JP4931726B2 - Cleaning blade, and image forming method, image forming apparatus, and process cartridge using the same - Google Patents

Description

  INDUSTRIAL APPLICABILITY The present invention is suitable for an image forming apparatus using an electrophotographic system such as a copying machine, a facsimile machine, and a printer, exhibits high wear resistance, can achieve good cleaning properties even in a low temperature environment, has a long life and high The present invention relates to a cleaning blade having reliability, an image forming method using the cleaning blade, an image forming apparatus, and a process cartridge.

  Conventionally, in an electrophotographic system, the surface of an electrostatic latent image carrier (hereinafter also referred to as “electrophotographic photosensitive member”, “photosensitive member”, or “latent image carrier”) is charged and exposed to light. The developed electrostatic latent image is developed with toner to form a visible toner image, the toner image is transferred to a recording medium such as transfer paper, and is heated and pressed to be fixed on the recording medium. An image is formed. Since the untransferred toner remains on the surface of the latent electrostatic image bearing member after the transfer of the toner image, the residual toner can be removed using a cleaning unit prior to the next image forming process. I need it. By this cleaning means, foreign matters other than the toner adhering to the surface of the electrostatic latent image carrier are also removed together with the residual toner.

  As cleaning means for removing such residual toner after transfer, there are various methods such as a method using a fur brush, a magnetic brush or the like, and a method using a rubber blade. Among these, a cleaning means that scrapes off the residual toner by rubbing the surface of the electrostatic latent image carrier with a rubber blade made of an elastic material is widely used from a balance of cost and performance. As the material of the rubber blade, polyurethane rubber having excellent wear resistance is generally used.

2. Description of the Related Art In recent years, image quality has been improved in an electrophotographic image forming apparatus, and as one direction for achieving the higher image quality, toner diameter and spheroidization have been promoted. By reducing the diameter, it is possible to improve the reproducibility of the dots of the toner image formed on the surface of the electrostatic latent image carrier, and it is possible to improve the developability and transferability by making it spherical.
However, when such a small-diameter and spherical toner is used, the blade cleaning method using a rubber blade has a problem that good cleaning performance cannot be obtained. In the cleaning method using a rubber blade, since the untransferred toner is scraped off by sliding the rubber blade against the surface of the electrostatic latent image carrier, the surface of the electrostatic latent image carrier and the rubber blade The tip of the edge of the rubber blade is deformed by the frictional resistance, and a minute wedge-shaped space is formed between them. In this space, the smaller the diameter of the toner, the easier it is to enter the edge tip, and the toner that has entered the edge tip is less likely to be replaced, creating a region where the toner does not flow. The frictional resistance between the toner in the non-flowing region and the electrostatic latent image carrier is relatively small, and the cleaning performance is not impaired when the toner slides against the electrostatic latent image carrier. When the external additive is removed by rubbing with the carrier and the frictional force between the toner and the electrostatic latent image carrier increases, the rolling friction of the spherical toner is smaller than that of the irregular toner of the conventional pulverization method. It is considered that rolling starts between the blade and the electrostatic latent image carrier and slips through.
In addition, when the toner is spherical and has a sharp particle size distribution, it is easier to close-pack than an irregular toner. It is considered that the toner is easily compacted, the frictional force between the electrostatic latent image carrier and the toner increases, and the toner is likely to roll. Furthermore, since the charge amount of the toner becomes high under a low temperature environment, it is considered that the adhesion between the electrostatic latent image carrier and the toner increases, and the rolling of the toner is accelerated.

  Also, in the blade cleaning system, the glass transition temperature (Tg) of polyurethane rubber, which is the main constituent material, is near room temperature, so it shows a glass state in a low-temperature and low-humidity environment. The reality is that the decline in sex is inevitable. For this reason, if the contact pressure of the rubber blade to the surface of the electrostatic latent image carrier is increased, the cleaning property is improved. However, when the contact pressure is high, the electrostatic latent latent image carrier is used in a high temperature and high humidity environment. The adhesion force between the image carrier and the rubber blade increases, and the amount of deformation of the blade tip increases. As a result, the blade edge may be chipped or the cleaning blade may be swollen. When spherical toner is used in this way, and in order to obtain good cleaning properties that are stable for a long period of time in any environment, it is required to strictly adjust the rubber properties of the cleaning blade and the setting conditions for mounting the blade. Moreover, it is extremely difficult to balance that.

Therefore, in an image forming apparatus using spherical toner, a method of forming an image using a toner obtained by mixing spherical toner and irregular toner has been proposed in order to prevent cleaning failure of the cleaning blade (Patent Document 1). And Patent Document 2). However, in these methods, a mixture of spherical toner and irregular toner is used as a toner for development, so a dense and uniform image compared with the case where only spherical toner is developed, or spherical toner There is a problem that high transfer efficiency which is an advantage of the above cannot be obtained.
Further, as another means for preventing a cleaning failure of a cleaning blade in an image forming apparatus using spherical toner, a method of supplying a lubricant or the like to an electrostatic latent image carrier has been proposed (see Patent Document 3). However, in this proposal, if the supply of the lubricant to the electrostatic latent image carrier is insufficient, a cleaning failure occurs.If the supply is excessive, adverse effects due to adhesion to the electrostatic latent image carrier are likely to occur. Therefore, it is necessary to supply the electrostatic latent image carrier uniformly over the entire surface, which is very difficult to design.
In recent years, the size of image forming apparatuses has been reduced, and in an image forming apparatus using a small-diameter electrostatic latent image carrier, a lubricant supply device that directly supplies lubricant to the surface of the electrostatic latent image carrier. It is very difficult to secure space. In particular, a tandem image forming apparatus is extremely disadvantageous in terms of cost reduction because it is necessary to provide each electrostatic latent image carrier with a lubricant supply device.

  Recently, for the purpose of improving the cleaning property in a low temperature environment, a method of using a polyurethane elastomer in which a siloxane chain is uniformly dispersed by using polypropylene glycol as a compatibilizing agent has been proposed (see Patent Document 4). . According to this proposal, a cleaning blade having high durability and low temperature dependence of physical properties can be obtained by incorporating a polydimethylsiloxane chain having excellent low-temperature characteristics into a urethane bond having excellent wear resistance. However, in this proposal, since the urethane bond and the siloxane chain exist in a state of being uniformly mixed, the effect of the characteristics derived from the respective chemical structures is halved. Specifically, the abrasion resistance is lower than that of a polyurethane elastomer cleaning blade made of only urethane bonds, and the low temperature characteristics are inferior to that of a cleaning blade made of only a siloxane elastomer. The current situation is that it cannot be said.

JP-A-60-131547 Japanese Patent Laid-Open No. 6-148941 Japanese Patent Laid-Open No. 5-188443 JP 2000-29307 A

  An object of the present invention is to solve various problems in the prior art and achieve the following objects. That is, the present invention provides a cleaning blade having a good cleaning property even when using a toner having a small particle size and a spherical shape and in a low temperature environment, exhibiting high wear resistance, and having a long life and high reliability. It is another object of the present invention to provide an image forming method, an image forming apparatus, and a process cartridge using the cleaning blade.

Means for solving the problems are as follows. That is,
<1> A cleaning blade for removing toner remaining on the surface of the electrostatic latent image carrier,
The cleaning blade contains a polyurethane elastomer, and the polyurethane elastomer contains a diol (A) having a number average molecular weight of 1,000 to 5,000, a diisocyanate (B), and two or more hydrolyzable alkoxy groups. A cleaning blade obtained by reacting polysiloxane (C) having an acid generator (D).
<2> The cleaning blade according to <1>, wherein the polysiloxane (C) is at least one condensate of a silane compound having a hydrolyzable alkoxy group represented by the following general formula (1).
R ¹ _m Si (OR ² ) _4-m ... General formula (1)
In the general formula (1), R ¹ represents any of saturated aliphatic hydrocarbon group and aromatic hydrocarbon group having 1 to 12 carbon atoms. R ² represents an alkyl group having 1 to 4 carbon atoms. m is an integer of 0-2.
<3> The cleaning blade according to any one of <1> to <2>, wherein the polysiloxane (C) has a number average molecular weight of 500 to 6,000.
<4> The cleaning blade according to any one of <1> to <3>, wherein the content of the polysiloxane (C) is 5% by mass to 30% by mass with respect to the solid mass of the polyurethane elastomer.
<5> An electrostatic latent image forming step of forming an electrostatic latent image on the electrostatic latent image carrier, a developing step of developing the electrostatic latent image with toner to form a visible image, Image formation including at least a transfer step of transferring a visible image to a recording medium, a fixing step of fixing the transferred image transferred to the recording medium, and a cleaning step of removing residual toner on the surface of the electrostatic latent image carrier A method,
In the image forming method, the cleaning step is performed using the cleaning blade according to any one of <1> to <4>.
<6> An electrostatic latent image carrier, electrostatic latent image forming means for forming an electrostatic latent image on the electrostatic latent image carrier, and developing the electrostatic latent image with toner to make it visible Developing means for forming an image, transfer means for transferring the visible image to a recording medium, fixing means for fixing the transferred image transferred to the recording medium, and residual toner on the surface of the electrostatic latent image carrier An image forming apparatus having at least a cleaning unit
An image forming apparatus, wherein the cleaning unit includes the cleaning blade according to any one of <1> to <4>.
<7> An electrostatic latent image carrier, development means for developing the electrostatic latent image formed on the electrostatic latent image carrier with toner to form a visible image, and the surface of the electrostatic latent image carrier A process cartridge having at least a cleaning means for removing the residual toner,
The process cartridge includes the cleaning blade according to any one of <1> to <4>.

The cleaning blade of the present invention comprises a polyurethane elastomer, and the polyurethane elastomer comprises a diol (A) having a number average molecular weight of 1,000 to 5,000, a diisocyanate (B), and two or more hydrolyzable substances. Since the polysiloxane (C) having an alkoxy group is reacted with the acid generator (D), it is possible to suppress the abrasion of the cleaning blade and the chipping of the edge region over time, and cleaning is also performed in a low temperature environment. Since fluctuations in the physical properties of the blade are suppressed, good cleaning characteristics can be exhibited, and a long-life and highly reliable cleaning blade can be provided.
The reason is that the urethane segment of the polyurethane elastomer and the polysiloxane segment are microscopically phase-separated. From this observation result in a minute region using an electron microscope, a sea-island structure having a size of several tens of nanometers is observed, and each of these states is considered to correspond to a urethane segment and a polysiloxane segment. In other words, each segment is not uniformly compatible, and the domain is formed so that each feature can be maintained in a minute region, and the features derived from each molecular structure are not impaired. Thus, it is possible to achieve both the wear resistance and the low glass transition point and the high elasticity characteristic of the siloxane structure. Further, when viewed macroscopically as in visual observation, a transparent elastomer is obtained, and the compatibility of the constituent materials is not necessarily poor. It is presumed that phase separation at the molecular level can achieve both good durability and good cleanability in a low temperature environment.
Accordingly, the cleaning blade for removing the toner remaining on the surface of the electrostatic latent image carrier has a diol (A) having a number average molecular weight of 1,000 to 5,000, a diisocyanate (B), and two or more hydrolyzable alkoxy compounds. Since it contains a polyurethane elastomer obtained by reacting a polysiloxane (C) having a group with an acid generator (D), both high wear resistance and improvement in cleanability in a low temperature environment can be achieved. Even when a toner having a particle size and a spherical shape is used, high-quality image output can be realized over a long period of time.

  According to the present invention, various problems in the prior art can be solved, and when a toner having a small particle size and a spherical shape is used, and also in a low temperature environment, it has a good cleaning property, exhibits high wear resistance, and is long. A cleaning blade having a long life and high reliability, and an image forming method, an image forming apparatus, and a process cartridge using the cleaning blade can be provided.

(Cleaning blade)
The cleaning blade of the present invention is arranged to be in contact with an electrostatic latent image carrier such as a drum or endless belt that carries a toner image on its surface and is carried by the electrostatic latent image carrier. After the toner image is transferred to a recording medium such as paper or an intermediate transfer medium such as an endless belt, the transfer residual toner remaining on the surface of the electrostatic latent image carrier is removed.

If the said cleaning blade is a rubber blade containing the polyurethane elastomer demonstrated in detail below, there will be no restriction | limiting in particular in the shape, a structure, a magnitude | size, and it can select suitably according to the objective.
Examples of the shape of the contact surface of the cleaning blade include a flat surface, a curved surface, a fine uneven surface, a fine hole surface, and a linear groove surface. Examples of the tip shape of the cleaning blade include a planar shape and a curved surface shape. Examples of the overall shape of the cleaning blade include a rectangular plate shape.
Examples of the general structure of the cleaning blade include those formed by one type of member and those formed by two or more types of members. In the latter case, a combination of a support member and a rubber blade can be used, and at least the member in contact with the electrostatic latent image carrier is a rubber blade containing a polyurethane elastomer described below.

The cleaning blade of the present invention comprises at least a polyurethane elastomer,
The polyurethane elastomer comprises a diol (A) having a number average molecular weight of 1,000 to 5,000, a diisocyanate (B), a polysiloxane (C) having two or more hydrolyzable alkoxy groups, an acid generator ( D) is preferably obtained by reacting a chain extender (E), a catalyst, and, if necessary, other components.

