) _{3 and the} like. The concentration of the electrolyte salt in the nonaqueous electrolytic solution is in the range of 0.5 to 2.5 mol / L, preferably 1.0 to 2.0 mol / L, in order to improve the high rate charge / discharge characteristics of the battery. It is desirable to do. By using the non-flammable liquid composition of the present embodiment as a solvent, the electrolyte salt can be dissolved at such a high concentration and high electrical conductivity can be obtained while ensuring high safety of the non-aqueous electrolyte. Is possible. When a film forming agent such as vinylene carbonate, fluoroethylene carbonate, propane sultone or the like is added to the non-aqueous electrolyte, the capacity retention rate is high, and good battery performance is easily obtained.
In addition to the non-flammable liquid composition of the present embodiment, as a non-aqueous electrolyte solvent, cyclic carbonates such as ethylene carbonate, propylene carbonate and butylene carbonate, cyclic esters such as γ-butyrolactone, cyclic sulfones such as sulfolane, etc. A solvent may be used in combination. By using these in combination, it is possible to obtain a non-aqueous secondary battery in which the electrical conductivity of the non-aqueous electrolyte is further improved and characteristics such as high rate charge / discharge characteristics are improved. As the solvent used in combination, a cyclic carbonate is particularly preferable in terms of battery performance. In addition, as for the usage-amount of cyclic carbonate etc. with respect to the nonflammable liquid composition of this embodiment, it is desirable to make it 0.1 to 4 times by weight ratio. By setting the amount of cyclic carbonate or the like to be 4 times or less, it is possible to obtain a non-aqueous electrolyte and a non-aqueous secondary battery having no flash point and higher safety.

The non-aqueous secondary battery according to the present embodiment uses the non-aqueous electrolyte and includes at least a positive electrode, a negative electrode, and a separator. As the positive electrode material, typically, LiCoO ₂ , LiNiO ₂ , LiMnO ₂ , LiMn ₂ O ₄ , LiNi _1/3 Co _1/3 Mn _1/3 O ₂ , LiNi _1/4 Mn _3/4 O ₂ , LiFeO ₂ , A composite oxide composed of lithium and a transition metal such as LiFePO ₄ can be used.

  As the negative electrode material, use lithium metal, lithium alloy for lithium secondary batteries, and carbon materials that can be doped / undoped with lithium ions, and complex oxides such as lithium titanate for lithium ion secondary batteries. Can do. In particular, when hard carbon and lithium titanate are used as the negative electrode material, the capacity retention rate is high, and good battery performance is easily obtained.

  As the separator, a microporous membrane or the like is used, and examples of the material include a polyolefin resin such as polyethylene and a fluorine resin such as polyvinylidene fluoride.

  The shape, form, etc. of the non-aqueous secondary battery according to this embodiment are not particularly limited, and are arbitrarily selected within the scope of the present invention, such as a cylindrical shape, a square shape, a coin shape, a card shape, and a large size. be able to.

Hereinafter, the present invention will be described in detail using examples, but the present invention is not limited to the examples.
Donor number and flash point of liquid composition

Example 1
4.5 g of tributyl phosphate (boiling point 289 ° C.) and 25.5 g of tris phosphate (2,2,2-trifluoroethyl) (boiling point 204 ° C., F / H ratio = 1.50) were mixed. The mixture became a homogeneous phase. In addition, the boiling point described in this specification shows the value which carried out normal pressure conversion of the boiling-point measured value under reduced pressure distillation using a boiling point conversion chart (Science of Petroleum, Vol.II 1281 (1938)).

Example 2
9.0 g of tributyl phosphate (boiling point 289 ° C.) and 21.0 g of tris phosphate (2,2,2-trifluoroethyl) (boiling point 204 ° C., F / H ratio = 1.50) were mixed. The mixture became a homogeneous phase.

