JPH0858999A - Paper feed roll and paper feeder - Google Patents

Abstract

PURPOSE: To provide a paper feed roll performing a reliable paper feed without contaminating the appearance for a long period and without contaminating paper, by comprising a rubber composition containing a low molecular material holding medium material compound and a rubber material, and forming a groove mountain, with a section formed in asymmetrical waveform shape, at a right angle in a paper feed direction in the peripheral surface. CONSTITUTION: A paper feed roll is composed of a rubber composition 5, and a low molecular material of constituting the rubber composition 5, having 5×10<5> centipoise or less viscosity at 100 deg.C and 20000 or less mean molecular weight, is in a liquid state preferable at a room temperature. Both the low molecular material and medium material are selected so as to obtain 3.0 or less each solubility parameter value, and a difference of the solubility parameter value between the low molecular material and a rubber material is prevented from exceeding 4.0. A compounded amount in the rubber material of a low molecular material holding medium material compound is preferably 10 to 300 pts.wt. It is preferable that, in the paper feed roll, a space L of a groove mountain 6 is 0.05mm<=L<=1.0mm, a horizontal distance 1 from a groove bottom to a mountain top is -0.05<=1/L<=0.5, and height(t) of the groove mountain 6 is 0.02<=t/L<=0.5.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a paper feed roll using friction and a paper feed device using this roll, and more particularly to a paper feed device for office automation equipment such as copiers, laser printers and facsimiles. The present invention relates to a paper feed roll and a paper feed device that have excellent stain resistance and paper feed characteristics for used paper.

[0002]

2. Description of the Related Art Conventionally, as a paper feeding device mounted on a copying machine, a printer or the like, a paper feeding mechanism utilizing the friction of a rubber roll has been used. FIG. 7 shows an example of such a device. A pickup roll (paper feed roll) 2 is provided in a pressure-contact state on the paper 1 stacked on the paper tray, and the pickup roll (paper feed roll) 2 rotates to send out the paper 1 and subsequently installed. When the paper 1 is further fed by the feed roll (paper feed roll) 3 and the paper 1 is double-fed, the reverse roll (paper feed roll) 4 rotates in the counter paper feed direction and It has a mechanism to stop the paper. The paper feed rolls 2 to 4 mounted on the paper feed mechanism are provided with a rubber material which is filled with a large amount of oil to obtain a high friction coefficient and has a low hardness, and the outer peripheral surface of the roll is polished. The surface is roughened and the high friction coefficient is expressed to ensure reliable paper feeding.

[0003]

However, in the paper feed roll having the rubber material containing a large amount of oil as described above, oil migration occurs, causing problems in product performance, appearance, and paper contamination. . Further, as described above, it is well known that a high friction coefficient can be obtained by roughening the outer peripheral surface of the roll by polishing, however, what kind of polishing is performed will produce a high friction coefficient and stably. It has not been suggested if it can be done. Therefore, although a paper feed roll having a high initial friction coefficient has been obtained by polishing, a paper feed roll having a stable friction coefficient even during long-term use has not been obtained.

The present invention has been made in view of the above circumstances, and does not cause appearance contamination or paper contamination even during long-term use, and realizes reliable paper feeding by expressing a stable friction coefficient. An object of the present invention is to provide a roll and a paper feeding device equipped with the paper feeding roll.

[0005]

In order to achieve the above-mentioned object, the paper feed roll of the present invention is a paper feed roll that uses friction to feed a low molecular weight material containing a low molecular weight material and a medium material. Made of a rubber composition containing the material-holding medium material composite (A) and the rubber material (B), and the low molecular weight material is 5 × 1 at 100 ° C.
0 ⁵ centipoise has a viscosity of less, with the difference between the respective solubility parameter values of the low molecular weight material and the medium material is 3.0 or less, and the weight ratio of both wood is 1.0 or more, a low molecular material The difference in the solubility parameter value of each rubber material (B) is 4.0 or less, and the groove ridges having an asymmetric corrugated cross-section are formed on the outer peripheral surface at right angles to the paper feeding direction. L), the horizontal distance from the groove bottom to the summit is l,
Assuming that the height of the groove is t, 0.02 ≦ t / L ≦ 0.5,
-0.05 ≦ l / L ≦ 0.5, 0.05 mm ≦ L ≦ 1.0
It is formed to have a size of mm. Further, this paper feeding device uses such a paper feeding roll.

