JPH07290601A - Manufacture of cleaning blade - Google Patents

Abstract

PURPOSE:To provide a method capable of simply manufacturing a cleaning blade with a low frictional layer without employing a special process or apparatus. CONSTITUTION:The manufacture of a cleaning blade is such that a cleaning blade mold having a releasing agent-applied layer formed on the molding surface and a liquid cleaning blade molding composite consisting mainly of urethane rubber polymer and curing agent are prepared, and the liquid cleaning blade molding composite is poured and subsequently cured into the cleaning blade mold, and then the cured composite is removed from the mold. For such releasing agent, a substance is used which has a reaction element that is reactive to urethane rubber and slippage element contained therein.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a cleaning blade used for removing residual toner on the surface of a photosensitive drum of an electrophotographic copying machine or the like.

[0002]

2. Description of the Related Art In an electrophotographic copying machine, printer or the like adopting an electrophotographic copying method, generally, a cleaning device 3b shown in FIGS. 5A and 5B is used to remove residual toner on the surface of a photosensitive drum. It is done by physical removal. FIG. 5A is a perspective view showing the configuration of the cleaning device, and FIG. 5B is a sectional view thereof. In these drawings, the cleaning device 3b is configured such that a cleaning blade 1 formed of a rubber elastic body or the like is attached to one end of a plate-shaped holding material 2. And
As shown in FIG. 6A, this cleaning device 3b
Is fixed to a base (not shown) by a plate-shaped holding material 2 inside the electrophotographic copying machine, and is obliquely arranged so that the tip corner portion of the cleaning blade 1 is pressed against the surface of the photosensitive drum 4. ing. When the photosensitive drum 4 rotates in the direction of the arrow in this state, the residual toner 5 is scraped off and the surface of the photosensitive drum 4 is cleaned.

Urethane rubber is generally used as the rubber elastic body of the cleaning blade forming material. This urethane rubber cleaning blade is usually manufactured by the prepolymer method as follows. That is, first, a cleaning blade molding die in which a mold release agent coating layer is formed on the molding surface is prepared. The release agent coating layer is for easily releasing the urethane rubber cured into a predetermined cleaning blade shape from the molding die. Next, a liquid cleaning blade molding composition containing a prepolymer obtained by partially polymerizing a polyisocyanate and a polyol (hereinafter referred to as "prepolymer for urethane rubber") and a curing agent as main components is injected into the above mold. It is produced by subjecting this to a curing reaction and then demolding this cured product.

[0004]

The urethane rubber cleaning blade has the advantage that it has a long life due to its excellent wear resistance and the like, but it may be reversed along with the rotation of the photosensitive drum at the start of copying. is there. That is, the friction between the urethane rubber cleaning blade and the surface of the photosensitive drum is large, but after the copying is started, the toner intervenes between them, so the friction is reduced and the cleaning blade Inversion does not occur. However, when there is no toner such as when copying is started, as shown in FIG. 6B, the cleaning blade 1 is reversed as the photosensitive drum 4 rotates. Thus, once the cleaning blade 1 is reversed,
Even if the contact with the photosensitive drum 4 becomes insufficient and the copying starts and the toner remains on the surface of the photosensitive drum 4, the residual toner cannot be completely scraped off.

In order to solve the problem of the reversal of the cleaning blade, a cleaning blade having a low friction layer formed on a part of the surface thereof has been proposed and partially implemented (JP-A-4-260084). In this cleaning blade, a low friction layer forming agent, which is a mixture of a slipperiness-imparting agent such as fluorinated graphite and an adhesive such as nylon resin, is applied to the contact portion of the cleaning blade of the cleaning blade by a dipping method or the like to reduce A friction layer is formed. By doing this, it is possible to reduce the friction between the photosensitive drum and the cleaning blade, and prevent the cleaning blade from being reversed even when toner is not present on the surface of the photosensitive drum such as when copying is started. become. However, to manufacture the cleaning blade having the low friction layer,
In addition to the conventional process, the process of moving the cleaning blade manufactured through the curing and demolding process to the coating work place and the coating process of the low friction layer forming agent are newly required, which increases the manufacturing cost. There is a problem. In addition, the cost of equipment such as a special coating device used for the dipping method or the like is also required.

The present invention has been made in view of the above circumstances, and provides a cleaning blade having a low friction layer,
It is an object of the present invention to provide a manufacturing method of a cleaning blade that can be easily manufactured without using a special process or apparatus.