Example 3
15.0 g of tributyl phosphate (boiling point 289 ° C.) and 15.0 g of tris phosphate (2,2,2-trifluoroethyl) (boiling point 204 ° C., F / H ratio = 1.50) were mixed. The mixture became a homogeneous phase.

Example 4
21.0 g of tributyl phosphate (boiling point 289 ° C.) and 9.0 g of tris phosphate (2,2,2-trifluoroethyl) (boiling point 204 ° C., F / H ratio = 1.50) were mixed. The mixture became a homogeneous phase.

Example 5
4.5 g of tributyl phosphate (boiling point 289 ° C.) and 25.5 g of tris phosphate (2,2,2-trifluoroethyl) (boiling point 204 ° C., F / H ratio = 1.50) were mixed. The mixture became a homogeneous phase.

Example 6
15.0 g of triethyl phosphate (boiling point 210 ° C.) and 15.0 g of tris phosphate (2,2,2-trifluoroethyl) (boiling point 204 ° C., F / H ratio = 1.50) were mixed. The mixture became a homogeneous phase.

Example 7
15.0 g of tributyl phosphate (boiling point 289 ° C.) and 15.0 g of bis (2,2,2-trifluoroethyl) ethyl phosphate (boiling point 185 ° C., F / H ratio = 0.67) were mixed. The mixture became a homogeneous phase.

Example 8
15.0 g of triethyl phosphate (boiling point 210 ° C.) and 15.0 g of bis (2,2,2-trifluoroethyl) ethyl phosphate (boiling point 185 ° C., F / H ratio = 0.67) were mixed. The mixture became a homogeneous phase.

Example 9
15.0 g of tris phosphate (2-ethylhexyl) (boiling point 400 ° C.) and 15.0 g of tris phosphate (2,2,3,3-tetrafluoropropyl) (boiling point 345 ° C., F / H ratio = 1.33) Were mixed. The mixture became a homogeneous phase.

Example 10
15.0 g of diethyldiisopropylamide phosphate (boiling point 230 ° C.) and 15.0 g of tris (2,2,2-trifluoroethyl phosphate) (boiling point 204 ° C., F / H ratio = 1.50) were mixed. The mixture became a homogeneous phase.

Example 11
15.0 g of phosphoric acid ethylbisdimethylamide (boiling point 214 ° C.) and 15.0 g of tris (2,2,2-trifluoroethyl phosphate) (boiling point 204 ° C., F / H ratio = 1.50) were mixed. The mixture became a homogeneous phase.

Example 12
15.0 g of hexamethylphosphoric triamide (boiling point 235 ° C.) and 15.0 g of tris phosphate (2,2,2-trifluoroethyl) (boiling point 204 ° C., F / H = 1.50) were mixed. The mixture became a homogeneous phase.

Comparative Example 1
Tris (2,2,2-trifluoroethyl) phosphate (boiling point 204 ° C., F / H ratio = 1.50) alone liquid.

Comparative Example 2
1.5 g of tributyl phosphate (boiling point 289 ° C.) and 28.5 g of tris (2,2,2-trifluoroethyl phosphate) (boiling point 204 ° C., F / H ratio = 1.50) were mixed. The mixture became a homogeneous phase.

Comparative Example 3
28.5 g of tributyl phosphate (boiling point 289 ° C.) and 1.5 g of tris phosphate (2,2,2-trifluoroethyl) (boiling point 204 ° C., F / H ratio = 1.50) were mixed. The mixture became a homogeneous phase.

Comparative Example 4
Tributyl phosphate (boiling point 289 ° C) single liquid

Comparative Example 5
1.5 g of triethyl phosphate (boiling point 210 ° C.) and 28.5 g of tris phosphate (2,2,2-trifluoroethyl) (boiling point 204 ° C., F / H ratio = 1.50) were mixed. The mixture became a homogeneous phase.

Comparative Example 6
28.5 g of triethyl phosphate (boiling point 289 ° C.) and 1.5 g of tris phosphate (2,2,2-trifluoroethyl) (boiling point 204 ° C., F / H ratio = 1.50) were mixed. The mixture became a homogeneous phase.

