JP4820993B2 - Organic liquid gelling agent comprising aromatic compound having perfluoroalkyl group - Google Patents

Description

  The present invention relates to an organic liquid gelling agent containing a novel perfluoroalkyl derivative as an active ingredient, and an organic liquid gel gelled using the gelling agent. The organic liquid gel of the present invention can be used as a gel electrolyte.

Lithium Ion Battery Electrolyte The electrolyte of a lithium ion battery is generally a liquid, but a gel or solid is also used as a polymer electrolyte. In any electrolyte, the following characteristics are required.
1) High conductivity (high mobility of lithium ions)
2) Large chemical and electrochemical stability for electrode materials 3) Wide usable temperature range 4) High safety 5) Low price Electrolyte solvent High concentration of lithium salt and high conductivity As the solvent, an aprotic organic solvent having a large relative dielectric constant and a small viscosity is suitable. However, since the relative permittivity is large and the viscosity of the solvent having a strong polarity is increased, the practical electrolytic solution is a mixture of a plurality of solvents. For example, propylene carbonate (PC) having a dielectric constant of 64.4 and a viscosity of 2.3 cp, or a mixture of ethylene carbonate (EC) having a dielectric constant of 95.3 and a viscosity of 1.9 cp and dimethyl carbonate (DMC) having a viscosity of 0.59 cp. Solvents are known. These mixed solvents have compositions exhibiting maximum conductivity, and the compositions have been studied in detail along with the types of electrolyte salts to be added.

As the electrolyte salt electrolyte salt, other lithium perchlorate (LiClO _4), LiPF ₆ containing _{fluorine, LiAsF 6, Li (CF 3} SO 2) 2 N, such as LiBF _3, LiCF 3 SO 3 is used . The ionic conductivity of the organic solvent electrolyte in which these are dissolved is about 10 ⁻² S / cm.

Gel Electrolyte Gel electrolyte, which is a mixture of an organic polymer and a liquid electrolyte, has a high ionic conductivity and has a history of commercialization earlier than solid electrolytes. The gel electrolyte uses a carbon-based negative electrode material and is applied as a lithium ion secondary battery, particularly a thin film battery.

Gelling agents in various technical fields Conventionally, organic liquids (animal and vegetable oils and fats) in various industrial fields such as paints, inks, lubricants, agriculture, fisheries, cosmetics, pharmaceuticals, fibers, resins, polymers, rubbers, metals, etc. , Esters, polyols, ethers, alcohols, hydrocarbons, etc.) have been used to solidify low-molecular gelling agents or high-molecular gelling agents. Polymer gelling agents are often used in the technical field of batteries as gelling agents for gel electrolytes.

Low molecular weight organic gelling agent Although development of a low molecular weight gelling agent is slower than this, 12-hydroxystearic acid, dialkylurea derivatives, dibenzylidene sorbitol, and the like are known.

  Among them, 12-hydroxystearic acid is inexpensive, but there are few kinds of organic liquids that can be gelled, and the temperature at which the obtained gel softens is also low. There are few types of organic liquids that can be gelled with dialkylurea derivatives. On the other hand, although dibenzylidene sorbitol forms a strong gel with a small amount of addition, it has the disadvantage of liberating benzaldehyde, and because it has a high melting point, it is not suitable for solidifying low-boiling short-chain alcohols. is there. Alkali metal salts and alkaline earth metal salts of fatty acids require a large amount of addition for gelation or solidification, and have limitations such as limited usable conditions.

Perfluoroalkylalkanes Perfluoroalkylalkanes: F (CF ₂ ) n (CH ₂ ) mH has n = 12, m = 8-20, gelling decane, n = 10, m = 12. It has been reported that a hydrocarbon solvent is gelled (Non-patent Document 1).

It has been reported that perfluoroalkylalkane: F (CF ₂ ) ₈ (CH ₂ ) ₈ H gels methyl alcohol, ethyl alcohol, and propyl alcohol (Non-patent Document 2).

