JPH08333433A - Urethane membre - Google Patents

Abstract

PURPOSE: To obtain a urethane member which can be designed so that it may have a low coefficient of friction when used in an electrophotographic machine or an electrostatic recording machine, has a stable coefficient of friction even to e.g. paper with an adherent silicone oil and has excellent durability. CONSTITUTION: The urethane member is one comprising a polyol component and an isocyanate component, wherein 10-80 pts.wt. silicone polyol having siloxane bonds in the main chain is added to 100 pts.wt. polyol. Desirably, the polyurethane member contains 1-70 pts.wt. fine silicone powder per 100 pts.wt. polyol component.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a urethane member, and more specifically, to development, toner layer formation, cleaning and feeding used in electrophotographic devices such as copying machines, printers and facsimiles, and electrostatic recording devices. The present invention relates to members such as paper, conveying rollers, blades, and belts.

[0002]

2. Description of the Related Art Conventionally, a large number of members have been used in electrophotographic devices such as copying machines, printers and facsimiles, and electrostatic recording devices, and various processes such as development, toner layer formation, cleaning, paper feeding and transportation are performed during the electrophotographic process. Plays a role. As a member used in these processes, a member having a small coefficient of friction is desired from the viewpoint of mechanical design.

For example, in the case of a developing roller used in a printer, if the friction coefficient between the photosensitive member and the toner layer forming blade is small, the torque for rotating the roller can be designed to be small, and the motor capacity can be small. Can be converted. Further, a toner cleaning blade used in a copying machine or a printer is also required to have a small friction coefficient in order to come into contact with the photoconductor.

Further, regarding a paper feed roller and a feed roller for recording paper used in a copying machine, a printer, and a facsimile, when a plurality of rollers are combined to feed and feed, or a difference in friction coefficient between the roller and the pad, When using it, it is necessary to freely design the coefficient of friction. Especially when the recording paper once printed with a copying machine or a facsimile is fed and conveyed again, the silicone oil adheres to the surface of the recording paper, which reduces the friction coefficient between the paper feed roller and the conveyance roller. There were drawbacks such as being lost. Silicone oil is applied to the surface of the fixing roller in order to prevent toner fusion on the surface of the fixing roller during the electrophotographic process. Silicone-based materials such as silicone rubber are generally used to reduce the size and to perform stable paper feeding and conveyance. However, since silicone-based materials have poor wear characteristics, they have drawbacks such as poor durability as members.

[0005]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and the coefficient of friction can be freely designed, and the coefficient of friction is stable with respect to silicone oil-adhered paper. The purpose is to provide a urethane member having excellent durability.

[0006]

A urethane member mainly comprises a polyol component and an isocyanate component, and 100 parts by weight of the polyol contains 10 to 10 parts of a silicone polyol having a siloxane bond in the main chain.
80 parts by weight is included. According to a second aspect of the present invention, the urethane member has 1 to 70 parts by weight of silicone fine powder with respect to 100 parts by weight of the polyol component. According to a third aspect of the present invention, the urethane member is used as a sheet feeding roller, a conveying roller, and a developing roller used in a mechanism such as electrophotography.

That is, in the present invention, the addition of silicone polyol to the polyol component of the urethane member reduces wear characteristics, so that it is suitable for developing, feeding and conveying rollers used in mechanisms such as electrophotography. Further, since it is possible to reduce the change in the friction coefficient even for silicone oil-adhered paper, it is most suitable for paper feeding and conveying rollers.
Furthermore, the addition of the fine silicone powder to the urethane member improves the affinity with the silicone oil, so that the change in the friction coefficient with respect to the silicone oil-adhered paper can be further reduced.

[0008]

The present invention will be described in more detail below.
Regarding the type of polyol component used in the present invention,
There is no particular limitation, and any polyol that is commercially available can be used, for example, polyether polyol, polytetramethylene ether glycol, THF-alkylene oxide copolymer polyol, polyester polyol, acrylic polyol, Polyolefin polyols, partially saponified ethylene-vinyl acetate copolymers, phosphate-based polyols, halogen-containing polyols and the like are preferably used.

