JPH08188271A - Paper feeding roller and paper feeding device - Google Patents

Abstract

PURPOSE: To prevent the occurrence of deviated wear by a method wherein a number of grooves for damping wear and a number of groove crests in an asymmetrical waveform shape in cross section to hold a conveyance force are formed in an outer peripheral surface, making contact with a paper sheet, at right angles with a paper conveyance direction and the sizes of the groove and the groove crest are specified. CONSTITUTION: A paper feed roller is formed of a low molecular material having viscosity of 5×10<5> centipoise or less at 100 deg.C, a difference in a solubility parameter value between the low molecular material and a medium material being 3.0 or less, a weight ratio between the two materials being 1.0 or more, a difference in a solubility parameter value between the low molecular material and a rubber material being 4.0 or less, and a weight ratio of 0.3 or more. A number of grooves 6 formed in the outer peripheral surface of the roller satisfy formulas of 0.1mm<=W<=2mm, and 0.5<=H<=2mm, and 1mm<=L<=20mm, wherein width is W, depth is H, and a distance L. A number of asymmetrical waveform groove crests 7 satisfy formulas of 0.05mm<=P<=2mm, -0.05mm<=1<=0.5, and 0.2mm<=t<=0.5mm. wherein a distance is P, a horizontal distance between a groove bottom 9 and a crest 8, and height is (t). This constitution performs the reliable feed of paper sheets.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a paper feed roller using friction and a paper feed device using this roller, 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 feeding roller and a paper feeding device that have excellent stain resistance and paper feeding 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 friction of a rubber roller has been used. FIG. 16 shows an example of such a device. A pickup roller (paper feed roller) 2 is provided in a pressure contact state on the paper 1 stacked on the paper tray, and the pickup roller (paper feed roller) 2 is rotated to send out the paper 1 and subsequently installed. When the paper 1 is further fed by the feed roller (paper feed roller) 3 and the paper 1 is double-fed, the reverse roller (paper feed roller) 4 rotates in the direction opposite to the paper feed direction and It has a mechanism to stop the paper. The paper feed rollers 2 to 4 mounted on the paper feed mechanism are provided with a rubber material containing a large amount of oil to achieve a high friction coefficient and having a low hardness, and the outer peripheral surface of the roller is polished. The surface is roughened and the high friction coefficient is expressed to ensure reliable paper feeding.

[0003]

However, in the paper feed roller provided with 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 roller by polishing, however, what kind of polishing is performed, a high friction coefficient and stable expression are obtained. It has not been suggested if it can be done. Therefore, although a paper feed roller having a high initial friction coefficient has been obtained by polishing, a paper feed roller having a stable friction coefficient even during long-term use has not been obtained.

In the case of a combination of a paper feed roller (feed roller, reverse roller, pickup roller) whose outer peripheral surface is roughened by polishing as described above, abrasion of the roller occurs due to the roller being rubbed against the paper during use. In addition, the paper friction may change the friction coefficient of the roller to reduce the paper conveyance force, and abnormal slippage may cause local wear (uneven wear) of the roller to make the paper conveyance impossible.

The present invention has been made in view of the above circumstances, and does not cause appearance stains or paper stains even during long-term use and does not cause uneven wear, and has excellent abrasion resistance and stable friction. An object of the present invention is to provide a paper feed roller that can reliably feed paper by expressing a coefficient, and a paper feed device equipped with the paper feed roller.

[0006]

In order to achieve the above object, in the paper feed roller of the present invention, the roller outer peripheral surface layer contains a low molecular weight material-containing medium material composite (A). ) And a rubber material (B), the low molecular weight material has a viscosity of 5 × 10 ⁵ centipoise or less at 100 ° C., and the difference in solubility parameter value between the low molecular weight material and the medium material is In addition to 3.0 or less, the weight ratio of both materials is 1.0 or more, and the difference in solubility parameter value between the low molecular weight material and the rubber material (B) is 4.0 or less. And the rubber material has a weight ratio of 0.3 or more, and the medium material is a hydrogenated product of a butadiene polymer or a butadiene-styrene copolymer having a three-dimensional continuous network skeleton structure, Rubber material is ethylene propylene rubber, ethylene propylene Polyene terpolymer rubber, natural rubber, isoprene rubber, styrene butadiene rubber, butadiene rubber, polynorbornene rubber or blended rubbers of them, with a large number of grooves for abrasion reduction on the outer peripheral surface in contact with paper and retention of conveying force A plurality of groove ridges having an asymmetrical corrugated cross section are formed at right angles to the paper transport direction, and the plurality of grooves formed on the outer peripheral surface have a width W, a depth H, and a groove. If the distance is L, and a large number of groove ridges having an asymmetrical corrugated cross section, the distance between the groove ridges is P, the horizontal distance from the groove bottom to the peak is l, and the height of the groove ridge is t, 0.1 mm ≤ W≤2mm 0.5mm≤H≤2mm 1mm≤L≤20mm and 0.05mm≤P≤2mm -0.05≤l / P≤0.5 0.02mm≤t≤0.5mm It was done. Further, this paper feeding device uses such a paper feeding roller.

