WO2007032202A1

WO2007032202A1 - Novel compound having two-phase state and process for producing the same

Info

Publication number: WO2007032202A1
Application number: PCT/JP2006/316898
Authority: WO
Inventors: Hiroshi Sakaguchi; Akiko Kawai
Original assignee: National Institute Of Advanced Industrial Science And Technology
Priority date: 2005-09-12
Filing date: 2006-08-28
Publication date: 2007-03-22
Also published as: JP4899168B2; JPWO2007032202A1

Abstract

[PROBLEMS] To provide: a compound or lithium carboxylate which has a two-phase state having a regulated crystal form and which can be used in various applications; and a process for producing the same. [MEANS FOR SOLVING PROBLEMS] A compound which has two melting points and, at a temperature between the two melting points, is in a two-phase state in which a crystalline state coexists with a liquid state; or an organic lithium oxide compound having a structure which comprises a flat ionic crystal constituted of lithium and oxygen and organic groups which each consists mainly of an alkyl chain and are chemically bonded to the crystal; or a lithium carboxylate compound which is a flat or flaky crystal and is obtained by dissolving either a combination of a carboxylic acid and lithium oxide or hydroxide or a lithium carboxylate synthesized beforehand in a mixed solvent comprising an alcohol and water and then causing precipitation. The process for lithium carboxylate compound production comprises heating either a combination of a carboxylic acid and lithium oxide or hydroxide or an existing lithium carboxylate in a mixed solvent comprising an alcohol and water to dissolve them and then gradually cooling the solution to precipitate flat or flaky crystals.

Description

Novel compound having two-phase state and method for producing the same

Technical field

[0001] The present invention relates to a novel compound having a two-phase state and a method for producing the same, and particularly relates to a novel lithium carboxylate having a two-phase state and a method for producing the same.

Background art

[0002] Conventionally produced industrially produced carboxylic acid metal salts are lubricants, greases, dispersants, water repellents in industrial fields such as plastics, pigments, cements, ceramics, metal processing, lubricating oils and cosmetics. Have been used as release agents, desiccants, catalysts, stabilizers, bactericides, and the like.

[0003] Until now, carboxylic acid metal salts are produced by synthesizing carboxylic acid power, and at the same time, precipitated into powder, lump, or gel, or dried and solidified while volatilizing the solvent. It contains many impurities, and it was impossible to control the crystal form and size. Thus, unlike many other chemical products, carboxylic acid metal salts have only been used for industrial products whose crystal form is unknown. (Refer to Non-Patent Documents 1 to 4.) As a result, carboxylic acid metal salts are amphiphiles due to their molecular structure. It has been limited to a narrow range.

This is because, despite the fact that the metal carboxylate is an amphiphile, it has been virtually impossible to obtain high-purity crystals with controlled crystal morphology because of its extremely low solubility in water. caused by.

[0004] Among metal carboxylates, lithium carboxylate has been used exclusively for the use of lithium stearate (octadecanoate) having 18 carbon atoms for the reasons described above. The lithium acid was in the form of powder, gel, or lumps whose crystal form was unknown. Therefore, lithium carboxylate with a controlled crystal form is considered to have very unique and unique properties, but its properties are still not fully utilized. Seems to be limited.

Non-Patent Document 1: Tokiyuki Yoshida, Shinichi Shindo, Tadayoshi Ogaki, Satoshi Ide, “Characteristics and Applications of Metal Soap”, Koshobo, October 5, 1988 Non-Patent Document 2: Arai Yokichi, Matsushima Shozo, "Zanzen Metal Ishibuchi" 3rd edition, Sangyo Tosho Co., Ltd., September 1, 1927

Non-Patent Document 3: R'C 'by MEROTRA and R. Bohra, "METAL CARBOXYLATES", ACADEMIC PRESS (1983) Non-Patent Document 4: Claré Markley ( Klare S. Markley), `` Fats and Oils '', A ¾enes of Monographs Fattty Acids Their and hemistry, Properties, Production, and Uses, Interscience Publishers, Inc., New York (1961), Chapter 8: Salt VIII Salts of Fatty Acids, Klare S. Markley

Disclosure of the invention

Problems to be solved by the invention

[0005] In the present invention, in lithium carboxylate, a high-purity crystal having a controlled crystal form is obtained, and at the same time, the organic group portion is freely changed, so that the use temperature of a lubricant or the like that has been conventionally used, Systematic changes in viscosity, etc. to greatly expand the practical possibilities of applications, and provide lithium carbonate that can be used for various applications that have never been considered before and a method for producing the same It is for the purpose.

