JP2002184463A - Polymer structure, ionic conductor and method of manufacturing polymer structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a polymer structure and an ionic conductor with low electric resistance and an improved electrode efficiency. SOLUTION: The polymer structure contains a polar functional group and an ion-interactive functional group and forms a spiral shape through intramolecular interaction. The ionic conductor is obtained by dispersing an electrolyte compound in the polymer structure. Preferably, the polymer structure has not less than one or two monomer units represented by the general formula 1: wherein R1 is a polar functional group; R2 is an asymmetric atom; R3 is an ion-interactive functional group; R4 is hydrogen atom or a group of a compound; and R5 is either nonexistent or a group of a compound, with R4 being preferably a flame-retardant functional group or a cationic functional group.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an ionic conductor, and more particularly, to an ionic conductor having improved electrical resistance and electrode efficiency.

[0002]

2. Description of the Related Art As batteries for portable electronic devices such as portable telephones and portable information terminals, approximately 2% of nickel-cadmium storage batteries are used.
A nickel-metal hydride storage battery having twice the energy density has been developed, and a lithium-ion secondary battery has been developed which further exceeds the energy density of the nickel-metal hydride storage battery.

However, all of these batteries use a liquid electrolyte, and must be hermetically sealed in a metal can or the like in order to prevent liquid leakage. Was. Particularly, in a lithium ion secondary battery, an organic electrolyte is used because of high reactivity between lithium and water, and there is a problem in safety. In addition, various mechanisms must be provided in the battery as a countermeasure for overcharging and discharging, which has been an obstacle to thinning the battery.

As a secondary battery capable of solving this problem,
Attention has been focused on a polymer electrolyte battery using a solid polymer as an electrolyte. The polymer electrolyte battery has high safety without fear of liquid leakage, electrolyte solution combustion, and the like. In addition, since an electric can is not used, the degree of freedom in shape design is high. Furthermore, since the batteries need only be packaged in an aluminum laminate pack, the thickness and weight can be reduced. For these reasons, a polymer electrolyte battery having a solid electrolyte is suitable for batteries of electronic devices and the like, and various research and development are being actively conducted.

However, the all-solid-state polymer electrolyte battery has an unsolved problem. One of them is that the electric resistance is large, so that the electric energy is largely lost when incorporated into a target system. As a technique for reducing electric resistance, Japanese Patent Application Laid-Open Nos. 10-60210 and 10-67849 disclose a polymer electrolyte having a 5-membered ring carbonate as a functional group.

However, since the motion of the polymer chain is random and the ionic conduction path is not predetermined, the ionic conductivity interacts with the lone pair of oxygen in the randomly oscillating molecular chain. Therefore, a technique for further reducing electric resistance is desired.

Further, since the polymer electrolyte has no affinity for the negative electrode, the polymer electrolyte causes crystallization at the negative electrode interface, and the electrode reaction efficiency between the polymer electrolyte and the negative electrode material decreases. The point is a problem.

Further, when a battery is manufactured using a conventional polymer electrolyte membrane using a polyethylene oxide structure, even if the battery experiences any abnormality, an abnormal current or an abnormality can be obtained by reducing the amount of ions transmitted. The function of cutting off the voltage was not found in the constituent materials of the battery.

[0009]

DISCLOSURE OF THE INVENTION The present invention has been completed in view of the above problems, and has a low electric resistance, a good electrode efficiency, and a high safety and a polymer structure and an ionic conductor. The purpose is to provide.

[0010] It is another object of the present invention to provide a method for manufacturing the ionic conductor.

[0011]

SUMMARY OF THE INVENTION The present invention is characterized in that the polymer constituting the polymer electrolyte takes a helical shape, thereby establishing a path for ionic conduction. Then, the polymer is completed by paying attention to a point that the polymer collapses by taking a random coil shape, and is configured as follows in each claim.

The invention described in claim 1 is a polymer structure comprising a polar functional group and an ionic interaction functional group, and formed in a helical shape by intramolecular interaction.

The invention according to claim 2 is the polymer structure according to claim 1, further comprising a flame-retardant functional group.

The invention according to claim 3 is the polymer structure according to claim 1 or 2, further comprising a cationic functional group.

According to a fourth aspect of the present invention, in the polymer, the following formula (1):

[0016]

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Wherein R ¹ is a polar functional group, R ² is an asymmetric atom, R ³ is an ionic interaction functional group, and R ⁴
Is a hydrogen atom or a group of a compound, and R ⁵ is absent or a group of a compound.) Is a helical polymer structure having one or more monomer units.

The invention according to claim 5 is the polymer structure according to claim 4, wherein in at least one of the monomer units, R ⁴ is a flame-retardant functional group.

The invention according to claim 6 is the polymer structure according to claim 4 or 5, wherein in at least one of the monomer units, R ⁴ is a cationic functional group. .

According to a seventh aspect of the present invention, there is provided the following formula (2):

[0021]

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(Wherein R ¹ , R ² , R ³ and R ⁵ are as defined above, R ⁶ is a flame-retardant functional group, R ⁷ is a cationic functional group, and m is 5 ~ 4000, n is 2-1000,
X is 10-3000), The polymer structure of Claim 4 characterized by the above-mentioned.

According to an eighth aspect of the present invention, R ¹ is -C (=
O) NH—, R ² is a carbon atom, R ³ is an oxetane group, R ⁵ is absent, R ⁶ is a phosphazene group, R ⁷ is a 5-trimethylammonium naphthyl group, The polymer structure according to claim 7, wherein m is 60 to 2600, n is 15 to 630, and X is 230 to 2100.

According to the ninth aspect of the present invention, there is provided an image forming apparatus comprising:
2. A coil having a phase transition temperature in the range of ° C., and having a random coil shape at a temperature higher than the phase transition temperature.
9. The polymer structure according to any one of items 1 to 8.

According to a tenth aspect of the present invention, the spiral pitch is 0.01 to 6 nm.
10. The polymer structure according to any one of 9.

The polymer structure according to any one of claims 1 to 10, wherein the main chain contains 3 to 80 atoms per pitch of the spiral. It is.

The twelfth aspect of the present invention relates to the first to first aspects.
An ionic conductor comprising the polymer structure according to any one of the above items 1 and an electrolyte compound.

