JPH0658581B2 - Separation claw for copier - Google Patents

Description

The present invention relates to a separating claw for a copying machine.

[Conventional technology]

Dry copiers, which have made rapid progress and development with the informationization of society, convert the electrostatic latent image formed on the surface of the drum corresponding to the characters and figures of the original into a toner image, and then the toner image Is transferred to the paper surface supplied from the paper cassette, and in order to fix the transferred toner image on the paper surface, the surface is heated and pressed by a heated fixing roller to fuse the toner image and the paper fiber. It has a mechanism for wearing them so that they cannot be easily separated. However, in the final fixing step of such an apparatus, for example, the paper heated and pressed by the fixing roller rotates while being in intimate contact with the roller surface, causing a paper jam. It is important to lift the edge of the paper that is in close contact with the roller and smoothly separate it by using a separation claw whose tip is pressed against the surface of the paper. Therefore, it is natural that the separation claw needs heat resistance so that the tip portion is not deformed, but at the same time, the radius of curvature of the tip (hereinafter referred to as tip R
Is short) (for example, 0.1 mm or less, preferably 0.05 mm or less), or the separation claws have lubricity to send the fixing paper to the fixing roller side. It is important to prevent the phenomenon from being simply called “separation failure” or paper jam at the separation claw (hereinafter, simply called “paper jam”). Furthermore, the surface of the fixing roller is 17
Since the temperature rises from 0 to 270 ° C., the toner adhering to the paper is fused to the separation claws, and if this amount increases, paper clogging may be caused by this fused toner and the toner adhering to the paper may be scraped off. Since white streaks (hereinafter referred to as nail marks) often enter the toner fixing portion of the fixing paper surface, the separating claw must be non-adhesive to the toner in order to avoid this.

In order to satisfy the conditions that such a separating claw should have, conventional polyimide, polyamide imide, polyarylene sulfide, aromatic polyether ketone, aromatic polysulfone, aromatic polyether imide, aromatic polyamide,
Resins such as aromatic polyesters, or resins in which fluorine resin such as tetrafluoroethylene resin or graphite or other solid lubricant is mixed, and moreover
As disclosed in JP-A-18921 and JP-A-57-111569, the surface of the above resin is coated with a fluorine resin such as ethylene tetrafluoride to improve lubricity and non-adhesiveness. Improved products have been put to practical use.
However, even if a fluororesin or a solid lubricant is mixed, both lubricity and non-adhesiveness are insufficient, causing problems of paper jam and nail mark, and the surface is coated with fluororesin. Even with the separating nail, neither the expected lubricity nor non-adhesiveness is sufficient, and problems of paper jam and nail mark occur as in the above case depending on long-term continuous use or the type of toner. Generally, the film thickness of the fluorine resin coating film at the tip of the separating claw is 30 μm on average and at least 10 μm or more in order to exert the effect of lubricity and non-adhesiveness. By covering the tip R of the sheet, it becomes large, so that separation failure and paper jam are likely to occur. Therefore, in order to prevent the tip R of the separation claw from becoming large due to the film thickness of the coating film, a measure may be taken in which the tip R is made small in consideration of the film thickness when the separation claw is formed. However, such a treatment naturally causes the tip to be easily deformed by heat and lowers the usable temperature, and the resin-separating claw body and the fluorine resin are not usually firmly bonded to each other. Therefore, interfacial peeling of the coating film is likely to occur. Further, in order to coat the fluorine resin, a method in which the fluorine resin dispersed in a polar solvent is usually applied to about 20 to 40 μm by a spray is adopted, but splashes are scattered around the separating nail. Therefore, there are many problems such as a decrease in product yield and an extremely high cost. There is also an attempt to form a thin film of silicone oil on the surface of the separating claw by, for example, a dipping method or the like to develop lubricity and non-adhesiveness, but it is excellent because it is released from the surface in a short time. It is impossible to maintain such effects over the long term.

[Problems to be solved by the invention]

As described above, the tip coating of the separating claw based on the conventional technology is not excellent in all of the lubrication characteristics, non-adhesiveness, adhesion strength and thin film forming ability, and the thermal separation and other defective separation, paper jamming, etc. However, there is a problem that unfavorable phenomena such as nail marks often occur.

[Means for solving problems]

In order to solve the above problems, in the present invention, at least the surface layer of the tip of the heat-resistant resin separating claw has a polyfluoroalkyl group having 2 to 20 carbon atoms, and the base material of the separating claw. The means of coating with a fluorine-based compound having a polar group having a high affinity with the resin was adopted. The details will be described below.

