JP6368466B2 - Method for producing fluorosulfonylimide package - Google Patents

Description

  The present invention relates to a method for producing a package in which fluorosulfonylimide is subdivided with good stability.

  Fluorosulfonylimide is useful as an electrolyte, an additive to a fuel cell electrolyte, a selective electrophilic fluorinating agent, a photoacid generator, a thermal acid generator, a near-infrared absorbing dye, an antistatic agent, a reaction catalyst, etc. It is known (for example, Patent Document 1).

  Fluorosulfonylimide is easily hydrolyzed to generate hydrofluoric acid. Hydrofluoric acid is a strong acid and may damage the storage container. In addition, since the presence of water has an adverse effect in battery applications and the like, the amount of water in the ionic compound must be reduced as much as possible.

  As a result of the study by the present inventors, it was found that an ionic compound having a fluorine atom such as fluorosulfonylimide can be stored with good storage stability when packaged with a packaging material having a metal layer after reducing the water content, Already filed (Patent Document 2).

International Publication No. 2009/123328 Pamphlet JP 2013-91524 A

  By the way, when the present applicant manufactures and sells fluorosulfonylimide, a small-scale package such as a 5-kg package of fluorosulfonylimide or a 2.5-kg package is required for reasons of handling or equipment. I found out. However, when the fluorosulfonylimide is actually produced in a plant, for example, it is generally synthesized at a scale of 10 kg or more per batch and stored in a storage container. In order to sell, it has become necessary to subdivide.

  However, fluorosulfonylimide is a compound that has a high molecular polarity due to the strong electron withdrawing property of fluorine atoms and is very easy to absorb moisture, and the battery using moisture-absorbed fluorosulfonylimide may deteriorate its performance. . For this reason, conventionally, subdivision was performed in a dry room having a supply air dew point of −50 ° C. or lower. However, this dry room is expensive and difficult to use during commercial production. That is, it is necessary to increase the number of dry rooms in order to manufacture a larger number of small-scale packages, but in an expensive dry room, the product cost increases. In addition, if subdivision work is performed in a dry room with a supply air dew point of -50 ° C. or lower, the dew point in the room is too low and static electricity is generated, and fluorosulfonylimide adheres to the package and the workability deteriorates. was there.

  Therefore, in the present invention, ascertaining what kind of atmosphere the fluorosulfonylimide does not absorb moisture, subdividing the fluorosulfonylimide under such an atmosphere, and finding a method for producing a small-scale package, The issue was to improve the workability by suppressing the generation of static electricity.

  The present invention that has solved the above problems is a packaging in which the content is smaller than the storage container from the storage container in which the fluorosulfonylimide represented by the following general formula (I) is stored in an atmosphere having a dew point of −25 ° C. or less. A method for producing a fluorosulfonylimide package comprising subdividing fluorosulfonylimide into a container.

(In formula (I), M represents an organic or inorganic cation, X represents fluorine or a fluoroalkyl group having 1 to 6 carbon atoms.)
Further, the present invention includes a fluorosulfonylimide package packaged by the above-described production method.

  In the present invention, since it has been found that fluorosulfonylimide hardly absorbs moisture in an atmosphere having a dew point of −25 ° C. or lower, it becomes possible to perform subdivision in a cheaper dry room and suppress rebound to product cost. did it. In addition, by working in a higher dew point atmosphere than before, it was possible to suppress the generation of static electricity and improve workability.

  The manufacturing method of the package of the present invention has an inner volume smaller than that of the storage container from the storage container in which the fluorosulfonylimide represented by the general formula (I) is stored in an atmosphere having a dew point of −25 ° C. or less. The fluorosulfonylimide is subdivided into a packaging container.

  As confirmed in the examples described later, in an atmosphere having a dew point of −19.9 ° C., the moisture content of fluorosulfonylimide is 1865 ppm in 1 hour, far exceeding the normally allowable moisture content of 1000 ppm. However, in an atmosphere with a dew point of −24.9 ° C., the moisture content of fluorosulfonylimide was almost unchanged from that before exposure. Therefore, in the present invention, the subdivision is performed under an atmosphere having a dew point of −25 ° C. or lower. In addition, it is preferable that this dew point is an actual measured value of the dew point in the vicinity where the fluorosulfonylimide is exposed (where subdivision work is performed). However, it is difficult to measure the dew point where subdivision work is being performed. However, the present inventor has confirmed that the dew point near the operator's hand (where subdivision work is performed) is almost the same as the exhaust dew point from the dry room, and the exhaust dew point is -25 ° C or lower. If so, it is within the scope of the present invention. In addition, when the dew point where the subdivision work is being performed can be calculated by simulation, if the calculated value is −25 ° C. or less, it is within the scope of the present invention.