The invention according to claim 13 is characterized in that the reaction temperature is-
The temperature is set in the range of 70 to 40 ° C., the organic metal is 0.2 to 12% by mass relative to the total mass of the polymerization system, and the dehydrating condensing agent is 0.1 to 0.1% by mass.
The method for producing a polymer structure according to claim 7 or 8, further comprising a step of performing polymerization in the presence of 5 to 20% by mass.

The invention according to claim 14 is to dissolve or disperse the polymer in a polar solvent, and to dissolve the polymer at 60 to 120 ° C.
Hold for 00 seconds, quench the polymer at a cooling rate of -3 to -20 ° C / min, and
The method for producing a polymer structure according to any one of claims 1 to 11, comprising a step of forming a spiral shape by holding the structure for 00 seconds.

[0030]

According to the present invention configured as described above, the following effects can be obtained for each claim.

According to the first and fourth aspects of the present invention, an interaction develops inside the molecular chain of the polymer structure due to the action of the polar functional group in the polymer main chain forming the polymer electrolyte. The polymer structure has a helical shape, and the ion conduction path is clearly formed inside the helix by the action of the ionic interaction functional group, so that the ion transport amount is increased, that is, when the ionic conductor is formed. The electric resistance decreases. Also,
The helical shape of the polymer structure changes to a random shape at a high temperature, so that ionic conduction can be suppressed when the amount of ion transport becomes too large. That is, it has high security. In addition, it shows excellent characteristics in film strength, heat resistance, film forming property, flexibility, charge / discharge efficiency, and discharge rate.

According to the second and fifth aspects of the present invention, flame retardancy can be improved by introducing a flame retardant functional group into the polymer structure.

According to the third and sixth aspects of the present invention, when the polymer structure changes from a helical structure to a random structure at a high temperature, the ionic conduction is suppressed by the action of the cationic functional group. Therefore, higher safety can be provided. Further, when used as a polymer electrolyte, it has an effect of suppressing crystallization at the negative electrode, so that cycle performance is improved.

According to the present invention, the effect of flame retardancy and safety can be improved by defining the polymerization state of the unit having a flame-retardant functional group and the unit having a cationic functional group. It can be more effectively applied.

According to the eighth aspect of the invention, the effects of the first to sixth aspects can be more remarkably obtained.

According to the ninth aspect of the present invention, by defining a suitable phase transition temperature, further safety can be provided in addition to the effects of the first to eighth aspects.

According to the tenth aspect of the present invention, by defining the pitch of the spiral, the film formability and the mechanical strength can be further improved.

According to the eleventh aspect, the heat resistance can be further improved by defining the number of atoms per spiral pitch.

According to the twelfth aspect of the invention, an ionic conductor having the effects of the first to eleventh aspects can be obtained.

In the invention according to the thirteenth aspect, the reaction temperature, the amount of the added organic metal, the amount of dehydration, and the amount of the copolymer when using a monomer containing a flame retardant functional group and a monomer containing a cationic functional group are copolymerized. By defining the amount of the condensing agent, a polymer structure excellent in properties such as ionic conductivity, mechanical strength, and heat resistance can be obtained.

According to the fourteenth aspect of the present invention, by defining the holding temperature, the holding time, and the cooling rate, the ion conductivity, the adhesion to the negative electrode, the negative electrode efficiency, the heat resistance, the flexibility and the like are excellent. Polymer structure can be obtained.

[0042]

BEST MODE FOR CARRYING OUT THE INVENTION The first invention of the present application is a polymer containing a polar functional group and an ionic interacting functional group, wherein the polymer has a helical shape formed by intramolecular interaction. It is.

The polymer main chain in the present invention has many polar groups on the main chain. The polymer main chain exhibits a helical shape due to the interaction acting between the polar groups. Examples of the type of interaction include, but are not limited to, hydrogen bonding, ionic interaction, van der Waals interaction, and the like. Specifically, in a polymer, the following formula (2):

[0044]

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Wherein R ¹ is a polar functional group, R ² is an asymmetric atom, R ³ is an ionic interaction functional group, and R ⁴
Is a hydrogen atom or a group of a compound, and R ⁵ is absent or a group of a compound), and a helical polymer structure having one or more monomer units represented by the following formula: The polymer structure of the present invention may be a homopolymer composed of a single monomer unit or a copolymer composed of two or more monomer units.

In the present invention, the polar functional group means a polar functional group having a large dipole moment. Specifically, -C
(= O) NH-, -NH-, -C (= O) NHC (=
_{O) -, - SO 2 -} , - NHC (= O) O -, - C 6 H 4
-, -C (= O) O-, -C (= O) S-, -SO
_{3 -, - C 6 H 4} C (= O) O -, - NHC (= O) NH
-, - HPO ₄ -,

[0047]

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And -C (= O) NH- is particularly preferred, but is not limited thereto. Also,
An alkyl group having these functional groups may be used.

By having a polar functional group, an interaction acts between these polar functional groups inside the polymer chain. As a result, the shape of the polymer chain becomes spiral. In the polymer electrolyte using the polymer of the present invention, the inside of the helical polymer chain serves as a metal ion conduction path. Since the ion conduction path is established in this way, it is possible to increase the ion conductivity as compared with the polyethylene oxide structure which is the material of the solid polymer electrolyte membrane conventionally used for polymer batteries.

In the present invention, the asymmetric atom means a chiral (asymmetric) atom in which all four types of the functional groups are different from each other, and examples thereof include a carbon atom, a silicon atom, and a boron atom. Particularly preferred. By including such a chiral atom in the structure, a helical shape is easily formed.

In the present invention, the ionic interaction functional group is a functional group that contributes to ion conduction, and a metal ion is transmitted by the action of a lone pair or a π electron pair contained in the ionic interaction functional group. Specific examples include an oxetane group, an epoxy group, an acetamido group, a carboxyl group, an amino group, an amide group, a phenyl group, a nitrile group, a sulfonic acid group, and a phosphoric acid group. Not something.

The asymmetric atom may be bonded to a group of various compounds, and is not particularly limited. The asymmetric atom has a helical shape and takes into consideration effects such as forming a suitable path for ion conduction. Then, the size of the group of the compound is preferably from 0.2 to 3 °.

