JPH02289878A - Manufacture of coated roll for printer - Google Patents

Abstract

PURPOSE:To rationalize the formation process of a coating film by thermosetting a metal roll after it is coated with the solution of thermosetting resin wherein solid rubricant is mixed and dispersed. CONSTITUTION:Both edges of the uncoated tube of the metal roll 9 are mold- processed and shaft neck parts are formed. After the tube is pretreated, it is shotblasted and pre-heated, and then coated with the solution, wherein the solid rubricant 11 is mixed to the thermosetting resin 12, in order to form a toner offset preventing layer. By thermosetting this coated resin, such a printing roll is obtained that the metal surface is coated with the thermosetting resin 10 wherein the solid rubricantpowder is dispersed. Thus, without the need of interposing a primer layer, the formation processing of the coating film 10 can be rationalized.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a method for manufacturing a roll for a printing press that is heated and pressurized, such as an electrophotographic copying machine.

[Prior Art] As shown in the outline of FIG. 3, an electrophotographic copying machine, which is the main application of the printing press roll of the present invention, scatters toner on a latent image surface formed on a photosensitive drum l, Attach it to the latent image! jIi image is formed and transferred to copy paper 2. The toner image transferred to the copy paper 2 is fixed by a fixing roll 5 consisting of a heating roll 3 and a pressure roll 4.
The image is fixed by heating and melting it and pressing it onto the copy paper 2.

As shown in FIG. 4, the heating roll 3 has a hollow metal roll 9 as a core material, has an electric heating device B inside the hollow, and has a non-adhesive coating on the surface to prevent toner offset. A covering layer 7 made of a substance is provided. As this non-adhesive substance, silicone rubber, fluororesin such as polytetrafluoroethylene (PTFE), etc. are used.

In the coating layer made of such a non-adhesive substance, for example, metal powder, metal fibers, or fiber chips may be mixed into a rubber elastic body coated on the surface of a metal roll to improve thermal conductivity and electrical conductivity. (Tokuko Sho 61-34
By sequentially laminating a heat-resistant adhesive layer, a heat-resistant oil elastomer layer, a heat-resistant oil adhesive layer, and an anti-offset layer on the surface of a metal roll (No. 146), the anti-offset layer is firmly adhered and the anti-offset layer is prevented from peeling. There is a proposal for a fixing roll (Japanese Patent Publication No. 61-60430) aimed at this.

In addition, the coating method is to apply a primer to the roughened metal roll surface, then apply PFA powder, and then bake it in a furnace, or to apply PFA powder without applying a primer. A method of tightly and firmly adhering a PFA film to a metal roll by baking it and controlling the cooling rate after baking (Japanese Patent Publication No. 61-4126
No. 9) has also been proposed.

On the other hand, the pressure roll can be obtained by having a structure that does not have the heating element of the heating roll, or it is also possible to use the metal roll as it is.

[Question QIJ to be solved by the invention] In conventional printing rolls having a non-adhesive material coating layer, the non-adhesive material has poor adhesion to metal, and in order to overcome this problem, Fig. 2 As shown in the figure, it is necessary to provide a coating layer 7 made of a non-adhesive substance on the surface of the roll 9 made of gold with a heat-resistant and oil-resistant adhesive brimer 8 interposed therebetween. 81-60430) required a complicated manufacturing process as shown in FIG. In addition, in particular, after the brimer treatment, fluororesin powder is applied and the :J resin is fused at 380 to 400°C, so the surface of the fired resin layer has an irregular shape, so it can be made uniform. It was necessary to polish it to make it look like this. Furthermore, in order to ensure the necessary thickness, it was necessary to perform the steps of coating the resin layer and firing the resin layer multiple times.

The present invention aims to eliminate the above-mentioned manufacturing complexity and provide a printing roll that has excellent heat resistance, abrasion resistance, oil resistance, and heat transfer responsiveness, and in which copy paper does not wrap around the roll surface. That is.

[Means for Solving the Problem] In order to solve the above problem, the present inventors conducted various studies and found that this problem could be solved by improving the method of coating metal rolls.

That is, the present invention provides a method for manufacturing rolls for printing presses, in which a metal roll is coated with a thermosetting resin solution in which a solid lubricant is mixed and dispersed, and then the coated surface is machined by heating and curing. This is a method for manufacturing coated rolls for printing presses that can be used without any problems.

Next, an outline of the present invention will be explained according to the flowchart shown in FIG. In the present invention, first, as shown in FIG. 4, the cable tube of a metal roll is formed as it is, or both ends of the metal roll tube are formed to form a shaft neck, and a heat-resistant black paint is applied to this. After that, the roll material is formed by mechanical processing, and after degreasing and cleaning as pre-treatment, shot blasting and preheating are performed to form a toner offset prevention layer.
A solid lubricant (for example, P as a solid lubricant) is added to the hardening resin.
After coating the metal with a solution containing a mixture of TFE or fluororesin powder such as PFA, the coated resin is heated and cured to disperse solid lubricant powder on the metal surface, as shown in Figure 1. This is a method of manufacturing a printing roll coated with a thermosetting resin.