[0007]

In the present invention, the low hardness rubber material distributed to the paper feed roller 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 feed roller has very little appearance contamination and paper contamination.

When an elastic body and a rigid body (including paper) are brought into frictional contact with each other, stick-slip vibration having a frequency of the order of 10 Hz on the surface of the elastic body and high-frequency micro-vibration (500 to 1000H) induced by the stick-slip vibration are generated.
z order) occurs. This high-frequency micro-vibration causes the first microcracks on the surface of the elastic body, and the microcracks spread over the entire wear surface of the elastic body. The generated microcracks grow rapidly due to stick-slip vibration and become a steady abrasion pattern. It is a periodic external force, that is, two types of vibrations peculiar to the elastic body, which are generated when the elastic body and the rigid body make frictional contact, to generate and grow the aprasion pattern which is a periodic pattern in this way. These vibrations become surface waves and cover the entire contact surface of the elastic body. Since such a surface wave can be attenuated by forming a large number of predetermined grooves on the contact surface, it is possible to improve wear resistance and uneven wear resistance by forming such grooves.

However, since the paper feed roller (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 generated there. The coefficient also changes with the progress of wear. 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 formed on the contact surface due to wear during use.

Microcracks generated by frictional contact between an elastic body and a rigid body (including paper) grow rapidly and form a steady ablation pattern. However, the ablation pattern, which is a periodic corrugated pattern, varies depending on the friction conditions. Under constant friction conditions (usage conditions), since the pitch pitch and depth are determined, whatever the initial friction surface shape will eventually be the abrasion pattern shape determined by this friction condition. . That is, the initial friction coefficient is expressed by the initial friction surface shape, but if a new abrasion pattern is formed as the wear progresses, the friction coefficient expressed here will depend on the formed abrasion pattern. Changes with the friction coefficient of. 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 shape of the abrasion pattern formed during use is determined by the wear resistance of the rubber material that makes up the paper feed roller and the size of the load applied to the roller during use, and a paper feed device based on a paper feed mechanism that uses friction is used. Under the conditions of use, an abrasion pattern having the shape and size described above is formed.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A sheet feeding roller 5 according to a preferred embodiment of the present invention will be described below with reference to the drawings. The paper feed roller 5 is made of 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 of the present invention is a material having a viscosity of 5 × 10 ⁵ centipoise or less at 100 ° C., and preferably 1 × 10 ⁵ centipoise or less from the viewpoint of effects. From the viewpoint of the molecular weight, the number average molecular weight of the low molecular weight material is 20,0.
00 or less, preferably 10,000 or less from the viewpoint of effects,
It is more preferably 5,000 or less. Usually, a liquid or liquid material at room temperature is preferably used. Further, both hydrophilic and hydrophobic low molecular weight materials can be used.

As the low molecular weight material, any material can be used as long as it satisfies the above-mentioned conditions, and there is no particular limitation, but examples thereof include the following materials. Softening agent: Mineral oil-based, vegetable oil-based, synthetic oil-based softener for various rubbers or resins. Examples of the mineral oil-based oil include process oils such as aromatic oils, naphthene oils, and paraffin oils. Examples of vegetable oils include castor oil, cottonseed oil, linseed oil, rapeseed oil, soybean oil, palm oil, coconut oil, peanut oil, wood wax, pine oil, olive oil and the like. Examples of the synthetic oil type include aromatic type. Plasticizer: phthalic acid ester, phthalic acid mixed base ester,
Various ester-based plasticizers such as aliphatic dibasic acid esters, glycol esters, fatty acid esters, phosphoric acid esters, and stearic acid esters, epoxy-based plasticizers, other plasticizers for plastics, phthalate-based, adipate-based,
Sebacate-based, phosphate-based, polyether-based, polyester-based, etc. plasticizers for NBR. Tackifier: various tackifiers such as coumarone resin, coumarone-indene resin, phenol terpene resin, petroleum hydrocarbon, and rosin derivative (tackifier). Oligomer: Crown ether, fluorine-containing 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 Chloroprene, etc.), silicone-based oligomers, various oligomers such as poly-α-olefins. Lubricants: hydrocarbon lubricants such as paraffin and wax, fatty acid lubricants such as higher fatty acids 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 acid poly Ester-based lubricants such as glycol esters, alcohol-based lubricants such as fatty acid alcohols, polyhydric alcohols, polyglycols and polyglycerols,
Various lubricants such as metal soaps and 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 or fish oil: honey, fruit, or chocolate,
Organic solvents such as dairy products such as yogurt, hydrocarbons, halogenated hydrocarbons, alcohols, phenols, ethers, acetals, ketones, fatty acids, esters, nitrogen compounds, sulfur compounds: Alternatively, various medicinal components, soil modifiers, fertilizers, petroleum, water and aqueous solutions are suitable. These components may be used alone or in combination of two.

