JPH06172582A - Ionically conductive polymer composition - Google Patents

Abstract

PURPOSE:To obtain the title composition which has high conductivity at room temperature and low temperatures and does not evaporate or escape even at high temperatures by incorporating a plasticizer containing a specified polyethylene glycol dialkyl ether. CONSTITUTION:A plasticizer comprising a polyethylene glycol dialkyl ether of formula I derived by terminating both the terminals of a basic skeleton comprising an ethylene oxide polymer of a degree of polymerization in the range: 4<=n<=7 with 2-4 C alkyl, allyl or cycloalkyl or a polyethylene glycol dimethyl ether derived by terminating both the terminals of a basic skeleton comprising an ethylene oxide polymer of a degree of polymerization in the range: 5<=n<=7 with methyl is added to a polymeric compound (e.g. a compound of formula III), and the obtained mixture is cured to obtain the title composition which has high conductivity at room temperature and low temperatures and which does not evaporate or escape even at high temperatures.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ion conductive polymer composition containing a plasticizer, which is used in electrolytic capacitors and the like.

[0002]

2. Description of the Related Art In recent years, with the development of industrial fields, higher performance and higher reliability of electronic devices have been demanded. In particular, electrochemical elements such as capacitors and batteries that use an electrolytic solution have many problems in terms of leakage, mounting on devices, workability, and the like, and solidification of the electrolytic solution has been conventionally considered.

Among such solid electrolytes, the ion conductive polymer has a much smaller ionic conductivity than an inorganic electrolyte, but it is lightweight, flexible, and moldable. It is attracting attention because it is superior in terms of mechanical performance.

[0004] For example, a complex of polyethylene oxide and a lithium salt (ion conductivity: at 100 ° C. to 10 ^{over 4} S / cm)
{Polymer, 14 , 586 (1973)}, diisocyanate cross-linked polymer of triol-type polyethylene oxide-metal salt complex (ionic conductivity: 10 ^-5 S / cm at 30 ° C) (JP-A-62-62)
-48716). In addition, examples of application to actual electrolytic capacitor, the siloxane - a mixture of alkylene oxide copolymer and polyethylene oxide and complexes such as an alkali metal salt (ion conductivity: at room temperature for 10 ^{over 6-10 over 5} S / cm) (JP-A-1-503425) has been reported.

However, since these materials have low ionic conductivity at room temperature, when applied to an electrolytic capacitor, the loss is large and sufficient characteristics cannot be obtained. In order to solve such a problem, it is considered to add a plasticizer such as tetraethylene glycol dimethyl ether capable of dissolving an electrolyte salt to the ion conductive polymer.

[0006]

However, in general,
Plasticizers such as tetraethylene glycol dimethyl ether, which can dissolve electrolyte salts and improve the conductivity of ion-conducting polymers, have a low boiling point, are highly vaporized and dissipated at high temperatures of 80 ° C or higher, and eventually have high ion conductivity. There is a problem that the conductivity of the molecule is lowered.

In order to solve the problems of the conventional ion conductive polymer, the present invention has high ion conductivity at room temperature and low temperature, and evaporates at high temperature of 80 ° C. or higher.
An object is to provide a stable ion conductive polymer with little dissipation.

[0008]

The ion conductive polymer composition of the present invention has an ethylene oxide polymer having a degree of polymerization n of 4≤n≤7 as a basic skeleton, and both ends thereof having 2 to 4 carbon atoms.
Of polyethylene glycol dialkyl ether (Chemical formula 1) end-capped with a lower alkyl, an allyl group or a cycloalkyl group, or an ethylene oxide polymer having a degree of polymerization n of 5 ≦ n ≦ 7 as a basic skeleton and methyl groups at both ends. It has a constitution containing at least one plasticizer consisting of polyethylene glycol dimethyl ether (Chemical Formula 2) end-capped with.

The relationship between the weight X of the polymer compound in the polymer composition and the weight Y of the polyethylene glycol dialkyl ether (Chemical formula 1) is 1 / 20≤Y / X≤20,
The relationship between the weight X of the polymer compound in the polymer composition and the weight W of polyethylene glycol dimethyl ether (Chemical Formula 2) is preferably 1/20 ≦ W / X ≦ 20.

[0010]

According to the constitution of the present invention, a plasticizer which dissolves and dissociates a large amount of an electrolyte salt, has a high boiling point, and has a low viscosity can be realized. And, as compared with conventionally known tetraethylene glycol dimethyl ether and the like, it is possible to obtain a resin having a lower viscosity and a higher boiling point, and as a result, use this as a plasticizer for an ion conductive polymer. Thus, it is possible to obtain a stable ion conductive polymer having high ion conductivity at room temperature and low temperature, and having little evaporation and dissipation at high temperature.

[0011]

EXAMPLES The present invention will be specifically described below with reference to examples.

