JP4426597B2 - Cleaning blade for image forming apparatus - Google Patents

Description

  The present invention relates to a cleaning blade for an image forming apparatus, and more particularly, a thermosetting elastomer composition having excellent resilience, including a rubber component (1), a filler (2), a crosslinking agent (3) and a dispersion improver (4). The present invention relates to a cleaning blade for an image forming apparatus which is molded from a product and has excellent wear resistance and cleaning performance.

  In an electrostatic photographic copying machine using plain paper as recording paper, generally, an electrostatic charge is applied to the surface of the photoreceptor by electric discharge, and an image is exposed thereon to form an electrostatic latent image. Copy the toner by attaching the toner to the electrostatic latent image, developing it, transferring the toner image onto the recording paper, and finally heating and pressing the recording paper onto which the toner image has been transferred, and fixing the toner onto the recording paper. It is carried out. Therefore, in order to sequentially copy on a plurality of recording papers, it is necessary to remove the toner remaining on the surface of the photosensitive member after transferring the toner image from the photosensitive member to the recording paper in the above-described process. As one of the removal methods, there is known a blade cleaning method in which a cleaning blade is pressed against the surface of the photosensitive member and the photosensitive member is slid in contact with the cleaning member.

Conventionally, a cleaning blade made of polyurethane rubber has been widely used as a cleaning blade for an image forming apparatus used in this method.
For example, Japanese Patent Laid-Open No. 2000-75743 (Patent Document 1) discloses a cleaning blade for an electrophotographic apparatus having a blade member made of polyurethane having a JIS A hardness of 62-80 at 23 ° C. and a rebound resilience of 5-15%. Are listed.

However, the cleaning blade made of polyurethane rubber has low heat resistance, and there is a problem that the edge portion of the cleaning blade is worn and rounded due to friction with the photoreceptor, and the toner cannot be removed. In particular, the blade member described in Patent Document 1 has a low rebound resilience of 5 to 15%, and the cleaning performance is exhibited by the clogging action by keeping the blade member in close contact with the surface of the photoreceptor. Part wear is more prominent.
On the other hand, if the wear amount is to be suppressed, there is a problem that the ground pressure (hereinafter referred to as linear pressure) between the cleaning blade and the photosensitive member is lowered and defective cleaning occurs. Conventional pulverized toner and deformed polymerized toner are easy to remove, and poor cleaning was not a problem even at low linear pressure. However, due to the trend of energy saving, low cost, and high image quality in recent years, small particle size As a result of the development of the spherical polymer toner, it is difficult to remove the remaining toner unless the linear pressure of the cleaning blade is increased, and cleaning defects are likely to occur.

JP 2000-75743 A JP 2001-187167 A JP 2003-33447 A JP 2003-38682 A

  The present invention is excellent in wear resistance at the edge portion, and therefore can be set to a high contact pressure with a member to be cleaned such as a photoreceptor, and as a result, even for small particle size / spherical polymerization toner that is difficult to remove. An object of the present invention is to provide a cleaning blade for an image forming apparatus that can exhibit excellent cleaning performance.

（式中、Ｘはフルオロ基を除く置換基を表わし、ｋは０〜５の整数を表わす。）
で示される化合物、または／および、下記式（２）；

（式中、Ｙ、Ｚは置換基を表わし、ｌおよびｍは０〜５の整数を表わし、ｎは自然数を表わす。）
で示される化合物を、ゴム成分１００質量部に対し０．０５〜１３質量部の割合で含むことを特徴としている。 In order to solve the above problems, the present invention provides a rubber component composed of a mixture of NBR or HNBR with zinc methacrylate, or a mixture of HNBR and HNBR in which zinc methacrylate is finely dispersed.
One or two dispersion improvers selected from benzenethiol, diphenyl disulfide, bis (pentabromophenyl) disulfide, and 4-fluorothiophenol zinc salt are added in an amount of 0.05 to 13.3 with respect to 100 parts by mass of the rubber component. An image forming apparatus comprising 0 part by mass, molded from a thermosetting elastomer composition vulcanized with a crosslinking agent comprising an organic peroxide, and having a tensile strength of 35 to 55 MPa measured according to JIS K 6251 Provides a cleaning blade .
That is, a cleaning blade for an image forming apparatus molded from a thermosetting elastomer composition containing a rubber component (1), a filler (2) made of zinc methacrylate , a crosslinking agent (3) and a dispersion improver (4). It is.
As the dispersion improver (4), the following formula (1);