Means for solving the problem

[0006] In order to solve the above problems, a carboxylic acid metal salt having an unknown crystal form is obtained in the process of obtaining a carboxylic acid metal salt by reacting a carboxylic acid with a metal oxide or a metal hydroxide. It is necessary to dissolve completely in the solvent, and then to precipitate the high purity carboxylic acid metal salt as crystals with decreasing temperature. Furthermore, the solvent used can be easily separated from the precipitated carboxylic acid metal salt crystals, and can be washed by easily dissolving in water or a commonly used organic solvent, or low boiling point so that the crystals do not remain after drying. It is necessary to be. Therefore, it was found that the solvent used for the synthesis of the carboxylic acid metal salt is desirably water-soluble. Furthermore, the obtained high-purity metal carboxylate crystals were analyzed and found to be a compound having a novel two-phase structure.

[0007] The present invention has been completed based on these findings, (1) a compound having two melting points and having a two-phase state in which a crystalline state and a liquid state coexist at a temperature between both melting points;

(2) Lithium atom and oxygen atomic energy Organic oxidation characterized by having a structure formed by chemical bonding of a planar ion crystal composed of an organic group mainly composed of an alkyl chain on both sides of the plane. Lithium compounds,

(3) A plate-like or scale-like crystal deposited after dissolving carboxylic acid and lithium oxide or lithium hydroxide in a mixed solvent of alcohol and water. The lithium carboxylate compound of (1) or (2),

(4) The present invention described in (1) or (2) above, wherein the existing lithium carboxylate is a plate-like or scaly crystal that is precipitated after dissolving in a mixed solvent of alcohol and water. Lithium carbonate compounds,

(5) Carboxylic acid and lithium oxide or lithium hydroxide are heated and dissolved in a mixed solvent of alcohol and water, and then slowly cooled to form plate-like or scaly crystals. (1) to (3) above, wherein any one of the methods for producing a lithium carboxylate compound,

(6) The existing lithium carboxylate is dissolved by heating in a mixed solvent of alcohol and water, and then precipitated as plate-like or scaly crystals by slow cooling (1) (2) or (4) provides a method for producing any one of the lithium carboxylate compounds.

The invention's effect

According to the present invention, the physical properties can be systematically changed by systematically changing the alkyl chain length, even with extremely high crystallinity, high purity, constant carbon chain length, and therefore constant physical properties. It is possible to produce a series of lithium carboxylate crystals and various organic lithium oxide compounds. These lithium carboxylate crystals and organic lithium oxide compounds systematically change physical properties such as lubricants, greases, dispersants, water repellents, mold release agents, desiccants, catalysts, stabilizers, and bactericides. Can be used for a wide range of purposes. Further, according to the present invention, it is possible to obtain a very thin, highly insulating flat crystal, and it can be used as various insulating materials as a synthetic mica substitute. Furthermore, the compound of the present invention has a unique two-phase structure, and the low-temperature melting point, the crystallization temperature, and the magnitude of the enthalpy change greatly change depending on whether the number of carbon atoms in the alkyl chain is odd or even. By utilizing this, the surface properties can be controlled in a wide temperature range. Furthermore, the alkyl chain arrangement on the surface of the compound of the present invention is stable and orderly, and a much more stable laminated film than a conventional LB film can be produced very easily and with a large amount of force.

Brief Description of Drawings

[0009] [Fig. 1] The above is a C14Li (lithium tetradecanoate) flake-like crystal obtained by the present invention. 1. Og is a photograph taken with a digital camera. (Microscope) It is a photograph.

[Fig. 2] The above is a C18Li (lithium octadecanoate) flake-like crystal obtained in the example. 1. Og is a digital camera photo, and below is a SEM (scanning electron microscope) photo magnified 5000 times. It is.

[Fig. 3] The above is a photograph of a crystal of lithium octadecanoate (Acros) commercially available as a reagent. 1. The bottom is a SEM (scanning electron microscope) magnified 5000 times. It is a photograph.

[Fig. 4] The above is a digital camera photograph of 1.0 g of lithium octadecanoate provided by NOF Corporation, and the bottom is a SEM (scanning electron microscope) photograph magnified 5000 times.

FIG. 5 shows the results of single crystal X-ray structural analysis of C14Li (lithium tetradecanoate).

FIG. 6 is a diagram showing the results of measuring the low temperature side melting point and the high temperature side melting point for C08Li force C22Li.