The asymmetric atom and the adjacent monomer unit are
May be directly bonded, or may be bonded through a group of the compound.
It may be. Compound groups include-(C = O)-,-
CH _TwoNH-, -CH_TwoCH_TwoO-, -CH_TwoCH_TwoCH_TwoO
-, -CH_TwoSO_Two-, -CH _TwoCH (CH_Three) O- etc.
Examples include, but are not limited to: Compound
When bonded through a group of
The number of atoms forming the main chain of the structure should be 10 or less
Preferably, the number is 4 or less, more preferably 3 or less.
Particularly preferred is below.

It is preferable that the polymer structure of the present invention further contains a flame-retardant functional group. Specifically, equation (1)
In the formula, R ⁴ is preferably a flame-retardant functional group.
In the present invention, the flame-retardant functional group is a functional group containing halogen, phosphorus, etc., which imparts flame retardancy to the polymer structure in the event that the polymer electrolyte material is encountered in a fire.
Specific examples of the flame-retardant functional group include a phosphazene group, a chloro group, a bromo group, a fluoro group, and an iodo group. A phosphazene group is particularly preferred, but is not limited thereto. By bonding such a flame-retardant functional group, ignition of the material itself can be suppressed, and fire resistance can be improved as compared with a conventional polymer electrolyte. In this case, it is not always necessary to include a flame-retardant functional group in all the monomer units constituting the polymer.

It is preferable that the polymer structure of the present invention further contains a cationic functional group. Specifically, in the formula (1), R ⁴ is preferably a cationic functional group. In the present invention, the cationic functional group refers to a functional group that is positively charged and easily becomes a cation. Also in this case, it is not always necessary to include a cationic functional group in all the monomer units constituting the polymer.

The polymer having a helical structure of the present invention can control the balance of interactions such as hydrogen bonding,
At a predetermined temperature, a phase transition phenomenon as described later can be caused to occur. When the cationic functional group is bonded to the polymer structure, the helical structure faces the outside of the helical structure, and the cationic functional group that did not hinder ion conduction at all has a random structure. In the converted polymer chain, it exhibits an exclusion effect (shutdown effect) for conducting positively charged ions. When an abnormal current occurs in the battery due to such a cationic functional group, the function of suppressing the current inside the battery is further enhanced.
It is preferable that the cationic functional group be bulky because the bulkier the cationic functional group, the stronger the shutdown effect. In this case, it is not always necessary to include a cationic functional group in all monomer units constituting the polymer.

Specific examples of the cationic functional group include 5-
Trimethylammonium naphthyl group, 2-trimethylammonium adamantyl group, 5-trimethylammonium norbornyl group, 2-trimethylammonium carbazolyl group, triphenylammonium group, 2-trimethylammonium-N-carbazolyl group, 6-trimethylammonium- 3-carboxylic acid ester-adamantyl group, 6-trimethylammonium-3-amide-adamantyl group, o- (5-norbornene-2,3-dicarboximide) -N, N, N ', N'-tetramethylurea Group, 2-methyl-3-propylbenzothiazolium group,
4-methyl-2-phenyl-1-benzopyrylium group,
1-ethyl-4-phenylpyridinium group, 3-ethyl-2-methylbenzothiazolium, ethidium group, 3,
3′-diethyloxadicarbocyanine group, triphenyl (2-pyridylmethyl) phosphonium group, 2,4,6
-Triphenylpyrylium group, tripropargylamine group and the like, and a 5-trimethylammonium naphthyl group is preferable, but the present invention is not limited to these.

When constructing a polymer structure containing both a flame-retardant functional group and a cationic functional group, the following formula (2):

[0059]

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(Wherein R ¹ , R ² , R ³ and R ⁵ are as defined above, R ⁶ is a flame-retardant functional group, R ⁷ is a cationic functional group, and m is 5 ~ 4000, n is 2-1000,
X is 10 to 3000). In addition, m, n, and X are average values, and can be measured by using NMR and elemental analysis together.

If the flame-retardant group is insufficient, flame retardancy cannot be effectively imparted. Therefore, from this viewpoint, m is preferably 5 or more, more preferably 60 or more, and particularly preferably 360 or more. preferable. Further, since the density of the cationic functional group decreases when the flame retardant group is present in excess, m is preferably 4000 or less, more preferably 2600 or less, and particularly preferably 1800 or less.

In order to provide a sufficient shutdown effect when the polymer structure assumes a random shape at the time of an abnormality,
n is preferably 2 or more, more preferably 15 or more, and particularly preferably 80 or more. Also, if the density of the cationic functional groups in the polymer structure is too high, the hydrophobic-hydrophobic interaction becomes stronger than the interaction that forms the helical structure on the main chain, and as a result, the main chain forms a helical structure Since there is a possibility that it will not occur, it is preferably 1,000 or less, more preferably 630 or less, and particularly preferably 470 or less.

X is preferably 10 or more in order to sufficiently increase the molecular weight of the polymer structure and enhance the film forming property.
It is more preferably at least 450, and particularly preferably at least 450. If the molecular weight is too large, the flexibility of the polymer structure may be reduced.
00 or less, more preferably 2100 or less, and particularly preferably 1680 or less.

The polymer structure of the present invention preferably undergoes a conformational transition when the helical shape exceeds a predetermined temperature and becomes a random shape. By random transition, as described above, the conductivity can be reduced by the action of the cationic functional group, the battery temperature can be suppressed from rising due to the abnormal voltage and the abnormal current, and the safety can be improved. I do.

In order to lower the temperature at which a random shape is formed (phase transition temperature), it is necessary to weaken the interaction in the polymer structure, so that the helical structure is partially broken, and as a result, the ionic conductivity is reduced. May drop. For this reason,
The phase transition temperature is preferably 120 ° C. or higher, and more preferably 150 ° C. or higher. Further, if the phase transition temperature is higher than necessary, the interaction between the functional groups constituting the helical structure becomes too strong, resulting in an increase in the brittleness of the film. More preferably, there is.