First, the basic structure of the present invention will be described. The present invention is based on an ethylene oxide polymer having a degree of polymerization n of 4 ≦ n ≦ 7 as a basic skeleton, and polyethylene glycol dialkyl ether whose both ends are blocked with a lower alkyl having 2 to 4 carbon atoms, an allyl group or a cycloalkyl group. (Chemical formula 1)
Alternatively, an ethylene oxide polymer having a degree of polymerization n of 5 ≦ n ≦ 7 is used as a basic skeleton, and polyethylene glycol dimethyl ether (Chemical Formula 2) whose both ends are capped with methyl groups is used as a plasticizer for an ion conductive polymer.

[0013]

[Chemical 1]

[0014]

[Chemical 2]

That is, in the structural formula of polyethylene glycol dialkyl ether (Chemical formula 1), as the R ₁ and R ₂ groups of the terminal blocking group, methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group and phenyl group are used. Group, benzyl group, cycloalkyl group and the like.
Of these, a methyl group, an ethyl group, a propyl group and a butyl group are preferable. The polyethylene glycol dialkyl ether (Chemical formula 1) shown in claim 1 and the polyethylene glycol dimethyl ether (Chemical formula 2) shown in claim 2 may be used alone or in combination.

The ion conductive polymer usable in the plasticizer for the ion conductive polymer according to the present invention is not particularly limited, but preferably has polyether polyol as a basic skeleton, and the polyether portion has an ethylene oxide polymer and Propylene oxide polymer or a polymer compound of these copolymers cross-linked with diisocyanate, or the end of the polymer compound is isocyanate, cross-linked with diol, water and diamine, or the above-mentioned polymer compound The terminal is acrylated and crosslinked by irradiation with electron beam or ultraviolet ray.

Specific examples of ion conductive polymers using the plasticizer for ion conductive polymers of the present invention as constituent elements will be described below. (Example 1) Polymer compound 4 represented by the structural formula (Formula 3)
g, 1 g of ammonium borodisalicylate, and 4 g of the plasticizer for an ion-conductive polymer represented by Chemical formula 4 were dissolved in 8 ml of methyl ethyl ketone to obtain a uniform solution.

[0018]

[Chemical 3]

[0019]

[Chemical 4]

Then, the solution was cast on a glass petri dish to evaporate most of methyl ethyl ketone, and then 30
The polymer compound was cured by storing at a temperature of ° C for 1 hour to obtain a sheet-shaped polymer solid electrolyte. As a result of measuring the ionic conductivity by the AC impedance method, the ionic conductivities at 25 ° C. and −10 ° C. were 1.4 × 10 ⁻⁴ S / cm and 2.2 × 10 ⁻⁵ S / cm, respectively. Also, after leaving in air at 100 ° C for 24 hours, 25 ° C and -1
The ionic conductivity at 0 ℃ is 0.8 × 10 ^-4 S / cm,
It was 1.1 × 10 ^-5 S / cm. (Example 2) Polymer compound 4 represented by the structural formula (Formula 3)
g, 1 g of ammonium borodisalicylate, and 4 g of the plasticizer for an ion-conductive polymer represented by Chemical formula 5 were dissolved in 8 ml of methyl ethyl ketone to obtain a uniform solution.

[0021]

[Chemical 5]

Then, the solution was cast on a glass petri dish to evaporate most of methyl ethyl ketone and then 30
The polymer compound was cured by storing at a temperature of ° C for 1 hour to obtain a sheet-shaped polymer solid electrolyte. As a result of measuring the ionic conductivity by the AC impedance method, the ionic conductivities at 25 ° C. and −10 ° C. were 1.2 × 10 ⁻⁴ S / cm and 1.9 × 10 ⁻⁵ S / cm, respectively. Also, after leaving in air at 100 ° C for 24 hours, 25 ° C and -1
The ionic conductivity at 0 ℃ is 1.0 × 10 ^-4 S / cm, 1.
It was 6 × 10 ⁻⁵ S / cm. (Example 3) Polymer compound 4 represented by the structural formula (Formula 3)
g, 1 g of ammonium borodisalicylate, and 4 g of a plasticizer for an ion conductive polymer represented by Chemical formula 6 were dissolved in 8 ml of methyl ethyl ketone to obtain a uniform solution.

[0023]

[Chemical 6]

Then, the solution was cast on a glass petri dish to evaporate most of methyl ethyl ketone, and then 30
The polymer compound was cured by storing at a temperature of ° C for 1 hour to obtain a sheet-shaped polymer solid electrolyte. As a result of measuring the ionic conductivity by the AC impedance method, the ionic conductivities at 25 ° C. and −10 ° C. were 1.1 × 10 ⁻⁴ S / cm and 1.7 × 10 ⁻⁵ S / cm, respectively. Also, after leaving in air at 100 ° C for 24 hours, 25 ° C and -1
The ionic conductivity at 0 ° C is 1.1 × 10 ^-4 S / cm, 1.
It was 7 × 10 ⁻⁵ S / cm. (Example 4) Polymer compound 4 represented by the structural formula (Formula 3)
g, 1 g of ammonium borodisalicylate, and 4 g of the plasticizer for an ion conductive polymer represented by Chemical formula 7 were dissolved in 8 ml of methyl ethyl ketone to obtain a uniform solution.