BEST MODE FOR CARRYING OUT THE INVENTION

[0010] The lithium carboxylate crystal or organic lithium oxide compound of the present invention comprises, in a mixed solvent of alcohol and water, an organic compound mainly composed of a carboxylic acid or an alkyl chain, and lithium oxide or lithium hydroxide compound. Some are plate-like or scaly crystals which are precipitated after dissolving existing lithium carboxylate. The crystal of the present invention is preferably a crystal having a controlled crystal form. In this specification (including claims), “Crystal with controlled crystal form” means a crystal that has a distinct plate-like or flake-like crystal form rather than a powdery, gel-like, or massive precipitate. Further, it means that 90% by weight or more of lithium carboxylate is contained in the crystal after drying, preferably 95% by weight or more, more preferably 97% by weight or more.

[0011] Further, according to the present invention, a mixed solvent of alcohol and water contains an organic compound mainly composed of a carboxylic acid or an alkyl chain and lithium oxide or lithium hydroxide. The present invention provides a method for producing a lithium carboxylate crystal in which plate-like or scaly crystals are precipitated after dissolution.

Usually, when carboxylic acid and lithium oxide or lithium hydroxide are added to a mixed solvent of alcohol and water, the force to precipitate lithium carboxylate crystals immediately at room temperature is obtained in this way. The crystal is a mixture of fine powder, gel, half-scaled scale, and irregular shape.

On the other hand, in the production method of the present invention, it is necessary to carry out the reaction after completely dissolving, so that the plate-like or scale-like lithium carboxylate crystal of the present invention can be obtained for the first time. It is.

In the present invention, an alcohol and water mixed solvent (hereinafter referred to as “alcohol Z water mixed solvent”) is used as a solvent. The alcohol is preferably a lower alcohol. The higher the concentration of the lower alcohol, and the higher the alcohol concentration, the higher the solubility of lithium carboxylate at the same alcohol concentration. In the dissolution reaction, the reaction temperature required for complete dissolution varies depending on the carbon chain length of the carboxylic acid and the alcohol concentration in the solvent. Further, the concentration of lithium carboxylate in the solution can be made extremely high by increasing the alcohol concentration in the solvent. Furthermore, the shorter the carbon chain length of lithium carboxylate, the more completely it dissolves at a lower temperature. “Complete dissolution” means a dissolved state in which the entire reaction solution is colorless and transparent, and the presence of any crystal precipitates in the solution, the liquid surface, or the inner wall of the container cannot be confirmed with the naked eye.

[0013] In the method for producing a lithium carboxylate crystal or an organic lithium oxide compound of the present invention, preferably, the organic compound mainly composed of the original carboxylic acid or alkyl chain and the lithium oxide or lithium hydroxide salt are obtained. Or the existing lithium lithium carboxylate The crystals are precipitated by heating in a mixed solvent of lower alcohol and water and completely cooling, followed by cooling. Precipitated crystals can be obtained by simply filtering by a usual method, and further purified crystals can be obtained by washing with water, followed by natural drying at normal pressure, air drying, or vacuum drying.

[0014] The lithium carboxylate crystal of the present invention produced from carboxylic acid and lithium oxide or lithium hydroxide, or obtained by re-dissolving existing powdered lithium carboxylate is a plate Crystal or scaly crystal. In the present invention, the plate-like crystal means a crystal having a plate-like planar shape after precipitation that can be observed with the naked eye. Further, the thickness of each of the plate-like crystals and the scaly crystals is preferably 0.5 m or less, more preferably 0.1 l ^ m or less. In the present invention, they are deposited and formed by overlapping. .

[0015] In the present invention, the molarity of lithium carboxylate to be dissolved (or carboxylic acid when carboxylic acid and lithium hydroxide or lithium hydroxide is dissolved) and water. The ratio (lithium carboxylate: water) is preferably 1: 1000 to 50: 1000, more preferably 5: 1000 to 30: 1000.

[0016] In the present invention, the molarity of lithium carboxylate to be dissolved (or carboxylic acid when carboxylic acid and lithium hydroxide or lithium hydroxide is dissolved) and alcohol. The ratio (force lithium rubonic acid: alcohol) is preferably 1: 1 to 1: 400, more preferably 1:10 to 1: 300.