[0007]

In order to achieve the above object, the present invention provides a mold for a cleaning blade having a mold surface coated with a release agent, a prepolymer for urethane rubber, and a curing agent. A liquid cleaning blade molding composition containing as a main component is prepared, and the liquid cleaning blade molding composition is injected into the cleaning blade molding die to be cured, and then the cured blade is released from the mold by a manufacturing method of a cleaning blade. Therefore, a configuration is used in which the release agent contains a reaction element that reacts with the urethane rubber and a slipping element.

[0008]

The present inventors have conducted a series of studies in order to solve the above conventional problems. In the process of research, if the low-friction layer is formed on the surface of the cleaning blade by using the mold release agent applied to the molding surface of the mold as it is, it is possible to omit or save the steps and materials for providing the low-friction layer. I got the idea that Based on this idea, in testing various types of materials for mold release agents, a special mold release agent containing a reaction element that reacts with urethane rubber and a slippery element was applied to the molding surface of the mold. To form a release agent layer, and a liquid cleaning blade molding composition containing a prepolymer for urethane rubber and the like is injected into the mold and cured, the cleaning blade surface generated in the mold has the above-mentioned release agent. It was found that the mold release agent layer was bonded to the mold, and when the cleaning blade was released from the mold, the mold release agent layer was transferred to the surface of the cleaning blade to form a low friction layer, and the present invention was reached. The cleaning blade provided with the low friction layer composed of the release agent layer does not cause reversal at the start of copying or the like. As described above, according to the present invention, since the release agent layer can be directly used as the low friction layer, it is not necessary to specially provide a coating process or equipment for forming the low friction layer, and a significant cost reduction can be achieved. Can be realized.

Next, the present invention will be described in detail.

The manufacturing method of the cleaning blade of the present invention is carried out by using a cleaning blade molding die, a liquid cleaning blade molding composition and a special release agent.

The mold for the cleaning blade is not particularly limited, and a mold used for manufacturing a general cleaning blade is used.

As the liquid cleaning blade molding composition, a composition containing a urethane rubber prepolymer and a curing agent as main components is used.

The urethane rubber prepolymer is obtained by partially polymerizing polyisocyanate and polyol.

Examples of the polyisocyanate include, for example, 4,4'-diphenylmethane diisocyanate (M
DI), isophorone diisocyanate (IPDI),
4,4'-Dicyclohexylmethane diisocyanate (water-added MDI), trimethylhexamethylene diisocyanate (TMHDI), tolylene diisocyanate (TDI), carbodiimide modified MDI, polymethylene phenyl polyisocyanate (PAPI), orthotoluidine diisocyanate (TODI), naphthi Diisocyanate (NDI), xylene diisocyanate (XDI), hexamethylene diisocyanate (HMD
I), paraphenylene diisocyanate (PDI), lysine diisocyanate methyl ester (LDI), dimeryl diisocyanate (DDI) and the like. Among these, it is preferable to use MDI, TODI or the like.

As the polyol to be used together with the above polyisocyanate, polyester adipate, polybutylene adipate, polyhexylene adipate, a polyester polyol such as a copolymer of ethylene adipate and butylene adipate, polycaprolactone, polyoxytetramethylene, etc. Examples thereof include polyether polyols such as glycol and polyoxypropylene glycol. Among them, the molecular weight is 1500-3000
It is preferable to use the above-mentioned one. That is, when it is less than 1500, the physical properties of the resulting urethane rubber tend to be deteriorated, and when it exceeds 3,000, the viscosity of the prepolymer tends to be high and the workability of the cleaning blade molding tends to be deteriorated. Is.

The above-mentioned prepolymer for urethane rubber uses the above polyisocyanate and polyol, for example,
It is prepared as follows. First, the above polyisocyanate and polyol are blended and mixed. Next, this mixture is reacted at a temperature of 80 to 120 ° C. for 30 to 90 minutes. This gives a prepolymer. As this prepolymer, the NCO% calculated by the following formula (12) is preferably set in the range of 10 to 30%. The viscosity of the prepolymer in the NCO% range is as low as 100 to 500 cps (75 ° C.). That is, when the value of NCO% is less than 10%,
The viscosity of the prepolymer may not be sufficiently reduced, and it may be difficult to inject it into the molding die. On the other hand, if it exceeds 30%, the curing reaction becomes non-uniform and the physical properties of the resulting urethane rubber deteriorate. This NCO%
The value of can be adjusted by changing the blending ratio of polyisocyanate and polyol. In addition, in this invention, a viscosity says the viscosity measured based on JISK 7117.

