JP6544156B2 - Cleaning blade, cleaning device, process cartridge and image forming apparatus - Google Patents

Description

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

  2. Description of the Related Art A cleaning blade is conventionally used as a cleaning unit for cleaning the surface of a member to be cleaned such as an image carrier to remove residual toner and the like in electrophotographic copying machines, printers, facsimiles and the like.

  For example, Patent Document 1 discloses a cleaning blade for an electrophotographic apparatus comprising a blade member made of a polyurethane elastomer, a support member, and an adhesive layer, wherein the polyurethane elastomer comprises a high molecular weight polyol, an isocyanate compound and a chain extension / crosslinking agent. Said high molecular weight polyol comprises polyethylene adipate, said chain extender / crosslinker comprises 1,4-butanediol, 1,6-hexanediol and trimethylolpropane, and 1 in said chain extender / crosslinker The ratio of the total number of hydroxyl groups of 1, 4-butanediol and the total number of hydroxyl groups of 1,6-hexanediol to the number of hydroxyl groups of trimethylolpropane is 85: 15 to 60: 40, and 1,6-hexanediol The ratio of the number of hydroxyl groups to the number of hydroxyl groups of 1,4-butanediol is 7: a cleaning blade for an electrophotographic apparatus is disclosed which is 3 to 50:50.

  In addition, Patent Document 2 shows an electrophotographic apparatus blade including an edge portion and a base portion different in material, wherein at least the edge portion is made of ester-based polyurethane, and the base portion other than the edge portion is made of ether-based polyurethane. A blade for a photographic device is disclosed.

JP-A-8-179669 JP 2008-185716 A

Since the cleaning blade is used in contact with and repeated contact with the member to be cleaned, permanent deformation may occur at the contact portion with the member to be cleaned.
An object of the present invention is to provide a cleaning blade in which permanent deformation at a contact portion with a member to be cleaned is suppressed as compared with the case where ΔSP value (H−S) is less than 4.0.

In order to achieve the above object, the following invention is provided.
The invention according to claim 1 is
The absolute value (ΔSP value (H) of the difference between the solubility parameter (SP value (H)) of the hard segment component and the solubility parameter (SP value (S)) of the soft segment component including a hard segment component and a soft segment component A cleaning blade in which at least a contact portion in contact with the member to be cleaned is formed of a polyurethane member containing polyurethane having a S of 4.0 or more and 5.5 or less.

The invention according to claim 2 is
The cleaning according to claim 1, wherein the solubility parameter (SP value (S)) of the soft segment component is 10.5 or less, and the solubility parameter (SP value (H)) of the hard segment component is 12.0 or more. blade.

The invention according to claim 3 is
The cleaning blade according to claim 1 or 2, wherein the polyurethane is a resin in which diphenylmethane diisocyanate (MDI) and a linear diol having 3 or more carbon atoms are at least polymerized as the hard segment component.

The invention according to claim 4 is
The polyurethane is a resin obtained by polymerizing at least one polyol selected from the group consisting of a polyether polyol and a polyester polyol obtained by polymerizing at least a linear diol having 9 or more carbon atoms as the soft segment component. The cleaning blade according to any one of claims 1 to 3.

The invention according to claim 5 is
A cleaning device comprising the cleaning blade according to any one of claims 1 to 4.

The invention according to claim 6 is
A process cartridge comprising the cleaning device according to claim 5 and removable with respect to an image forming apparatus.

The invention according to claim 7 is
An image carrier,
Charging means for charging the surface of the image carrier;
Electrostatic latent image forming means for forming an electrostatic latent image on the surface of the charged image carrier;
Developing means for developing the electrostatic latent image formed on the surface of the image carrier with a developer containing toner to form a toner image;
A transfer unit that transfers the toner image to the surface of a recording medium;
A cleaning device comprising the cleaning device according to claim 5, wherein the cleaning blade is brought into contact with the image carrier to clean the surface of the image carrier.
An image forming apparatus comprising:

  According to the invention as set forth in claims 1, 2, 3 and 4, the permanent deformation at the contact portion with the member to be cleaned is suppressed as compared with the case where the ΔSP value (H−S) is less than 4.0. A cleaning blade is provided.

  According to the invention of claim 5, the permanent deformation at the contact portion of the cleaning blade with the member to be cleaned is suppressed as compared to the case where the cleaning blade having the ΔSP value (H-S) of less than 4.0 is provided. Cleaning device is provided

  According to the invention as set forth in claims 7 and 8, compared to the case where the cleaning blade having the ΔSP value (H-S) of less than 4.0 is provided, the process in which the generation of the streaky image defect in the image is suppressed. A cartridge and an image forming apparatus are provided.

It is the schematic which shows an example of the cleaning blade in this embodiment. FIG. 7 is a schematic view showing a state in which the cleaning blade in the present embodiment is in contact with the image carrier being driven. FIG. 1 is a schematic view showing an example of an image forming apparatus according to the present embodiment. It is a schematic cross section which shows an example of the cleaning apparatus in this embodiment. It is the schematic which shows another example of the cleaning blade in this embodiment. It is the schematic which shows another example of the cleaning blade in this embodiment.

  Hereinafter, embodiments of the cleaning blade, the cleaning device, the process cartridge, and the image forming apparatus of the present invention will be described in detail.

<Cleaning blade>
In the cleaning blade according to the present embodiment, at least the contact portion in contact with the member to be cleaned is formed of a polyurethane member containing a polyurethane including a hard segment component (H phase) and a soft segment component (S phase).
The absolute value (ΔSP value (H-S)) of the difference between the solubility parameter (SP value (H)) of the hard segment component and the solubility parameter (SP value (S)) of the soft segment component is 4.0. The above is 5.5 or less.

2. Description of the Related Art Conventionally, in an electrophotographic image forming apparatus such as a copying machine, a printer, and a facsimile, a cleaning blade is used as a cleaning unit for removing foreign substances such as residual toner on the surface of an image carrier. Since the cleaning blade is generally in contact with a member to be cleaned such as an image carrier for a long period of time, permanent deformation, which is also called as "settle", may occur at the contact portion with the member to be cleaned. The permanent deformation is more likely to occur as the temperature is higher. When permanent deformation occurs in the cleaning blade, the pressure applied to the member to be cleaned changes and falls out of the required range, and foreign matters such as residual toner and external additives are easily slipped between the member to be cleaned and the cleaning blade.
In particular, in an electrophotographic image forming apparatus using toner, in recent years, toner diameter reduction and spheroidization are required, and therefore, it is more likely that the residual toner is likely to slip through at the contact portion between the member to be cleaned and the cleaning blade. ing. In this way, when the foreign toner such as the residual toner or the external additive passes through, it causes a streak-like image defect in the image forming apparatus.

  On the other hand, in the cleaning blade according to the present embodiment, the absolute value (ΔSP value) of the difference between the solubility parameter (SP value (H)) of the hard segment component and the solubility parameter (SP value (S)) of the soft segment component in polyurethane. When (HS) is in the above range, the occurrence of permanent deformation is suppressed as compared to the case where the ΔSP value (HS) is less than 4.0.