Low molecular weight materials are required properties of rubber compositions, applications,
Further, in consideration of the compatibility with the medium material and the rubber material, which are other components of the present invention, the optimum one is selected and used in the optimum amount.

The medium material in the present invention is a material having a function as a medium of a low molecular weight material and a rubber material, and is an important component for achieving the object of the present invention. Specifically, in order to enable a uniform composition of a large amount of low molecular weight material and rubber material,
By using a large amount of low molecular weight material and medium material, first obtain a low molecular weight material holding medium material composite that holds a large amount of low molecular weight material, and combine this with a rubber material to hold the target large amount of low molecular weight material. The polymer composition is intended to be obtained. Even if the low molecular weight material, the medium material and the rubber material are mixed at the same time, a uniform rubber composition having a low elastic modulus cannot be obtained. Further, even if a large amount of a low molecular weight material and a rubber material are directly mixed to obtain a rubber material containing a large amount of a low molecular weight material, the low molecular weight material may not be uniformly mixed, and bleeding often occurs. The desired rubber composition having a low elastic modulus cannot be obtained. Here, "holding" the low molecular weight material means that the low molecular weight material is uniformly dispersed in the medium material and the rubber material and does not bleed or the bleeding is suppressed. Of course, the degree of bleeding can be easily controlled depending on the purpose of the rubber composition. Finally, when the low molecular weight material-holding medium composite is mixed with the rubber material, the uniform mechanism of uniform dispersion in the material is not always clear, but many of the composites are divided into fine particles. It is believed to be retained in the rubber material.

As the medium material of the present invention, any material can be used as long as it has a function as described above and can form a composite that holds a large amount of low molecular weight materials, but is usually a thermoplastic polymer material. Alternatively, various materials having the polymer material as a constituent element are 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 various thermoplastic elastomers, as well as hydrogenated products thereof, and modified products thereof, styrene type,
ABS type, olefin type (ethylene type, propylene type,
Ethylene propylene type, ethylene styrene type, propylene styrene type, etc.), acrylic ester type (methyl acrylate type, etc.), methacrylic acid ester type (methyl methacrylate type, etc.), carbonate type, acetal type, nylon type, halogenated poly Ether type (chlorinated polyether type, etc.), halogenated olefin type (vinyl chloride type, tetrafluoroethylene type, fluorinated-ethylene chloride type, fluorinated ethylene propylene type, etc.), cellulose type (acetyl cellulose type, ethyl cellulose type, etc.) ), Vinylidene-based, vinyl butyral-based, alkylene oxide-based (propylene oxide-based, etc.) thermoplastic resins, and rubber-modified products of these resins. Among them, thermoplastic elastomers are preferably used from the viewpoint of effects.

Among these, it is preferable that a portion where a hard block such as a crystal structure or an agglomerated structure is easily formed and a soft block such as an amorphous structure are mixed together.

A part of the low molecular weight material, the medium material and the low molecular weight material-holding medium material composite according to the present invention is disclosed in JP-A-5-23.
9256 and Japanese Patent Laid-Open No. 5-194763. As the medium material, a material having a three-dimensional continuous network skeleton structure disclosed in this publication is also suitably used as a typical one in the present invention. For example, a hydrogenated product of a butadiene polymer or a butadiene-styrene copolymer is used. Examples thereof include hydrogenated products of polymers and ethylene-propylene copolymers. Among them, hydrogenated products of butadiene polymers and hydrogenated products of butadiene-styrene copolymers are more preferable. The hydrogenated product of the butadiene polymer preferably has a hydrogenation rate of 90% or more. This hydrogenated product can have various molecular structures depending on the composition of 1,4 bonds and 1,2 bonds of the butadiene polymer as a starting polymer and the composition distribution thereof. Due to this molecular structure, the hydrogenated product can include segments having various crystal characteristics such as crystallinity, amorphousness, and characteristics having both crystallinity and amorphousness in one molecular chain.

Specifically, the crystalline characteristic segment of the hydrogenated product is (1) a crystalline segment (S1) consisting of an ethylene block mainly containing ethylene units based on the hydrogenation of 1,4-bonded butadiene units (S1), ( 2) Amorphous segment (S based on the hydrogenation of 1,4-bonded butadiene units and 1,2-bonded butadiene units) which is mainly composed of blocks each containing an ethylene unit and a butylene unit.
2) etc. can be mentioned.