(In the formula, X represents a substituent other than a fluoro group, and k represents an integer of 0 to 5.)
Or / and the following formula (2);

(In the formula, Y and Z represent substituents, l and m represent integers of 0 to 5, and n represents a natural number.)
The compound represented by in, 100 parts by mass of the rubber component to is characterized by a proportion of 0.05 3 parts by weight.

（式中、Ｆはフルオロ基を表わし、ｊは１〜５の整数を表わす。）
で示される化合物または／及び該化合物の金属塩を配合している。 Alternatively, as the dispersion improver (4), the following formula (3);

(In the formula, F represents a fluoro group, and j represents an integer of 1 to 5.)
Or / and a metal salt of the compound.

As a result of intensive studies on the wear resistance of the edge portion, the present inventor has shown that the wear resistance of the edge portion can be improved by using a thermosetting elastomer composition having a high rebound resilience, preferably a rebound resilience of 50 to 70%. It has been found that it can be improved.
Here, in Patent Document 1, in a polyurethane blade member having a rebound resilience of 20 to 60%, when the toner is fused in the form of a film on the surface of the photosensitive member like a fused toner, the cleaning property is lowered. It has been pointed out. However, if the wear resistance of the edge portion can be improved by using a thermosetting elastomer composition having a high rebound resilience, it becomes possible to set the contact pressure between the cleaning blade and the photoreceptor high. Even the fused toner can be sufficiently removed.

Obtaining such knowledge, the present inventor has intensively studied to improve the rebound resilience of the thermosetting elastomer composition constituting the cleaning blade, and as a result, the thiol and / or sulfide having a specific chemical structure has been described above. By blending as the dispersion improver (4), the dispersibility of the filler (2) was improved, and the rebound resilience of the thermosetting elastomer composition could be improved.
In JP-A-2001-187167 (Patent Document 2), JP-A-2003-33447 (Patent Document 3) and JP-A-2003-38682 (Patent Document 4), it is represented by the chemical formula (1). A rubber composition containing a thiol, a sulfide represented by the chemical formula (2), and a fluorine-substituted benzenethiol (fluorine-substituted thiophenol) represented by the chemical formula (3) is described. However, the inventions described in the three known documents are inventions related to the core of the golf ball, and the three known documents do not describe or suggest the cleaning blade for the image forming apparatus. As a matter of course, there is no description or suggestion about the relationship between the resilience elastic modulus, the wear resistance and the linear pressure in the cleaning blade for an image forming apparatus as discovered by the present inventor, and thus the cleaning performance. .

Below, each component contained in the thermosetting elastomer composition which comprises the cleaning blade for image forming apparatuses of this invention is explained in full detail.
In the thiol represented by the chemical formula (1) or the sulfide represented by the chemical formula (2), the hydrogen of the phenyl group may be substituted with substituents represented by X, Y, and Z. In chemical formula (1) and chemical formula (2), the number of substituents X, the number of substituents Y, and the number of substituents Z are represented by k, l, and m, respectively, depending on the types of substituents X, Y, and Z. It takes an integer of 1 to 5 that is chemically acceptable. When the phenyl group is not modified by the substituents X, Y, and Z, k, l, and m are each 0. When k is an integer of 2 or more, a plurality of substituents X are present, and each of the plurality of substituents X may be the same or different. The same applies to the substituent Y and the substituent Z.

