阅读说明：本技术 清洁刮板、处理盒和图像形成装置 (Cleaning blade, process cartridge, and image forming apparatus ) 是由 太野大介 松岛智雄 堤洋介 于 2019-11-06 设计创作，主要内容包括：本发明涉及清洁刮板、处理盒和图像形成装置。所述清洁刮板包含与待清洁部件接触的接触部,所述接触部由含有聚氨酯橡胶的部件构成,所述聚氨酯橡胶通过将至少多元醇组分与多异氰酸酯组分聚合而制造,所述多元醇组分含有相对于整个多元醇组分超过50摩尔％且75摩尔％以下的1,4-丁二醇。100％模量(M100[MPa])与回弹系数(Re[％])之比(M100/Re)为0.25以上。所述回弹系数(Re[％])为25％以上。(The invention relates to a cleaning blade, a process cartridge, and an image forming apparatus. The cleaning blade includes a contact portion that is in contact with a member to be cleaned, the contact portion being composed of a member containing a urethane rubber that is produced by polymerizing at least a polyol component containing more than 50 mol% and 75 mol% or less of 1, 4-butanediol relative to the entire polyol component, and a polyisocyanate component. The ratio (M100/Re) of the 100% modulus (M100 MPa) to the coefficient of restitution (Re [% ]) is 0.25 or more. The coefficient of restitution (Re [% ]) is 25% or more.)

1. A cleaning blade, comprising:

a contact portion which comes into contact with the member to be cleaned,

wherein the contact portion is constituted by a member containing a urethane rubber produced by polymerizing at least a polyol component containing more than 50 mol% and 75 mol% or less of 1, 4-butanediol with respect to the entire polyol component and a polyisocyanate component; and is

In the member constituting the contact portion,

a ratio (M100/Re) of a 100% modulus (M100[ MPa ]) to a coefficient of restitution (Re [% ]) of 0.25 or more, and the coefficient of restitution (Re [% ]) of 25% or more; or

The ratio (EIT/Re) of the indentation elastic modulus (EIT [ MPa ]) to the coefficient of resilience (Re [% ]) is 0.65 or more, and the coefficient of resilience (Re [% ]) is 25% or more.

2. The cleaning blade according to claim 1, wherein the polyol component contains 55 mol% or more and 75 mol% or less of 1, 4-butanediol with respect to the entire polyol component.

3. The cleaning blade according to claim 2, wherein the polyol component contains 55 mol% or more and 60 mol% or less of 1, 4-butanediol with respect to the entire polyol component.

4. The cleaning blade according to claim 1, wherein the urethane rubber has a hard segment and a soft segment, and an average particle diameter of an aggregate of the hard segment is 1 μm or more and 10 μm or less.

5. The cleaning blade according to claim 4, wherein the urethane rubber has a hard segment and a soft segment, and an average particle diameter of an aggregate of the hard segment is 1 μm or more and 5 μm or less.

6. A cleaning device comprising the cleaning blade described in any one of claims 1 to 5.

7. A process cartridge detachable from an image forming apparatus, the process cartridge comprising a cleaning device including the cleaning blade according to any one of claims 1 to 5.

8. An image forming apparatus, comprising:

an image holding member;

a charging device that charges the image holding member;

an electrostatic latent image forming device that forms an electrostatic latent image on the charged surface of the image holding member;

a developing device that develops the electrostatic latent image formed on the surface of the image holding member with a toner to form a toner image;

a transfer device that transfers the toner image formed on the image holding member to a recording medium; and

a cleaning device that cleans the surface of the image holding member by bringing the cleaning blade according to any one of claims 1 to 5 into contact with the surface after the toner image is transferred by the transfer device.

Technical Field

The invention relates to a cleaning blade, a process cartridge, and an image forming apparatus.

Background

Electrophotographic copying machines, printers, facsimile machines, and the like have used a cleaning blade as a cleaning unit that removes residual toner and the like on the surface of an image holding member such as a photoconductor.

For example, japanese laid-open patent application publication No.2014-235423 discloses a cleaning blade comprising a contact portion that is in contact with a member to be cleaned, the contact portion being composed of a member containing a urethane rubber produced by polymerizing at least a polyol component containing 30 mol% or more and 50 mol% or less of 1, 4-butanediol with respect to the entire polyol component. In the member constituting the contact portion, the ratio (M100/Re) of the 100% modulus (M100[ MPa ]) to the coefficient of restitution (Re [% ]) is 0.25 or more, and the coefficient of restitution (Re [% ]) is 25% or more.

Disclosure of Invention

Accordingly, an object of the present invention is to provide a cleaning blade which suppresses local abrasion compared to the following cleaning blades: a cleaning blade comprising a contact portion which is brought into contact with a member to be cleaned, the contact portion being constituted by a member containing a urethane rubber produced by polymerizing at least a polyol component containing 50 mol% or less of 1, 4-butanediol relative to the entire polyol component and a polyisocyanate component, the member having a ratio (M100/Re) of 100% modulus (M100[ MPa ]) to rebound coefficient (Re [% ]) or a ratio (EIT/Re) of indentation elastic modulus (EIT [ MPa ]) to rebound coefficient (Re [% ]) of 0.65 or more and the rebound coefficient (Re [% ]) of 0.25 or more.

According to a first aspect of the present invention, there is provided a cleaning blade comprising a contact portion that comes into contact with a member to be cleaned, the contact portion being composed of a member containing a urethane rubber produced by polymerizing at least a polyol component containing more than 50 mol% and 75 mol% or less of 1, 4-butanediol relative to the entire polyol component, and a polyisocyanate component. In the member constituting the contact portion, a ratio (M100/Re) of a 100% modulus (M100[ MPa ]) to a coefficient of restitution (Re [% ]) is 0.25 or more, and the coefficient of restitution (Re [% ]) is 25% or more, or a ratio (EIT/Re) of an indentation elastic modulus (EIT [ MPa ]) to a coefficient of restitution (Re [% ]) is 0.65 or more, and the coefficient of restitution (Re [% ]) is 25% or more.

