JP2001341862A - Paper feeding roller - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a paper feeding roller having high abrasion resistance and high coefficient of friction, and capable of being stably used for a long period. SOLUTION: An annular elastic body mounted on an outer peripheral face of a core body is composed of two layers, that is, an outer layer formed by a non-foaming layer and an inner layer formed by a foaming layer, or three layers including an innermost layer formed by a non-foaming layer to improve the fastening to the core body, in addition two the outer layer and the inner layer.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to friction devices such as OA equipment such as copiers, facsimile machines and printers, or automatic teller machines (ATMs), exchange machines, counters, vending machines, cash dispensers (CDs) and the like. The present invention relates to a paper feed roller used in an apparatus having a paper feed mechanism (including a thin-sheet-like material other than paper) using a paper feed mechanism, and more particularly, to a structure and a configuration of an annular elastic body of the paper feed roller.

[0002]

2. Description of the Related Art A paper feed roller is formed by mounting an annular elastic body made of rubber, elastomer, or the like on the outer peripheral surface of a core body. Layer.

However, the conventional paper feed roller has the following problems. (1) Because the contact time with paper is short, it is impossible to stably transfer the conveying force to the paper. (2) A transport trouble is likely to occur due to a temporal decrease in the friction coefficient of the surface of the annular elastic body caused by paper dust or the like. (3) The speed of the paper feed mechanism cannot be increased because the contact time with paper is short.

[0004]

SUMMARY OF THE INVENTION In view of the above problems, an object of the present invention is to provide a paper feed roller having high wear resistance and a high coefficient of friction, which can be used stably for a long period of time. It is.

[0005]

That is, in the paper feed roller of the present invention, the annular elastic body mounted on the outer peripheral surface of the core body has two layers of an outer layer made of a non-foamed layer and an inner layer made of a foamed layer, or It is characterized by being formed of three layers including an innermost layer made of a non-foamed layer in order to firmly fix the core.

[0006]

FIG. 1 is a cross-sectional view of a paper feed roller of the present invention in which an annular elastic body is formed in two layers.
An annular elastic body composed of two layers, an outer layer 2 made of a non-foamed layer and an inner layer 3 made of a foamed layer, is formed on the outer peripheral surface of the elastic member.
FIG. 2 is a cross-sectional view of the paper feed roller of the present invention in which the annular elastic body is further formed of three layers including an innermost layer made of a non-foamed layer. Outer layer 2,
An annular elastic body composed of three layers of an inner layer 3 made of a foamed layer and an innermost layer 4 made of a non-foamed layer is formed.

In the present invention, the foamed layer and the non-foamed layer constituting the annular elastic body are both layers made of an elastic substance. The hardness of each of the foamed layers is ASKAR-C hardness of 60 degrees or less, particularly 10 to 60 degrees. For the non-foamed layers, the outer layer and the innermost layer have a JIS-A hardness of 50.
Degrees or less, particularly preferably 20 to 50 degrees. ASK of foam layer
If the AR-C hardness exceeds 60 degrees, the displacement with respect to the load becomes small, and a sufficient nip amount cannot be obtained.
If the -A hardness exceeds 50 degrees, the displacement of the non-foamed layer becomes small, the load transmission to the foamed layer becomes insufficient, and a sufficient nip amount cannot be obtained. The foamed layer may be open cells or closed cells, but the size of the cells is 0.2 to 0.6 mm.
Those having φ are preferred. Bubble size is 0.2mmφ
If less than 0.6 mmφ, the hardness of the foam layer does not decrease.
If it exceeds 1, the elasticity and physical properties of the foamed layer are not stable.