The substituent X, substituent Y or substituent Z may be various substituents as long as it is chemically acceptable. Specifically, for example, (i) a halogen atom (for example, fluorine, chlorine, bromine) and iodine, provided that fluorine is excluded as a substituent X), (ii) nitro group, (iii) cyano group, (iv) a carboxyl group, (v) C ₁ - ₆ alkoxy - carbonyl group (e.g. methoxycarbonyl, ethoxycarbonyl, carbonyl, tert- butoxycarbonyl etc.), (vi) hydroxy group, (vii) C ₁ - ₃ alkylenedioxy group (e.g. methylenedioxy, ethylenedioxy, etc.), optionally C ₁ be (viii) halogenated - ₆ alkyl group (e.g. methyl, ethyl, propyl, isopropyl, n- butyl, isobutyl, sec- butyl, tert- butyl, trifluoromethyl, etc.), is (ix) a halogenated There may be _{C 1} - ₆ alkoxy group (e.g. methoxy, ethoxy, propoxy, isopropoxy, n- butoxy, isobutoxy, sec- butoxy, tert- butoxy, etc.), (x) a benzyl group, (xi) a phenyl group, ( xii) benzoyl group, (xiii) a phenoxy group, (xiv) amino, (xv) mono - or di -C ₁ - ₆ alkylamino group (e.g. methylamino, ethylamino, dimethylamino, diethylamino, methyl-ethylamino) , (xvi) C ₁ - ₆ alkylaminocarbonyl group, (xvii) carbamoyl group, (xviii) C ₁ - ₆ alkyl - group (e.g. methylcarbonyl, ethylcarbonyl, butylcarbonyl and the like), (xix) a halo C ₁ - _{A 6-} alkyl-carbonyl group and the like.
As the substituent X, substituent Y or substituent Z, (i) a halogen atom, (ii) a nitro group, and (iii) a cyano group are preferable. However, the substituents Y and Z may be fluorine, but fluorine is excluded as the substituent X.

  In chemical formula (2), n represents a natural number, preferably an integer of 2 or more, and more preferably 2.

Specifically, as the thiol represented by the chemical formula (1), thiophenols such as benzenethiol (thiophenol), 4-chlorobenzenethiol, 3-chlorobenzenethiol, 4-bromobenzenethiol, 3-bromobenzenethiol, 4-iodobenzenethiol, 2,5-dichlorobenzenethiol, 3,5-dichlorobenzenethiol, 2,6-dichlorobenzenethiol, 2,5-dibromobenzenethiol, 3,5-dibromobenzenethiol, 2-chloro- 5-bromobenzenethiol, 2,4,6-trichlorobenzenethiol, 2,3,4,5,6-pentachlorobenzenethiol, 4-cyanobenzenethiol, 2-cyanobenzenethiol, 4-nitrobenzenethiol, 2-nitrobenzene Thiol etc. It is.
Among them, benzenethiol, 4-chlorobenzenethiol, 4-bromobenzenethiol, 4-iodobenzenethiol, 2,5-dichlorobenzenethiol, 3,5-dichlorobenzenethiol, 2-chloro-5-bromobenzenethiol, 2,4,5-trichlorobenzenethiol, 2,3,4,5,6-pentachlorobenzenethiol and the like are preferable.
In the present invention, as described above, benzenethiol is used .

  Specific examples of the sulfide represented by the chemical formula (2) include diphenyl disulfide, bis (4-chlorophenyl) disulfide, bis (3-chlorophenyl) disulfide, bis (4-bromophenyl) disulfide, and bis (3-bromophenyl). Disulfide, bis (4-fluorophenyl) disulfide, bis (4-iodophenyl) disulfide, bis (2,5-dichlorophenyl) disulfide, bis (3,5-dichlorophenyl) disulfide, bis (2,6-dichlorophenyl) disulfide, Bis (2,5-dibromophenyl) disulfide, bis (3,5-dibromophenyl) disulfide, bis (2-chloro-5-bromophenyl) disulfide, bis (2,4,6-trichlorophenyl) disulfide, bis ( 2, 4, -Tribromophenyl) disulfide, bis (tetrabromophenyl) disulfide, bis (2,3,4,5,6-pentachlorophenyl) disulfide, bis (2,3,4,5,6-pentafluorophenyl) disulfide, Bis (2,3,4,5,6-pentabromophenyl) disulfide, bis (4-cyanophenyl) disulfide, bis (2-cyanophenyl) disulfide, bis (4-nitrophenyl) disulfide, bis (2-nitro Phenyl) disulfide and the like.

