JPH11293128A - Electroconductive polymer member and image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an electroconductive polymer member with suppressed resistance fluctuation and excellent durability, suitable as, e.g. an electrophotographic member, by using an electroconductive polymeric material prepared by incorporating a specific quaternary ammonium salt in a polymer compound containing a polar structural unit. SOLUTION: This polymer member is obtained by using an electroconductive polymer material which is prepared by incorporating a polymer compound containing a polar structural unit such as polyurethane with a quaternary ammonium salt having one or more amido linkage such as lauroyl iminopropyl dimethyl ethyl ammonium ethyl sulfate; wherein the acid group in the quaternary ammonium salt is pref. an organic acid group such as carboxylate or alkyl sulfate. It is preferable that the other objective image forming device is manufactured by mounting the above electroconductive polymeric member.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a conductive polymer member and an image forming apparatus. More specifically, the present invention provides a conductive polymer member in which the resistance in a high-temperature and high-humidity environment and the resistance in a low-temperature and low-humidity environment are suppressed, and is suitable as an electrophotographic member or the like. The present invention relates to a mounted image forming apparatus.

[0002]

2. Description of the Related Art In recent years, with the progress of electrophotographic technology, image forming apparatuses such as dry electrophotographic apparatuses have been used for charging, developing,
Attention has been paid to polymer members as members used for transfer, toner supply, and the like, and they are used in the form of elastic rollers such as a charging roller, a developing roller, a transfer roller, and a toner supply roller. In processes such as charging and transfer using an elastic roller, this polymer member has the advantage that compared to conventional corotron chargers, the required image forming body charging potential and toner transfer amount can be obtained with a lower power supply voltage. is there. As the polymer member used for these purposes, a polymer elastomer or foam such as rubber or polyurethane is usually used. ⁴ to 10 ¹⁰
It is often required to have a predetermined resistance value in a medium resistance region of Ω. However, by mixing metal or metal oxide powder or carbon black, it is difficult to manufacture a polymer member having a constant resistance value in a medium resistance region required as a conductive member for electrophotography and the like. However, even if it can be manufactured, there are problems such as a large variation in the position of the electric resistance and a large voltage dependence of the electric resistance. On the other hand, by using a polar polymer material mixed with an ion conductive substance such as sodium perchlorate, a polymer that has substantially no resistance variation and voltage dependence of resistance in the medium resistance region It is known that a member can be manufactured. However, such a polymer member has resistance in a high temperature and high humidity environment such as 32.5 ° C. and 85%, and low temperature and low humidity such as 15 ° C. and 10%. In addition to the large fluctuation of the resistance in the environment, there has been a problem that the ionic conductive substance is hyperpolarized due to long-time continuous energization, and the electric resistance increases.

[0003]

SUMMARY OF THE INVENTION The present invention overcomes the above-mentioned drawbacks of the conventional conductive polymer member, and suppresses fluctuations in resistance in a high-temperature, high-humidity environment and in low-temperature, low-humidity environment. At the same time, the resistance rise is suppressed even in continuous use,
It is an object of the present invention to provide a conductive polymer member suitable as a member for electrophotography and an image forming apparatus equipped with the conductive polymer member.

[0004]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies to achieve the above object, and as a result, have found that a polar polymer compound containing a quaternary ammonium salt having an amide bond can be used. In the case of a member using a polymer material, the resistance in a high-temperature and high-humidity environment and the resistance in a low-temperature and low-humidity environment are suppressed, and the resistance increase is suppressed even in continuous use.
It has been found that it is suitable as a member for electrophotography and the like. The present invention has been completed based on such findings.

That is, the present invention uses (1) a conductive polymer material in which a polymer compound containing a polar structural unit contains a quaternary ammonium salt having at least one amide bond. A conductive polymer member, (2) the conductive polymer member according to the above (1), which is used as an electrophotographic member, and (3) the above (1),
(2) An image forming apparatus provided with the conductive polymer member.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION The conductive polymer material used for the conductive polymer member of the present invention is a polymer compound having a polar structural unit (hereinafter, sometimes referred to as a polar polymer compound). , A quaternary ammonium salt having at least one amide bond to impart electrical conductivity. The polar polymer compound may include a structural unit having polarity, and may have any appropriate flexibility, and is not particularly limited, and may be selected from various polar polymer compounds according to various situations. It can be selected as appropriate. Examples of such a polar polymer compound include polyurethane, NBR, urethane rubber (kneaded type), epichlorohydrin rubber, acrylic rubber,
Polar rubbers such as chloroprene can be mentioned,
Of these, polyurethane is particularly preferred. Examples of the polyurethane include those containing hydrophilic polyols such as polyether polyols, polyester polyols, polytetramethylene ether glycol, or polyols obtained by addition polymerization of polyhydric alcohols such as glycerin with ethylene oxide or propylene oxide. preferable.