Next, each step will be explained in more detail.

Process of forming the shaft neck by molding both ends of a metal rolled wood pipe By molding both ends, the shaft neck can be made integrally from, for example, aluminum cable pipe, without having to attach it by welding or fitting as in the past. It can be manufactured as a product. In addition, since the profile of the molded part on the inner surface of the roll core village is smooth, the inner surface can be easily degreased and cleaned.

The metal roll used in the present invention is preferably made of aluminum or aluminum alloy, and titanium, steel,
It may also be copper or the like.

Aluminum alloys are classified into AI-Mg-si alloys and JIS-A5052 and JIS-A505 from the viewpoints of strength, heat conductivity, heat resistance, corrosion resistance, and weight reduction.
8 etc. are particularly preferred.

The process of forming the roll material by machining In machining, the resin-coated surface is incorporated into the printing machine without polishing, which is a feature of the present invention, so the roughness and shape of the roll chest surface affect printing performance. Therefore, it is an important element. The surface roughness is Rz 8μ1 or less, preferably 6μ or less.

Degreasing/cleaning process Degreasing/cleaning is an important pretreatment element for fully demonstrating the performance of the resin coating layer. If cutting oil is used during machining, the aluminum surface may be altered in quality, but even in the case of machining without cutting oil, it is preferable to degrease and clean the aluminum immediately after machining.

Deterioration caused by cutting oil should be thoroughly degreased and degreased before coating the resin.
Even if cleaning is performed, there is a possibility that the resin coating layer will not be able to fully demonstrate its performance.

Degreasing and cleaning are preferably carried out by a combination of immersion in a well-known solution such as 1-1-1} dichloroethane and steam, and the effects of degreasing and cleaning can be improved by applying ultrasonic waves to the immersion tank. I can do it.

Shot blasting and preheating process Shot blasting not only cleans the aluminum surface, but also creates an active surface that improves adhesion with resin, and sharpens the uneven shape of the surface to improve the adhesion of resin in the subsequent process. Important for improving sexual performance. As the blasting material, for example, alumina particles #220 are used, and the air pressure is 2 to 3 kgr.
lcm'' conditions are preferred. Desanding after shot blasting is performed while blowing air with a soft brush.

Preheating is preferably carried out at 50 to 80°C, which is preferred in order to prevent dew condensation on the aluminum surface before coating.

Process of coating a solution of a thermosetting resin mixed with a solid lubricant A solution of a thermosetting resin mixed with a solid lubricant is sprayed with, for example, an ordinary spray gun, while stirring constantly. At this time, it is preferable to rotate the aluminum core material and move the spray gun in the axial direction, and to constantly send clean air into the spray chamber to apply back pressure to prevent foreign matter from entering the coating layer. The thickness of the coating layer is adjusted by adjusting the ratio of the amount of the blown air to the mixed solution, the moving speed of the gun, etc., and is determined in accordance with a predetermined standard.

Thermosetting resins must have strong adhesion to metals, as well as heat resistance, abrasion resistance, and oil resistance, and Q-type resins such as polyamide resins, polyamide-imide resins, and epoxy resins are used. Ru.

Solid lubricants are made of PTFE in terms of heat resistance, wear resistance, and oil resistance.
, or fluororesins such as PFA are preferable, and graphite is also preferable depending on the use, and solid lubricants such as metal compounds such as molybdenum disulfide may also be used.

This powder preferably has a particle size of 10 .mu.m or less, and since the surface roughness changes depending on the particle size and spraying conditions, it is preferable to thoroughly adjust the surface roughness. By this adjustment, it is usually possible to obtain a surface roughness that can be used as it is heated and cured. The content of the solid lubricant in the thermosetting adhesive resin is preferably about 5 to 50% by volume.

In the present invention, it is preferable that the thermosetting resin containing the solid lubricant dispersed therein be coated on the gold roll to a thickness of 50 μm or less.

This is because if the thickness of the coating layer exceeds 50 μm, the profile of the surface of the metal roll suitable for a roll for a printing press will be impaired.

Process hardening of the coated resin Heat curing is performed in a tunnel furnace equipped with a heater (for example, a far infrared heater, etc.) at 150 to 250°C for 10 minutes.
It is preferable to heat and cure by holding for a period of ~BO minutes.

The resin coating layer formed in the above process can be applied to the roll surface and then thermally cured to form a smooth coating layer along the fine profile of the roll surface.
As mentioned above, there is no need for subsequent polishing and finishing, so the coating thickness can be made thin, and the roll as a whole has high thermal conductivity, good thermal responsiveness, and small fluctuations in fixing temperature. In addition, since the solid lubricant particles are densely dispersed and the film thickness is thin, permanent compression deformation is small.