-Diol (A) having a number average molecular weight of 1,000 to 5,000-
Examples of the diol (A) having a number average molecular weight (Mn) of 1,000 to 5,000 include polyester diol (A1) and polyester diol (A2). These may be used individually by 1 type and may use 2 or more types together.

As the polyether diol (A1), for example, a low molecular diol, a compound containing two hydroxyl groups such as divalent phenols, an alkylene oxide having 2 to 5 carbon atoms (hereinafter sometimes abbreviated as AO) is used. Examples of the compound include a block or a random addition. Among these, those obtained by adding AO to a low molecular diol are preferable, and polytetramethylene glycol (PTMG) obtained by adding 1,4-butylene oxide to an aliphatic diol is particularly preferable.
As the polyester diol (A2), a condensation polymer of a low molecular diol and a dicarboxylic acid or an ester-forming derivative thereof [eg, acid anhydride, lower alkyl (carbon number 1 to 4) ester, acid halide, etc.]; low Examples thereof include a ring-opening polymer of a lactone monomer using a molecular diol as an initiator; a mixture of two or more of these.
Among these diols (A), polyether diol (A1) is preferable, polyether diol obtained by adding AO to low molecular diol is more preferable, and polytetramethylene glycol is particularly preferable.

The number average molecular weight (Mn) of the diol (A) is 1,000 to 5,000, preferably 1,500 to 4,000, preferably 2,000 to 3,500, from the viewpoint of elongation and strength of the elastomer. Is more preferable.
When the number average molecular weight is less than 1,000, flexibility and elongation of the produced blade may be inferior, and when it exceeds 5,000, the hardness of the blade may be lowered.
The number average molecular weight can be measured, for example, by gel permeation chromatography (GPC).

-Diisocyanate (B)-
Examples of the diisocyanate (B) include (1) an aliphatic diisocyanate having 2 to 18 carbon atoms (excluding carbon in the NCO group, the same shall apply hereinafter), (2) an alicyclic diisocyanate having 4 to 15 carbon atoms, 3) aromatic diisocyanates having 6 to 14 carbon atoms, (4) araliphatic diisocyanates having 8 to 15 carbon atoms, and (5) modified products of these diisocyanates. These may be used individually by 1 type and may use 2 or more types together.

The (1) C2-C18 aliphatic diisocyanate is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include ethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate (HDI), and dodecamethylene diisocyanate. 2,2,4-trimethylhexamethylene diisocyanate, lysine diisocyanate, 2,6-diisocyanatomethylcaproate, bis (2-isocyanatoethyl) fumarate, bis (2-isocyanatoethyl) carbonate, 2-isocyanato And ethyl-2,6-diisocyanatohexanoate.
The (2) C 4-15 alicyclic diisocyanate is not particularly limited and may be appropriately selected depending on the intended purpose. For example, isophorone diisocyanate (IPDI), dicyclohexylmethane-4,4′-diisocyanate ( Hydrogenated MDI), cyclohexylene diisocyanate, methylcyclohexylene diisocyanate (hydrogenated TDI), bis (2-isocyanatoethyl) -4-cyclohexene, and the like.
Examples of the (3) C6-C14 aromatic diisocyanate include (i) at least one of 1,3-phenylene diisocyanate and 1,4-phenylene diisocyanate, and (ii) 2,4-tolylene diisocyanate (TDI). ) And 2,6-tolylene diisocyanate (TDI), (iii) crude TDI, at least one of 2,4′-diphenylmethane diisocyanate (MDI) and 4,4′-diphenylmethane diisocyanate (MDI), iv) 4,4'-diisocyanatobiphenyl, 3,3'-dimethyl-4,4'-diisocyanatobiphenyl, 3,3'-dimethyl-4,4'-diisocyanatodiphenylmethane, crude MDI, , 5-naphthylene diisocyanate, and the like.
Examples of the araliphatic diisocyanate having 8 to 15 carbon atoms include (i) at least one of m-xylylene diisocyanate (XDI) and p-xylylene diisocyanate (XDI), (ii) α, α, α ′, α′-tetramethylxylylene diisocyanate (TMXDI), and the like.
Examples of (5) modified products of these diisocyanates include modified diisocyanates having a carbodiimide group, a uretdione group, a uretoimine group, a urea group, and the like.
Among these, (2) alicyclic diisocyanate, (3) aromatic diisocyanate, and (4) araliphatic diisocyanate are preferable, and IPDI, hydrogenated MDI, MDI, XDI, and TMXDI are particularly preferable.

-Polysiloxane (C)-having two or more hydrolyzable alkoxy groups
Examples of the polysiloxane (C) having two or more hydrolyzable alkoxy groups include polysiloxane having two or more hydrolyzable alkoxy groups represented by the following general formula (i) in one molecule. Can be mentioned.

In the general formula (i), R represents an alkyl group having 1 to 4 carbon atoms, and examples thereof include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, and a sec-butyl group. Among these, a methyl group and an ethyl group are particularly preferable.
The hydrolyzable alkoxy group represented by the general formula (i) may be present in any part of the polysiloxane, for example, may be present only at the molecular end or in the repeating unit in the molecule.

  The polysiloxane (C) having two or more hydrolyzable alkoxy groups can be obtained by (I) condensation of a low-molecular silane compound or (II) introduction of an alkoxy group into the polysiloxane.

Preferred examples of the product obtained by condensation of the low molecular silane compound (I) include one or more condensates of a silane compound having a hydrolyzable alkoxy group represented by the following general formula (1).
R ¹ _m Si (OR ² ) _4-m ... General formula (1)
In the general formula (1), R ¹ represents an aliphatic saturated hydrocarbon group or an aromatic hydrocarbon group having 1 to 12 carbon atoms. R ² represents an alkyl group having 1 to 4 carbon atoms. m is an integer of 0-2.
Of R ¹ in the general formula (1), examples of the aliphatic saturated hydrocarbon group include a linear alkyl group, a branched alkyl group, and an alicyclic saturated hydrocarbon group.
Examples of the linear alkyl group include a methyl group, an ethyl group, an n-propyl group, an n-butyl group, an n-octyl group, an n-dodecyl group, or a deuterium substitution product thereof.
Examples of the branched alkyl group include isopropyl group, isobutyl group, sec-butyl group, 2-ethylhexyl group, and the like.
Examples of the cyclic saturated hydrocarbon group include a cyclohexyl group, a cyclooctyl group, a cyclohexylmethyl group, a cyclohexylethyl group, and a methylcyclohexyl group.
Of R ¹ in the general formula (1), examples of the aromatic hydrocarbon group include an aryl group, an aralkyl group, and an alkylaryl group.
Examples of the aryl group include a phenyl group, a biphenyl group, a naphthyl group, or their respective deuterium, fluorine or chlorine substituents.
Examples of the aralkyl group include a tolyl group, a xylyl group, a mesityl group, or their deuterium, fluorine, or chloride.
Examples of the alkylaryl group include methylphenyl and ethylphenyl groups.
Among these R ¹ , a linear alkyl group, a branched alkyl group, and an aryl group are preferable, a linear alkyl group and an aryl group are more preferable, and a methyl group, an ethyl group, a phenyl group, and a combination thereof are particularly preferable.
Among the condensates, particularly preferred is a condensate of a silane compound in which R ¹ in the general formula (1) is a phenyl group, or R ¹ is a phenyl group, from the viewpoint of compatibility with other components. It is a condensate of two or more silane compounds including a silane compound and a silane compound in which R ¹ is a linear alkyl group.

Examples of R ² in the general formula (1) include the same alkyl groups as those in R in the general formula (i), and preferred examples are also the same.
In the said General formula (1), m is an integer of 0-2.
Examples of the tetrafunctional silane compound in which m is 0, that is, four alkoxy groups include tetramethoxysilane, tetraethoxysilane, and the like.
Examples of the trifunctional silane compound in which m is 1, that is, three alkoxy groups include phenyltrimethoxysilane, phenyltriethoxysilane, methyltrimethoxysilane, methyltriethoxysilane, and the like.
Examples of the bifunctional silane compound in which m is 2, that is, two alkoxy groups include diphenyldimethoxysilane, diphenyldiethoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, phenylmethyldimethoxysilane, and phenylmethyldiethoxysilane. Can be mentioned.
Among these, m is 1, that is, a trifunctional silane compound is particularly preferable from the viewpoint of forming a uniform network of organopolysiloxane.

As the method for producing the condensate of the silane compound (I), for example, in a dry atmosphere, a predetermined amount of water and, if necessary, a catalyst is stirred for 10 to 60 minutes while stirring the catalyst. Then, it is obtained by aging at a temperature below the boiling point of the by-produced alcohol (for example, 0 ° C. to 150 ° C.) over 1 hour to 12 hours.
If the amount of water added in the reaction is X mole and the number of moles of alkoxy groups in the silane compound is Y, the yield and molecular weight of the condensate may be reduced if X / Y is too small. On the other hand, if X / Y is too large, the molecular weight becomes too large and the storage stability tends to decrease. Therefore, a range of 0.1 <X / Y <5 is preferable, and a range of 0.3 <X / Y <3 is more preferable. In addition, as water to add, ion-exchange water or distilled water is suitable.
If necessary, a silane compound having one hydrolyzable alkoxy group can be added for the purpose of adjusting the molecular weight. Examples of the silane compound having one hydrolyzable alkoxy group include phenyltrimethoxysilane and methyltrimethoxysilane.

The catalyst is not particularly limited and may be appropriately selected depending on the purpose. For example, formic acid, acetic acid, succinic acid, lactic acid, malonic acid, citric acid, tartaric acid, malic acid, succinic acid, fumaric acid, phthalic acid, Monovalent, divalent or trivalent organic acids such as pyromellitic acid, p-toluenesulfonic acid, methanesulfonic acid, trifluoroacetic acid, trifluoromethanesulfonic acid; hydrochloric acid, phosphoric acid, nitric acid, hydrofluoric acid, bromic acid, chlorine Inorganic acids such as acids and perchloric acids; alkali metal hydroxides, alkaline earth hydroxides, quaternary alkyl ammonium hydroxides, carbonates, alkali salts such as primary to tertiary amines; Secondary alkylammonium halides; sodium hypochlorite; alkoxides of metals other than silicon such as tin, zirconium, titanium, aluminum, boron, or their key Over preparative complex; and the like. Among these, acidic catalysts such as organic acids, inorganic acids, metal alkoxides, and metal alkoxide chelate compounds are preferable, and organic acids are particularly preferable.
The amount of the catalyst added is preferably 0.0001 to 10 parts by mass, and more preferably 0.001 to 1 part by mass with respect to 100 parts by mass of the silane compound.
There is no restriction | limiting in particular as the addition method of the said catalyst, Although it can select suitably according to the objective, It is preferable to add as aqueous solution.
The reaction temperature is preferably 20 ° C to 100 ° C.

The compound obtained by introducing an alkoxy group into the polysiloxane (II) can react with the reactive functional group with a silane compound having a hydrolyzable alkoxy group and another reactive functional group in one molecule. Examples thereof include a reaction product with polysiloxane having two or more functional groups in one molecule.
Examples of other reactive functional groups in the silane compound include a hydroxyl group, an amino group, a carboxyl group, a mercapto group, and a glycidyl group.
Examples of the silane compound include γ-glycidoxypropyltrimethoxysilane, 2-mercaptoethyltrimethoxysilane, and the like.
Examples of the functional group in the polysiloxane include a carboxyl group, an amino group, a hydroxyl group, and a mercapto group.
When the other reactive functional group in the silane compound is a glycidyl group, the functional group in the polysiloxane is preferably a carboxyl group or an amino group, and the other reactive functional group in the silane compound is a mercapto. In the case of a group, the functional group in the polysiloxane is preferably a glycidyl group or a carboxyl group.
Examples of the polysiloxane include polysiloxanes having carboxyl groups at both ends, polysiloxanes having amino groups at both ends, and polysiloxanes having glycidyl groups at both ends.

The reaction product (II) can be obtained, for example, by reacting γ-glycidoxypropyltrimethoxysilane with polysiloxane having carboxyl groups at both ends.
There is no restriction | limiting in particular in the said reaction temperature, According to the objective, it can select suitably, 70 to 110 degreeC is preferable.
The reaction time is not particularly limited and may be appropriately selected depending on the purpose. It is preferably 5 hours to 30 hours.
Further, if necessary, a catalyst (for example, triphenylphosphine) can be used.

The number average molecular weight (Mn) of the polysiloxane (C) having two or more hydrolyzable alkoxy groups is preferably 500 to 6,000 from the viewpoint of mechanical properties and heat resistance when it becomes a polyurethane elastomer, 1,000-5,000 are more preferable, and 2,000-4,000 are still more preferable. When the number average molecular weight (Mn) is less than 500, the flexibility and elongation of the produced blade may be inferior, and when it exceeds 6,000, the blade hardness may be lowered.
The number average molecular weight can be measured, for example, by gel permeation chromatography (GPC).
The content of the polysiloxane (C) is preferably 5% by mass to 30% by mass, more preferably 6% by mass to 20% by mass, and more preferably 8% by mass to 15% by mass with respect to the solid mass of the polyurethane elastomer. Further preferred. If the content is 5% by mass or more, the elongation can be exhibited better, and if the content is 30% by mass or less, the strength can be further improved.