It is preferable to define the spiral pitch. In the present invention, the helical pitch is a unit of translation regularity of the helical structure, and when a point on the main chain of the helical polymer is drawn as a starting element, a straight line is drawn in the direction of extension of the polymer structure. Is defined as the distance from the starting element to the ending element when the element encountered for the first time on the polymer main chain is the ending element. If the pitch is too small, the affinity for the solvent may decrease, and as a result, the film-forming property may decrease. Further, the crystallinity of the polymer main chain becomes too large, and the mechanical strength of the solid polymer electrolyte membrane may be reduced. For this reason, the spiral pitch is 0.01 n
m or more, more preferably 0.08 nm or more. Conversely, if the pitch is too large, the conducting ions may go out of the helical structure and the ionic conductivity may be reduced. In addition, the crystallinity may be excessively reduced, and the mechanical strength of the ion conductive membrane may be reduced when the membrane is prepared. For this reason, 6 nm or less is preferable, and 2.5 n
m is more preferable.

It is preferable to define the number of atoms contained in the main chain of the polymer per one pitch of the spiral. When the number of atoms is too small, the interaction between the functional groups that form the helix becomes small, and the diameter of the helix structure easily changes with temperature. Therefore, the number of atoms is preferably 3 or more, and more preferably 12 or more. More preferred. Further, if the number of atoms is too large, the interaction between the functional groups forming the helix becomes large, and the diameter of the helix structure becomes too small. As a result, it becomes impossible to secure a diameter for generating ionic conduction. , 45 or less.

If the number of functional groups contained in the polymer per one pitch of the spiral is too small, the fluctuation of the polymer chain becomes small and the flexibility may be reduced. Is more preferable. Also,
If the amount is too large, the ions excessively enter the inside of the helical polymer structure, and repulsion occurs between the ions. As a result, the ion conductivity of the polymer electrolyte may be reduced. For this reason,
The number is preferably 30 or less, more preferably 18 or less.

The second invention of the present application is an ionic conductor comprising the above-described polymer structure and an electrolyte compound. The ionic conductor of the present invention can be applied to an electrolyte of a battery such as a lithium polymer secondary battery. When using the polymer structure according to the present invention as an ion conductor, it is necessary to disperse an electrolyte compound in the polymer structure. The electrolyte compound refers to a compound having electric conductivity in a polymer electrolyte, and specifically, LiN (CF ₃ SO ₂ ) ₂ , LiN
(C ₂ F ₅ SO ₂ ) ₂ , LiN (CF ₂ SO ₃ ) ₂ , LiP
F ₆ , LiCF ₃ SO ₃ , LiBF ₄ , LiPF ₆ , LiN
H ₂ , LiF, LiCl, LiBr, LiI, LiC
N, LiClO ₄ , LiNO ₃ , C ₆ H ₅ COOLi, Na
Cl, NaBr, NaF, NaI, NaClO ₄ , Na
CN, and the like, but the present invention is not limited to these. The electrolyte compound is preferably dispersed uniformly in the polymer electrolyte, and may be dispersed directly in the ionic conductor in a solid state or may be mixed after being dissolved in a solvent.

When the mixture concentration of the electrolyte compound is reduced, the ion concentration in the polymer electrolyte is reduced, and the ion conductivity may be reduced. On the other hand, if it is too large, the dispersion of the ionic compound becomes uneven, and the mechanical strength of the solid polymer membrane may be reduced. Therefore, the mixing concentration of the polymer electrolyte is 0.1 to 80% by mass based on the mass of the ion conductor.
, Preferably 20 to 60% by mass.

FIG. 18 is a schematic sectional view of one embodiment of the polymer electrolyte battery according to the present invention. In the polymer electrolyte battery, a positive electrode 2, an ion conductor (polymer electrolyte membrane) 3, and a negative electrode 4 are sequentially stacked, and a positive electrode current collector 1 and a negative electrode current collector 5 are disposed on both surfaces of the stacked body, respectively. Further, it has a structure in which an exterior material 6 is provided outside the positive electrode current collector and the negative electrode current collector. As the configuration of the battery, various known techniques can be appropriately used except that the polymer according to the present invention is used as an electrolyte material.

As the positive electrode material, LiMn ₂ O ₄ , LiCo
O ₂ , Li ₂ Cr ₂ O ₇ , Li ₂ CrO ₄ , and the like,
Examples of the negative electrode material include carbon, lithium metal, and the like, and the shape of the negative electrode material includes a flat plate, a corrugated plate, a rod, and a powder.
Fibrous, helical, and fibril shapes can be mentioned, but are not limited to those exemplified.

The polymer battery of the present invention can be packaged with an outer package. At this time, as the type of the exterior material, an aluminum foil, an aluminum-deposited organic film or the like can be used. Examples of the material of the organic film include, but are not limited to, polyethylene, polypropylene, polyethylene terephthalate, polybutylene terephthalate, nylon, and polyethylene tetrafluorate.

The polymer battery according to the present invention can be used as a single cell composed of positive and negative electrodes and an ionic conductor, or can be used as a stacked cell in which cells are stacked or an assembled battery. At this time, a resin film or a metal foil can be interposed between the unit cells.

The resin film may be made of high-density polyethylene, low-density polyethylene, polypropylene, polyethylene tetrafluorate, polybutylene tetrafluorate, polyvinylidene chloride, polyvinyl chloride,
-Nylon, 6,12-nylon, polytetrafluoroethylene, perfluoroalkylsulfonic acid, polypyrrole, polystyrene, polystyrene-butadiene copolymer, and the like, but are not limited thereto.

The types of metal foil include copper, aluminum, iron,
Nickel, magnesium, zinc, silicon, iron oxide, copper oxide, and the like. Of these, a single material may be used, or composite formation by vapor deposition or lamination may be performed.
However, the invention is not limited to these materials.

The shape of the battery may be a flat surface, a cylinder, a spiral, a ribbon, a tape, a rectangular parallelepiped, a cube, a cone, a sphere, a rod, or the like, but the present invention is not limited to these shapes. The method for producing a polymer structure according to the present invention will be described in detail.