[0006]

In the present invention, the low hardness rubber material distributed to the paper feed roll is a rubber composition in which the low molecular weight material-holding medium composite (A) is mixed with the rubber material (B). The hardness of the composition can be easily designed and controlled, and the low molecular weight material that plays the role of lowering the hardness is dispersed in the rubber material (B) as the composite (A) held in the medium material. Very few bleeds. Therefore, the obtained paper roll has very little appearance contamination and paper contamination. In addition, since the paper feed roll (rubber) is surely worn due to friction, the state of the contact surface (friction surface) changes between the initial use and the elapsed time, and the friction coefficient developed there is also dependent on the progress of wear. It will change. Therefore, even if a contact surface that exhibits a high friction coefficient is formed by polishing, the high friction coefficient is only manifested at the initial stage, and the state (shape) of the contact surface changes over the course of use, and the friction coefficient that develops also changes. (Usually decreases). This is because the phenomenon of wear is extremely complicated and it is extremely difficult to predict the state (shape) of the contact surface newly formed on the contact surface due to wear during use. When rubber is brought into frictional contact with a rigid body (including paper), the first microcracks occur on the rubber surface, and the microcracks spread over the entire worn surface of the rubber.
The generated microcracks grow rapidly and form a steady abrasion pattern. In this way, the abrasion pattern, which is a periodic wavy pattern, determines the initial friction surface shape under constant friction conditions (usage conditions) because the periodic pitch interval and depth are determined by the friction conditions. However, eventually, the abrasion pattern shape is determined by this friction condition. In other words, the initial friction coefficient is expressed by the initial friction surface shape,
When a new abrasion pattern is formed as the wear progresses, the friction coefficient developed here depends on the formed abrasion pattern and changes from the initial friction coefficient. Therefore, if the abrasion pattern shape that is formed during use is given to the friction surface in advance, the same friction surface shape can be maintained at any stage from the beginning of use to the end of use and the end of use. Can be expressed. The abrasion pattern shape formed during use is determined by the abrasion resistance of the rubber material forming the paper feed roll and the size of the load applied to the roll during use, and the friction pattern is used in the paper feed mechanism based on the paper feed mechanism. Under the conditions of use, an abrasion pattern is formed within the shape and dimensions described above.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Paper feed roll 5 according to a preferred embodiment of the present invention.
1 is made of a rubber composition 5, and as shown in FIG. 1, groove grooves 6 having an asymmetrical corrugated cross section are formed on the outer peripheral surface (contact friction surface) at right angles to the sheet feeding direction. This paper feed roll is composed of a rubber composition 5 containing a low molecular weight material-holding medium material composite (A) containing a low molecular weight material and a medium material, and a rubber material (B).

The low molecular weight material has a viscosity at 100 ° C. of 5 × 10 ⁵ centipoise or less, preferably 1 × 10 ⁵
It is a material of centipoise or less. From the viewpoint of the molecular weight, the number average molecular weight of the low molecular weight material is 20,000 or less, preferably 10,000 or less, more preferably 5,000.
It is the following. Usually, a liquid or liquid material at room temperature is preferably used. Also, hydrophilic or hydrophobic low molecular weight materials can be used. As the low molecular weight material, any material can be used as long as it satisfies such a condition, and there is no particular limitation, but examples thereof include the following materials. Softener: Mineral oil-based, vegetable oil-based, synthetic-based softener for various rubbers or resins. Examples of mineral oil-based oils include process oils such as aromatic oils, naphthene oils, and paraffin oils. Vegetable oils include castor oil, cottonseed oil, linseed oil, rapeseed oil, soybean oil, palm oil, coconut oil,
Examples include peanut oil, wood wax, pine oil and olive oil. Plasticizer: Phthalates, phthalic acid mixed group esters, aliphatic dibasic acid esters, glycol esters, fatty acid esters, phosphoric acid esters, stearic acid esters, and other ester plasticizers, epoxy plasticizers, plastics for other plastics Agents or phthalate-based, adipate-based, separate-based, phosphate-based, polyether-based, polyester-based plasticizers for NBR. Tackifiers: various tackifiers such as coumarone resin, coumarone-indene resin, phenol terpene resin, petroleum hydrocarbon, rosin derivative, etc. Oligomer: Crown ether, fluorinated oligomer, polyisobutylene, xylene resin, chlorinated rubber, polyethylene wax, petroleum resin, rosin ester rubber, polyalkylene glycol diacrylate, liquid rubber (polybutadiene, styrene-butadiene rubber, butadiene-acrylonitrile rubber, poly Various oligomers such as chloroprene), silicone-based oligomers, and poly-α-olefins. Lubricants: Hydrocarbon lubricants such as paraffin and wax, fatty acid lubricants such as higher aliphatic compounds and oxyfatty acids, fatty acid amide lubricants such as fatty acid amides and alkylenebisfatty acid amides, fatty acid lower alcohol esters, fatty acid polyhydric alcohol esters, fatty acids Ester-based lubricants such as polyglycol ester, alcohol-based lubricants such as fatty alcohol, polyhydric alcohol, polyglycol and polyglycerol, metal soaps, mixed lubricants.

