JPH10329970A - Conveyance roll and its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To keep a friction factor at a high level and improve paper feed performance by forming an undercoat layer and a topcoat layer with a conductive resin layer on the surface of a core roll, setting the surface resistance value of the core roll to a specific value or below, and setting the surface toughness to a specific value or above. SOLUTION: An undercoat layer 2 made of a conductive epoxy resin layer is uniformly formed by dipping on the surface of a core roll 1, and various grains are formed into a one-layer or two-layer high-density uniform grain layer 3 by pressing while the undercoat layer 2 is still kept at the half-hardened state. A topcoat layer 4 made of a uniform-thickness conductive epoxy resin layer is provided by dipping on the grain layer 3. The surface resistance value of the core roll 1 is set to 10<8> Ω or below, and the surface roughness is set to 15 μm or above.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to OA equipment represented by electrophotographic equipment such as copiers, printers, facsimiles, scanners, etc., electric appliances, automatic ticket gates, ticket vending machines, ATMs, and the like.
The present invention relates to a roll (hereinafter, referred to as a transport roll) for transporting and transporting a conveyed sheet and a transparent film for an overhead projector (OHP) in a (financial terminal dispensing apparatus) or a printing machine.

[0002]

2. Description of the Related Art Conventionally, paper sheets and overhead projectors (OH) have been used in OA equipment, electrical appliances, automatic ticket gates, ticket vending machines, ATMs, printing machines, and the like.
A transport roll for feeding and transporting a transparent film or the like for P) is used, but a high performance is required for the transport roll due to recent technological innovation. Especially color copiers,
In the case of a color printer, etc., if the accuracy of the transport rolls is poor, color shift will occur during printing, so the disturbance of the paper feed pitch is small, the paper feed performance is stable against changes in temperature and humidity, and paper dust etc. In terms of performance that hardly adheres, a high level is desired.

Conventionally, there has been known a transport roll in which the surface friction coefficient is increased to improve the paper feeding performance. For example, a transport roll made of a metal roll having a rough surface by knurling or sandblasting, Alternatively, a surface roughened by coating with ceramic (see Japanese Utility Model Application Laid-Open No. 55-63339), or a roll obtained by applying liquid honing or dry honing to the outer peripheral surface of a shaft (Japanese Utility Model Application Laid-Open No. 61-44451). And the like are known.

[0004] These rolls are all inadequate in terms of paper feeding performance, and also have manufacturing problems. In addition, there is a case where surface irregularities are relatively small and the dimensional accuracy of the surface is not high. In any case, none of the required performances can be satisfied.

[0005] Further, on the outer periphery of the roll shaft, there is a paper feed roll in which a plurality of rubber-like elastic ring bodies are mounted at appropriate intervals or in close contact with each other (Japanese Utility Model Application Laid-Open No. 62-65434).
Reference).

However, although this one has higher surface dimensional accuracy than providing a rubber-like elastic body integrally on a shaft, it has a problem in close contact or mounting, and further has poor paper feeding performance, and paper dust and the like are not generated. There is also the problem of easy adhesion.

Further, there is a transport roll in which abrasive grains such as alumina are fixed on the surface of a metal core roll with a binder such as epoxy resin (see Japanese Utility Model Application Laid-Open No. 61-119549).

However, such a roll also has higher surface dimensional accuracy than providing a rubber-like elastic body on a shaft, and
If a large amount of paper, such as recycled paper or bond paper, that easily generates paper dust is passed though it is difficult for paper dust to adhere, the friction coefficient will decrease due to the adhesion of the paper dust, resulting in paper transport errors and color misalignment during printing. There is a problem that occurs.

[0009]

The above-described conventional transport rolls attempt to enhance the paper feeding performance by increasing the friction coefficient of the surface. Good adhesiveness, color misregistration and good dimensional accuracy have not been obtained.

The present invention has been made in view of the above-mentioned conventional circumstances, and has high surface dimensional accuracy and no color shift.
Even when transporting paper that easily generates paper dust, such as bond paper,
There is no problem of adhesion of paper dust etc. such as there is no need to remove paper dust etc. attached to the roll surface with cleaning paper etc.
An object of the present invention is to provide a transport roll that can maintain a high coefficient of friction at a high level, and therefore has good paper feeding performance and is easy to manufacture.

[0011]

According to a first aspect of the present invention, there is provided an undercoat layer provided on a surface of a core roll, a particle layer comprising particles fixed to the undercoat layer, and A top coat layer covering the particle layer, wherein the undercoat layer and the top coat layer are formed of a conductive resin layer, the surface resistance of the roll is 10 ⁸ Ω or less, and Roughness RZ is 15
The transport roll is characterized in that it has a thickness of at least μm.