According to a second aspect of the present invention, in the cleaning blade of the first aspect of the present invention, the polyol component contains 55 mol% or more and 75 mol% or less of 1, 4-butanediol with respect to the entire polyol component.

According to a third aspect of the present invention, in the cleaning blade of the second aspect of the present invention, the polyol component contains 55 mol% or more and 60 mol% or less of 1, 4-butanediol with respect to the entire polyol component.

According to a fourth aspect of the present invention, in the cleaning blade of the first aspect of the present invention, the urethane rubber has a hard segment and a soft segment, and an average particle diameter of aggregates of the hard segment is 1 μm or more and 10 μm or less.

According to a fifth aspect of the present invention, in the cleaning blade of the fourth aspect of the present invention, the urethane rubber has a hard segment and a soft segment, and an average particle diameter of aggregates of the hard segment is 1 μm or more and 5 μm or less.

According to a sixth aspect of the present invention, a cleaning apparatus includes the cleaning blade of any one of the first to fifth aspects of the present invention.

According to a seventh aspect of the present invention, a process cartridge is detachable from an image forming apparatus, and includes a cleaning device including the cleaning blade of any one of the first to fifth aspects of the present invention.

According to an eighth aspect of the present invention, an image forming apparatus comprises: an image holding member; a charging device that charges the image holding member; an electrostatic latent image forming device that forms an electrostatic latent image on the charged surface of the image holding member; a developing device that develops the electrostatic latent image formed on the surface of the image holding member with a toner to form a toner image; a transfer device that transfers the toner image formed on the image holding member to a recording medium; and a cleaning device that cleans a surface of the image holding member by bringing the cleaning blade of any one of the first to fifth aspects of the present invention into contact with the surface after the toner image is transferred by the transfer device.

According to a first aspect of the present invention, there is provided a cleaning blade that suppresses local abrasion compared to the following cleaning blade: a cleaning blade comprising a contact portion which is brought into contact with a member to be cleaned, the contact portion being constituted by a member containing a urethane rubber produced by polymerizing at least a polyol component containing 50 mol% or less of 1, 4-butanediol relative to the entire polyol component and a polyisocyanate component, the member having a ratio (M100/Re) of 100% modulus (M100[ MPa ]) to rebound coefficient (Re [% ]) of 0.25 or more and a rebound coefficient (Re [% ]) of 0.25 or more, or a ratio (EIT/Re) of indentation elastic modulus (EIT [ MPa ]) to rebound coefficient (Re [% ]) of 0.65 or more and a rebound coefficient (Re [% ]) of 0.25 or more.

According to the second or third aspect of the present invention, there is provided a cleaning blade which suppresses partial wear compared with the case where: the polyol component contains less than 55 mole percent 1, 4-butanediol relative to the entire polyol component.

According to a fourth or fifth aspect of the present invention, there is provided a cleaning blade which suppresses partial wear compared with the case where: the urethane rubber has a hard segment and a soft segment, and the average particle diameter of aggregates of the hard segment is less than 1 μm.

According to a sixth, seventh, or eighth aspect of the present invention, there is provided a cleaning device, a process cartridge, or an image forming apparatus that suppresses a cleaning defect caused by local abrasion in a cleaning blade as compared with a case of having the cleaning blade described below: a cleaning blade comprising a contact portion which is brought into contact with a member to be cleaned, the contact portion being constituted by a member containing a urethane rubber produced by polymerizing at least a polyol component containing 50 mol% or less of 1, 4-butanediol relative to the entire polyol component and a polyisocyanate component, the member having a ratio (M100/Re) of 100% modulus (M100[ MPa ]) to rebound coefficient (Re [% ]) or a ratio (EIT/Re) of indentation elastic modulus (EIT [ MPa ]) to rebound coefficient (Re [% ]) of 0.65 or more and the rebound coefficient (Re [% ]) of 0.25 or more.

Drawings

Exemplary embodiments of the present invention will be described in detail based on the following drawings, in which:

fig. 1 is a schematic view showing an example of a cleaning blade of an exemplary embodiment of the present invention;

fig. 2 is a schematic view showing another example of a cleaning blade of an exemplary embodiment of the present invention;

fig. 3 is a schematic view showing still another example of a cleaning blade of an exemplary embodiment of the present invention;

fig. 4 is a schematic configuration diagram showing an example of an image forming apparatus of an exemplary embodiment of the present invention; and

fig. 5 is a schematic sectional view showing an example of a cleaning apparatus of an exemplary embodiment of the present invention.

Detailed Description

Exemplary embodiments of the present invention are described in detail below.

< cleaning blade >

The cleaning blade of the exemplary embodiment of the present invention includes a contact portion (hereinafter simply referred to as "contact portion") that is in contact with a member to be cleaned, the contact portion being composed of a member containing a urethane rubber that is produced by polymerizing at least a polyol component containing more than 50 mol% and 75 mol% or less of 1, 4-butanediol with respect to the entire polyol component, and a polyisocyanate component.

Further, the member constituting the contact portion satisfies at least one of the following characteristics (1) and (2).

Property (1): the ratio (M100/Re) of the 100% modulus (M100[ MPa ]) to the coefficient of restitution (Re [% ]) is 0.25 or more, and the coefficient of restitution (Re [% ]) is 25% or more.

Property (2): the ratio (EIT/Re) of the indentation elastic modulus (EIT [ MPa ]) to the coefficient of resilience (Re [% ]) is 0.65 or more, and the coefficient of resilience (Re [% ]) is 25% or more.

Therefore, the cleaning blade of the exemplary embodiment of the present invention having the above-described configuration suppresses local abrasion.