[0017]

[Equation 1]

As a curing agent for the above-mentioned urethane rubber prepolymer, it is preferable to use a low molecular weight polyol having a molecular weight of 300 or less. As such a polyol,
For example, ethylene glycol (EG), diethylene glycol (DEG), propylene glycol (PG), dipropylene glycol (DPG), 1,4-butanediol (14BD), hexanediol (HD), 1,4
-Cyclohexanediol, 1,4-cyclohexanedimethanol, xylene glycol (terephthalyl alcohol), triethylene glycol, trimethylolpropane, glycerin, pentaerythritol and sorbitol.

From the viewpoint of easiness of mixing operation and characteristics of the obtained cleaning blade, a suitable combination of the above prepolymer and the curing agent is a prepolymer comprising MDI and polyester polyol as the above prepolymer, and curing. Examples of the agent include a combination with 1,4-butanediol, trimethylolpropane, and polyester polyol. The optimal combination is a prepolymer composed of MDI and polyethylene adipate as a prepolymer, and a combination of 1,4-butanediol, trimethylolpropane and polyethylene adipate as a curing agent.

Thus, the liquid cleaning blade molding composition used in the present invention is obtained. A catalyst that enhances the curing reaction can be added to this composition.
Examples of such a catalyst include triethylenediamine (TEDA) and DBU-2 ethylhexanoate. These are used alone or in combination of two or more. By blending this catalyst, the molding cycle can be shortened and the manufacturing cost of the cleaning blade can be reduced. The amount of the catalyst blended is preferably 100 to 2000 ppm (weight ratio, the same applies hereinafter) of the entire liquid cleaning blade molding composition, and particularly preferably 500 to 1500 ppm. That is, if the catalyst is blended in a proportion exceeding 2000 ppm, the curing reaction between the prepolymer and the curing agent will be too fast, and injection into the mold may be difficult. Further, even if the catalyst is added in an amount of less than 100 ppm, the curing reaction may not be effectively enhanced.

Next, the special release agent which is a characteristic constitution of the present invention will be explained. This special release agent contains both an element that reacts with the urethane rubber and an element that imparts slipperiness. Examples of such agents include a curing agent obtained by modifying the molecular end of a fluorine oligomer or silicone oligomer with a functional group having active hydrogen,
Examples include acrylic oligomers and polyfluoroethers.

Suitable examples of the curing agent obtained by modifying the molecular end of the above fluorine oligomer or silicone oligomer with a functional group having active hydrogen are those represented by the following general formulas (1) and (2). can give. In these curing agents, hydroxyl groups at the ends of the main chain are elements that react with urethane rubber, and fluorine atoms and silicon atoms in the main chain are elements that impart slipperiness.

[0023]

[Chemical 1]

[0024]

[Chemical 2]

Preferable examples of the acrylic oligomer include those represented by the following general formulas (3) and (4). In this acrylic oligomer, a fluorine atom or a silicon atom is an element that imparts slipperiness, and a hydroxyl group at the end of the main chain or an acryloyl group at the side chain is an element that reacts with the urethane rubber.

[0026]

[Chemical 3]

[0027]

[Chemical 4]

As a preferred example of the above polyfluoroether, the one represented by the following general formula (5) can be mentioned. In this polyfluoroether, fluorine in the main chain is an element that imparts slipperiness, and a carboxyl group,
Hydroxyl and isocyanate groups are elements that react with urethane rubber.

[0029]

[Chemical 5]

Among these release agents, it is preferable to use a fluorine-containing type from the viewpoints of coating properties, durability of the low friction layer, and slipperiness. Particularly preferably,
It is a polyfluoroether.

These release agents are usually in liquid form and used as they are, but they may be dissolved in a solvent and used as a release agent coating solution. Examples of the solvent include alcohols such as methanol, ethanol and isopropyl alcohol, hydrocarbons such as methyl ethyl ketone and toluene, tetrahydrofuran (THF), N, N-.
Examples thereof include chlorinated solvents such as dimethylformamide (DMF), N, N-dimethylacetamide (DMAC), and methylene chloride. The release agent has a viscosity of 1000c.
It is preferred to use ones of less than ps, preferably less than 100 cps. That is, the viscosity of the release agent is 10
This is because if it is more than 00 cps, the coating work may become difficult.

