JPH0820829B2 - Cleaning blade - Google Patents

Description

The present invention relates to a cleaning blade for cleaning and removing residual toner and the like on the surface of a photoconductor by rubbing the surface of the photoconductor or the surface of a fixing roller of an electrophotographic copying machine.

[Conventional technology]

In electrophotographic copying machines, a so-called cleaning blade method has been put into practical use as one of cleaning methods for photoconductors, in which an elastic rubber blade such as urethane rubber is brought into contact with the electrophotographic photoconductor to remove and clean residual toner on the photoconductor. There is. However, in this method, since the blade is brought into physical contact with the surface of the moving photoconductor, the cleaning effect is significantly reduced due to rapid and nonuniform wear of the tip of the blade due to frictional action with the surface of the photoconductor. There are drawbacks. If such uneven wear of the blade progresses, a ghost image may appear on the recording paper, thread-like streaks may appear, and residual toner may be fused to the surface of the photoconductor to shorten the life of the photoconductor. become.

[Problems to be solved by the invention]

Conventionally, in order to improve such a defect, measures have been taken to reduce the frictional resistance between the surface of the photoconductor and the blade.
For example, externally adding a lubricant substance such as Teflon to the developer, or forming a cleaning blade agent by selecting a smooth material such as Teflon or silicon rubber, or forming a blade material. The idea is to simply fill the inside with silicone oil and a fluorine compound. However, we have not yet found one that exhibits sufficient cleaning effect and durability.

An object of the present invention is to solve the above-mentioned problems, to provide a cleaning blade having low friction properties, excellent wear resistance, and capable of maintaining good cleaning properties stably for a long period of time.

[Means for solving problems]

The above-mentioned object is a cleaning blade having a urethane elastic body as a main component for rubbing the surface of a drum to clean the surface. The cleaning blade comprises a urethane-forming material and fluorine having one or more active hydrogen atoms in one molecule. It is molded by pouring a raw material containing a compound into a mold, and the urethane elastic body is made of urethane containing a reaction product of a urethane-forming material and a fluorine compound having one or more active hydrogens in one molecule. Can be achieved by a cleaning blade characterized by

Preferable examples of the fluorine compound having one or more active hydrogens in one molecule used in the present invention include compounds having hydroxyl group (OH) or amino group (NH ₂ ) as active hydrogen in the molecule. To be

For example, However, the present invention is not limited to this.

The blade according to the present invention contains fluorine atoms in the structure and imparts activity to the blade itself, and thus has low friction and excellent durability.

The urethane elastic material used in the present invention can be used without particular limitation as long as it can be urethane as a result of the reaction, but it is preferable that it finally has a hardness in the range of JIS A scale of 50 to 90 °. . Representative examples of the urethane elastic material are isocyanate and polyol to be polyaddition polymerized, and the reaction of these with a fluorine compound having one or more active hydrogens in one molecule is as described above for the material of the cleaning blade. It may be carried out at any stage as long as it has a different structure.

The fluorine compound having one or more active hydrogens in one molecule is preferably added in an amount of 0.1 to 90% by weight, particularly 1 to 30% by weight, based on the total amount of the cleaning blade raw material.

The cleaning blade of the present invention is preferably a cleaning member formed by joining and molding a supporting portion supporting the cleaning blade through a thermoplastic resin. Generally, the cleaning member has an elastic raw material and a supporting portion supporting the same, using an undercoat adhesive obtained by dissolving a reaction-type chemical substance that is adhesive to the supporting portion and reacts with the liquid elastic raw material in a solvent, This is because they are formed by joining, but the defects that occur at that time can be removed. More specifically, the cleaning member is generally prepared by diluting the undercoat adhesive with a solvent to the adhesive strength required in the molding step and dipping or spraying this on the support, and then the solvent is removed from the coating material by hot air or natural drying. After drying, it is mounted in an injection-integrated mold, and then the cleaning blade material is injected into the mold to be molded. At this time, there are problems such as difficult control of the concentration of the adhesive substance to stabilize the adhesive force, and the risk of ignition and explosion due to the influence on the human body due to solvent volatilization and the retention of solvent. With the above structure, such defects can be eliminated, the bonding state can be stabilized, the adhesiveness and accuracy can be improved, and the manufacturing cost can be reduced.