In addition, latex, emulsion, liquid crystal, bituminous composition, clay, natural starch, sugar, inorganic silicone oil, phosphazene and the like are also suitable as the low molecular weight material. In addition, animal oils such as cow oil, pig oil, horse oil,
Bird oil or fish oil: honey, fruit juice, or dairy products such as chocolate, yogurt, hydrocarbon, halogenated hydrocarbon, alcohol, phenol, ether, acetal, ketone, fatty acid, ester,
Organic solvents such as nitrogen compounds and sulfur compounds: Or various medicinal components, soil modifiers, fertilizers, petroleum,
Water and aqueous solutions are suitable. These components may be used alone or in combination of two or more.

The low molecular weight material is optimum in consideration of the required characteristics and uses of the rubber composition 5, the compatibility with the medium material and the rubber material (B) which are other components of the paper feed roll according to the present invention, and the like. Selected and used in optimal amounts.

The above-mentioned medium material is a material having a function as a medium of the low molecular weight material and the rubber material (B), and more specifically, a uniform composition of a large amount of the low molecular weight material and the rubber material (B). In order to make it possible to use a large amount of low molecular weight material and medium material,
A low molecular weight material-holding medium composite (A) holding a large amount of a low molecular weight material is first obtained, and a rubber composition 5 which holds a desired large amount of a low molecular weight material in combination with the rubber material (B). Is what you are trying to get. Even if the low molecular weight material, the medium material and the rubber material (B) are mixed at the same time, a uniform and low hardness rubber composition 5 cannot be obtained. Further, even if a large amount of low molecular weight material and the rubber material (B) are directly mixed and an attempt is made to obtain a rubber material (B) containing a large amount of low molecular weight material, the low molecular weight material cannot be mixed uniformly and bleeding occurs. It often happens that the rubber composition 5 does not have the desired low hardness. Here, "holding" the low molecular weight material means that the low molecular weight material uniformly disperses the medium material and the rubber material (B) and does not bleed, or bleeding is suppressed. Of course,
Depending on the purpose of the rubber composition 5, the degree of bleeding can be easily controlled. Finally,
This low molecular weight material-holding medium composite (A) is a rubber material (B).
It is not clear that the uniform mechanism of uniform dispersion in the compound (A) when mixed with is that most of the composite (A) is retained in the rubber material (B) in the state of being divided into fine particles. Conceivable.

As the medium material, any material can be used as long as it has a function as described above and forms the composite (A) which holds a large amount of low molecular weight material, but it is usually high in thermoplasticity. A molecular material or various materials having the polymeric material as a constituent element is used.

Examples of the medium material include styrene type (butadiene styrene type, isoprene styrene type, etc.), vinyl chloride type, olefin type (butadiene type, isoprene type,
Ethylene propylene type, etc.), ester type, amide type, urethane type, and other thermoplastic elastomers, and their hydrogenated and other modified products, styrene type, ABS type,
Olefin type (ethylene type, propylene type, ethylene propylene type, ethylene styrene type, propylene styrene type, etc.), vinyl chloride type, acrylic acid ester type (methyl acrylate type, etc.), methacrylic acid ester type (methyl methacrylate type, etc.) , Carbonate type, acetal type, nylon type, halogenated polyether type (chlorinated polyether type, etc.), halogenated olefin type (tetrafluoroethylene type, fluorinated-ethylene chloride type, fluorinated ethylene propylene type, etc.), cellulose Examples thereof include thermoplastic resins of types (acetyl cellulose type, ethyl cellulose type, etc.), vinylidene type, vinyl butyral type, alkylene oxide type (propylene oxide type, etc.), and rubber modified products of these resins.