In order to obtain the copolymer represented by the above formula (2), a dehydration condensation reaction can be used. In the dehydration condensation reaction, the reaction temperature is set in a temperature range of -70 to 40 ° C, and the organic metal is contained in an amount of 0.2 to 12% by mass based on the total mass of the polymerization system.
It is preferable that the dehydrating condensing agent is present in an amount of 0.5 to 20% by mass. In the present invention, the total mass of the polymerization system refers to the total mass of the solvent, organic metal, dehydrating condensing agent and the like used in the polymerization.

The reaction temperature is preferably -70 to 40 ° C. in order to improve the tensile strength of the ionic conductor.
50 to 30C is more preferable.

In the polymerization, the organic metal added for chemically bonding R ¹ and R ² is used in an amount of 0% with respect to the total mass of the polymer polymerization system in order to promote the formation of a polar functional group and to favorably form a helix. .2% by mass or more,
It is more preferable to add 3% by mass or more. On the other hand, if the addition amount is too large, the stirring efficiency decreases, and the polymerization molecular weight does not increase. As a result, the heat resistance when the ionic conductor is formed may be reduced. Therefore, the amount is preferably 12% by mass or less, more preferably 8% by mass or less based on the total mass of the polymer polymerization system.

Specific examples of the organometallics that can be mixed include tin (II) diacetate, tin (IV) tetraacetate,
Tin (II) ethylhexanoate, tin oxalate (I
I), tin (II) trifluoromethanesulfonate, bis (2,4-pentanedionato) tin dichloride, bis (2,4-pentanedionato) nickel, bis (2
4-pentanedionato) molybdenum dioxide, bis (2,4-pentanedionato) manganese, bis (8-quinolinolato) zinc (II), bis (8-quinolinolato)
Copper (II), bis (tri-n-butyltin), bis (trifluoro-2,4-pentanedionato) copper, bis (trifluoro-2,4-pentanedionato) cobalt, bis (trifluoro) -2,4-pentanedionato) manganese and bis (trifluoro-2,4-pentanedionato) nickel, but the present invention is not limited thereto.

If the amount of the added dehydrating condensing agent is too small, the degree of polymerization does not increase, so that the density of the helical portion does not increase. Accordingly, ion conductivity may be reduced. For this reason, it is preferably at least 0.5% by mass, more preferably at least 2% by mass, based on the total mass of the polymer polymerization system. On the other hand, if the content is too large, the density of the region having high crystallinity in the molecular chain increases, and the mechanical strength of the ion conductor may decrease. For this reason, it is preferably 20% by mass or less, more preferably 14% by mass or less, based on the total mass of the polymer polymerization system.

Specific examples of the dehydrating condensing agent include dicyclohexylcarbodiimide, 1,1'-carbonyldiimidazole, diethylphosphorocyanide, N, N '
-Diisopropylcarbodiimide, N-ethoxycarbonyl-2-ethoxy-1,2-dihydroquinoline, 1-ethyl-3- (3-dimethylaminopropyl) carbodiimide hydrochloride, N-ethyl-N'-3-dimethylaminopropylcarbodiimide and the like However, it is not limited to these.

The polymerization reaction can be advanced by stirring. If the stirring is too slow, the ion conductive functional groups may be irregularly arranged, and the ion conductivity may be reduced. For this reason, 1000 times / min or more is preferable, and 2500 times / min is more preferable. On the other hand, if it is too early, the polymer chains may be cut, the molecular weight may be reduced, and the film strength may be reduced. Therefore, 6000 operations / min
The following is preferable, and 3200 times / min is more preferable.

In the polymerization reaction, ultrasonic irradiation can be used without stirring. If the frequency of the ultrasonic wave used at this time is too low, the number of collisions of molecules decreases, so that no polymerization reaction occurs and the molecular weight does not increase. Therefore, the membrane strength of the polymer electrolyte membrane decreases. For this reason, 10,000 Hz or more is preferable, and 20,000 Hz or more is more preferable. On the other hand, if it is too high, the crystallinity of the polymer chain may be destroyed, and the film-forming property may be reduced during film formation. Therefore, the frequency is preferably 150,000 Hz or less, more preferably 120,000 Hz or less.

If the irradiation time of the ultrasonic wave is too short, polymerization is not promoted, a portion lacking a helical shape is generated in the polymer chain, and there is a possibility that a phase transition phenomenon from a helix to a random structure may not be exhibited. The time is preferably 0.5 minutes or more, more preferably 5 minutes or more, because the shutdown mechanism at the time of abnormality is lost. In addition, if the length is too long, the portion where the heat-resistant functional group is dissociated is emitted, and the heat resistance of the film may be reduced.
120 minutes or less are preferable, and 40 minutes or less are more preferable.

As the solvent for the polymerization reaction, a polar solvent can be used. At this time, if the concentration of the monomer dissolved or dispersed is too small, the degree of polymerization does not increase, so that the strength may decrease when the ionic conductor is manufactured. For this reason, the amount of the monomer added is preferably 0.01% by mass or more based on the total mass of the polymerization system used.
8% by mass or more is more preferable. Also, if too much, the viscosity of the solution or dispersion increases, resulting in inefficient stirring,
The molecular weight may be in an inappropriate range, and the film-forming property of the film may be reduced. For this reason, it is preferably 25% by mass or less, more preferably 13% by mass or less, based on the total mass of the polymerization system used. Specific examples of the polar solvent include, but are not limited to, tetrahydrofuran, and it is preferable to appropriately select the polar solvent depending on the reaction conditions used.

Although the preferred method for synthesizing the copolymer represented by the formula (2) has been described above, when synthesizing another polymer such as synthesizing a homopolymer, various known techniques are used. Can be used.

Hereinafter, a method for forming a high-molecular polymer into a spiral shape will be described. That is, the polymer is dissolved or dispersed in a polar solvent,
Hold for 2 seconds, quench the polymer at a cooling rate of -3 to -20C / min, and 10 to 300 in the range of -50 to -10C.
By holding for 2 seconds, it is possible to suitably form a spiral shape.

If the temperature of the preheating is too low, the polymer chains are rapidly cooled in a random state, so that no helical structure is formed and the ionic conductivity of the ionic conductor may be reduced. Therefore, the temperature is preferably 60 ° C. or higher, more preferably 80 ° C. or higher. On the other hand, if the height is too high, the diffusion motion of the polymer main chain becomes large, so that the diameter of the helix becomes too large. As a result, the ionic conductivity of the ionic conductor may be reduced. For this reason, the temperature is preferably 120 ° C. or lower.
It is more preferable that the temperature is not higher than 00 ° C.