In the present invention, one kind of the polar polymer compound may be used, or two or more kinds thereof may be used in combination. In addition, as long as the effects of the present invention are not impaired, if desired, the compound may be used in combination with a nonpolar polymer compound such as a hydrophobic rubber such as polyisoprene, polybutadiene, and hydrogenated polybutadiene. By including such a polar polymer compound with a quaternary ammonium salt having at least one amide bond, the resistance is adjusted to a medium resistance region of 10 ⁴ to 10 ¹⁰ Ω and 32.5.
Resistance in high temperature and high humidity environment such as 85%, 15 ℃, 1
It is possible to obtain a conductive polymer material which can suppress a change in resistance in a low-temperature and low-humidity environment such as 0%, and can provide a conductive polymer member capable of suppressing a rise in resistance even for a long-time continuous energization. In the present invention, it is also preferable that the conductive polymer material be a foam. The foaming method for foaming is not particularly limited, and a method using water or a foaming agent, a method of mixing bubbles by mechanical stirring, and the like are preferably used. In addition, a filler-based conductive agent such as carbon black, metal powder, or metal oxide powder can be appropriately added to the conductive polymer material of the present invention as long as the effects of the present invention are not impaired.

In the present invention, when polyurethane is used as the polar high molecular compound, the method for producing the conductive high molecular material is not particularly limited. For example, the above-mentioned hydrophilic polyol, ethylene glycol, propanediol, butanediol, etc. And a crosslinking agent such as tolylene diisocyanate (TDI), diphenylmethane diisocyanate (MDI), crude diphenylmethane diisocyanate (crude MDI), or isophorone diisocyanate. A method of mixing with a reinforcing colorant such as an ammonium salt or carbon black, a crosslinking reaction catalyst, and the like, followed by heating and curing is preferably used. Further, a method in which the above polyols are converted into isocyanates in advance and cured using a chain extender such as ethylene glycol, 1,4-butanediol, or trimethylolpropane is also preferably used.

On the other hand, when rubbers are used as the polar polymer compound, the method for producing the conductive polymer material is not particularly limited. For example, NBR, urethane rubber (kneading type), epichlorohydrin rubber, acrylic To polar rubbers such as rubber and chloroprene rubber, quaternary ammonium salts used for imparting conductivity, crosslinking agents such as sulfur and dicumyl peroxide, vulcanization aids such as zinc white, benzothiazole derivatives, etc. A known method of adding a compounding agent such as an antioxidant such as a vulcanization accelerator and various amines, kneading with a Banbury mixer or a kneader, and then crosslinking with heating or an electron beam can be used. A foam can be obtained by adding a blowing agent such as benzenesulfonyl hydrazide). As the quaternary ammonium salt having at least one amide bond used in the present invention, there are various ones, which may be appropriately selected according to the situation. For example, general formula (I)

[0010]

Embedded image

(Where R¹~ R^FourAre each 1 carbon
Alkyl group having 1 to 30 carbon atoms, aminoalkyl having 1 to 30 carbon atoms
Group, an aryl group having 6 to 30 carbon atoms, an aryl group having 6 to 30 carbon atoms
Minoaryl group, aralkyl group having 7 to 30 carbon atoms, carbon
An aminoaralkyl group having 7 to 30 carbon atoms and an aminoaralkyl group having 7 to 30 carbon atoms;
Alkylaryl group or aminoalkyl having 7 to 30 carbon atoms
Aryl groups, which are the same or different
A may be an alkylene group having 1 to 30 carbon atoms,
An aminoalkylene group having 1 to 30 carbon atoms, an alkylene group having 6 to 30 carbon atoms,
Arylene group, aminoarylene group having 6 to 30 carbon atoms, charcoal
An aralkylene group having a prime number of 7 to 30, an amine having a carbon number of 7 to 30;
Noaralkylene group, alkyl arylene having 7 to 30 carbon atoms
Or an aminoalkylarylene group having 7 to 30 carbon atoms
And X ^n-Represents an n-valent acid radical. Note that n is 1 to 6.
It is an integer. )).
You. Where X^n-Especially the type of acid radical shown by
Although there is no limitation, it suppresses hyperpolarization when organic acid radicals are continuously energized
It is preferable because it can be performed. As this organic acid radical, for example,
Such as methyl sulfate, ethyl sulfate, and propyl sulfate;
Alkyl sulfates, acetates, malonates, malates,
Succinate, oxalate, maleate, fumarate,
Phthalates, isophthalates, terephthalates, trimes
Lit acid group, trimesic acid group, tricarboxylate group, etc.
The carboxylic acid group of the above is preferably mentioned.