The reason why this effect is exerted is guessed as follows, though it is not clear.
The absolute value (ΔSP value (H-S)) of the difference between the SP value (H) of the hard segment component (H phase) of the polyurethane and the SP value (S) of the soft segment component (S phase) By increasing the size, permanent deformation at the contact portion of the cleaning blade is suppressed. This is because the larger the ΔSP value (H-S), the easier the phase separation between the hard segment component (H phase) and the soft segment component (S phase) occurs, and the respective characteristics of the H phase and the S phase become easier to be obtained . As a result, the mechanical strength characteristics by the H phase and the softness characteristics by the S phase are further improved, and the plastic deformation is suppressed.

· ΔSP value (H-S)
The ΔSP (HS) is 4.0 or more and 5.5 or less, preferably 4.0 or more and 5.0 or less, and more preferably 4.0 or more and 4.5 or less.
When the ΔSP value (H−S) is smaller than 4.0, permanent deformation occurs at the contact portion with the member to be cleaned, and the cleaning performance is lowered. It is thought that this is because the S phase enters into the H phase and the performance of permanent deformation resistance is not exhibited well because the phase separation between the hard segment component (H phase) and the soft segment component (S phase) hardly occurs. Be
On the other hand, when the ΔSP value (H−S) exceeds 5.5, the abrasion resistance is poor. It is considered that this is because the reactivity is lowered to make it difficult to form the H phase, and as a result, the strength is inferior.

-Calculation of solubility parameter (SP value) In the present specification, solubility parameters (SP value (H) and SP value (S)) of hard segment component (H phase) and soft segment component (S phase) of polyurethane (unit: (Cal / cm ³ ) ^1/2 ] is a value obtained by the Fedors method. Specifically, the SP value [δ] is calculated by the following equation (1).
In following formula (1), (triangle | delta) Evap shows molar heat of vaporization (cal / mol), V shows the molar volume (cm < ³ > / mol) in 25 degreeC. The molar heat of vaporization (.DELTA.Evap) and the molar volume (V) at 25.degree. C. can both be determined by adding together certain values belonging to atoms and groups in the molecule.
SP value [δ] = √ΔEvap / V (1)

In addition, although it is common to use cal as the unit of SP value, when converted to SI unit system, (cal / cm ³ ) ^1/2 = 2.046 × 10 ³ (J / m ³⁾ ) You may use ^1/2 relationship. In the description of the present specification, the unit of the SP value may be omitted, but the SP value is a value represented by the unit of (cal / cm ³ ) ^1/2 .
The difference between the SP value (H) of the H phase and the SP value (S) of the S phase (ΔSP value (H-S), (absolute value)) tends to increase the affinity of both phases as the value decreases.
The adjustment of the ΔSP value (H-S) of the polyurethane in the present embodiment is made by the solubility parameter (SP value (H)) of the hard segment component (H phase) and the solubility parameter (SP value (S value) of the soft segment component (S phase) It is done by adjusting each). The preparation method of the solubility parameter of each of H phase and S phase is explained in full detail later.

Hard Segment Component and Soft Segment Component in Polyurethane The polyurethane in the cleaning blade according to the present embodiment includes a hard segment component (H phase) and a soft segment component (S phase). Here, the polyurethane is a polymer obtained by polymerizing at least a polyol and a polyisocyanate, the polyol corresponds to a soft segment component (S phase), and the polyisocyanate corresponds to a hard segment component (H phase).
Further, the polyurethane in the present embodiment may be a polymer obtained by further polymerizing a chain extender, a crosslinking agent and the like in addition to the polyol and the polyisocyanate. When at least one of a chain extender and a crosslinking agent is contained as a polymerization component, the chain extender and the crosslinking agent also correspond to the hard segment component (H phase).

  Next, the configuration of the cleaning blade according to the present embodiment will be described in detail.

  The cleaning blade according to this embodiment is disposed in contact with the surface of the member 31 to be cleaned, as shown in FIG. When the member to be cleaned 31 is driven, as shown in FIG. 2, sliding occurs at the contact portion between the cleaning blade 342 and the member to be cleaned 31 to form the nip portion T, and the surface of the member to be cleaned 31 is cleaned.

First, each part of the cleaning blade will be described with reference to the drawings. In the following, as shown in FIG. 1, the cleaning blade is in contact with the driven member (image carrier / photosensitive drum) 31 to be driven and the contact angle portion for cleaning the surface of the member (image carrier) 31 to be cleaned 3A, a tip surface 3B where the contact angle portion 3A constitutes one side and faces the upstream side in the driving direction (arrow A direction), and the contact angle portion 3A constitutes one side and the driving direction It has a belly 3C facing the downstream side (the direction of arrow A), and a back 3D that shares one side with the tip 3B and faces the belly 3C.
In addition, the direction along the direction in which the contact angle portion 3A contacts the member to be cleaned 31 (the depth direction in FIG. 1) is the depth direction, and the direction from the contact angle portion 3A to the end surface 3B is the thickness direction The direction from the contact angle portion 3A to the side on which the abdominal surface 3C is formed is referred to as the width direction.
In FIG. 1, the direction in which the image carrier (photosensitive drum) 31 is driven is drawn as arrow A for convenience, but FIG. 1 shows a state in which the image carrier 31 is stopped.

  FIG. 1 is a schematic view showing a cleaning blade according to the first embodiment, and is a view showing a state in contact with the surface of a photosensitive drum as an example of a member to be cleaned. FIG. 5 is a view showing the cleaning blade according to the second embodiment, and FIG. 6 is a view showing the cleaning blade according to the third embodiment in contact with the surface of the photosensitive drum.

  The cleaning blade 342A according to the first embodiment shown in FIG. 1 is composed entirely of a single material including the portion (contact angle portion 3A) in contact with the photosensitive drum 31, that is, only the polyurethane member It is an aspect which consists of.

  As in the second embodiment shown in FIG. 5, the cleaning blade according to this embodiment includes a portion (contact angle portion 3A) in contact with the photosensitive drum 31, and is formed over the entire abdominal surface 3C side and It is a two-layer configuration provided with a first layer 3421B made of a polyurethane member and a second layer 3422B formed on the back surface 3D side of the first layer and made of a material different from the polyurethane member. May be

Furthermore, as in the third embodiment shown in FIG. 6, the cleaning blade according to the present embodiment includes a portion in contact with the photosensitive drum 31, that is, the contact angle portion 3A, and the cylinder cut into 1/4 has a depth direction A contact member (edge member) 3421C made of a polyurethane member, the right-angled portion of the shape having the extended shape forming the contact angle portion 3A, the back surface 3D side in the thickness direction of the contact member 3421C and the tip surface in the width direction A back member 3422C made of a material different from the polyurethane member may be provided to cover the side opposite to 3B, that is, to constitute the portion other than the contact member 3421C.
In addition, although the example of the member which has a cylindrical shape cut | disconnected into 1/4 as a contact member was shown in FIG. 6, it is not limited to this. The contact member may be, for example, a shape in which an elliptical cylinder is cut into 1/4, a square prism, a rectangular prism, or the like.