Comparative Example 7
15.0 g of trimethyl phosphate (boiling point 197 ° C.) and 15.0 g of tris phosphate (2,2,2-trifluoroethyl) (boiling point 204 ° C., F / H ratio = 1.50) were mixed. The mixture became a homogeneous phase.

Comparative Example 8
15.0 g of triethyl phosphate (boiling point 210 ° C.) and 15.0 g of bis (2-fluoroethyl) ethyl phosphate (boiling point 205 ° C., F / H ratio = 0.15) were mixed. The mixture became a homogeneous phase.

Comparative Example 9
4.5 g of triethyl phosphate (boiling point 210 ° C.) and 25.5 g of tris (perfluoropropyl) amine were mixed. The mixed solution became a two-layer solution.

Comparative Example 10
15.0 g of triethyl phosphate (boiling point 210 ° C.) and 15.0 g of tris (perfluoropropyl) amine were mixed. The mixed solution became a two-layer solution.

Comparative Example 11
25.5 g of triethyl phosphate (boiling point 210 ° C.) and 4.5 g of tris (perfluoropropyl) amine were mixed. The mixed solution became a two-layer solution.

Comparative Example 12
15.0 g of diethyldiisopropylamide phosphate (boiling point 230 ° C.) and 15.0 g of tris (perfluoropropyl) amine were mixed. The mixed solution became a two-layer solution.

Comparative Example 13
15.0 g of triethyl phosphate (boiling point 210 ° C.) and 15.0 g of perfluorohexane were mixed. The mixed solution became a two-layer solution.

About each liquid composition of Examples 1-12 and Comparative Examples 1-8, J.M. Organomet. Chem. , 108, 153 (1076), the number of donors was measured. That is, 0.15 g of diphenylsilanediol was collected in a sample bottle, and 3 ml of the liquid composition was added and dissolved. Next, the solution was transferred to a 10 mmφ Teflon tube, and ²⁹ Si NMR was measured (Varian VNMRS-400, cumulative number 256 times, external reference TMS). A calibration curve obtained from the measurement results of DMSO (−34.0 ppm, donor number = 29.8) and acetone (−31.9 ppm, donor number = 17.0) from the chemical shift value of the observed signal was used. The number of donors was calculated.

  About each liquid composition of Examples 1-12 and Comparative Examples 1-8, the flash point was measured using the setter type flash point tester (RT-1 type made by ERDCO Engineering Corporation). That is, the RT-1 tester was heated to a predetermined temperature, and when the temperature became constant, 4 ml of an electrolytic solution was injected. After 2 minutes, the test flame was observed while looking inside the switch, and the presence or absence of ignition was observed. The results are shown in Table 1.

  In Table 1, as shown in Examples 1 to 12, a fluorine-containing phosphate ester having an F / H ratio of 0.2 or more and a lower boiling point than phosphate ester, phosphate ester amide or phosphate triamide, When mixed at 10 to 90% by weight, the liquid mixture is highly non-flammable despite the fact that the number of donors shows a high value close to that of phosphate ester, phosphate ester amide or phosphate triamide alone. It can be seen that the flame retardancy is excellent. On the other hand, when the fluorine-containing phosphate ester content is less than 10% by weight as in Comparative Examples 3 to 4 and 6, fluorine-containing phosphoric acid having an F / H ratio of less than 0.2 as in Comparative Example 8 When 10% or more of the ester is mixed, or when 10% or more of the fluorine-containing phosphoric ester having a boiling point higher than that of the phosphate ester is mixed as in Comparative Example 7, the flash point is observed and the flame retardancy is not good. It is enough. Moreover, when the fluorine-containing phosphate ester abundance exceeds 90% by weight as in Comparative Examples 1 to 2, and 5 because the donor property is very low, diphenylsilanediol does not dissolve, and the number of donors is measured. Could not do. Further, as in Comparative Examples 9 to 13, when tris (perfluoropropyl) amine or perfluorohexane is mixed as a known liquid having no flash point, the liquid becomes a two-layer liquid, and a uniform liquid composition I couldn't get anything.