FIG. 1 shows a cross-sectional view of one embodiment of a cleaning member having a structure having such advantages. This figure shows a cleaning blade 2 in contact with a surface of a photoreceptor or a dielectric as a member to be cleaned, a fixing roller (not shown), a supporting plate 3 for supporting the cleaning blade 2, and a cleaning blade supporting portion 31 of the supporting plate 3. The thermoplastic resin 1 that is provided on the surface in advance and is thermoplastic by the heat of the reaction and firmly adheres the cleaning blade 2 and the support portion 31 is shown.

As an example, when a metal plate was used as the support plate 3, the thermoplastic resin 1 was constituted as a single layer, but a strong adhesion showing an adhesive force of 2500 g with respect to a width of 20 mm was obtained by the polyamide resin, An adhesion of 2000 g was obtained with polyester resin.

In the embodiment shown in the figure, the interface between the two members 2 and 3 is joined with the thermoplastic resin 1 to secure the joining force and the sealing property, but at this time, it is important in the following points. Firstly, the adhesive surface is well wetted, secondly it flows well, and thirdly it solidifies and has a certain strength. As the thermoplastic resin which meets these requirements, urethane type, polyester type, polyamide type, acid vinyl type and the like having a melting point range of 80 to 160 ° C. are suitable. Further, in order to increase the bonding strength, it can be improved by adding a tackifier to the thermoplastic resin. These thermoplastic resins can be used in the form of film or pellet. The film-shaped one is a hot-melt gun or a special dispenser that has means such as a hot roller, hot air blow, hot stamp, hot press, or heating of the adherend, and joins the thermoplastic resin to the holding member in place. To do.

FIG. 2 shows one mode of manufacturing the cleaning member shown in FIG. Reference numeral 3 is a support plate, 1 is a thermoplastic resin, 4 and 5 are molds that are divided into a right mold and a left mold in aa cross section, 6 is a seal buffer fixed to the right mold and the left mold, and 7 is a support. A positioning pin of the plate 3, 8 is a support plate fixing screw, and 9 is a raw material injection space of the cleaning blade of the present invention. In this way, the final mold is formed by the right mold 5 while the support plate 3 to which the thermoplastic resin 1 is bonded is fixed to the left mold 4. When the mold is kept warm at a molding temperature of 60 to 140 ° C, the thermoplastic resin becomes softened or melted, energy is lowered on the critical surface and wettability is improved, and the space 9 surrounding the resin 1 formed by the mold is improved. When the reactive cleaning blade material is injected, the materials are firmly bonded and the cleaning member shown in FIG. 1 is molded.

FIG. 3 shows a structure for further increasing the adhesive strength of the thermoplastic resin. In this embodiment, the thermoplastic resin itself has a two-layer structure, the resin 12 on the cleaning blade side, which is an elastic body, has the same or similar material structure as the cleaning blade raw material, and the resin on the support plate 3 side with respect to the support plate 3. The function is separated by using a material having high adhesive strength. According to this aspect, even if the cleaning blade 2 is pulled from the support plate 3, the cleaning blade 2 does not peel off and extremely strong adhesion can be achieved, which is a more preferable configuration for using the cleaning blade of the present invention.

FIG. 5 is a diagram for explaining another embodiment of the cleaning member using the cleaning blade of the present invention.