(Polyurethane member)
The polyurethane member in the cleaning blade according to the present embodiment contains polyurethane (polyurethane rubber). The polyurethane is synthesized by polymerizing at least a polyisocyanate and a polyol. In addition to the polyol, a resin having a functional group capable of reacting with an isocyanate group may be used. The polyurethane has a hard segment component (H phase) and a soft segment component (S phase).
Here, in the resin, the hard segment component (H phase) and the soft segment component (S phase) are made of a material which is relatively harder in the material constituting the former than in the material constituting the latter in the resin, the latter The material which comprises the above means the segment which consists of a material relatively softer than the material which constitutes the former. In the present embodiment, the polyol corresponds to the soft segment component (S phase), and the polyisocyanate corresponds to the hard segment component (H phase). The polymer may also be a polymer obtained by further polymerizing a chain extender, a crosslinking agent, etc. in addition to the above-mentioned polyol and polyisocyanate, in which case the chain extender and the crosslinking agent also correspond to the hard segment component (H phase). .

-Soft segment component-
-Polyol As a material which comprises a soft segment component (S phase), a polyol is mentioned, The polyester polyol obtained by dehydration condensation with diol and a dibasic acid, polyether polyol, polycarbonate obtained by the reaction of diol and alkyl carbonate Polyol, polycaprolactone polyol, etc. are mentioned.

Examples of the diol used for the polymerization of the polyester polyol include ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol and 1,7-heptanediol. 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,11-undecanediol, 1,12-dodecanediol, 1,13-tridecanediol, 1,14-tetradecanediol And 1,18-octadecanediol and 1,20-eicosandiol.
Among these, polyester polyols in which a linear diol having 9 or more carbon atoms (a diol in which two hydroxyl groups are substituted at both ends of a carbon chain and a carbon chain between the two hydroxyl groups is linear) are more preferable. The carbon number is more preferably 9 or more and 12 or less, and still more preferably 9 or more and 11 or less.
Moreover, as a dibasic acid used for polymerization of polyester polyol, for example, oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelinic acid, sebacic acid, 1,9-nonanedicarboxylic acid, 1,10-decanedicarboxylic acid, 1,11-undecanedicarboxylic acid, 1,12-dodecanedicarboxylic acid, 1,13-tridecanedicarboxylic acid, 1,14-tetradecanedicarboxylic acid, 1,16-hexadecanedicarboxylic acid, 1,18-octadecanedicarboxylic acid, or its lower alkyl ester or acid anhydride. Among these, succinic acid, adipic acid and sebacic acid are preferable.

  The polyester polyol is preferably a polyester polyol obtained by dehydration condensation of 1,9-nonanediol and adipic acid, or a polyester polyol obtained by dehydration condensation of 1,9-nonanediol and sebacic acid. In particular, polyester polyols in which a linear diol having 9 or more carbon atoms is polymerized are preferable, that is, polyester polyols obtained by dehydration condensation of a linear diol having 9 or more carbon atoms and a dibasic acid are preferable.

  Examples of polyether polyols include polyalkylene glycols such as polyethylene glycol, polypropylene glycol, and polytetramethylene glycol, or copolymers thereof, and the like. Among them, polytetramethylene ether glycol (PTMG) is preferable.

  As the soft segment component, it is preferable to use at least one polyol selected from the group consisting of a polyether polyol and a polyester polyol obtained by polymerizing a linear diol having at least 9 carbon atoms or more. These may be used alone or in combination of two or more.

The solubility parameter (SP value (S)) of the soft segment component is preferably in the range of 10.5 or less, more preferably in the range of 10.0 or less, and still more preferably in the range of 9.5 or less. By setting the above range, it becomes easy to control the value of ΔSP value (H−S) to the above range.
Further, the lower limit value is not particularly limited, but a range of 7.5 or more is preferable, a range of 8.0 or more is more preferable, and a range of 8.5 or more is more preferable. By setting the lower limit value to the range, the molecular mobility of the soft segment is improved, and thus the chipping resistance of the cleaning blade is improved.

  As a method of adjusting the SP value of the soft segment component (S phase), there is a method of selecting the material of the polyol to be used. In addition, it is also useful to use diols having different carbon numbers, and the use of short-chain diols increases the polarity and the SP value, while the use of long-chain diols decreases the polarity and the SP value decreases.

-Hard segment component-
Polyisocyanate Polyisocyanate is used as a hard segment component in the synthesis of polyurethane. As the polyisocyanate, for example, 4,4'-diphenylmethane diisocyanate (MDI), 2,6-toluene diisocyanate (TDI), 1,6-hexane diisocyanate (HDI), 1,5-naphthalene diisocyanate (NDI), 3,3 -Dimethylphenyl-4,4-diisocyanate (TODI) etc. are mentioned.
The polyisocyanate is preferably 4,4'-diphenylmethane diisocyanate (MDI), 1,5-naphthalene diisocyanate (NDI), hexamethylene diisocyanate (HDI), more preferably 4,4'-diphenylmethane diisocyanate (MDI) .

  The blending amount of polyisocyanate is preferably 20 parts by mass or more and 40 parts by mass or less, and more preferably 20 parts by mass or more and 35 parts by mass or less based on 100 parts by mass of the resin having a functional group capable of reacting with the isocyanate group possessed by the polyisocyanate. Is more preferable, and 20 parts by mass or more and 30 parts by mass or less is more preferable. When the content is 20 parts by mass or more, a large amount of urethane bond is secured to grow hard segments, and the required hardness can be obtained. On the other hand, when the amount is 40 parts by mass or less, the hard segment does not become too large, stretchability is obtained, and the occurrence of chipping of the cleaning blade is suppressed.

-Chain extender The polyurethane in the present embodiment may be a polymer in which a chain extender is polymerized as a hard segment component.
The chain extender is not particularly limited as long as it is conventionally known, and, for example, ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6 -Trivalent or higher polyvalent compounds such as glycols such as hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, diethylene glycol, neopentyl glycol etc., diglycerin, pentaerythritol etc. Alcohol, diisopropanolamine, aminoisopropanol such as triisopropanolamine, triethanolamine, etc. are used. Among these, glycols and trihydric alcohols are preferable, and glycols are more preferable.
In addition, as the glycols, in particular, a linear diol having 3 or more carbon atoms (a diol in which two hydroxyl groups are substituted at both ends of the carbon chain and the carbon chain between the two hydroxyl groups is linear) is preferable. The carbon number is more preferably 3 or more and 5 or less, and still more preferably 3 or more and 4 or less. 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, and 1,6-hexanediol are more preferable.