Here, it is preferable that a vertex of a portion of the top coat layer covering the particles protrudes 5 to 40 μm on average in a radial direction from a portion of the particle layer covering the particles.

It is preferable that the conductive resin layer is made of an epoxy resin layer.

Further, the conductive resin layer comprises a dispersant such as at least one kind of a high molecular polyester ether type amine salt, an organic metal complex type coupling agent and a conductive material such as conductive carbon. It is preferred to contain.

The average particle diameter of the particles forming the particle layer is 20 to 60 μm, and more preferably 25 to 50 μm.
Is more preferable, and most preferably about 30 μm.

According to a second aspect of the present invention, there is provided a step of providing an undercoat layer made of a conductive resin layer on the surface of a core roll, and a step of fixing particles to the undercoat layer to form a particle layer. And a step of forming a top coat layer made of a conductive resin layer covering the particle layer.

Here, it is preferable that the undercoat layer and the topcoat layer are formed by a dipping method.

In the transport roll of the present invention, for example, as shown in FIG. 1, the undercoat layer 2 made of a conductive epoxy resin layer is uniformly formed on the surface of a core roll 1 by, for example, dipping. Then, various particles are fixed by, for example, a pressure bonding method, a fluid immersion method, or a spraying method while the undercoat layer 2 is in a semi-cured state. At this time, since the undercoat layer is in a semi-cured state, the deformation of the undercoat layer is prevented, and the film thickness can be kept uniform without unnecessary particles sticking. Further, by removing excess particles that are not fixed to the undercoat layer by air blowing at a predetermined air pressure, one layer or two layers are removed.
A high-density and uniform particle layer 3 can be formed on the undercoat layer 2. The top coat layer 4 made of a conductive epoxy resin layer having a uniform film thickness is again formed on the particle layer 3 by, for example, a dipping method.
Is provided, it is possible to prevent the particles from falling off during the operation of the roll, and it is possible to obtain a transport roll having high roundness, small runout, and extremely high surface dimensional accuracy.

Here, the particles forming the particle layer of the present invention include inorganic powders such as alumina, silicon carbide (carborundum), cubic boron nitride and diamond, stainless steel, and the like.
Examples include metal powders such as bronze and brass.

The conductive resin layer is formed by blending at least a conductive material with, for example, urethane resin or acrylic resin in addition to epoxy resin.

In order to form a resin layer using these resins, the above resin is diluted with a diluent such as methyl ethyl ketone, ethyl acetate, xylene or toluene.

Examples of the conductive material include conductive carbon, conductive nickel, conductive zinc oxide, and conductive whiskers. The content of the conductive material may be blended so that the surface resistance of the roll is 10 ⁸ Ω or less.

The formation of the undercoat layer and the topcoat layer made of such a conductive resin layer is not limited to the dipping method, and any appropriate means capable of forming a layer having a uniform thickness can be used. For example, a spray coating method, a roll coating method and the like can be exemplified.

Further, since the transport roll of the present invention comprises only a core roll provided with an undercoat layer, a particle layer and a top coat layer, it is easy to manufacture, has good dimensional accuracy, and causes color shift. Since the surface is rough, the coefficient of friction is high and the paper feeding performance is good. Further, the resin coating layer contains a dispersant such as a high molecular weight polyester ether type amine salt and an organic metal complex type coupling agent and a conductive material such as conductive carbon in the resin. There is no electrification, and paper powder and the like hardly adhere.

Further, since the transport roll of the present invention obtains the paper feed performance by the friction coefficient due to the surface roughness,
Stable paper feed performance is obtained even with changes in temperature and humidity. Also, although it has a rough surface because it has a resin coat layer on the surface, it can be used to transport transparent films for overhead projectors (OHP). Does not hurt.

In the present invention, for example, particles having a particle diameter of 20 to 60 μm, preferably 25 to 50 μm, and most preferably about 30 μm are obtained in order to obtain a rough surface.
m, preferably in a resin coat layer having a thickness of 10 to 25 μm. Thereby, the top of the portion of the top coat layer that covers the particles protrudes 5 to 40 μm on average in the radial direction from the portion that covers between the particles of the particle layer, so that good paper feeding performance can be obtained.

The core roll used for the transporting roll of the present invention may be a conventionally used core roll, for example, a metal core roll made of steel, stainless steel, aluminum or the like, or a resin roll made of vinyl chloride, polyacetal or the like. Core rolls can be used.

