JP2902011B2 - Separation claw for copier - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an extremely reliable separation claw for a copying machine, which is excellent in heat resistance, heat resistance and heat resistance, and is excellent in the shape of the tip (edge) of the separation claw. It is.

2. Description of the Related Art In a conventional apparatus such as a dry copying machine, a latent image formed on the surface of a photosensitive drum corresponding to a character or a figure is converted into a toner image, and then the toner image is supplied to a supply cassette. The toner image is transferred to the paper surface supplied from the printer, and the surface is heated and pressed by a fixing roller heated to fix the transferred toner image to the paper surface. There is a built-in mechanism to keep you from leaving. Then, in order to ensure that the copy paper that has passed through the fixing roller is discharged without being wrapped around the roller, a method of scooping up the end of the copy paper using a separation claw while keeping the leading end thereof in close contact with the outer peripheral surface of the roller is adopted. . Therefore, in such a separation claw, the outer peripheral surface of the roller has a small abrasion resistance and does not damage the surface, has sufficient mechanical strength, particularly high-temperature rigidity, and has sufficient accuracy in the shape of the tip. In addition, characteristics such as not adhering the toner have been required.

In recent years, especially in recent years, digitalization has led to the so-called intelligent copying, which has not only simple copying functions but also unprecedented high-resolution image processing and editing functions, as well as facsimile functions and input / output devices for other OA equipment. Copiers have been developed, and in such multifunctional, complex, and systemized copiers, demands for higher speed, higher reliability, and longer life have been stronger than ever before.
Now, with regard to the separation claw, the heating speed of the fixing roller is often set to a higher temperature due to the high speed, so that even higher heat resistance is required, and as a part of the system, copying is always possible. Because it will be exposed to high temperatures for an extremely long time, it must have excellent thermal fatigue resistance, and be able to properly follow various conditions due to multi-functionality. Because the connection can be considered, in order to demonstrate the separation function more reliably, the excellent nail tip that can guarantee the heat load resistance of the nail tip that can withstand an accident such as a paper jam and the reliable separation function of repetition Shape is required.

Among the various properties required for such a separation claw, many proposals have been made for improving the non-adhesiveness to toner, for example, by forming a film of a fluororesin or a fluorinated polyether polymer on the separation claw. And a method of kneading a non-adhesion improver such as a fluororesin into the material of the separation nail. However, high-temperature stiffness, thermal fatigue resistance, thermal load resistance, thermal shock resistance, non-aggressiveness of the mating roll, etc. are greatly affected by the type of heat-resistant resin or filler used in the separation nail material, and are satisfactory strategies. Is not widely adopted. That is, as the conventionally used separation claw material, polyimide, polyamide imide, polyphenylene sulfide, polyether ketone, polyether sulfone, polyether imide, aromatic polyester and the like can be mentioned. In order to function as a separation nail material at the above high temperature, resins such as ordinary heat-resistant polyethersulfone and polyetherimide have a glass transition point of around 220 ° C. and are amorphous, so If the temperature is higher than the temperature, the resin softens and the heat resistance is too low to satisfy the demand for the improvement in heat resistance accompanying the speeding up of the copying machine. There are also heat-resistant polyethersulfone and heat-resistant polyetherimide having a glass transition point of 250 ° C. or higher, but are inferior in lubricity and abrasion resistance, sometimes causing an increase in roller driving torque and poor separation. Even if a coating such as a fluororesin is applied, the sliding contact surface with the roller wears out during long-term use, and the separation claw base material and the roller slide. Therefore, poor lubricity and abrasion resistance of the base material are unsatisfactory in terms of extending the life and improving the reliability. In addition, among polyphenylene sulfide or polyimide resin, a thermosetting polyimide resin that forms a three-dimensional network is fragile, so that glass fibers, potassium titanate fibers, heat-resistant fibers such as carbon fibers, or these. By reinforcing effect based on adding inorganic powdered filler such as mica and talc to fiber,
Although heat resistance is greatly improved, there is the problem of damaging the mating roll, the reliability problem that the heat deformation property is remarkably reduced if these reinforcing agents are poorly filled at the tip of the nail, and furthermore, they are exposed to high temperatures for a long time. As a result, there is also a problem that it is difficult to prolong the service life, that is, it becomes brittle by being gradually oxidized and crosslinked. Further, the polyamideimide resin has a heat resistance of 250 ° C. or more as a separating claw material without adding a reinforcing agent, but has a disadvantage that the heat resistance is reduced when water is absorbed (or absorbed moisture). When a large amount of water is absorbed,
Heat resistance becomes worse. Specifically, when the molded article is rapidly heated at the time of absorbing water, the moisture inside the molded article becomes high-pressure steam, and the molded article becomes a certain amount or more, for example, 5 × (1/1).
2) For sheet specimens of × (1/8) cubic inch, (1/8)
It is well known that the minimum temperature at which a thick surface of an inch undergoes a dimensional change of 2.5 μm or more and causes the surface to swell or foam (this is called a thermal shock temperature) is significantly reduced. Although it had a heat resistance of about 280 ° C. at the time of absolute drying, there is a problem that it is lowered to about 210 ° C. due to a large amount of water absorption. Among polyimide resins, there is a polyimide resin made of a polymer having a very large molecular weight called a thermoplastic polyimide, for example, polyimide "Vespel" manufactured by DuPont of the United States. Since molding is not possible, it is excellent in terms of heat resistance, but is not suitable for practical use.