The hydrogenated product of the butadiene polymer in the present invention preferably has a segment having crystal characteristics having both crystallinity and amorphousness.

Among them, those having both the crystalline segment (S1) composed of the ethylene block and the amorphous segment (S2) composed of the block containing the ethylene unit and the butylene unit are preferable. In this case, even if the ethylene block in one molecular chain is one block,
Alternatively, it may exist as two or more multi-blocks.
Further, the ratio of the ethylene block in one molecular chain is 5 to
It is 80%, and from the viewpoint of effect, it is preferably 10 to 70%. Furthermore, the number average molecular weight of this hydrogenated product is 3 × 10.
⁴ or more, preferably 5 × 10 ⁴ or more in terms of effects.

The hydrogenated product of the butadiene-styrene copolymer preferably has a hydrogenation rate of 90% or more. This hydrogenated product can have various molecular structures depending on the composition of 1,4 bonds, 1,2 bonds and styrene part of the butadiene part of the starting copolymer and its composition distribution. Due to this molecular structure, the hydrogenated product has crystallinity, cohesiveness, amorphousness, characteristics having both crystallinity and amorphousness, characteristics having cohesiveness and amorphousness, and crystallinity and cohesiveness in one molecular chain. It is possible to include a segment having various crystal characteristics such as a characteristic having both an amorphous property and an amorphous property.

Specifically, the crystalline characteristic segment of this hydrogenated product is (1) a crystalline segment (S1) consisting of an ethylene block mainly containing ethylene units based on the hydrogenation of 1,4-bonded butadiene units (S1), ( 2) Amorphous segment (S based on the hydrogenation of 1,4-bonded butadiene units and 1,2-bonded butadiene units) which is mainly composed of blocks each containing an ethylene unit and a butylene unit.
2), (3) Cohesive segment (S3) consisting of styrene block mainly containing styrene unit, (4) Block containing mainly butylene unit and styrene unit based on hydrogenation of 1,2-bond butadiene unit and styrene unit, respectively. Amorphous segment consisting of (S4), (5) 1,
Amorphous segments (S5) composed of blocks mainly containing ethylene units, butylene units, and styrene units based on hydrogenation of 4-bond butadiene units, 1,2-bond butadiene units, and styrene units can be exemplified.

The hydrogenated product of the butadiene-styrene copolymer in the present invention has the characteristics of having both crystallinity and amorphousness, the characteristics of having both cohesiveness and amorphousness, and the combination of crystallinity, cohesiveness and amorphousness. It is preferable to have a segment of crystalline properties such as those that have.

Of these, the following hydrogenated substances are preferably used. In the case of a hydrogenated product having both a crystalline segment (S1) composed of the ethylene block and an amorphous segment (S5) composed of the block containing the ethylene unit, butylene unit and styrene unit, the ethylene block in one molecular chain Can be a single block, or 2
It may exist as one or more multi-blocks. Also,
The ratio of the ethylene block in one molecular chain is 5 to 80.
%, From the viewpoint of effect, it is preferably 10 to 70%. Further, the number average molecular weight of this hydrogenated product is 3 × 10 ⁴ or more, and from the viewpoint of effect, it is preferably 5 × 10 ⁴ or more.

A cohesive segment (S3) composed of the styrene block and an amorphous segment (S2) composed of a block containing the ethylene unit and the butylene unit.
In the case of a hydrogenated product having both and, it is preferable that the styrene block in one molecular chain exists as two or more multiblocks. The ratio of the styrene block in one molecular chain is 5 to 60%, and from the viewpoint of effect, it is preferably 10 to 50%. Further, the number average molecular weight of this hydrogenated product is 3 × 10 ⁴ or more, preferably 5 from the viewpoint of the effect.
× 10 ⁴ or more.

A crystalline segment (S1) composed of the ethylene block, a cohesive segment (S3) composed of the styrene block, and an amorphous segment (S) composed of a block containing the ethylene unit and the butylene unit.
2) and / or the hydrogenated product having an amorphous segment (S5) composed of a block containing the ethylene unit, the butylene unit and the styrene unit together, the ethylene block, the styrene block and the amorphous substance in one molecular chain Any of the sex segments may exist as one block or as two or more multiblocks. The ratio of the amorphous segment in one molecular chain is 20 to 90%, and from the viewpoint of the effect, it is preferably 30 to 85%. Further, the number average molecular weight of this hydrogenated product is 3 × 10 ⁴ or more, preferably 5 from the viewpoint of the effect.
× 10 ⁴ or more.