  As above-mentioned, in the manufacturing method of the package body of this invention, it subdivides in an atmosphere with a dew point of -25 degrees C or less. Any dry room may be selected as long as such an atmosphere can be formed. Various dry rooms are sold by each company. Dry room specifications, taking into account the number of workers required, whether or not an automatic subdivision device is used (the increase in dew point is reduced because the operator's work time is reduced), the size of the required dry room, etc. Can be determined. In the case of a dry room of the same size, the price can be suppressed to about 1/4 compared with a dry room having a supply air dew point of −50 ° C. or lower.

  The storage container before subdivision stores about 10 to 100 kg of fluorosulfonylimide, but before subdivision, the storage container is also placed in an atmosphere with a dew point of -25 ° C or lower. In addition, as described in Patent Document 2, fluorosulfonylimide is preferably stored at a moisture content of 1000 ppm or less.

  In the present invention, fluorosulfonylimide is subdivided into packaging containers having an internal volume of 10 kg or less, for example, 10 kg, 5 kg, 2.5 kg, 1 kg, 500 g, 250 g, 100 g, 50 g, 20 g, 10 g, 5 g, 1 g. The subdivision may be performed by an operator or an automatic subdivision apparatus may be used.

  The packaging container containing the subdivided fluorosulfonylimide is preferably formed from a packaging material including at least one metal layer. This metal layer suppresses intrusion of moisture from the outside. As the metal layer, an aluminum layer and / or a stainless steel layer is preferable. When the packaging material is a flexible laminate, a laminate having an aluminum layer is preferable, and a sealable bag formed from a laminate in which both sides of the aluminum layer are protected with a resin film is used as a packaging container. preferable. When the packaging material is not flexible, for example, a container such as a stainless steel drum can can be used.

  In the case of flexible packaging materials, usable resin films include polyolefins such as polyethylene and polypropylene; polyesters such as polyethylene terephthalate and polybutylene terephthalate; nylons; polystyrenes and the like. When the packaging material is a laminate including an aluminum layer, it may be composed of any number of layers, and three or more layers are preferable.

  Although the total thickness as a laminated body is not specifically limited, 50 micrometers-200 micrometers are preferable, and about 5 micrometers-20 micrometers are preferable among these aluminum layers. If the aluminum layer is too thin, the film strength may decrease and pinholes may occur, and if it is too thick, the flexibility of the film will decrease and it will be difficult to handle. The production of the above laminate includes a method of attaching a resin film to an aluminum foil through an adhesive as appropriate, a method of laminating the resin on the aluminum foil while extruding the resin, depositing aluminum on the resin film, and further laminating the resin film. The method etc. are mentioned, It does not specifically limit. Moreover, as a method for sealing these laminates, it is preferable to use a chuck formed in advance in a bag and further use means such as heat sealing or ultrasonic welding.

  From the viewpoint of moisture proofing, it is preferable to use a plurality of bags, and a dry inert gas or dry air may be filled between them or a vacuum may be used. Further, the container in direct contact with the fluorosulfonylimide is not limited to a bag, and a glass or resin container may be used. In such a case, in order to avoid moisture absorption of fluorosulfonylimide, it is necessary to put a glass or resin container in a bag made of a laminate having the metal layer. Examples of the resin that can be used for the resin container include fluororesin, polyethylene, polypropylene, polystyrene, polycarbonate, nylon, polyester (polyethylene terephthalate, etc.), and may be a laminate of two or more resins.

  In addition, a package protected by a plurality of bags can be further stored and transported in a drum can, a cardboard box, a plastic case, etc., or the bag may be damaged from the outside and the fluorosulfonylimide will absorb moisture. This is a preferred embodiment. Such an embodiment is also included in the package of the present invention.

  At the time of subdivision work, workers wear masks and gloves to avoid moisture absorption of fluorosulfonylimide. In order to avoid moisture absorption due to moisture generated from the wrist or the like, a glove that covers up to the shoulder is preferable. In addition, in order to avoid deterioration of battery performance due to foreign matter contamination, it is necessary to maintain a clean degree of class 100,000 or less by providing a partition at a work place or restricting the number of workers.

  The package of this invention points out the thing of the state by which the fluoro sulfonylimide was put into the packaging container by the said method. In order to prevent moisture from entering from the outside, the package of the present invention can suppress the moisture absorption of fluorosulfonylimide, and can store and transport the fluorosulfonylimide in a state almost immediately before subdivision.

  In order to prevent hydrolysis or thermal decomposition of fluorosulfonylimide, the package of the present invention is desirably stored or transported at a relatively low temperature, preferably stored (transferred) at 50 ° C. or less, more preferably 40 ° C. Hereinafter, it is more preferable to store (transfer) at 30 ° C. or lower. When the temperature exceeds 50 ° C., the progress of hydrolysis and thermal decomposition is accelerated. Therefore, it is preferable to perform storage and transport in extreme heat (especially in a car) or in a tropical region while cooling to 50 ° C. or less.