If the holding time of the preheating is too long, the polymer chains are rapidly cooled without giving any degree of freedom to the movement of the polymer chains. For this reason, 10 seconds or more are preferable, and 60 seconds or more are more preferable. On the other hand, if the length is too long, the polymer main chain is oxidized and decomposed to cause a reduction in molecular weight, which may lower the efficiency of the negative electrode. Therefore, the time is preferably 300 seconds or less, and more preferably 220 seconds or less.

After preheating, rapid cooling is preferred.
If the cooling rate during quenching is too slow, the interaction between polar groups does not occur, and the polymer shape retention force decreases. as a result,
When a solid polymer film is manufactured, the heat resistance may be reduced. From this viewpoint, it is preferable to perform rapid cooling at -3 ° C / min or more, more preferably -6 ° C / min.
On the other hand, if it is too rapid, the interaction between the polar groups becomes too large, the conformational force increases, and the polymer main chain becomes rigid. For this reason, when manufacturing a solid polymer film, flexibility may be reduced. From this viewpoint, -20 ° C /
A rapid cooling of not more than min is preferable, and -12 ° C / min is more preferable.

If the temperature reached after quenching is too low, the flame-retardant functional groups will aggregate, and the brittleness of the polymer electrolyte membrane may increase. For this reason, the temperature is preferably −50 ° C. or higher, more preferably −30 ° C. or higher. On the other hand, if it is too high, no interaction between the polar groups occurs, so that no helical shape is formed, and the ionic conductivity may be reduced. For this reason, the temperature is preferably −10 ° C. or lower, more preferably −20 ° C. or lower.

If the holding time after quenching is too short, the pitch of the polymer structure becomes long, and the ion conductivity may be reduced. For this reason, 10 seconds or more are preferable, and 90 seconds or more are more preferable. On the other hand, if the length is too long, the interaction between polar groups becomes too large, and the phase transition function may be lost. Therefore, the time is preferably 300 seconds or less, and more preferably 240 seconds or less.

After the polymer polymerization, the polymer may be irradiated with far-infrared rays before the quenching operation, and then the quenching operation may be performed. If the wavelength of the far-infrared ray irradiated at this time is too short, the polymer is excessively heated and is decomposed and precipitated, causing phase separation even when mixed with the supporting electrolyte. In comparison, the degree of adhesion to the negative electrode may be reduced. Therefore, 300
cm ^-1 or less, more preferably 200 cm ^-1 or less. On the other hand, if the length is too long, the polymer is not sufficiently heated, and the polymer chain does not extend. Therefore, the quenching effect is lost and the helical structure is not exhibited, so that the ion conductivity may be reduced. For this reason, it is preferably at least 20 cm ⁻¹ ,
m- ¹ or more is more preferable.

[0096]

<Example 1> 2-Amino-2-phosphonic chloride trimer-2-oxetane in a 300 ml separable round bottom glass reaction vessel equipped with a cooling pipe, a nitrogen introducing pipe, and a rotary magnetic stirrer. Take 8.6 g (0.02 mol) of acetic acid (molecular weight: 430), and then add 2-amino-2-triphenyl (2-pyridylmethyl)
9.68 g (0.02 mol) of phosphonium chloride-2-oxetaneacetic acid (molecular weight: 484) was added, and 130 ml of tetrahydrofuran was added as a solvent. After adding 5.1 g of LiN (CF ₃ SO ₂ ) as a supporting electrolyte, the reaction solution was stirred at 2,000 times / min.
3.10 g of ethyl-N'-3-dimethylaminopropylcarbodiimide (molecular weight: 155) were added. further,
After addition of 0.5 g of tin (II) 2-ethylhexanoate, the reaction vessel was cooled to -20 ° C and reacted for 4 hours.
After the reaction, the reaction vessel was heated to 90 ° C., allowed to stand for 120 seconds, and then rapidly cooled to −30 ° C. at a cooling rate of −10 ° C./min. Then, after leaving still for 240 seconds, vacuum drying was performed for 6 hours. After drying, the obtained ion conductor was dissolved in 120 ml of N, N-dimethylformamide to obtain a polymer electrolyte (ion conductor) solution. The polymer electrolyte solution is cast on a glass plate, heated on a hot plate at 100 ° C. for 2 hours, and then dried in a vacuum drier at 90 ° C. for 8 hours to obtain a solid electrolyte polymer film (ion conductor film). Was formed. The obtained polymer electrolyte membrane was cut into a circular shape having a diameter of 18 mm, and sandwiched between two cylindrical stainless steel electrodes having a diameter of 18 mm and a thickness of 5 mm.
Inside a 50 mm long Teflon (registered trademark) cylinder, a 20.5 mm outside diameter stainless steel screw was screwed in from both sides to make contact with the two cylinders sandwiching the above-mentioned polymer film (block type electrode). The ion conductivity E2 was calculated from the impedance measurement result when a block electrode was connected to the Solartron Impedance Analyzer S-1260 and an alternating current was passed from the high frequency side to the low frequency side. Similarly, as a comparative example, a polymer electrolyte membrane was manufactured using polyethylene oxide (molecular weight: 20,000), and the ionic conductivity E1 was measured. Based on these, the relative values of the ionic conductivity were defined as follows. The results are shown in FIG.

[0097]

(Equation 1)

Example 2 The affinity between the polymer electrolyte membrane and the negative electrode was evaluated by the following method. When casting the polyelectrolyte solution produced in Example 1, a width of 20 was used instead of a glass plate.
After casting on a carbon plate having a thickness of 200 mm, a length of 200 mm and a thickness of 5 mm, a film was formed. After peeling off the end of the carbon plate and the polymer film by 50 mm between the upper and lower chucks of the tensile tester, the maximum peel strength S2 (Mpa) of the polymer film when 20 mm was sandwiched and pulled. Similarly, peel strength S using polyethylene oxide (molecular weight: 20,000)
1 was rated. Using these values, the affinity for the negative electrode was defined as follows. The results are shown in FIG.