The ethylene-propylene copolymer preferably includes an ethylene-propylene binary copolymer and an ethylene-propylene-diene terpolymer. As a preferred ethylene-propylene-based copolymer, the proportion of the crystalline segment consisting of an ethylene block mainly containing ethylene units is 5 to 60%, and from the viewpoint of effect, 7 to 50%.
And the ratio of the crystalline segment consisting of the propylene block mainly containing propylene units is
A copolymer and the like, which are 60% and 7 to 50% in terms of effects, can be mentioned.

Although various thermoplastic elastomers such as hydrogenated products of these butadiene polymers, hydrogenated products of butadiene-styrene copolymers and ethylene-propylene copolymers are mainly used alone, two or more kinds thereof are used. You may blend and use.

The medium material in the present invention is not particularly limited, but it 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 order to obtain a low molecular weight material-holding medium material composite 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 or less, and the effect point is high. From the above, both materials are selected so that it is preferably 2.5 or less. If this difference exceeds 3, it is difficult to hold a large amount of low molecular weight material from the viewpoint of compatibility, which is an obstacle to lowering the elastic modulus of the rubber composition, and bleeding of the low molecular weight material tends to occur, which is preferable. Absent.

Furthermore, the weight ratio of the low molecular weight material to the medium material is 1.
0 or more, preferably 2.0 or more from the viewpoint of effect,
3.0 or more is more preferable. If this weight ratio is less than 1.0, it becomes difficult to obtain a rubber composition having a very low elastic modulus, and the object of the present invention cannot be achieved.

As a method for producing a composite containing a low molecular weight material and a medium material, an optimum method including a known method may be used depending on the type, characteristics, mixing ratio, etc. of the low molecular weight material and the medium material, and is not particularly limited. The method described in JP-A-5-239256 mentioned above is also one method.

The rubber material (B) used for the paper feed roller 5 is ethylene propylene rubber, ethylene propylene diene ternary co-weight, from the viewpoint of environmental conditions and required performance to be used as the paper feed roller 5 mounted in the paper feeder. United rubber, natural rubber,
Isoprene rubber, styrene-butadiene rubber, butadiene rubber, and polynorbornene rubber are used alone or as a blend.

In the paper feed roller 5 according to the present invention, the difference between the solubility parameter values of the low molecular weight material and the rubber material (B) is 4.0 or less, preferably 3.0 or less. Is 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),
Also in this case, the compatibility between the low molecular weight material and the rubber material (B) becomes a problem. If the difference in this parameter exceeds 4.0, the low molecular weight material retained in a large amount in the composite (A) is difficult to retain in the rubber material (B) from the viewpoint of compatibility, and the hardness of the rubber composition is This is unfavorable because it causes a decrease in the temperature and bleeding of the low molecular weight material is likely to occur.

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 of the paper feed roller 5 according to the present invention can be easily obtained.

The rubber composition can be controlled to have a desired hardness in the low hardness region. For example, the measured temperature 25
An Asker C hardness at 0 ° C. of 10 or less can easily be achieved.

Additives (sulfur, peroxide, etc.) to the rubber composition, vulcanization accelerators (tetramethylthiuram monosulfide (Nocceller TS), mercaptobenzothiazole (Noccer M), N-cyclohexyl-2-benzothiazylsulfene) Amides (Noccellar CZ), diphenylguanidine (Noccellar G), etc., vulcanization aids (ethylene glycol dimethacrylate (EDMA), triallyl isocyanurate (TAIC), N, N'-m-phenylene dimaleimide (Varnock PM) Etc.), various fillers (carbon black, white carbon, white wax flower CC
Etc.), antiaging agents (styrenated phenol (Antage SP-P), 2,6 diterphenyl butyl-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 the paper feed roller 5 mounted in the paper feed device of the present invention.

The rubber composition may further contain the following fillers, if necessary. That is, clay, diatomaceous earth, talc, barium sulfate, calcium carbonate, magnesium carbonate, metal oxides, mica, graphite, scale-like inorganic fillers such as aluminum hydroxide, various metal powders, wood chips, glass powders, ceramic powders , Granular or powder solid filler such as granular or powder polymer, and other various natural or artificial short fibers, long fibers (for example, straw, hair, glass fiber, metal fiber, other various polymer fibers, etc.) be able to.

In the rubber composition, 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 workability and loss characteristics during the production of the paper feed roller are reduced. From the viewpoint of 100 parts by weight of the rubber material, 400 parts by weight or less, preferably 10 to 300 parts by weight, more preferably 20 to 20 parts by weight.
0 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, the cleaving and permanent distortion (set) of the sheet feeding roller 5 become large.