[Fluorosulfonylimide]
The compound used for the manufacturing method of the package of the present invention is a fluorosulfonylimide represented by the following general formula (I).

(In formula (I), M represents an organic or inorganic cation, X represents fluorine or a fluoroalkyl group having 1 to 6 carbon atoms.)

  These fluorosulfonylimides are useful as battery electrolytes, but have high hygroscopicity and are suitable for applying the production method of the present invention.

  X is fluorine or a fluoroalkyl group having 1 to 6 carbon atoms. When X is fluorine, the above formula (I) shows a bis (fluorosulfonyl) imide salt, and when X is a fluoroalkyl group, it becomes an N- (fluorosulfonyl) -N- (fluoroalkylsulfonyl) imide salt. . “Fluoroalkyl” means an alkyl group having 1 to 6 carbon atoms in which one or more hydrogen atoms are substituted with fluorine atoms. For example, a fluoromethyl group, a difluoromethyl group, a trifluoromethyl group. Group, fluoroethyl group, difluoroethyl group, trifluoroethyl group, pentafluoroethyl group and the like are included. Among these, X is preferably a fluorine atom, a trifluoromethyl group, or a pentafluoroethyl group.

As the organic cation, an onium cation is preferable. As the onium cation, general formula (II); L ⁺ -Rs (wherein L represents C, Si, N, P, S or O. R is the same or different, and represents a hydrogen atom, a fluorine atom, Or when it is an organic group and R is an organic group, these may be bonded to each other, s is 2, 3 or 4, and is a value determined by the valence of the element L. The bond represented by R may be a single bond or a double bond.

  The “organic group” represented by R means a group having at least one carbon atom. The “group having at least one carbon atom” only needs to have at least one carbon atom, and may have another atom such as a halogen atom or a hetero atom, a substituent, or the like. Good. Specific examples of the substituent include an amino group, an imino group, an amide group, a group having an ether bond, a group having a thioether bond, an ester group, a hydroxyl group, an alkoxy group, a carboxyl group, a carbamoyl group, a cyano group, and a disulfide. Group, nitro group, nitroso group, sulfonyl group and the like.

  Specific examples of the onium cation represented by the general formula (II) include the following general formula:

(Wherein R is the same as in general formula (II)) is preferred. Such onium cations may be used alone or in combination of two or more. Among these, the following onium cations are preferable.

  (1) The following general formula:

One of nine heterocyclic onium cations represented by

  (2) The following general formula:

One of five types of unsaturated onium cations represented by

  (3) The following general formula:

1 type of 10 types of saturated ring onium cations represented by these.

In the general formula, R ^{1 to} R ¹² are the same or different and are a hydrogen atom, a fluorine atom, or an organic group, and in the case of an organic group, these may be bonded to each other.

(4) R is hydrogen, C ₁ alkyl group -C _8, aryl group having C ₆ -C ₁₂ or C ₇ -C ₁₃ chain onium cations aralkyl group,. Among them, those in which L is N in the general formula (II) are preferable.

For example, tetramethylammonium, tetraethylammonium, tetrapropylammonium, tetrabutylammonium, tetraheptylammonium, tetrahexylammonium, tetraoctylammonium, triethylmethylammonium, methoxyethyldiethylmethylammonium, trimethylphenylammonium, benzyltrimethylammonium, benzyltributylammonium Quaternary ammoniums such as benzyltriethylammonium, dimethyldistearylammonium, diallyldimethylammonium, 2-methoxyethoxymethyltrimethylammonium, tetrakis (pentafluoroethyl) ammonium, trimethylammonium, triethylammonium, tributylammonium, Tertiary ammonium such as ruammonium, dimethylethylammonium and dibutylmethylammonium, secondary ammoniums such as dimethylammonium, diethylammonium and dibutylammonium, methylammonium, ethylammonium, butylammonium, hexylammonium and octylammonium Examples include primary ammoniums, N-methoxytrimethylammonium, N-ethoxytrimethylammonium, N-propoxytrimethylammonium, and ammonium compounds such as NH ₄ . Among these exemplified chain onium cations, preferred chain onium cations are ammonium, trimethylammonium, triethylammonium, tributylammonium, triethylmethylammonium, tetraethylammonium and diethylmethyl (2-methoxyethyl) ammonium.