FIG. 5 shows that the thermoplastic resin 1 has a larger adhesion area to the support plate 3 than the above embodiment (length M).
A larger length N of adhesive has been achieved), and this increase (NM) 13 is used as part of the mold that forms the injection mold space for the cleaning blade raw material. The increased portion 31 is pinched by the right die 5 and the left die 4 in FIG. 2 and seals the space 9 to function as a seal material. In this way, by making the joint area between the support plate and the thermoplastic resin larger than the joint area between the cleaning blade and the thermoplastic resin, the seal cushioning mechanism 6 which has been worked in the mold until now is heated on the support member side. It can be replaced with a plastic resin,
There are advantages such as durability of the mold, low cost, and elimination of seal leakage to the cleaning blade raw material.

FIG. 6 shows still another cleaning member using the cleaning blade of the present invention. FIG. 4 is a diagram showing a manufacturing example thereof. Briefly, a cleaning member including the features of FIGS. 3 and 5 and a method of manufacturing the same are shown.
In the following description, the above description will be omitted.
In the figure, E is a portion corresponding to the difference (N−M) 13 and shows a portion where the above-mentioned resin 11 is extended. Resin 12
Is the same length as the above, and the support plate on which the thermoplastic resins 11 and 12 are previously provided is fixed to the left mold 41 as described above, the portion E of the resin 11 abuts the protrusion D of the mold, The opposite side of E comes into contact with the protrusion D of the right mold 51 by mounting the right mold 51,
The lower gap of the space 9 is sealed by the resin 11. After that, when the mold temperature is raised to the molding temperature, as shown in FIG.
The thermoplastic portion is melted in the D portion of the molds 41 and 51 of (b),
Molds 4 and 5 shown in Fig. 1 in the form of plastic deformation like part E.
A seal cushioning effect similar to that of the inside seal cushioning portion 6 can be provided, and by injecting the cleaning blade material into the seal cushioning portion 6 as in the above embodiment, a molded product as shown in FIG. 6 is obtained.

In the manufacturing method of FIG. 2, it is necessary to remove the wet cleaning blade raw material as a post-treatment, but this can be prevented in the above mode, and moreover, the cleaning member itself can be in a strongly adhered state, so that it is highly durable. The cleaning effect can be stabilized.

Although the cleaning member having a preferable structure using the cleaning blade of the present invention has been described above, it is needless to say that it can be used as another structure.

For example, one having a structure in which a cleaning member and a support member are bonded together via an adhesive, one having a structure in which a cleaning member is sandwiched between support members having grooves, or one in which two cleaning members are mechanically sandwiched and fixed. Can be given.

〔Example〕

 Hereinafter, examples will be described.

Example 1 The components used are as follows.

Ingredients (parts by weight) -Condensed polyester polyol of ethylene glycol and adipic acid 100 (Molecular weight 2000) -Diphenylmethane diisocyanate 42.0-1, 4-butadiol 6.5-Trimethylolpropane 3.6-Perfluorononyl hydroxyhexyl ether 7.1 Diphenylmethane on the dehydrated polyester Diisocyanate is mixed and reacted at 80 ° C for 2 hours, and the resulting prepolymer is mixed with 1,4-butadiol, trimethylolpropane, and perfluorononyl hydroxyhexyl ether, which are curing agents, and heat-cured to obtain JIS A scale 62 The cleaning blade according to the present invention was molded at a temperature of 90 °.

Example 2 The components used are as follows.

Ingredients (parts by weight) -Condensed polyester polyol of ethylene glycol and adipic acid 100 (molecular weight 2000) -Diphenylmethane diisocyanate 38.0-1, 4-butadiol 5.9-Trimethylol propane 3.2-Fluoropolymer Trade name Lumiflon 602 Asahi Glass Co., Ltd. 2.3 Lumiflon, 1,4-butadiol, and trimethylolpropane were mixed with the prepolymer synthesized in the same manner as in Example 1 and heat-cured to form a cleaning blade of JIS A scale having a hardness of 80 ° according to the present invention. .

Comparative Example The components used are as follows.