As a concrete thermoplastic polymer material, it is particularly preferable to use a material having a portion which easily forms a hard block such as a crystal structure or an agglomerate structure and a soft block such as an amorphous structure, among them. Specifically, the following are mentioned.

A block copolymer of polyethylene and an ethylene / butylene-styrene random copolymer obtained by hydrogenating a block copolymer of polybutadiene and a butadiene-styrene random copolymer. A block copolymer of polybutadiene and polystyrene, or a block copolymer of polyethylene / butylene and polystyrene obtained by hydrogenating a block copolymer of polybutadiene or an ethylene-butadiene random copolymer and polystyrene. Ethylene-propylene rubber. Of these, a block copolymer of polyethylene and an ethylene-styrene random copolymer is particularly preferable.

The low molecular weight material, the medium material, and the low molecular weight material-holding medium material composite (A) are partially described in JP-A-5-239256 and JP-A-5-194763. The medium material having the three-dimensional continuous network skeleton structure disclosed in this publication is also suitably used as a typical one in the present invention.

The medium material is not particularly limited, but can be used in a usual bulk form, granular form, gel form, foam form, non-woven fabric form or the like. It can also be used in a form in which a capsule containing a low molecular weight material is incorporated.

In obtaining the low molecular weight material-holding medium material composite (A) containing a large amount of low molecular weight material and medium material, the difference in solubility parameter value between the low molecular weight material and the medium material used is 3.0. Both materials are selected so as to be preferably 2.5 or less. If the difference exceeds 3.0, it is difficult to hold a large amount of the low molecular weight material from the viewpoint of compatibility, which is an obstacle to lowering the hardness of the rubber composition 5, and bleeding of the low molecular weight material tends to occur, which is preferable. Absent.

Further, the weight ratio of the low molecular weight material to the medium material is 1.
It is 0 or more, preferably 2.0 or more, and more preferably 3.0 or more. If this weight ratio is less than 1.0, it becomes difficult to obtain the rubber composition 5 having low hardness.

As the method for producing the composite (A) containing the low molecular weight material and the medium material, an optimum method including a known method may be used depending on the types, characteristics, mixing ratios of the low molecular weight material and the medium material,
There is no particular limitation. The method described in the above-mentioned Japanese Patent Laid-Open No. 5-239256 is also one method.

The rubber material (B) used for the paper feed roll is ethylene propylene rubber (EP) in view of environmental conditions and required performance used as a paper feed roll mounted in the paper feed device.
R, EPDM), butyl rubber, natural rubber (NR), isoprene rubber (IR), styrene butadiene rubber (SB
R), butadiene rubber (BR), nitrile rubber (NB
R), chloroprene rubber (CR), silicone rubber, urethane rubber (UR) and the like can be used alone or in a blend.

In the paper feed roll according to the present invention, the difference in solubility parameter value between the low molecular weight material and the rubber material (B) is 4.0 or less, preferably 3.0 or less.
Both materials are selected. The low molecular weight material is mixed with the rubber material (B) in the form of the low molecular weight material-holding medium composite (A), but in this case also, the compatibility between the low molecular weight material and the rubber material (B) becomes a problem. When the difference in this parameter exceeds 4.0, the low molecular weight material retained in a large amount in the composite (A) is hard to be retained in the rubber material (B) from the viewpoint of compatibility, and the hardness of the rubber composition 5 is reduced. Of the low molecular weight material is liable to occur, which is not preferable.

The mixing method of the low molecular weight material-holding medium composite (A) and the rubber material (B) is not limited, but an optimum method including a known method may be adopted depending on the characteristics of both and the mixing ratio. . Thereby, the rubber composition 5 of the paper feed roll according to the present invention can be easily obtained.

The rubber composition 5 can be controlled to have a desired hardness in the low hardness region. For example, measurement temperature 2
With Asker C hardness at 5 ° C., an ultra-hardness of 10 or less can be easily achieved.