-Acid generator (D)-
The acid generator (D) is a compound that generates an acid by light or heat, and is added to accelerate the condensation reaction.
The acid generator (D) is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include (i) a sulfone compound, (ii) a sulfonic acid ester compound, (iii) a sulfonimide compound, (iv) ) Disulfonyldiazomethane compounds, (v) disulfonylmethane compounds, (vi) onium salts, and the like. These may be used individually by 1 type and may use 2 or more types together.

Examples of the (i) sulfone compound include phenacylphenylsulfone, 4-trisphenacylsulfone-ketosulfone, β-sulfonylsulfone, and α-diazo compounds thereof.
Examples of the (ii) sulfonic acid ester compound include benzoin tosylate, pyrogallol tris trifluoromethanesulfonate, pyrogallol methanesulfonic acid triester, α-methylol benzoin tosylate, α-methylol benzoindodecyl sulfonate, and the like.
Examples of the (iii) sulfonimide compound include N- (trifluoromethylsulfonyloxy) succinimide, N- (p-toluenesulfonyloxy) bicyclo [2.2.1] hept-5-ene-2,3-di. Carboximide, N- (perfluorooctanesulfonyloxy) naphthylimide, N- (benzenesulfonyloxy) bicyclo [2.2.1] hept-5-ene-2,3-dicarboximide, N- (benzenesulfonyloxy) ) Bicyclo [2.2.1] heptane-5,6-oxy-2,3-dicarboximide, N- (benzenesulfonyloxy) naphthylimide, and the like.
Examples of the (iv) disulfonyldiazomethane compound include bis (trifluoromethylsulfonyl) diazomethane, bis (phenylsulfonyl) diazomethane, bis (p-toluenesulfonyl) diazomethane, bis (2,4-dimethylbenzenesulfonyl) diazomethane, and bis. (1-methylethylsulfonyl) diazomethane, bis (1,4-dioxaspiro [4,5] decan-7-sulfonyl) diazomethane, and the like.
Examples of the (vi) onium salt include sulfonium salts [bis [4- (diphenylsulfonio) phenyl] sulfide bishexafluorophosphate, allylsulfonium hexafluorophosphate salts, etc.], iodonium salts (diphenyliodonium hexafluorophosphate, etc.), Phosphonium salts (such as ethyltriphenylphosphonium tetrafluoroborate), diazonium salts (such as phenyldiazonium hexafluorophosphate), ammonium salts (such as 1-benzyl-2-cyanopyridinium hexafluorophosphate), ferrocene [(2,4-cyclopentadiene -1-yl) [(1-methylethyl) benzene] -Fe (II) hexafluorophosphate salt], and the like.
Among these acid generators (D), sulfonimide compounds and disulfonyldiazomethane compounds are preferable, and N- (trifluoromethylsulfonyloxy) succinimide and bis (phenylsulfonyl) diazomethane are particularly preferable.

  The content of the acid generator is preferably 10% by mass or less, more preferably 0.01% by mass to 7% by mass, and still more preferably 0.05% by mass to 5% by mass with respect to the solid content mass of the polyurethane elastomer. . If the content is 0.01% by mass or more, the mechanical properties can be exhibited well, and if the content is 10% by mass or less, the heat resistance can be further improved.

<Method for producing polyurethane elastomer>
As a method for producing the polyurethane elastomer, there are a prepolymer method and a one-shot method.
The prepolymer method is a two-stage method in which diisocyanate and polyol are reacted in an excess of diisocyanate to produce an isocyanate (NCO) -terminated prepolymer, and an elastomer is used as a chain extender.
In the one-shot method, without producing an NCO-terminated prepolymer, diisocyanate, polyol and chain extender are mixed and stirred at once in a reactor, cast into a molding die, and then cured by reaction to cure the elastomer. How to get.
Compared to the one-shot method, the prepolymer method generally has high strength and durability of the molded article obtained, and the prepolymer method is preferred as the method for producing the polyurethane elastomer of the present invention.

  In the prepolymer method, an NCO-terminated polyurethane prepolymer obtained by reacting a diol (A) having a number average molecular weight of 1,000 to 5,000 with a diisocyanate (B) is preferably chained with a chain extender (E). After the elongation reaction, a polyurethane elastomer can be obtained by adding and reacting a polysiloxane (C) having two or more hydrolyzable alkoxy groups and an acid generator (D).

-Chain extender (E)-
As the chain extender (E), the number average molecular weight is preferably 50 to 300, and from the viewpoint of mechanical strength, more preferably 50 to 150 diol (E1), the number average molecular weight is preferably 50 to 300, and the mechanical strength. More preferably, 50-150 diamine (E2) etc. are mentioned from a viewpoint. Among these, diol (E1) is particularly preferable. These may be used individually by 1 type and may use 2 or more types together.

The diol (E1) is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include aliphatic diols [ethylene glycol, diethylene glycol, 1,3-propanediol, 1,4-butanediol, , 5-pentanediol, 1,6-hexanediol, propylene glycol, neopentyl glycol, 3-methyl 1,5-pentanediol, 2,2-diethyl-1,3-propanediol, 1,2-, 1, 3-butanediol, 2,3-butanediol, etc.]; alicyclic diols [1,4-bis (hydroxymethyl) cyclohexane, m-xylylene glycol, p-xylylene glycol; bisphenol A ethylene oxide , Sometimes abbreviated as EO), propylene oxide (hereinafter abbreviated as PO) It is) adducts (molecular weight 50 to 300), etc.], or a mixture of two or more thereof.
Among these, ethylene glycol, 1,4-butanediol, 1,6-hexanediol, neopentyl glycol, EO addition product or PO addition product of bisphenol A are particularly preferable.

Examples of the diamine (E2) include aromatic diamines, aliphatic diamines, alicyclic diamines, or mixtures of two or more thereof.
Examples of the aromatic diamine include 4,4′-diaminodiphenylmethane, 4,4′-diaminodiphenyl ether, 4,4′-bis (4-aminophenoxy) biphenyl, and 4,4′-bis (3-aminophenoxy). Biphenyl, 1,4′-bis (4-aminophenoxy) benzene, 1,3′-bis (4-aminophenoxy) benzene, 1,3-bis (3-aminophenoxy) benzene, o-phenylenediamine, m- Phenylenediamine, p-phenylenediamine, 3,4'-diaminodiphenyl ether, 4,4'-diaminodiphenyl sulfone, 3,4-diaminodiphenyl sulfone, 3,3'-diaminodiphenyl sulfone, 4,4'-methylene-bis (2-chloroaniline), 3,3′-dimethyl-4,4′-diaminobiphenyl, 4,4 ′ -Diaminodiphenyl sulfide, 2,6'-diaminotoluene, 2,4-diaminochlorobenzene, 1,2-diaminoanthraquinone, 1,4-diaminoanthraquinone, 3,3'-diaminobenzophenone, 3,4-diaminobenzophenone, 4 , 4'-diaminobenzophenone, 4,4'-diaminobibenzyl, R (+)-2,2'-diamino-1,1'-binaphthalene, S (+)-2,2'-diamino-1,1 1, n-bis (1, -bis (4-aminophenoxy) alkane, 1,4-bis (4-aminophenoxy) alkane, 1,5-bis (4-aminophenoxy) alkane, etc. 4-aminophenoxy) alkane (n is 3 to 10), 1,2-bis [2- (4-aminophenoxy) ethoxy] ethane, 9,9-bis (4- Minofeniru) fluorene, 4,4'-diamino benzanilide and the like.
Examples of the aliphatic diamine include 1,2-diaminomethane, 1,4-diaminobutane, tetramethylenediamine, 1,5-diaminopentane, 1,6-diaminohexane, 1,8-diaminooctane, 1,10 -Diaminododecane, 1,11-diaminoundecane, and the like.
Examples of the alicyclic diamine include 1,4-diaminocyclohexane, 1,2-diaminocyclohexane, bis (4-aminocyclohexyl) methane, and 4,4′-diaminodicyclohexylmethane.
Among these, aliphatic diamines are preferable, and 1,2-diaminomethane, 1,4-diaminobutane, and tetramethylenediamine are particularly preferable.

In the NCO-terminated prepolymer used in the present invention, the ratio of the NCO equivalent of the diisocyanate (B) to the hydroxyl (OH) equivalent of the diol (A) (NCO / OH) is preferably 1.2 to 5, preferably 1.5. It mixes so that it may become-3, and after adding a catalyst (F) if necessary, it heats and is obtained by complete | finishing reaction.
When the (NCO / OH) ratio is 1.2 or more, the viscosity of the prepolymer is low and the moldability is good. When the (NCO / OH) ratio is 5 or less, the obtained elastomer has good elasticity at low temperatures.
The temperature during the production of the NCO-terminated prepolymer is preferably 100 ° C to 200 ° C. When the temperature is 100 ° C. or higher, the polyisocyanate component melts and the production time is shortened. When the temperature is 200 ° C. or lower, urethane does not thermally decompose and is stable.
Furthermore, the NCO-terminated prepolymer thus obtained is preferably extended with a chain extender (E) to produce a polyurethane elastomer.
The blending amount of the chain extender (E) is such that the ratio (H / NCO) of the active hydrogen equivalent of the chain extender to the NCO equivalent (excluding the active hydrogen of carboxylic acid and sulfonic acid) is 0.7 to 1 is preferable and 0.8-1 is more preferable. When the (H / NCO) ratio is 0.7 or more, the mechanical properties are good, and when it is 1 or less, the obtained elastomer may not be less elastic at low temperatures.

  Examples of the catalyst (F) that can be used as needed for the synthesis of the prepolymer include amines and organometallic catalysts.

Examples of the amines include monoamines, diamines, triamines, cyclic amines, alcohol amines, ether amines, and the like.
Examples of the monoamines include triethylamine (TEA) and N, N-dimethylcyclohexylamine (DMEDA).
Examples of the diamines include N, N, N ′, N′-tetramethylethylenediamine (TMEDA), N, N, N ′, N′-tetramethylpropane 1,3-diamine (TMPDA), N, N, N ′, N′-tetramethylhexane-1,6-diamine (TMHMDA) and the like can be mentioned.
Examples of the triamines include N, N, N ′, N ″, N ″ -pentamethyldiethylenetriamine (PMDETA), N, N, N ′, N ″, N ″ -pentamethyldipropylene-triamine (PMDPTA), Examples include tetramethylguanidine (TMG).
Examples of the cyclic amines include triethylenediamine (TEDA), N, N′-dimethylpiperazine (DMP), N-methyl-N ′-(2-dimethylamino) -ethylpiperazine (TMNAEP), N-methylmorpholine ( NMMO), N- (N ′, N′-dimethylaminoethyl) -morpholine (DMAEMO), 1,2-dimethylimidazole (DMIZ) and the like.
Examples of the alcohol amines include dimethylaminoethanol (DMEA), dimethylaminoethoxyethanol (DMAEE), N, N, N′-trimethylaminoethyl-ethanolamine (TMAEEA), N-methyl-N ′-(2- Hydroxyethyl) -piperazine (MHEP), N- (2-hydroxyethyl) morpholine (HEMO) and the like.
Examples of the ether amines include bis (2-dimethylaminoethyl) ether (BDMEE) and ethylene glycol bis (3-dimethyl) -aminopropyl ether.

  Examples of the organometallic catalyst include stannous octoate, dibutyltin diacetate, dibutyltin dilaurate, dibutyltin marker peptide, dibutyltin thiocarboxylate, dibutyltin dimaleate, dioctyltin marker peptide, dioctyltin thiocarboxylate, phenylmercury. Examples include propionate and phenylmercury octenoate.

  The temperature during the production of the polyurethane elastomer is preferably 80 ° C to 200 ° C. When the temperature is 80 ° C. or higher, the polyurethane elastomer is melted and the production time is shortened. When the temperature is 200 ° C. or lower, urethane is hardly thermally decomposed.

The number average molecular weight (Mn) of the polyurethane elastomer is preferably 10,000 to 200,000, and more preferably 20,000 to 100,000. When the number average molecular weight (Mn) is 10,000 or more, the strength of the molded product is obtained, and when it is 200,000 or less, the resultant melt viscosity is low and the moldability is good.
Here, the number average molecular weight can be measured by gel permeation chromatography (GPC). For example, using HLC-8220 (manufactured by Tosoh Techno System Co., Ltd.), dimethylformamide as a solvent, polystyrene resin Can be measured as a molecular weight calibration reagent.

The polyurethane elastomer is thermoplastic. For example, the melt flow rate (measurement conditions: temperature 230 ° C., load 2.16 kg) is preferably 0.1 g / 10 min to 10 g / 10 min, preferably 0.5 g / 10 min to 5 g / 10 min is more preferable.
30-100 are preferable and, as for the hardness (by the measurement of Shore A hardness according to JISK6301) of the said polyurethane elastomer, 50-80 are more preferable.
The softening temperature of the polyurethane elastomer (measured according to JIS K7206) is preferably 145 ° C to 220 ° C, more preferably 165 ° C to 195 ° C.