The thickness of each layer is 0.3 to 3.0 mm for the outer layer that is a non-foamed layer, 3.5 to 15.0 mm for the inner layer that is a foamed layer, and the innermost layer that is a non-foamed layer. 0.5 to 1.0 mm are each preferred. If the thickness of the outer layer is less than 0.3 mm, the outer layer may disappear due to natural wear, and if it exceeds 3.0 mm, the roller does not have low hardness and at the same time, a large nip amount cannot be secured. If the thickness of the inner layer is less than 3.5 mm, the amount of deformation of the inner layer cannot be secured because the total rubber thickness of the roller is small, and accordingly, a large nip amount cannot be secured. On the other hand, 15.
If it exceeds 0 mm, there is no problem in performance, but there is no performance improvement and it is meaningless, and it is rather disadvantageous economically. When the thickness of the innermost layer is less than 0.5 mm, the innermost layer is absorbed by the inner layer cells, and the fixation to the core body is impaired. When the thickness exceeds 1.0 mm, the outermost layer and the innermost layer are not applied when a load is applied. Then, the inner layer is compressed, and the amount of deformation of the roller becomes narrow. Further, in order to obtain a high friction coefficient, the ratio of the thickness of the inner layer, which is a foamed layer, to the thickness of the outer layer, which is a non-foamed layer, is 3.5 times or more, particularly 3.5 to 6.0.
Preferably, it is doubled. If this ratio is less than 3.5, the inner layer will not be sufficiently deformed by the load applied, and as a result, a sufficient nip amount cannot be secured.

The paper feed roller of the present invention having the above-described structure and configuration has a roller hardness of ASKAR-C hardness of 60 to 60.
By setting it to 40 degrees, a high friction coefficient can be expressed,
In addition, the paper feedability of continuous paper is improved. Further, pressure of normal roller (nip amount), 0.54 cm ² or more in the case of applying a load 100 g, if the applied load 200g is 0.66 cm ² or more, when the applied load 300g 0.7
cm ² or more, but the paper feed roller of the present invention satisfies these conditions, can increase the contact area of the interface between the paper and the roller, can maintain a long contact time, and can achieve stable communication. Paper performance can be demonstrated.

The materials of the inner layer as the foamed layer and the outer and innermost layers as the non-foamed layer may be the same or different. As the material of the outer layer and the non-foamed layer which is the innermost layer,
Although conventionally used vulcanized rubber and thermoplastic elastomer can be used as the material of the paper feed roller, vulcanized rubber is preferable as the material of the outer layer from the viewpoint of abrasion resistance. Hereinafter, the vulcanized rubber and the thermoplastic elastomer will be described.

Examples of the vulcanized rubber include ethylene propylene rubber (EPR), ethylene propylene diene terpolymer rubber (EPDM), natural rubber, isoprene rubber,
General rubbers such as styrene butadiene rubber, polynorbornene rubber, butadiene rubber, nitrile rubber, chloroprene rubber, butyl rubber, halogenated butyl rubber, acrylic rubber, ethylene-vinyl acetate rubber (EVA), urethane rubber, silicone rubber, fluorine rubber, ethylene acrylic rubber , Polyester elastomers, epichlorohydrin rubber, polysulfide rubber, Hypalon (registered trademark), chlorinated polyethylene, and other special rubbers.
Ethylene propylene rubber, ethylene propylene diene terpolymer rubber, natural rubber, isoprene rubber, styrene butadiene rubber, polynorbornene rubber, butadiene rubber, chloroprene rubber, nitrile rubber, butyl rubber, halogenated butyl rubber, acrylic rubber, epichlorohydrin rubber and chlorine Polyethylene rubber is preferred. These vulcanized rubbers can be used alone or as a blend of two or more.

As the thermoplastic elastomer, any one can be selected from, for example, polyolefins, polyurethanes, polyesters, polyamides, polystyrenes and the like. It is particularly preferable to have a portion that easily forms a hard block and a soft block such as an amorphous structure together, and specific examples include the following.

A block copolymer of crystalline polyethylene and an ethylene / butylene-styrene random copolymer obtained by hydrogenating a block copolymer of polybutadiene and a butadiene-styrene random copolymer. Obtained by hydrogenating a block copolymer of polybutadiene and polystyrene, or a block copolymer of polybutadiene or an ethylene-butadiene random copolymer and polystyrene, for example, a diblock copolymer of crystalline polyethylene and polystyrene. Coal, styrene-ethylene / butylene-styrene triblock copolymer, styrene-ethylene / propylene-styrene triblock copolymer, and among others, styrene-ethylene / butylene-styrene block copolymer or styrene-ethylene / propylene -Styrene block copolymer. A block copolymer in which crystalline polyethylene is linked to one or both ends of an ethylene / butylene copolymer.

Among these, particularly, a block copolymer comprising at least one polymer block mainly composed of a vinyl aromatic compound and at least one polymer block mainly composed of a conjugated diene compound is mentioned. Is preferably a hydrogenated block copolymer obtained by hydrogenating a compound having a number average molecular weight of 150,000 to 400,000. These thermoplastic elastomers can be used alone or as a blend of two or more.