A cleaning blade used in an image forming apparatus performs cleaning by sliding on a member to be cleaned (an image holding member or the like), and thus a contact portion with the member to be cleaned is gradually worn away or cut (chipping), causing a cleaning defect.

On the other hand, in view of low cost, it is necessary to use a member containing urethane rubber using 1, 4-butanediol as a member constituting the contact portion of the cleaning blade.

However, parts containing urethane rubber using 1, 4-butanediol tend to have poor resistance to abrasion and cutting. In particular, when a urethane rubber containing 1, 4-butanediol in an amount of 30 mol% or more relative to the entire polyol component is used, the resistance of parts containing the rubber to abrasion and cutting tends to be poor.

In this connection, the cleaning blade described in japanese laid-open patent application publication No.2014-235423 is excellent in both wear resistance and cutting resistance even if the cleaning blade includes a contact portion composed of a member containing urethane rubber using 1, 4-butanediol.

However, the cleaning blade described in japanese pending patent application publication No.2014-235423 may cause local abrasion. The reason for this is presumed to be as follows: the cleaning blade described in japanese laid-open patent application publication No.2014-235423 contains 50 to 70 mol% of a polyol component other than 1, 4-butanediol, and thus the growth of a hard segment composed of 1, 4-butanediol, which is a chain extender of polyurethane, is suppressed. Therefore, the friction coefficient of the surface of the contact portion containing urethane rubber cannot be reduced, and the blade behavior is unstable. Therefore, local wear should occur.

On the other hand, the cleaning blade of the exemplary embodiment uses a urethane rubber obtained by polymerizing at least a polyol component containing more than 50 mol% and 75 mol% or less of 1, 4-butanediol with respect to the entire polyol component and a polyisocyanate component. Therefore, the amount of the polyol component other than 1, 4-butanediol is reduced. Therefore, the growth of the hard segment composed of 1, 4-butanediol should be inhibited. Thus, the surface friction coefficient of the contact portion containing urethane rubber should be reduced to stabilize the blade behavior.

Therefore, the cleaning blade of the exemplary embodiment should suppress local abrasion.

Further, in the cleaning blade of the exemplary embodiment, the member constituting the contact portion satisfies at least one of the above-described characteristics (1) and (2), thereby being excellent in both wear resistance and cutting resistance.

Further, the cleaning blade of the exemplary embodiment suppresses cleaning defects (e.g., image defects such as color streaks, etc.) caused by local abrasion of the cleaning blade.

The M100/Re ratio, EIT/Re ratio and coefficient of restitution of the urethane rubber-containing member are adjusted to the above-mentioned respective ranges by selecting the type and amount of each polymerization component of the urethane rubber and selecting the production conditions.

The configuration of the cleaning blade of the exemplary embodiment of the present invention is described below.

The cleaning blade of the exemplary embodiment of the present invention may include a member (hereinafter referred to as "contact member") containing urethane rubber and satisfying the above-described characteristics, at least in a contact portion with the member to be cleaned. In other words, the cleaning blade may have a double-layer configuration including: a first layer composed of a contact member and contacting with the member to be cleaned, and a second layer provided as a back layer on a back surface of the first layer; alternatively, it may have a configuration including three or more layers. In addition, the cleaning blade may have the following configuration: only the corner portion of the portion in contact with the member to be cleaned is composed of the contact member, and the periphery thereof is composed of another material.

Next, the configuration of the cleaning blade of the exemplary embodiment of the present invention is described in further detail below using the drawings.

Fig. 1 is a schematic view showing a cleaning blade of a first exemplary embodiment in a state of being in contact with a surface of a member to be cleaned (e.g., an image holding member). Fig. 2 is a schematic view showing a cleaning blade of the second exemplary embodiment in a state of being in contact with a surface of a member to be cleaned (e.g., an image holding member). Fig. 3 is a schematic view showing a cleaning blade of a third exemplary embodiment in a state of being in contact with a surface of a member to be cleaned (e.g., an image holding member).

First, each part of the cleaning blade is described with fig. 1. As shown in fig. 1, the cleaning blade has: a contact portion (contact corner portion) 3A that cleans the surface of the image holding member (photosensitive drum) 31 by contacting the driven image holding member 31; a front end face 3B, one side of which is constituted by the contact corner portion 3A and which faces the upstream side in the driving direction (arrow a direction); a ventral surface 3C, one side of which is constituted by the contact corner 3A and which faces the downstream side in the driving direction (the direction of arrow a); and a back surface 3D that shares one side with the front end surface 3B and faces the ventral surface 3C.

The direction parallel to contact corner 3A is referred to as the "depth direction", the direction from contact corner 3A to the side forming distal end surface 3B is referred to as the "thickness direction", and the direction from contact corner 3A to the side forming ventral surface 3C is referred to as the "width direction".

The cleaning blade 342A of the first embodiment shown in fig. 1 is composed of a single material over the entire area including the portion (contact corner) 3A in contact with the photosensitive body drum 31; that is, the structure includes only the contact member.

In addition, as in the second embodiment shown in fig. 2, the cleaning blade of the exemplary embodiment of the present invention may have a double-layer configuration including: a first layer 3421B which includes a portion in contact with the photosensitive body drum 31 (i.e., the contact corner 3A), is formed over the entire region on the ventral surface 3C side, and is composed of a contact member; and a second layer 3422B which is formed as a back layer on the back 3D side of the first layer and is composed of a material different from that of the contact member.

Further, as in the third embodiment shown in fig. 3, the configuration of the cleaning blade of the exemplary embodiment of the present invention may include: a contact member (edge member) 3421C which has a portion (i.e., contact corner 3A) which is in contact with the photosensitive body drum 31, which has a shape in which a quarter-cut cylinder extends in the depth direction, and which is formed of a right-angled portion to form the contact corner 3A, and which is composed of a contact member; and a back member 3422C which is composed of a material different from that of the contact member, and is formed so as to cover the back 3D side in the thickness direction and the side opposite to the front end face 3B in the width direction of the contact member 3421C, that is, to constitute a portion other than the contact member 3421C.