In addition to the polyurethane elastomer, a plasticizer, a pigment, and other additives can be added to the cleaning blade as necessary. These additives may be added to the polyol or may be added in advance to the NCO-terminated prepolymer.
Examples of the plasticizer include phthalic acid dialkyl esters.
Examples of the pigment include titanium dioxide.
Examples of the other additives include an antioxidant and a filler.
As the filler, in order to impart a minimal amount of wear, a filler having a very small average particle size of primary particles can be added. The size of the filler is preferably smaller than the particle size of the toner, and more preferably 1 μm or less.
The amount of the filler added is preferably 5% by mass or more from the viewpoint of viscoelastic mechanical properties of the cleaning blade, imparting a very small amount of wear, and extending the durability life.
Examples of the filler include one component of organic resin fine powder (for example, resin such as ultra-high density polyethylene, nylon, and fluorine resin) and inorganic fine powder (for example, molybdenum disulfide, fluorocarbon, silica, and the like). Alternatively, a multicomponent system may be used. Among these, fine powder silica (for example, wet silica and dry silica) is preferable from the viewpoints of particle size and dispersibility, and scratches on the surface of the electrostatic latent image carrier. Hydrophobic treated silica with improved dispersibility In view of the particle size, dry silica and hydrophobic dry-treated silica are more preferable.

  When the fluctuation range of the pressure contact force of the cleaning blade with respect to the electrostatic latent image carrier decreases below the predetermined minimum pressure contact force, the remaining toner may not be cleaned. For this reason, it is necessary to maintain the pressure contact force. However, since the polyurethane elastomer has irreversible deformation caused by the plastic flow inside the polyurethane elastomer with respect to the pressure contact force, that is, creep, a cleaning blade having a small creep is preferable. The compression set is preferably 20% or less, more preferably 10% or less.

In order to improve the cleaning performance by accurately applying the cleaning blade to an electrostatic latent image carrier, for example, a cylindrical photosensitive drum having a curvature, it is necessary to improve the dimensional accuracy of the cleaning blade itself. For this reason, as a method for manufacturing a cleaning blade, a method in which a molding die having a high dimensional accuracy is clamped at a high pressure and molded by an injection molding machine has the best dimensional accuracy, and has a high shear rate at the time of injection. Rubber flow is obtained, and the injection reaction time can be shortened, which is advantageous in production.
In addition, since there is a problem that it is difficult to obtain a strong adhesive force between the support member and the molded cleaning blade, a support member that is pre-coated with an adhesive is inserted into the mold at the part to be joined with the polyurethane elastomer composition at the time of injection molding. In addition, it is preferable that the polyurethane elastomer can be firmly bonded by using a rubberization reaction at the time of molding by integrally molding with the polyurethane elastomer. As a result, a cleaning blade with a short molding time and excellent quality can be manufactured.

(Image forming method and image forming apparatus)
The image forming apparatus of the present invention comprises at least an electrostatic latent image carrier, an electrostatic latent image forming unit, a developing unit, a transfer unit, a fixing unit, and a cleaning unit, and further if necessary. And other means appropriately selected, for example, static elimination means, recycling means, control means, and the like.
The image forming method of the present invention includes at least an electrostatic latent image forming step, a developing step, a transfer step, a fixing step, and a cleaning step, and further other steps appropriately selected as necessary, for example, static elimination. Process, recycling process, control process, etc.
The image forming method of the present invention can be preferably carried out by the image forming apparatus of the present invention, the electrostatic latent image forming step can be performed by the electrostatic latent image forming means, and the developing step is the developing The transfer step can be performed by the transfer unit, the fixing step can be performed by the fixing unit, the cleaning step can be performed by the cleaning unit, and the other steps. Can be performed by the other means.

-Electrostatic latent image forming step and electrostatic latent image forming means-
The electrostatic latent image forming step is a step of forming an electrostatic latent image on the electrostatic latent image carrier.
<Electrostatic latent image carrier>
The electrostatic latent image carrier is not particularly limited in its layer structure and can be appropriately selected according to the purpose. In the first embodiment, the photosensitive layer has a single layer structure on the support. (Hereinafter also referred to as “single-layer type photosensitive layer”), and further includes other layers such as a protective layer and an undercoat layer as necessary. In the second embodiment, there is provided a support, and a photosensitive layer having a structure in which a charge generation layer and a charge transport layer are stacked on the support (hereinafter sometimes referred to as “laminated photosensitive layer”). Furthermore, it has other layers, such as a protective layer and an undercoat layer, if necessary. In the second embodiment, the charge generation layer and the charge transport layer may be laminated in reverse.

Here, the electrostatic latent image carrier will be described by taking a function separation type stacked type as an example.
In FIG. 1, a photosensitive layer 202 including a charge generation layer 203 containing a charge generation material and a charge transport layer 204 containing a charge transport material is laminated on a support 201, and a protective layer is further formed on the surface of the charge transport layer. 205.
In FIG. 2, a photosensitive layer 202 composed of a charge transport layer 204 containing a charge transport material and a charge generation layer 203 containing a charge generation material is laminated on a support 201, and a protective layer is further formed on the surface of the charge generation layer. 205.

-Support-
The support is not particularly limited as long as it has a conductivity of 10 ¹⁰ Ω · cm or less, and can be appropriately selected according to the purpose. For example, aluminum, nickel, chromium, nichrome, copper, Metals such as gold, silver, platinum, etc .; metal oxides such as tin oxide, indium oxide, etc. deposited or sputtered on film or cylindrical plastic, paper coated, or aluminum, aluminum alloy, nickel, stainless steel, etc. It is possible to use a plate or a tube subjected to surface treatment such as cutting, super-finishing or polishing after forming a raw tube by a method such as extruding and drawing them. Further, an endless nickel belt and an endless stainless steel belt disclosed in JP-A-52-36016 can also be used as a support. Further, a nickel foil having a thickness of 50 μm to 150 μm may be used, or a surface of a polyethylene terephthalate film having a thickness of 50 μm to 150 μm may be subjected to conductive processing such as aluminum deposition.

In addition, those in which conductive powder is dispersed and coated on an appropriate binder resin on the support can also be used as the support. Examples of the conductive powder include carbon black, acetylene black, metal powder such as aluminum, nickel, iron, nichrome, copper, zinc, silver, or metal oxide powder such as conductive tin oxide and ITO. Etc. Examples of the binder resin used simultaneously include polystyrene resin, styrene-acrylonitrile copolymer, styrene-butadiene copolymer, styrene-maleic anhydride copolymer, polyester resin, polyvinyl chloride resin, vinyl chloride-acetic acid. Vinyl copolymer, polyvinyl acetate resin, polyvinylidene chloride resin, polyarylate resin, phenoxy resin, polycarbonate resin, cellulose acetate resin, ethyl cellulose resin, polyvinyl butyral resin, polyvinyl formal resin, polyvinyl toluene resin, poly-N-vinyl carbazole , Acrylic resin, silicone resin, epoxy resin, melamine resin, urethane resin, phenol resin, alkyd resin, and the like.
The conductive layer can be provided by dispersing and applying these conductive powder and binder resin in a solvent such as tetrahydrofuran, dichloromethane, methyl ethyl ketone, or toluene.
Furthermore, it is conductive by a heat shrinkable tube containing conductive powder in a material such as polyvinyl chloride, polypropylene, polyester, polystyrene, polyvinylidene chloride, polyethylene, chlorinated rubber, Teflon (registered trademark) on a cylindrical substrate. Those provided with a layer can also be used favorably as a conductive support.

[Laminated photosensitive layer]
The laminated photosensitive layer has a charge generation layer and a charge transport layer at least in this order.
-Charge generation layer-
The charge generation layer contains at least a charge generation material, and contains a binder resin and, if necessary, other components.
As the charge generation material, an inorganic material or an organic material is used, and typical examples include a monoazo pigment, a disazo pigment, a trisazo pigment, a perylene pigment, a perinone pigment, a quinacridone pigment, and a quinone condensed polycyclic compound. Squalic acid dyes, phthalocyanine pigments, naphthalocyanine pigments, azulenium salt dyes, selenium, selenium-tellurium alloys, selenium-arsenic alloys, amorphous silicon, and the like. These may be used alone or in combination of two or more.

Examples of the binder resin include polyamide resin, polyurethane resin, polyester resin, epoxy resin, polyketone resin, polycarbonate resin, silicone resin, acrylic resin, polyvinyl butyral resin, polyvinyl formal resin, polyvinyl ketone resin, polystyrene resin, polyacrylic resin, And polyamide resin.
The content of the binder resin is preferably 0 to 2 parts by mass with respect to 1 part by mass of the charge generation material.
In the charge generation layer, the charge generation material is dispersed by a ball mill, an attritor, a sand mill or the like using a solvent such as tetrahydrofuran, cyclohexanone, dioxane, 2-butanone or dichloroethane together with a binder resin, and a dispersion is applied. Can be formed. Examples of the application include a dip coating method, a spray coating method, and a bead coating method.
The thickness of the charge generation layer is preferably 0.01 μm to 5 μm, and more preferably 0.1 μm to 2 μm.

-Charge transport layer-
The charge transport layer contains at least a charge transport material and a binder resin, and is formed by further dissolving or dispersing a plasticizer, a leveling agent, etc. in an appropriate solvent, if necessary, and applying and drying. be able to.
Among the charge transport materials, low molecular charge transport materials include electron transport materials and hole transport materials. Examples of the electron transporting material include chloroanil, bromoanil, tetracyanoethylene, tetracyanoquinodimethane, 2,4,7-trinitro-9-fluorenone, 2,4,5,7-tetranitro-9-fluorenone, 2 , 4,5,7-tetranitroxanthone, 2,4,8-trinitrothioxanthone, 2,6,8-trinitro-4H-indeno [1,2-b] thiophene-4-one, 1,3,7- And trinitrodibenzothiophene-5,5-dioxide. These may be used individually by 1 type and may use 2 or more types together.
Examples of the hole transport material include oxazole derivatives, oxadiazole derivatives, imidazole derivatives, triphenylamine derivatives, 9- (p-diethylaminostyrylanthracene), 1,1-bis- (4-dibenzylaminophenyl). Examples include propane, styrylanthracene, styrylpyrazoline, phenylhydrazones, α-phenylstilbene derivatives, thiazole derivatives, triazole derivatives, phenazine derivatives, acridine derivatives, benzofuran derivatives, benzimidazole derivatives, and thiophene derivatives. These may be used individually by 1 type and may use 2 or more types together.
In addition, a polymer charge transport material can be used as the charge transport material. The polymer charge transporting material is preferably a material having a charge transporting substituent in the main chain or side chain in a low molecular charge transporting material. Examples of the polymer charge transport material include polycarbonate, polyurethane, polyester, polyether, and the like. Among these, a polycarbonate having a triarylamine structure is particularly preferable.
The content of the charge transport material is preferably 40% by mass or more of the charge transport layer. When the content is less than 40% by mass, sufficient light decay time in a high-speed electrophotographic process may not be obtained in pulsed light exposure in laser writing on a photoreceptor.

An appropriate amount of a binder resin, a plasticizer, a leveling agent, a lubricant and the like can be added to the charge transport layer as necessary.
There is no restriction | limiting in particular as said binder resin, According to the objective, it can select suitably, For example, a polystyrene resin, a styrene-acrylonitrile copolymer, a styrene-butadiene copolymer, a styrene-maleic anhydride copolymer, polyester Resin, polyvinyl chloride resin, vinyl chloride-vinyl acetate copolymer, polyvinyl acetate resin, polyvinylidene chloride resin, polyarylate resin, phenoxy resin, polycarbonate resin, cellulose acetate resin, ethyl cellulose resin, polyvinyl butyral resin, polyvinyl formal resin , Polyvinyl toluene resin, acrylic resin, silicone resin, epoxy resin, melamine resin, urethane resin, phenol resin, alkyd resin, and the like.
Examples of the plasticizer include general-purpose plasticizers such as dibutyl phthalate and dioctyl phthalate, and the amount used is preferably 0% by mass to 30% by mass with respect to the binder resin.
Examples of the leveling agent include silicone oils such as dimethyl silicone oil and methylphenyl silicone oil, and polymers or oligomers having a perfluoroalkyl group in the side chain. The amount used is 0% by mass with respect to the binder resin. -1 mass% is preferable.
The charge transport layer can be formed by dissolving or dispersing these charge transport materials and a binder resin in an appropriate solvent, applying the solution, and drying.
In addition to the charge transport material and the binder resin, an appropriate amount of additives such as a plasticizer, an antioxidant, and a leveling agent can be added to the charge transport layer as necessary. Examples of the solvent include tetrahydrofuran, dioxane, toluene, 2-butanone, monochlorobenzene, dichloroethane, methylene chloride, and the like.
The thickness of the charge transport layer is preferably 5 μm to 30 μm, and can be appropriately selected according to desired photoreceptor characteristics.

(Single layer type photosensitive layer)
The single-layer type photosensitive layer includes a charge generation material, a charge transport material, a binder resin, and other components as necessary. As the charge generation material, the charge transport material, and the binder resin, the above-described materials can be used. Examples of other components include plasticizers, fine particles, and various additives.
The amount of the charge generating material added is preferably 5 to 40 parts by mass with respect to 100 parts by mass of the binder resin.
The addition amount of the charge transport material is preferably 0 to 190 parts by mass, more preferably 50 to 150 parts by mass with respect to 100 parts by mass of the binder resin.
The thickness of the single-layer type photosensitive layer is not particularly limited and can be appropriately selected according to the purpose, and is preferably 5 μm to 25 μm.

