JP3446854B2 - Paper feed roller - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to various paper feed rollers such as a pickup, a feed and a reverse, which are used in a paper feed device of various office automation equipment such as a copying machine, a facsimile and various printers.

[0002]

2. Description of the Related Art Conventionally, EPDM (ethylene / propylene / diene rubber), NSX, silicone rubber, etc. have been used for rollers and belts for feeding and carrying various OA equipment.
Materials such as urethane rubber are used.

[0003]

However, these rubber materials have the problems of a decrease in the friction coefficient (μ) due to blooming and a decrease in the weather resistance, and the use of paper powder or the like causes the friction coefficient to decrease due to the long-term use. There is also the problem that the rate of change is large.

Further, since a low-grade rubber material contains a large amount of a plasticizer, it contaminates a printed matter. For example, in an ink jet printer, the ink is repelled at a roller contact portion due to the influence of the plasticizer or the like. Roller marks are left. In addition, the paper feed roller, which is made of low hardness rubber and has its surface polished, may cause so-called "white spots" due to abrasion powder on the paper and contaminate the photosensitive drum. There is a problem such as being lost.

In view of such circumstances, the present invention has a sufficient frictional force for conveying a sheet, minimizes changes in the surface state due to friction, and provides a stable conveying force for a long period of time. It is an object of the present invention to provide a sheet feeding roller that can be held, has less contamination on printed matter, and has excellent low temperature characteristics, weather resistance, and ozone resistance.

[0006]

[Means for Solving the Problems] The present invention for achieving the above-mentioned object
A first aspect of the present invention is a sheet feeding roller made of a thermoplastic elastomer, the hardness of which is 1 on the Shore A scale.
The thermoplastic elastomer is in the range of 0 ° to 30 °, and the thermoplastic elastomer is a thermoplastic elastomer material composed of a polyester thermoplastic elastomer, a polyvinyl chloride thermoplastic elastomer, and a polystyrene elastomer, and 100 parts by weight of the thermoplastic elastomer material. 20 to
A roller for sheet feeding, which is made of a polymer alloy type material containing 40 parts by weight of a plasticizer.

A second aspect of the present invention is the first aspect.
The thermoplastic elastomer further comprises 5 to 20 parts by weight of a softening agent polymer based on 100 parts by weight of the thermoplastic elastomer material.

A third aspect of the present invention is the first or second aspect.
In the above, the surface roughness of the sheet feeding roller is the sheet feeding roller characterized in that R _MAX is in the range of 17 to 48 μm.

[0009] A fourth aspect of the present invention, any of the first to third
In the above embodiment, the plasticizer is dioctyl phthalate, dibutyl phthalate, di (heptyl, undecyl)
At least one selected from the group consisting of phthalate, diisooctyl phthalate, diheptyl phthalate, butylbenzyl phthalate, higher alcohol phthalate, paraffin-based process oil, naphthene-based process oil, aromatic-based process oil, and epoxy-based plasticizer. The paper feed roller is characterized by that.

[0010]

[0011]

The thermoplastic elastomer constituting the paper feed roller of the present invention is a polymer alloy type material composed of at least two kinds of thermoplastic polymer materials. here,
The thermoplastic elastomer material as a component of the polymer alloy type material is selected from the group of ester-based, vinyl chloride-based, styrene-based, olefin-based, and amide-based thermoplastic elastomers, and particularly polyester-based thermoplastic elastomers and chlorinated It is preferable to contain a vinyl-based thermoplastic elastomer and a polystyrene-based elastomer.
The blending ratio of these polymers is 30 to 30%, respectively.
60% by weight, 30-50% by weight, and 0-30% by weight
It is preferable to select from the range.

Further, the thermoplastic elastomer of the present invention is
As an accessory component, 20 to 40 parts by weight, and preferably 25 to 35 parts by weight of a plasticizer are contained with respect to 100 parts by weight of the thermoplastic elastomer material. As a result, the polymer alloy type material has properties very close to those of vulcanized rubber, and the problem of reduction in friction coefficient due to blooming peculiar to sulfur vulcanized rubber is solved.