The JIS-A hardness of the sheet feeding roller 5 according to the present invention is 60 ° or less, preferably 50 ° or less, more preferably 40 ° or less, and most preferably 30 ° or less, which is suitable for a sheet feeding device. It can be designed and controlled within a range suitable for the paper feed roller 5 mounted.

FIGS. 1 and 2 show an embodiment of the paper feed roller 5 according to the present invention. The paper feed roller 5 has a large number of grooves 6 on its outer peripheral surface orthogonal to the paper conveying direction. In addition, it comprises a large number of groove ridges 7 orthogonal to the paper transport direction.

3 to 15 are views in which the roller is cut along the radial direction and extended in the horizontal direction, showing the crests 8 and the groove bottoms 9 of the groove crests 7, and the gap between the adjacent groove bottoms 9. That is, the interval between the groove crests 7 (the length of the bottom of the groove crests 7) is P, the horizontal distance from the groove bottom 9 to the crest 8 is l, and the height of the groove crests 7, that is, the height from the groove bottom 9 to the crest 8 is set. Is t, the width of the groove 6 is W,
The depth was H and the groove interval was L. The abrasion pattern formed on the friction surface by abrasion of the elastic body due to repeated friction between the elastic body and the rigid body has a cross-sectional shape shown in FIGS. Although the interval P between the groove crests 7, the horizontal distance l from the groove bottom 9 to the crest 8 and the height t of the groove crests 7 are different depending on the wear resistance of the elastic material and the conditions used as the roller, Under general use conditions as the paper feed roller 5, 0.05 mm ≦ P ≦ 2 mm, −0.05 ≦ l / P ≦ 0.
5, 0.02 mm ≦ t ≦ 0.5 mm is preferable.

In the paper feeding roller 5 utilizing friction, not only the stability of the coefficient of friction expression but also the improvement of wear resistance are essential for ensuring stable paper feeding and conveying performance. In the paper feed roller 5 of the present invention, the groove 6 formed on the outer peripheral surface of the roller can block surface waves causing wear and damp vibrations, so that wear resistance can be improved. If the groove width W of the groove 6 is too small, both sides of the groove 6 come into contact with each other by an external force, so that the effect of the groove 6 is lost. On the other hand, if the groove width W is too large, the contact area with the rigid body (paper) is reduced, so that not only the friction coefficient is reduced, but also abnormal vibration is induced or abnormal destruction is brought about. The groove width W is 0.1 mm ≦
W ≦ 2 mm is preferred. Generally, the deeper the groove depth H is, the greater the wear-damping effect is, but the more easily the paper feed roller 5 is broken. Therefore, the groove depth H is 0.5 mm ≦ H ≦
2 mm is preferred. If the groove interval L is too small, the lateral rigidity of the surface of the paper feed roller 5 is reduced, causing a decrease in the friction coefficient and abnormal destruction. If it is too large, the damping effect of forming the groove 6 is lost. Therefore, the groove interval L is preferably 1 mm ≦ L ≦ 20 mm.

In the embodiment shown in FIG. 3, the bottom 10 of the groove 6 is formed in a plane perpendicular to the side surface. In the embodiment shown in FIG. 4, the bottom 11 of the groove 6 is formed at an acute angle. In the embodiment shown in FIG. 5, the bottom 12 of the groove 6 is formed into a curved surface having a radius R. The relation between the radius R and the groove width W is preferably 2R ≧ W. Cracks are less likely to occur in the curved bottom 12 than in the flat bottom 10 and the acute bottom 11. Also in the embodiment shown in FIG. 6, the bottom 13 is formed into a curved surface and 2R> W as in the case of FIG. Figure 7-
In each of the examples shown in FIG. 15, the groove ridges formed on the friction surface of the roller have a triangular or trapezoidal cross section. The elastic material used as the paper feed roller 5 is a polymer material such as general vulcanized rubber, unvulcanized rubber, or thermoplastic rubber.
From the point of view of the invention, it is desirable to select an elastic material having excellent wear resistance.

Next, the paper feeding roller of the embodiment shown in FIG. 3 was mounted on a paper feeding device for a copying machine by using paper feeding rollers having appropriately changed dimensions, and the paper feeding performance and paper feeding performance were tested. The rotation direction is the direction of the arrow in FIG. The results are shown in Table 1. Note that * 1 in Table 1 is the measured value of the dynamic friction coefficient of each roller (the material to be rubbed: the upper surface of plain paper), and * 2 is the paper feed roller after 100,000 sheets of plain paper (A4 horizontal direction) have been fed by the paper feeding device. (Feed roller)
The wear depth is the wear depth calculated from the wear loss.

