JP2001273815A - Conductive material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a conductive material in which blooming or bleeding is hard to seep out and electrical conduction durability is superior. SOLUTION: This conductive material contains quaternary ammonium salt shown by the following general formula as an ion conductive agent. [In the formula, R1-R4 show independently an alkyl group which may be the same or different from each other, and at least one has a terminal OH group. Xn- shows a negative ion of n valence and n shows an integers 1-6].

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a conductive material suitably used as a constituent material of a conductive member such as a developing roll, a charging roll and a transfer roll in an electrophotographic apparatus such as a copying machine, a printer and a facsimile. It is.

[0002]

2. Description of the Related Art Conventionally, as a constituent material of a conductive member such as a developing roll, a charging roll and a transfer roll, a conductive material obtained by adding an electronic conductive agent such as carbon black to a polar polymer such as polyurethane has been used. Have been. In a conductive member using such a conductive material, the electric resistance is adjusted to a predetermined range (medium resistance region) by adjusting the amount of the electronic conductive agent. There are difficulties such as variations in electrical resistance and large voltage dependence. Therefore, instead of the conventional electronic conductive agent, an ionic conductive agent having advantages such as variation in electric resistance and small voltage dependency has been used.

[0003]

However, when the above-mentioned conventional ionic conductive agent is used, the current-carrying durability is inferior, and bloom, bleed, etc. of the ionic conductive agent occur.
There is a problem that the ionic conductive agent easily exudes. Therefore, variations in electrical resistance, which is an advantage of the ion conductive agent,
There is a need for a conductive material that has improved short-circuit durability and bleeding of the ionic conductive agent, which are disadvantages, while taking advantage of small voltage dependency and the like.

The present invention has been made in view of such circumstances, and an object of the present invention is to provide a conductive material which is excellent in current-carrying durability and hardly exudes bloom, bleed, and the like.

[0005]

In order to achieve the above-mentioned object, the conductive material of the present invention contains a quaternary ammonium salt represented by the following general formula (1) as an ionic conductive agent. Take the configuration.

[0006]

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That is, the present inventors have conducted intensive studies on quaternary ammonium salts, which are ionic conductive agents, in order to obtain a conductive material which is excellent in current-carrying durability and hardly seeps out of the ionic conductive agent. . Focusing on the four substituents bonded to N on the positive ion side of the quaternary ammonium salt, and recalled that good results could be obtained when all four substituents were alkyl groups, It has been found that not all alkyl groups give good results. Therefore, as a result of further research and development on a preferable alkyl group, if at least one of the four alkyl groups bonded to N has a terminal OH group, the compatibility with the polar polymer is improved, and stains such as bloom and bleed are caused. It has been found that the OH group is less likely to occur, and even if polarization occurs with the passage of time, it can be suppressed by the terminal OH group.

By setting the blending amount of the specific quaternary ammonium salt with respect to the polar polymer in a specific range, both the effect of improving the current-carrying durability and the effect of preventing the quaternary ammonium salt from exuding can be obtained. The balance is the best.

[0009]

Next, an embodiment of the present invention will be described.

The conductive material of the present invention can be obtained by using a quaternary ammonium salt represented by the following general formula (1) as an ionic conductive agent.

[0011]

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The alkyl group represented by R ^{1 to} R ⁴ is
It may be linear, branched, or cyclic, and
Although the number of carbon atoms of the alkyl group is not particularly limited, it is preferably 1 to 22, and particularly preferably 1 to 12. As the alkyl group, specifically, methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group, nonyl group, decyl group, undecyl group,
A dodecyl group is preferred.

The most important feature of the present invention is that a quaternary ammonium salt having at least one terminal OH group among the alkyl groups represented by R ^{1 to} R ⁴ is used.
Then, all of the above R ^{1 to} R ⁴ may have a terminal OH group, but it is preferable that any one of R ^{1 to} R ⁴ does not have a terminal OH group.

