JP2003015399A - Toner supply roll - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a toner supply roll having low electric resistance in an early stage and excellent energization durability. SOLUTION: The toner supply roll has a shaft and at least one layer formed on the peripheral surface of the shaft and the innermost layer is formed using an electrically conductive material containing a quaternary ammonium salt of formula (1) as an ionic conductor. In the formula (1), R<1> -R<4> are each alkyl, at least one is different from each other, at least one is a 4-12C alkyl; X<n-> is an n-valent anion; and (n) is an integer of 1-6.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a toner supply roll used in an electrophotographic apparatus such as a copying machine, a printer and a facsimile.

[0002]

2. Description of the Related Art Conventionally, in an image forming apparatus such as a copying machine, a printer or a facsimile, an electrostatic latent image is formed on an image bearing member composed of an electrophotographic photosensitive member, an electrostatic recording dielectric member, etc. A latent image is developed by a developing device to be visualized as a toner image. Such a developing device has a built-in toner supply roll for supplying a predetermined toner (developer) contained in the hopper to the image carrier side. As the toner supply roll, one having a structure in which a soft urethane foam layer is formed on the outer peripheral surface of the shaft is used. In order to stabilize the electric resistance, it has been proposed that the soft urethane foam layer contains a quaternary ammonium salt as a conductive agent (JP-A-10-169641).

[0003]

However, since the roll described in Japanese Patent Laid-Open No. 10-169641 has a high initial electric resistance, a desired current value does not flow at a constant voltage and an image defect occurs. However, there is a drawback that it is inferior in current durability performance.

The present invention has been made in view of such circumstances, and an object thereof is to provide a toner supply roll having a small initial electric resistance and excellent durability against energization.

[0005]

To achieve the above object, a toner supply roll of the present invention comprises a shaft body and a toner supply roll provided with at least one layer formed on the outer peripheral surface of the shaft body. The innermost layer among the above layers is formed by using a conductive material containing a quaternary ammonium salt represented by the following general formula (1) as an ionic conductive agent. To take.

[0006]

[Chemical 2]

That is, the inventors of the present invention have conducted intensive studies centering on a quaternary ammonium salt which is an ionic conductive agent in order to obtain a toner supply roll having a smaller initial electric resistance and excellent durability against electric current. . As a result, among the four substituents bonded to N on the positive ion side of the quaternary ammonium salt,
When at least one is different from each other and at least one is an alkyl group having 4 to 12 carbon atoms, the charge amount (charge amount) of N at the center of the positive ion can be increased and transfer of charge is easy. The present invention has been achieved by finding that the charge distribution is varied, the initial electrical resistance can be reduced with a small amount of addition, and that the balance between positive ions and negative ions is good, so that the electrical durability is excellent.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION Next, embodiments of the present invention will be described in detail.

The toner supply roll of the present invention has, for example, as shown in FIG. 1, a single layer structure in which a soft urethane foam layer 2 is formed on the outer peripheral surface of a shaft body 1. In the present invention, the greatest feature is that the soft urethane foam layer 2 is formed by using a special conductive material obtained by adding a specific quaternary ammonium salt to a urethane raw material.

The shaft 1 is not particularly limited,
For example, a metal core made of a solid metal body, a metal cylindrical body having a hollow interior, and the like are used. Examples of the material thereof include stainless steel, aluminum, and plated iron.

Polyol and isocyanate are used as the urethane raw material for forming the soft urethane foam layer 2.

The above-mentioned polyol is not particularly limited as long as it is usually used as a urethane raw material, and examples thereof include olefin-based polyols such as polyether polyol, polyester polyol, polycarbonate polyol, polycaprolactone polyol, polybutadiene polyol and polyisoprene polyol. Etc. These may be used alone or in combination of two or more.

The above-mentioned isocyanate is not particularly limited as long as it is a polyisocyanate having two or more functional groups. For example, tolylene diisocyanate (TDI) [2,4-
Body, 2,6-body, mixture of 2,4-body and 2,6-body],
Hexamethylene diisocyanate (HDI), 4,4 '
-Diphenylmethane diisocyanate (MDI), carbodiimide-modified MDI, polymeric polyisocyanate, orthotoluidine diisocyanate (TODI),
Examples thereof include naphthylene diisocyanate (NDI), xylylene diisocyanate (XDI) and polymethylene polyphenyl isocyanate. These may be used alone or in combination of two or more. Among these, tolylene diisocyanate (TDI) is preferably used in terms of low hardness.

The amount of isocyanate used in the above polyol is determined by the isocyanate index (NC
The O index) is preferably set in the range of 90 to 120, and particularly preferably 100 to 110. The NCO index means the equivalent of isocyanate with respect to the total equivalent of 100 of raw material components having a hydroxyl group that reacts with an isocyanate group.