Components (parts by weight) -Condensed polyester polyol of ethylene glycol and adipic acid 100 (molecular weight 2000) -Diphenylmethane diisocyanate 39.5-1, 4-butadiol 6.3-Trimethylolpropane 3.4 Diphenylmethane diisocyanate was mixed with the dehydrated polyester at 80 ° C and 2 After reacting for a period of time, the prepolymer produced is mixed with a curing agent such as 1,4-butadiol and trimethylolpropane and heat-cured.
A scale 65 ° cleaning blade was molded.

(Evaluation) The cleaning blade obtained as described above was evaluated for cleaning property, durability by an electrophotographic copying machine using an amorphous silicon photoconductor, and dynamic friction coefficient by a friction tester. The results are shown in Table 1.

The cleaning blades formed in Examples 1 and 2 showed no wear at the tip of the blade even after passing 300,000 sheets, and the cleaning performance maintained the initial performance without any problem. on the other hand,
The cleaning property of the comparative example in which a fluorine compound having one or more active hydrogen atoms in one molecule was not used was deteriorated.

Example 3 A cleaning member was produced as follows using the cleaning blade of the present invention.

As shown in FIG. 7, a film-shaped thermoplastic resin such as thermoplastic polyamide (Diabond PA-50) was thermocompression-bonded to the holding member by hot pressing at 130 ° C. and 0.5 Kg / cm ² . Attach this to the injection molding die as shown in Fig. 2, and
When the mold temperature became stable at 0 ° C., the blade material of Example 1 was injected from a predetermined injection port of the mold to integrally mold it. After 40 minutes, the pieces were taken out from the mold, heated at about 120 ° C. for 4 hours, and then left for one week at room temperature for aging. Thereafter, as shown in FIG. 8, the BB portion and the CC portion were separately fixed and pulled in the opposite directions, and the joining force of the joining portion at that time was measured. As a result, as shown in Table 2, the bonding strength was higher than that without the thermoplastic resin.

Example 4 A cleaning member was produced as follows using the cleaning blade of the present invention.

The blade raw material used is the blade material described in Example 1.

Resin 12 thermoplastic polyurethane (Nippon Matai UH204)
And resin 11 is a thermoplastic polyester (Nippon Matai PH41
3), and these were thermocompressed with a hot press at 130 ° C. under 0.5 kg / cm ² to form a member as shown in FIG. 3, which was manufactured as shown in FIG. 2, and then joined as shown in FIG. When the force was measured, the adhesive force until the elastic body was broken was shown (Table 2).

〔The invention's effect〕

The cleaning blade of the present invention is a fluorine compound having one or more active hydrogen atoms in one molecule that has reacted with a urethane material, and therefore has low friction properties, excellent wear resistance, and maintains good cleaning properties for a long period of time. it can.

Further, not only is it filled in the urethane material because it has active hydrogen, but it also reacts with the isocyanate groups and has a chemical bond, so there is no phenomenon of blooming on the surface during use of the blade. It is durable.

[Brief description of drawings]

1 and 6 are explanatory views of an embodiment of a cleaning member, FIG. 2 is a schematic diagram for explaining a manufacturing method of the cleaning member of FIG. 1, and FIGS. 3, 5, and 7 are cleaning members, respectively. 4A and 4B are explanatory views of an embodiment for explaining a method for manufacturing a cleaning member, and FIG. 8 is a view for explaining a measurement for comparing the adhesive force of the cleaning member. FIG. 1, 11, 12 are thermoplastic resins, 2 are cleaning blades, and 3 are support plates.

Claims (1)

[Claims] 1. A cleaning blade comprising a urethane elastic body as a main component, which is rubbed against the surface of a drum to clean the surface. The cleaning blade comprises a urethane-forming material and fluorine having one or more active hydrogen atoms in one molecule. It is made by pouring a raw material containing a compound into a mold,
A cleaning blade characterized in that the urethane elastic body is made of urethane containing a reaction product of a urethane-forming material and a fluorine compound having one or more active hydrogens in one molecule.