-Undercoat layer-
An undercoat layer may be provided between the support and the photosensitive layer as necessary. The undercoat layer is provided for the purpose of improving adhesiveness, preventing moire, improving the coatability of the upper layer, and reducing residual potential.
The undercoat layer contains at least a resin and fine powder, and further contains other components as necessary.
The resin is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include water-soluble resins such as polyvinyl alcohol resin, casein and sodium polyacrylate; alcohols such as copolymer nylon and methoxymethylated nylon. Soluble resins; curable resins that form a three-dimensional network structure such as polyurethane resins, melamine resins, alkyd-melamine resins, and epoxy resins.
Examples of the fine powder include metal oxides such as titanium oxide, silica, alumina, zirconium oxide, tin oxide, and indium oxide, metal sulfides, and metal nitrides.
Moreover, what contains a silane coupling agent, a titanium coupling agent, a chromium coupling agent etc. as an undercoat layer can also be used. Further, as an undercoat layer, an anodized layer of Al ₂ O ₃ , an organic material such as polyparaxylylene (parylene), or an inorganic material such as SiO ₂ , SnO ₂ , TiO ₂ , ITO, or CeO ₂ is vacuum thin film. Those provided by the manufacturing method can also be used.
There is no restriction | limiting in particular about the thickness of the said undercoat layer, According to the objective, it can select suitably, 0.1 micrometer-10 micrometers are preferable, and 1 micrometer-5 micrometers are more preferable.

-Protective layer-
The electrostatic latent image carrier preferably has a protective layer as an outermost layer for the purpose of protecting the photosensitive layer and improving durability.
The protective layer contains a binder resin and a filler, and further contains other components as necessary.
There is no restriction | limiting in particular as said binder resin, According to the objective, it can select suitably, For example, an olefin-vinyl monomer copolymer, chlorinated polyether resin, allyl resin, phenol resin, polyacetal resin, polyamide resin, polyamide Imide resin, polyacrylate resin, polyallylsulfone resin, polybutylene resin, polybutylene terephthalate resin, polycarbonate resin, polyethersulfone resin, polyether resin, polyethylene terephthalate resin, polyimide resin, acrylic resin, polymethylpentene resin, polypropylene resin, polyphenylene Oxide resin, polysulfone resin, AS resin, ABS resin, ACS resin, polyurethane resin, polyvinyl chloride resin, polyvinylidene chloride resin, epoxy resin, etc. That.
A filler is added to the protective layer for the purpose of improving wear resistance. Examples of the filler include alumina particles, titanium oxide particles, and silica particles. Among these, alumina particles and titanium oxide particles are particularly preferable.
The addition amount of the filler in the protective layer is preferably 10% by mass to 40% by mass, and more preferably 20% by mass to 30% by mass. If the added amount of the filler is less than 10% by mass, the wear may be large and the durability may be inferior. It may not be negligible.

A dispersion aid can be added to the protective layer in order to improve the dispersibility of the filler. As the dispersion aid, those used in coatings and the like (for example, modified epoxy resin condensate, unsaturated polycarboxylic acid low molecular weight polymer, etc.) can be used as appropriate, and the amount is 0.000 relative to the amount of filler contained. 5 mass%-4 mass% are preferable, and 1 mass%-2 mass% are more preferable.
In addition, it is very effective to add the above-described charge transport material to the protective layer, and the addition amount may be the same, and the characteristics for exposure can be improved. Further, an antioxidant can be added as necessary. The antioxidant will be described later.
Further, as other forms of the protective layer, JP 2007-108651 A, JP 2007-042002 A, JP 2007-025161, JP 2006-227567 A, JP 2007-17672 A, Japanese Patent Application Publication No. 2007-017633, Japanese Patent Application Publication No. 2006-243342, Japanese Patent Application Publication No. 2005-227761, Japanese Patent Application Publication No. 2006-003863, Japanese Patent Application Publication No. 2006-138951, etc. Can also be used effectively.
These have dramatically improved wear resistance by polymerizing the crosslinkable resin and the crosslinkable charge transport material, and when used in combination with the cleaning blade of the present invention, higher durability is achieved. An improved image forming unit can be realized.
As a method for forming the protective layer, a normal coating method such as a dip coating method or a spray method is employed.
The thickness of the protective layer is preferably 0.5 μm to 10 μm, more preferably 4 μm to 6 μm.

-Intermediate layer-
It is also possible to form another intermediate layer between the photosensitive layer and the protective layer. The intermediate layer contains a binder resin, and further contains other components as necessary.
Examples of the binder resin include polyamide resin, alcohol-soluble nylon, water-soluble polyvinyl butyral resin, polyvinyl butyral resin, and polyvinyl alcohol resin.
As the method for forming the intermediate layer, the above-described normal coating method is adopted, and the thickness of the intermediate layer is preferably 0.05 μm to 2 μm.

  In the electrostatic latent image carrier, for the purpose of improving the environmental resistance, the charge generation layer, the charge transport layer, the subbing layer, the protective layer, and the single layer are used for the purpose of preventing a decrease in sensitivity and an increase in residual potential. An antioxidant, a plasticizer, a lubricant, an ultraviolet absorber, a low molecular charge transport material, a leveling agent, and the like can be added to each layer such as a type photosensitive layer.

  Examples of the antioxidant include phenolic compounds, paraphenylenediamines, organic sulfur compounds, and organic phosphorus compounds.

  The plasticizer is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include phosphate ester plasticizers, phthalate ester plasticizers, aromatic carboxylic ester plasticizers, and aliphatic dibasic acids. Ester plasticizers, fatty acid ester derivatives, oxyacid ester plasticizers, epoxy plasticizers, dihydric alcohol ester plasticizers, chlorine-containing plasticizers, polyester plasticizers, sulfonic acid derivatives, citric acid derivatives, other plasticizers Etc.

  The lubricant is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include hydrocarbon compounds, fatty acid compounds, fatty acid amide compounds, ester compounds, alcohol compounds, metal soaps, natural waxes, Other lubricants can be mentioned.

  The ultraviolet absorber is not particularly limited and may be appropriately selected depending on the intended purpose. For example, a benzophenone ultraviolet absorber, a salicylate ultraviolet absorber, a benzotriazole ultraviolet absorber, a cyanoacrylate ultraviolet absorber, Examples include quencher (metal complex salt) ultraviolet absorbers and HALS (hindered amine).

<Charging process and exposure process>
The formation of the electrostatic latent image can be performed by charging the surface of the electrostatic latent image carrier and then exposing it like an image, and can be performed by electrostatic latent image forming means. The electrostatic latent image forming unit includes, for example, at least a charger that charges the surface of the latent image carrier and an exposure device that exposes the surface of the electrostatic latent image carrier imagewise. Charging can be performed, for example, by applying a voltage to the surface of the electrostatic latent image carrier using a charger.
The charger is not particularly limited and may be appropriately selected depending on the purpose. For example, a known contact charging device including a conductive or semiconductive roller, brush, film, rubber blade, etc. And non-contact chargers using corona discharge such as corotrons and corotrons. The shape of the charging member may take any form such as a magnetic brush or a fur brush in addition to the roller, and can be selected according to the specifications and form of the image forming apparatus. In the case of using a magnetic brush, the magnetic brush is composed of various ferrite particles such as Zn—Cu ferrite as a charging member, a non-magnetic conductive sleeve for supporting it, and a magnet roll included therein. In addition, when using a brush, for example, as a material of the fur brush, a fur treated with carbon, copper sulfide, metal or metal oxide is used, and this is wound around a metal or other conductive core. Make it a charger by sticking. The charger is not limited to the contact charger as described above, but it is preferable to use a contact charger because an image forming apparatus with reduced ozone generated from the charger can be obtained. .

  The exposure can be performed, for example, by exposing the surface of the electrostatic latent image carrier imagewise using an exposure device. The exposure device is not particularly limited as long as it can expose the surface of the electrostatic latent image carrier charged by the charger as an image to be formed, and can be appropriately selected according to the purpose. Examples include various exposure devices such as a copying optical system, a rod lens array system, a laser optical system, and a liquid crystal shutter optical system. In the present invention, a back light system in which imagewise exposure is performed from the back side of the electrostatic latent image carrier may be employed.

<Development process and development means>
The developing step is a step of forming a visible image by developing the electrostatic latent image using a toner or a developer. The visible image can be formed, for example, by developing the electrostatic latent image using a toner or a developer, and can be performed by a developing unit.
The developing unit is not particularly limited as long as it can be developed using, for example, toner or developer, and can be appropriately selected from known ones. Preferable examples include those having at least a developing device capable of applying toner or developer to the latent image in a contact or non-contact manner. The developing unit may be of a dry development type, may be of a wet development type, may be a single color developer, or may be a multicolor developer. Suitable examples include those having a stirrer for charging toner and developer by frictional stirring and a rotatable magnet roller. In the developing device, for example, the toner and the carrier are mixed and stirred, and the toner is charged by friction at that time, and held on the surface of the rotating magnet roller in a raised state, thereby forming a magnetic brush. Since the magnet roller is disposed in the vicinity of the latent image carrier, a part of the toner constituting the magnetic brush formed on the surface of the magnet roller is applied to the surface of the electrostatic latent image carrier by an electric attractive force. Moving. As a result, the electrostatic latent image is developed with toner, and a visible image is formed with toner on the surface of the electrostatic latent image carrier. The developer accommodated in the developing device is a developer containing toner, but the developer may be a one-component developer or a two-component developer.

<Toner>
Next, the toner used in the developing process will be described in detail. The toner preferably has a volume average particle size of 5.5 μm or less, and more preferably 4.5 μm to 5.5 μm. When the volume average particle size exceeds 5.5 μm, it may be difficult to achieve high definition of the formed image.
Here, the volume average particle diameter of the toner is measured by, for example, a Coulter counter method.
The average circularity of the toner is preferably 0.97 or more, more preferably 0.97 to 0.98. The average circularity is an index of the degree of unevenness of the toner particles, and indicates 1.00 when the toner is a perfect sphere, and the average circularity becomes smaller as the surface shape becomes more complicated. When the average circularity is less than 0.97, the so-called polymerization method for producing a small particle size toner is essentially close to a sphere, but is formed by carrying out a deforming process in an additional step. Therefore, the deforming treatment is necessary because the cleaning property is insufficient. Therefore, the above range is preferable from the viewpoint of production cost.
Here, the average circularity can be measured using, for example, a flow-type particle image analyzer (manufactured by Toa Medical Electronics Co., Ltd., FPIA-1000).

The small particle size and spherical toner is not particularly limited as long as it satisfies the above average circularity and volume average particle size, and can be appropriately selected according to the purpose. In addition, a method in which monomers are emulsion polymerized in a liquid (in an aqueous medium) to prepare fine polymer particles (resin particles), and then an organic solvent and a flocculant are added to associate the resin particles. Can be manufactured.
Such a small particle size and spherical toner contains a binder resin, a pigment, a charge control agent, and a release agent, and further contains other components as necessary.

  The binder resin is not particularly limited and may be appropriately selected depending on the purpose. For example, polystyrene resin, epoxy resin, polyester resin, polyamide resin, styrene acrylic resin, styrene methacrylate resin, polyurethane resin, vinyl resin, Examples include polyolefin resins, styrene butadiene resins, phenol resins, polyethylene resins, silicone resins, butyral resins, terpene resins, polyol resins, and the like. Among these, vinyl resins and polyester resins are particularly preferable. These may be used individually by 1 type and may use 2 or more types together.

  Examples of the vinyl resin include homopolymers of styrene such as polystyrene, poly-p-chlorostyrene, and polyvinyltoluene, and substituted products thereof: styrene-p-chlorostyrene copolymer, styrene-propylene copolymer, styrene- Vinyl toluene copolymer, styrene-vinyl naphthalene copolymer, styrene-methyl acrylate copolymer, styrene-ethyl acrylate copolymer, styrene-butyl acrylate copolymer, styrene-octyl acrylate copolymer, Styrene-methyl methacrylate copolymer, styrene-ethyl methacrylate copolymer, styrene-butyl methacrylate copolymer, styrene-α-chloromethyl methacrylate copolymer, styrene-acrylonitrile copolymer, styrene-vinylmethyl Ether copolymer, styrene-vinyl Ethyl ether copolymer, styrene-vinyl methyl ketone copolymer, styrene-butadiene copolymer, styrene-isoprene copolymer, styrene-acrylonitrile-indene copolymer, styrene-maleic acid copolymer, styrene-maleic acid Styrenic copolymers such as ester copolymers: polymethyl methacrylate, polybutyl methacrylate, polyvinyl chloride, polyvinyl acetate, and the like.

The polyester resin is composed of a dihydric alcohol as shown in the following group A and a dibasic acid salt as shown in the group B, and more than trivalent as shown in the group C. Alcohol or carboxylic acid may be added as a third component.
Examples of Group A include ethylene glycol, triethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,4 butanediol, neopentyl glycol, 1,4 butenediol, 1,4-bis ( Hydroxymethyl) cyclohexane, bisphenol A, hydrogenated bisphenol A, polyoxyethylenated bisphenol A, polyoxypropylene (2,2) -2,2′-bis (4-hydroxyphenyl) propane, polyoxypropylene (3,3 ) -2,2-bis (4-hydroxyphenyl) propane, polyoxyethylene (2,0) -2,2-bis (4-hydroxyphenyl) propane, polyoxypropylene (2,0) -2,2 ′ -Bis (4-hydroxyphenyl) propane and the like.
Examples of the group B include maleic acid, fumaric acid, mesaconic acid, citraconic acid, itaconic acid, glutaconic acid, phthalic acid, isophthalic acid, terephthalic acid, cyclohexanedicarboxylic acid, succinic acid, adipic acid, sebacic acid, malonic acid, Linolenic acid, or acid anhydrides or esters of lower alcohols thereof can be used.
Examples of Group C include trivalent or higher alcohols such as glycerin, trimethylolpropane and pentaerythritol, and trivalent or higher carboxylic acids such as trimellitic acid and pyromellitic acid.