Disadvantages of the prior art However, there are many types of organic liquids that can be gelled, and no organic low-molecular gelling agent that can be gelled with a small amount of addition has been known so far. And the organic low molecular weight gelatinizer which gelatinizes the high dielectric constant solvent suitable for organic electrolyte solution was not known.
Robert J. et al. Twang, et al, “Observations of a“ Gel ”Phase in Binary Mixture of Semifluorinated n-Alkanes with Hydrocarbon Liquids, 1985, 1836, 1836. Massimo Napoli, et al, "Synthesis of F (Ch2) 8 (Ch2) 8H and gel phase formation from solutions in homologous alcohols.

  An object of the present invention is to provide an organic low-molecular gelling agent that has many kinds of organic liquids that can be gelled and that can be gelled with a small amount of addition. An object of this invention is to provide the organic low molecular weight gelatinizer which can gelatinize the high dielectric constant solvent suitable for organic electrolyte solution. An object of this invention is to provide the gel formed by gelatinizing an organic liquid with this organic low molecular weight compound.

  The present inventors newly synthesized an aromatic compound having a perfluoroalkyl group, and surprisingly, it was found that this compound can be gelled with a small amount of addition of most organic liquids. The gelling agent comprising this compound can be gelled by adding a small amount of most organic liquids.

Gelling agent of the present invention The gelling agent of the present invention gels an organic liquid. The gelling agent of the present invention comprises a perfluoroalkyl (oligomethylene) thio group and an aromatic compound having a hydrocarbon oxy group represented by the following chemical formula (1).

（式中、
基Ｃ_ｍＦ_２ｍ＋１は、ペルフルオロアルキル基、ｍは、６〜１２の自然数；
基（ＣＨ_２）は、メチレン基、ｐはメチレン基の数で、０又は１〜４の自然数；
基Ｓは、イオウ原子；
基Ａｒは、置換もしくは無置換の核原子数５〜３０の２価の芳香族基；
基Oは、酸素原子；
基Ｒは、飽和もしくは不飽和の炭素数１〜２０の１価の炭化水素基である。）
本発明のゲル化剤の製造方法
本発明のゲル化剤の製造方法は、下記化学式（２）の水酸基とチオール基を有する芳香族化合物を、下記化学式（３）のペルフルオロアルキル（オリゴメチレン）基を有するハロゲン化化合物と、反応させ、下記化学式４の水酸基及びペルフルオロアルキル（オリゴメチレン）基を有する芳香族化合物を生成させ、この生成物（化学式４）をハロゲン化炭化水素と反応させることからなる。

(Where
The group C _m F _{2m + 1} is a perfluoroalkyl group, m is a natural number from 6 to 12;
The group (CH ₂ ) is a methylene group, p is the number of methylene groups, and a natural number of 0 or 1 to 4;
The group S is a sulfur atom;
The group Ar is a substituted or unsubstituted divalent aromatic group having 5 to 30 nuclear atoms;
The group O is an oxygen atom;
The group R is a saturated or unsaturated monovalent hydrocarbon group having 1 to 20 carbon atoms. )
Method for Producing Gelling Agent of the Present Invention The method for producing the gelling agent of the present invention comprises converting an aromatic compound having a hydroxyl group and a thiol group represented by the following chemical formula (2) into a perfluoroalkyl (oligomethylene) group represented by the following chemical formula (3). And reacting with a halogenated compound having the following formula to form an aromatic compound having a hydroxyl group and a perfluoroalkyl (oligomethylene) group of the following chemical formula 4, and reacting the product (chemical formula 4) with a halogenated hydrocarbon: .

（式中の記号の意味は、化学式１の場合と同じ。基Ｘはチオール基に反応性のハロゲン原子）。

(The meaning of the symbols in the formula is the same as in the case of Chemical Formula 1. The group X is a halogen atom reactive with a thiol group).

Gel of the present invention The gelling agent or gel of the present invention is an industry including processing fields such as battery electrolytes, paints, inks, lubricants, agriculture, fisheries, cosmetics, pharmaceuticals, fibers, resins, polymers, rubbers, metals, etc. Used in the field. Especially, the gel which consists of an organic ionic liquid, and the gel containing the ionic substance melt | dissolved in an organic solvent can be used suitably as electrolytes of batteries, such as a lithium ion battery and a dye-sensitized solar cell.