It is also desirable to use a resin having a functional group capable of reacting with an isocyanate group as a chain extender. The resin is preferably a flexible resin, and more preferably an aliphatic resin having a linear structure from the viewpoint of flexibility. As a specific example, it is desirable to use an acrylic resin containing two or more hydroxyl groups, a polybutadiene resin containing two or more hydroxyl groups, an epoxy resin having two or more epoxy groups, and the like.
As a commercial item of an acrylic resin containing two or more hydroxyl groups, for example, ActFlow (grade: UMB-2005B, UMB-2005P, UMB-2005, UME-2005, etc.) manufactured by Soken Chemical Co., Ltd. can be mentioned.
As a commercial item of polybutadiene resin containing 2 or more hydroxyl groups, Idemitsu Kosan Co., Ltd. product, R-45 HT etc. are mentioned, for example.
The epoxy resin having two or more epoxy groups is not a hard and brittle one like the conventional general epoxy resin, and is preferably one having a softer toughness than the conventional epoxy resin. As the above-mentioned epoxy resin, for example, in terms of molecular structure, one having a structure (flexible skeleton) capable of increasing the flexibility of the main chain in its main chain structure is preferable, and as the flexible skeleton, Examples thereof include an alkylene skeleton, a cycloalkane skeleton, a polyoxyalkylene skeleton and the like, and a polyoxyalkylene skeleton is particularly preferable. Further, in terms of physical properties, an epoxy resin having a viscosity lower than that of a conventional epoxy resin is preferable. Specifically, the weight average molecular weight is preferably in the range of 900 ± 100, and the viscosity at 25 ° C. is preferably in the range of 15000 ± 5000 mPa · s, and more preferably in the range of 15000 ± 3000 mPa · s. desirable. As a commercial item of the epoxy resin which has this characteristic, the product made from DIC and EPLICON EXA-4850-150 etc. are mentioned, for example.

  The chain extender is more preferably a linear diol having 3 or more carbon atoms. The chain extenders may be used alone or in combination of two or more.

  The blending amount of the chain extender with respect to 100 parts by mass of the resin having a functional group capable of reacting with an isocyanate group is preferably 3 parts by mass to 50 parts by mass, and more preferably 5 parts by mass to 40 parts by mass.

Crosslinking Agent The polyurethane in the present embodiment may be a polymer obtained by polymerizing a crosslinking agent as a hard segment component.
As a crosslinking agent, diol (bifunctional), triol (trifunctional), tetraol (tetrafunctional) etc. are mentioned, You may use these together. Moreover, you may use an amine compound as a crosslinking agent. In addition, it is desirable that it is bridge | crosslinked using the trifunctional or more than trifunctional crosslinking agent. Examples of the trifunctional crosslinking agent include trimethylolpropane, glycerin, triisopropanolamine and the like.

  The blending amount of the crosslinking agent with respect to 100 parts by mass of the resin having a functional group capable of reacting to the isocyanate group is preferably 2 parts by mass or less. When the amount is 2 parts by mass or less, the hard segment derived from the urethane bond is largely grown by aging without the molecular motion being constrained by chemical crosslinking, and the required hardness can be easily obtained.

  In the polyurethane of the present embodiment, it is preferable to use at least polyisocyanate and a chain extender as hard segment components, and further, use diphenylmethane diisocyanate (MDI) as the polyisocyanate and a straight chain having 3 or more carbon atoms as the chain extender. It is more preferred to use a chain diol.

The solubility parameter (SP value (H)) of the hard segment component is preferably in the range of 12.0 or more, more preferably in the range of 13.0 or more, and still more preferably in the range of 13.5 or more. By setting the above range, it becomes easy to control the value of ΔSP value (H−S) to the above range.
Further, the upper limit value is not particularly limited, but a range of 15.0 or less is preferable, a range of 14.5 or less is more preferable, and a range of 14.0 or less is more preferable. By setting the upper limit value to this range, a hard segment with high cohesion is easily formed, so high wear resistance can be obtained.

As a method of adjusting the SP value of the hard segment component (H phase), selection of polyisocyanate material, selection of kind of chain extender, adjustment of blending ratio of both when using polyisocyanate and chain extender, etc. Can be mentioned.
For example, by increasing the blending ratio of polyisocyanate (particularly MDI), the polarity increases and the SP value increases, and conversely, decreasing the blending ratio of polyisocyanate (especially MDI) decreases the polarity and the SP value decreases. Moreover, when using diol as a chain extender, the method of adjusting carbon number of this diol is mentioned, polarity is raised by decreasing carbon number of diol, SP value increases, conversely, polarity is raised by raising carbon number. Decreases and the SP value decreases.

Hard segment content ratio The mass ratio of the material constituting the hard segment to the total amount of hard segment material and soft segment material (hereinafter referred to as "hard segment material ratio") is in the range of 20% by mass to 45% by mass It is desirable to be present, and it is more desirable to be in the range of 30% by mass or more and 40% by mass or less.
When the hard segment material ratio is 20% by mass or more, abrasion resistance is obtained, and good cleanability is maintained for a long time. On the other hand, when the hard segment material ratio is 45% by mass or less, it does not become too hard, flexibility and extensibility are obtained, occurrence of chipping is suppressed, and good cleanability is maintained for a long time Be done.

-Molding method of polyurethane member (contact member) The general manufacturing method of polyurethane, such as prepolymer method and one shot method, is used for manufacture of polyurethane which constitutes the polyurethane member (contact member) in this embodiment. The prepolymer method is suitable for the present embodiment because a polyurethane excellent in strength and abrasion resistance is obtained, but it is not limited by the manufacturing method.
Such polyurethane is formed by blending polyisocyanate, a chain extender, a crosslinking agent and the like to the above-mentioned polyol.

The forming of the contact member of the cleaning blade is formed into a sheet by cutting the composition for forming the polyurethane member (contact member) prepared by the above method, for example, using centrifugal forming, extrusion forming, etc. It manufactures by giving a process etc.
For example, a composition for forming a polyurethane member (contact member) is poured into a mold of a centrifugal molding machine, and a curing reaction is caused. The mold temperature at this time is preferably 80 ° C. or more and 160 ° C. or less, and more preferably 100 ° C. or more and 140 ° C. or less. The reaction time is preferably 20 minutes or more and 3 hours or less, and more preferably 30 minutes or more and 2 hours or less.
Furthermore, it is aged, heated and cooled. The temperature of this aging heating is desirably 70 ° C. or more and 130 ° C. or less, more desirably 80 ° C. or more and 130 ° C. or less, and further desirably 100 ° C. or more and 120 ° C. or less. The reaction time is preferably 1 hour or more and 48 hours or less, and more preferably 10 hours or more and 24 hours or less.

The 100% modulus of the 100% modulus polyurethane member is preferably 6 MPa or more, more preferably 7 MPa or more, and still more preferably 7.5 MPa or more. On the other hand, as an upper limit of 100% modulus, 11 MPa or less is preferred, for example, and 10 MPa or less is more preferred.
When the 100% modulus is 6 MPa or more, an appropriate hardness is obtained and the wear resistance is excellent.