Examples 13-22, Comparative Examples 14-19
Example of Metal Extraction Using Liquid Composition Using the liquid compositions of Examples 1 to 7, Examples 10 to 12, and Comparative Examples 1 to 6, Pt (platinum) was extracted by the following operation. The results are shown in Table 2 as Examples 14 to 22 and Comparative Examples 14 to 19, respectively.

  10 g of 4N hydrochloric acid (Pt concentration 0.57 wt%) in which chloroplatinic acid was dissolved was placed in a separatory funnel, 10 ml of each liquid composition was added, and the mixture was shaken for 1 minute. After standing for 5 minutes, the two layers were separated, the water layer was weighed, and the Pt concentration was measured by the ICP method. The extraction rate of Pt was calculated by the following formula.

  Extraction rate (%) = [0.057 (g) −weight of water layer after extraction (g) × Pt concentration (wt%)] / 0.057 × 100

  From Table 2, Examples 14-22 using the liquid composition of this embodiment have a high flame retardancy without having a flash point, and also in the extraction rate of Pt, a fluorine-containing phosphate ester. It can be seen that it is remarkably superior to the case of containing more than 90% (Comparative Examples 14 to 15 and 18). Moreover, Examples 14-22 are excellent in Pt extraction rate compared with the case (Comparative Examples 16-17, 19) which uses the liquid which contains fluorine-containing phosphate ester less than 10%, and has a flash point. I know that. In Comparative Example 19, the liquid became uniform and extraction was impossible.

Examples 23-26, Comparative Examples 20-22
Examples of non-aqueous electrolytes for lithium ion secondary batteries using a liquid composition as a solvent Using the liquid compositions of Example 6, Example 8, Comparative Example 5 and Comparative Example 6 as a solvent and LiPF ₆ as an electrolyte salt, respectively 1 mol / L was dissolved. Moreover, the liquid composition of Example 6 and Example 8 was used as a solvent, and 1 mol / L of LiN (CF ₃ SO ₂ ) ₂ was dissolved as an electrolyte salt.

Further, 10.0 g of triethyl phosphate and 10.0 g of methyl perfluorohexyl ether were mixed, and LiPF ₆ was added and mixed so as to have a concentration of 1 mol / L.

  Next, for each of the above non-aqueous electrolytes, the flash point was measured using a setter flash point tester (RT-1 type manufactured by ERDCO Engineering Corporation), and an electric conductivity meter (CM-117 type manufactured by Kyoto Electronics Co., Ltd.) was used. The electrical conductivity at 25 ° C. was measured. The results are shown in Table 3 as Examples 23 to 26 and Comparative Examples 20 to 22, respectively.

  As shown in Table 3, all of the non-aqueous electrolytes of Examples 23 to 26 using the non-flammable liquid composition of this embodiment as a solvent are non-flammable and non-flammable highly flame retardant. In addition to being a liquid, the electrolyte salt could be dissolved at a concentration of 1 mol / L and showed high electrical conductivity. On the other hand, in the electrolyte solution of Comparative Example 20 in which the weight fraction of the fluorine-containing phosphate ester was less than 10%, the flash point was observed and the flame retardancy was insufficient. Further, Comparative Example 21 using a liquid composition in which the weight fraction of the fluorine-containing phosphate ester exceeded 90% showed a remarkably low electrical conductivity. Further, Comparative Example 22 using methyl perfluorohexyl ether, which is a known liquid that does not have a flash point, is suitable as an electrolyte because the liquid mixture becomes a two-layer liquid and the flash point and electrical conductivity cannot be measured. There was no state.