In addition to the polyol and the isocyanate, a foaming agent, a catalyst, a foam stabilizer, an antioxidant, a colorant, a flame retardant and the like may be appropriately blended in the urethane raw material.

Water is preferably used as the foaming agent. The content of water as the foaming agent is preferably in the range of 0.3 to 2.5 parts with respect to 100 parts by weight of the polyol (hereinafter abbreviated as "part").

Examples of the catalyst include tertiary amine catalysts, organometallic compounds and the like.

The above-mentioned tertiary amine catalyst is, for example,
Monoamines such as triethylamine (TEA) and N, N-dimethylcyclohexylamine (DMEDA): N,
N, N ', N'-tetramethylethylenediamine (TM
Diamines such as EDA): N, N, N ', N ", N"-
Triamines such as pentamethyldiethylenetriamine (PMDETA): Cyclic amines such as triethylenediamine (TEDA): Dimethylaminoethanol (DME)
Alcohol amines such as A): Ether amines such as bis (2-dimethylaminoethyl) ether (BDMEE). These may be used alone or in combination of two or more.

The amount of the tertiary amine catalyst compounded is preferably 0.1 to 3 parts with respect to 100 parts of the polyol.

Examples of the organometallic compounds include stannas octoate, dibutyltin diacetate, dibutyltin dilaurate, dibutyltin thiocarboxyate and the like. These may be used alone or in combination of two or more.

The amount of the organometallic compound compounded is preferably in the range of 0.05 to 0.5 parts per 100 parts of the polyol.

Examples of the foam stabilizers include silicone foam stabilizers (polyoxyalkylene-dimethylpolysiloxane copolymers) and non-silicone foam stabilizers.

The specific quaternary ammonium salt used together with the urethane raw material is represented by the following general formula (1).

[0024]

[Chemical 3]

The alkyl group having 4 to 12 carbon atoms may be linear, branched or cyclic, but is preferably linear in view of steric hindrance in the molecule. The above carbon number 4,
As the 6,8,12 alkyl group, specifically, a butyl group, a hexyl group, an octyl group, and a dodecyl group are preferable.

In the above general formula (1), the remaining alkyl groups represented by R ^{1 to} R ⁴ (alkyl groups having other than 4 to 12 carbon atoms) are not particularly limited, but the above 4 to 4 carbon atoms are included.
It preferably has 12 or less carbon atoms than the alkyl group of 12, and may be linear, branched or cyclic. Specific examples of such an alkyl group include the above R ^{1 to} R ⁴
When any one of these is an alkyl group having 4 carbon atoms, the remaining groups are preferably alkyl groups having 3 or less carbon atoms, for example, methyl group, ethyl group, propyl group and the like. When any one of R ^{1 to} R ⁴ is an alkyl group having 12 carbon atoms, the remaining group has 11 carbon atoms.
The following alkyl groups such as methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group, nonyl group, decyl group and undecyl group are preferable.

In the above general formula (1), the n-valent anion represented by X ^n- is not particularly limited, and examples thereof include 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, Br ⁻ , I ⁻ , and
ClO ₄ ⁻ , HSO ₄ ⁻ , and C ₂ H ₅ SO ₄ ⁻ are preferable.

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

As the quaternary ammonium salt represented by the general formula (1), any one of R ^{1 to} R ⁴ is an alkyl group having 4 to 12 carbon atoms, and the remaining three are methyl groups. Or a quaternary ammonium salt which is an ethyl group, or a quaternary ammonium salt in which any one of R ^{1 to} R ⁴ is an alkyl group having 4 to 12 carbon atoms and the remaining one is a methyl group or an ethyl group. It is preferably used.

The amount of the specific quaternary ammonium salt compounded with respect to the urethane raw material polyol (base polymer) is in the range of 0.01 to 10 parts with respect to 100 parts of the base polymer. It is preferable to set to, and particularly preferably 0.1 to 5 parts.
That is, the amount of the specific quaternary ammonium salt compounded was 0.
When it is less than 01 part, it becomes difficult to reduce the electric resistance to a desired value, and when it is more than 10 parts, compatibility with the base polymer is poor and blooming tends to occur easily.

In addition to the specific quaternary ammonium salt, an ionic conductive agent other than the quaternary ammonium salt may be used in combination with the conductive material. Furthermore, an electronic conductive agent may be used in combination with the ionic conductive agent.

Examples of the ion conductive agent other than the above specific quaternary ammonium salt include phosphoric acid ester, sulfonate, borate, phosphate, aliphatic polyhydric alcohol,
Examples thereof include aliphatic alcohol sulfate salts. These may be used alone or in combination of two or more.