[0028]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described with reference to the drawings based on embodiments, but the present invention is not limited to the embodiments unless it is contrary to the gist of the present invention.

(Examples 1 and 2) In Examples 1 and 2, the epoxy resin coating liquid used for the undercoat layer and the top coat layer was prepared as follows.

First, a flexible epoxy base material, a conductive carbon in a ratio shown in Table 1 below with respect to the base material, and a polyester ether amine salt dispersant in a ratio shown in Table 1 below with respect to the base material were used. Were individually mixed and dispersed by an ultrasonic wave or a ball mill to prepare each coating solution stock solution.

Each of the stock solutions was diluted with 200 wt% of methyl ethyl ketone with respect to the main component of the flexible epoxy to obtain epoxy resin coating solutions (coating solutions) used in Examples 1 and 2.

Next, a metal core roll is dipped in each coating solution by a dipping method, pulled up at a speed of 120 mm / min, and is applied to a surface of the metal core roll having a thickness of about 13 μm to 2 μm.
A uniform undercoat layer of 0 μm was formed. afterwards,
The metal core roll was air-dried at room temperature for about 5 minutes to bring the undercoat layer into a semi-cured state.

Next, alumina particles having an average particle diameter of 30 μm were fixed to the entire undercoat layer by a pressure bonding method. Then, the alumina particles not fixed to the undercoat layer were removed by air blow to form a dense and uniform alumina particle layer.

Next, this was thermally cured at 120 ° C. for about 20 minutes, and cooled until the metal core roll reached room temperature. Thereafter, a core roll having an alumina particle layer was further immersed in each coating solution by a dipping method, and 120 mm
The film was pulled up at a speed of / min, and a top coat layer having a thickness of about 15 μm to 21 μm was formed on the alumina particle layer, respectively, and thermally cured at 120 ° C. for about 60 minutes.

The transport roll has a uniform film thickness because the undercoat layer and the top coat layer are formed by the dipping method.
The alumina particles adhered to the layer were dense and free of unevenness, so that the roll had high roundness, small run-out, and extremely high surface dimensional accuracy, so that color shift did not occur.

Further, since the undercoat layer and the top coat layer are a carbon-containing conductive epoxy resin layer in which the undercoat layer and the top coat layer are uniformly dispersed, the roll surface is not charged and there is no problem of adhesion of paper powder and the like. Had good paper feeding performance.

(Comparative Examples 1 to 6) In Comparative Examples 1 to 6, epoxy resin coating solutions used for the undercoat layer and the top coat layer were prepared as follows.

First, a dispersant of a polyester ether type amine salt and conductive carbon in a ratio shown in the following Table 1 are mixed with a flexible epoxy main agent and dispersed by an ultrasonic wave or a ball mill. , Various stock solutions were prepared.

Next, each of the stock solutions was diluted with 200% by weight of methyl ethyl ketone with respect to the main component of the flexible epoxy to obtain coating solutions used in Comparative Examples 1 to 6.

The transport rolls of Comparative Examples 1 to 6 were produced in the same manner as in Examples 1 and 2, except that these coating solutions were used.

Comparative Example 7 EPDM Rubber (Mitsui EPT-
4010) 6 parts by weight of a peroxide crosslinking agent (Parkmill D-40) and carbon black (HA)
F black) 80 parts by weight, press vulcanization and diameter 1
It was formed into a roll having a length of 2 mm and a length of 300 mm. The rubber hardness of the molded product was 50 ° on a JIS A scale.

Comparative Example 8 A urethane resin coating agent was
A dispersion in which alumina particles having an average particle diameter of 30 μm are dispersed is used as a coating liquid, and this coating liquid is sprayed onto a metal core roll having a diameter of 12 mm and a length of 300 mm to which a primer of about 5 μm is applied, and a urethane resin A roll formed with a mixed layer of alumina and alumina particles was produced.

(Comparative Example 9) A coating composition of a silicone resin in which alumina particles having an average particle diameter of 30 μm were dispersed was used as a coating composition, and this coating composition was coated with a primer of about 5 μm and had a diameter of 12 mm and a length of 12 μm. A 300 mm-thick metal core roll was sprayed onto the metal core roll to produce a roll on which a mixed layer of silicone resin and alumina particles was formed.

[0044]

[Table 1]

(Test Example 1) Examples 1 and 2 and Comparative Example 1
The electrical resistance of the resin film and the surface resistance of the transport roll were measured for each of the transport rolls of Nos. 1 to 6. Table 2 shows the results. In measuring the resistance value, the distance between the electrodes was 10 m.
m, and the applied voltage was 10 V.