Examples of the alkyl group having a terminal OH group include a hydroxymethyl group, a hydroxyethyl group, a hydroxypropyl group, a hydroxybutyl group, a hydroxypentyl group, a hydroxyhexyl group, a hydroxyheptyl group, and a hydroxyoctyl group. , Hydroxynonyl group, hydroxydecyl group, hydroxyundecyl group,
A hydroxydodecyl group and the like are preferred.

In the above general formula (1), the n-valent anion represented by X ^n- is not particularly limited. For example, halogen ions such as F ⁻ , Cl ⁻ , Br ⁻ and I ⁻ , ClO ₄ ⁻ , BF ₄ ⁻ , SO ₄ ²⁻ , HSO ₄ ⁻ , C
H ₃ SO ₄ ⁻ , C ₂ H ₅ SO ₄ ⁻ , CH ₃ SO ₃ ⁻ , C
^{_{2 H 5 SO 3 -, COOH}} - and the like. Among these, in that it can have lower resistance, Br ^-, I ^-,
ClO ₄ ⁻ , HSO ₄ ⁻ , and C ₂ H ₅ SO ₄ ⁻ are preferred.

In the general formula (1), among the integers 1 to 6 represented by n, an integer of 1 to 4 is preferable, and an integer of 1 or 2 is particularly preferable.

The polar polymer in the conductive material of the present invention is not particularly limited as long as it has polarity.
For example, epichlorohydrin rubber (CO), epichlorohydrin-ethylene oxide copolymer rubber (ECO),
Acrylonitrile butadiene rubber (NBR), polyurethane, chloroprene rubber, chlorosulfonated polyethylene rubber, ethylene oxide-propylene oxide copolymer, ethylene oxide-propylene oxide-
Allyl glycidyl ether copolymer, epichlorohydrin-ethylene oxide-allyl glycidyl ether copolymer rubber and the like can be mentioned. These may be used alone or in combination of two or more. Among these, CO, ECO, NBR, and the like, in which the electric resistance of the polar polymer itself is low and the compatibility with the specific quaternary ammonium salt is excellent.
Polyurethane is preferably used.

The amount of the specific quaternary ammonium salt with respect to the polar polymer is 0.01 to 20 parts by weight (hereinafter abbreviated as "part") with respect to 100 parts by weight of the polar polymer. It is preferably set in the range of parts, particularly preferably 0.1 to 5 parts. That is, when the amount of the specific quaternary ammonium salt is less than 0.01 part, the volume resistivity tends to increase, and when it exceeds 20 parts, the volume resistivity increases,
This is because the quaternary ammonium salt tends to exude.

The conductive material of the present invention includes, in addition to the specific quaternary ammonium salt and the polar polymer,
Crosslinking agents, crosslinking accelerators, processing aids, anti-aging agents, softeners,
A reinforcing agent or the like may be added as needed.

In the conductive material of the present invention, a conductive filler may be used in combination with the specific quaternary ammonium salt. Examples of the conductive filler include metal powders such as aluminum powder and stainless steel powder;
_{c-ZnO, c-TiO 2} , c-Fe 3 O 4, c-Sn
Conductive metal oxides such as O ₂ ; conductive powders such as graphite and carbon black; and ionic conductive agents such as phosphates, sulfonates, aliphatic polyhydric alcohols, and aliphatic alcohol sulfates. These may be used alone or in combination of two or more. Note that the above “c”
"-" Means having conductivity.

The conductive material of the present invention is, for example,
It can be manufactured as follows. That is, first, the above-mentioned specific quaternary ammonium salt is added as an ionic conductive agent to a polar polymer such as the above-mentioned epichlorohydrin-ethylene oxide copolymer rubber (ECO), and other additives are added if necessary. Added. Then
The desired conductive material can be obtained by kneading these using a kneader such as a kneader or a Banbury mixer. The conductive material is used after being processed into a sheet shape by, for example, press molding.

The use of the thus obtained conductive material of the present invention is not particularly limited, but the conductive material such as a developing roll, a charging roll and a transfer roll in an electrophotographic apparatus such as a copying machine, a printer, a facsimile, etc. It is suitably used as a constituent material of a member.

