JPH0771441A - Roll using n-alkoxy alkylated nylon resin - Google Patents

Abstract

PURPOSE:To provide a conductive roll for applying the potential of the preset polarity to a charged body such as a photosensitive drum or a recording medium, regarding an electrophotographic copying machine or the like. CONSTITUTION:This roll is coated with a composite of stabilized N-alkoxy alkylated nylon resin featuring that an oxide and a hydroxide of alkali metal or earth metal, and the metallic salt thereof are blended with N-alkoxy alkylated nylon resin. As a result, the stability of the resin particularly against heat can be provided and thus the processability thereof can be improved. In addition, a process including kneading, extrusion and hot melt bonding can be employed. Thus, the non-use of a solvent, cost reduction or the like can be ensured for a process. Furthermore, bridging (three-dimensional) due to stimulation with heat, current (due to power supply) or the like during use can be prevented, even with a roll using the N-alkoxy alkylated nylon resin, and the quality thereof including flexibility, electric characteristics and hydrophilic property can be stabilized.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a conductive roll for applying an electric potential of a predetermined polarity to an object to be charged such as a photosensitive drum or a recording medium in an electrophotographic recording device or the like.

[0002]

2. Description of the Related Art An electrophotographic recording apparatus widely used in a copying machine, a laser beam printer, etc. is generally equipped with a drum-shaped photosensitive member (hereinafter referred to as a photosensitive drum).
The photosensitive drum is charged and exposed to form an electrostatic latent image, a toner is attached and developed according to the latent image on the photosensitive drum, and then the toner on the photosensitive drum is recorded. The toner is transferred to a recording medium such as paper and transferred, and then the photosensitive drum is neutralized to a predetermined potential and the toner remaining on the photosensitive drum is cleaned to prepare for the next recording. Also, the toner carried on the recording medium by the transfer is
It is fixed on the recording medium by being melted and pressure-bonded, thereby completing a series of recording operations.

In this case, a charging roller for applying a predetermined potential to the charging area of the photosensitive drum of the electrophotographic recording apparatus, a developing roller for transferring the toner to the photosensitive drum, and a transfer area are transferred. As a conductive roll such as a transfer roll for imparting a predetermined electric potential to a recording medium, or a charge-eliminating roll for uniformizing the charged area of the photosensitive drum after transfer to a constant electric potential, a good conductivity is usually used. Base shaft, a base layer made of rubber having good conductivity provided on the outer periphery of the shaft, and a base layer for adjusting the electric resistance of the roll and preventing contamination of the photosensitive drum and recording medium. It is composed of a single layer or a plurality of conductive film layers.

As the conductive elastic material forming the base layer, a non-foamed or foamed conductive rubber composition and a conductive polyurethane foam can be used. Among these, as the rubber component constituting the non-foamed conductive rubber composition, butadiene rubber, nitrile butadiene rubber, chloroprene rubber, styrene butadiene rubber, ethylene propylene rubber, isoprene rubber, polynorbornene rubber, etc., normal rubber or styrene -Butadiene-styrene (SBS), styrene-butadiene-styrene hydrogenated product (SEBS) and the like thermoplastic rubbers can be used, but are not particularly limited, but these rubbers, particularly solid butadiene rubber / liquid It is preferable that the polyisoprene rubber is mixed at a ratio of about 10/90 to 50/50, and a conductive material is mixed with this to form a base layer, which has a low hardness and a small compression set. To improve the adhesion between the roll and the charged body such as the photosensitive drum. It can be.

The foamed conductive rubber is not particularly limited, but ethylene propylene rubber mixed with a conductive material, a foamed copolymer rubber of epichloropidrin and ethylene oxide, or epichlorohydrin is used. A foam or the like in which a conductive material is mixed with a copolymer rubber of ethylene oxide and ethylene oxide can be preferably used.

As the conductive material to be blended with these rubber compositions, conductive powders and carbon powders such as carbon black, graphite, metals and various conductive metal oxides (tin oxide, titanium oxide, etc.) are used.
Various conductive fibers such as bon fibers and metal oxide short fibers can be used. The compounding amount is 100
It can be 3 to 100 parts by weight, especially 5 to 50 parts by weight, and the volume resistance of the base layer is 10 ¹ to 10 ⁷ Ω · cm.
It is preferable to adjust the degree. The base layer can be formed by a known vulcanization molding method, and its thickness is appropriately set according to the application of the roll, etc.
~ 20mm, and its hardness is 20 ~ 9 with Asuka-C
It is preferably 0 degree, particularly 30 to 70 degrees.