The rubber composition 5 contains a vulcanizing agent (sulfur, peroxide, etc.), a vulcanizing accelerator (tetramethylthiuram monosulfide (Noccer TS), mercaptobenzothiazole (Noccer M), N-cyclohexyl-2-benzothiazyl). Sulfenamide (Noccellar CZ), diphenylguanidine (Noccellar G), etc., vulcanization aid (ethylene glycol dimethacrylate (EDMA), triallyl isocyanurate (TAIC), N, N'-m-phenylenedimaleimide (Varnock) PM)), various fillers (carbon black, white carbon, white luster C
C, etc.), an antiaging agent (styrenated phenol (Antage SP-P), 2,6 di-charbutyl-4-methylphenol (Nocrac 200), dibutyl hydrogen phosphite (DBP), etc.) And antistatic agent (conductive carbon (Ketjen Black E
C), white conductive powder, etc.) and vulcanized to obtain a paper feed roll mounted in the paper feeder of the present invention.

The rubber composition 5 may further contain the following fillers, if necessary. That is, clay,
Diatomaceous earth, talc, barium sulfate, calcium carbonate, magnesium carbonate, metal oxide, mica, graphite,
Scale-like inorganic filler such as aluminum hydroxide, various metal powder, wood chips, glass powder, ceramic powder, granular or powder solid filler such as granular or powder polymer, and other various natural or artificial short fibers, long fibers ( For example, straws, bristles, glass fibers, metal fibers, other various polymer fibers, etc.) can be blended.

In the rubber composition 5, the compounding amount of the low molecular weight material-holding medium composite (A) containing the low molecular weight material and the filler in the rubber material (B) is such that the workability and the loss at the time of manufacturing the paper feed roll are low. From the viewpoint of characteristics, it is 400 parts by weight or less, preferably 10 to 300 parts by weight, and more preferably 20 to 2 parts by weight based on 100 parts by weight of the rubber material.
It is 00 parts by weight. If it is 10 parts by weight or less, the effect of lowering the hardness of the rubber composition becomes poor, while if it is 400 parts by weight or more, creep and permanent set (set) of the paper feed roll increase.

The JIS-A hardness of the paper feed roll according to the present invention is 60 ° or less, preferably 50 ° or less, more preferably 40 ° or less, most preferably 30 ° or less, and mounted on a paper feeding device. It can be designed and controlled within the range suitable for the paper feed roll used.

FIGS. 2 to 5 show various modifications of the groove crest 6. The groove crest 6 has a crest 7 and a groove bottom 8, and the interval between the crests 6 (the length of the crest bottom). Is L, the horizontal distance from the groove bottom 8 to the crest 7 is l, and the height of the groove crest 6 is t. The abrasion pattern formed by the abrasion of the rubber (paper feed roll) and the rigid body (including the paper) due to the repeated abrasion has the cross-sectional shape shown in FIGS. In FIG. 2, the rotation direction is the direction of the arrow, and the rotation is from right to left in FIGS. However, rotation in the opposite direction is also acceptable.

The interval L between the groove crests 6, the horizontal distance 1 from the groove bottom 8 to the crest 7 and the height t of the groove crests 6 are optimum depending on the wear resistance of the paper feed roll and the usage conditions of the paper feed roll. Although different, under the condition that the paper feed roll composed of the rubber composition 5 according to the present invention is used in the paper feeding device according to the present invention,
The distance L between the groove crests 6 is 0.05 mm ≦ L ≦ 1.0 mm, and the horizontal distance 1 from the groove bottom 8 to the crest 7 is −0.05 ≦ l / L ≦
0.5, the height t of the groove 6 is preferably 0.02 ≦ t / L ≦ 0.5, more preferably 0.05 mm ≦ L ≦ 0.5.
mm, -0.05≤l / L≤0.3, 0.02≤t / L≤
0.5, more preferably 0.05 mm ≦ L ≦ 0.3 mm, 0
≦ l / L ≦ 0.2, 0.05 ≦ t / L ≦ 0.3,
Optimally, 0.05 mm ≦ L ≦ 0.2 mm, 0 ≦ l / L ≦ 0.
1, 0.1 ≦ t / L ≦ 0.3.