The manufacturing method of the cleaning blade of the present invention is carried out as follows, for example, by the prepolymer method using the above materials and the cleaning blade molding die. First, a cleaning blade molding die 6 (mold temperature 60 to 150 ° C.) as shown in FIG. 3A is prepared. The molding die 6 has a molding die portion 6 having a molding space 7.
It is composed of a and a molding die portion 6b. Then, as shown in the figure, one end of the plate-shaped holding material 2 has the molding space 7
Place it so that it is located at. On the other hand, the release agent is applied to the molding surface of the molding space 7 by a spray method or the like to form a coating layer. The thickness of the coating layer at this time is usually less than 10 μm, preferably, for reasons such as dimensional accuracy and durability.
It is set in the range of 1 to 5 μm. FIG. 3B is an enlarged cross-sectional view of the molding surface X. 12a is a coating layer formed by coating a release agent. Separately from this, a prepolymer for urethane rubber, a curing agent, a catalyst and the like are mixed to prepare a liquid cleaning blade molding composition. Next, the liquid cleaning blade molding composition is poured into a molding die having a mold release agent coating layer formed on the molding surface to be cured by reaction, and the cured product is taken out of the molding die. During this demolding, the release agent coating layer 12a is transferred to the surface of the cured product (urethane rubber) to form a low friction layer. In this way, the cleaning blade 1 having the low friction layer 12 formed on the surface of the urethane rubber 11 as shown in FIG. 1 can be prepared.

As described above, in the present invention, the release agent layer is
At the same time, it becomes a low friction layer. Therefore, according to the present invention, it is possible to manufacture a cleaning blade having a low friction layer by using the same process and the same equipment as those of the conventional cleaning blade manufacturing method. This is the greatest feature of this invention.

In the cleaning blade shown in FIG.
As shown in, the low friction layer 12 may be formed via the adhesive layer 13. By interposing the adhesive layer 13, the low friction layer 12 and the urethane rubber 11 are firmly bonded to each other, and the occurrence of peeling of the low friction layer 12 and the like can be prevented.

Examples of the adhesive which is a material for forming the adhesive layer include a rubber adhesive such as chloroprene, a silane coupling agent, an epoxy resin, an acrylic adhesive, and a urethane adhesive. Of these, acrylic adhesives are preferable.

Then, a release agent may be applied to form a coating layer, and the adhesive may be applied onto the layer of the coating layer to form an adhesive layer. Is preferably formed. That is, among the above adhesives, an adhesive that is incompatible with the release agent (such as an acrylic adhesive)
Is used. The mixing ratio (weight ratio) at this time is not particularly limited, but a release agent / adhesive agent = 9/1 to 1
/ 9, preferably release agent / adhesive = 9/1 to 5/5. When the mixed coating liquid is applied to the molding surface of the molding die, the mixed coating liquid 14 is separated into two layers to form a release agent coating layer 12a and an adhesive layer 13, as shown in FIG. To be done. According to this method, the coating of the molding surface of the molding die can be performed in one step.

[0037]

As described above, the cleaning blade manufacturing method of the present invention uses the special release agent containing the reaction element that reacts with the urethane rubber and the slippery element, and the release agent formed on the mold surface. During the molding process, the template layer is transferred directly to the surface of the urethane rubber cleaning blade to form a low friction layer. Therefore, the cleaning blade manufacturing method of the present invention does not require a special low friction layer forming step such as a dipping step, and does not require a moving operation for moving a semi-finished product for each step. Will be simplified. Moreover, since the cleaning blade manufacturing method of the present invention does not require a special coating device or the like, the facility cost can be reduced. Furthermore, in the method for producing a cleaning blade of the present invention, if a coating liquid using the above-mentioned mold release agent and an adhesive that is incompatible with this mold release agent is applied to the molding surface of the above-mentioned molding die, the adhesive layer forming step is performed. It becomes possible to form the low-friction layer through the adhesive layer without providing it. Thus, the manufacturing method of the cleaning blade of the present invention has the same number of steps as the conventional manufacturing method, and does not require a special device. Therefore, it is possible to manufacture at low cost a cleaning blade that does not turn over due to the rotation of the photosensitive drum.

Next, examples will be described.

First, prior to the examples, release agents a to e represented by the following general formulas (6) to (10) were prepared.

[Release agent a]

[Chemical 6]

[Release agent b]

[Chemical 7]

[Release agent c]

[Chemical 8]

[Release agent d]

[Chemical 9]

[Release agent e]

[Chemical 10]

[0045]

Examples 1 to 5 The release agent was applied to the molding surface of the cleaning blade mold to form a coating layer having a thickness of 5 μm. On the other hand, the materials shown in Table 1 below were mixed in the proportions shown in the same table to prepare a liquid cleaning blade molding composition. This composition was poured into the above mold and heat-treated at 130 ° C. Then, the cured product was removed from the mold to prepare a cleaning blade having a low friction layer.

[Comparative Example] The materials shown in Table 1 below were blended in the proportions shown in the same table except that the release agent was not used.
A cleaning blade was prepared in the same manner as in the above example.