A single-layer or multiple-layer conductive film layer is provided on the base layer, and the conductive film layer has a volume resistance of 1 ×.
It has a thickness of about 2 to 300 μm at about 10 ⁷ to 10 ¹¹ Ω · cm. In order to prevent the conductive film layer from adhering to the photosensitive drum or to prevent it from being contaminated, or to improve the electrical characteristics of the conductive film layer, or toner by a charging roll.
In order to prevent the toner from fusing to the photosensitive drum, another conductive film layer is often provided as the outermost layer. The volume resistance of the latter conductive film layer is also 1 × 10 ⁷ to 1 × 10 ¹¹ Ω ·
It has a thickness of about 1 to 100 μm in cm.

N-alkoxyalkylated nylon is used as the material for the conductive film layers of these rolls, but N-methoxymethylated nylon obtained by modifying 6 nylon is generally used. This is because this resin is soft and there is no adverse effect such as contamination or adhesion to the photosensitive drum,
This is because it has characteristics such as relatively low volume resistance (about 1 × 10 ⁹ Ω · cm). And when this resin is used as the outermost conductive film layer, as the inner conductive film layer,
In many cases, epichlorohydrin rubber or polyurethane rubber is used, and it plays a role of preventing the inner conductive film layer from adhering to the photosensitive drum and preventing contamination.

However, such an N-alkoxyalkylated nylon resin is demethanoized when heated in the presence of an acid.
Reaction, causing intermolecular cross-linking and three-dimensionalization, but N-
In the manufacturing process of the alkoxyalkylated nylon resin, it is difficult to completely remove the acid from the resin because an acid such as phosphoric acid is used, and a trace amount of the acid remains. Therefore, there is a problem that a crosslinking reaction easily occurs when processing this resin or when using a product using this resin.

That is, the N-alkoxyalkylated nylon resin can be dissolved in methanol or the like and applied, but when it is heated to a temperature above the melting point (about 155 ° C.) to be melted and processed, for example, an additive is mixed. In addition, when it is attempted to make a film by extrusion, there is a drawback that it becomes three-dimensional by cross-linking and loses plasticity, and finally becomes powder.

As described above, when the N-alkoxyalkylated nylon resin is crosslinked, the tensile strength and tear strength increase, and the electric resistance increases. In particular, in the conductive rolls such as the charging roll, the developing roll, the transfer roll, and the discharging roll, which are the objects of the present invention, as described above, the acid remaining in the resin Due to the influence, the N-alkoxyalkylated nylon resin starts to be cross-linked during the use of the product due to heat or electrical stimulation, and the characteristics change, so that the intended purpose is often not met.

[0012]

DISCLOSURE OF THE INVENTION The present invention is directed to the thermal stabilization of N-alkoxyalkylated nylon, and specifically, it has been improved by using N-alkoxyalkylated nylon resin. The purpose is to provide a conductive roll.

[0013]

The present invention adopts the following constitution in order to achieve the above object. That is,
A first aspect of the present invention is a stabilized N-alkoxyalkylated nylon resin characterized by blending an N-alkoxyalkylated nylon resin with an oxide of an alkali metal or an earth metal, a hydroxide and a metal salt thereof. It relates to a roll coated with a resin composition.

A second aspect of the invention is a roll having a surface layer of N-alkoxyalkylated nylon resin, which is composed of a laminate with a synthetic resin and / or rubber,
Stabilized N characterized by blending an oxide of an alkali metal or an alkaline earth metal, a hydroxide and a metal salt thereof into the synthetic resin and / or rubber laminated on the N-alkoxyalkylated nylon resin. The present invention relates to an alkoxyalkylated nylon resin laminate roll.

Examples of the alkali metal and alkaline earth metal used here include lithium, sodium, potassium, rubidium, beryllium, magnesium, calcium, strontium and barium. And metal salts such as these oxides, hydroxides, carbonates and phosphates are effective, and further salts of organic acids such as various carboxylic acids, thiocarboxylic acids and dithiocarboxylic acids are also effective.