The conductive polymer member of the present invention uses the conductive polymer material thus obtained,
When the conductive polymer member is a conductive roller, it is usually manufactured by coating a core metal made of plated iron or stainless steel with the above conductive polymer material. . Depending on the application, this conductive roller
The outside may be coated with a conductive, semiconductive, or insulating paint. This is 10 ⁴ to 10 ¹⁰ Ω
Shows a stable resistance value in the middle resistance region. The use of the conductive polymer member of the present invention is not particularly limited, but is preferably used as an electrophotographic member, and is suitable as, for example, a transfer member, a developing member, a charging member, a toner supplying member, and the like. Used for The present invention also provides an image forming apparatus equipped with the conductive polymer member. For example, when the image forming apparatus is incorporated in an electrophotographic image forming apparatus such as a copying machine, a transfer member, a developing member,
It is applied to a charging member, a toner supply member, and the like. Next, the conductive polymer member of the present invention is used as a transfer member.
An example in which the image forming apparatus is mounted on an image forming apparatus will be described.

FIG. 1 is an explanatory view showing an example of an electrophotographic image forming apparatus using a conductive polymer member (transfer member) of the present invention, which is provided with a metal core (not shown). The transfer member (transfer roller) 1 of the present invention is brought into contact with an image forming body (photoreceptor) 2 via a recording medium (transfer material) 4 such as paper, and the transfer member 1 and the image forming body 2 During this time, a voltage is applied by the power supply 3 to generate an electric field between the image forming body and the transfer member, thereby transferring the toner on the image forming body 2 to the recording medium 4.

[0014]

Next, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples. Example 1 Propylene oxide and ethylene oxide were randomly added to glycerin, and the content of oxyethylene units was 16
Weight%, the number of functional groups is substantially 3, weight average molecular weight 5000
Was prepared. 100 parts by weight of this polyether polyol was previously heated to 40 ° C.
Diphenylmethane diisocyanate 30 heated to 0 ° C
Parts by weight, stirred and placed in a closed container.
After reacting for an hour, the isocyanate group content was 5.6.
7% by weight of prepolymer was obtained. 60 parts by weight of the prepolymer thus obtained, weight average molecular weight of 100
0, the terminal hydroxyl group is substantially primary (primary conversion 9
9%) polytetramethylene ether glycol 16.2 parts by weight, polytetramethylene ether glycol 2 having a weight average molecular weight of 3,000 and having substantially primary terminal hydroxyl groups
3.8 parts by weight, 4 parts by weight of a reactive silicone foam stabilizer, 1 part by weight of lauroyl iminopropyldimethylethylammonium ethyl sulfate and 0.003 part by weight of dibutyltin dilaurate are mixed while foaming by mechanical stirring, and this mixture is mixed. Was used to produce a urethane foam roller having a diameter of 16.5 mm and a length of 215 mm, which was disposed around a metal shaft having a diameter of 6 mm.