[0099]

(Equation 2)

Example 3 The polymer electrolyte membrane of Example 1 was cut to a width of 10 mm and a length of 150 mm, and was set on a tensile tester to determine the tensile strength F2 when pulled at a distance between chucks of 100 mm. Next, the tensile strength of the polymer electrolyte membrane manufactured using polyethylene oxide (molecular weight: 20,000) was defined as F1 (Mpa). Using these values, the tensile strength ratio was defined as follows. The results are shown in FIG.

[0101]

(Equation 3)

Example 4 5 mg of the polymer electrolyte obtained in Example 1 was sampled, and TG-DTA was measured in an air atmosphere. The thermal decomposition onset temperature at that time was defined as T2 (° C.), and polyethylene oxide (molecular weight 2000
The thermal decomposition onset temperature measured using (0) was defined as T1 (° C.), and the heat resistance was defined as follows. The results are shown in FIG.

[0103]

(Equation 4)

<Example 5> In Example 1, the film was peeled off over time while the heating time was changed in the operation of completing drying and crosslinking on a hot plate, and the tensile strength was measured. When measuring the dependency between the heating time and the tensile strength of the film, the time required for the tensile strength of the film to reach 1 Mpa was L2, and polyethylene oxide (molecular weight 2
0000) was defined as L1 and the time required to reach the specified strength was defined as follows. The results are shown in FIG.

[0105]

(Equation 5)

Example 6 A polymer electrolyte membrane produced in Example 1 was cut into a square of 5 cm × 5 cm, a smooth metal plate was laid on the membrane, and a weight of 20 g was placed on the metal plate.
At this time, the sinking depth of the weight was measured using a laser displacement meter. The thickness reduction distance of the film at this time was defined as D2 (mm).
Similarly, the thickness reduction distance measured using polyethylene oxide (molecular weight: 20,000) was defined as D1, and the flexibility was defined as follows. The results are shown in FIG.

[0107]

(Equation 6)

Example 7 The polymer electrolyte membrane obtained in Example 1 was cut into a size of 30 cm × 30 cm and a thickness of 100 μm. This film was fixed, and a burner flame was approached, contacted for 30 seconds to remove the flame, extinguished the flame, and measured the maximum diameter H1 of the plane burned at that time. Similarly, assuming that the maximum diameter of the burned plane of the polymer electrolyte membrane containing polyethylene oxide as a main raw material is H2, the flame retardancy is defined as follows. The results are shown in FIG.

[0109]

(Equation 7)

Example 8 After adding 20% of carbon fine powder to the polymer electrolyte solution produced in Example 1, it was cast on a copper foil. Then, the polymer electrolyte solution produced in Example 1 was cast. Furthermore, LiMn ₂
A positive electrode material containing 30% by mass of O ₄ and a polymer mixed solution were cast. After the aluminum foil was covered from above, these laminates were heated on a hot plate at 100 ° C. for 1 hour. After packaging the laminate with an aluminum laminate film, it was sealed by heating. The obtained all-solid-state lithium polymer battery was mounted on a charge / discharge test apparatus, and charge / discharge characteristics were observed. In addition, a battery was prepared using the same material for the positive and negative electrodes using conventionally used polyethylene oxide, and a charge / discharge test was performed (Comparative Example). The result is shown in FIG. The discharge rate characteristics of the battery according to the present invention were better than those of the battery using the conventional polyethylene oxide.

Example 9 The cycle performance of repeating the charge / discharge operation was compared between the polymer battery according to the present invention and the conventional battery (Comparative Example) manufactured in Example 8. The result is shown in FIG. The cycle performance of the battery according to the present invention was able to prevent crystallization at the negative electrode, and was better than the cycle performance of the conventional battery.

<Example 10> In accordance with the method of Example 1, the flame retardancy when the number of repetitions m in the equation (2) was changed was measured. FIG. 4 shows the results. Number of repetitions m is 5
The flame retardancy of the polymer electrolyte membrane of ~ 4000 was 1.0 or more.

<Example 11> In accordance with the method of Example 1, the degree of flexibility when the number of repetitions n in the equation (2) was changed was measured. FIG. 5 shows the results. Number of repetitions n is 2
The flexibility of the polymer electrolyte membrane of ~ 1000 was 1.0 or more.

<Example 12> According to the method of Example 1, the film forming degree when the degree of polymerization X in the formula (2) was changed was measured. FIG. 6 shows the results. Polymerization degree X is 10 to 30
The polymer electrolyte membrane of No. 00 became 1.0 or more.

<Example 13> A polymer electrolyte membrane having a different temperature when the polymer structure undergoes a phase transition from a helical shape to a random structure was prepared according to the method of Example 1, and the ionic conductivity was measured. did. FIG. 7 shows the result. The relative value of ion conductivity of the polymer electrolyte membrane having a phase transition temperature of 120 to 200 ° C. was 1.0 or more.

Example 14 According to the method of Example 1, a polymer electrolyte membrane was prepared in which the pitch of the helical polymer was changed, and the mechanical strength was measured. FIG. 8 shows the result. The tensile strength ratio of the polymer electrolyte membrane having a pitch of 0.01 to 6 nm was 1.0 or more.

Example 15 A polymer electrolyte membrane having a different number of atoms per pitch was manufactured in accordance with the method of Example 1, and the change in heat resistance was examined. FIG. 9 shows the result. The heat resistance of the polymer electrolyte membrane having 3 to 80 atoms per pitch became 1.0 or more.

<Example 16> In the production of the ionic conductor of Example 1, the tensile strength ratio when the reaction temperature of the dehydration condensation reaction was changed was measured. The results are shown in FIG. When the reaction temperature was -70 to 40 ° C, the tensile strength ratio became 1.0 or more.

Example 17 In the production of the ionic conductor of Example 1, the heat resistance was measured when the addition concentration of the organic metal was changed. The results are shown in FIG. When the additive concentration of the organic metal was 0.2 to 12% by mass, the heat resistance was 1.0 or more.