Examples 27-30, Comparative Examples 23-24
Using lithium cobaltate (LiCoO ₂₎ a liquid composition as creating a positive electrode active material of the non-aqueous electrolyte lithium ion secondary batteries Example <br/> lithium ion secondary battery using the as a solvent, to which conductive additive As a carbon black, polyvinylidene fluoride (PVDF) as a binder is blended so as to be LiCoO ₂ : carbon black: PVDF = 85: 7: 8, and slurried using 1-methyl-2-pyrrolidone is made of aluminum The positive electrode was obtained by applying a constant film thickness on the current collector and drying it. Hard carbon is used as the negative electrode active material, PVDF is blended as a binder with a ratio of graphite: PVDF = 9: 1, and a slurry obtained using 1-methyl-2-pyrrolidone is fixed on a copper current collector. The negative electrode was obtained by applying and drying. As the separator, an inorganic filler-impregnated polyolefin porous membrane was used.

  Using the above components, a lithium secondary battery using a coin-type cell having the structure shown in FIG. 1 was produced. In the lithium secondary battery, a positive electrode 1 and a negative electrode 4 are arranged opposite to each other with a separator 6 interposed therebetween, a stainless steel leaf spring 5 is installed on a negative electrode stainless steel cap 3, and a laminate including the negative electrode 4, the separator 6, and the positive electrode 1 is coin-shaped. Stored in the cell. After injecting the non-aqueous electrolytes of Examples 23 to 26 and Comparative Examples 20 to 21 into this laminate, the gasket 7 was placed, and then the positive electrode stainless steel cap 2 was put on and the coin type cell case was caulked. .

Charge / Discharge Test The lithium ion secondary battery prepared by the method of the above battery preparation example was charged at a constant current of 25 ° C. with a charging current of 0.1 C and a maximum voltage of 4.2 V, and subsequently a discharging current of 0.1 C. The battery was discharged until 3.0V. After performing this operation three times, under a constant temperature condition of 25 ° C., a constant current-constant voltage charge of 4.2 V is performed with a charging current of 0.2 C, and a constant current is reached up to a final voltage of 3.0 V with a discharging current of 0.2 C. Discharge was performed. The discharge capacity at this time was defined as the initial discharge capacity, the discharge capacity when this operation was repeated 25 times was measured, and the comparison was performed using the discharge capacity / initial discharge capacity ratio after 25 cycles as the capacity retention rate. The results are shown in Table 4 as Examples 27 to 30 and Comparative Examples 23 to 24, respectively.

Examples 31-32
A non-aqueous two-crystal system was prepared in the same manner as in Examples 27 to 30 except that LiNi _1/4 Mn _3/4 O ₂ was used as the positive electrode active material and the non-aqueous electrolytes of Examples 23 to 24 were used as the non-aqueous electrolyte. Next battery was made. Moreover, the charge / discharge test was done by the method similar to Examples 27-30 except having made the upper limit voltage into 4.5V. The results are shown in Table 4 as Examples 31-32.

Examples 33-34
Non-aqueous secondary in the same manner as in Examples 27 to 30 except that lithium titanate (LiTiO ₂ ) was used as the negative electrode active material and the non-aqueous electrolytes of Example 23 and Example 24 were used as the non-aqueous electrolyte. A battery was created. Moreover, the charge / discharge test was done by the same method as Examples 27-30. The results are shown in Table 4 as Examples 33 to 34.

  From Table 4, Examples 27 to 34, which are lithium ion secondary batteries containing the non-flammable liquid composition of the present embodiment as a non-aqueous electrolyte solvent, have a weight fraction of fluorine-containing phosphate of less than 10%. Compared to Comparative Example 23 using a certain liquid composition as a solvent and Comparative Example 24 including a non-aqueous electrolyte using a liquid composition having a weight fraction of fluorine-containing phosphate ester exceeding 90% as a solvent, capacity retention rate It can be seen that the battery performance is high and the battery performance is excellent. Moreover, it turns out that Example 31 and Example 32 which used the nonflammable liquid composition of this embodiment as a nonaqueous electrolyte solvent show a favorable capacity | capacitance maintenance factor also in charging / discharging of the upper limit voltage 4.5V. Furthermore, Example 33 and Example 34 using lithium titanate as the negative electrode active material showed a very good capacity retention rate.