[0025]

[Chemical 7]

Then, the solution was cast on a glass petri dish to evaporate most of methyl ethyl ketone and then 30
The polymer compound was cured by storing at a temperature of ° C for 1 hour to obtain a sheet-shaped polymer solid electrolyte. As a result of measuring the ionic conductivity by the AC impedance method, the ionic conductivities at 25 ° C. and −10 ° C. were 1.2 × 10 ⁻⁴ S / cm and 1.8 × 10 ⁻⁵ S / cm, respectively. Also, after leaving in air at 100 ° C for 24 hours, 25 ° C and -1
The ionic conductivity at 0 ℃ is 1.0 × 10 ^-4 S / cm, 1.
It was 6 × 10 ⁻⁵ S / cm. (Example 5) Polymer compound 4 represented by the structural formula (Formula 3)
g, 1 g of ammonium borodisalicylate, and 4 g of the plasticizer for an ion conductive polymer represented by Chemical formula 8 were dissolved in 8 ml of methyl ethyl ketone to obtain a uniform solution.

[0027]

[Chemical 8]

Then, the solution was cast on a glass petri dish to evaporate most of methyl ethyl ketone, and then 30
The polymer compound was cured by storing at a temperature of ° C for 1 hour to obtain a sheet-shaped polymer solid electrolyte. As a result of measuring the ionic conductivity by the AC impedance method, the ionic conductivities at 25 ° C. and −10 ° C. were 0.8 × 10 ⁻⁴ S / cm and 1.0 × 10 ⁻⁵ S / cm, respectively. Also, after leaving in air at 100 ° C for 24 hours, 25 ° C and -1
The ionic conductivity at 0 ℃ is 0.8 × 10 ^-4 S / cm, 1.
It was 0 × 10 ⁻⁵ S / cm. (Comparative Example 1) Polymer compound 4 represented by the structural formula (Formula 3)
g, ammonium borodisalicylate 1 g, and tetraethylene glycol dimethyl ether 4 g were dissolved in methyl ethyl ketone 8 ml to obtain a uniform solution. Then, the solution was cast on a glass petri dish to evaporate most of methyl ethyl ketone, and then stored at a temperature of 30 ° C. for 1 hour to cure the polymer compound to obtain a sheet-like polymer solid electrolyte. It was As a result of measuring the ionic conductivity by the AC impedance method, the ionic conductivities at 25 ° C. and −10 ° C. are 1.5 × 10 ⁻⁴ S / c, respectively.
m, 1.8 × 10 ^-6 S / cm. Also, at 100 ° C in air 24
The ionic conductivities at 25 ° C. and −10 ° C. after standing for hours were 1.2 × 10 ⁻⁵ S / cm and 4.0 × 10 ⁻⁷ S / cm, respectively.

In this embodiment, structural formulas (Formula 4) to (Formula 8)
Although the one represented in (1) is used, the same effect can be obtained with the other structures described in claims 1 and 2.

Further, in this embodiment, the weight X of the polymer compound is
And polyethylene glycol dialkyl ether weight Y
Alternatively, the ratio between the weight X of the polymer compound and the weight W of polyethylene glycol dimethyl ether is Y / X =
Although 1 and W / X = 1, similar effects can be obtained with other weight ratios described in claims 2 and 4.

[0031]

As is apparent from the above description,
The ion-conductive polymer according to the present invention has the advantages of high ionic conductivity and being extremely stable even at high temperatures, and contributes to high performance and long life of electrochemical devices such as electrolytic capacitors. is there.

Claims (4)

[Claims] 1. An ethylene oxide polymer having a degree of polymerization n of 4 ≦ n ≦ 7 as a basic skeleton, and both ends thereof having 2 to 4 carbon atoms.
2. An ion conductive polymer composition, comprising at least one plasticizer containing a polyethylene glycol dialkyl ether (Chemical Formula 1) end-capped with a lower alkyl, an allyl group or a cycloalkyl group. [Chemical 1] 2. The weight X of the polymer compound in the polymer composition
And the weight Y of the polyethylene glycol dialkyl ether (Chemical Formula 1) is 1/20 ≦ Y / X ≦ 20. 3. At least one plasticizer containing an ethylene oxide polymer having a degree of polymerization n of 5 ≦ n ≦ 7 as a basic skeleton and polyethylene glycol dimethyl ether (Chemical Formula 2) having both ends blocked with methyl groups is added. An ion-conducting polymer composition characterized by the above. [Chemical 2] 4. The weight X of the polymer compound in the polymer composition.
4. The ion conductive polymer composition according to claim 3, wherein the relation between the weight and the weight W of the polyethylene glycol dimethyl ether (Chemical Formula 2) is 1/20 ≦ W / X ≦ 20.