In contrast to these resins, aromatic polyester resins, especially thermotropic liquid crystal polymers that can be melt-molded and show anisotropy when melted, show a liquid crystal-specific orientation, which results in self-reinforcement, Although it improves its own heat deformation resistance, the variation in the manifestation of self-strengthening due to this orientation is large, and if this is small, the thermal deformation temperature as a separation nail material is also lowered, resulting in poor reliability and repeated fatigue. Since it is strong, there is a problem that it is inferior in long-term heat load resistance. On the other hand, the polyether ketone resin has a glass transition point of less than 250 ° C. like the polyphenylene sulfide resin, but because it is a crystalline resin, it maintains the same heat resistance as the polyphenylene sulfide resin or fills with inorganic powder. The heat resistance is improved by reinforcing hardening based on the addition of an agent, but unlike polyphenylene sulfide resin, the resin itself has toughness, so the amount of reinforcing agent is small, and the reinforcing effect such as potassium titanate fiber is not Since it can be reinforced only with fibers that are small but have little damage to the mating material, the mating roll has low aggressiveness and hardly develops brittleness due to oxygen cross-linking, and is excellent in heat aging resistance. Further, since a phenomenon such as a decrease in thermal shock temperature due to water absorption such as polyamide-imide resin does not occur, as a separation nail material, JP-A-60-2574 is used.
No. 67 and those reinforced with potassium titanate fibers as disclosed in Japanese Patent Application Laid-Open No. 61-27575 have been used, but they do not satisfy the demand for improved reliability and longer life. Absent. That is, although excellent in heat aging resistance as described above, the glass transition point is 250 ° C. or less, specifically, 1
Since the temperature is around 50 ° C., the elastic modulus is greatly reduced at a temperature higher than this, and the heat-resistant deformation resistance is maintained by reducing the degree of the decrease with a reinforcing agent. On the other hand, since the surface temperature of the fixing roller of a copying machine is generally 150 ° C. or higher, especially in the range of 170 ° C. to 250 ° C., there is a problem of nail tip deformation under a high-temperature load. There is a problem of creep deformation when a large force is applied to the tip of the claw, that is, heat resistance load resistance. In addition, there is a problem that physical properties such as elastic modulus tend to decrease rapidly because of being exposed to a temperature higher than the glass transition point for a long time, that is, so-called thermal fatigue resistance is not good. Furthermore, the radius of curvature at the tip of the nail is too small as compared with the polyamide-imide resin, resulting in a sharp edge of less than 10 μm, and a good radius of curvature (10 to 50 μm) can be obtained during die processing. Also, if sharp edges tend to appear due to scars on the mold due to fillers, etc., the high-temperature rigidity at the tip of the nail decreases, causing thermal deformation, resulting in poor separation, and the outer peripheral surface of the roller There was a danger of damaging them.

[Problems to be solved by the invention]

As described above, in the conventional technology, heat deformation resistance, heat aging resistance, heat shock resistance, heat fatigue resistance, heat load resistance, non-attack to the mating roll and high reliability with excellent tip shape, There has been a problem that a separation claw for a copying machine having a long life has not been obtained, and it has been a problem to solve this problem.

[Means for solving the problem]

In order to solve the above problems, in the present invention, a polycyano aryl ether resin composition containing 100 parts by weight of a polycyano aryl ether resin and 20 to 150 parts by weight of a heat-resistant fiber having an average fiber diameter of 3 μm or less is formed. Then, a means for forming a separating claw for a copying machine having a radius of curvature of 0.01 to 0.05 mm at the tip of the claw is adopted. The details are described below.

First, the polycyano aryl ether resin used in the present invention is: Is represented by the repeating unit alone or And other repeating units, specifically within a range that does not lose the original properties of the polycyanoaryl ether resin,
It is a polymer coexisting in an amount of about 20 mol% or less. Such a polycyano aryl ether is, for example, a solution of p-chlorophenol as a solvent at a concentration of 0.2 g / dl at 60 ° C.
The reduced viscosity (ηsp / C) is preferably 0.3 dl / g or more. These are commercially available, for example, from Idemitsu Kosan Co., Ltd. as polyether etryl (ID300). The method for producing the polycyano aryl ether is described in JP-A-63-3059.
This is disclosed in the embodiments of Japanese Patent Publication No.

Next, the heat-resistant fiber powder in the present invention refers to a molding temperature of a polycyano aryl ether resin (330 to 400 ° C).
Means fibers that can withstand, specifically, glass fibers, carbon fibers, graphite fibers, ceramic fibers, rock wool, slag wool, potassium titanate whiskers, magnesium whiskers, aluminum borate whiskers, silicon carbide whiskers, Steel wire,
Examples thereof include copper wires, stainless steel wires, silicon carbide fibers, and aromatic polyamide fibers. The shape of these fibers is such that the surface roughness of the molded product of the separation claw is small and smooth, and the radius of curvature of the tip of the separation claw is 0.1 m as a preferable range.
Since the accuracy is required to be not more than m, preferably not more than 0.05 mm, it is important that the fiber diameter is not more than 6 μm. If such fibers are used, the surface roughness of the molded product is 1-3 μm.
m or less, and the radius of curvature of the separation claw is also 0.
It becomes 05mm or less. However, if the radius of curvature of the tip of the separation claw is small, it is not sufficient. Even if the edge is too small and a sharp edge (burr) is obtained, and a good radius of curvature is obtained during mold processing, If the curvature becomes extremely small due to a scar etc. attached to the mold due to fillers, etc., and sharp edges are likely to appear, the high-temperature rigidity of the tip of the nail decreases, causing thermal deformation, and the outer peripheral surface of the roller There is a danger of damaging the device.

In contrast, a composition in which 20 to 150 parts by weight of a heat-resistant fiber having a fiber diameter of 3 μm or less is added to 100 parts by weight of a polycyanoaryl ether resin eliminates the disadvantages described above. It has been found that a molded product having a separated claw having an excessive radius of curvature (0.01 to 0.05 mm) over a long period of time can be obtained.

In addition, the addition of these heat-resistant resins prevents a remarkable decrease in the elastic modulus at a temperature higher than the glass transition point (around 145 ° C.) of the polycyano aryl ether resin, and particularly, deforms the nail tip under a high-temperature load, especially paper. Deformation under high load such as clogging is eliminated.

Furthermore, after molding the polycyano aryl ether resin composition, the tip of the nail is deformed under a high-temperature load by performing a heat treatment at a temperature of 180 ° C. or more, preferably 250 ° C. or more, for 2 hours or more, preferably 4 hours or more. Was found to be significantly improved.

It is preferable to add an adhesiveness improver and a thixotropic agent within a range not to impair the object of the present invention, and other various fillers may be added. Here, the adhesiveness improver is added to increase the adhesive strength between the coating agent to be coated on the surface of the separation nail molding and the separation nail molding in order to improve the non-adhesion of the separation nail to the toner. For example, a thermosetting resin having at least one group of an epoxy group, a carboxyl group, a hydroxyl group, a phenoxy group, a methylol group, and an amino group is preferable, and specifically, a phenol resin or an epoxy resin. Can be mentioned. The thixotropy-imparting agent, when the composition of the present invention is melted, refers to those that provide a thickening effect at a low shear rate, specifically, fine powder silica, fine powder talc, diatomaceous earth, and the like. By adding these, variations in the film straightness and radius of curvature of the tip of the separation claw are further improved.
Other fillers include antioxidants, heat stabilizers, ultraviolet absorbers, lubricants, mold release agents, coloring agents, flame retardants, flame retardant assistants, antistatic agents which are added to ordinary resin compositions. Abrasion resistance improver (eg, graphite, carborundum, silica powder, molybdenum disulfide, fluororesin, etc.), tracking resistance improver (eg, silica, graphite, etc.), and other fillers (eg, ,
Glass beads, glass balloons, calcium carbonate, alumina, talc, diatomaceous earth, clay, kaolin, gypsum, calcium sulfite, mica, metal oxides, inorganic pigments, etc.
Substances stable at 300 ° C. or higher).

[Action]

Polycyano aryl ether resin and average fiber diameter 3μm
The combination of the following heat-resistant fibers not only prevents adverse effects on the radius of curvature of the tip and surface smoothness, but also makes it impossible to obtain smooth curves or sometimes sharp edges with conventional separation nails. (Burr), even if a good radius of curvature is obtained during mold processing, scars on the mold due to corrosive gas coming out of resin or compounded fillers during the long-term use For example, the shape of the tip of the separation claw deteriorates, the radius of curvature becomes very small, and sharp edges tend to appear, and a molded product that can maintain an appropriate radius of curvature for a long time cannot be obtained. Remarkable elasticity at temperatures above the glass transition point without impairing the excellent thermal shock resistance and flame retardancy of polyaryl ether resins. Pressing a reduction in, further 180 ° C. or more of these shaped articles, preferably above 250 ° C. temperature, 2
By performing heat treatment for at least 4 hours, preferably at least 4 hours,
It has the effect of further increasing the heat load resistance and the heat fatigue resistance at high temperatures.

〔Example〕

The raw materials used in Examples and Comparative Examples are collectively shown as follows, and the respective abbreviations are shown in []. The mixing ratios of these raw materials were all expressed in parts by weight.

Polycyano aryl ether resin [PEN] Idemitsu Kosan Co., Ltd .: Polyether nitrile ID300, polyether ether ketone resin [PEEK] ICI, UK: Victrex 450P, Liquid crystal polymer [LCP] Dartco, USA: Aroma Group polyester resin XYDAR-S
RT300, polyphenylene sulfide resin [PPS] manufactured by Toprene: T-4, potassium titanate whisker [PTW] manufactured by Otsuka Chemical: Tismo D102, fiber diameter: 0.1 to 0.3 μm,
Fiber length 20-30 μm, epoxy silane treated product, glass fiber [GF-3] manufactured by Asahi Fiberglass: Milled fiber, fiber diameter 3 μm, fiber length 50 μm, glass fiber [GF-6] manufactured by Asahi Fiberglass: chopped strand , Fiber diameter 6 μm, fiber length 3 mm, aminosilane coupling treated product, glass fiber [GF-13] manufactured by Asahi Fiberglass: Chopped strand, fiber diameter 13 μm, fiber length 3 mm, aminosilane coupling treated product, aluminum borate whisker [ BALW] Shikoku Chemicals: Arbolex, average fiber diameter 0.5 to 1.0
μm, average fiber length 10-30 μm, carbon fiber [GF-7] manufactured by Toho Rayon Co., Ltd .: Vesfight HTA, fiber diameter 7.2 μm
m, fiber length 6 mm, graphite [GRP] manufactured by Nippon Graphite Co., Ltd .: ACP. Among the above raw materials, liquid crystal polymer [LCP] was used by pulverizing a pellet to an average particle diameter of 50 μm using a refrigeration pulverizer.