Examples 35-36
Example of non-aqueous electrolyte for lithium ion secondary battery using liquid composition and cyclic carbonate as solvent: Triethyl phosphate, tris phosphate (2,2,2-trifluoroethyl) and ethylene carbonate in weight ratio of 35:35 The mixture was mixed at a ratio of 30 and 1 mol / L of LiPF ₆ was dissolved in the mixed liquid as an electrolyte salt (Example 35). Similarly, triethyl phosphate, bis (2,2,2-trifluoroethyl) ethyl phosphate and ethylene carbonate are mixed at a weight ratio of 35:35:30, and LiPF ₆ is used as an electrolyte salt in this mixed liquid. Each was dissolved at 1 mol / L (Example 36).

  Next, for each of the above non-aqueous electrolytes, the flash point was measured using a setter flash point tester (RT-1 type manufactured by ERDCO Engineering Corporation), and an electric conductivity meter (CM-117 type manufactured by Kyoto Electronics Co., Ltd.) was used. The electrical conductivity at 25 ° C. was measured. The results are shown in Table 5.

  As shown in Table 5, the non-flammable liquid compositions of Examples 35 and 36 and the non-aqueous electrolyte using the cyclic carbonate as a solvent have high non-flammable flame retardancy. Moreover, it turns out that a higher electrical conductivity is shown by containing a cyclic carbonate as a solvent in addition to the non-flammable liquid composition of the present embodiment.

Examples 37-40
Example of lithium ion secondary battery using non-aqueous electrolyte using liquid composition and cyclic carbonate as solvent Solving non-aqueous electrolyte of Examples 23, 24, 35 and 36 in the same manner as Examples 27-30 A non-aqueous secondary battery was prepared. Next, these non-aqueous secondary batteries were charged at a constant temperature of 25 ° C. with a charging current of 0.1 C and an upper limit voltage of 4.2 V, and then discharged to a voltage of 3.0 V with a discharging current of 0.1 C. did. After performing this operation three times, under a constant temperature condition of 25 ° C., a constant current-constant voltage charge of 4.2 V is performed with a charging current of 0.2 C, and a constant current is reached up to a final voltage of 3.0 V with a discharging current of 0.2 C. Discharge was performed. Next, a constant current-constant voltage charge of 4.2 V was performed at a charging current of 0.5 C under a constant temperature condition of 25 ° C., and a constant current discharge was performed to a final voltage of 3.0 V with a discharge current of 0.5 C. The discharge capacity at 0.5 C relative to the discharge capacity at 0.2 C was determined as a capacity ratio (%). The results are shown in Table 6.

As shown in Table 6, the non-aqueous secondary batteries (Examples 38 and 40) using the non-flammable liquid composition of the present embodiment and the non-aqueous electrolyte using the cyclic carbonate as a solvent include cyclic carbonate. It can be seen that charge and discharge can be performed satisfactorily in Examples 37 and 39, which are not present, and that the combined use of cyclic carbonate improves the charge / discharge characteristics at a high rate.
Examples 41-43, Comparative Example 25
Example of dissolving oil using liquid composition as solvent 1.0 g of each of the liquid compositions of Example 3, Examples 9 to 10 and Comparative Example 2 was collected in a sample bottle and pump oil MR-100 (manufactured by MORESCO). 1 g was added and shaken. After standing, the state of the liquid was visually confirmed. The results are shown in Table 7 as Examples 41 to 43 and Comparative Example 25, respectively.

  In Examples 41 to 43 using the non-flammable liquid composition of the present embodiment, all have excellent compatibility with organic compounds. Therefore, the pump oil is dissolved, and nonflammable high flame retardancy is exhibited. It was shown that it can be used as a cleaning agent. On the other hand, Comparative Example 25 containing more than 90% of the fluorine-containing phosphate ester did not dissolve the pump oil because the compatibility with the organic compound was not sufficient.