Fig. 3 shows an example in which the contact member is a member having a quarter-cut cylindrical shape, but the contact member is not limited thereto. For example, the contact member may have a shape of a quarter-cut elliptic cylinder, or a shape of a square quadrangular prism or a rectangular prism quadrangular prism, or the like.

In addition, the cleaning blade is generally used by being bonded to a rigid plate-like support material.

Composition of the contact parts

The contact member of the cleaning blade of the exemplary embodiment of the present invention contains urethane rubber. In addition, the contact member satisfies at least one of the above characteristics (1) and (2).

Polyurethane rubber

The urethane rubber is a urethane rubber produced by polymerizing at least a polyol component and a polyisocyanate component. If necessary, the urethane rubber may be a urethane rubber produced by polymerizing a resin other than the polyol component, the resin having a functional group reactive with an isocyanate group of the polyisocyanate.

The urethane rubber preferably has a hard segment and a soft segment. The terms "hard segment" and "soft segment" refer to segments of a urethane rubber material, the material constituting the hard segment being relatively harder than the material constituting the soft segment, and the material constituting the soft segment being relatively softer than the material constituting the hard segment.

Examples of the material constituting the hard segment (hard segment material) include a low molecular weight polyol component in the polyol component, a resin having a functional group reactive with an isocyanate group of a polyisocyanate, and the like. Examples of the material constituting the soft segment (soft segment material) include a high molecular weight polyol component in the polyol component.

The average particle diameter of the aggregate of the hard segment is preferably 1 μm or more and 10 μm or less, and more preferably 1 μm or more and 5 μm or less.

When the average particle diameter of the aggregate of the hard segment is 1 μm or more, the frictional resistance of the surface of the contact member can be easily reduced. Therefore, the blade behavior is stabilized, and partial wear can be easily suppressed.

When the average particle diameter of the aggregate of the hard segment is 10 μm or less, the occurrence of chipping can be easily suppressed.

The average particle size of the aggregate of the hard segment is measured as follows. An image was taken at a magnification of × 20 using a polarization microscope (BX 51-P manufactured by Olympus Corporation), and the image was binarized by image processing. The particle diameters (equivalent circle diameters) of the aggregates were measured at five points (particle diameters of 5 aggregates per point) of each of the 20 cleaning blades, and the average particle diameters of 500 aggregates in total were calculated.

In this case, the image may be binarized using the image processing software OLYMPUS Stream essences (OLYMPUS corporation), and the hue/saturation/lightness threshold may be adjusted so that the crystalline portion and the hard segment aggregate are black, and the amorphous portion (corresponding to the soft segment) is white.

Polyol component

The polyol component contains a high molecular weight polyol and a low molecular weight polyol.

The high molecular weight polyol component is a polyol having a number average molecular weight of 500 or more (preferably 500 or more and 5,000 or less). Examples of the high molecular weight polyol component include known polyols such as polyester polyols made by dehydration condensation of low molecular weight polyols with dibasic acids, polycarbonate polyols made by reaction of low molecular weight polyols with alkyl carbonates, polycaprolactone polyols, polyether polyols, and the like. Examples of commercially available products of high molecular weight polyols are Placcel 205 and Placcel 240 manufactured by Daicel corporation.

The number average molecular weight is a value measured by Gel Permeation Chromatography (GPC). The same applies hereinafter.

These high molecular weight polyols may be used alone or in combination of two or more.

The polymerization ratio of the high molecular weight polyol with respect to the total polymerization components of the urethane rubber is 30 mol% or more and 50 mol% or less, preferably 40 mol% or more and 50 mol% or less.

The low molecular weight polyol component is a polyol having a molecular weight (number average molecular weight) of less than 500. Low molecular weight polyols are materials that function as chain extenders and crosslinkers.

As the low molecular weight polyol, 1, 4-butanediol was used. The proportion of 1, 4-butanediol is more than 50 mol% and 75 mol% or less (preferably 52 mol% or more and 75 mol% or less, more preferably 55 mol% or more and 75 mol% or less, and still more preferably 55 mol% or more and 60 mol% or less) with respect to the entire polyol component (high molecular weight polyol + low molecular weight polyol).

When the proportion of 1, 4-butanediol exceeds 50 mol%, local abrasion is suppressed. On the other hand, when the proportion of 1, 4-butanediol is 75 mol% or less, the occurrence of chipping is suppressed.

The ratio of 1, 4-butanediol to the entire low molecular weight polyol component is 80 mol% or more, preferably 90 mol% or more, and still more preferably 100 mol%. In other words, it is most preferred to use 1, 4-butanediol as the entire low molecular weight polyol component.

Examples of the low molecular weight polyol component other than 1, 4-butanediol include diols (bifunctional), triols (trifunctional), tetraols (tetrafunctional), and the like known as chain extenders and crosslinkers.

These polyhydric alcohols other than 1, 4-butanediol may be used alone or in combination of two or more.

The polymerization ratio of the low-molecular-weight polyol is more than 50 mol% and 75 mol% or less, preferably 52 mol% or more and 75 mol% or less, more preferably 55 mol% or more and 75 mol% or less, and still more preferably 55 mol% or more and 60 mol% or less with respect to the entire polymerization components of the urethane rubber.

Polyisocyanate component

Examples of the polyisocyanate component include diphenylmethane-4, 4' -diisocyanate (MDI), toluene-2, 6-diisocyanate (TDI), hexane-1, 6-diisocyanate (HDI), naphthalene-1, 5-diisocyanate (NDI), 3-dimethylphenyl-4, 4-diisocyanate (TODI), and the like.

More preferably, the polyisocyanate component is diphenylmethane-4, 4' -diisocyanate (MDI), naphthalene-1, 5-diisocyanate (NDI) or Hexamethylene Diisocyanate (HDI).