  Examples of the polyol resin include an alkylene oxide adduct of an epoxy resin and a dihydric phenol, or a compound having one active hydrogen that reacts with the glycidyl ether and an epoxy group in the molecule, and an active hydrogen that reacts with the epoxy resin in the molecule. And those obtained by reacting a compound having two or more thereof.

There is no restriction | limiting in particular as said pigment, According to the objective, it can select suitably, For example, a black pigment, a yellow pigment, an orange pigment, a red pigment, a purple pigment, a blue pigment, a green pigment etc. are mentioned. These may be used individually by 1 type and may use 2 or more types together.
Examples of the black pigment include azine dyes such as carbon black, oil furnace black, channel black, lamp black, acetylene black, and aniline black, metal salt azo dyes, metal oxides, and composite metal oxides.
Examples of the yellow pigment include cadmium yellow, mineral fast yellow, nickel titanium yellow, navel yellow, naphthol yellow S, Hansa Yellow G, Hansa Yellow 10G, Benzidine Yellow GR, Quinoline Yellow Lake, Permanent Yellow NCG, Tartrazine Lake. Etc.
Examples of the orange pigment include molybdenum orange, permanent orange GTR, pyrazolone orange, Vulcan orange, indanthrene brilliant orange RK, benzidine orange G, indanthrene brilliant orange GK and the like.
Examples of the red pigment include Bengala, Cadmium Red, Permanent Red 4R, Resol Red, Pyrazolone Red, Watching Red Calcium Salt, Lake Red D, Brilliant Carmine 6B, Eosin Lake, Rhodamine Lake B, Alizarin Lake, Brilliant Carmine 3B, and the like. Is mentioned.
Examples of the purple pigment include fast violet B and methyl violet lake.
Examples of the blue pigment include cobalt blue, alkali blue, Victoria blue lake, phthalocyanine blue, metal-free phthalocyanine blue, phthalocyanine blue partial chlorinated product, first sky blue, and indanthrene blue BC.
Examples of the green pigment include chrome green, chromium oxide, pigment green B, and malachite green lake.
Among these, as a color toner, it is essential to uniformly disperse a good pigment. Instead of putting the pigment directly into a large amount of resin, a master batch in which the pigment is once dispersed at a high concentration is prepared. A method of feeding in a diluted form is used.

The charge control agent may be blended (internally added) inside the toner particles or mixed (externally added) with the toner particles. The charge control agent makes it possible to control the optimum charge amount according to the development system, and in the present invention, the balance between the particle size distribution and the charge amount can be further stabilized.
For controlling the toner to be positively charged, for example, nigrosine, a quaternary ammonium salt, a triphenylmethane dye, an imidazole metal complex or a salt thereof can be used alone or in combination of two or more.
Examples of toners that control negative charge include salicylic acid metal complexes or salts thereof, organic boron salts, calixarene compounds, and the like.

Examples of the release agent include natural waxes such as candelilla wax, carnauba wax, and rice wax; montan wax or derivatives thereof, paraffin wax or derivatives thereof, polyolefin wax or derivatives thereof, sazol wax, low molecular weight polyethylene, Low molecular weight polypropylene, alkyl phosphate ester, etc. are mentioned.
The melting point of the release agent is preferably 65 ° C to 90 ° C. If the melting point is less than 65 ° C., blocking during storage of the toner tends to occur, and if it exceeds 90 ° C., offset tends to occur in a region where the fixing roller temperature is low.

  Additives may be added for the purpose of improving dispersibility of the release agent and the like. Examples of additives include styrene-acrylic resin, polyethylene resin, polystyrene resin, epoxy resin, polyester resin, polyamide resin, styrene methacrylate resin, polyurethane resin, vinyl resin, polyolefin resin, styrene butadiene resin, phenol resin, butyral resin, terpene. Examples thereof include resins and polyol resins. These may be used individually by 1 type and may use 2 or more types together.

The toner may be subjected to surface modification by embedding an external additive on the surface of the toner base particles. Fine unevenness can be formed on the toner surface by mixing organic resin particles or inorganic fine particles of 1/10 or less of the base particles, and fixing to the base surface by heat treatment or the like.
The external additive is not particularly limited and may be appropriately selected from known ones according to the purpose. For example, silica fine particles, hydrophobized silica fine particles, fatty acid metal salts (for example, zinc stearate, And aluminum oxide stearate); metal oxides (for example, titania, alumina, tin oxide, antimony oxide, etc.) or their hydrophobized products, fluoropolymers, and the like. Among these, hydrophobized silica fine particles, titania particles, and hydrophobized titania fine particles are particularly preferable.
Examples of the silica fine particles include HDK H 2000, HDK H 2000/4, HDK H 2050EP, HVK21, HDK H1303 (all manufactured by Hoechst); R972, R974, RX200, RY200, R202, R805, R812 (all , Manufactured by Nippon Aerosil Co., Ltd.).
Examples of the titania fine particles include P-25 (manufactured by Nippon Aerosil Co., Ltd.); STT-30, STT-65C-S (both manufactured by Titanium Industry Co., Ltd.); TAF-140 (manufactured by Fuji Titanium Industry Co., Ltd.); Examples include MT-150W, MT-500B, MT-600B, MT-150A (all manufactured by Teika Corporation).
Examples of the hydrophobized titanium oxide fine particles include T-805 (manufactured by Nippon Aerosil Co., Ltd.); STT-30A, STT-65S-S (both manufactured by Titanium Industry Co., Ltd.); TAF-500T, TAF-1500T. (Both manufactured by Fuji Titanium Industry Co., Ltd.); MT-100S, MT-100T (both manufactured by Teika Co., Ltd.); IT-S (produced by Ishihara Sangyo Co., Ltd.) and the like.
In order to obtain the hydrophobized silica fine particles, the hydrophobized titania fine particles, and the hydrophobized alumina fine particles, the hydrophilic fine particles are made of silane cups such as methyltrimethoxysilane, methyltriethoxysilane, and octyltrimethoxysilane. It can be obtained by treating with a ring agent.
Examples of the hydrophobizing agent include silane coupling agents such as dialkyldihalogenated silanes, trialkylhalogenated silanes, alkyltrihalogenated silanes, and hexaalkyldisilazanes; silylating agents and silane couplings having a fluorinated alkyl group. Agents, organic titanate coupling agents, aluminum coupling agents, silicone oils, silicone varnishes and the like.

Further, silicone oil-treated inorganic fine particles obtained by treating the inorganic fine particles with silicone oil if necessary are also suitable.
The inorganic fine particles are not particularly limited and may be appropriately selected depending on the purpose. For example, silica, alumina, titanium oxide, barium titanate, magnesium titanate, calcium titanate, strontium titanate, iron oxide, oxidation Copper, zinc oxide, tin oxide, silica sand, clay, mica, wollastonite, diatomaceous earth, chromium oxide, cerium oxide, pengala, antimony trioxide, magnesium oxide, zirconium oxide, parium sulfate, barium carbonate, calcium carbonate, carbonized Examples thereof include silicon and silicon nitride. Among these, silica and titanium dioxide are particularly preferable.
The silicone oil is not particularly limited and may be appropriately selected depending on the intended purpose. For example, dimethyl silicone oil, methylphenyl silicone oil, chlorophenyl silicone oil, methyl hydrogen silicone oil, alkyl-modified silicone oil, fluorine-modified Silicone oil, polyether modified silicone oil, alcohol modified silicone oil, amino modified silicone oil, epoxy modified silicone oil, epoxy / polyether modified silicone oil, phenol modified silicone oil, carboxyl modified silicone oil, mercapto modified silicone oil, acrylic modified silicone Examples thereof include oil, methacryl-modified silicone oil, and α-methylstyrene-modified silicone oil.

The average particle size of primary particles of the inorganic fine particles is preferably 1 nm to 100 nm, and more preferably 3 nm to 70 nm. When the average particle size is less than 1 nm, the inorganic fine particles are embedded in the toner, and the function may not be effectively exhibited. When the average particle size exceeds 100 nm, the surface of the electrostatic latent image carrier is damaged unevenly. May end up.
As the external additive, inorganic fine particles and hydrophobic treated inorganic fine particles can be used in combination. The average particle size of the hydrophobized primary particles is preferably 1 nm to 100 nm, and more preferably 5 nm to 70 nm. More preferably, the primary particles subjected to the hydrophobization treatment include at least two types of inorganic fine particles having an average particle diameter of 20 nm or less and at least one type of inorganic fine particles of 30 nm or more. Further, BET specific surface area of the inorganic fine particles ^is preferably 20m ² / g~500m 2 / g.
The addition amount of the external additive is preferably 0.01% by mass to 5% by mass and more preferably 0.03% by mass to 2% by mass with respect to the toner.

<Transfer process and transfer means>
The transfer step is a step of transferring the visible image onto a recording medium. After the primary transfer of the visible image onto the intermediate transfer member using an intermediate transfer member, the visible image is transferred onto the recording medium. A primary transfer step of forming a composite transfer image by transferring a visible image onto an intermediate transfer body using two or more colors, preferably full color toner as the toner, and a composite transfer image; A mode including a secondary transfer step of transferring the transfer image onto the recording medium is more preferable.
The transfer can be performed, for example, by charging the electrophotographic photosensitive member with the visible image using a transfer charger, and can be performed by the transfer unit. The transfer means includes a primary transfer means for transferring a visible image onto an intermediate transfer member to form a composite transfer image, and a secondary transfer means for transferring the composite transfer image onto a recording medium. Embodiments are preferred.
The intermediate transfer member is not particularly limited and may be appropriately selected from known transfer members according to the purpose. For example, a transfer belt and the like are preferable.

The transfer unit (the primary transfer unit and the secondary transfer unit) includes at least a transfer unit that peels and charges the visible image formed on the electrophotographic photosensitive member toward the recording medium. preferable. There may be one transfer means or two or more transfer means. Examples of the transfer device include a corona transfer device using corona discharge, a transfer belt, a transfer roller, a pressure transfer roller, and an adhesive transfer device.
The recording medium is typically plain paper, but is not particularly limited as long as it can transfer an unfixed image after development, and can be appropriately selected according to the purpose. Etc. can also be used.

<Fixing process and fixing means>
The fixing step is a step of fixing the visible image transferred to the recording medium using a fixing device, and may be performed each time the toner of each color is transferred to the recording medium, or may be performed on the toner of each color. You may carry out simultaneously in the state which laminated | stacked. The fixing unit is not particularly limited and may be appropriately selected depending on the intended purpose. A fixing unit and a heat source for heating the fixing member are used. Examples of the fixing member include a combination of an endless belt and a roller, and a combination of a roller and a roller. However, the warm-up time can be shortened, and in terms of realizing energy saving, the fixing is also performed. A combination of an endless belt and a roller having a small heat capacity is preferable in terms of expanding the possible width.

-Static elimination process and static elimination means-
The neutralization step is a step of performing neutralization by applying a neutralization bias to the electrostatic latent image carrier, and can be suitably performed by a neutralization unit. The neutralization means is not particularly limited as long as a neutralization bias can be applied to the electrostatic latent image carrier, and can be appropriately selected from known neutralizers. It is done.

-Cleaning process and cleaning means-
The cleaning step is a step of removing toner remaining on the electrostatic latent image carrier and foreign matters other than the toner, and can be performed by a cleaning unit. As the cleaning means, the cleaning blade of the present invention that can keep the cost low without complicating the mechanism is used.
A combination with a known cleaner such as a magnetic brush cleaner, electrostatic brush cleaner, magnetic roller cleaner, brush cleaner, web cleaner, etc. is also effective as a good cleaning process.

-Recycling process and recycling means-
The recycling process is a process in which the toner removed by the cleaning process is recycled to the developing unit, and can be suitably performed by the recycling unit. There is no restriction | limiting in particular as said recycling means, A well-known conveyance means etc. are mentioned.

-Control process and control means-
The said control process is a process of controlling each process, and can be suitably performed by a control means. The control means is not particularly limited as long as the movement of each process can be controlled, and can be appropriately selected according to the purpose. Examples thereof include devices such as a sequencer and a computer.

Here, the image forming apparatus of the present invention will be described with reference to the drawings. FIG. 3 is a schematic view showing an example of the image forming apparatus of the present invention.
Although the electrostatic latent image carrier 1 has a drum shape, it may be a sheet or an endless belt. Around the electrostatic latent image carrier 1, a pre-transfer charger 7 (transfer means), a transfer charger 10 (transfer means), a separation charger 11, and a pre-cleaning charger 15 are disposed as necessary. Known means such as a scorotron, a solid state charger (solid state charger), and a charging roller can be used.