[0017] In addition, the molar ratio of alcohol: water in the alcohol Z water mixed solvent is appropriately changed depending on the type of carboxylic acid, lithium carboxylate and alcohol used. Ethanol: water 0: 1000 to 500: 1000 power is preferable , 10: 1000-300: 1000 power is even more preferred! In the case of methanol, a molar ratio of about twice that of ethanol is required, and in the case of propanol and butanols, the number of moles of 1Z2 to 1Z5 of ethanol is sufficient.

[0018] It is further desirable that the carboxylic acid in the case of the lithium carboxylate used in the present invention is a monocarboxylic acid having a straight chain or a saturated alkyl chain. The carbon number of the carboxylic acid used in the present invention is desirably 1-30. Considering the unpleasant odor peculiar to carboxylic acids having a small number of carbon atoms, corrosiveness, and the difficulty in obtaining carboxylic acids having a large number of carbon atoms, it is more preferably 8-22. More specifically, octanoic acid, nonanoic acid, decanoic acid ( (Puric acid), undecanoic acid, dodecanoic acid (uraric acid), tridecanoic acid, teradecanoic acid (myristic acid), pentadecanoic acid, hexadecanoic acid (palmitic acid), heptadecanoic acid, otadecanoic acid (stearic acid), nonadecanoic acid , Araquinic acid, heneicosanoic acid, docosanoic acid

(Behenic acid). These carboxylic acids can be used singly or in combination of two or more, but it is preferable to use one singly to obtain high purity crystals.

[0019] The alcohol used as the solvent is preferably methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, 2-methyl-1 propanol, or t-butanol. In view of safety to the human body, ease of handling, and high solubility in water, ethanol, 1 propanol, and 2-propanol are more preferable.

[0020] The reaction temperature required to deposit lithium carboxylate after synthesizing or redissolving it as high-purity crystals varies depending on the carbon chain length of the carboxylic acid and the alcohol concentration, but the carbon chain length of the carboxylic acid is short. It is so cold. In addition, the weight of crystals obtained using the alcohol concentration required for complete dissolution is 1% to 40% of the total reaction solution, and high-purity crystals are produced to such a high concentration that all the solution solidifies during precipitation. Can do. The reaction temperature is preferably 40 ° C to 170 ° C by adjusting the lithium carboxylate concentration and the alcohol concentration, and taking into consideration the safety of the reaction, the production and handling of the reaction vessel. . From the viewpoint of practicality, the reaction is more preferably carried out in the range of 40 ° C to 150 ° C.

[0021] Specifically, carboxylic acid and lithium oxide or lithium hydroxide are put into a mixed solvent of alcohol and water, and stirred while heating so as to be maintained at the above temperature to be completely dissolved. When the heating temperature exceeds the boiling point of the mixed solvent of alcohol and water, the above reaction is carried out in a sealed pressure vessel so that the mixed solvent does not evaporate.

[0022] The reaction vessel and heating method are not particularly limited, but by heating to a predetermined temperature and stirring sufficiently, the precipitated lithium carboxylate crystals, unreacted carboxylic acid, etc. The reaction solution becomes colorless and transparent, confirms that no solid matter or crystals remain on the reaction vessel wall or other attached equipment, and further heats and stirs. It is necessary to continue to completely dissolve the invisible residual crystallites.

Further, it is necessary that there is no non-uniform temperature distribution in the reaction solution and in the reaction vessel. For example, when the reaction is carried out at 120 ° C, if there is an inner wall portion that is about 2 ° C lower than that, microcrystals will form at that location and start growing, and the scale-like uniformity required by this patent Crystals cannot be obtained.

[0023] Alcohol required for complete dissolution Z The concentration of alcohol used as a water mixed solvent is that methanol requires the highest concentration, methanol, ethanol, 2-propanol, 1 propanol, t-butanol, 2-methyl-1 propanol, Effective in the order of 2-butanol and 1-butanol at low concentrations, for example, the concentration of 1-butanol in water required for complete dissolution of lithium octadecanoate at the same temperature is less than 1Z10 of methanol in water. is there.

[0024] Carboxylic acid (RCOOH) and lithium hydroxide monohydrate (LiOH · H 0) are used as starting materials.

2 is preferably 1: 1 to 1: 1.5 in terms of a molar ratio of carboxylic acid: lithium hydroxide ′ monohydrate, more preferably 1: 1 to 1: 1. Desirably, the carboxylic acid is quantitatively changed to lithium carboxylate and no unreacted carboxylic acid remains.