First, the heat-resistant resin in the present invention, under an atmosphere of 150 ℃ or more, its mechanical strength can be continuously used as a fixing paper separation nail material, for example, commercially available as TORLON, which is a registered trademark of Acomo, Inc. Aromatic polyamide-imide resin, Polyimide resin marketed as VESPEL-SP which is a registered trademark of U.S.A. Deupon, Polyphenylene sulfide resin sold as RYTON which is a registered trademark of Phillips Co., United States, United Kingdom Polyetheretherketone resin marketed as Udel-PEEK, which is a registered trademark of ICI, or polyethersulfone resin marketed as Udel-PES, a registered trademark of General Electric Company, USA Polyetherimide resin commercially available as ULTEM and EKONOL which is a registered trademark of Carborundum, Inc. It refers to a synthetic resin such as aromatic polyester resin which is commercially available in.

Next, the fluorine-based compound used in the present invention is a polyfluoroalkyl group having 2 to 20 carbon atoms, for example, And polar groups, e.g., -NCO, -OH, -SH, -COOH , -SO 3 H, shall apply in -SO ₂ F, the compound having such -COF, perfluoroalkyl group lubricity and non-tacky In addition, the polar group serves to improve the adhesion between the heat resistant resin and the fluorine compound. Here, a fluorine-based compound in which the polar group is located at the terminal of the molecule is preferable because of excellent adhesion, and one or two or more of these polar groups can be contained in one molecule of the fluorine-based compound. Which may also be present). Note that −NCO
If a fluorine-containing compound having a group and a fluorine-containing compound having an -OH group are used in combination, the adhesion between the heat-resistant resin and the fluorine-containing compound is further improved. It is also possible to use a fluorine compound together. Specific examples of such a fluorine-based compound are as follows,
These can be used alone or in appropriate combination. That is, C ₃ F ₇ O (C ₃ F ₆ O) ₃ COF, C ₆ F ₁₃ COOH, C ₆ F ₁₃ C ₂ H ₄ OCOCH ₂ SH, C ₈ F ₁₇ C ₂ H ₄ OH, C ₈ F ₁₇ C ₂ H ₄ SH, C ₈ F ₁₇ SO ₂ F, F ₁₀ F ₂₁ SO ₃ H, C ₁₀ F ₂₁ CONHC ₂ H ₄ OH, etc., and a method in which a fluorine-based compound whose polar group is a hydroxyl group and various polyfluoroalkyl group-free isocyanates are used together May be adopted.

In order to form a thin film of a fluorine compound for imparting lubricity and non-adhesiveness to a copying machine separation claw, the viscosity of the fluorine compound as it is is too high, so that it is dissolved or dispersed in an organic solvent and sprayed, for example. The treatment may be carried out by an appropriate method such as a method or a dipping method, but the dipping method is preferable because the treatment liquid is extremely wasted. In addition,
Examples of the organic solvent include ketones such as acetone and methyl ethyl ketone, esters such as methyl acetate, methyl acetate and isoamyl acetate, ethers such as diethyl ether and dioxane, methyl chloroform, trichloroethylene, tetrachloroethylene, tetralachlorodifluoroethane, 1,1. , 2-trichloro-1,2,2-trifluoroethane (CFC 113) and the like, and one or a mixture of two or more halogenated hydrocarbons. The concentration of the fluorine-based compound dissolved in these organic solvents is not particularly limited, but is preferably about 0.3 to 10% by weight in terms of cost, and when a particularly effective thin film is to be obtained. It is preferably about 0.5 to 3% by weight. Furthermore, after forming a thin film, it is dried, and the surface is polished with a soft cloth or tissue paper to make the slightly cloudy surface state glossy, but such an operation removes excess fluorine compounds. It is effective in doing. Since the film of the fluorine-based compound formed on the surface of the separating claw in this way is very thin, it is difficult to measure the film thickness. Since the monomolecular layer of the fluorine compound applied to the present invention is considered to have a thickness of about 40 Å, it is estimated that this film has a film thickness close to that, and at most 1 μm or less. A film that is too thick contains an excess of fluorine-based compounds, and as a result has many free reactive groups that are not involved in the binding with the separating nail base material resin, it is required for the separating nail for a copying machine of the present invention. It adversely affects the lubricity and non-adhesiveness.

In order to remove the organic solvent, the above method is applied to the separation nail base material resin, that is, the fluorine compound is dissolved or dispersed in an organic solvent at an appropriate concentration, and a film is formed by an appropriate treatment method such as a dipping method. For example, it is dried in a hot air (around 50 ° C.) drying oven or the like. It is of course possible to carry out the treatment at a higher temperature after such drying or also for drying, and it is preferable to change the method of increasing the affinity between the polar group of the fluorine-based compound and the separating nail base material resin. For example, the aromatic polyamide-imide resin TORLON manufactured by Amoco Corp. of the United States is injection-molded onto the surface of a base material in the shape of a separating claw to apply a fluorine-based compound solution by a dipping method to form 250-27.
The method is such that the heat treatment is carried out at a high temperature of 0 ° C. (that is, a high temperature at which the base material resin and the fluorine-based compound do not undergo thermal deformation or thermal decomposition) for an appropriate time.