The amount of these oxides, hydroxides, metal salts, etc. added is 0.1 parts by weight or more, preferably 1 to 100 parts by weight, based on 100 parts by weight of the N-alkoxyalkylated nylon resin. Even if the amount is 0.1 parts by weight or less, the effect is not sufficient, but it is better to add a larger amount in view of long-term stabilization, but if it is too large, for example, the physical properties of the film are deteriorated. Comes out.

[0017]

As described above, since an acid such as phosphoric acid is used in the manufacturing process of N-alkoxyalkylated nylon resin, a trace amount of acid remains in this resin. Therefore, as described above, there is a problem that crosslinking (three-dimensional reaction) is likely to occur when the resin is processed or a product using the resin is used.

However, in the above-mentioned various rolls,
As a material for the conductive film layer, especially N-
Methoxymethylated nylon is preferred. This is because the resin is soft, there is no adverse effect such as contamination or adhesion to the photosensitive drum, and the volume resistance is relatively low (1
This is because there are features such as × 10 ⁹ Ω · cm).
When heated in the presence of an acid, the N-alkoxyalkylated nylon resin causes a demethanol reaction and crosslinks between molecules. However, since an acid such as phosphoric acid is used in the manufacturing process of the N-alkoxyalkylated nylon resin, it is difficult to completely remove the acid from the resin, and a trace amount of the acid remains. Therefore, a crosslinking reaction is likely to occur when processing this resin or when using a product using this resin.

That is, this cross-linking has the drawback that the resin loses plasticity, and when it is subjected to a shearing force such as kneading or extrusion, it is finally pulverized. Further, when the product is cross-linked after being made into a product, the tensile strength and tear strength increase, and the electric resistance increases. However, when a roll of uncrosslinked resin is used in a printer and crosslinking occurs during use, an image defect occurs, and the toner is easily rubbed on the photosensitive drum surface in contact with the charging roll. However, there is a drawback that this is fused to the photosensitive drum and an image defect occurs.

The present invention, in order to neutralize the residual acid in the resin used as the surface material of various conductive rolls, in the first aspect of the invention, an N-alkoxyalkylated nylon resin is used. Is mixed with an oxide, hydroxide, carbonate, or phosphate of an alkali metal or an alkaline earth metal, the second of which is that the resin or rubber on the side which is in direct or indirect contact with this resin contains an alkali. It is a compound in which oxides, hydroxides, carbonates and phosphates of metals or alkaline earth metals are added, and the acid in the N-alkoxyalkylated nylon resin is sequentially transferred to be neutralized. The second method is particularly effective when an acid component is present in the layers to be laminated.

[0021]

EXAMPLES The present invention will be described in more detail with reference to examples. (Examples 1 to 4 and Comparative Examples 1 and 2) N-methoxymethylated nylon resin (trade name: resin, manufactured by Teikoku Chemical Industry Co., Ltd.) was used, and conductive titanium oxide was dispersed and compounded as an example of the conductive material. The test was carried out by taking as an example. The Brabender Plastomill used for kneading is from Toyo Seiki Seisakusho.

Now, N-methoxymethylated nylon resin, and a mixture of 100 parts by weight of N-methoxymethylated nylon resin and 30 parts by weight of conductive titanium oxide were kneaded in a Brabender-Plastomill without solvent. By the way
In both cases, the resin was cross-linked and shattered, and kneading could not be performed sufficiently. However, when 1 part by weight and 5 parts by weight of calcium hydroxide were mixed with the above-mentioned number of parts, respectively,
The viscosity hardly increased, and it was possible to sufficiently knead with a Brabender-Plastomill or a continuous kneading extruder (KCK) (manufactured by Keishi Kei Co., Ltd.).

(Example 5 / Comparative Example 3) 100 parts by weight of N-methoxymethylated nylon resin and 30 parts of conductive titanium oxide.
A mixture with 1 part by weight was dissolved in methanol / toluene and coated on the urethane rubber surface as the outermost layer of the charging roll of the laser beam printer. When this was heated at 80 ° C. for 8 days, this film was crosslinked and the electric resistance increased. When this roll was used in a printer, an image defect occurred.

On the other hand, 5 parts of calcium hydroxide was added to the above composition.
What was added by weight was coated on the urethane rubber surface in the same manner as above. The film was not cross-linked even if it was heated at 80 ° C. for 20 days, and a good screen was obtained even when this roll was used in a printer. The electric resistance did not rise.