[0047]

[Table 1]

Example products 1 to 5 thus obtained,
For the cleaning blade of the comparative example, the friction coefficient,
The surface roughness was evaluated. The results are shown in Table 2 below.
The above characteristics were measured as follows.

[Friction Coefficient] The friction coefficient was measured using the apparatus shown in FIG. That is, the cleaning blade 1 having the plate-shaped holding material 2 at one end was prepared. Then, the other end corner portion of the cleaning blade 1 was pressed against the plate-shaped polycarbonate 7 arranged on the support 8. The pressure contact load (W) was 20 g / cm, and the direction of the load was the plate-shaped polycarbonate 7
Is the vertical direction (arrow X direction). Further, the stress sensor 9 was connected to the plate-shaped holding material. In this state, the support base is run in the direction of the arrow Y at a constant speed, and the stress (F) measured by the stress sensor 9 at this time and the load (W) are given by the following formula (11). Friction coefficient (μ
s) was calculated. As the stress (F), the stress at peak 10 in the curve diagram shown in FIG. 8 was used. The contact angles of the cleaning blade 1 with the plate-shaped polycarbonate 7 are shown in Table 2 below.

Friction coefficient (μs) = F / W (11)

[Surface Roughness] The surface roughness was measured using a contour shape measuring machine (Surfcom 550A, manufactured by Tokyo Seimitsu Co., Ltd.).

[0052]

[Table 2]

From Table 2 above, the cleaning blades of all the examples had low friction coefficients and good surface roughness. From this, it can be seen that the cleaning blade of the example product has excellent slipperiness. On the other hand, the cleaning blade of the comparative example in which the low friction layer was not formed had a large friction coefficient and poor surface roughness. In addition, the cleaning blades of all the above-described examples were easy to manufacture.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a cleaning blade having a low friction layer formed thereon.

FIG. 2 is a cross-sectional view of a cleaning blade in which a low friction layer is formed via an adhesive layer.

FIG. 3A is a cross-sectional view of a cleaning blade molding die, and FIG. 3B is an enlarged cross-sectional view of a molding surface of the cleaning blade molding die.

FIG. 4 is a cross-sectional view showing a state in which a mixed coating liquid of a release agent and an adhesive separates into an adhesive layer and a release agent layer.

FIG. 5A is a perspective view of a conventional cleaning blade, and FIG. 5B is a sectional view thereof.

FIG. 6A is a configuration diagram showing a state in which residual toner on the surface of the photosensitive drum is removed using a cleaning blade, and FIG. 6B is a configuration diagram showing a state in which the cleaning blade is reversed.

FIG. 7 is a configuration diagram of an apparatus for measuring a friction coefficient of a cleaning blade.

FIG. 8 is a curve diagram showing the relationship between stress (F) and time.

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[Procedure amendment]

[Submission date] May 17, 1994

[Procedure Amendment 1]

[Document name to be corrected] Drawing

[Correction target item name] All drawings

[Correction method] Change

[Correction content]

[Figure 1]

[Fig. 2]

[Figure 4]

[Figure 7]

[Figure 3]

[Figure 5]

[Figure 6]

[Figure 8]

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification number Reference number within the agency FI Technical display area G03G 21/10 // B29K 75:00 (72) Inventor Kenichi Ito Komaki City, Aichi Prefecture Kita Toyama Gamitsu 3600 Tokai Rubber Industry Co., Ltd. (72) Inventor Yasuhito Suzuki Akita Prefecture Komaki City Oita Kitayama Yamagitsu 3600 Tokai Rubber Industry Co., Ltd.

Claims (4)

[Claims] 1. A cleaning blade molding die having a coating layer of a release agent formed on a molding surface, and a liquid cleaning blade molding composition containing a urethane rubber prepolymer and a curing agent as main components are prepared. A method of manufacturing a cleaning blade, in which the liquid cleaning blade molding composition is injected into the cleaning blade molding die to cure, and then the cured material is demolded, wherein a reaction element that reacts with urethane rubber as the release agent is used. A method for producing a cleaning blade, characterized in that the cleaning blade contains a slippery element. 2. The method of manufacturing a cleaning blade according to claim 1, wherein the release agent coating layer is formed via an adhesive layer. 3. The cleaning according to claim 1, wherein the releasing agent is a reactive fluorine compound, the element that reacts with the urethane rubber is active hydrogen or an active isocyanate group, and the slipping element is a fluorine atom. How to make a blade. 4. The cleaning according to claim 1, wherein the releasing agent is a reactive silicone compound, the element that reacts with urethane rubber is an active hydrogen or an active isocyanate group, and the slipping element is a silicon atom. How to make a blade.