Examples 1-8: After preliminarily dry-mixing each raw material at the mixing ratio shown in Table 1, the mixture was fed to a twin-screw extruder (PCM-30, manufactured by Ikegai Iron Works Co., Ltd.) and melted under the conditions of a cylinder temperature of 340 ° C and a screw rotation speed of 50 rpm. It was kneaded and granulated. The obtained pellets were injection-molded under the conditions of a cylinder temperature of 350 ° C, an injection pressure of 800 kg / cm ² , and a mold temperature of 210 ° C. The width was 12.7 mm, the length was 126 mm, and the thickness was
A 3.2 mm plate material and a test piece having the same shape as the separating claw used in the Fuji Xerox Copier Model 2700 were obtained. Among these test pieces, the separation nail test pieces prepared for investigating the practical functionality of the damage of the roller were all fluorinated polyether polymers having isocyanate groups at the terminals (Montison, Italy; Bryn Z-DISOC 200
0) was immersed in a Freon 113 solution in which it was dissolved at a concentration of 2.0% by weight, taken out of the solution, and subjected to an aging treatment at about 200 ° C. for 2 hours. Note that, except for Examples 3 and 4, no heat treatment was performed after molding, but in Example 3, heat treatment was performed at 180 ° C. for 2 hours, and in Example 4, heat treatment was performed at 250 ° C. for 4 hours.

The bending strength, the radius of curvature of the tip, the surface smoothness, the thermal fatigue resistance, the thermal load resistance, and the practical functionality of the above test pieces were evaluated. These evaluation methods are as follows.

1) Flexural strength Based on ASTM-D790.

2) Radius of curvature at the tip Using a projector V-16D manufactured by Nippon Kogaku Co., Ltd., the values are shown in the minimum and maximum ranges of the measured values at n = 100. However, 5
If it is smaller than 1 μm, it cannot be measured with high accuracy.
m.

3) Surface smoothness Using a surface roughness meter (Dektak II type, manufactured by Nihon Vacuum Co.)
The surface roughness of the roller contact portion of the separation claw was measured.

4) Thermal fatigue resistance due to nail shape Using a nail tip thermal deformation tester (schematic diagram shown in Fig. 1), roller surface temperature 250 ° C, nail tip load 20g, contact angle (θ) 100 °, contact time 1 minute Under each condition of 1 hour and 12 hours, the amount of deformation t (see FIG. 2) when the test (n = 10) was performed was measured, and the average value was calculated and expressed.

5) Heat load resistance due to claw shape Roller surface temperature using the same testing machine as heat fatigue resistance
The amount of deformation t (see FIG. 2) was measured when the test (n = 10) was performed at 250 ° C., a contact angle (θ) of 100 °, a contact time of 1 minute, and a nail tip load of 20 g, 40 g, and 100 g. The average was calculated and expressed.

6) Non-aggressive dry copier (Fuji Xerox Co., Ltd .: Model 2700)
Attach a test piece of the same shape as the separation claw used for it, pass 99 sheets of B5 size separation paper continuously, 50,000 sheets in total, and measure the degree of scratches on the surface of the fixing roll and a surface roughness meter. The shape of the sliding portion of the separation claw was checked before and after the operation, and the roller had a wear depth of less than 5 μm (marked with ◎), 5 to 15 μm
(O) and those exceeding 15 μm (△) were evaluated in three grades.