[0025] Lithium carboxylate having a carbon chain length of 13 or more is practically insoluble in ethanol Z aqueous solution at room temperature, but the carboxylithium group still has hydrophilicity, and the lithium carboxylate crystal is an amphiphilic substance. Therefore, the resulting scaly crystals are almost uniformly dispersed throughout the liquid rather than being precipitated at the bottom of the container. Such a precipitation form is also a standard for knowing that the target scaly crystals are obtained.

The obtained crystals can be dried, high-purity and uniform scaly crystals by filtration, washing, dehydration, and vacuum drying using ordinary glass filters, filter paper, and pure water for washing.

[0026] Mica is known to cleave in a very thin layer due to its crystal structure, and since it has a high aspect ratio, it has long been used as an insulating material. In addition, it has been used as a number of industrial materials due to its excellent properties such as excellent elasticity, heat resistance, and chemical resistance, high dielectric constant, and low thermal expansion coefficient. However, the place and amount of natural production are limited, and the composition, concentration, and distribution of mica contained in the impurities are various, and a uniform product can be obtained according to the application. Difficult is there.

On the other hand, the lithium carboxylate crystal of the present invention can be obtained as a very thin plate-like crystal having a side length of several to 30 mm, which approximates a quadrilateral at the time of crystal precipitation. Like the mica, it is cleaved thinner, and each tabular crystal is a laminate of thinner tabular crystals. When observed with a scanning electron microscope, the thickness of each flake is preferably 0.1 μm or less. In the present invention, a plate-like or scaly crystal is formed in such a state. Furthermore, as a result of X-ray diffraction, the thickness of these plate crystals varies with the length of the alkyl chain of lithium carboxylate. The minimum unit is 2ηπ! It became obvious that the thin pieces of ~ 5nm were laminated.

[0027] According to the present invention, it is possible to easily obtain a plate-like lithium salt / carboxylate crystal that is more homogeneous and has a higher purity than natural mica. Furthermore, the plate-like or scale-like lithium rubonic acid crystal of the present invention has the physical properties such as the high insulation, elasticity, heat resistance, chemical resistance, high dielectric constant, and low thermal expansion coefficient inherent to the lithium carboxylate crystal. Since it is provided, it can be used as various materials more useful than natural mica.

[0028] Further, since lithium carboxylate is an amphiphilic molecule having a hydrophilic carboxyl group and lithium, and also having an alkyl chain that is both hydrophobic and hydrophobic, it is completely dissolved in an aqueous alcohol solution by heating. After cooling, it precipitates as crystals, but in the present invention, preferably, the precipitated crystals are also uniformly dispersed throughout the reaction solution rather than being precipitated at the bottom of the reaction vessel, resulting in extremely bulky precipitation. . This means that the interaction with water as a solvent is sufficiently large as a very thin, plate-like V or scaly crystal. However, since it is an amphiphilic molecule having an alkyl chain that is hydrophobic, it can emulsify and disperse as a surfactant even though it is a crystal. Specifically, this plate-like crystal is dispersed as it is in water as it is or finely pulverized, and various oils are taken into water and mixed, that is, used as an emulsifier. be able to. Such applications are quite unlikely with conventional lithium carboxylates.

[0029] Furthermore, as a result of single crystal structure analysis by X-ray of the flat or flaky lithium carboxylate crystal of the present invention, as shown in the examples described later, the lithium carboxylate of the present invention was It was found that um has a bilayer structure in which the alkyl chains are slightly arranged on both sides of an ionic crystal plane structure composed of lithium atoms and oxygen atoms and are regularly arranged. The scaly crystal of the present invention has such a structure in which multiple layers are laminated.

This bilayer structure is completely different from conventional amphiphilic compound molecules that form molecular aggregates with the help of water molecules in water to form a lamellar structure. The corresponding part is the macroscopic ionic crystal itself, which is formed by two-dimensional bonding between lithium and oxygen. Therefore, independent of the thermal behavior of the alkyl chain, the crystalline state as an ionic crystal can be maintained at a much higher temperature.

This is also apparent from the results of observation with a variable temperature optical microscope and measurement using a differential scanning calorimeter with respect to the lithium carboxylate crystal of the present invention, as shown in the examples described later.

That is, the lithium carboxylate of the present invention is in a crystalline state (corresponding to the region indicated as “solid phase” in FIG. 6) at a temperature lower than the low-temperature melting point, both the ionic crystal part and the alkyl chain part. It can be said that it is a true crystal.