  Among the onium cations of the above general formulas (1) to (4), preferred are the following general formulas:

(Wherein R ^{1 to} R ¹² are the same as above), and the chain onium cation of (4) above. R ^{1 to} R ¹² are a hydrogen atom, a fluorine atom, or an organic group, and examples of the organic group include a linear, branched, or cyclic saturated or unsaturated hydrocarbon group having 1 to 18 carbon atoms, fluorine Group etc. are preferable, More preferably, they are a C1-C8 saturated or unsaturated hydrocarbon group and a fluorocarbon group. These organic groups are hydrogen atom, fluorine atom, nitrogen atom, oxygen atom, sulfur atom, amino group, imino group, amide group, ether group, ester group, hydroxyl group, carboxyl group, carbamoyl group, cyano group, sulfone. A functional group such as a group or sulfide group may be contained. More preferably, R ^{1 to} R ¹² have one or more of a hydrogen atom, a fluorine atom, a cyano group and a sulfone group. When two or more organic groups are bonded, the bond may be formed between the main skeleton of the organic group, or between the main skeleton of the organic group and the functional group described above, or It may be formed between the functional groups.

  When M in the formula (I) is an inorganic cation, an alkali metal ion or an alkaline earth metal ion is preferred. Examples of the alkali metal include Li, Na, and K, and examples of the alkaline earth metal include Ca and Mg. A more common compound is lithium fluorosulfonylimide where M is Li.

  Hereinafter, the present invention will be described more specifically with reference to experimental examples.However, the present invention is not limited by the following experimental examples, but may be appropriately modified within a range that can meet the purpose described above and below. Of course, it is possible to implement them, and they are all included in the technical scope of the present invention.

Experimental example 1
A dew point meter is installed at three locations (supply air 1, work location, exhaust) in a glove box equipped with a dry air line (supply air 1), a humidification line (supply air 2), and an exhaust line. The transition was monitored on time. The balance between supply air 1 and supply air 2 was adjusted, and the work place dew point was adjusted to a predetermined dew point. After confirming that the work place dew point was sufficiently stable, a bag of lithium bis (fluorosulfonyl) imide (LiFSI) with a moisture content of 16 ppm previously sealed in an aluminum laminate bag and placed in the work place in the glove box Opened and spread evenly and thinly at the work place. Thus, LiFSI exposed under a predetermined dew point was collected in a predetermined time, and the moisture content was measured with a Karl Fischer coulometric titrator (AQ-2000; manufactured by Hiranuma Sangyo Co., Ltd.).

Experimental example 2
A dry room with a design dew point of −35 ° C. manufactured by Seibu Giken Co., Ltd. was operated from the previous day and sufficiently dried. The dew point before work at the place where the subdivision work was performed was -79 ° C. When two workers entered the room, the dew point at the work place rose to -44 ° C. In the dry room, a storage container storing 20 kg of LiFSI was placed in advance. Lami Zip (registered trademark; produced by Nippon Nihonsha) AL-24 (34 cm × 24 cm × 7 cm stand type; 12 μm polyethylene terephthalate / 15 μm adhesive polyethylene / 7 μm aluminum foil / 20 μm) LiFSI was weighed with a 2.5 kg electronic balance using a resin cup into a bag composed of a five-layer laminated film made of polyethylene for adhesion / polyethylene of 60 to 80 μm, with a chuck). After closing the chuck, the upper end of the lami zip was heat-sealed twice to produce a small package. This package was put into a large size Lami Zip AL-30L (42 cm × 30 cm × 6 cm), and the upper end was heat-sealed twice and sealed. During the work, LiFSI did not adhere to the packaging bag due to static electricity. When the moisture content of LiFSI was measured with a Karl Fischer coulometric titrator (AQ-2000; manufactured by Hiranuma Sangyo Co., Ltd.), there was no change before and after the work.

  In the present invention, since it has been found that fluorosulfonylimide hardly absorbs moisture in an atmosphere having a dew point of −25 ° C. or lower, it becomes possible to perform subdivision in a cheaper dry room and suppress rebound to product cost. did it. In addition, by working in a higher dew point atmosphere than before, it was possible to suppress the generation of static electricity and improve workability. Therefore, the packaging body obtained by this invention is useful as a distribution | circulation form of the ionic compound etc. of various electrochemical devices.

Claims (3)

In an atmosphere having a dew point of −44 ° C. or more and −25 ° C. or less, from a storage container in which a fluorosulfonylimide represented by the following general formula (I) is stored, to a packaging container having a smaller content than the storage container, A process for producing a fluorosulfonylimide package, which comprises subdividing fluorosulfonylimide.
(In formula (I), M represents an organic or inorganic cation, X represents fluorine or a fluoroalkyl group having 1 to 6 carbon atoms.) The method for producing a fluorosulfonylimide package according to claim 1, wherein the packaging container is formed from a packaging material including at least one metal layer.   A package of fluorosulfonylimide, which is packaged by the production method according to claim 1 or 2.