These polyisocyanate components may be used alone or in combination of two or more.

The polymerization ratio of the polyisocyanate component is 5 mol% or more and 25 mol% or less, preferably 10 mol% or more and 20 mol% or less, with respect to the total polymerization components of the urethane rubber.

Resins having functional groups reactive with isocyanate groups

The resin having a functional group reactive with an isocyanate group (hereinafter referred to as "functional group-containing resin") is preferably a flexible resin, and from the viewpoint of flexibility, it is more preferably an aliphatic resin having a linear structure. Examples of the functional group-containing resin include acrylic resins having two or more hydroxyl groups, polybutadiene resins having two or more hydroxyl groups, epoxy resins having two or more epoxy groups, and the like.

Examples of commercially available products of acrylic resins having two or more hydroxyl groups include Actflow manufactured by Soken chemical engineering Co., Ltd. (grades: UMB-2005B, UMB-2005P, UMB-2005 and UME-2005, etc.).

Examples of commercially available products of polybutadiene resins having two or more hydroxyl groups include Idemitsu Kosan Co., manufactured by Ltd., R-45HT, and the like.

The epoxy resin having two or more epoxy groups preferably has higher flexibility and toughness than the common epoxy resin, but does not have the properties of being hard and brittle as the common epoxy resin. For example, from the viewpoint of molecular structure, the epoxy resin preferably has a structure (flexible backbone) capable of improving the mobility of the main chain in the middle of the main chain structure. Examples of the flexible skeleton include an alkylene skeleton, a cycloalkane skeleton, a polyoxyalkylene skeleton, and the like, and a polyoxyalkylene skeleton is particularly preferred.

In view of physical properties, the above epoxy resin preferably has a low viscosity with respect to molecular weight, as compared with a general epoxy resin. Specifically, the weight average molecular weight is preferably 900. + -.100, and the viscosity at 25 ℃ is preferably 15000. + -.5000 mPas, more preferably 15000. + -.3000 mPas. Examples of commercially available products of epoxy resins having these characteristics include EPLICON EXA-4850-150 manufactured by DIC corporation, and the like.

The polymerization ratio of the functional group-containing resin is within a range that does not impair the effects of the cleaning blade of the exemplary embodiment of the present invention.

Method for producing urethane rubber

The urethane rubber is produced by a general urethane production method such as a prepolymer method or a one-shot method. For the exemplary embodiment of the present invention, the prepolymer method is preferable because a urethane rubber having excellent wear resistance and cut resistance can be obtained, but the production method is not limited.

The cleaning blade is formed by the following method: the cleaning blade-forming composition obtained by the above-described method is molded into a sheet shape by, for example, centrifugal molding, extrusion molding, or the like, and then cut or the like.

In this case, examples of the catalyst for producing the urethane rubber include amine compounds (e.g., tertiary amines, etc.), quaternary ammonium salts, organometallic compounds (e.g., organotin compounds, etc.), and the like.

Examples of tertiary amines include: trialkylamines such as triethylamine and the like; tetraalkyldiamines such as N, N' -tetramethyl-1, 3-butanediamine and the like; aminoalcohols, such as dimethylethanolamine and the like; ester amines such as ethoxylated amines, ethoxylated diamines, and di (diethylethanolamine) adipate, etc.; cyclohexylamine derivatives such as Triethylenediamine (TEDA), N-dimethylcyclohexylamine and the like; morpholine derivatives such as N-methylmorpholine and N- (2-hydroxypropyl) -dimethylmorpholine and the like; piperazine derivatives such as N, N '-diethyl-2-methylpiperazine and N, N' -bis (2-hydroxypropyl) -2-methylpiperazine and the like; and so on.

Examples of the quaternary ammonium salts include 2-hydroxypropyltrimethylammonium octanoate, 1, 5-diazabicyclo [4.3.0] nonene-5 (DBN) octanoate, 1, 8-diazabicyclo [5.4.0] undecene-7 (DBU) -octanoate, DBU-oleate, DBU-p-toluenesulfonate, DBU-formate, 2-hydroxypropyltrimethylammonium formate and the like.

Examples of the organotin compounds include: dialkyltin compounds such as dibutyltin dilaurate and dibutyltin bis (2-ethylhexanoate), and the like; stannous 2-ethylhexanoate and stannous oleate, and the like.

Among these catalysts, triethylene diamine (TEDA) is preferably used as the tertiary amine from the viewpoint of hydrolysis resistance; from the viewpoint of processability, quaternary ammonium salts are preferably used. Among the quaternary ammonium salts, 1, 5-diazabicyclo [4.3.0] nonene-5 (DBN) octanoate, 1, 8-diazabicyclo [5.4.0] undecene-7 (DBU) -octanoate and DBU-formate, which have high reactivity, are preferably used.

The content of the catalyst is preferably 0.0005 mass% or more and 0.03 mass% or less, and particularly preferably 0.001 mass% or more and 0.01 mass% or less, with respect to the entire urethane rubber constituting the contact member.

These may be used alone or in combination of two or more.

Physical properties of the contact parts

The contact member (urethane rubber member) has an M100/Re ratio (the ratio of 100% modulus (M100[ MPa ]) to the coefficient of restitution (Re [% ]) of the contact portion) of 0.25 or more, preferably 0.28 or more, and more preferably 0.3 or more. From the viewpoint of cutting resistance, the upper limit of the M100/Re ratio of the contact member is preferably 1.0 or less, and more preferably 0.9 or less.

The contact member (urethane rubber member) has an EIT/Re ratio (the ratio of indentation elastic modulus (EIT [ MPa ]) to coefficient of restitution (Re [% ])) of 0.65 or more, preferably 0.75 or more, and more preferably 0.85 or more. From the viewpoint of cutting resistance, the upper limit of the EIT/Re ratio of the contact member is preferably 1.1 or less, and more preferably 1.0 or less.