The above-mentioned roller was placed on an aluminum plate having a thickness of 5 mm, and the electric resistance between the core metal and the copper plate was measured while pressing both ends of the roller with a force of 500 g each. The temperature and humidity at the time of measurement were 20 ° C. and 50%, respectively.
The electric resistance is 1.1 × 10 ⁸ when the applied voltage is 1000 V.
Ω. The temperature and humidity at the time of measurement were 35
At 85 ° C and 85%, the electric resistance is 1.7 at an applied voltage of 1000 V.
× 10 ⁷ Ω, 15 ° C, 10%, applied voltage 1000V
Was 4.5 × 10 ⁸ Ω. The electric resistance at 15 ° C. and 10% is divided by the electric resistance at 32.5 ° C. and 85%.
The environmental index expressed by its common logarithm was 1.42. The roller was incorporated as a transfer roller in the image forming apparatus shown in FIG. When grayscale, solid black and white solid images were printed in an environment where the temperature and humidity were 15 ° C. and 10%, respectively, good images were obtained. Further, in an environment where the temperature and humidity were 32.5 ° C. and 85%, respectively. When a grayscale, black solid, or white solid image was printed, a good image was obtained. Next, the photoreceptor of the image forming apparatus was changed to an aluminum tube, and in an environment of a temperature of 20 ° C and a humidity of 50%,
After continuously rotating for 150 hours while applying a voltage of 000 V, the resistance was measured by the same method as described above. As a result, the electric resistance was 1.1 × 10 at 20 ° C. and 50%.
^{8 Ω,} 32.5 ℃, with ^{85% 1.7 × 10 7 Ω,} 15 ℃, 1
It was 4.5 × 10 ⁸ Ω at 0%. This transfer roller is incorporated in the image forming apparatus in the same manner as described above, and the temperature is set to 15 ° C. and the humidity is set to 1
When a gray scale, solid black, and solid white image was printed in an environment of 0%, a good image was obtained.

Comparative Example 1 In Example 1, 0.4 parts by weight of an ethyl sulphate-modified aliphatic dimethylethylammonium (containing no amide bond) was used in place of 1 part by weight of lauroyl iminopropyldimethylethylammonium ethyl sulfate. Except for
It carried out similarly to Example 1. As a result, the initial resistance is 6.3 × 10 ⁷ Ω at 20 ° C. and 50%, 32.5 ° C., 85
% At 5.0 × 10 ⁶ Ω, 15 ° C, 10% at 3.5 × 10 ⁸ Ω
Met. The electric resistance at 15 ° C. and 10% is 32.5
The environmental index was 1.84 divided by the electrical resistance at 85 ° C. and expressed as a common logarithm. Next, the photosensitive member of the image forming body was changed to an aluminum tube, and continuously rotated for 150 hours while applying a voltage of 1000 V in an environment of a temperature of 20 ° C. and a humidity of 50%. The resistance was measured by the method described above. As a result, the electric resistance is 2
9.0 × 10 ⁷ Ω at 0 ° C., 50%, 5.25 ° C. at 85%, 32.5 ° C.
It was 9.3 × 10 ⁸ Ω at 0 × 10 ⁶ Ω, 15 ° C. and 10%.

[0017]

According to the conductive polymer member of the present invention, the resistance in a high-temperature and high-humidity environment and the resistance in a low-temperature and low-humidity environment are suppressed, and the resistance increase is suppressed even in continuous use.
It is suitable as an electrophotographic member such as a transfer member, a developing member, a charging member, and a toner supplying member.

[Brief description of the drawings]

FIG. 1 is an explanatory view showing an example of an electrophotographic image forming apparatus using a conductive polymer member of the present invention.

[Explanation of symbols]

 1: transfer member (transfer roller) 2: image forming body (photoreceptor) 3: power supply 4: recording medium (transfer material)

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification code FI G03G 15/08 501 G03G 15/08 501A 501D 15/16 103 15/16 103

Claims (10)

[Claims] 1. A conductive polymer material comprising a polymer compound containing a polar structural unit and a quaternary ammonium salt having at least one amide bond. Polymer members. 2. The conductive polymer member according to claim 1, wherein the polymer compound containing a polar structural unit is polyurethane. 3. The conductive polymer member according to claim 1, wherein the acid radical of the quaternary ammonium salt having at least one amide bond is an organic acid. 4. The conductive polymer member according to claim 3, wherein the organic acid is a carboxylic acid or an alkyl sulfuric acid. 5. The conductive polymer member according to claim 1, which is used as an electrophotographic member. 6. The conductive polymer member according to claim 5, wherein the electrophotographic member is a transfer member. 7. The conductive polymer member according to claim 5, wherein the electrophotographic member is a developing member. 8. The conductive polymer member according to claim 5, wherein the electrophotographic member is a charging member. 9. The conductive polymer member according to claim 5, wherein the electrophotographic member is a toner supply member. 10. An image forming apparatus equipped with the conductive polymer member according to claim 1.