If desired, a softening agent can be added to these vulcanized rubbers and thermoplastic elastomers in order to adjust the hardness. The softener is not particularly limited, and is appropriately selected from those conventionally used as plasticizers and plasticizers, for example, various rubber or resin softeners such as mineral oils, vegetable oils, and synthetic oils. be able to. Here, mineral oils include naphthenic and paraffinic process oils, and vegetable oils include castor oil, cottonseed oil, linseed oil, rapeseed oil, soybean oil,
Palm oil, nagiko oil, peanut oil, wood wax, pine oil,
Olive oil and the like. One of these softeners may be used alone, or two or more of them may be used in combination as long as they have good compatibility with each other.

The vulcanized rubber and the thermoplastic elastomer include inorganic additives such as clay, diatomaceous earth, silica, talc, barium sulfate, calcium carbonate, magnesium carbonate, metal oxide, mica, graphite, and aluminum hydroxide. Can improve the tackiness on the surface of the member for office equipment, but silica is more preferable from the viewpoint of reducing the environmental change of the tackiness.

The vulcanized rubber and the thermoplastic elastomer may further contain the following fillers, if necessary. That is, various kinds of metal powder, wood chips, glass powder, ceramic powder, granular or powdered solid filler such as granular or powdered polymer, and other various natural or artificial short fibers and long fibers (eg, straw, hair, glass) Fiber, metal fiber, various other polymer fibers, etc.).

The material of the foamed layer as the inner layer may be polyurethane, polyethylene, polystyrene, or a compounded member obtained by adding a foaming agent to the above-described vulcanized rubber or thermoplastic elastomer as the material of the non-foamed layer.

The material of the core is not particularly limited, and those conventionally used as cores in office equipment members can be used. As this material, for example, AB
Examples thereof include plastics such as S, POM, polycarbonate, and nylon, and metals such as aluminum, SUS, and magnesium alloy, which may be appropriately selected and used depending on the situation. Needless to say, the annular elastic body does not need to be mounted over the entire length of the core,
A plurality of devices of appropriate length may be mounted at appropriate intervals.

[0020]

Next, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples. In addition, various physical properties and characteristics were measured and evaluated according to the following methods.

(1) JIS-A hardness Based on JIS K6253 standard, durometer (A
(Type) Measured using a hardness tester. (2) ASKA-C hardness Measured using an ASKA-C hardness meter manufactured by Kobunshi Keiki Co., Ltd. (3) Friction coefficient Using a friction tester [HEIDON-14 (trade name, manufactured by Shin-Tokyo Kagaku)], paper: XEROX 4024 paper, temperature: 25 ° C, humidity: 60%, roller peripheral speed: 75 mm /
Second, applied load: 100 g, 200 g or 300 g were measured.

(4) Nip Amount to Paper The contact area when the roller was pressed against the glass plate with an applied load of 200 g was measured. (5) Rebound resilience of roller Time Tech Inc. Ball Rebo
The measurement was performed using an und Tester TT502 type. (6) 100,000-sheet passing test Using XEROX 4024 paper cut into strips, the test was performed under a load of 100 g, and evaluated according to the following criteria. : Occurrence rate of paper slip 0%: 0.001% or less
: Over 0.001% and 0.005% or less: 0.0
More than 05% and less than 0.01%: About 70,000 sheets cannot be passed

(7) Adhesion of paper powder This was a visual observation with a microscope, and was evaluated according to the following criteria. ◎: very small ○: small △: slightly large
×: Many (8) Abrasion and Amount of Abrasion of Roller Using a taper abrasion tester, load the sample roller on a table on which AA-1200 sandpaper is set by 100.
g, and the table was rotated 1000 times. Then, the usability was determined and the wear weight was measured with a precision balance.
The abrasion was determined based on the following criteria, and the abrasion amount was the abrasion thickness (mm) of the surface layer calculated from the abrasion weight. ：: uniform natural wear ×: uneven and marked surface roughness

Examples 1 to 6 Non-foamed rubber and foamed rubber A (Examples 1 and 2) or foamed rubber B (Examples 3 to 6) having the composition and properties shown in Table 1
By using the above, a paper feed roller having an annular elastic body formed of an outer layer made of a non-foamed layer and an inner layer made of a foamed layer on the outer peripheral surface of the core was prepared. The thickness and hardness of the outer layer and the inner layer, the coefficient of friction of the paper feed roller, the roller hardness, the nip amount with respect to the paper, and the rebound resilience of the roller were as described in Table 2 as the layer configuration and the roller characteristics. This paper feed roller was subjected to a 100,000 sheet passing test, a paper dust adhesion test, and a roller abrasion test. The results were as described in Table 2 as test results.