  Here, the 100% modulus is a value measured in accordance with J1 SK6251 (2004). That is, using a dumbbell-shaped No. 3 test piece, a stress-strain curve is obtained by measuring at a tensile speed of 500 mm / min (environmental temperature: 23 ° C.), and obtained based on this curve. In addition, as a measuring apparatus, a Toyo Seiki Co., Ltd. product and Strograph AE elastomer are used.

(Non-contact member)
Next, as in the second embodiment shown in FIG. 5 and the third embodiment shown in FIG. 6, the cleaning blade of this embodiment is made of different materials from the contact member and the region (non-contact member) other than the contact member. The composition of the non-contact member in the case where it is configured will be described.

  The non-contact member in the cleaning blade according to the present embodiment is not particularly limited, and any known material can be used.

  As a material used for a non-contact member, polyurethane, silicone rubber, fluororubber, chloropyrene rubber, butadiene rubber etc. are mentioned, for example. Among these, polyurethane is better. As a polyurethane, ester-type polyurethane and ether-type polyurethane are mentioned, Especially ester-type polyurethane is desirable.

In addition, when manufacturing polyurethane, there exists a method of using a polyol and polyisocyanate.
Examples of the polyol include polytetramethylene ether glycol (PTMG), polyethylene adipate and polycaprolactone.
As polyisocyanates, 2,6-toluene diisocyanate (TDI), 4,4'-diphenylmethane diisocyanate (MDI), paraphenylene diisocyanate (PPDI), 1,5-naphthalene diisocyanate (NDI), 3,3-dimethyldiphenyl- 4,4'-diisocyanate (TODI) etc. is mentioned. Among these, MDI is desirable.
Furthermore, as a curing agent for curing the polyurethane, curing agents such as 1,4-butanediol, trimethylolpropane, ethylene glycol and mixtures thereof can be mentioned.

  A specific example will be described by way of example. For example, a prepolymer formed by mixing diphenylmethane-4,4-diisocyanate with dehydrated polytetramethylether glycol and reacting it with 1,4-butadiol and trimethylolpropane as a curing agent It is desirable to use what was used together. In addition, you may add additives, such as reaction regulator.

  As a method for producing the noncontact member, a conventionally known method is used according to the raw material used for production, and for example, it is formed using centrifugal molding, extrusion molding, etc. and cut into a predetermined shape. It is made.

(Manufacturing of cleaning blade)
In the case of the cleaning blade consisting only of the contact member shown in FIG. 1, the cleaning blade is manufactured by the above-described method of molding the contact member.

  Further, in the case of the cleaning blade having a multi-layer structure such as the two-layer structure shown in FIG. 5, the first layer as the contact member and the second layer as the non-contact member A cleaning blade is manufactured by bonding a plurality of layers) to each other. A double-sided tape, various adhesives, etc. are used suitably as a method of bonding together. Alternatively, the layers may be adhered by pouring the materials of each layer into a mold with a time lag during molding and bonding the materials without providing an adhesive layer.

  Further, in the case of the configuration having the contact member (edge member) and the non-contact member (back member) shown in FIG. 6, a semi-cylindrical shape in which two contact members 3421C shown in FIG. The first mold having a cavity corresponding to the shape of (a region into which the composition for forming the contact member is poured), the contact member 3421C and the two noncontact members 3422C, and the shape in which the abdominal surface 3C sides are overlapped. Preparing a second mold having a cavity. A composition for forming a contact member is poured into the cavity of the first mold and cured to form a first molding having a shape in which two contact members 3421C are overlapped. Then, after the first mold is removed, the second mold is placed such that the first molding is placed inside the cavity of the second mold. Thereafter, a composition for forming a noncontact member is poured into the cavity of the second mold so as to cover the first molding and cured, and the two contact members 3421C and 3422C overlap with each other on the side of two belly faces 3C. Form a second molded product of the shape shown in FIG. Then, the formed second molded product is cut in the middle, that is, in a portion to be the abdominal surface 3C, and cut so that the semi-cylindrical contact member is divided in the middle and becomes a cylindrical shape cut into 1/4. By further cutting to a predetermined size, the cleaning blade shown in FIG. 6 is obtained.

-Application When cleaning a member to be cleaned using the cleaning blade of this embodiment, the member to be cleaned is not particularly limited as long as the member is required to clean the surface. For example, if it is used in an image forming apparatus, the toner is further removed from the intermediate transfer body, the charging roll, the transfer roll, the transfer material conveying belt, the sheet conveying roll, and the cleaning brush for removing the toner from the image holder. A detoning role etc. are also mentioned. In the present embodiment, an image carrier is particularly desirable.

(Cleaning device, process cartridge and image forming apparatus)
Next, a cleaning device, a process cartridge, and an image forming apparatus using the cleaning blade of this embodiment will be described.
The cleaning device of the present embodiment is not particularly limited as long as it has the cleaning blade of the present embodiment as a cleaning blade that contacts the surface of the member to be cleaned and cleans the surface of the member to be cleaned. For example, as a configuration example of the cleaning device, the cleaning blade is fixed in a cleaning case having an opening on the side of the member to be cleaned such that the edge tip is on the side of the opening, and is recovered from the surface of the member to be cleaned by the cleaning blade. There is a configuration provided with a transport member for guiding foreign substances such as waste toner to the foreign substance recovery container. Further, two or more cleaning blades of the present embodiment may be used in the cleaning device of the present embodiment.

When the cleaning blade of this embodiment is used to clean the image carrier, the force NF (Normal Force) with which the cleaning blade is pressed against the image carrier is 1 in order to suppress the image flow at the time of image formation. It is preferably in the range of not less than 3 gf / mm and not more than 2.3 gf / mm, and more preferably in the range of not less than 1.6 gf / mm and not more than 2.0 gf / mm.
The length at which the cleaning blade tip bites into the image carrier is preferably in the range of 0.8 mm to 1.2 mm, and more preferably in the range of 0.9 mm to 1.1 mm.
The angle W / A (Working Angle) at the contact portion between the cleaning blade and the image carrier is preferably in the range of 8 ° to 14 °, and more preferably in the range of 10 ° to 12 °.

  On the other hand, the process cartridge of the present embodiment is equipped with the cleaning device of the present embodiment as a cleaning device that contacts the surface of one or more members to be cleaned such as an image carrier and an intermediate transfer member to clean the surface of the member to be cleaned. It is not particularly limited as long as it is an image carrier, and includes, for example, an aspect including an image carrier and the cleaning device of the present embodiment for cleaning the surface of the image carrier, which is detachable with respect to the image forming apparatus. For example, in the case of a so-called tandem machine having an image carrier corresponding to each color toner, the cleaning device of the present embodiment may be provided for each image carrier. In addition to the cleaning device of this embodiment, a cleaning brush or the like may be used in combination.