[0048]

[Table 1]

In Example 1 in Table 1, 100 parts by weight of rubber EPDM (Nordel 1040 manufactured by DuPont) and paraffin oil of a low molecular weight material (Sunbar 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 mixing Brabender as a composite (low molecular weight material-holding medium composite material) held at 20 parts by weight is put into a predetermined mold and vulcanized and cured at 160 ° C. for 30 minutes to make a roller. A paper feed roller 5 having a predetermined groove and groove on the outer periphery 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 to add predetermined grooves and groove ridges to the outer circumference of the roller. The paper feed roller 5 was manufactured.

In Example 4 in Table 1, the rubber composition prepared in the same manner as in Examples 1 and 2 was put into a predetermined mold, vulcanized and cured, and a predetermined groove was added to the outer circumference of the roller. The paper roller 5 was surface-polished to manufacture the paper feed roller 5.

In Comparative Example 1 in Table 1, Examples 1, 2, and
A rubber composition prepared in the same manner as in Nos. 3 and 4 was placed in a predetermined mold and vulcanized and cured to manufacture a paper feed roller 5 in which only predetermined grooves were added to the outer circumference of the roller.

In Comparative Example 2 in Table 1, a rubber composition prepared in the same manner as in Examples 1 to 4 and Comparative Example 1 was vulcanized and cured in the same manner as in Example 4 to form a predetermined groove on the outer circumference of the roller. The added paper feed roller 5 was subjected to surface polishing by a conventional method to manufacture the paper feed roller 5.

In Comparative Example 3 in Table 1, the rubber composition prepared in the same manner as in Examples 1 to 4 and Comparative Examples 1 and 2 was put into a predetermined mold, vulcanized and cured, and then surface polishing was performed. Thus, the paper feed roller 5 having a predetermined groove on the outer circumference of the roller was manufactured.

In Comparative Example 4 in Table 1, the rubber compositions prepared in the same manner as in Examples 1 to 4 and Comparative Examples 1 to 3 were put in a predetermined mold, vulcanized and cured, and the outer periphery of the roller was predetermined. The paper feed roller 5 having the grooves and groove ridges was manufactured.

In Comparative Example 5 in Table 1, the rubber compositions prepared in the same manner as in Examples 1 to 4 and Comparative Examples 1 to 4 were put into a predetermined mold, vulcanized and cured, and then surface polishing was performed. Was applied by the conventional method to manufacture the paper feed roller 5.

In Comparative Example 6 in Table 1, the rubber compositions prepared in the same manner as in Examples 1 to 4 and Comparative Examples 1 to 5 were put into a predetermined mold, vulcanized and cured, and the surface thereof was not affected. The paper feed roller 5 was manufactured without being processed.

In Comparative Example 7 in Table 1, instead of the low molecular weight material-holding medium composites of Examples 1 to 4 and Comparative Examples 1 to 6, low molecular weight material paraffinic oil (Sun Sun Oil Co., Ltd.
150) A rubber composition prepared by mixing 80 parts by weight of Brabender was put into a predetermined mold and vulcanized and cured to manufacture a paper feed roller 5 having predetermined grooves and groove ridges.

In Comparative Example 8 in Table 1, the rubber composition prepared in the same manner as in Comparative Example 7 was put in a predetermined mold, vulcanized and cured to form a predetermined groove and groove. The paper feed roller 5 was manufactured by subjecting the paper to a polishing process by a conventional method.

The characteristics compared in Table 1 are based on the following tests. (1) Hardness: 25 × 25 × manufactured under the same conditions as each roller
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 roller
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 left for 2.2 hours, the contamination of the plain paper surface and the appearance of the sample were visually confirmed. (3) Abrasion amount: 100,000 sheets of plain paper (A4 longitudinal direction) were passed through the sheet feeding device, and the amount of change in roller radius calculated from the abrasion loss before and after this was taken as the amount of sheet abrasion.

As is clear from the results shown in Table 1, a rubber composition obtained by mixing the low molecular weight material-holding medium composite (A) with the rubber material (B) was distributed, and a predetermined amount was provided on the outer peripheral surface of the roller. The paper feed roller 5 according to the present invention, which has a large number of grooves, is a paper feed roller 5 which exhibits good frictional force retention properties and excellent paper feed characteristics, and is free from appearance contamination and paper contamination. The sheet feeding device of the present invention (including a combination with a feed roller having a roller outer peripheral surface subjected to conventional polishing processing)
It is recognized that the paper feeding device has excellent paper feeding characteristics.

[0062]

As described in detail above, according to the paper feed roller of the present invention, there is no problem of paper contamination or appearance even during long-term use, and the roller surface (friction surface) is formed by abrasion when the roller is used. Predetermined groove ridges whose cross-section is similar to the abrasion pattern and has an asymmetrical corrugated shape are formed in advance at right angles to the paper transport direction, so that the vibration damping grooves are also pre-set so as to be orthogonal to the paper transport direction. By forming it, the contact surface condition can be kept constant from the beginning of use to the end of use, and the friction coefficient can be stabilized, resulting in excellent wear resistance, uneven wear resistance, and friction coefficient stability.