The isocyanate component used in the present invention is also not particularly limited, and is widely used for TDI and MD.
In addition to I, crude-MDI (polymeric-MDI), and modified MDI, a special isocyanate may be used. Special isocyanates are 1,5-naphthalene diisocyanate, tolidine diisocyanate,
Hexamethylene diisocyanate, isophorone diisocyanate, p-phenylene diisocyanate, transcyclohexane 1,4 diisocyanate, xylylene diisocyanate (XDI), hydrogenation-XDI, hydrogenation-MD
I, lysine diisocyanate, triphenylmethane triisocyanate, tris (isocyanate phenyl)
Thiophosphate, tetramethyl xylene diisocyanate, lysine ester triisocyanate, 1,6
11-undecane triisocyanate, 1,8-diisocyanate-4-isocyanate methyl octane, 1,
3,6-hexamethylene triisocyanate, bicycloheptane triisocyanate, trimethylhexamethylene diisocyanate and the like are preferably used.

The silicone polyol having a siloxane bond in the main chain is referred to as an alcohol-modified silicone oil, and the modified position is at the terminal, side chain,
Or both may be used. The general formula is as follows.

[0011]

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When the amount of the polyol component is 100 parts by weight, the amount of the silicone polyol having a siloxane bond in the main chain is appropriately selected according to the desired friction coefficient, but 10 to 80 parts by weight is preferable. The most preferable range is 10 to 70 parts by weight, and more preferably 10 to 60 parts by weight. If the amount of the silicone polyol having siloxane in the main chain is less than 10 parts by weight, the object of the present invention that the friction coefficient is stable with respect to silicone oil-adhered paper cannot be achieved, and conversely from 80 parts by weight. If it increases, the wear characteristics will deteriorate.

The above weight is the case of the so-called one-shot method in which the polyol component and the isocyanate component are simultaneously mixed in the production of the urethane composition, but in the case of the so-called prepolymer method using the raw material prepolymerized with the polyol and the isocyanate. Also, the weight ratio suitable for the invention is the same. That is, the silicone prepolymer having a siloxane bond in its main chain is contained in 100 to 80 parts by weight of the prepolymer.
It is within the scope of the invention to include parts by weight.

In the present invention, silicone fine powder can be used. As the silicone fine powder, silica whose surface is treated with silicone oil, silicone resin finely powdered, silicone rubber finely powdered, and the like are preferably used, and these may be used as a mixture of two or more kinds. .

The silicone fine powder blended in 100 parts by weight of the polyol component is 1 to 70 parts by weight, preferably 1 to 60 parts by weight, more preferably 1 to 50 parts by weight. When the amount of the silicone fine powder is less than 1 part by weight, the effect of reinforcing the silicone polyol having a siloxane bond in the main chain and the effect of stabilizing the friction coefficient on the silicone oil-adhered paper become small. Conversely, 7
When the amount is more than 0 parts by weight, the hardness of the urethane composition becomes large, which causes problems such as loud sound when used in a copying machine, a printer, a facsimile, etc., which is not preferable. The preferable weight ratio of the prepolymer method is also as described above.

In the present invention, silica may be blended for the purpose of improving durability and abrasion resistance. Silica also has the effect of increasing the reinforcing properties of the silicone polyol.

The paper feeding mechanism in the present invention is a mechanism for supplying recording paper from a cassette tray for accommodating the recording paper in copying machines, printers and facsimiles. Further, the transport mechanism referred to in the present invention is a mechanism for transporting recording paper supplied in a copying machine or a printer to a transfer unit, a fixing unit, an unloading unit, or a document to be transmitted by a facsimile is transported to a document reading unit and separated. The mechanism.

As the urethane member of the present invention, not only an elastomer but also a foam body can be preferably used. The elastomer and foam may be used alone, or two or more layers of elastomer and foam may be combined. When the foam layer is used, the urethane member has a low hardness, and the range of use is expanded in the electrophotographic mechanism.

Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples. [Example 1] 50 parts by weight of polyisoprene polyol having a hydroxyl value of 47, 50 parts by weight of silicone oil modified with a hydroxyl value of 56 at both terminal alcohols, and silicone fine powder 30
After mixing 30 parts by weight and defoaming under reduced pressure for 30 minutes, 13.5 parts by weight of crude diphenylmethane 4,4 ′ diisocyanate having an NCO% of 31.7 and dibutyltin dilaurate 0.0.
01 parts by weight was added, and the mixture was stirred for 3 minutes while defoaming under reduced pressure.