As the charging means 3, a wire-type charger or a roller-type charger is used. When high speed charging is required, scorotron type chargers are used favorably. In compact and tandem type image forming apparatuses that use a plurality of electrostatic latent image carriers, acid gases (NOx, SOx, etc.) ) And roller-shaped chargers that generate less ozone. Although the electrostatic latent image carrier is charged by this charger, the higher the electric field strength applied to the electrostatic latent image carrier, the better the dot reproducibility. Therefore, an electric field of 20 V / μm or more. It is preferred that strength be applied. However, there is a possibility that problems such as dielectric breakdown of the photoreceptor and carrier adhesion during development may occur, and the upper limit is preferably 60 V / μm or less, and more preferably 50 V / μm or less.
The charging roller 3 (charging means) may be in contact with the photosensitive member, but by providing a suitable gap (approximately 10 μm to 200 μm) between them, the wear amount of both can be reduced. Toner filming on the charging member can be suppressed and can be preferably used. The voltage applied to the charging means is effective when the AC component is superimposed on the DC component in order to stabilize charging and suppress charging unevenness.
In general, the charger can be used as a transfer unit, but a transfer belt is also effective.
Further, as a light source such as an image exposure unit 5 (the device is not shown in FIG. 3), a static elimination lamp 2 (static elimination means), for example, a fluorescent lamp, a tungsten lamp, a halogen lamp, a mercury lamp, a sodium lamp, a light emitting diode (LED) In general, light emitting materials such as a semiconductor laser (LD) and electroluminescence (EL) can be used. Various types of filters such as a sharp cut filter, a band pass filter, a near infrared cut filter, a dichroic filter, an interference filter, and a color temperature conversion filter can be used to irradiate only light in a desired wavelength range. In addition to the steps shown in FIG. 3, these light sources are used for a transfer step, a static elimination step, a cleaning step, or a pre-exposure step in combination with light irradiation, and the electrostatic latent image carrier is irradiated with light. .
The toner developed on the electrostatic latent image carrier by the developing unit 6 (developing means) is transferred to a recording medium 9 such as transfer paper, but not all is transferred, but on the electrostatic latent image carrier. Some toner remains, and such toner is removed from the electrostatic latent image carrier by the fur brush 14 (cleaning means) and the cleaning blade 15 (cleaning means).
Although cleaning may be performed only with the cleaning blade of the present invention, a cleaning brush such as a fur brush may be used in combination as necessary.

The light source such as the static elimination lamp 2 is only required to neutralize the electrostatic latent image carrier, and can be appropriately selected from known static eliminators. For example, a semiconductor laser (LD), electroluminescence, etc. (EL) etc. are mentioned suitably.
In addition to the semiconductor laser (LD) and electroluminescence (EL), a fluorescent lamp, a tungsten lamp, a halogen lamp, a mercury lamp, a sodium lamp, a xenon lamp, or the like can be used. In order to specify the wavelength, various filters such as a sharp cut filter, a band pass filter, a near infrared cut filter, a dichroic filter, an interference filter, and a color temperature conversion filter can be used in combination with the light source.
In FIG. 3, 8 is a registration roller, and 12 is a separation claw.

  The image forming means in the image forming apparatus described above may be fixed in the copying apparatus, facsimile, or printer, but may be incorporated in the image forming apparatus in the form of a process cartridge described below.

(Process cartridge)
The process cartridge of the present invention includes an electrostatic latent image carrier, developing means for developing the electrostatic latent image with toner on the electrostatic latent image carrier to form a visible image, and the electrostatic latent image carrier. And at least cleaning means for removing the residual toner on the top, and further, other means such as charging means, exposure means, transfer means, and static elimination means as necessary.
The process cartridge can be detachably provided in various electrophotographic image forming apparatuses, facsimiles, and printers, and it is particularly preferable that the process cartridge is detachably provided in the image forming apparatus of the present invention.

Here, for example, as shown in FIG. 4, the process cartridge includes an electrophotographic photosensitive member 101, and includes a charging unit 102, a developing unit 104, a transfer unit 108, and a cleaning unit 107, and other units as necessary. It has the means of. In FIG. 4, reference numeral 103 denotes exposure by exposure means, and 105 denotes a recording medium.
Next, the image forming process using the process cartridge shown in FIG. 4 will be described. The electrophotographic photosensitive member 101 has its surface formed by charging by the charging means 102 and exposure 103 by the exposure means (not shown) while rotating in the direction of the arrow. Then, an electrostatic latent image corresponding to the exposure image is formed. The electrostatic latent image is developed by the developing unit 104, and the obtained visible image is transferred to the recording medium 105 by the transfer unit 108 and printed out. Next, the surface of the electrophotographic photosensitive member after the image transfer is cleaned by the cleaning unit 107 and further neutralized by a neutralizing unit (not shown), and the above operation is repeated again.

Examples of the present invention will be described below, but the present invention is not limited to these examples.
In the following synthesis examples, examples, and comparative examples, the number average molecular weight, the average circularity of the toner, and the volume average particle diameter of the toner were measured as follows.

<Number average molecular weight>
The number average molecular weight of the polysiloxane, diol, and polyurethane elastomer was measured by gel permeation chromatography (GPC). Incidentally, HLC-8220 (manufactured by Tosoh Techno System Co., Ltd.) was used, and measurement was performed using dimethylformamide as a solvent and polystyrene resin as a molecular weight calibration reagent.

<Volume average particle diameter of toner>
The volume average particle size of the toner was measured with a particle size measuring device (“Multisizer III”, manufactured by Beckman Coulter, Inc.) with an aperture diameter of 100 μm, and analyzed with analysis software (Beckman Coulter Multisizer 3 Version 3.51). .
Specifically, 0.5 ml of 10% by weight surfactant (alkylbenzene sulfonate Neogen SC-A, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) is added to a 100 ml glass beaker, and 0.5 g of each toner is added. The mixture was stirred with a micropartel, and then 80 ml of ion exchange water was added. The obtained dispersion was subjected to a dispersion treatment for 10 minutes with an ultrasonic disperser (W-113MK-II, manufactured by Honda Electronics Co., Ltd.). The dispersion was measured using the Multisizer III and Isoton III (manufactured by Beckman Coulter, Inc.) as the measurement solution. In the measurement, the toner sample dispersion was dropped so that the concentration indicated by the apparatus was 8 ± 2%. In this measurement method, it is important that the concentration is 8 ± 2% from the viewpoint of the reproducibility of the particle size. Within this concentration range, no error occurs in the particle size.

<Average circularity of toner>
The average circularity of the toner was measured using a flow type particle image analyzer (“FPIA-2100”, manufactured by Toa Medical Electronics Co., Ltd.). Specifically, 0.1 mL to 0.5 mL of a surfactant (alkylbenzene sulfonate) as a dispersant is added to 100 mL to 150 mL of water from which impure solids have been removed in advance, and each toner is further added. 0.1 g to 0.5 g was added and dispersed. The obtained dispersion liquid was subjected to a dispersion treatment for 1 minute to 3 minutes with an ultrasonic disperser (manufactured by Honda Electronics Co., Ltd.), and the shape and distribution of the toner were measured at a dispersion liquid concentration of 3,000 to 10,000 / μL. . The average circularity was calculated from these measurement results.

(Synthesis Example 1)
-Synthesis of polysiloxane (C-1) having three hydrolyzable alkoxy groups-
In Kolben, 100 parts by mass (0.74 mol) of methyltrimethoxysilane, 80 parts by mass (0.40 mol) of phenyltrimethoxysilane, 45 parts by mass of ion-exchanged water (2.5 mol), and 0. 1 part by mass (0.001 mol) was charged and heated and stirred at 60 ° C. for 6 hours. Further, by using an evaporator, methanol produced as a by-product by hydrolysis was removed over 2 hours under a reduced pressure of 50 mmHg. Polysiloxane (C-1) (number average molecular weight (Mn) = 2,800) was synthesized.

(Synthesis Example 2)
-Synthesis of polysiloxane (C-2) having two hydrolyzable alkoxy groups-
In Kolben, 170 parts by mass (0.74 mol) of diphenyldimethoxysilane, 80 parts by mass (0.40 mol) of phenyltrimethoxysilane, 40 parts by mass of ion-exchanged water (2.2 mol), and 0.1 oxalic acid A mass part (0.001 mol) was charged, and the mixture was heated and stirred at 60 ° C. for 6 hours. Further, by using an evaporator, methanol by-produced by hydrolysis was removed under reduced pressure of 50 mmHg over 2 hours. Polysiloxane (C-2) (number average molecular weight (Mn) = 5,000) was synthesized.

(Synthesis Example 3)
-Synthesis of polysiloxane (C-3) having three hydrolyzable alkoxy groups-
In Kolben, both ends carboxy group-modified polysiloxane ("X-22-162C", manufactured by Shin-Etsu Chemical Co., Ltd.) 50 parts by mass, γ-glycidoxypropyltrimethoxysilane 8 parts by mass, triphenylphosphine 1 part by mass And 0.2 parts by mass of p-methoxyphenol were charged and reacted at 110 ° C. for 10 hours to synthesize polysiloxane (C-3) (number average molecular weight (Mn) = 1,500).

(Comparative Synthesis Example 1)
-Synthesis of polysiloxane (C-4) having one hydrolyzable alkoxy group-
In Kolben, 119 parts by mass (1.14 mol) of trimethylmonomethoxysilane, 45 parts by mass (2.5 mol) of ion-exchanged water, and 0.1 part by mass (0.001 mol) of oxalic acid were charged at 60 ° C. The mixture was stirred under heating for 6 hours. Further, by using an evaporator, methanol produced as a by-product by hydrolysis was removed under reduced pressure of 50 mmHg over 2 hours to synthesize polysiloxane (C-4) (number average molecular weight (Mn) = 350) of Comparative Synthesis Example 1. did.

Example 1
-Preparation of cleaning blade-
1,000 parts by mass of polytetramethylene glycol (manufactured by Sanyo Chemical Industries, Ltd.) having a number average molecular weight (Mn) of 1,000, 198 parts by mass of diphenylmethane diisocyanate (manufactured by Nippon Polyurethane Co., Ltd.), and 1 part by mass of triethylamine as a catalyst. The mixture was charged into a four-necked flask and reacted at a reaction temperature of 100 ° C. for 6 hours to synthesize a prepolymer having isocyanate groups at both ends.
To this prepolymer, 36 parts by mass of 1,4-butanediol (molecular weight = 90) was added as a chain extender and reacted at 100 ° C. for 5 minutes.
To this, 250 parts by mass of polysiloxane (C-1) of Synthesis Example 1 and 0.1 part by mass of N- (trifluoromethylsulfonyloxy) succinimide as an acid generator were added and reacted at 100 ° C. for 3 hours. A polyurethane elastomer was produced as described above. The number average molecular weight (Mn) of the obtained polyurethane elastomer was 36,000.

  Next, the produced polyurethane elastomer was injection molded using an injection molding machine having a molding die. Specifically, the molding die is heated to 100 ° C. in advance, and a polyurethane elastomer is injected into the molding die in a state where a supporting member bonded with a vulcanizing adhesive is inserted into the die, Sixty seconds after injection, the molded cleaning blade was removed from the mold and subjected to secondary vulcanization for 20 hours with a circulating dryer at 100 ° C. Thereafter, edge cleaning was performed to produce the cleaning blade of Example 1.

(Example 2)
-Preparation of cleaning blade-
In Example 1, except that polytetramethylene glycol having a number average molecular weight (Mn) of 1,000 was changed to polytetramethylene glycol having a number average molecular weight (Mn) of 2,000 (manufactured by Sanyo Chemical Industries, Ltd.). The cleaning blade of Example 2 was produced in the same manner as Example 1.

(Example 3)
-Preparation of cleaning blade-
In Example 1, except that polytetramethylene glycol having a number average molecular weight (Mn) of 1,000 was changed to polytetramethylene glycol having a number average molecular weight (Mn) of 3,000 (manufactured by Sanyo Chemical Industries, Ltd.). A cleaning blade of Example 3 was produced in the same manner as Example 1.

Example 4
-Preparation of cleaning blade-
In Example 1, except that polytetramethylene glycol having a number average molecular weight (Mn) of 1,000 was changed to polytetramethylene glycol having a number average molecular weight (Mn) of 4,000 (manufactured by Sanyo Chemical Industries, Ltd.). A cleaning blade of Example 4 was produced in the same manner as Example 1.

(Example 5)
-Preparation of cleaning blade-
In Example 1, except that polytetramethylene glycol having a number average molecular weight (Mn) of 1,000 was changed to polytetramethylene glycol having a number average molecular weight (Mn) of 5,000 (manufactured by Sanyo Chemical Industries, Ltd.). A cleaning blade of Example 5 was produced in the same manner as Example 1.

(Example 6)
-Preparation of cleaning blade-
In Example 2, the cleaning blade of Example 6 was changed in the same manner as Example 2 except that the polysiloxane (C-1) of Synthesis Example 1 was changed to the polysiloxane (C-3) of Synthesis Example 3. Produced.

(Example 7)
-Preparation of cleaning blade-
In Example 2, except that the polysiloxane (C-1) of Synthesis Example 1 was changed to 50 parts by mass of the polysiloxane (C-2) of Synthesis Example 2, the same procedure as in Example 2 was repeated. A cleaning blade was produced.

(Example 8)
-Preparation of cleaning blade-
In Example 2, except that the polysiloxane (C-1) of Synthesis Example 1 was changed to 80 parts by mass of the polysiloxane (C-2) of Synthesis Example 2, the same procedure as in Example 2 was repeated. A cleaning blade was produced.

Example 9
-Preparation of cleaning blade-
In Example 2, except that the polysiloxane (C-1) of Synthesis Example 1 was changed to 530 parts by mass of the polysiloxane (C-2) of Synthesis Example 2, the same procedure as in Example 2 was repeated. A cleaning blade was produced.