Among them, diphenyl disulfide, bis (4-chlorophenyl) disulfide, bis (4-fluorophenyl) disulfide, bis (4-iodophenyl) disulfide, bis (2,5-dichlorophenyl) disulfide, bis (3,5-dichlorophenyl) Disulfide, bis (2-chloro-5-bromophenyl) disulfide, bis (2,4,5-trichlorophenyl) disulfide, bis (2,3,4,5,6-pentachlorophenyl) disulfide, bis (2,3 , 4,5,6-pentafluorophenyl) disulfide, bis (2,3,4,5,6-pentachlorophenyl) sulfide, bis (2,3,4,5,6-pentafluorophenyl) sulfide and the like are preferable. .
In the present invention, as described above, diphenyl disulfide is used.

  Moreover, as a sulfide represented by the chemical formula (2), a compound in which at least one of the substituent Y and the substituent Z is a bromo group (Br) can be mentioned as a preferred embodiment. Particularly preferably, three or more of the substituent Y and three or more of the substituent Z are Br, and most preferably, the substituent Y and the substituent Z are all Br.

Specific examples of the compound in which at least one of substituent Y and substituent Z is a bromo group (Br) include bis (bromophenyl) disulfide, bis (dibromophenyl) disulfide, bis (tribromophenyl) disulfide, bis (tetrabromophenyl) disulfide, bis (pentabromophenyl) disulfide and the like is not preferable.
In the present invention, bis (pentabromophenyl) disulfide is used as described above.

The fluorine-substituted benzenethiol represented by the chemical formula (3) has at least one of the substituents X of the benzenethiol represented by the chemical formula (1) as a fluoro group (F).
Off Tsu containing substituted benzenethiol also, in addition to improving the dispersibility of the co-crosslinking agent, used in order to improve the rebound resilience as compared to the same hardness of the cleaning blade. That is, among the benzenethiol (thiophenol) compounds, the fluorine-substituted benzenethiol or / and its metal salt represented by the chemical formula (3) can exhibit particularly excellent resilience regardless of the magnitude of the vibration of the cleaning blade. . Therefore, a cleaning blade having the same rebound resilience can be achieved with a more flexible cleaning blade, so that a large nip width can be obtained while improving wear resistance, and excellent cleaning performance can be obtained. it can.
As described above, the cleaning blade using the thermosetting elastomer composition using the fluorine-substituted benzenethiol or / and its metal salt represented by the chemical formula (3) has a substituent other than the fluoro group represented by the chemical formula (1). Since there is a difference in physical properties from those using benzenethiol having a sulfite or a sulfide represented by the chemical formula (2), it is defined separately from the chemical formula (1). However, the fluorine-substituted benzenethiol represented by the chemical formula (3) is not prevented from being mixed with the thiol represented by the chemical formula (1) or / and the sulfide represented by the chemical formula (2). total amount of the dispersion-improving agent (4) of the case, the rubber component (1) 0.05 3 parts by weight to 100 parts by weight, but is preferably 0.05 to 10 parts by weight.

The fluorine-substituted benzenethiol represented by the chemical formula (3) includes fluorobenzenethiol (fluorothiophenol), difluorobenzenethiol (difluorothiophenol), trifluorobenzenethiol (trifluorothiophenol), tetrafluorobenzenethiol (tetrafluoro Thiophenol) and pentafluorobenzenethiol (pentafluorothiophenol) .