According to the paper feeding device of the present invention equipped with this paper feeding roller, stable paper feeding without paper jam can be performed for a long period of time.

The paper feed roller and paper feed device of the present invention can be effectively used as a paper feed roller and paper feed device for OA equipment such as copying machines and printers, as well as for any device having a paper feed mechanism.

[Brief description of drawings]

FIG. 1 is a perspective view of a sheet feeding roller.

FIG. 2 is an enlarged view of a portion A in FIG.

FIG. 3 is an enlarged view in which the roller is cut along the radial direction and extended in the horizontal direction.

FIG. 4 is an enlarged view in which the roller is cut along the radial direction and extended in the horizontal direction.

FIG. 5 is an enlarged view in which the roller is cut along the radial direction and extended in the horizontal direction.

FIG. 6 is an enlarged view of the roller cut along the radial direction and extended in the horizontal direction.

FIG. 7 is an enlarged view in which the roller is cut along the radial direction and extended in the horizontal direction.

FIG. 8 is an enlarged view in which the roller is cut along the radial direction and extended in the horizontal direction.

FIG. 9 is an enlarged view of the roller cut along the radial direction and extended in the horizontal direction.

FIG. 10 is an enlarged view in which the roller is cut along the radial direction and extended in the horizontal direction.

FIG. 11 is an enlarged view of the roller cut along the radial direction and extended in the horizontal direction.

FIG. 12 is an enlarged view in which the roller is cut along the radial direction and extended in the horizontal direction.

FIG. 13 is an enlarged view in which the roller is cut along the radial direction and extended in the horizontal direction.

FIG. 14 is an enlarged view of the roller cut along the radial direction and extended in the horizontal direction.

FIG. 15 is an enlarged view of the roller cut along the radial direction and extended in the horizontal direction.

FIG. 16 is a view showing a conventional paper feeding mechanism.

[Explanation of symbols]

 5 Paper Feed Roller 6 Groove 7 Groove 8 Peak 9 Groove Bottom

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical indication G03G 15/00 510

Claims (4)

[Claims] 1. A low molecular weight material-holding medium composite (A) containing a low molecular weight material and a medium material in a roller outer peripheral surface layer of various paper feeding rollers mounted in an apparatus having a paper feeding mechanism, and a rubber material. (B) and a low molecular weight material having a viscosity of 5 × 10 ⁵ centipoise or less at 100 ° C., and a difference in solubility parameter value between the low molecular weight material and the medium material is 3.0 or less. In addition, the weight ratio of both materials 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 low molecular weight material and the rubber material are Is 0.3 or more, the medium material is a hydrogenated product of a butadiene polymer or a butadiene-styrene copolymer having a three-dimensional continuous network skeleton structure, and the rubber material is Ethylene propylene rubber, ethylene propylene di En terpolymer rubber, natural rubber, isoprene rubber, styrene butadiene rubber, butadiene rubber, polynorbornene rubber or blended rubbers of these, with a number of grooves for damping wear on the outer peripheral surface that contacts the paper and retaining the carrying force A plurality of groove ridges having an asymmetrical corrugated cross section are formed at right angles to the paper transport direction, and the plurality of grooves formed on the outer peripheral surface are The width is W, the depth is H, and the groove interval is L. 0.1 mm ≤ W ≤ 2 mm 0.5 mm ≤ H ≤ 2 mm 1 mm ≤ L ≤ 20 mm formed on the outer peripheral surface If a large number of groove peaks having an asymmetrical cross-section are provided, the distance between the groove peaks is P, the horizontal distance from the groove bottom to the peak is l, and the height of the groove peaks is 0.05 mm ≤ P ≤ 2 mm -0. 05 ≦ l / P ≦ 0.5 0.02mm ≦ t ≦ 0.5mm Paper feed roller, wherein the formed it as. 2. The paper feed roller according to claim 1, wherein grooves on the outer peripheral surface and groove ridges having an asymmetrical corrugated section are provided by a method of transferring a shape which is previously formed on a mold. 3. The paper feed roller according to claim 1, wherein after forming a large number of grooves on the outer peripheral surface, groove ridges having an asymmetric corrugated cross section are added by surface polishing. 4. A sheet feeding device provided with a plurality of sheet feeding rollers for feeding a sheet by friction, wherein at least one of the plurality of rollers is the sheet feeding roller according to any one of claims 1 to 3. Characteristic paper feeding device.