COMPARATIVE EXAMPLE 1 A paper feed roller using a non-foamed rubber having the composition and characteristics shown in Table 1 and having an annular elastic body formed of only one non-foamed layer mounted on the outer peripheral surface of the core body It was created. Thickness and hardness of non-foamed layer and coefficient of friction of paper feed roller, roller hardness,
The nip amount with respect to the paper and the rebound resilience of the roller were as described in Table 2 as the layer constitution and the roller characteristics. This paper feed roller was subjected to a 100,000 sheet passing test, a paper dust adhesion test, and a roller abrasion test. The results were as described in Table 2 as the test results. However, the roller hardness was high, the nip amount to the paper was insufficient, the paper passing performance became unstable, and the adhesion of paper dust was somewhat observed. .

Comparative Example 2 Using a foamed rubber A having the composition and characteristics shown in Table 1, a feed roller equipped with an annular elastic body formed of only one foam layer on the outer peripheral surface of a core was used. Created. The thickness and hardness of the foam layer, the coefficient of friction of the paper feed roller, the roller hardness, the nip amount with respect to the paper, and the rebound resilience of the roller were as described in Table 2 as the layer configuration and the roller characteristics. This paper feed roller was subjected to a 100,000 sheet passing test, a paper dust adhesion test, and a roller abrasion test. The results were as described in Table 2 as test results. However, the roller hardness was too low, paper jams occurred, and a large amount of paper dust adhered, reducing the frictional force. It could not withstand the paper test.

[0027]

[Table 1]

[0028]

[Table 2]

[0029]

[Table 3]

[0030]

The paper feed roller of the present invention has a high rebound resilience against paper, a large amount of pressure contact, a high abrasion resistance, and a friction coefficient, and can exhibit stable paper passing performance for a long period of time.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a paper feed roller of the present invention in which an annular elastic body is formed of two layers, an outer layer made of a non-foamed layer and an inner layer made of a foamed layer.

FIG. 2 is a paper feed roller according to the present invention in which an annular elastic body is formed of three layers in which an outer layer made of a non-foamed layer and an inner layer made of a foamed layer are further added to an innermost layer made of a non-foamed layer; FIG.

[Explanation of symbols]

 1: Core 1 2: Outer layer made of non-foamed layer 3: Inner layer made of foamed layer 4: Innermost layer made of non-foamed layer

Claims (7)

[Claims] 1. A paper feed roller having an annular elastic body attached to an outer peripheral surface of a core body, wherein the annular elastic body is formed of two layers, an outer layer made of a non-foamed layer and an inner layer made of a foamed layer. A paper feed roller, characterized in that: 2. A paper feed roller having an annular elastic body attached to an outer peripheral surface of a core body, wherein the annular elastic body is an outer layer made of a non-foamed layer, an inner layer made of a foamed layer, and an innermost layer made of a non-foamed layer. A sheet feed roller formed of three layers: 3. The outer layer has a thickness of 0.3 to 3.0 mm, and the inner layer has a thickness of 3.5 to 15.0 mm.
The paper feed roller according to 1. 4. The outer layer has a thickness of 0.3 to 3.0 mm, the inner layer has a thickness of 3.5 to 15.0 mm, and the innermost layer has a thickness of 0.5 to 1.0 mm. The sheet feed roller according to claim 2. 5. The paper feed roller according to claim 1, wherein the outer layer has a JIS-A hardness of 60 degrees or less, and the inner layer has an ASKA-C hardness of 50 degrees or less. 6. The outer layer and the innermost layer have a JIS-A hardness of 60.
The sheet feeding roller according to claim 2, wherein the inner layer has an ASKA-C hardness of 50 degrees or less. 7. The ratio of the thickness of the inner layer to the thickness of the outer layer,
The paper feed roller according to claim 3, wherein the ratio is 3.5 times or more.