Example 6 and Comparative Example 4 100 parts by weight of N-methoxymethylated nylon resin and 30 parts of conductive titanium oxide.
A mixture with 1 part by weight was dissolved in methanol / toluene and coated on the urethane rubber surface as the outermost layer of the charging roll of the laser beam printer. When this charging roll was attached to a laser beam printer and a continuous current passing test was conducted, the N-methoxymethylated nylon resin layer began to crosslink and became hard. This charging roller comes into contact with the photosensitive drum and rotates following it, but if the surface of the charging roller is hard, the toner is easily rubbed against the surface of the photosensitive drum, which is fused to the photosensitive drum and appears in the image. Will end up. Further, the cross-linking of the resin layer increased the electric resistance, resulting in an image defect.

On the other hand, 5 parts by weight of calcium hydroxide was added to a mixture of 100 parts by weight of N-methoxymethylated nylon resin and 30 parts by weight of conductive titanium oxide, and dissolved in methanol / toluene. In the case where the urethane rubber surface was coated as the outermost layer of the charging roller of the beam printer, the film did not crosslink even in the same test as described above, and the toner was not welded to the photosensitive drum. There wasn't. In addition, no image defect occurred.

(Examples 7 to 32 and Comparative Examples 5 to 6) 100 parts by weight of N-methoxymethylated nylon resin was mixed with various additives shown in Table 1 and kneaded with a Brabender-Plastomill to form a shaft. The increase in torque was read from the chart. The results are shown in Table 1. Minimum torque is 5 kg / c
It was judged that the crosslinking had started when m increased, and in the table, ⊚ indicates an example in which the crosslinking did not occur for 1 hour or more, and ∘ indicates an example in which the crosslinking did not occur for 10 minutes or more.

[0028]

[Table 1]

(Examples 33 and 34 and Comparative Example 7) N-methoxyethylated nylon resin was treated with a Brabender-extruder (manufactured by Toyo Seiki Seisakusho Co., Ltd.) and 160 N-methoxyethylated nylon resin.
It was melted by heating to ℃ and extruded on a conductive rubber roll.
This resin could not be extruded onto a rubber roll because it was crosslinked in the extruder and shattered.

On the other hand, 100 parts by weight of N-methoxymethylated nylon resin and 5 parts by weight of calcium hydroxide were kneaded by a KCK continuous kneading extruder to be pelletized, and the rubber roller was applied by a Brabender extruder as described above. -It was possible to extrude a clean film without cross-linking when extruded onto the film. Also, not only 5 parts by weight of calcium hydroxide but also 30 parts by weight of conductive tin oxide were kneaded into 100 parts by weight of N-methoxymethylated nylon resin with a KCK continuous kneading extruder to form pellets, and the same procedure as above was performed using the Brabender. When extruded on a rubber roll with an extruder, a clean film could be extruded without cross-linking.

[0031]

Since the present invention has the above-mentioned constitution,
The stability of the alkoxyalkylated nylon resin is brought about especially against heat. Therefore, the workability of the N-alkoxyalkylated nylon resin is brought about, and the processing such as kneading, extrusion and hot melt adhesion can be performed. It has become. Therefore, it is possible to use a solvent-free process, reduce costs, and the like. Further, even in a roll using an N-alkoxyalkylated nylon resin, cross-linking (three-dimensional) due to a stimulus such as heat and electricity (by energization) during use can be prevented, resulting in flexibility, electric characteristics, It was possible to stabilize properties such as hydrophilicity.

Claims (2)

[Claims] 1. Stabilized N characterized by compounding an N-alkoxyalkylated nylon resin with an oxide of an alkali metal or an earth metal, a hydroxide and a metal salt thereof.
A roll coated with an alkoxyalkylated nylon resin composition. 2. A roll comprising a N-alkoxyalkylated nylon resin as a surface layer, which is composed of a laminate with a synthetic resin and / or rubber, wherein the synthetic resin is laminated on the N-alkoxyalkylated nylon resin. And / or in the rubber, an oxide of an alkali metal or an alkaline earth metal,
A stabilized N-alkoxyalkylated nylon resin laminate roll comprising a hydroxide and a metal salt thereof.