(Example 10)
-Preparation of cleaning blade-
In Example 2, except that the polysiloxane (C-1) of Synthesis Example 1 was changed to 600 parts by mass of the polysiloxane (C-2) of Synthesis Example 2, the same procedure as in Example 2 was repeated. A cleaning blade was produced.

(Comparative Example 1)
-Preparation of cleaning blade-
In Example 1, except that polytetramethylene glycol having a number average molecular weight (Mn) of 1,000 was changed to polytetramethylene glycol (manufactured by Sanyo Chemical Industries, Ltd.) having a number average molecular weight (Mn) of 500, A cleaning blade of Comparative Example 1 was produced in the same manner as Example 1.

(Comparative Example 2)
-Preparation of cleaning blade-
In Example 1, except that polytetramethylene glycol having a number average molecular weight (Mn) of 1,000 was changed to polytetramethylene glycol having a number average molecular weight (Mn) of 6,000 (manufactured by Sanyo Chemical Industries, Ltd.). In the same manner as in Example 1, a cleaning blade of Comparative Example 2 was produced.

(Comparative Example 3)
-Preparation of cleaning blade-
In Example 3, the cleaning blade of Comparative Example 3 was the same as Example 3 except that the polysiloxane (C-1) of Synthesis Example 1 was changed to the polysiloxane (C-4) of Comparative Synthesis Example 1 Was made.

(Comparative Example 4)
-Preparation of cleaning blade-
A cleaning blade of Comparative Example 4 was produced in the same manner as in Example 3 except that the amount of polysiloxane (C-1) added in Synthesis Example 1 was changed to 0 part by mass in Example 3.

(Comparative Example 5)
-Preparation of cleaning blade-
A cleaning blade of Comparative Example 5 was produced in the same manner as in Example 3 except that the amount of N- (trifluoromethylsulfonyloxy) succinimide added as the acid generator in Example 3 was changed to 0 parts by mass. .

  Next, the constructions of the cleaning blades of Examples 1 to 10 and Comparative Examples 1 to 5 are summarized in Table 1.

＊ポリシロキサンの含有量は、ポリウレタンエラストマーの固形分質量に対する質量％を表す。

* Content of polysiloxane represents mass% with respect to solid mass of polyurethane elastomer.

(Production Example 1)
-Production of electrostatic latent image carrier-
A laminated photosensitive drum having a crosslinkable protective layer as an electrostatic latent image carrier used for evaluation was prepared.
First, an undercoat layer coating solution, a charge generation layer coating solution, and a charge transport layer coating solution having the following composition are sequentially applied on an aluminum cylinder having a diameter of 30 mm and dried to obtain a thickness of 3 An undercoat layer of 0.5 μm, a charge generation layer having a thickness of 0.2 μm, and a charge transport layer having a thickness of 23 μm were formed.
Next, a coating solution for a cross-linking protective layer having the following composition is spray-coated on the charge transport layer, and using a Fusion UV lamp system, bulb type: D bulb, lamp output: 200 W / cm, irradiation intensity : Light irradiation under the conditions of 2,200 mW / cm ² , irradiation time: 30 seconds, and further drying at 150 ° C. for 20 minutes to form a crosslinked protective layer having a thickness of 5 μm. Thus, an electrostatic latent image carrier for evaluation was produced.

(1) Coating liquid for undercoat layer-Alkyd resin (Beckosol 1307-60-EL, manufactured by Dainippon Ink and Chemicals, Inc.) ... 6 parts by mass-Melamine resin (Super Becamine G-821-60, large Made by Nippon Ink Chemical Co., Ltd.) ... 4 parts by mass-Titanium oxide ... 40 parts by mass-Methyl ethyl ketone ... 50 parts by mass

・ポリビニルブチラール（ＸＹＨＬ、ＵＣＣ社製）・・・０．５質量部
・シクロヘキサノン・・・２００質量部
・メチルエチルケトン・・・８０質量部 (2) Charge generation layer coating solution-Bisazo pigment represented by the following structural formula: 2.5 parts by mass

・ Polyvinyl butyral (XYHL, manufactured by UCC): 0.5 part by mass ・ Cyclohexanone: 200 part by mass ・ Methyl ethyl ketone: 80 part by mass

・テトラヒドロフラン・・・１００質量部
・シリコーンオイル（ＫＦ５０−１００ＣＳ、信越化学工業株式会社製）・・・０．００２質量部 (3) Coating liquid for charge transport layer-Bisphenol Z polycarbonate (Panlite TS-2050, manufactured by Teijin Chemicals Ltd.) ... 10 parts by mass-Charge transporting compound represented by the following structural formula: 7 parts by mass Part

Tetrahydrofuran ... 100 parts by mass Silicone oil (KF50-100CS, manufactured by Shin-Etsu Chemical Co., Ltd.) ... 0.002 parts by mass

・イルガキュア１８４（日本化薬株式会社製）・・・１質量部
・酢酸ブチル・・・８０質量部
・テトラヒドロフラン・・・４０質量部 (4) Coating liquid for crosslinking protective layer-Trimethylolpropane triacrylate (KAYARAD TMPTA, manufactured by Nippon Kayaku Co., Ltd.) ... 10 parts by mass-Charge transporting compound represented by the following structural formula ... 10 parts by mass Part

・ Irgacure 184 (manufactured by Nippon Kayaku Co., Ltd.) ・ ・ ・ 1 part by mass ・ Butyl acetate ... 80 parts by mass ・ Tetrahydrofuran ... 40 parts by mass

(Production Example 2)
-Preparation of toner-
A toner was prepared by a polymerization method.
The obtained toner (toner base particles) had an average circularity of 0.98 and a volume average particle size of 4.9 μm.
With respect to 100 parts by weight of the obtained toner base particles, 1.5 parts by weight of small particle size silica (manufactured by Clariant, H2000), 0.5 parts by weight of small particle size titanium oxide (manufactured by Teica, MT-150AI), and A toner for evaluation was prepared by externally adding 1.0 part by mass of silica with a large particle size (manufactured by Denki Kagaku Kogyo Co., Ltd., UFP-30H).

<Passing evaluation>
In the paper passing evaluation in Examples 1 to 10 and Comparative Examples 1 to 5, the evaluation electrostatic latent image carrier is mounted on a color multifunction peripheral (Imagio Neo C455, manufactured by Ricoh Co., Ltd.), and the evaluation toner is used. Then, the following conditions were evaluated under the following blade contact conditions. The results are shown in Table 2.

-Blade contact condition-
・ Line pressure: 20 g / cm
・ Cleaning angle: 78 degrees

-Evaluation environment-
・ Temperature 20 ℃, humidity 65% RH
・ Temperature 10 ℃, humidity 15% RH

-Paper feeding conditions-
-Image area ratio 5% chart-3 prints (A4 size side) / job-5,000 sheets at 20 ° C and humidity 65% RH, 5,000 sheets at 10 ° C and 15% humidity

<Poor cleaning>
The presence or absence of cleaning failure after completion of the paper passing evaluation in each evaluation environment was visually observed. The results are shown in Table 2.

<Abrasion amount of blade edge>
About the cleaning blade after completion | finish of paper passing evaluation, it observed with the ultra-deep shape measuring microscope (VK8500, product made by Keyence Corporation), and the magnitude | size of the abrasion amount was evaluated from the observed state. The results are shown in Table 2.

表２の結果から、実施例１〜１０では、１万枚通紙後もブレードエッジ摩耗量が少なく、通紙環境に依存しない良好なクリーニング性が達成できた。
これに対し、比較例１、２、３、及び５は、クリーニングブレードの機械特性が不十分であり、ブレードエッジ摩耗量がやや多くなっている。またブレードエッジの摩耗量が多いために帯状のクリーニング不良が発生した。
また、比較例４は、ポリウレタンエラストマーがポリシロキサンを含有していないため、機械特性が満足されておらず摩耗量が多くなっており、また低温環境下でのクリーニングブレード特性も変動しているために低温環境下で出力画像の全面に渡り明らかなクリーニング不良が発生した。
したがって静電潜像担持体表面に残留するトナーを除去するクリーニングブレードが、数平均分子量１，０００〜５，０００のジオール（Ａ）と、ジイソシアネート（Ｂ）と、２つ以上の加水分解性アルコキシ基を有するポリシロキサン（Ｃ）と、酸発生剤（Ｄ）とを反応させてなるポリウレタンエラストマーを含有してなるので、高い耐摩耗性と低温環境下でのクリーニング性の向上が両立でき、小粒径かつ球形のトナーを用いた場合でも、長期間に亘って高画質画像出力を実現できることが分かった。

From the results of Table 2, in Examples 1 to 10, the amount of blade edge wear was small even after 10,000 sheets were passed, and good cleaning performance independent of the paper passing environment could be achieved.
In contrast, in Comparative Examples 1, 2, 3, and 5, the mechanical properties of the cleaning blade are insufficient, and the blade edge wear amount is slightly increased. Also, due to the large amount of wear on the blade edge, a belt-like cleaning failure occurred.
Further, in Comparative Example 4, since the polyurethane elastomer does not contain polysiloxane, the mechanical properties are not satisfied, the wear amount is increased, and the cleaning blade characteristics in a low temperature environment also fluctuate. In particular, there was a clear cleaning defect over the entire output image in a low temperature environment.
Accordingly, the cleaning blade for removing the toner remaining on the surface of the electrostatic latent image carrier has a diol (A) having a number average molecular weight of 1,000 to 5,000, a diisocyanate (B), and two or more hydrolyzable alkoxy compounds. Since it contains a polyurethane elastomer obtained by reacting a polysiloxane (C) having a group and an acid generator (D), both high wear resistance and improvement in cleanability in a low temperature environment can be achieved. It was found that high-quality image output can be realized over a long period of time even when a toner having a particle size and a spherical shape is used.

  The cleaning blade of the present invention has a good cleaning property even when a toner having a small particle diameter and a spherical shape is used, and even in a low temperature environment, and exhibits high wear resistance, long life and high reliability. It is suitable for electrophotographic laser printers, digital copying machines, full-color copying machines, full-color laser printers, and the like.

FIG. 1 is a schematic sectional view showing an example of an electrostatic latent image carrier used in the image forming apparatus of the present invention. FIG. 2 is a schematic sectional view showing another example of the electrostatic latent image carrier used in the image forming apparatus of the present invention. FIG. 3 is a schematic view showing an example of the image forming apparatus of the present invention. FIG. 4 is a schematic view showing an example of the process cartridge of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Electrostatic latent image carrier 2 Static elimination lamp 3 Charger 5 Image exposure part 6 Developing unit 7 Charger before transfer 8 Registration roller 9 Transfer paper 10 Transfer charger 11 Separation charger 12 Separation claw 13 Charger before cleaning 14 Fur brush 15 Cleaning blade 101 Electrostatic latent image carrier 102 Charging means 103 Exposure means 104 Development means 105 Recording medium 106 Transfer means 107 Cleaning means 108 Static elimination means 201 Support body 202 Photosensitive layer 203 Charge generation layer 204 Charge transport layer 205 Protective layer

Claims (7)

A cleaning blade for removing toner remaining on the surface of the electrostatic latent image carrier,
The cleaning blade contains a polyurethane elastomer, and the polyurethane elastomer contains a diol (A) having a number average molecular weight of 1,000 to 5,000, a diisocyanate (B), and two or more hydrolyzable alkoxy groups. A cleaning blade obtained by reacting polysiloxane (C) having an acid generator (D). The cleaning blade according to claim 1, wherein the polysiloxane (C) is one or more condensates of a silane compound having a hydrolyzable alkoxy group represented by the following general formula (1).
R ¹ _m Si (OR ² ) _4-m ... General formula (1)
In the general formula (1), R ¹ represents any of saturated aliphatic hydrocarbon group and aromatic hydrocarbon group having 1 to 12 carbon atoms. R ² represents an alkyl group having 1 to 4 carbon atoms. m is an integer of 0-2.   The cleaning blade according to claim 1, wherein the number average molecular weight of the polysiloxane (C) is 500 to 6,000.   The cleaning blade according to any one of claims 1 to 3, wherein the content of the polysiloxane (C) is 5% by mass to 30% by mass with respect to the solid content mass of the polyurethane elastomer. An electrostatic latent image forming step of forming an electrostatic latent image on the electrostatic latent image carrier, a developing step of developing the electrostatic latent image with toner to form a visible image, and the visible image The image forming method includes at least a transfer step for transferring the toner image to a recording medium, a fixing step for fixing the transferred image transferred to the recording medium, and a cleaning step for removing residual toner on the surface of the electrostatic latent image carrier. And
An image forming method, wherein the cleaning step is performed using the cleaning blade according to claim 1. An electrostatic latent image carrier, electrostatic latent image forming means for forming an electrostatic latent image on the electrostatic latent image carrier, and developing the electrostatic latent image with toner to form a visible image Developing means, transfer means for transferring the visible image to a recording medium, fixing means for fixing the transferred image transferred to the recording medium, and cleaning means for removing residual toner on the surface of the electrostatic latent image carrier An image forming apparatus having at least
An image forming apparatus, wherein the cleaning unit includes the cleaning blade according to claim 1. An electrostatic latent image carrier, developing means for developing the electrostatic latent image formed on the electrostatic latent image carrier using toner to form a visible image, and residual toner on the surface of the electrostatic latent image carrier A process cartridge having at least cleaning means for removing
5. A process cartridge, wherein the cleaning means has the cleaning blade according to claim 1.

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