The urethane composition thus prepared was poured into a mold having an inner diameter of 34 mm, cured at 90 ° C. for 16 hours, then released from the mold and polished to a predetermined outer diameter. The JIS-A hardness of the finished roller was 45 degrees.
In order to use this roller as a paper feeding roller, a printer "Laser-Jet-3" manufactured by Hewlett-Packard Co.
/ Si type ”and a paper passing test of 10,000 sheets was performed. The reduction amount of the outer shape of the roller before and after the test was 0.03 mm.

Next, when the ratio of the friction coefficient measured on the paper to which the silicone oil is adhered and the friction coefficient measured on the normal paper is defined as the friction coefficient retention rate, the retention rate on the obtained roller is 80. %Met. As a method of measuring the coefficient of friction, a surface tester (Type: 14DR) manufactured by Heidon was used and a load of 200 g and a moving speed of 100 mm / min. It went on condition of.

Example 2 A paper feed roller was prepared in the same manner as in Example 1 except that the fine silicon powder was not used, and the same evaluation test was conducted.

[Example 3] Hydroxyl value 47, number of functional groups 2.
50 parts by weight of polyisoprene polyol No. 3, 50 parts by weight of silicone oil modified at both ends with a hydroxyl value of 56, 30 parts by weight of silicone fine powder, silicone foam stabilizer 2
Parts by weight and 0.001 parts by weight of dibutyltin dilaurate were mixed and stirred for 2 minutes while incorporating dry air.
The mixture thus produced was poured into a mold having an inner diameter of 34 mm, cured at 70 ° C. for 16 hours, and then demolded to obtain a roller having a density of 0.3 g / cm ³ and a JIS-A hardness of 23 degrees. The same procedure as in Example 1 is performed below.

Example 4 100 parts by weight of an isocyanate-terminated polybutadiene prepolymer having an NCO% of 11.6 and 30 parts by weight of silicone fine powder were mixed and defoamed under reduced pressure for 30 minutes, and then alcohol at both ends having a hydroxyl value of 470 was used. 30 parts by weight of modified silicone oil and 0.001 parts by weight of dibutyltin dilaurate were added, and the mixture was stirred for 3 minutes while degassing under reduced pressure. The same procedure as in Example 1 is performed below.

[Comparative Example 1] A paper feed roller was prepared in the same manner as in Example 1 except that the compounding ratio of the polyisoprene polyol used in Example 1 and the silicone oil modified at both ends with alcohol was changed to 10/90 parts by weight. It was produced and the same evaluation test was performed.

[Comparative Example 2] A paper feed roller was prepared in the same manner as in Example 1 except that the compounding ratio of the polyisoprene polyol used in Example 1 and the silicone oil modified with alcohol at both ends was changed to 95/5 parts by weight. It was produced and the same evaluation test was performed.

Table 1 shows the composition and evaluation result of each of the above Examples and Comparative Examples.

[0028]

[Table 1]

[0029]

EFFECTS OF THE INVENTION The urethane member of the present invention contains 10 to 10 parts by weight of a polyol component and 10 to 10 parts by weight of a silicone polyol.
By containing 80 parts by weight, the friction coefficient can be freely designed, and the friction coefficient is stable against silicone oil-adhered paper, etc., and the durability is excellent. Suitable for conveying or developing rollers.

Claims (5)

[Claims] 1. A silicone polyol having a siloxane bond in its main chain is contained in an amount of 10 to 8 mainly composed of a polyol component and an isocyanate component, and 100 parts by weight of said polyol.
A urethane member containing 0 part by weight. 2. The urethane member according to claim 1, wherein the urethane member contains 1 to 70 parts by weight of silicone fine powder with respect to 100 parts by weight of the polyol component. 3. A sheet feeding roller mounted on an apparatus having a sheet feeding mechanism, wherein the sheet feeding roller elastic layer is the urethane member according to claim 1 or 2. . 4. The various transport rollers mounted on an apparatus having a transport mechanism, wherein the transport roller elastic layer is the urethane member according to claim 1 or 2. 5. An electrostatic latent image formed by forming an elastic layer having conductivity on the outer periphery of a good conductive shaft, and carrying a developer on the surface of the elastic layer to form a thin layer of the developer. In the developing roller for visualizing, the elastic layer is the urethane member according to claim 1 or 2.