-Specific examples of cleaning blade, image forming apparatus and cleaning device-
Next, specific examples of the cleaning blade according to the present embodiment and the image forming apparatus and the cleaning apparatus using the same will be described in more detail with reference to the drawings.
FIG. 3 is a schematic view showing an example of the image forming apparatus of the present embodiment, and shows a so-called tandem type image forming apparatus.
In FIG. 3, 21 is a main body housing, 22 and 22a to 22d are imaging units, 23 is a belt module, 24 is a recording medium supply cassette, 25 is a recording medium conveyance path, 30 is each photosensitive unit, and 31 is a photosensitive drum. 33 is a developing unit, 34 is a cleaning device, 35, 35a to 35d is a toner cartridge, 40 is an exposure unit, 41 is a unit case, 42 is a polygon mirror, 51 is a primary transfer device, 52 is a secondary transfer device, 53 Is a belt cleaning device, 61 is a delivery roll, 62 is a transport roll, 63 is an alignment roll, 66 is a fixing device, 67 is a delivery roll, 68 is a delivery unit, 71 is a manual feeding device, 72 is a delivery roll, 73 is a unit for duplex recording, 74 is a guide roll, 76 is a transport path, 77 is a transport roll, 230 is an intermediate transfer belt, 23 , 232 support roll, 521 secondary transfer roll, 531 denotes a cleaning blade.

  The tandem type image forming apparatus shown in FIG. 3 arranges image forming units 22 (specifically, 22a to 22d) of four colors (in this embodiment, yellow, magenta, cyan, black) in a main body housing 21. Above that, a belt module 23 including an intermediate transfer belt 230 which is circularly transported along the arrangement direction of the image forming units 22 is disposed, while a recording medium such as a sheet of paper (see FIG. A recording medium supply cassette 24 containing a not shown member is disposed, and a recording medium conveyance path 25 serving as a conveyance path of the recording medium from the recording medium supply cassette 24 is disposed in the vertical direction.

In the present embodiment, each of the image forming units 22 (22a to 22d) is sequentially arranged, for example, for yellow, magenta, cyan, and black from the upstream side of the intermediate transfer belt 230 in the circulation direction. The present invention is not limited to this, and forms a toner image, and includes each photosensitive unit 30, each developing unit 33, and one common exposure unit.
Here, the photosensitive unit 30 includes, for example, a photosensitive drum 31, a charging device (charging roll) 32 for charging the photosensitive drum 31 in advance, and a cleaning device 34 for removing residual toner on the photosensitive drum 31. It is integrated into a sub-cartridge.

The developing unit 33 develops the electrostatic latent image exposed and formed by the exposure unit 40 on the charged photosensitive drum 31 with a corresponding color toner (for example, negative polarity in the present embodiment). For example, a process cartridge (so-called Customer Replaceable Unit) is configured by being integrated with a sub-cartridge formed of the photosensitive unit 30, for example.
Of course, the photosensitive unit 30 may be separated from the developing unit 33 to form a single process cartridge. Further, in FIG. 3, reference numerals 35 (35a to 35d) denote toner cartridges for replenishing the respective color component toners to the respective developing units 33 (a toner replenishment path is not shown).

  On the other hand, the exposure unit 40 includes, for example, four semiconductor lasers (not shown), one polygon mirror 42, an imaging lens (not shown), and mirrors (FIG. (Not shown), the light from the semiconductor laser for each color component is deflected and scanned by the polygon mirror 42, and arranged so as to guide the light image to the exposure point on the corresponding photosensitive drum 31 via the imaging lens and mirror. It is

  Further, in the present embodiment, the belt module 23 is, for example, one in which the intermediate transfer belt 230 is stretched between a pair of support rolls (one is a drive roll) 231 and 232. A primary transfer device (in this example, a primary transfer roll) 51 is disposed on the back surface of the intermediate transfer belt 230 corresponding to 31. By applying a voltage having a reverse polarity to the charging polarity of toner to the primary transfer device 51, The toner image on the photosensitive drum 31 is electrostatically transferred to the intermediate transfer belt 230 side. Further, a secondary transfer device 52 is disposed at a portion corresponding to the support roll 232 on the downstream side of the most downstream imaging unit 22d of the intermediate transfer belt 230, and the primary transfer image on the intermediate transfer belt 230 is recorded as a recording medium. Secondary transfer (batch transfer).

In the present embodiment, the secondary transfer device 52 includes a secondary transfer roll 521 disposed in pressure contact with the toner image holding surface side of the intermediate transfer belt 230 and a secondary transfer roll disposed on the back side of the intermediate transfer belt 230. And a back surface roll (in this example, also used as a support roll 232) forming an opposing electrode 521. For example, the secondary transfer roll 521 is grounded, and a bias having the same polarity as the charging polarity of the toner is applied to the back roll (support roll 232).
Further, a belt cleaning device 53 is disposed on the upstream side of the most upstream image forming unit 22 a of the intermediate transfer belt 230, and removes the residual toner on the intermediate transfer belt 230.

  Further, the recording medium supply cassette 24 is provided with a delivery roll 61 for delivering the recording medium, and immediately after the delivery roll 61, a transport roll 62 for delivering the recording medium is provided. In the recording medium transport path 25 positioned immediately before, a positioning roll 63 for supplying the recording medium to the secondary transfer site at a predetermined timing is disposed. On the other hand, a fixing device 66 is provided in the recording medium transport path 25 located downstream of the secondary transfer site, and a discharge roll 67 for discharging the recording medium is provided downstream of the fixing device 66. A discharged recording medium is accommodated in a discharge unit 68 formed in the upper portion of the housing 21.

Furthermore, in the present embodiment, a manual feeding device 71 is provided on the side of the main body housing 21, and the recording medium on the manual feeding device 71 is fed by the delivery roll 72 and the transport roll 62. It is sent out to 25.
Furthermore, a double-sided recording unit 73 is attached to the main housing 21. The double-sided recording unit 73 discharges the recording medium on which single-sided recording has been performed when selecting the double-sided mode for recording images on both sides of the recording medium. 67 is reversed, and introduced inside by the guide roll 74 in front of the entrance, and the recording medium is conveyed by the conveyance roll 77 along the recording medium return conveyance path 76 inside, and is supplied again to the alignment roll 63 side. It is

Next, the cleaning device 34 disposed in the tandem type image forming apparatus shown in FIG. 3 will be described in detail.
FIG. 4 is a schematic cross-sectional view showing an example of the cleaning device of the present embodiment, and also shows the photosensitive drum 31, the charging roll 32, and the developing unit 33 which are made into subcartridges together with the cleaning device 34 shown in FIG. FIG.
In FIG. 4, 32 is a charging roll (charging device), 331 is a unit case, 332 is a developing roll, 333 is a toner conveying member, 334 is a conveying paddle, 335 is a developer layer thickness regulating member, 341 is a cleaning case, 342 is a cleaning case. A cleaning blade 344 is a film seal, and 345 is a transport member.