Examples of the electron conductive agent include metal powders such as aluminum powder and stainless powder, and c-Zn.
_{O, c-TiO 2, c} -Fe 3 O 4, c-SnO 2 such as a conductive metal oxide, graphite, conductive powder such as carbon black. These may be used alone or in combination of two or more. The above "c-" means
It means to have conductivity.

The toner supply roll of the present invention can be manufactured, for example, by the following method. That is, first, as shown in FIG. 2, a cylindrical mold 21 having a length substantially equal to the axial length of the soft urethane foam layer 2 of the toner supply roll, and caps 22 and 23 for closing both ends of the cylindrical mold 21. A molding die composed of and is prepared. In this molding die, both ends of the cylindrical mold 21 are closed by the caps 22 and 23 and the shaft 1 is supported by the caps 22 and 23 in a state where the shaft 1 is positioned inside the cylindrical mold 21. As a result, a molding cavity 24 that gives the intended final roll shape (outer diameter) of the toner supply roll is formed in the cylindrical mold 21. Then, the above-mentioned polyol, a conductive agent and, if necessary, a catalyst,
After preparing a premix polyol prepared by blending a foaming agent and a foam stabilizer, a mixture of this premix polyol with isocyanate is injected into the molding cavity 24, and this is kept at a predetermined temperature (about 60 ° C.). It is foamed and cured by heating in an oven for a predetermined time (about 30 minutes). Then, by removing the mold, the shaft body 1 as shown in FIG.
It is possible to obtain a toner supply roll having a single layer structure in which the soft urethane foam layer 2 is formed on the outer peripheral surface of the.

The thickness of the soft urethane foam layer 2 is
Usually, it is 2 to 8 mm, preferably 3 to 6 mm.

The toner supply roll of the present invention is not limited to the single-layer structure as shown in FIG. 1 and may have a multi-layer structure of two or more layers. However, it is necessary that the innermost layer of the layers is formed using the special conductive material.

Next, examples will be described together with comparative examples.

First, prior to Examples and Comparative Examples, the following materials were prepared.

[Trifunctional polyol] EP manufactured by Mitsui Chemicals, Inc.
240

[Curing catalyst] Kaoizer N, manufactured by Kao Corporation
o. 31

[Foaming agent] water

[Foam stabilizer] Silicone-based foam stabilizer (L5366, manufactured by Nippon Unicar Co., Ltd.)

[Isocyanate] 2,4-toluene diisocyanate (TDI-100, manufactured by Mitsui Chemicals, Inc.)

[Ion Conducting Agent] Quaternary ammonium salt represented by the following formula (2)

[0045]

[Chemical 4]

[Ion Conducting Agent] Quaternary ammonium salt represented by the following formula (3)

[0047]

[Chemical 5]

[Electroconductive agent] Carbon black (Ketjenblack EC, manufactured by Lion Akzo)

[0049]

Example 1 A toner supply roll was produced by using a urethane raw material prepared by mixing the components shown in Table 1 below in the proportions shown in the same table, according to the production method shown in FIG. That is, first, the forming die shown in FIG.
A core metal to be the shaft body 1 (diameter 5 mm, made of SUS304)
Set. Then, a polyol, a conductive agent, a curing catalyst, a foaming agent and a foam stabilizer were blended in the proportions shown in Table 1 below to prepare a premix polyol, and then isocyanate was mixed with the premix polyol in a predetermined proportion. The required amount of the product was injected into the molding cavity 24 of the molding die. This is heated in an oven at 60 ° C. for 30 minutes to foam and harden, and then released from the mold to have a single layer structure toner in which a soft urethane foam layer (thickness 5.5 mm) is formed on the outer peripheral surface of the shaft body. A supply roll was prepared (see FIG. 1).

[0050]

Examples 2 to 5 Toner supply rolls were manufactured in the same manner as in Example 1 except that the kinds and blending ratios of the respective components were changed to those shown in Table 1 below.

[0051]

[Table 1]

[0052]

Comparative Example 1 A urethane raw material was prepared according to Example 1 described in JP-A-10-169641. That is, 20 parts of TDI-100 (Sumijour T-100 manufactured by Sumitomo Bayer Urethane Co., Ltd.) and propylene oxide and ethylene oxide were added to glycerin to give a molecular weight of 5
100 parts of polyether polyol (made by Asahi Glass Co., Ltd., Exenol 828), which was 000, 6.3 parts of 1,4-butanediol, 4 parts of a silicone-based surfactant (SF2935F, manufactured by Nippon Unicar Co., Ltd.), and dibutyltin dilaurate. 0.03 parts and modified aliphatic dimethylethylammonium sulfate [H (CH ₂ ) _4-20 C ₂ H ₅ N (C
_{H 3) 2 C 2 H 5} SO 4: molecular weight 466 to 550] 0.
A urethane raw material consisting of 5 parts was prepared. Then, using this urethane raw material, a toner supply roll was produced in the same manner as in Example 1.