Next, the sheet feeder of the present invention will be described. As in the conventional case, as shown in FIG. 7, the pickup roll 2 is placed on the sheet 1 stacked in the sheet tray or the sheet cassette.
Is provided in a pressure contact state, and the pickup roll 2 rotates to feed the sheet 1, and then the feed roll 3 installed further feeds the sheet 1. When the sheet 1 is double-fed, the sheet is fed to the feed roll 3. The reverse roll 4 provided so as to sandwich the paper path rotates in the direction opposite to the paper feed direction to stop the paper under the multi-fed paper. At least one or two or more of the pickup roll 2, the feed roll 3, and the reverse roll 4 used are the paper feed rolls made of the rubber composition 5 described above.

Next, the paper feeding performance of the paper feeding apparatus of the present invention in which a paper feeding roll having the shape of the groove 6 as shown in FIG. , The coefficient of friction stability was tested, and the results are shown in comparison with the same test results conducted on a conventional paper feeding device equipped with a conventional roll whose outer peripheral surface was polished using a conventional rubber material. Shown in 1.

[0033]

[Table 1]

In Example 1 in Table 1, 100 parts by weight of rubber EPDM (Nordel 1040 manufactured by DuPont) and paraffin oil of low molecular weight material (Sunpar 150 manufactured by Nippon San Oil Co., Ltd.) are used.
80 parts by weight of a medium material / hydrogenated SBR (a block copolymer composed of polyethylene and an ethylene-styrene random copolymer obtained by hydrogenating a block copolymer composed of a butadiene-styrene random copolymer and polybutadiene) ) A rubber composition prepared by Brabender mixing as a composite (low molecular weight material-holding medium composite) held in 20 parts by weight is put into a predetermined mold and vulcanized and cured at 160 ° C. for 30 minutes, A paper feed roll having a predetermined groove on the outer circumference of the roll was manufactured.

In Example 2 in Table 1, the rubber composition prepared in the same manner as in Example 1 was put into a predetermined mold, vulcanized and cured, and then predetermined grooves were added by polishing. A paper feed roll was manufactured.

In Comparative Example 1 in Table 1, vulcanization and curing were performed in the same manner as in Example 2, and then conventional polishing was applied to the surface to manufacture a paper feed roll. In Comparative Example 2, in Example 1, 2. Instead of the low molecular weight material-holding medium composite of Comparative Example 1, low molecular weight paraffin oil (Sunpar 150, manufactured by Nippon San Oil Co., Ltd.) 80
A rubber composition prepared by mixing parts by weight with a Brabender was put into a predetermined mold, vulcanized and cured, and then a conventional polishing process was applied to the surface to manufacture a paper feed roll. Further, in Comparative Example 3, after the rubber composition prepared in the same manner as in Comparative Example 2 was put into a predetermined mold and vulcanized and cured, the surface was not subjected to any processing, and a so-called surface-smooth paper feed roll was used. Was manufactured.

The characteristics compared in Table 1 are based on the following tests. (1) Hardness: 25 × 25 × prepared under the same conditions as each roll
JIS K for a block sample of 15 ^t (mm)
It was measured by a hardness test (type A) specified by 6301. (2) Contamination: 30φ x 1 produced under the same conditions as each roll
Place a plain paper for copiers on the upper and lower surfaces of a 2.5 ^t (mm) columnar sample and sandwich it between two iron plates with a 9.5 mm spacer at 25% compression, and place it in an atmosphere at 70 ° C. After standing for 22 hours, the stain on the plain paper surface and the stain on the appearance of the sample were visually confirmed. (3) Coefficient of friction: As shown in FIG. 6, each roll was mounted on a frictional force measuring device with mounting bolts 9, and a linear velocity of 400 was applied to the fixed plain paper 10 with a load of 500 gf.
The frictional force generated while rotating at a peripheral speed of mm / sec was measured with a load cell.

The first embodiment uses a paper feed roll manufactured by die transfer, and the second embodiment uses a polishing roll to form grooves on the surface of the roll having an asymmetrical corrugated shape. As the shape, the asymmetrical corrugated shape given to the roll and the shape of the roll surface based on the abrasion pattern shape formed by the abrasion of the roll after 100,000 sheets have passed are matched. From 5,000 sheets to the end of the sheet (100,000 sheets)
The coefficient of friction was stable in the process of sheet passing, and paper was not jammed and good sheet passing was possible.