  The cleaning device 34 has a cleaning case 341 which contains residual toner and which is opened opposite to the photosensitive drum 31, and a cleaning blade 342 disposed in contact with the photosensitive drum 31 at the lower edge of the opening of the cleaning case 341. Is attached via a bracket (not shown), while a film seal 344 is attached to the opening upper edge of the cleaning case 341 so as to keep the space between the photosensitive drum 31 airtight. Reference numeral 345 denotes a conveying member for guiding the waste toner stored in the cleaning case 341 to the side waste toner container.

  In the present embodiment, the cleaning blade of the present embodiment is used as the cleaning blade 342 in all the cleaning devices 34 of each of the image forming units 22 (22a to 22d). The cleaning blade of this embodiment may also be used as the cleaning blade 531.

Further, the developing unit (developing device) 33 used in the present embodiment, for example, as shown in FIG. 4, has a unit case 331 which contains a developer and which is open facing the photosensitive drum 31. Here, the developing roll 332 is disposed at a location facing the opening of the unit case 331, and a toner conveyance member 333 for developer agitation and conveyance is disposed in the unit case 331. Furthermore, a conveyance paddle 334 may be disposed between the developing roll 332 and the toner conveyance member 333.
At the time of development, after the developer is supplied to the developing roll 332, the developer is transported to the developing region facing the photosensitive drum 31 in a state where the layer thickness of the developer is regulated by the developer layer thickness regulating member 335, for example.

  In the present embodiment, for example, a two-component developer consisting of toner and carrier is used as the developing unit 33, but a one-component developer consisting only of toner may be used.

Next, the operation of the image forming apparatus according to the present embodiment will be described. First, when each image forming unit 22 (22a to 22d) forms a single color toner image corresponding to each color, the single color toner image of each color is sequentially superimposed on the surface of the intermediate transfer belt 230 so as to coincide with the original document information. Transcribed. Subsequently, the color toner image transferred onto the surface of the intermediate transfer belt 230 is transferred onto the surface of the recording medium by the secondary transfer device 52, and the recording medium onto which the color toner image is transferred is subjected to fixing processing by the fixing device 66. , And the sheet is discharged to the sheet discharge unit 68.
On the other hand, in each image forming unit 22 (22a to 22d), the residual toner on the photosensitive drum 31 is cleaned by the cleaning device 34, and the residual toner on the intermediate transfer belt 230 is cleaned by the belt cleaning device 53. Ru.
In such an imaging process, each residual toner is cleaned by the cleaning device 34 (or the belt cleaning device 53).

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

  EXAMPLES The present invention will be described below by way of Examples, but the present invention is not limited to these Examples.

Example 1
-Cleaning blade A1-
· Prepolymerization of polyol: Adipic acid (HOOC-C ₄ H ₈ -COOH) and nonane diol (HO-C ₉ H ₁₈ -OH) are polymerized at 1: 1 (molar ratio) and terminal is -OH The resultant was processed to obtain a polyester polyol A1 in which a linear diol having 9 carbon atoms (nonanediol) was polymerized. The weight average molecular weight of the obtained polyester polyol A1 was 2,000.

Preparation of Cleaning Blade: Using the polyester polyol A1 as a soft segment component, propanediol (chain extender) and 4,4'-diphenylmethane diisocyanate (MDI, polyisocyanate, Nippon Polyurethane Industry Co., Ltd., Millionate MT) And a crosslinking agent (trimethylolpropane, manufactured by Mitsubishi Gas Chemical Co., Ltd.) as a hard segment component, and adjust the compounding amount to the molar ratio described in Table 1 below, and react at 80 ° C. for 2 hours under a nitrogen atmosphere The composition for forming a cleaning blade A1 was prepared.

  Subsequently, the composition A1 for forming a cleaning blade was poured into a centrifugal molding machine whose mold was adjusted to 140 ° C., and curing reaction was performed for 1 hour. Subsequently, aging heating was carried out at 110 ° C. for 24 hours, followed by cooling and cutting to obtain a cleaning blade A1 having a width of 8 mm and a thickness of 2 mm.

Example 2
By the method described in Example 1 except that the composition used for prepolymerization of the polyol, the polyol, the chain extender, the polyisocyanate, the type of the crosslinking agent and the compounding amount thereof are changed to those described in Table 1 below. A composition for forming a cleaning blade was prepared, and a cleaning blade was obtained.

[Example 3]
By the method described in Example 1 except that the composition used for prepolymerization of the polyol, the polyol, the chain extender, the polyisocyanate, the type of the crosslinking agent and the compounding amount thereof are changed to those described in Table 1 below. A composition for forming a cleaning blade was prepared, and a cleaning blade was obtained.

Comparative Example 1
By the method described in Example 1 except that the composition used for prepolymerization of the polyol, the polyol, the chain extender, the polyisocyanate, the type of the crosslinking agent and the amount thereof are changed to those described in Table 2 below. A composition for forming a cleaning blade was prepared, and a cleaning blade was obtained.

Comparative Example 2
By the method described in Example 1 except that the composition used for prepolymerization of the polyol, the polyol, the chain extender, the polyisocyanate, the type of the crosslinking agent and the amount thereof are changed to those described in Table 2 below. A composition for forming a cleaning blade was prepared, and a cleaning blade was obtained.

Comparative Example 3
By the method described in Example 1 except that the composition used for prepolymerization of the polyol, the polyol, the chain extender, the polyisocyanate, the type of the crosslinking agent and the amount thereof are changed to those described in Table 2 below. A composition for forming a cleaning blade was prepared, and a cleaning blade was obtained.

<Measurement of edge permanent deformation>
A process cartridge in which the cleaning blade of each of the above-mentioned examples is attached to a surface of a photosensitive member (image carrier) by biting in contact with it is used as a constant temperature / humidity layer in a high temperature / high humidity environment (45 ° C., 95% RH) It was left to stand for one week, and the difference between the biting amount of the cleaning blade before and after leaving was taken as the amount of permanent deformation.
The amount of bite is measured using a non-contact laser displacement meter (trade name: LK-035, manufactured by Keyence Corporation) capable of measuring the distance from the center of the photosensitive member to the edge of the edge of the cleaning blade. Asked for a change in

<Image evaluation>
(Configuration of image forming apparatus)
The cleaning blade of each example was mounted as a cleaning blade for a photosensitive drum in an image forming apparatus (manufactured by Fuji Xerox Co., Ltd., trade name: DocuCentre-II C7500) shown in FIG.
Photosensitive drum: Organic photosensitive material (φ = 30 mm)
Process speed: 250 mm / sec
Charging device: AC superimposed DC charging roller Developing device: Two-component magnetic brush developing device Cleaning blade: Width 8 mm, thickness 2 mm, free length 7.0 mm, contact angle 25 degrees, pressing force NF 2.0 gf / mm