Examples of the metal salt of fluorine-substituted benzenethiol represented by the chemical formula (3) include monovalent metal salts such as sodium and lithium of the fluorine-substituted benzenethiol represented by the chemical formula (3), and divalent metals such as zinc and magnesium. metal salt is Ru and the like.
Specifically, fluorobenzene thiol zinc salt, difluorobenzene thiol zinc salt, trifluorobenzene thiol zinc salt, tetrafluorobenzene thiol zinc salt, pentafluorobenzene thiol zinc salt, pentafluorobenzene thiol sodium salt, fluorobenzene thiol magnesium salt , Difluorobenzene thiol magnesium salt, trifluorobenzene thiol magnesium salt, tetrafluorobenzene thiol magnesium salt, pentafluorobenzene thiol magnesium salt and the like.

As the dispersion-improving agent (4), when using a sulfide represented by the thiol or / and Formula represented by Formula (1) (2), the amount thereof, 100 parts by mass of the rubber component to 0.05 3 Part by mass. When the blending amount of the dispersion improver (4) is less than 0.05 parts by mass, the dispersibility of other components, particularly the filler (2), is deteriorated. On the other hand, even beyond the amount of 1 3 parts by weight of the dispersion-improving agent (4), the other components in the reverse, particularly the dispersibility of the filler (2) deteriorates. In either case, the rebound resilience decreases due to the deterioration of dispersibility.

On the other hand, when the fluorine-substituted benzenethiol or / and metal salt thereof represented by the chemical formula (3) is used as the dispersion improver (4), the blending amount is 0.05 to 100 parts by mass with respect to 100 parts by mass of the rubber component. It is 10 mass parts, More preferably, it is 0.05-5 mass parts. This is because when the blending amount of the fluorine-substituted benzenethiol with respect to 100 parts by mass of the rubber component exceeds 10 parts by mass, unreacted fluorine-substituted benzenethiol is interposed, the physical property value is lowered, and the desired resilience cannot be achieved. It is. When the blending amount of the dispersion improver (4) is less than 0.05 parts by mass, the dispersibility of other components, particularly the filler (2), is deteriorated.
As described above, when the fluorine-substituted benzenethiol or / and metal salt thereof represented by the chemical formula (3) is used, the thiol represented by the chemical formula (1) or / and the sulfide represented by the chemical formula (2) is used. The upper limit of the blending amount is lower because the former is easier to obtain a thermosetting elastomer composition having a higher impact resilience with a smaller blending amount than the latter, and is highly reactive and unreacted. This is because if it remains, the physical properties may be deteriorated.

Examples of the rubber component (1) include acrylonitrile butadiene rubber , acrylonitrile-butadiene rubber having a carboxyl group introduced, hydrogenated acrylonitrile butadiene rubber, acrylonitrile-butadiene rubber having a carboxyl group introduced and hydrogenated, natural rubber, butadiene rubber, styrene butadiene Examples thereof include rubber, isoprene rubber, butyl rubber, chloroprene rubber, acrylic rubber, epichlorohydrin rubber, ethylene propylene rubber, and ethylene-propylene-diene copolymer rubber.
In the present invention, the acrylonitrile butadiene rubber and the hydrogenated acrylonitrile butadiene rubber are used.

The rubber component (1) is a mixture of two types .
2 kinds of rubber, 90 to 50 parts by weight the amount of the rubber component to the total mass of one When 100 parts by weight rubber (referred to as "rubber A"), preferably with 90 to 70 parts by weight, the other The compounding amount of rubber (referred to as “rubber B”) is 10 to 50 parts by mass, preferably 10 to 30 parts by mass.
The reason why the blending amount of the rubber A is 50 parts by mass or more and 90 parts by mass or less is that if the blending amount of the rubber A is less than 50 parts by mass, the physical strength may be lowered. It is because there exists a possibility that the performance of rubber | gum B may not be exhibited when a compounding quantity exceeds 90 mass parts.
The reason why the blending amount of the rubber B is 10 parts by mass or more and 50 parts by mass or less is that if the blending amount of the rubber B is less than 10 parts by mass, the performance of the rubber B may not be exhibited. It is because there exists a possibility that the physical strength based on the rubber A may fall when the compounding quantity of exceeds 50 mass parts.