Next, examples will be described together with comparative examples.

[0024]

Example 1 ECO (equimolar copolymer of epichlorohydrin and ethylene oxide) 100 as a polar polymer
, 5 parts of lead acid as an acid acceptor, 1.5 parts of a thiourea-based crosslinking accelerator (Suncellar 22C, manufactured by Sanshin Chemical Co., Ltd.), and a fourth ion represented by the following formula (2) as an ionic conductive agent. After kneading 1 part of a quaternary ammonium salt with a Banbury mixer, the mixture was press-molded to produce a 0.7 mm-thick conductive sheet.

[0025]

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[0026]

Example 2 The amount of the quaternary ammonium salt represented by the above formula (2) was changed to 5 parts. Otherwise, Example 1
In the same manner as in the above, a conductive sheet was produced.

[0027]

Example 3 The amount of the quaternary ammonium salt represented by the above formula (2) was changed to 0.1 part. Otherwise, a conductive sheet was produced in the same manner as in Example 1.

[0028]

Example 4 The amount of the quaternary ammonium salt represented by the above formula (2) was changed to 0.01 part. Otherwise, a conductive sheet was produced in the same manner as in Example 1.

[0029]

Example 5 The amount of the quaternary ammonium salt represented by the above formula (2) was changed to 20 parts. Otherwise, a conductive sheet was produced in the same manner as in Example 1.

[0030]

Example 6 A quaternary ammonium salt represented by the following formula (3) was used in place of the quaternary ammonium salt represented by the above formula (2). Otherwise, a conductive sheet was produced in the same manner as in Example 1.

[0031]

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[0032]

Example 7 ECO (equimolar copolymer of epichlorohydrin and ethylene oxide) 100 as a polar polymer
Parts, 5 parts of lead acid as an acid acceptor, 1.5 parts of a thiourea-based cross-linking accelerator (Suncellar 22C, manufactured by Sanshin Chemical Co., Ltd.), and a fourth agent represented by the following formula (4) as an ionic conductive agent. After kneading 1 part of a quaternary ammonium salt with a Banbury mixer, the mixture was press-molded to produce a 0.7 mm-thick conductive sheet.

[0033]

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[0034]

Example 8 The amount of the quaternary ammonium salt represented by the above formula (4) was changed to 5 parts. Otherwise, Example 7
In the same manner as in the above, a conductive sheet was produced.

[0035]

Example 9 The amount of the quaternary ammonium salt represented by the above formula (4) was changed to 0.1 part. Otherwise, in the same manner as in Example 7, a conductive sheet was produced.

[0036]

Example 10 The amount of the quaternary ammonium salt represented by the above formula (4) was changed to 0.01 part. Other than that,
A conductive sheet was produced in the same manner as in Example 7.

[0037]

Example 11 The amount of the quaternary ammonium salt represented by the above formula (4) was changed to 20 parts. Otherwise, in the same manner as in Example 7, a conductive sheet was produced.

[0038]

Comparative Example 1 A quaternary ammonium salt represented by the following formula (5) was used in place of the quaternary ammonium salt represented by the above formula (2). Otherwise, a conductive sheet was produced in the same manner as in Example 1.

[0039]

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[0040]

Comparative Example 2 The amount of the quaternary ammonium salt represented by the above formula (5) was changed to 5 parts. Otherwise, Comparative Example 1
In the same manner as in the above, a conductive sheet was produced.

[0041]

Comparative Example 3 A quaternary ammonium salt represented by the following formula (6) was used in place of the quaternary ammonium salt represented by the above formula (4). Otherwise, in the same manner as in Example 7, a conductive sheet was produced.

[0042]

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[0043]

Comparative Example 4 The amount of the quaternary ammonium salt represented by the above formula (6) was changed to 5 parts. Otherwise, Comparative Example 3
In the same manner as in the above, a conductive sheet was produced.