In addition, when the temperature is higher than the low-temperature melting point, only the alkyl chain part that does not change anything melts into a liquid state, and in the temperature range between the low-temperature melting point and the high-temperature melting point, The crystal part and the liquid part of the alkyl chain coexist in one crystal (corresponding to the region described as “two-phase coexistence” in FIG. 6). Such a two-phase coexistence state is obtained as a pure compound itself, so it is very stable for a long time, and when the temperature is lowered below the melting point on the low temperature side, it completely returns to the original crystalline state, and again the melting point on the low temperature side This will completely return to the two-phase state. In other words, these two states can be repeated repeatedly. Such stability is essentially different from that of artificial laminated films such as conventional lamella layers and LB films.

When heated to a temperature higher than the melting point on the high temperature side, both the alkyl chain part and the ionic crystal part melt, and the whole is in a liquid state (corresponding to the region indicated as “liquid phase” in FIG. 6). Even if the liquid thus formed is cooled again to a temperature lower than the melting point on the high temperature side, flat and scaly crystals cannot be reproduced.Therefore, macroscopically, the alkyl chains are uniformly and regularly distributed over a large area. The arranged structure cannot be reproduced. However, even in this case, the original Since the macroscopic arrangement structure is not lost because the lithium carboxylate itself is not decomposed, the plate-like and scaly crystals are formed again by the method shown in the present invention using such irregular lithium carboxylate as a raw material. It is possible to recreate it.

[0031] In the lithium carboxylate of the present invention, the temperature interval between the low-temperature side melting point and the high-temperature side melting point is very wide in any of the lithium carboxylate crystals. A coexistence state can be realized and it can be used for various industrial applications.

In addition, the low-temperature melting point of the lithium carboxylate of the present invention varies greatly depending on the carbon chain length, and it differs greatly systematically depending on whether the carbon number is even or odd. It can be used for applications in various temperature ranges.

[0032] Coexistence of a crystal part and a liquid part in a simple compound such as lithium carboxylate of the present invention was first found in the present invention, and can be found in liquid crystals and plastic crystals as reported previously. It is essentially different from the mesophase.

The existing lithium carboxylate crystals are also considered to have partially changed in this way, but the crystal system is not a uniform flat or scaly crystal. It cannot be taken out and cannot be used industrially.

[0033] In addition, there have been many attempts to produce an alkyl chain structure by arranging a surfactant and various amphiphilic compounds in a single layer or arranging them in layers. Although unstable and not satisfactory, the layered structure of alkyl chains according to the present invention realizes such a high degree of arrangement of alkyl chains in the form of crystals in a very orderly and large area. Therefore, it forms the basis for various industrial uses.

Example

Hereinafter, the present invention will be described in more detail based on examples, but the present invention is not limited thereto.

[0035] Under the reaction conditions shown in Table 1, carbonic acid (RCOOH) having a carbon number of 8 (octanoic acid) and a carbon number of up to 22 (docosanoic acid) was used as a starting material (indicated as the original acid in Table 1). Add an excess of lithium hydroxide monohydrate (LiOH.H 0) and mix ethyl alcohol (EtOH) and water (H 0).

twenty two

The reaction was carried out in the solvent as follows. [0036] Vertical cylindrical pressure-resistant glass containers having an internal volume of 1 L and 2 L were used for the reaction. The reaction vessel is composed of a Teflon ring portion that joins a vessel body and a lid with a glass sheath for temperature measurement, and is tightened with a bolt and a nut to be sealed.

The reaction vessel was placed on a hot plate, and a powerful magnet installed in the hot plate was rotated to uniformly stir the reaction solution with a vertical Teflon magnetic stirrer inserted into the vessel.

The temperature of the hot plate that heats the reaction vessel from the bottom was set to about 20 ° C higher than the reaction temperature. Furthermore, the outer periphery of the side surface of the reaction vessel was heated by surrounding it with a transparent mantle heater made of glass and incorporating nichrome wire. The temperature of the mantle heater was measured by a thermocouple inserted in the temperature measuring glass sheath and controlled by a controller.

[0037] It was confirmed that the reaction solution became colorless and transparent, and that no solids or crystals remained on the inner wall of the glass or the Teflon stirrer. Further, heating and stirring were continued for about 20 minutes to complete the reaction. Dissolved. After confirming complete dissolution, the heater and stirring were stopped and cooled slowly.

Scale-like crystals were precipitated after supercooling at a power of approximately 20 ° C to 20 ° C, depending on the carbon chain length of the lithium carboxylate produced.