<Example 18> In the production of the ionic conductor of Example 1, a change in the relative value of ionic conductivity when the concentration of the dehydrating condensing agent was changed was examined. As shown in FIG. When the concentration of the dehydrating condensing agent was 0.5 to 20% by mass, the ionic conductivity relative value was 1.0 or more.

<Example 19> In the production of the ionic conductor of Example 1, the relative value of the ionic conductivity when the preheating temperature was changed was measured. FIG. 13 shows the results. When the preheating temperature is 60 to 120 ° C., the relative value of ionic conductivity is 1.
It became 0 or more.

<Example 20> In the method for producing an ionic conductor of Example 1, the affinity of the negative electrode was measured when the preheating holding time was changed. FIG. 14 shows the results. When the holding time of the preheating is 10 to 300 seconds, the negative electrode affinity is 1.
It became 0 or more.

<Example 21> In the method for producing an ionic conductor of Example 1, the degree of flexibility when the cooling rate was changed was measured. FIG. 15 shows the results. -3 to -20C / m
When the cooling rate was in, the flexibility was 1.0 or more.

<Example 22> In the method for manufacturing an ionic conductor of Example 1, the relative value of ionic conductivity when the attained temperature after the quenching operation was changed was measured. FIG. 16 shows the results. The ionic conductivity relative value was 1.0 or more in the range of -50 to -10C.

<Example 23> In the method for producing an ionic conductor of Example 1, the relative value of the ionic conductivity when the holding time after quenching was changed was measured. The results are shown in FIG.
The ionic conductivity relative value became 1.0 or more between 10 and 300 seconds.

[Brief description of the drawings]

FIG. 1 is a graph showing various characteristics of a polymer electrolyte membrane according to the present invention.

FIG. 2 is a graph illustrating a discharge rate characteristic of the battery according to the present invention.

FIG. 3 is a graph illustrating the cycle performance of the battery according to the present invention.

FIG. 4 is a graph showing the relationship between the number of repetitions m and the flame retardancy.

FIG. 5 is a graph showing a relationship between the number of repetitions n and flexibility.

FIG. 6 is a graph showing the relationship between the degree of polymerization X and the degree of film formation.

FIG. 7 is a graph illustrating a relationship between a phase transition temperature and a relative value of ionic conductivity.

FIG. 8 is a graph comparing the relationship between pitch and tensile strength ratio.

FIG. 9 is a graph showing the relationship between the number of atoms per pitch and the heat resistance.

FIG. 10 is a graph showing the relationship between the reaction temperature of the dehydration condensation reaction and the tensile strength.

FIG. 11 is a graph showing the relationship between the added concentration of an organic metal and the heat resistance.

FIG. 12 is a graph showing the relationship between the concentration of a dehydrating condensing agent and the relative value of ion conductivity.

FIG. 13 is a graph showing a relationship between a preheating temperature and a relative value of ion conductivity.

FIG. 14 is a graph showing the relationship between preheating holding time and negative electrode affinity.

FIG. 15 is a graph showing a relationship between a cooling rate and flexibility.

FIG. 16 is a graph showing a relationship between a cooling ultimate temperature and a relative value of ion conductivity.

FIG. 17 is a diagram showing the relationship between the retention time after quenching and the relative value of ion conductivity.

FIG. 18 is a cross-sectional view of one embodiment of a polymer battery using the ion conductor according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Positive electrode collector 2 Positive electrode 3 Ion conductor (polymer electrolyte membrane) 4 Negative electrode 5 Negative electrode current collector 6 Exterior material

Claims (14)

[Claims] 1. A polymer structure comprising a polar functional group and an ionic interaction functional group, wherein the helical shape is formed by intramolecular interaction. 2. The polymer structure according to claim 1, further comprising a flame-retardant functional group. 3. The polymer structure according to claim 1, further comprising a cationic functional group. 4. In a polymer, a compound represented by the following formula (1): Wherein R ¹ is a polar functional group, R ² is an asymmetric atom, R ³ is an ionic interaction functional group, R ⁴ is a hydrogen atom or a compound group, and R ⁵ is absent Or a helical polymer structure having one or more monomer units represented by the following formula: 5. The polymer structure according to claim 4, wherein in at least one of the monomer units, R ⁴ is a flame-retardant functional group. 6. The polymer structure according to claim 4, wherein in at least one of the monomer units, R ⁴ is a cationic functional group. 7. The following formula (2): (Wherein R ¹ , R ² , R ³ and R ⁵ are as defined above,
⁶ is a flame-retardant functional group, R ⁷ is a cationic functional group, m is 5 to 4000, n is 2 to 1000, and X is 10 to 10.
5. The method according to claim 4, wherein the number is 3000.
3. The polymer structure according to item 1. 8. R¹Is -C (= O) NH-, and R^TwoIs
A carbon atom, R ^ThreeIs an oxetane group, and R^FiveExists
Without, R⁶Is a phosphazene group;⁷Is 5-trimethyl
A luammonium naphthyl group, m is 60-2600
Where n is 15 to 630 and X is 230 to 210
8. The polymer structure according to claim 7, wherein 0.
body. 9. The method according to claim 1, having a phase transition temperature in the range of 120 to 200 ° C., and forming a random coil at a temperature higher than the phase transition temperature. Molecular structure. 10. The polymer structure according to claim 1, wherein the pitch of the helix is 0.01 to 6 nm. 11. The polymer structure according to claim 1, wherein the main chain contains 3 to 80 atoms per spiral pitch. 12. An ionic conductor comprising the polymer structure according to any one of claims 1 to 11 and an electrolyte compound. 13. The reaction temperature is set in a temperature range of −70 to 40 ° C., and the amount of the organic metal is set to 0.2 to 100% based on the total mass of the polymerization system.
The method for producing a polymer structure according to claim 7 or 8, comprising a step of polymerizing in the presence of 12% by mass and 0.5 to 20% by mass of a dehydrating condensing agent. 14. A polymer is dissolved or dispersed in a polar solvent and kept at 60 to 120 ° C. for 10 to 300 seconds.
The polymer is quenched at a cooling rate of −20 ° C./min.
The method for producing a polymer structure according to any one of claims 1 to 11, further comprising a step of forming a helical shape by maintaining the temperature in a range of 0 to -10 ° C for 10 to 300 seconds.