〔Example〕

Examples and comparative examples will be shown below, but the mixing ratio of the raw materials is all wt%.

Examples 1-3: Graphite 10%, polyetherimide resin (US General Electric Co .; ULTEM1000) 30% and aromatic polyamideimide resin (US Amoco: TORL)
ON 4000T) 60% was mixed with a Henschel mixer, and then kneaded and extruded using a twin-screw melt extruder, and the extruded strand was cut into pellets. The pellets thus obtained were injection-molded to prepare molded articles having the shape of separating claws and test pieces for a friction test. Further, the following three types were selected as fluorine-based compounds, and in each of Examples 1 to 3, a CFC 113 solution containing 1.5% of the fluorine-based compound was prepared, and the molded article and the test piece were dipped in this solution. , Take out after dipping 26
Drying and heat treatment were performed at 0 ° C. for 24 hours.

Fluorine-based compound: In Example 1, C ₈ F ₁₇ OCONH (CH ₂ ) ₆ NCO In Example 2, In Example 3, C ₈ F ₁₇ C ₂ H ₄ OH Note that the obtained molded product and test piece were evaluated for lubricity, non-adhesiveness, functionality as a separating nail material, and the like. The method of each evaluation is as follows. The results obtained are summarized in Table 1.

(1) Lubricity: Using a thrust type friction tester, a bearing steel (SUJ2) was tested under the conditions of a load of 1 kg / cm ² and a speed of 1 cm / sec.

(2) Non-adhesiveness: The contact angle for water and acetic acid was determined using a goniometer-type contact angle tester manufactured by Elma Optical Co., Ltd. using the separating nail as a test piece.

(3) Functionality as a separating claw material: A dry copying machine Z-60 type manufactured by Sharp Corporation was used, and a test piece having the same shape as the separating claw of the same type was attached at a fixed position, and 50,000 copy sheets of A4 size were continuously printed. Pass the paper, repeat 50,000 times,
Fusing roller The number of copies before the occurrence of poor separation of paper (paper jam), the presence or absence of toner image contamination due to nail marks, the amount of toner adhered to the separation nail (not adhered or a very small amount (marked with ◎), A relatively small amount (○), a small amount (Δ), and a large amount (×) 4
Evaluation]. After the paper passing test, the toner attached to the separating claw was wiped off with ethyl alcohol, and then the contact angle with water and acetic acid was measured.

Comparative Example 1: A test piece was prepared in the same manner as in Examples 1 to 3 except that the coating film of the fluorine-based compound was not provided on the surface of the separating nail, and the same measurement was performed. The results obtained are also shown in Table 1. As is clear from Table 1, the separating claws of Examples 1 to 3 are very excellent in both lubricity and non-adhesiveness,
The practical function of the copying machine was also satisfactory, and the contact angle after the paper passing test showed the same large value as before the test.
There was a large difference from the contact angle of Comparative Example 1. This is completely different from the case of Comparative Example 1 on the surface of the separating nails of Examples 1 to 3, and even after the test, the film of the fluorine-based compound was strictly present, and the good adhesion strength and resistance of the film were obtained. Shows wear resistance.

Examples 4 to 9: As a heat-resistant resin, an aromatic polyamide-imide resin [TORLON 4203L (Titanium dioxide 3%, tetrafluoroethylene resin 0.5% mixed) manufactured by Amoco USA, Inc.] was used in Example 4. Is an aromatic polyaromatic polyamide resin (TORLON 4301 Graphite 12%, tetrafluoroethylene resin 3% mixed, manufactured by Amoco, USA), and in Example 6, polyphenylene sulfide resin [RE 101 J manufactured by Asahi Glass Co., Ltd.
A], in Example 7, polyphenylene sulfide resin [PFG 1530 JA manufactured by the same company (tetrafluoroethylene resin 15
%, Mixed with 30% of glass fiber)], and in Example 8 an aromatic polyetherketone resin [PEEK-150P manufactured by British ICE Co., Ltd. and potassium titanate whiskers (Tesmo D101 manufactured by Otsuka Chemical Co., Ltd. at 7: 3). Melt blend],
In Example 9, aromatic polyimide resin [VESPEL-SP1 manufactured by Dupont, USA] was used, and the molding method was injection molding in the same manner as in Example 1 because of the thermal properties of each resin. However, in Examples 4 and 5, the obtained molded product was further heat-treated at 260 ° C. for 24 hours, and in Example 9, the test piece was machined from a round bar, and the molded product had the same foot as in Example 1. The same operation as in Example 1 was carried out except that the heat treatment was carried out in a hot air drying oven at 50 ° C. after the application of the base compound to prepare separation nails whose surface was coated with the fluorine base compound. The same measurement as in Examples 1 to 3 was performed. The results obtained are summarized in Table 2. As is clear from Table 2, the separation claws in Examples 4 to 9 were also used in Example 1.
As in the case of No. 3 above, lubricity, non-adhesiveness, and practical functions are all very good, and the adhesion strength and abrasion resistance of the coating are satisfactory even when the contact angle value after passing the paper is seen. I was able to do it.