In the test, using a toner (a toner manufactured by a polymerization method and distributed in a shape factor of 123 to 128 and having an average particle diameter of 6 μm), a two-component developer containing this toner is used as a developing device in the above image forming apparatus. Contained and used. The image of the test print (area ratio 5% per color) by this image forming apparatus was repeated for five sheets for the number of prints of 50,000 sheets in each environment described below. In addition, as a stress environment, process speed: 250 mm / sec, high temperature and high humidity (32.5 ° C., 85% RH), low temperature and low humidity (5 ° C., 15% RH), and medium temperature and medium humidity (22 ° C., 55% RH) And
-Abrasion resistance evaluation-
The abrasion resistance of the cleaning blade was evaluated by the following method.
A4 paper (210 x 297 mm, Fuji Xerox Co., Ltd., P paper) until the cumulative number of revolutions of the photosensitive member reaches 100 K cycles (100,000 rotations) under high temperature and high humidity environment (32.5 ° C, 85RH%) The image was formed using Thereafter, the wear depth of the contact portion (edge) of the cleaning blade and the cleaning failure were evaluated together to determine edge wear. In the test, the image density of the image to be formed is set to 1% in order to evaluate under severe conditions in which the lubricating effect at the contact portion between the photosensitive member and the cleaning blade is reduced. Further, the wear depth of the edge tip was taken as the maximum depth of the edge missing portion on the photoreceptor surface side, which was confirmed when observed from a cross section side of the cleaning blade with a laser microscope VK-8510 manufactured by Keyence Corporation.
The evaluation criteria of edge wear are shown below. The allowable range is A and B.
A: Tip wear depth: 3 μm or less and no wear marks Poor cleaning: Not generated B: Tip wear depth: More than 3 μm, 5 μm or less Cleaning failure: Not occurred C: Tip wear depth: More than 5 μm Cleaning Bad: Occurred

-Image quality evaluation-
The cleaning blade of each of the above examples was mounted as a cleaning blade for a photosensitive drum in a color copying machine (DocuCentre Color a 450, manufactured by Fuji Xerox Co., Ltd.).
Using this color copying machine, 2000 sheets of image formation on an image density of 1% (A4 size paper with a solid image of 6.2 mm × 1 mm on it) were repeated on a paper (C2r paper made by Fuji Xerox Co., Ltd.) . The degree of deformation of the cleaning blade after that and the occurrence of image quality defects of color stripes were visually evaluated according to the following criteria.
A: A color stripe is not confirmed B: A color stripe is slightly confirmed in the image, but is within an acceptable range C: A color stripe is confirmed in the image, which is unacceptable

  Further, Examples and Comparative Examples will be shown for a cleaning blade using polytetramethylene ether glycol (PTMG) as a polyol.

Example 4
A composition for forming a cleaning blade is prepared by the method described in Example 1 except that the types of polyol, chain extender, polyisocyanate, and crosslinking agent and the blending amount thereof are changed to those described in Table 3 below, And got a cleaning blade.

Comparative Example 4
A composition for forming a cleaning blade is prepared by the method described in Example 1 except that the types of polyol, chain extender, polyisocyanate, and crosslinking agent and the blending amount thereof are changed to those described in Table 3 below, And got a cleaning blade.

Here, the details of the compounds described in Tables 1 to 3 will be described.
-PTMG: polytetramethylene ether glycol (manufactured by Hodogaya Chemical Industry Co., Ltd., PTG 2000 SN, molecular weight 2000)
MDI: 4,4'-diphenylmethane diisocyanate caprolactone: polycaprolactone polyol (made by Daicel Co., Ltd., Plaxel 220 N, average molecular weight 2000)

In the embodiment, by using a urethane member having a ΔSP value (H−S) of 4.0 or more and 5.5 or less, a permanent blade is small, a good cleaning property is achieved over a long period, and a cleaning blade excellent in image performance. Is obtained.
In Comparative Example 1, ΔSP (H−S) exceeds 5.5, the abrasion resistance is deteriorated, and a good image is not obtained.
In Comparative Example 2, ΔSP (H−S) is less than 4.0, the permanent deformation is large, and a good image is not obtained.
In Comparative Example 3, ΔSP (H−S) is less than 4.0, the permanent deformation is large, and a good image is not obtained.
In Comparative Example 4, ΔSP (H−S) is less than 4.0, the permanent deformation is large, and a good image is not obtained.

3A contact angle portion, 3B tip surface, 3C abdominal surface, 3D rear surface, 21 main body housing, 22, 22a to 22d image forming unit, 23 belt module, 24 recording medium supply cassette, 25 recording medium conveyance path, 30 photoconductor unit, 31 To-be-cleaned member (image carrier / photosensitive drum), 32 charging rolls, 33 developing units, 34 cleaning devices, 35, 35a to 35d toner cartridges, 40 exposure units, 41 unit cases, 42 polygon mirrors, 51 primary transfer devices, 52 secondary transfer device, 53 belt cleaning device, 61 delivery roller, 62 conveyance roller, 63 alignment roller, 66 fixing device, 67 discharge roller, 68 delivery unit, 71 manual feed device, 72 delivery roller, 73 both sides Recording unit, 74 guide rolls, 76 transports , 77 conveying rolls, 230 intermediate transfer belts, 231, 232 supporting rolls, 331 unit cases, 332 developing rolls, 333 toner conveying members, 334 conveying paddles, 335 developer layer thickness regulating members, 341 cleaning cases, 342, 342A, 342B , 342C cleaning blade, 344 film seal, 345 conveying member, 521 secondary transfer roll, 531 cleaning blade, 3421B first layer, 3422B second layer, 3421C contact member, 3422C back member

Claims (7)

  The absolute value (ΔSP value (H) of the difference between the solubility parameter (SP value (H)) of the hard segment component and the solubility parameter (SP value (S)) of the soft segment component including a hard segment component and a soft segment component A cleaning blade in which at least a contact portion in contact with the member to be cleaned is formed of a polyurethane member containing polyurethane having a S of 4.0 or more and 5.5 or less.   The cleaning according to claim 1, wherein the solubility parameter (SP value (S)) of the soft segment component is 10.5 or less, and the solubility parameter (SP value (H)) of the hard segment component is 12.0 or more. blade.   The cleaning blade according to claim 1 or 2, wherein the polyurethane is a resin in which diphenylmethane diisocyanate (MDI) and a linear diol having 3 or more carbon atoms are at least polymerized as the hard segment component.   In the polyurethane, at least one polyol selected from the group consisting of a polyether polyol and a polyester polyol obtained by polymerizing at least a linear diol having 9 or more carbon atoms is polymerized as the soft segment component. The cleaning blade according to any one of claims 1 to 3, which is a resin.   A cleaning device comprising the cleaning blade according to any one of claims 1 to 4.   A process cartridge comprising the cleaning device according to claim 5 and removable with respect to an image forming apparatus. An image carrier,
Charging means for charging the surface of the image carrier;
Electrostatic latent image forming means for forming an electrostatic latent image on the surface of the charged image carrier;
Developing means for developing the electrostatic latent image formed on the surface of the image carrier with a developer containing toner to form a toner image;
A transfer unit that transfers the toner image to the surface of a recording medium;
A cleaning device comprising the cleaning device according to claim 5, wherein the cleaning blade is brought into contact with the image carrier to clean the surface of the image carrier.
An image forming apparatus comprising: