JP2713705B2 - Dry copier - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dry copying machine. 2. Description of the Related Art A dry-type copying machine, which has undergone rapid progress and development with the socialization of information, uses an electrostatic latent image formed on the surface of a photosensitive drum corresponding to characters, figures, etc. of a document as a toner. After the toner image is converted into an image, the toner image is transferred to the paper surface supplied from the paper supply cassette, and the surface is heated and pressed by a heated fixing roller to fix the transferred toner image on the paper surface. It has a mechanism for fusing the image and the paper fibers so that they do not separate easily. However, in such a device, for example, in the final fixing step, the paper heated and pressed by the fixing roller rotates while keeping in close contact with the roller surface, and there is a great risk of causing paper jams. It is important to lift the edge of the paper that is in close contact with the roller by using a separation claw whose tip is pressed against the surface of the roller to smoothly separate it. Therefore, it is natural that the separation claw needs to have heat resistance so that the tip does not deform, but at the same time, the radius of curvature of the tip (hereinafter, abbreviated as the tip R).
Is small (for example, 0.1 mm or less, preferably 0.05 mm
mm or less) or lubricating the separation claw,
It is important to prevent poor separation (hereinafter, referred to as a poor separation direction) or paper jam at a separation claw (hereinafter, simply referred to as a paper jam), which causes the fixing paper to be sent to the fixing roller side. Further, the surface of the fixing roller is 170-27.
Since the temperature rises to 0 ° C., the toner adhered to the paper fuses to the separation claw, and if the amount increases, the fused toner may cause paper jam or cause the toner adhering to the paper to be scraped off. In many cases, white streaks (hereinafter referred to as nail marks) are formed in the toner fixing portion of the toner, so that the separating nails must be non-adhesive to the toner in order to avoid this. [0006] In order to satisfy the conditions to be met by such a separating claw, conventionally, polyimide, polyamideimide, polyarylene sulfide, aromatic polyetherketone, aromatic polysulfone, aromatic polyetherimide, aromatic polyamide, aromatic polyamide, Resins such as polyester or those obtained by mixing such resins with fluororesins such as tetrafluoroethylene resin or graphite or other solid lubricants. Further, for example, Japanese Utility Model Publication No. 54-18921,
As disclosed in JP-A-1111569, a resin in which the surface of a resin as described above is coated with a fluorine-containing polymer to improve lubricity and non-adhesion has been put to practical use. [0007] However, the separation claw whose surface is not coated with a fluorine-containing polymer has insufficient lubricity and non-adhesiveness even if mixed with a fluororesin or a solid lubricant, so that paper jamming occurs. Even with separation nails that cause the problem of nail marks and that have a surface coated with a fluorine-containing polymer, both the expected lubricity and anti-adhesion are insufficient, and long-term continuous use or depending on the type of toner, paper The problem of jamming and nail marks occurs as in the case described above. In general, the thickness of the coating film at the tip of the separation claw is 30 μm on average in order to exhibit lubricating and non-adhesive effects.
Since at least 10 μm or more is required, the tip R of the separation claw formed to have a small angle by coating is large, and a separation direction defect, paper jam, and the like are likely to occur. Therefore, in order to prevent the tip R of the separation claw from increasing due to the thickness of the coating film, a measure may be taken to reduce the tip R in consideration of the film thickness when forming the separation claw. However, in such a treatment, the tip is naturally susceptible to thermal deformation, not only lowering the usable temperature, but also the resin-made separation claw body and the fluorine-containing polymer are not usually firmly bonded. Therefore, interface peeling of the coating film easily occurs, and in order to coat the fluorine-containing polymer, a method of applying a fluorine-containing polymer dispersed in a polar solvent to about 20 to 40 μm by spraying is usually adopted. In addition, there are many problems, for example, since the splash is scattered around the separation claw, the product yield is reduced, and the cost is very high. There is an attempt to form a thin film of silicone oil on the surface of the separation claw by, for example, a dipping method so as to exhibit lubricity and non-adhesiveness. Maintenance is impossible. [0010] As described above, the tip coating of the separation claw based on the prior art has lubricating properties, non-adhesiveness, and the like.
None of them are excellent in all aspects of adhesion strength and thin film forming ability, and there is a problem that undesired phenomena such as thermal deformation, poor separation direction, paper jam, and nail marks often occur. Means for Solving the Problems In order to solve the above-mentioned problems, in the present invention, the surface of the roller is 170 to 170.
A dry copying machine comprising a fixing roller heated to a temperature of 270 ° C., and a separation claw made of an aromatic polyetherketone resin which can be used continuously at an ambient temperature of 150 ° C. or more by separating the fixing paper from the fixing roller. Thus, a dry copying machine in which at least the surface layer of the separation claw made of the aromatic polyetherketone resin is coated with a fluorinated polyether polymer is provided. Alternatively, at least the surface layer at the tip end of the separation claw of the dry copying machine is The main structural unit is used to cover with a fluorinated polyether polymer which is terminally bonded by at least one polar group. DESCRIPTION OF THE PREFERRED EMBODIMENTS First, a fixing roller according to the present invention
The fixing roller is heated to a temperature of 0 to 270 ° C. The aromatic polyetherketone resin of the present invention has a mechanical strength that can be used continuously as a fixing paper separating claw at an ambient temperature of 150 ° C. or more. Ude, a trade name
Synthetic resin such as polyetheretherketone resin commercially available as 1-PEEK. Next, the fluorinated polyether polymer having at least one polar end group used in the present invention comprises -C _X1 F _2X1 -O- units (where X ₁ is 1 to 4).