  The gelling agent of the present invention has many kinds of organic liquids that can be gelled, and can gel the organic liquid with a small amount of addition. The gelling agent of the present invention can gel a high dielectric constant solvent suitable for an organic electrolyte. Since the gel produced by gelling a high dielectric constant solvent with the gelling agent of the present invention has a low concentration of the gelling agent, it can advantageously increase the content of the organic electrolyte when used as an electrolyte gel. .

Compound used as gelling agent of the present invention The compound used as the gelling agent of the present invention is an aromatic compound having a perfluoroalkyl (oligomethylene) thio group and a hydrocarbon oxy group. The compound used as the gelling agent of the present invention is represented by the following chemical formula 1.

（式中、
基Ｃ_ｍＦ_２ｍ＋1は、ペルフルオロアルキル基、ｍは、６〜１２の自然数；
基（ＣＨ_２）は、メチレン基、ｐは、０又は１〜４の自然数；
基Ｓは、イオウ原子；
基Ａｒは、置換もしくは無置換の核原子数５〜３０の２価の芳香族基；
基Oは、酸素原子；
基Ｒは、飽和もしくは不飽和の炭素数１〜２０の１価の炭化水素基である）。

(Where
The group C _m F _{2m + 1} is a perfluoroalkyl group, m is a natural number of 6-12;
The group (CH ₂ ) is a methylene group, p is 0 or a natural number of 1 to 4;
The group S is a sulfur atom;
The group Ar is a substituted or unsubstituted divalent aromatic group having 5 to 30 nuclear atoms;
The group O is an oxygen atom;
The group R is a saturated or unsaturated monovalent hydrocarbon group having 1 to 20 carbon atoms).

Production Method of Aromatic Compound of the Present Invention The aromatic compound of the present invention comprises (1) a perfluoroalkyl (oligomethylene) thio group introduced into an aromatic compound (chemical formula 2) having a hydroxyl group and a thiol group, and (2) a hydrocarbon. It can be produced by introducing an oxy group.
(1) Introduction of perfluoroalkyl (oligomethylene) thio group An aromatic compound having a hydroxyl group and a thiol group (chemical formula (2)) is dissolved in a solvent such as tetrahydrofuran (THF), and perfluoroalkyl in the presence of a base such as an amine. Aromatic compound having a hydroxyl group and a perfluoroalkyl (oligomethylene) group by reacting with a halogenated compound having (oligomethylene) group (chemical formula (3)), neutralizing with hydrochloric acid, distilling off the solvent and unreacted substances. A compound (chemical formula (4)) is produced.

（式中の記号の意味は、化学式1の場合と同じ。基Ｘはチオール基に反応性のハロゲン原子）
（２） 炭化水素オキシ基の導入
水酸基及びペルフルオロアルキル（オリゴメチレン）基を有する芳香族化合物（化学式４）を溶媒に溶解した溶液に、ハロゲン化炭化水素と塩基を加え還流する。反応終了後、必要に応じて一旦濾過し、反応液から溶媒及び未反応物質を留去し、残渣をシリカゲルクロマトグラフにより精製することにより、炭化水素オキシ基を導入して、ペルフルオロアルキル（オリゴメチレン）チオ基と炭化水素オキシ基とを有する、芳香族化合物（化学式（１））を製造する。

(The meaning of the symbols in the formula is the same as in the chemical formula 1. The group X is a halogen atom reactive with the thiol group)
(2) Introduction of hydrocarbon oxy group A halogenated hydrocarbon and a base are added to a solution in which an aromatic compound (chemical formula 4) having a hydroxyl group and a perfluoroalkyl (oligomethylene) group is dissolved in a solvent, and the mixture is refluxed. After completion of the reaction, if necessary, the mixture is filtered once, the solvent and unreacted substances are distilled off from the reaction solution, and the residue is purified by silica gel chromatography to introduce hydrocarbon oxy groups, and perfluoroalkyl (oligomethylene). ) An aromatic compound (chemical formula (1)) having a thio group and a hydrocarbon oxy group is produced.

  Of course, the method for producing the aromatic compound of the present invention is not limited to the above method.

Aromatic group Ar
In the present specification, the aromatic group Ar is a divalent group of a cyclic compound exhibiting so-called “aromaticity”. The cyclic compound may be a carbocyclic compound or a heterocyclic compound. These cyclic compounds may be substituted with a substituent or may not be substituted. Substituents unfavorable for (1) introduction of perfluoroalkyl (oligomethylene) thio group and (2) introduction of hydrocarbon oxy group are aromatic compounds having a hydroxyl group and a thiol group (compound chemical formula (2)). It is not preferred as a substituent.

  In the case of an aromatic carbocyclic compound group, the number of nuclear atoms is 6 to 30, and it may be substituted with a substituent or may not be substituted. For example, compounds having a nucleus such as a phenylene group, a biphenylene group, a terphenylene group, a naphthylene group, an anthranylene group, a phenanthrylene group, a pyrenylene group, a chrysenylene group, and a fluoranthenylene group can be given.

  In the case of an aromatic heterocyclic compound, the number of nuclear atoms is 5 to 30, and examples thereof include a pyrrolene group, a furanylene group, a thiophenylene group, a triazolen group, an oxadiazolene group, a pyridylene group, and a pyrimidylene group. Examples include compounds having a nucleus.

  Among these, as the aromatic group Ar, a phenylene group, a biphenylene group, or a naphthylene group is preferable.

  Examples of the substituent include an alkyl group such as a methyl group and an ethyl group, and a halogen atom.

Perfluoroalkyl group C _m F _{2m + 1}
In the present specification, the perfluoroalkyl group C _m F _{2m + 1} is a perfluoroalkyl group having 6 to 12 carbon atoms. When the carbon number m is 5 or less, the compound of the chemical formula (1) has a low gelling ability. When the carbon number m is 13 or more, the compound of the chemical formula (1) does not dissolve even if it is overheated depending on the type of the organic solvent.

Oligomethylene Group In the compound of the present invention, the oligomethylene group (CH ₂ ) _p may have 0 carbon atoms and no oligomethylene group. In the compound of the present invention, the oligomethylene group (CH ₂ ) _p has 0 to 4 carbon atoms. When the number of carbon atoms of the oligomethylene group (CH ₂ ) _p is 5 or more, the compound of formula 1 has a low gelling ability.

Hydrocarbon group R
In the present specification, the hydrocarbon group R is a saturated or unsaturated monovalent hydrocarbon group having 1 to 20 carbon atoms. The hydrocarbon group R may be branched in the case of an aliphatic hydrocarbon, or may not be branched. Moreover, when an aromatic hydrocarbon is included, a substituent may exist in the aromatic. Of course, without the hydrocarbon group R, which may be an arylalkyl group such as a benzyl group, the compound of the chemical formula (1) does not dissolve in the organic liquid, and the organic liquid cannot be gelled. When the number of carbon atoms is 21 or more, it is difficult to obtain raw materials.

In a halogen atom herein, halogenated compounds _C m _F 2m + 1 with perfluoroalkyl (oligomethylene) group - as _{(CH 2)} p -X halogen atom X in the chemical formula (2) (HS-Ar- OH) It may be reactive to the thiol group (SH), and chlorine, bromine, iodine, and fluorine can be used.

  The halogen atom of the halogenated hydrocarbon used for introducing the hydrocarbon oxy group may be reactive with the hydroxyl group OH of the compound 4, and chlorine, bromine, iodine, and fluorine can be used.

Gelling of organic liquid The gelling agent of the present invention gels almost all organic liquids by adding a small amount of about 5% or less. The gelling agent of the present invention is added to an organic solvent, dissolved by heating, and the resulting solution is gelled by returning it to room temperature. The gelling agent of the present invention can gel a high dielectric constant solvent suitable for an organic electrolyte, for example, propylene carbonate. The gel produced by gelling a high dielectric constant solvent with the gelling agent of the present invention can be used as an electrolyte gel. This electrolyte gel can be used for a lithium ion battery. And it can utilize also for gel electrolytes, such as a dye-sensitized solar cell. The gelling agent of the present invention or the gel produced thereby is used in industrial fields including processing fields such as paints, inks, lubricants, agriculture, fisheries, cosmetics, pharmaceuticals, fibers, resins, polymers, rubbers, metals, etc. Can also be used.

In the case of an electrolyte gel, an ionic substance that is generally soluble in an organic liquid, such as LiClO ₄ , LiPF ₆ , Li (CF ₃ SO ₂ ) ₂ N, LiBF ₃ , LiCF ₃ SO _3, etc. in the case of a lithium ion battery. It is preferable to dissolve an ionic substance in an organic solvent and add the gelling agent of the present invention to the gel to form a gel. Of course, organic ionic liquids such as N, N, N-trialkyl-N- (alkoxyalkyl) ammonium bis (trifluoromethanesulfonyl) imide itself or a mixture obtained by dissolving them in a nonionic organic solvent can also be suitably used.

Production of Compound (c) According to the following chemical reaction formula, compound (b) is first produced from compound (a), and then compound (c) is produced from compound (b).

化合物（ｂ）の合成
化合物（ａ）２ｇのＴＨＦ（テトラヒドロフラン）溶液に１．２当量のトリエチルアミンおよび１．０当量のＣ_８Ｆ_１７Ｃ_２Ｈ_４Ｉを加え，２４時間還流した。その後，１Ｎ塩酸を加え，エーテルで抽出し，水（２回），食塩水で洗浄後，硫酸マグネシウムで乾燥した。溶媒を留去し，残渣をシリカゲルカラムクロマトグラフィーにより精製し，化合物（ｂ）を得た。（７．８０ｇ，収率８７％）
化合物（ｂ）；^１ＨＮＭＲ（ＣＤＣｌ_３）δ＝２．３３（２Ｈ，ｍ），２．９９（２Ｈ，ｍ），５．２０（１Ｈ，ｓ），６．８１（２Ｈ，ｄ，Ｊ＝８．９Ｈｚ），７．３１ （２Ｈ，ｄ，Ｊ＝８．９Ｈｚ）ｐｐｍ．
ｍｐ＝９７℃
ＩＲ（ＫＢｒ）＝ν＝１１４５，１２０３，１２４０（ＣＦ_２）ｃｍ^−１，３４００（Ｏ−Ｈ）ｃｍ^−１

化合物（ｃ）の合成
化合物（ｂ）０．５ｇの３−ペンタノン溶液に１．０当量の１−ブロモテトラデカンと１．５当量の炭酸カリウムを加え，２０時間還流した。反応溶液に析出する沈殿を濾別し，濾液の溶媒を留去し，シリカゲルカラムクロマトグラフィーにより精製し，化合物（ｃ）を得た。（０．５ｇ，７６％）
ｍｐ＝６５℃
ＩＲ（ＫＢｒ）＝１１４７，１２０１，１２４４，２９１７ｃｍ^−１
化合物（ｃ）； ^１ＨＮＭＲ（２７０ＭＨｚ，ＣＤＣｌ_３）δ＝０．８８（３Ｈ，ｔ，Ｊ＝６．８Ｈｚ），１．２２−１．４５（２２Ｈ，ｍ），１．７８（２Ｈ，ｑｕｉｎ，Ｊ＝６．６Ｈｚ），２．３３（２Ｈ，ｍ），２．９９（２Ｈ，ｍ），３．９４（２Ｈ，ｔ，Ｊ＝６．８Ｈｚ），６．８６（２Ｈ，ｄ，Ｊ＝８．９Ｈｚ），７．３６（２Ｈ，ｄ，Ｊ＝８．９Ｈｚ）ｐｐｍ．

ゲル化能
上記化合物（ｃ）を、有機溶媒に添加し、昇温することにより溶解し、生成した溶液を常温に戻すことによりゲル化するかどうか観察することにより、ゲル化能を測定した。本実施例で試みた有機溶媒は、プロピレンカーボネート、メタノール、オクタノール、アセトニトリル、ＤＭＦ、オクタン、シクロヘキサン、である。上記化合物（ｃ）は、これらの有機溶媒を５重量％程度以下で、ゲル化することができた。