Here, as the plasticizer, dioctyl phthalate, dibutyl phthalate, di (heptyl, undecyl) phthalate, diisooctyl phthalate, diheptyl phthalate, butyl benzyl phthalate and higher alcohol phthalates such as phthalates; paraffins Mineral oil-based softeners such as process oils, naphthene-based process oils and aromatic-based process oils; or epoxy-based plasticizers can be mentioned, and one or more of them can be selected.

Further, the thermoplastic elastomer of the present invention is
In addition to the thermoplastic elastomer material and the plasticizer, a softening agent polymer such as low molecular weight polystyrene, alkyd resin, polyethylene or polypropylene may be contained in order to impart softening property to the elastomer. It is desirable to add 5 to 20 parts by weight of these softening agent polymers to 100 parts by weight of the thermoplastic elastomer material.

Further, the thermoplastic elastomer forming the paper feed roller of the present invention includes, in addition to the thermoplastic elastomer material and the plasticizer, other additives such as antioxidants within a range not impairing the object of the present invention. Agent, UV absorber,
It goes without saying that the coloring amount and the like may be contained if necessary.

The hardness of the paper feed roller of the present invention is
It is in the range of 10 ° to 30 ° on the Shore A scale. This is because the deformation amount (nip amount) under a constant pressure load is increased to improve the sheet feeding characteristics.

Further, the paper feed roller of the present invention preferably has a surface roughness R _MAX in the range of 17 to 48 μm in order to minimize the reduction of the friction coefficient due to paper powder or the like.

[0019]

Since the paper feed roller of the present invention is formed by using a specific thermoplastic elastomer, there are problems such as weather resistance and a decrease in friction coefficient due to blooming which cannot be solved by conventional rubber materials. It was resolved.

Further, in particular, by mainly polyester polymer, vinyl polymer and poly styrenic polymers chloride, mechanical strength, and properties of excellent heat resistance and durability, weather resistance, ozone resistance and It also has the property of excellent aging resistance.

Further, by adopting a low-hardness thermoplastic elastomer material, and by making the surface thereof have R _MAX in the range of 20 to 45 μm, the coefficient of friction is high, but tack (extremely high hardness) like low hardness urethane is obtained. The force of adhering to the adherend in a short time with a light force does not increase, and it is possible to prevent the friction coefficient from decreasing due to the influence of paper powder.

Furthermore, the thermoplastic elastomer of the present invention is economical because it is excellent in recyclability.

Further, the thermoplastic elastomer of the present invention is
When the roller is used as a paper feed roller, the core portion of the roller made of high hardness plastic such as ABS resin can be two-color molded together, so that the manufacturing process can be simplified and the cost of the roller can be reduced.

[0024]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in more detail with reference to Examples, but these Examples do not limit the scope of the present invention in any way.

Blends 1 to 4 shown in the following table for the polyester-based thermoplastic elastomer, polyvinyl chloride-based thermoplastic elastomer, and polystyrene-based thermoplastic elastomer.
A polyethylene polymer and a plasticizer (dioctyl phthalate) were further added to the polyalloy type material contained in 1. in the following blending amounts to produce a roller made of a thermoplastic elastomer.

Specifically, a polyester thermoplastic elastomer (Toray DuPont: Hytrel (trade name)), a polyvinyl chloride thermoplastic elastomer (Mitsubishi Kasei Vinyl: Sunplane (trade name)), and Polystyrene thermoplastic elastomer (made by Asahi Kasei Corporation:
Each pelletized material of Tufte (trade name) is kneaded with a table-top twin-screw extruder / kneader (MP2015 type; manufactured by Tubaco Yokohama Sales Co., Ltd.), and then heated at 160 ° C by an electric heating roll (Yokoyama Kikai Seisakusho )), A polyethylene polymer (manufactured by Sanyo Kasei: Sunflex (trade name)) and a plasticizer (manufactured by Dainippon Ink and Chemicals: Monocizer DOP (trade name)) are mixed, and the mixture is mixed with the thermoplastic elastomer. Added to the mixture material. Next, injection molding machine (IS50
EP-1.5A, Toshiba Machine Co., Ltd. injection pressure 2000
kg / cm ² and molding temperature at the bottom of the hopper: 150
℃, cylinder hopper side: 155 ℃, the same center: 160
C., same nozzle side: 165.degree. C., mold temperature was 50.degree. The roller size is a feed roller: inner diameter 16 mm x outer diameter 24 mm x length 2
3.5mm, reverse roller: inner diameter 17mm x outer shape 2
It was 7 mm × 23.5 mm.