The electroconductive durability, volume resistivity and bloom were evaluated according to the following criteria using the thus obtained conductive sheets of Example and Comparative Examples.
The results are shown in Tables 1 and 2 below.

[Electrification Durability and Volume Resistivity] The conductive sheet was cut into a predetermined size (30 mm × 30 mm), and a silver paste was applied thereon to form a 1 cm square electrode. Then, under a low-temperature and low-humidity environment of 15 ° C. × 10% RH, a predetermined voltage (1000 V) is applied, and the volume resistivity (Rv1) after 5 seconds is measured using a model 237 (KEITH).
LEY). Similarly, the volume resistivity (Rv2) after 600 seconds was measured. And log
The current-carrying durability was evaluated based on the value of (Rv2 / Rv1). The smaller the value of log (Rv2 / Rv1), the smaller the increase in volume resistivity, that is, the better the durability to energization.

[Bloom] The above conductive sheet was left in a folded state in an environment of 40 ° C. × 80% RH for one month, and then the seeping out of the quaternary ammonium salt was visually observed. The evaluation criteria were set as follows. ：: There is no exudation of the quaternary ammonium salt △: There is some exudation of the quaternary ammonium salt ×: There is much exudation of the quaternary ammonium salt

[0047]

[Table 1]

[0048]

[Table 2]

From the results shown in Tables 1 and 2, it can be seen that all of the products of Examples are excellent in the durability against current application and hardly cause the quaternary ammonium salt to exude. On the other hand, it can be seen that the comparative example product is inferior in at least one of the characteristics of the conduction durability and the bloom. From this fact, when at least one of the alkyl groups bonded to N on the positive ion side of the quaternary ammonium salt has a terminal OH group, the current durability is excellent and the quaternary ammonium salt exudes. It can be seen that the occurrence of is difficult.

[0050]

As described above, the conductive material of the present invention
It contains a specific quaternary ammonium salt as an ion conductive agent. And since the said specific quaternary ammonium salt has the terminal OH group at least one of the alkyl groups couple | bonded with N of a positive ion side, compatibility with a polar polymer improves and bloom, bleeding Exudation is less likely to occur, and even if polarization occurs with the passage of time, it can be suppressed by the terminal OH group, so that the current-carrying durability is excellent.

By setting the blending amount of the specific quaternary ammonium salt with respect to the above-mentioned polar polymer in a specific range, both the effect of improving the current-carrying durability and the effect of preventing the quaternary ammonium salt from exuding can be obtained. The balance is the best.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification code FI Theme coat ゛ (Reference) G03G 15/08 501 G03G 15/08 501D 5G301 15/16 103 15/16 103 H01B 1/12 H01B 1/12 Z (72) Inventor Jiro Iwashiro 3-1, Higashi 3-chome, Komaki City, Aichi Prefecture F-term (reference) 2H003 BB11 CC05 2H032 AA05 BA23 2H077 AD06 DB14 FA13 FA23 FA27 3J103 AA02 AA51 FA07 FA09 FA12 FA14 GA02 GA57 GA58 GA60 GA74 HA04 HA20 HA48 HA53 HA60 4J002 AC071 AC091 BB271 CH021 CH041 CK021 EN136 FD010 GQ02 5G301 DA28 DA42 DA59 DD08 DD10

Claims (4)

[Claims] 1. A conductive material comprising a quaternary ammonium salt represented by the following general formula (1) as an ionic conductive agent. Embedded image 2. The conductive material according to claim 1, wherein a quaternary ammonium salt represented by the general formula (1) is added to a polar polymer. 3. The conductive material according to claim 2, wherein the polar polymer is at least one selected from the group consisting of epichlorohydrin rubber, epichlorohydrin-ethylene oxide copolymer rubber, acrylonitrile butadiene rubber, and polyurethane. material. 4. The compounding amount of the quaternary ammonium salt is as follows:
0.01 to 2 parts by weight per 100 parts by weight of the polar polymer
4. The conductive material according to claim 2, wherein the conductive material is set in a range of 0 parts by weight.