The contact member (urethane rubber member) has a coefficient of restitution (Re [% ]) of 25% or more, preferably 28% or more, and more preferably 30% or more. From the viewpoint of suppressing squealing and wear resistance, the upper limit of the coefficient of restitution (Re [% ]) of the contact portion is preferably 60% or less, and more preferably 40% or less.

From the viewpoint of wear resistance and cut resistance, the 100% modulus (M100[ MPa ]) of the contact member (urethane rubber member) is preferably 4MPa or more and 10MPa or less, and more preferably 5MPa or more and 9MPa or less.

From the viewpoint of wear resistance and cut resistance, the indentation elastic modulus (EIT [ MPa ]) of the contact member (urethane rubber member) is preferably 10MPa or more and 30MPa or less, and more preferably 15MPa or more and 25MPa or less.

The 100% modulus (M100[ MPa ]), the indentation elastic modulus (EIT [ MPa ]), and the coefficient of restitution (Re [% ]) are values measured by the above-described methods in examples described below.

The weight average molecular weight of the contact member (urethane rubber member) is 1000 or more and 4000 or less, preferably 1500 or more and 3500 or less.

Composition of the non-contact parts

Next, as in the second embodiment shown in fig. 2 and the third embodiment shown in fig. 3, the cleaning blade of the exemplary embodiment of the present invention includes a contact member and a region (non-contact member) other than the contact member, which are composed of different materials from each other, and the composition of the non-contact member will be described.

The non-contact member is not particularly limited as long as it has a function of supporting the contact member, and any known material may be used. Examples of the material for the non-contact member include urethane rubber, silicone rubber, fluorine rubber, chloroprene rubber, butadiene rubber, and the like. Among them, urethane rubber is preferable. Examples of the urethane rubber include ester polyurethane and ether polyurethane, with ester polyurethane being preferred.

Production of cleaning blades

In the case where the cleaning blade is constituted only by the contact portion shown in fig. 1, the cleaning blade is manufactured by the above-described method of molding the contact member.

In the case where the cleaning blade has a multi-layer configuration (e.g., a two-layer configuration shown in fig. 2 or the like), the cleaning blade is manufactured by bonding together a first layer as a contact member and a second layer (a plurality of layers in a layer configuration including three or more layers) as a non-contact member. The bonding method preferably uses a double-sided tape or various adhesives. Additionally, the layers may be bonded together by: the materials of the layers are poured into a mold while making a time difference during molding, and the materials are bonded together without providing an adhesive layer.

With the configuration of the contact member (edge member) and the non-contact member (back member) shown in fig. 3, a first mold having a cavity (for pouring the contact member-forming composition into the area) corresponding to a semi-cylindrical shape (formed by overlapping the ventral surfaces 3C of the two contact members 3421C shown in fig. 3) and a second mold having a cavity corresponding to a shape formed by overlapping the ventral surfaces 3 each having two portions of the contact member 3421C and the non-contact member 3422C shown in fig. 3 are prepared. The contact member-forming composition is poured into the cavity of the first mold and cured to form a first molded article having a shape in which two contact members 3421C are spliced to each other. Next, the first mold is removed, and then the second mold is installed so that the first molded article is placed in the cavity of the second mold. Subsequently, the non-contact member forming composition is poured into the cavity of the second mold to cover the first molded article, and then cured to form a second molded article having a shape in which the ventral surfaces 3 of the two contact members 3421C and the two non-contact members 3422C are spliced to each other. Next, the formed second molded article is cut at the center (i.e., at the portion serving as the ventral surface 3C), so that the semi-cylindrical contact part is cut at the center to form a quarter-cut cylindrical shape. The product was further cut into a predetermined size to manufacture a cleaning blade shown in fig. 3.

Application of cleaning blades

When the member to be cleaned is cleaned using the cleaning blade of the exemplary embodiment of the present invention, the member to be cleaned as the cleaning target is not particularly limited as long as the member has a surface that needs to be cleaned in the image forming apparatus. Examples thereof include an intermediate transfer body, a charging roller, a transfer material conveying belt, a paper conveying roller, and a decoloring toner roller that further removes toner from a cleaning brush that removes toner from an image holding member, and the like. In the exemplary embodiment of the present invention, the image holding member is particularly preferable. The cleaning blade of the exemplary embodiment of the present invention can clean a member other than the image forming member (as a member to be cleaned).

(cleaning device, Process Cartridge, and image Forming apparatus)

Next, a cleaning device, a process cartridge, and an image forming apparatus each using the cleaning blade of an exemplary embodiment of the present invention are described.

The cleaning apparatus of the exemplary embodiment of the present invention is not particularly limited as long as the cleaning blade of the exemplary embodiment of the present invention is provided as a cleaning blade that cleans the surface of the member to be cleaned by contacting the surface of the member to be cleaned. For example, the following configuration is an example of the configuration of the cleaning apparatus: the cleaning blade is fixed in a cleaning tank having an opening at one side of the member to be cleaned such that the edge tip is placed at the opening side, and a conveying member is provided to guide foreign matter (e.g., waste toner, etc.) recovered from the surface of the member to be cleaned by the cleaning blade into a foreign matter recovery container. In addition, the cleaning apparatus of the exemplary embodiment of the present invention may use two or more cleaning blades of the exemplary embodiment of the present invention.

When the cleaning blade of the exemplary embodiment of the present invention is used to clean the image holding member, in order to suppress image flow during image formation, a force NF (normal force) with which the cleaning blade is pushed toward the image holding member is preferably 1.3gf/mm or more and 2.3gf/mm or less, and more preferably 1.6gf/mm or more and 2.0gf/mm or less.

The length of penetration of the tip portion of the cleaning blade into the image holding member is preferably 0.8mm or more and 1.2mm or less, and more preferably 0.9mm or more and 1.1mm or less.