 Table 2 summarizes the results obtained in the above tests.

Comparative Examples 1 to 8: Except that each raw material was blended in the ratio shown in Table 3 The same operation as in Example 1 was performed to produce a plate-shaped test piece and further a separation claw, and the same characteristics as in Examples 1 to 8 were examined. Table 4 summarizes the obtained results.

The following can be said from Tables 2 and 4. That is, in Examples 1 to 8, the bending strength is good, and the accuracy of the radius of curvature of the tip and the surface smoothness are all good values.
In addition, heat resistance and heat load resistance are excellent, and Examples 3 and 4 which have been heat-treated are particularly excellent. On the other hand, even when the heat-resistant fiber having a fiber diameter of 3 μm or less is used, Comparative Example 1 in which the addition amount is less than 10% by weight has excellent surface smoothness, but the tip R becomes too small, and so-called burrs are formed. This is not preferable, and as a result, the damage to the mating roller is also poor. Further, it is inferior in heat resistance fatigue resistance and heat resistance load resistance. Conversely, Comparative Example 2 in which more than 150 parts by weight was added was thought to be due to poor dispersibility of the additive. However, the dispersion of the tip radius of curvature was large, and the flatness of the flat surface was poor. It is also very damaging. Further, as heat-resistant thermoplastic resins other than the polycyanoaryl ether used in the present invention, a polyetheretherketone resin, a liquid crystal polymer and a polyphenylene sulfide resin, and Comparative Example 3 in which heat-resistant fibers having a fiber diameter of 3 μm or less were respectively blended, In Comparative Examples 4 and 5, the amount of deformation in both short-time and low-load areas is small in heat-resistant fatigue resistance and heat-resistant load resistance. Do not use nails. Furthermore, even if a polycyano aryl ether resin is used, Comparative Examples 6, 7 and 8 using heat-resistant fibers having an average fiber diameter exceeding 3 μm have too small variations in the radius of curvature of the tip. Comparative Examples 7 and 8 were poor in surface smoothness, not only poor in damage to the mating roller, but also poor in thermal fatigue resistance and thermal load resistance.

〔effect〕

As described above, the separation claw for a copying machine of the present invention comprising a polycyanoaryl ether resin and a composition containing a heat-resistant fiber having an average fiber diameter of 3 μm or less as an essential component has the polycyanoarylether resin originally provided. In addition to flame retardancy and thermal shock resistance, it is excellent in thermal fatigue resistance and thermal load resistance, and is not aggressive to the opponent roll and retains the shape of the precise nail tip formed with a predetermined radius of curvature at the tip. Therefore, it has a highly reliable copy paper separating function especially in continuous use at high temperatures, and is most suitable for applications requiring a long life. Therefore, it is not only a device having a copying function, but also a so-called intelligent copying machine equipped with an unprecedented high-resolution image processing, editing function, facsimile function or input / output device of other OA equipment due to digitization etc. It can be fully utilized. Therefore, it can be said that the significance of the present invention is extremely large.

[Brief description of the drawings]

FIG. 1 is a schematic diagram of a nail tip thermal deformation tester, and FIG. 2 is a diagram showing the amount of nail tip deformation. 1 ... separation claw, 2 ... heat roller, 3 ... load, θ ... contact angle, t ... deformation amount.

Claims (2)

(57) [Claims] 1. A molded article of a polycyanoaryl ether resin composition comprising 100 parts by weight of a polycyanoaryl ether resin and 20 to 150 parts by weight of a heat-resistant fiber having an average fiber diameter of 3 μm or less as an essential component. Curvature radius 0.01 to 0.05
A separating claw for a copying machine, which is formed in mm. 2. A separating nail for a copying machine according to claim 1, wherein the molded article of the composition is a molded article heat-treated after molding.