Comparative Examples 2 to 8: As a heat resistant resin, in Comparative Examples 2, 3 and 8, the same aromatic polyamide resin as in Example 4 [TO manufactured by Amoco, Inc. of the United States]
RLON 4203L], in Comparative Example 4 an aromatic polyamide-imide resin [TORLON 4327 (12% Graphite, 8% tetrafluoroethylene resin mixed) manufactured by Amoco, USA], Comparative Example 5
To The same polyphenylene sulfide resin as in Example 6 [RE 101 JA manufactured by Asahi Glass Co., Ltd.] and Comparative Example 6 in which the same polyphenylene sulfide resin as Example 7 [RF manufactured by the same company]
G 1530 JA], and in Comparative Example 7, the same aromatic polyetherketone resin as in Example 8 (manufactured by UK IC Corp.)
In PEEK-150P, potassium titanate whiskers (Temos D101A manufactured by Otsuka Chemical Co., Ltd. melt-blended at 7: 3) were used, and these resins were injection-molded in the same manner as in Example 1, and in Comparative Rows 2, 3, 4 and 8. After molding 260
Heat treatment was performed at ℃ for 24 hours, and Comparative Examples 3 and 5
Fluorine resin-containing resin enamel [Polyflon tough coat enamel TC7105GN and TC manufactured by Daikin Industries, Ltd.
7409BK] is evenly coated with a suction spray gun to a film thickness of about 30 μm, and this is dried at 100 ° C. for 30 minutes,
Further, Comparative Example 3 was heat-treated at 250 ° C. for 30 minutes, and Comparative Example 5 was heat-treated at 180 ° C. for 30 minutes. In Comparative Example 8, after heat treatment, a polyfluoroalkyl ether polymer containing no polar group [FO manufactured by Ikoku Montedison Co., Ltd.
MBLIN-Z25 (viscosity 250 cst at 20 ° C.) was dissolved in Freon 113 to a concentration of 1.5%, the separation claws were dipped, then taken out and dried (50 ° C.). The same test as in 1 was conducted, and the results obtained are summarized in Table 3. As is clear from Table 3, The nails of Comparative Examples 2, 4, 6 and 7 in which a coating was not formed on the surface of the separating nail were poor in lubricity and non-adhesiveness, and the practical function was not good. Also, in Comparative Examples 3 and 5 in which a coating was formed on the surface of the separating claw, the tip R was increased by a thick film of 30 μm, and the coating had insufficient lubricity and non-adhesiveness to cause separation failure, or a claw mark was left. The amount of toner has entered or the amount of toner attached has increased. Further, in the nail of Comparative Example 8 in which a thin film made of a polyfluoroalkyl ether polymer having no polar group was formed, the lubricity and non-adhesiveness before the test were very excellent, but the separation was poor during the paper passing test, Practical functional obstacles such as nail marks and toner adhesion amount appeared, and the contact angle (both water and acetic acid) after the paper passing test was greatly reduced, and it was the same value as the uncoated nail. . This is considered to be due to the peeling of the coating film during the test due to the lack of adhesion strength to the nail base material.

〔effect〕

As is clear from the above, the separating claw for a copying machine of the present invention is excellent in both lubricity and non-adhesiveness, and the conventional coating technology is improved by improving the adhesion strength between the coating and the base material and thinning the coating. The present invention can sufficiently withstand long-term continuous use without causing separation defects or paper jam due to the increase of the tip R of the tip of the separation claw, which is a drawback of 1., and without impairing thermal conductivity and electrical conductivity. Therefore, it can be said that the significance of the present invention is extremely great.

Claims (1)

[Claims] 1. A surface layer of at least a tip portion of a heat-resistant resin separating claw for peeling a fixing paper from a fixing roller has 2 to 2 carbon atoms.
Separation for a copying machine, characterized in that it is covered with a fluorine-based compound having a polyfluoroalkyl group of 0 and a polar group having a high affinity with the surface of the base material resin of the separating claw. nail.