  The non-flammable liquid composition of the present invention has high nonflammability and high flame retardancy, and has high donor properties and excellent compatibility with organic compounds and salts. Therefore, a highly safe and efficient metal salt extraction method, a non-aqueous electrolyte solution with high safety and high electrical conductivity, a non-aqueous secondary battery containing the same, and the like are provided and are extremely useful.

DESCRIPTION OF SYMBOLS 1 Positive electrode 2 Positive electrode stainless steel cap 3 Negative electrode stainless steel cap 4 Negative electrode 5 Stainless steel spring 6 Inorganic filler impregnation polyolefin porous separator 7 Gasket

Claims (12)

The following general formula (1)

(In the formula, n represents an integer of 0 to ^3. R ¹ , R ² and R ³ are each independently a linear or branched alkyl group having 1 to 10 carbon atoms, an alkenyl group or 6 to 10 carbon atoms. Represents an aryl group, and R ² and R ³ may be bonded to each other to form a 5- to 8-membered cyclic structure.
The phosphoric acid ester, phosphoric acid ester amide or phosphoric acid amide represented by the following general formula (2)

(In the formula, m represents an integer of 1 to 3. Rf represents a linear or branched fluorine-containing alkyl group having 1 to 10 carbon atoms, and R ⁴ represents a linear or branched carbon group having 1 to 10 carbon atoms. Represents an alkyl group, an alkenyl group or an aryl group having 6 to 10 carbon atoms, provided that the ratio of the number of fluorine atoms to the number of hydrogen atoms in the whole molecule is 0.2 or more.)
Wherein the fluorine-containing phosphate ester of the general formula (2) is a phosphate ester, phosphate ester amide or phosphoric acid of the general formula (1) It has a lower boiling point than amide, and the weight fraction of the fluorine-containing phosphate ester of the general formula (2) is 10 to 90% of the entire liquid composition, and the liquid composition does not have a flash point. A non-flammable liquid composition characterized by the above.   2. The non-flammable liquid composition according to claim 1, wherein a weight fraction of the fluorine-containing phosphate ester of the general formula (2) is 30 to 70% of the entire liquid composition. The said General formula (1) WHEREIN: R < ¹ >, R < ² > and R < ³ > are respectively independently a C1-C4 linear or branched alkyl group, The Claim 1 or Claim 2 characterized by the above-mentioned. Non-flammable liquid composition.   In the said General formula (1), n is 0, The non-flammable liquid composition of any one of Claims 1-3 characterized by the above-mentioned.   In the said General formula (1), n is 1, The nonflammable liquid composition of any one of Claims 1-3 characterized by the above-mentioned. In the general formula (2), R ⁴ is a linear or branched alkyl group having 1 to ⁴ carbon atoms, and Rf is a linear or branched fluorine-containing alkyl group having 1 to 3 carbon atoms. The non-flammable liquid composition according to any one of claims 1 to 5.   In the said General formula (2), m is 2, The nonflammable liquid composition of any one of Claims 1-6 characterized by the above-mentioned.   In the said General formula (2), m is 3, The nonflammable liquid composition of any one of Claims 1-6 characterized by the above-mentioned.   A metal extraction method comprising extracting a metal component from an aqueous solution containing metal ions using the non-flammable liquid composition according to any one of claims 1 to 8 as an extraction solvent.   A non-aqueous secondary battery comprising a solvent containing the non-flammable liquid composition according to any one of claims 1 to 8 and a lithium salt dissolved in the solvent. Non-aqueous electrolyte.   The non-aqueous electrolyte for a non-aqueous secondary battery according to claim 10, wherein the solvent further contains a cyclic carbonate. A non-aqueous secondary battery comprising the non-aqueous electrolyte according to claim 10.