[0053]

Comparative Example 2 A urethane raw material was prepared according to Example 2 described in JP-A-10-169641. That is, a urethane raw material was prepared in the same manner as in Comparative Example 1 except that 0.2 part of tetrabutylammonium borofluoride was used instead of 0.5 part of the modified aliphatic dimethylethylammonium sulfate. Then, using this urethane raw material, a toner supply roll was produced in the same manner as in Example 1.

[0054]

Comparative Example 3 A urethane raw material was prepared according to Example 3 described in JP-A-10-169641. That is, except that, in addition to 0.5 part of the above-mentioned modified aliphatic dimethylethylammonium sulfate, 0.015 part of a 33% by weight solution of sodium perchlorate (NaClO ₄ : molecular weight 122.5) in diethylene glycol monomethyl ester was used, A urethane raw material was prepared in the same manner as in Comparative Example 1. Then, using this urethane raw material, a toner supply roll was produced in the same manner as in Example 1.

Using the toner supply rolls of the example product and the comparative product thus obtained, the respective characteristics were evaluated according to the following criteria. The results are also shown in Tables 2 and 3 below.

[Electrical Resistance] The electrical resistance of the toner supply roll was measured by the metal roll electrode method as shown in FIG. That is, the load on both ends of the toner supply roll 31 is 4.
While pressing the metal roll 32 having a diameter of 30 mm with 9 N, the metal roll 32 was rotated in the direction of the arrow at a rotation speed of 60 rpm, and the toner supply roll 31 was rotated in the direction of the arrow along with the rotation of the metal roll 32. . Then, 100 is attached to one end of the toner supply roll 31.
A voltage of V was applied and the current value was measured to obtain the electric resistance value.

[Electrical Durability Test] The current value was measured 10 hours after the current was applied in the state shown in FIG. 3 to determine the increased number of electric resistance digits.

[0058]

[Table 2]

[0059]

[Table 3]

From the above results, it is understood that all of the example products have a small initial electric resistance and excellent current-carrying durability performance.

On the other hand, it can be seen that the comparative products have high initial electric resistance and poor durability.

[0062]

As described above, in the toner supply roll of the present invention, the innermost layer is formed by using the conductive material containing the specific quaternary ammonium salt. Then, at least one of the four substituents bonded to N on the positive ion side of the quaternary ammonium salt is different from each other, and at least one is an alkyl group having 4 to 12 carbon atoms, and therefore, the positive ion The charge amount (charge amount) of N at the center of the charge can be increased, the charge distribution can be easily performed, and the initial electrical resistance can be reduced with a small addition amount. Excellent balance due to good balance.

[Brief description of drawings]

FIG. 1 is a perspective view showing an example of a toner supply roll of the present invention.

FIG. 2 is a cross-sectional view showing an example of a method for producing a toner supply roll of the present invention.

FIG. 3 is an explanatory diagram showing a method for measuring electric resistance.

[Explanation of symbols]

1 axis 2 Soft urethane foam layer

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Kazunori Toyama             Tokai Rubber Works, Higashi 3-chome, Komaki City, Aichi Prefecture             Business (72) Inventor Takeyama Takeda             Tokai Rubber Works, Higashi 3-chome, Komaki City, Aichi Prefecture             Business F-term (reference) 2H077 AC04 FA13 FA25                 3J103 AA02 FA12 FA14 GA02 GA57                       GA58 GA60 HA20 HA60

Claims (7)

[Claims] 1. A toner supply roll comprising a shaft body and at least one layer formed on the outer peripheral surface of the shaft body, wherein the innermost layer of the above layers is used as an ionic conductive agent as described below. A toner supply roll formed using a conductive material containing a quaternary ammonium salt represented by the formula (1). [Chemical 1] 2. The general formula (1), wherein any one of R ^{1 to} R ⁴ is an alkyl group having 4 to 12 carbon atoms, and the remaining three are a methyl group or an ethyl group. Toner supply roll. 3. The general formula (1), wherein any one of R ^{1 to} R ⁴ is an alkyl group having a carbon number of 4 to 12, and the remaining one is a methyl group or an ethyl group. Toner supply roll. 4. The toner supply roll according to claim 1, wherein a conductive material in which an electronic conductive agent is used together with the ionic conductive agent is used. 5. The toner supply roll according to claim 1, wherein a conductive material obtained by adding a quaternary ammonium salt represented by the general formula (1) to a base polymer is used. . 6. The toner supply roll according to claim 5, wherein the base polymer is a urethane raw material polyol. 7. The amount of the quaternary ammonium salt compounded is
0.01 to 100 parts by weight of the base polymer
The toner supply roll according to claim 5, wherein the toner supply roll is set in a range of 10 parts by weight.