Hardness (Shore A
(Scale) was measured.

From the results shown in Table 1, in the case of the compound 3 having a small amount of the plasticizer of 10 parts by weight, the hardness is 48 and too hard as a paper feeding roller, while in the case of the compound 4 having a large amount of the plasticizer of 50 parts by weight, the settling amount is large. It was too much and could not be used as a paper feed roller.

[0029]

[Table 1]

Next, the surface of each roller was polished with a precision cylindrical grinder (Hi-Gloss-750, manufactured by Kondo Seisakusho Co., Ltd.) to obtain surface roughness of 20 μm and 45 μm, respectively.
The rollers having the surface roughnesses of 20 μm and 45 μm of the formulation 1 were used as Examples 1 and 2, and the rollers having the surface roughnesses of 20 μm and 45 μm of the formulation 2 were used as Examples 3 and 4.

For comparison, the rollers of the formulations 1 and 2 had surface roughnesses of 15 μm and 50 μm, and were designated as Comparative Examples 1 and 2 and Comparative Examples 3 and 4, respectively. Further, for Formulation 3, a roller was used to adjust the surface roughness to
45 μm and 50 μm, and Comparative Examples 5 to 8 respectively
And

A paper feed test was conducted on each roller, and the friction coefficient of each roller at the initial stage and after passing 50,000 sheets was measured by a method according to an actual machine, and the respective sheet passing characteristics were evaluated. The results are shown in Table 2.

[0033]

[Table 2]

From the results shown in Table 2, the paper feed roller is R
It has been found that it is preferable that the _max is in the range of 17 to 48 μm. I.e., the R _max 20 [mu] m is less affected by paper dust, but R _max is very little influence of paper powder is one of the 5 [mu] m, as R _max of 15μm significantly adhesion of paper dust, whereas, R _max is The one having a thickness of 50 μm had a low friction coefficient from the initial stage and was not suitable as a paper feed roller.

[0035]

As described above, since the paper feed roller of the present invention uses a specific thermoplastic elastomer material and contains a specific amount of the plasticizer, it has a sufficient frictional force for conveying the paper. However, changes in the surface state due to friction can be suppressed to a minimum, stable conveying power can be maintained for a long period of time, and there is little contamination of printed materials, and low temperature characteristics, weather resistance, and ozone resistance are excellent. It is a thing.

─────────────────────────────────────────────────── ─── Continuation of front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) B65H 27/00 B41J 13/076

Claims (4)

(57) [Claims] 1. A paper feed roller made of a thermoplastic elastomer, the hardness of which is 10 ° on a Shore A scale.
Is in the range of -30 °, and the thermoplastic elastomer is
A thermoplastic elastomer material comprising a polyester-based thermoplastic elastomer, a polyvinyl chloride-based thermoplastic elastomer, and a polystyrene-based elastomer, and 20 to 40 per 100 parts by weight of the thermoplastic elastomer material.
A roller for sheet feeding, which is made of a polymer alloy type material containing a part by weight of a plasticizer. 2. The thermoplastic elastomer according to claim 1 , further comprising the thermoplastic elastomer material 10.
A paper feed roller comprising 5 to 20 parts by weight of a softening agent polymer based on 0 parts by weight. 3. The paper feed roller according to claim 1 , wherein the surface roughness of the paper feed roller is R _MAX in the range of 17 to 48 μm. 4. The plasticizer according to claim 1 , wherein the plasticizer is dioctyl phthalate, dibutyl phthalate,
From the group consisting of di (heptyl, undecyl) phthalate, diisooctyl phthalate, diheptyl phthalate, butylbenzyl phthalate, higher alcohol phthalates, paraffinic process oils, naphthenic process oils, aromatic process oils, and epoxy plasticizers A paper feed roller characterized by being at least one selected.