Comparative Examples 1 and 2 are obtained by roughening the roll surface by conventional polishing which is applied to the roll surface for the purpose of increasing the initial friction coefficient without considering the shape of the abrasion pattern formed after passing the paper. The initial surface morphology formed at that time has a shape similar to a predetermined groove ridge whose cross section has an asymmetrical wavy shape, but the abrasion pattern shape formed by the abrasion of the roll after 100,000 sheets have passed is: Since the roll surface morphology is different, the friction coefficient decreases as the paper passes, and finally stabilizes after 100,000 sheets of paper having a predetermined roll surface morphology.

Comparative Example 3 is the result of a test using a paper feed roll in a so-called surface slippery state in which no processing is performed on the roll surface. The initial friction coefficient is very high due to the high smoothness of the roll surface, but friction decreases as the paper passes, and a roll surface morphology based on the abrasion pattern that matches the paper passing conditions (wear conditions) is almost formed. 1
After 10,000 sheets, the coefficient of friction is expressed by the surface morphology.

As is clear from the results shown in Table 1, a rubber composition obtained by mixing the low molecular weight material-holding medium composite with a rubber material was distributed, and a large number of groove ridges having a predetermined shape were formed on the outer peripheral surface of the roll. The paper feed roll according to the present invention is stable and has a high friction coefficient, excellent paper feed characteristics, and has no appearance contamination or paper contamination. It is recognized that the paper device is a paper feeding device having excellent paper feeding and paper feeding characteristics.

[0042]

As described above in detail, according to the paper feed roll of the present invention, there is no paper contamination or appearance problem even when it is used for a long period of time, and the roll surface is formed by abrasion of rubber during use of the roll. Predetermined grooves that have an asymmetrical corrugated cross-section similar to the abrasion pattern are formed at a right angle to the paper feeding direction, so that the contact surface condition is constant throughout the initial period of use, after use, and at the end of use. Provided is a paper feed roll capable of stable friction coefficient and stable paper feed. According to the paper feed device of the present invention equipped with this paper feed roll, stable paper feed such as paper jam is prevented for a long period of time. Can be done by The paper feed roll and the paper feed device of the present invention can be effectively used as a paper feed roll and a paper feed device of OA equipment such as a copying machine and a printer, and any device having a paper feed mechanism.

[Brief description of drawings]

FIG. 1 is a perspective view of a paper feed roll of the present invention.

FIG. 2 is a partially enlarged view of a paper feed roll.

FIG. 3 is a partially enlarged view showing another example of the paper feed roll.

FIG. 4 is a partially enlarged view showing another example of the paper feed roll.

FIG. 5 is a partially enlarged view showing still another example of the paper feed roll.

FIG. 6 is a diagram illustrating a method of measuring a friction coefficient.

FIG. 7 is a schematic view of a conventional paper feeding device.

[Explanation of symbols]

 1 Paper 2, 3, 4 Paper Feed Roll 5 Rubber Composition 6 Groove Mountain 7 Mountain Top 8 Groove Bottom

Claims (4)

[Claims] 1. A paper feed roll that uses friction to feed a rubber composition containing a low molecular weight material-holding medium material composite (A) containing a low molecular weight material and a medium material and a rubber material (B). The low molecular weight material has a viscosity of 5 × 10 ⁵ centipoise or less at 100 ° C., the difference in solubility parameter value between the low molecular weight material and the medium material is 3.0 or less, and the weight of both materials is high. The ratio is 1.0 or more, the difference in solubility parameter value between the low molecular weight material and the rubber material (B) is 4.0 or less, and the outer peripheral surface has a groove with an asymmetrical cross section in the feeding direction. 0.02 ≦ t / L ≦, where L is the distance between the crests (length of the crest bottom), l is the horizontal distance from the crest to the crest, and t is the height of the crests. 0.5 −0.05 ≦ l / L ≦ 0.5 0.05 mm ≦ L ≦ 1.0 mm Paper feed roll to collect. 2. A groove formed in a cross-section having an asymmetrical wavy shape is provided by a method of transferring a shape which is previously applied to a mold.
Paper feed roll described. 3. The paper feed roll according to claim 1, wherein the groove ridges whose cross section has an asymmetrical wavy shape are provided by surface polishing. 4. A sheet feeding device provided with a plurality of sheet feeding rolls for feeding a sheet by friction, wherein at least one of the plurality of sheet feeding rolls is used.
A sheet feeding device according to any one of items 1 to 5.