Is the main structural unit, and the number average molecular weight is about 1000
~ 5000 polymers, for example: And particularly preferably, A fluorinated polyether polymer having an average molecular weight of about 2000, which is commercially available under the trademark Fomblin Z-DISOC (registered trademark of Montenson, Italy) represented by the following formula: ## STR5 ## A fluorinated polyether polymer having an average molecular weight of about 2,000 and sold under the trademark Fomblin Z-DEAL (registered trademark of Montenson, Italy) represented by the following formula: ## STR6 ## And a fluorinated polyether polymer having an average molecular weight of about 2000 and sold under the trademark Fomblin Z-DOL of Montenson, Italy. The viscosity of the fluorinated polyether polymer is too high to form a thin film of the fluorinated polyether polymer in order to impart lubricity and non-adhesiveness to the separation claw for a copying machine. For example, Fomblin Z-DOL200
0 at a temperature of 20 ° C. is about 80 cst.
nZ-DEAL2000 has a viscosity of about 20c at 20 ° C.
st. Fluorinated polyether polymer is chlorofluorocarbon 11
It may be dissolved in a highly fluorinated organic solvent such as 3 and applied by an appropriate method, for example, a spraying method or a dipping method, but the dipping method is preferable. This is because the yield of the coating liquid is very good. The concentration of the fluorinated polyether polymer dissolved in the highly fluorinated organic solvent is not particularly limited, but considering the cost, it is preferably about 0.3 to 10% by weight, and in order to obtain a particularly effective thin film. About 0.5 to 3% by weight is preferable. Furthermore, after painting and drying, brush the surface with a soft cloth or tissue paper, etc.
The slightly cloudy surface state is regarded as glossy.
This is to remove excess fluorinated polyether polymer. The above-mentioned method, that is, a fluorinated polyether polymer is dissolved in an appropriate concentration of a highly fluorinated organic solvent in a base resin of a separated nail, and a coating is formed by an appropriate coating method such as dipping. Dry at an appropriate temperature, for example, in a hot air (50 ° C.) drying oven to remove the fluorinated organic solvent. The treatment may be carried out at a higher temperature after or also for the drying, and it is preferable in view of the possibility of increasing the reactivity between the polar terminal group of the fluorinated polyether and the resin of the separated nail matrix. For example, the solution containing the fluorinated polyether polymer is applied by dipping to the surface of a base material having a separated claw shape obtained by injection molding, and then subjected to 250-27.
Heat treatment at a high temperature of 0 ° C. for an appropriate time. Here, the high temperature refers to a temperature at which the base resin and the fluorinated polyether do not thermally deform or thermally decompose. Hereinafter, Examples and Comparative Examples are shown, and the mixing ratios of the raw materials are all expressed by weight%. EXAMPLE 1 30% potassium titanate whiskers (Tismo D101, manufactured by Otsuka Chemical Co., Ltd.) are melt-blended with aromatic polyetherketone resin (PEEK-150P, manufactured by ICI, UK) to produce pellets. This was injection-molded to obtain a separated claw-shaped molded product and a friction test piece. Further, as a fluorinated polyether polymer, Fomblin Z-DI manufactured by Montenson Inc.
SOC (number average molecular weight 2000) was chosen. That is,
In Example 1, a fluorinated polyether polymer was used. This was immersed in a 1.5% dissolved Freon 113 solution, applied, taken out, dried and heat-treated in a hot-air drying oven at 50 ° C., and then lubricated, non-adhesive, and separated nail material. The functionality as was evaluated. The method of each evaluation is as follows. Lubricity: Using a thrust type friction tester, load 1 kg / c
The bearing steel (SUJ2) was tested under the conditions of m ² and a speed of 1 cm / sec. Non-adhesion: The contact angle between water and acetic acid was determined using a goniometer-type contact angle tester manufactured by Elma Optical Co., Ltd. using the separation nail as a test piece. Functionality as Separating Claw: Using a dry copying machine Z-60, manufactured by Sharp Corporation, a test piece having the same shape as the separating claw of the same type was attached in a fixed position, and 50,000 sheets of A4 size copy paper were continuously passed. Paper and repeat 50,000 times,
Number of copies at the time of paper separation failure (paper jam) from the fixing roller, presence / absence of toner image contamination due to claw marks, amount of toner attached to separation claw [not attached or a small amount attached (marked with ◎) , A relatively small amount (marked with ○), a small amount (marked with Δ), and a large amount (marked with ×)]. Further, the toner adhered to the separation nail after the paper passing test was wiped off with ethyl alcohol, and then the contact angles with water and acetic acid were measured. The obtained result is
It is summarized in the table. [Table 1] Comparative Example 1 A test piece was obtained in exactly the same manner as in Example 1 except that the coating film of the fluorinated polyether polymer was not formed on the surface of the separation nail, and the same measurement was carried out. Also shown in Table 1. As is clear from Table 1, the separation claws shown in Example 1 have excellent lubricity, and exhibit a contact angle comparable to that of a fluororesin alone even in non-adhesiveness, and are extremely excellent. As a result, the practical functions of the copying machine were sufficiently satisfactory. Also, the contact angle after the paper passing test showed a large value similar to that before the test, and there was a large difference from the contact angle of Comparative Example 1.