[0038] After the stock solution was filtered, washing with water and filtration were repeated twice, followed by vacuum drying to produce each carbon number lithium carboxylate crystal. In Table 1, the produced lithium carboxylate is represented by CXLi (X is an integer). Here, X is the number of carbon atoms, and in the case of 12 carbon atoms lithium dodecanoate, it is expressed as C12Li. In Table 1, the values for the original acid, LiOH.H20, ethanol and water are molar ratios, and the yield is the actual amount obtained after vacuum drying with respect to the charged amount of carboxylic acid. The amount of lithium carboxylate is expressed as a molar ratio.

[0039] [Table 1] Pressure resistant 1 L container

Lithium carboxylate Original acid LiOH- H ₂ 0 Ethanol Water Reaction temperature Reaction time Purity Yield

(Molar ratio) (Molar ratio) (Molar ratio) (Molar ratio) (° C) (Time) (%) ()

C08U 10 1 1 100 1000 60 2 99 «or more 89.4

C09Li 10 1 1 100 1000 80 4.5 99% or more 76.5

C10Li 30 33 100 1000 80 3 99% or more 91.9

C1 1 Li 5 5.5 100 1000 70 1 99% or more 50.0

C12Li 5 5.5 100 1000 70 1.5 99% or more 60.8

C13Li 5 5.5 100 1000 80 1 99% or more 93.5

CHLi 10 1 1 100 1000 95 2 99% or more 97.3

C15Li 5 5 200 1000 85 2 99% or more 97.5

C16Li 10 1 1 150 1000 100 2.5 or more 90.3

C17Li 10 1 1 200 1000 105 5 9994 or higher 99.0

C18Li 2 2 300 1000 90 3.5 9994 or higher 92.4

C19Li 5 5.5 200 1000 1 10 3 99% or more 98.5

C20Li 5 5.5 200 1000 1 10 2 99% or more 99.5

C21 Li 5 5.5 200 1000 120 2.5 99X or more 98.7

C22Li 5 5.5 200 1000 120 4.5 99% or more 98.3

[0040] In each case of Table 1, the weight of the precipitated lithium carboxylate crystals is 1Z40 to 1Z3, which is the weight of the reaction solvent combined with ethanol and water. It is dominated by crystals that are solidified in pure white, and the reaction solvent is completely free from wrinkles. However, since the hydrophobicity of the crystal is high, it is not decanted! The crystal and the solvent liquid can be easily separated by filtration.

[0041] In the case of lithium carboxylates having a relatively short alkyl chain such as C08Li to C14Li, bubbles are produced during filtration, and the solubility in water and alcohol is slightly increased, so the yield is somewhat reduced. . In such a case, the yield can be reduced by preliminarily lowering the reaction solution or filtrate below room temperature, or by adding water to the reaction solution to relatively reduce the alcohol concentration and then filtering. It can be raised further.

In either case, the resulting crystals are 99% or higher in purity.

[0042] The obtained lithium carboxylate crystal is a plate-like crystal in an optical micrograph and an SEM photograph, and one plate-like crystal is thinner, and is in the form of a laminated scale having a thickness of 0.03 to 0.2 m. It was observed to consist of crystals. Figure 1 and Figure 2 show typical examples of the outer shape of the obtained C14Li (lithium tetradecanoate) and C18Li (lithium octadecanoate flaky crystals) and a 500,000 magnification photograph, respectively, using a scanning electron microscope. Show.

For comparison, photographs of commercially available lithium octadecanoate (Acros) and lithium octodecanoate provided by NOF Corporation are shown in FIGS. 3 and 4, respectively. As can be seen from these photographs, the lithium carboxylate crystal of the present invention is a scaly crystal formed by laminating flat crystals having a very large and large area. Is clearly different.

[0043] C14Li obtained in the examples was subjected to X-ray single crystal structure analysis.

The results are shown in FIG.

[0044] [Table 2]

C14Li single crystal structure analysis results

a-axis length 3.3460 nm

b-axis length 0.4906 nm

c-axis length 0.9043 nm

Οί angle 90 degrees

Angle of 97.743 degrees

角度 angle 90 degrees

Space group P21 Zc

Final R value 0.064

[0045] As a result of structural analysis, the crystal structure of the lithium carboxylate of the present invention was a typical monoclinic crystal system. However, the unit molecule of lithium tetradecanoate, CH COOLi, which was conventionally considered vaguely, , Instead of assembling and forming monoclinic crystals as molecular aggregates

13 17

It was a macroscopic ionic crystal with a planar structure composed of lithium and oxygen atoms.