The angle W/a (working angle) of the contact portion between the cleaning blade and the image holding member is preferably 8 ° or more and 14 ° or less, and more preferably 10 ° or more and 12 ° or less.

The process cartridge of the exemplary embodiment of the present invention is not particularly limited as long as the cleaning apparatus of the exemplary embodiment of the present invention is provided as a cleaning apparatus that cleans the surface of one or more members to be cleaned (e.g., an image holding member and an intermediate transfer body, etc.) by contacting the surface. For example, a process cartridge, which is detachable from an image forming apparatus, is in the form of including an image holding member and a cleaning device (which cleans the surface of the image holding member) according to an exemplary embodiment of the present invention. For example, in a so-called tandem type machine having image holding members corresponding to respective colors of toners, the cleaning device of the exemplary embodiment may be provided on each image holding member. In addition, the cleaning apparatus of the exemplary embodiment may be used in combination with a cleaning brush or the like.

Examples of cleaning blade, image forming apparatus, and cleaning device

Next, examples of a cleaning blade of an exemplary embodiment of the present invention, and an image forming apparatus and a cleaning device each using the cleaning blade will be described in further detail with reference to the drawings.

Fig. 4 is a schematic diagram showing an example of an image forming apparatus of an exemplary embodiment of the present invention and showing a so-called tandem type image forming apparatus.

In fig. 4, reference numeral 21 denotes a housing, reference numerals 22, 22a to 22d each denote an image forming unit, reference numeral 23 denotes a belt module, reference numeral 24 denotes a recording medium supply cassette, reference numeral 25 denotes a recording medium conveying path, reference numeral 30 denotes a photosensitive body unit, reference numeral 31 denotes a photosensitive body drum, reference numeral 33 denotes a developing unit, reference numeral 34 denotes a cleaning device, reference numerals 35, 35a to 35d each denote a toner cartridge, reference numeral 40 denotes an exposure unit, reference numeral 41 denotes a unit case, reference numeral 42 denotes a polygon mirror, reference numeral 51 denotes a first transfer device, reference numeral 52 denotes a second transfer device, reference numeral 53 denotes a belt cleaning device, reference numeral 61 denotes a feed roller, reference numeral 62 denotes a conveying roller, reference numeral 63 denotes a registration roller, reference numeral 66 denotes a fixing device, reference numeral 67 denotes an output roller, reference numeral 68 denotes a conveying portion, reference numeral 71 denotes a manual feeding device, reference numeral 72 denotes a feeding roller, reference numeral 73 denotes a duplex recording unit, reference numeral 74 denotes a guide roller, reference numeral 76 denotes a conveying path, reference numeral 77 denotes a conveying roller, reference numeral 230 denotes an intermediate transfer belt, reference numerals 231 and 232 each denote a backup roller, reference numeral 521 denotes a second transfer roller, and reference numeral 531 denotes a cleaning blade.

The tandem type image forming apparatus shown in fig. 4 includes: image forming units 22 (specifically, 22a to 22d) of four colors (yellow, magenta, cyan, and black in the exemplary embodiment) provided in the casing 21, and a belt module 23 provided above the image forming units 22 and containing an intermediate transfer belt 230 that circulates in the arrangement direction of the image forming units 22. On the other hand, a recording medium supply cassette 24 accommodating a recording medium (not shown), such as paper or the like, is provided in a lower portion of the housing 21, and a conveying path 25 serving as a conveying path of the recording medium from the recording medium supply cassette 24 is provided in the vertical direction.

In the exemplary embodiment of the present invention, the image forming units 22(22a to 22d) form toner images of, for example, yellow, magenta, cyan, and black, respectively, in order from the upstream side in the circulating direction of the intermediate transfer belt 230 (the arrangement is not necessarily in this order), and the photoconductor unit 30, the developing unit 33, and the common exposure unit 40 are provided.

The photoconductor units 30 each include a sub-cartridge integrally accommodating, for example, a photoconductor drum 31, a charging device (charging roller) 32 that precharges the photoconductor drum 31, and a cleaning device 34 that removes residual toner on the photoconductor drum 31.

The developing unit 33 develops the electrostatic latent image (negative polarity, for example, in the exemplary embodiment) formed on the charged photoconductor drum 31 with the toner of the corresponding color by exposure by the exposure unit 40, and forms a process cartridge (so-called consumer replaceable unit) integrated with, for example, a sub-cartridge containing the photoconductor unit 30.

Obviously, the photosensitive body unit 30 may also be provided as a single process cartridge separate from the developing unit 33. In addition, in fig. 4, reference numerals 35(35a to 35d) each denote a toner cartridge for supplying toner of each color component (supplied through a toner supply path, not shown) to each developing unit 33.

On the other hand, the exposure unit 40 includes a unit case 41 that houses, for example, four semiconductor lasers (not shown), a polygon mirror 42, an imaging lens (not shown), and mirrors (not shown) corresponding to the respective photoconductor units 30. Therefore, the light from the semiconductor laser of each color component is deflectively scanned by the polygon mirror 42, and a light image is guided to the corresponding exposure point on the photosensitive drum 31 through the imaging lens and the mirror.

In the exemplary embodiment of the present invention, the belt module 23 includes, for example, an intermediate transfer belt 230 stretched between a pair of backup rollers (one of which is a drive roller) 231 and 232, and a first transfer device (a first transfer roller in this example) 51 is provided on the back surface of the intermediate transfer belt 230 so as to correspond to the photosensitive body drum 31 of each photosensitive body unit 30. Therefore, when a voltage of a polarity opposite to the charge polarity of the toner is applied to the first transfer device 51, the toner image on the photoconductor drum 31 is electrostatically transferred to the intermediate transfer belt 230 side. Further, the secondary transfer device 52 is disposed at a position corresponding to the backup roller 232, and is located downstream of the most downstream side image forming unit 22d of the intermediate transfer belt 230; and the image primarily transferred on the intermediate transfer belt 230 is secondarily transferred to a recording medium (co-transfer).