[0046]

[Table 2]

From the results in Table 2, it can be seen that, when the resin film itself is electrically conductive and the dispersant is not added, when the resin film is rolled,
It was confirmed that there were some that did not show conductivity.

Test Example 2 The transport rolls of Examples 1 and 2 were evaluated for antistatic function and compared with the transport rolls of Comparative Examples 1 to 6. The result is shown in FIG.

Here, the evaluation of the antistatic function was performed by measuring the surface charging potential as described below.

With plain paper wound around each transport roll under a predetermined load, each transport roll was idled at 250 rpm for 1 minute, and then the charged potential on the surface was measured every second. During the measurement, the roll was kept rotating, and after 20 seconds from the start of the measurement, air was blown to remove the paper dust.

From the results shown in FIG. 2, it was confirmed that the transport rolls of Examples 1 and 2 had a lower surface charge potential than those of Comparative Examples 1 to 5, and the transport roll of Example 2 was particularly excellent. Was done. Thereby, the transport rolls of Examples 1 and 2
It was confirmed that it was hardly charged and hardly affected by paper dust. This indicates that the surface resistance of the roll is 1 from the results in Table 2.
0 is less than or equal to ^{8 Ω} can be said a factor.

(Test Example 3) Examples 1 and 2 and Comparative Example 1
Paper powder was adhered to each of the transfer rolls No. to No. 9 by a 100,000 sheet passing test, and the friction coefficient in that state was measured and compared with the initial friction coefficient. Further, the friction coefficient after removing the attached paper powder was compared. Table 3 shows the results.

[0053]

[Table 3]

From the results shown in Table 3, it was found that a surface roughness RZ of 15 μm or more was required to obtain a good initial friction coefficient. Furthermore, in order to improve the paper powder adhesion prevention function of the roll, the roll surface is conductive, and
It has been found that a surface roughness RZ of 15 μm to 28 μm is suitable. Further, as a result, it was confirmed that the transport roll of Example 2 was particularly excellent.

Test Example 4 The roundness of the transport roll of Example 2 was measured. Also, for comparison, Comparative Examples 7 to 9
, And the roundness of the metal core roll itself was measured. Table 4 shows the results.

[0056]

[Table 4]

From the results shown in Table 4, the roll of Example 2 had remarkably high roundness, small run-out, and excellent precision as compared with the rolls of Comparative Examples 7 to 9.

[0058]

As described above, the transport roll of the present invention has a high level of paper powder adhesion preventing function which is not available in transport rolls using generally known inorganic abrasive grains, and has a high precision. In this case, color shift does not occur, and the paper can be stably fed.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating a transport roll according to an embodiment of the present invention.

FIG. 2 is a diagram illustrating a surface charging potential of a transport roll according to an example of the present invention.

[Explanation of symbols]

 1 core roll 2 undercoat layer 3 particle layer 4 topcoat layer

 ──────────────────────────────────────────────────続 き Continued from the front page (72) Inventor Yuta Suzuki 2-3-6 Shirite, Tsurumi-ku, Yokohama-shi, Kanagawa Prefecture

Claims (7)

[Claims] 1. An undercoat layer provided on a surface of a core roll, a particle layer made of particles fixed to the undercoat layer, and a top coat layer covering the particle layer, wherein the undercoat layer The top coat layer is formed of a conductive resin layer, the surface resistance of the roll is 10 ⁸ Ω or less, and the surface roughness RZ is 15 μm.
A transport roll characterized by the above. 2. The method according to claim 1, wherein a vertex of a portion of the top coat layer covering the particles protrudes 5 to 40 μm on average in a radial direction from a portion of the particle layer covering between the particles. Transport roll. 3. The transport roll according to claim 1, wherein the conductive resin layer comprises an epoxy resin layer. 4. The dispersant according to claim 1, wherein the conductive resin layer is formed of at least one kind of a polymer polyester ether amine salt, an organic metal complex coupling agent, or the like. And a conductive material such as conductive carbon. 5. The particle according to claim 1, wherein the particles forming the particle layer have an average particle diameter of 20 to 60 μm.
m. 6. A step of providing an undercoat layer made of a conductive resin layer on the surface of a core roll, a step of fixing particles to the undercoat layer to form a particle layer, and a step of forming a conductive layer covering the particle layer. Forming a top coat layer made of a resin layer having the following formula: 7. The method according to claim 6, wherein the undercoat layer and the topcoat layer are formed by a dipping method.