That is, lithium atoms and oxygen atoms form a plate-like ionic crystal with individual molecular forces independent of each other, rather than belonging to individual molecules. This is, for example, a macroscopic ionic crystal in the same meaning as a macroscopic ionic crystal as a whole of a single crystal that is not an aggregate of individual NaCl units.

In the lithium carboxylate of the present invention, the alkyl chains are arranged in a regular manner with a slight inclination of the alkyl chain on both sides of the lithium crystal and the ion crystal plane composed of oxygen nuclear power. Each thin and flat crystal is alkyl on both sides. Covered with chains.

The scaly crystal of the present invention is formed by stacking such planar structures in layers. It was confirmed by scanning electron microscope observation.

Such a structure is revealed for the first time by the very thin flat plate-like scale crystals obtained by the method of the present invention, and the strength and characteristics of the crystal structure are sufficiently obtained industrially. It is what makes it available.

In FIG. 5, the zigzag plane partial force lithium atom and the ionic crystal portion composed of oxygen nuclear power at the center of the figure, and the alkyl chains are arranged at regular intervals on the upper and lower sides. Since the alkyl chain is fixed by bonding to the ionic crystal plane and becomes easier to move toward the tip of the chain, the carbon that forms the chain skeleton is shown as a larger ellipse toward the tip.

Alkyl chain parts are neatly arranged at low temperatures in the temperature range depending on the length of each carbon chain to form molecular crystals, but as shown in the measurement results with the following differential scanning calorimeter, At temperatures above the melting point, it enters a liquid state. At this time, the ionic crystal part does not change at all, and only the alkyl chain part becomes a liquid, but unlike a normal liquid, it is fixed to the S ion crystal surface at one end, so it fluctuates in the crystal plane. Will be.

[0047] The obtained lithium carboxylate crystal was measured with a differential scanning calorimeter. The results are shown in Table 3 and FIG.

[0048] [Table 3]

As is clear from Table 3 and Fig. 6, all of C08Li to C22Li had two distinct melting points on the low temperature side and the high temperature side. The melting point shown in Table 3 is only a part of the lithium carboxylate crystal (alkyl chain part) melting, and the melting point of the whole crystal was observed with a variable temperature optical microscope and using a differential scanning calorimeter. From the measurements, it was found that both were near 250 ° C. Further, as is apparent from the results shown in Table 3 and FIG. 6, in general, the melting point and melting enthalpy of the lithium carboxylate crystal having an odd number of carbon atoms are higher than the melting point and melting point of the adjacent lithium carbonate carboxylate having an even number of carbon atoms. It is much larger than enthalpy. That is, the crystal orientation is larger in the odd-numbered lithium carboxylate crystal. This is what has become clear for the first time by synthesizing lithium carboxylate crystals with different carbon chain lengths systematically in this way, because of the power that has never been known before.

Utilizing these differences in physical properties systematically changes the physical properties of lubricants, greases, dispersants, water repellents, mold release agents, desiccants, catalysts, stabilizers, bactericides, and various insulating materials. It can be used for a wide range of purposes.

Claims

The scope of the claims

[1] A compound having two melting points and having a two-phase state in which a crystalline state and a liquid state coexist at a temperature between both melting points.

[2] It is characterized by having a structure in which a planar ionic crystal composed of lithium atoms and oxygen nuclear power and an organic group mainly composed of an alkyl chain are chemically bonded to both sides of the plane. Organic lithium oxide compounds.

[3] A plate-like or scaly crystal which is precipitated after dissolving carboxylic acid and lithium oxide or lithium hydroxide in a mixed solvent of alcohol and water. The lithium carboxylate compound according to claim 1 or 2.

[4] The lithium carboxylate compound according to claim 1 or 2, wherein the lithium carboxylate is a plate-like or scaly crystal which is precipitated after dissolving the existing lithium carboxylate in a mixed solvent of alcohol and water. .

[5] Carboxylic acid and lithium oxide compound or lithium hydroxide compound are dissolved in a mixed solvent of alcohol and water by heating and then slowly cooled to precipitate as plate-like or scaly crystals. The method for producing a lithium carboxylate compound according to any one of claims 1 to 3, wherein the lithium carboxylate compound is produced.

[6] The existing lithium carboxylate is dissolved by heating in a mixed solvent of alcohol and water, and then slowly cooling to precipitate it as plate-like or scaly crystals. Or 5. The method for producing a lithium carboxylate compound according to any one of 4 above.