Furthermore, since the polishing step is omitted, appropriate unevenness is present in the coating, and the non-stick oil injected between the copy paper and the fixing roll during printing comes into contact with the copy paper through these unevenness. The copy paper can be easily peeled off from the fixing roll. The peeling of the copy paper can be improved by exposing the solid lubricant to the surface by buffing or brushing the coated surface, and in this case, the use of non-viscous oil can be omitted.

[Function] In the method of the present invention, unlike the conventional method, the fluororesin solid lubricant is not fired (sintered) to form a continuous film, but the solid lubricant is dispersed in a heat-cured film as described above. Since the solid lubricant is applied and cured by heating, a film is formed in which the solid lubricant is dispersed in a continuous resin layer.

By changing the film formation method in this way,
Compared to conventional methods, not only can the process of forming a film be greatly streamlined, but also its quality can be significantly improved.

In other words, in the conventional method, it is necessary to apply a primer before applying the fluororesin powder, and the film thickness after one firing of the fluororesin powder is as thin as 10μ■, and it is difficult to obtain the actually necessary film thickness. It was necessary to repeat the process of applying fluororesin and firing.

Moreover, it is difficult to control the temperature when firing fluororesins, and defects often occur on the surface of the resulting film. In addition, the fired surface of the fluororesin has an irregular shape, so it cannot be used as a roll for a printing machine as it is, and a polishing process is essential.

All of these problems in the process of forming a roll coating for a printing press by conventional methods can be solved by the present invention.

[Example] An example will be described based on the drawings. J I formed into a cylindrical shape by extrusion etc. based on the manufacturing method of the present invention shown in FIG.
After the S-A5052 material was drawn at both ends with a die, it was annealed at 400°C to remove strain, and then Okitsumo paint was applied to the inner surface, held at 300°C for 30 minutes, and baked.

After finishing the outer surface of the obtained inner surface coated material by cutting it with a diamond cutting tool, it was degreased and cleaned by dipping in 1-1-1 trichloroethane and steam, and then shot blasting was performed. Shot blasting was performed using #220 alumina particles at an air pressure of 2.5 kgr/el. After that, a rotating nylon brush was used to blast 2.5 kgr/e-2.
After preheating the pretreated roll core stirrer to 60°C, which was brushed while blowing air of It was applied by spraying. The conditions are that the spray pressure is 2.5kgf/c
While rotating the roll core material (60 rpm), the spray gun was moved from top to bottom to prevent the film from dripping. Heat curing was carried out by holding it at 230°C for 20 minutes in a tunnel furnace equipped with a far-infrared heater.
A coated printing press roll was produced.

[Effect of the invention] The present invention has the following effects.

■Since the solid lubricant is dispersed and contained in the thermosetting resin, there is no need to interpose a brimer layer unlike conventional fluororesin coatings, and the coating can be formed with one application and heat curing. , and temperature control is also easy.
The film formation process can be significantly streamlined compared to conventional methods.

(2) Furthermore, the surface of the formed film is smooth and corresponds to the roughness of the base material, making it possible to omit the polishing step.

■The film has excellent wear resistance and can extend the life of the roll.

■Since the film is thin, it has high thermal conductivity and good thermal response, so fluctuations in fixing temperature are small.

■Because the film is thin, permanent compression deformation is small.

■The solid lubricant powder densely covers the surface layer, has an appropriate surface roughness, and prevents the copy paper from wrapping around the regular roll because it retains the non-viscous oil applied to the uneven surface. death,
Printability is improved.

Although the above description has been made with reference to a heat fixing roll, it can also be used as a pressure roll by changing the roll of the present invention to +gW without a heating element. It goes without saying that it can also be used for printing rolls for printers and the like.

[Brief explanation of drawings]

Fig. 1 is a cross-sectional view explaining an embodiment of the present invention, Fig. 2 is a cross-sectional view explaining a conventional example, Fig. 3 is an explanatory view of an electrophotographic copying machine, and Fig. 4 is a cross-sectional view explaining a heating roll. , Figure 5 is
A flowchart explaining the present invention, and FIG. 6 is a flowchart explaining the conventional method. ■...Photosensitive drum, 2...Copy paper, 3...
・Heating roll, 4... Pressure roll, 5... Constant roll, 8... Heating device, 7... Covering layer,
Gradient: Young bride 9: Metal roll, 10: Resin film containing dispersed solid lubricant, IT: Solid lubricant powder, I2: Polyimide resin. Patent Applicant Gunma Aluminum Co., Ltd. Agent Patent Attorney Hide Komatsu Agent Patent Attorney Hiroshi Asahi Agent Patent Attorney Miki Yusai 1 Figure O 2 Figure O 5

Claims (1)

[Claims] A method for manufacturing rolls for printing presses, in which a metal roll is coated with a thermosetting resin solution containing a solid lubricant mixed and dispersed, and then cured by heating.The coated surface can be used without machining. A method for manufacturing coated printing press rolls.