Satisfactory results were obtained in both adhesion strength and abrasion resistance of the coating. Comparative Examples 2 to 8: As heat-resistant resins for separating nails, Comparative Examples 2, 3 and 8 are aromatic polyamide-imide resins made by Amoco, USA: To
Comparative Example 4 was an aromatic polyamideimide resin, Torlon 434, manufactured by Amoco, USA, containing rlon4203 (containing 3% titanium dioxide and 0.5% tetrafluoroethylene resin).
7 (12% graphite, 8% ethylene tetrafluoride resin)
Comparative Example 5 is a polyphenylene sulfide resin manufactured by Asahi Glass Co., Ltd .: RE101JA (containing an inorganic filler).
Comparative Example 6 is a polyphenylene sulfide resin manufactured by Asahi Glass Co., Ltd .: RFG1530JA (containing 15% ethylene tetrafluoride resin and 30% glass fiber), and Comparative Example 7 is an aromatic polyether ketone resin ICI UK Manufactured by: PEEK-150P and Teismo D101A which is a potassium titanate whisker manufactured by Otsuka Chemical Co., Ltd. in a weight ratio of 7: 3.
Was used for melt blending at a ratio of These resins were injection-molded in the same manner as in Example 1, and Comparative Examples 2, 3, 4 and 8 were heat-treated at 260 ° C. for 24 hours after molding. Furthermore, Comparative Examples 3 and 5 are polyfluorocarbon tough coat enamel TC7105G manufactured by Daikin Industries, which is a fluororesin-containing resin enamel.
N and TC-7409BK were uniformly coated with a suction type spray gun to a film thickness of about 30 μm.
After drying at 00 ° C. for 30 minutes, Comparative Example 3, ie, TC7
105GN was heat-treated at 250 ° C. for 30 minutes, and Comparative Example 5, ie, TC7409BK, was heat-treated at 180 ° C. for 30 minutes. Further Comparative Example 8 after heat treatment, a fluorinated polyether polymer having no polar group at the end Indonesian Montedjison Co. FomblinZ-25 (20 ℃ viscosity 25 0
cst) was immersed in a solution of 1.5% dissolved in Freon R113, taken out and dried at 50 ° C. The same test as in Example 1 was performed using these test pieces, and the results are shown in Table 2. [Table 2] As is clear from Table 2, the nails having no coating on the surface of the separated nails, that is, Comparative Examples 2, 4, 6 and 7, had poor lubricity and non-adhesiveness, and showed good results in the actual machine test. Could not be obtained. In addition, even if the coating is formed on the nail surface, 30
An increase in the tip R due to a thick film of μm causes poor separation due to lack of lubricity, nail marks due to lack of non-adhesiveness, and an increase in toner adhesion amount. Even when a thin film made of a fluorinated polyether polymer is formed on the nail surface as in Comparative Example 8, the lubricity and non-adhesiveness before the test are extremely excellent, but since there is no polar group at the end, it is coated. The adhesion strength between the sheet and the base material was poor, and the sheet peeled off during the paper passing test, resulting in a poor result.
This is judged by a large decrease in the contact angle after the test. As is apparent from the above, the dry copying machine according to the present invention has excellent heat resistance, lubricity, and non-adhesiveness of the separation claw, improves the adhesion strength between the coating and the base material, and improves the adhesion strength. By reducing the thickness of the coating, it is possible to prevent long-term operation without impairing the separation direction or paper jam due to the increase in the tip R of the separation claw tip, which is a drawback of the conventional coating technology, and without impairing the heat conductivity and electric conductivity. It can withstand continuous use. Therefore, it can be said that the significance of the present invention is extremely large.

Claims (1)

(57) (Claims) (1) A fixing roller in which the surface of the roller is heated to a temperature of 170 to 270 ° C., and a fixing sheet is peeled off from the fixing roller and can be used continuously at an ambient temperature of 150 ° C. or more. Aromatic po
A dry copier comprising a separation claw made of a polyether ketone resin , wherein at least a surface layer at a tip portion of the separation claw made of an aromatic polyether ketone resin is coated with a fluorinated polyether polymer. Dry copier. (2) The fluorinated polyether polymer is represented by the following formula: 2. The dry copying machine according to claim 1, wherein the polymer is a polymer having at least one polar group as a main structural unit.