In an exemplary embodiment of the present invention, the second transfer apparatus 52 includes: a second transfer roller 521 disposed in pressing contact with the toner image holding side of the intermediate transfer belt 230, and a back roller (which also serves as a backup roller 232 in this example) disposed on the back side of the intermediate transfer belt 230 and serving as a counter electrode of the second transfer roller 521. In addition, for example, the second transfer roller 521 is grounded, and a bias of the same polarity as the charge polarity of the toner is applied to the back roller (the backup roller 232).

Further, the belt cleaning device 53 is disposed upstream of the most upstream side image forming unit 22a of the intermediate transfer belt 230, and therefore, it removes residual toner on the intermediate transfer belt 230.

In addition, a feed roller 61 that feeds the recording medium is provided on the recording medium supply cassette 24, and a transport roller 62 that feeds the recording medium is provided immediately after the feed roller 61. In addition, a registration roller 63 is provided in the recording medium conveyance path 25 at a position before and immediately adjacent to the second transfer position so that the recording medium is supplied to the second transfer position at a predetermined timing. On the other hand, a fixing device 66 is provided in the recording medium conveyance path 25 downstream of the second transfer position, and an output roller 67 for outputting the recording medium is provided downstream of the fixing device 66, and the output recording medium is accommodated in a conveyance section 68 formed in an upper portion of the casing 21.

Further, a manual feeding device (MSI)71 is provided at one side of the housing 21, and the recording medium on the manual feeding device 71 is conveyed to the recording medium conveying path 25 by a conveying roller 72 and a conveying roller 62.

Further, a double-sided recording unit 73 is attached to the housing 21. When the duplex mode is selected to record images on both sides of the recording medium, the duplex recording unit 73 receives the recording medium after one-side recording by reversing the conveying roller 67 and using the guide roller 74 in front of the injection port, and the recording medium is conveyed by the conveying roller 77 along the internal recording medium return conveying path 76 and is supplied to the registration roller 63 side again.

The cleaning device 34 provided in the tandem type image forming apparatus shown in fig. 4 is described next in detail.

Fig. 5 is a schematic sectional view showing an example of the cleaning apparatus of the exemplary embodiment of the invention, and also shows the photosensitive body drum 31 and the charging roller 32, and the developing unit 33 accommodated in the sub-cartridge together with the cleaning apparatus 34 shown in fig. 4.

In fig. 5, reference numeral 32 denotes a charging roller (charging device), reference numeral 331 denotes a unit case, reference numeral 332 denotes a developing roller, reference numeral 333 denotes a toner conveying member, reference numeral 334 denotes a conveying blade, reference numeral 335 denotes a finishing member, reference numeral 341 denotes a cleaning case, reference numeral 342 denotes a cleaning blade, reference numeral 344 denotes a film seal, and reference numeral 345 denotes a conveying member.

The cleaning device 34 includes a cleaning case 341 which contains residual toner and has an opening opposed to the photoconductor drum 31; further, a cleaning blade 342 provided in contact with the photosensitive body drum 31 is attached at the lower edge of the opening of the cleaning case 341 by a bracket (not shown). On the other hand, a film seal 344 is attached at the upper edge of the opening of the cleaning tank 341 to maintain airtightness between the cleaning device and the photosensitive body drum 31. Further, reference numeral 345 denotes a conveying member that guides the waste toner contained in cleaning case 341 into the wing waste toner container.

The cleaning blade provided on the cleaning device 34 is described in detail below using the drawings.

Fig. 1 is a schematic sectional view showing an example of a cleaning blade of an exemplary embodiment of the present invention, and shows the cleaning blade 342 shown in fig. 5 and the photosensitive body drum 31 in contact with the cleaning blade 342.

In the exemplary embodiment of the present invention, the cleaning blade of the exemplary embodiment of the present invention is used as the cleaning blade 342 in the cleaning apparatus 34 of each of the image forming units 22(22a to 22d), and the cleaning blade of the exemplary embodiment of the present invention may be used as the cleaning blade 531 used in the belt type cleaning apparatus 53.

In addition, for example, as shown in fig. 5, the developing unit (developing device) 33 used in the exemplary embodiment of the present invention includes a unit case 331 that contains developer and has an opening opposed to the photosensitive body drum 31. The developing roller 332 is disposed at a position facing the opening of the unit casing 331, and a toner conveying member 333 for agitating and conveying the developer is disposed in the unit casing 331. Further, a conveyance paddle 334 is provided between the developing roller 332 and the toner conveyance member 333.

During development, the developer is supplied to the developing roller 332, and then conveyed to a developing region facing the photosensitive body drum 31 in a state where the thickness of the developer layer is adjusted by, for example, the trimming member 335.

In the exemplary embodiment of the present invention, the developing unit 33 uses, for example, a two-component toner containing a toner and a carrier, but a single-component toner containing only a toner may also be used.

The operation of the image forming apparatus of the exemplary embodiment is described next. First, when the image forming units 22(22a to 22d) each form a single-color toner image corresponding to each color, the single-color toner images of the respective colors are successively superimposed in correspondence with original information and then primarily transferred to the surface of the intermediate transfer belt 230. Then, the second transfer device 52 transfers the color toner image transferred to the surface of the intermediate transfer belt 230 to the surface of the recording medium, and the fixing device 66 fixes the recording medium to which the color toner image has been transferred, and then outputs to the conveying portion 68.

On the other hand, in each of the image forming units 22(22a to 22d), the cleaning device 34 cleans the residual toner on the photoconductor drum 31, and the belt cleaning device 53 cleans the residual toner on the intermediate transfer belt 230.

In the above-described image forming process, the cleaning device 34 (or the belt cleaning device 53) cleans the remaining toner.

The cleaning blade 342 may be fixed by a spring material, instead of being directly fixed to a frame member in the cleaning device 34 as shown in fig. 5.