Synthesis of Compound (b) To a solution of 2 g of Compound (a) in THF (tetrahydrofuran) was added 1.2 equivalents of triethylamine and 1.0 equivalent of C ₈ F ₁₇ C ₂ H ₄ I, and the mixture was refluxed for 24 hours. Then, 1N hydrochloric acid was added, extracted with ether, washed with water (twice) and brine, and dried over magnesium sulfate. The solvent was distilled off, and the residue was purified by silica gel column chromatography to obtain compound (b). (7.80 g, yield 87%)
Compound (b): ¹ HNMR (CDCl ₃ ) δ = 2.33 (2H, m), 2.99 (2H, m), 5.20 (1H, s), 6.81 (2H, d, J = 8.9 Hz), 7.31 (2H, d, J = 8.9 Hz) ppm.
mp = 97 ° C
IR (KBr) = ν = 1145, 1203, 1240 (CF ₂ ) cm ⁻¹ , 3400 (O—H) cm ⁻¹

Synthesis of Compound (c) 1.0 equivalent of 1-bromotetradecane and 1.5 equivalent of potassium carbonate were added to 0.5 g of 3-pentanone solution of Compound (b), and the mixture was refluxed for 20 hours. The precipitate precipitated in the reaction solution was filtered off, the solvent in the filtrate was distilled off, and the residue was purified by silica gel column chromatography to obtain compound (c). (0.5g, 76%)
mp = 65 ° C
IR (KBr) = 1147, 1201, 1244, 2917 cm ⁻¹
Compound (c): ¹ HNMR (270 MHz, CDCl ₃ ) δ = 0.88 (3H, t, J = 6.8 Hz), 1.22-1.45 (22H, m), 1.78 (2H, quin) , J = 6.6 Hz), 2.33 (2H, m), 2.99 (2H, m), 3.94 (2H, t, J = 6.8 Hz), 6.86 (2H, d, J = 8.9 Hz), 7.36 (2H, d, J = 8.9 Hz) ppm.

Gelation ability The above-mentioned compound (c) was added to an organic solvent, dissolved by raising the temperature, and the gelation ability was measured by observing whether the resulting solution was gelled by returning it to room temperature. The organic solvents tried in this example are propylene carbonate, methanol, octanol, acetonitrile, DMF, octane, cyclohexane. The compound (c) was able to gel these organic solvents at about 5% by weight or less.

  The compound (b) could not be dissolved in an organic solvent.

Minimum gelation concentration The minimum gelation concentration (wt%) of the compound (c) at room temperature is as follows.
DMF (0.69), methanol (0.70), acetonitrile (1.0), 1-octanol (3.0), propylene carbonate (3.5), cyclohexane (4.0), octane (5.2) ), N, N-diethyl-N-methylone- (2-methoxyethyl) ammonium bis (trifluoromethanesulfonyl) imide (5,0)

Claims (5)

An organic liquid gelling agent comprising an aromatic compound having a perfluoroalkyl group represented by the following chemical formula 1

(Where
The group C _m F _{2m + 1} is a perfluoroalkyl group, m is a natural number from 6 to 12;
The group (CH ₂ ) is a methylene group, p is the number of methylene groups, and a natural number of 0 or 1 to 4;
The group S is a sulfur atom;
The group Ar is a substituted or unsubstituted divalent aromatic group having 5 to 30 nuclear atoms;
The group O is an oxygen atom;
The group R is a saturated or unsaturated monovalent hydrocarbon group having 1 to 20 carbon atoms. )   The gelling agent according to claim 1, wherein the aromatic group Ar is a phenylene group, a biphenylene group or a naphthylene group. An aromatic compound having a hydroxyl group and a thiol group of the following chemical formula 2 is reacted with a halogenated compound having a perfluoroalkyl group of the following chemical formula 3 to produce an aromatic compound having a hydroxyl group and a perfluoroalkyl group of the following chemical formula 4, The method for producing a gelling agent according to claim 1 or 2, comprising reacting the product with a halogenated hydrocarbon.

(The meaning of the symbols in the formula is the same as in the chemical formula 1. The group X is a halogen atom reactive with the thiol group)   The gel formed by gelatinizing an organic liquid with the gelatinizer of any one of Claims 1-2.   The gel of claim 4, wherein the gel is an electrolyte gel.