As described above, the rubber component (1) is a nitrile group-containing copolymer rubber .
A nitrile group-containing copolymer rubber is a rubber obtained by copolymerizing an α, β-ethylenically unsaturated nitrile monomer with another monomer. Acrylonitrile is used as the α , β-ethylenically unsaturated nitrile monomer, and the content of the α 1 , β-ethylenically unsaturated nitrile monomer unit is 10 to 60% by mass, preferably 12 to 55% by mass. More preferably, it is 15-50 mass%.
Examples of the monomer to be copolymerized with the α, β-ethylenically unsaturated nitrile monomer include conjugated diene monomer, non-conjugated diene monomer, α-olefin and the like. Among them, conjugated diene monomer Is preferred. These monomers, aromatic vinyl monomers, fluorine-containing vinyl monomers, α, β-ethylenically unsaturated monocarboxylic acids, α, β-ethylenically unsaturated polycarboxylic acids or their anhydrides Etc. may be used in combination.
Examples of the conjugated diene monomer include 1,3-butadiene, isoprene, 2,3-dimethyl-1,3-butadiene, and 1,3-pentadiene. Among them, 1,3-butadiene is preferable.

The nitrile group-containing copolymer rubber includes a hydrogenated rubber obtained by hydrogenating the carbon-carbon unsaturated bond of the nitrile group-containing copolymer rubber by a known method. Among these, a hydrogenated rubber having a residual double bond of 30% or less is preferable, and a hydrogenated rubber having a residual double bond of 10% or less is more preferable.
Further, the nitrile group-containing copolymer rubber includes a rubber in which a carboxyl group is introduced into the nitrile group-containing copolymer rubber or its hydrogenated rubber.

  Specific examples of the nitrile group-containing copolymer rubber include acrylonitrile-butadiene rubber, acrylonitrile-isoprene rubber, acrylonitrile-butadiene-acrylate rubber or acrylonitrile-butadiene-acrylate-methacrylic acid rubber, hydrogenated rubber of these rubbers, or these rubbers. Examples thereof include rubber having a carboxyl group introduced therein.

In the present invention, as described above, acrylonitrile butadiene rubber (hereinafter referred to as NBR) or / and hydrogenated acrylonitrile butadiene rubber (hereinafter referred to as HNBR) are used as the rubber component (1) . In particular, it is most preferable to use HNBR having a residual double bond of 10% or less.
NBR or HNBR has the characteristics of high tensile strength and tear strength and excellent fracture resistance. In addition, since uniform crosslink density can be realized and edge wear can be made uniform, stress concentration due to uneven wear of the edge unlike conventional polyurethane cleaning blades does not occur, and good cleaning performance is demonstrated. can do.

NBR used as a raw material for NBR or HNBR is low nitrile NBR having a bound acrylonitrile content of 25% or less, medium nitrile NBR having a bound acrylonitrile content of 25% to 31%, and a bound acrylonitrile content of 31% to 36%. Either medium-high nitrile NBR or high nitrile NBR having a combined acrylonitrile amount of 36% or more may be used.
Among these, as NBR, it is more preferable to use medium-high nitrile NBR having an acrylonitrile content of 31 to 35% and high nitrile NBR having an acrylonitrile content of 36 to 50%.
Further, as the HNBR, it is more preferable to use HNBR having a bound acrylonitrile amount of 21% to 46% and a Mooney viscosity ML1 + 4 (100 ° C.) of 20 to 160. If the amount of bonded acrylonitrile is less than 21%, the mechanical properties are lowered. On the other hand, if the amount of bonded acrylonitrile exceeds 46%, the glass transition temperature Tg of the thermosetting elastomer is increased and the cleaning performance at low temperature and low humidity tends to be deteriorated. The amount of bound acrylonitrile in HNBR is more preferably 21% to 44%, and still more preferably 31 to 35%. Further, if the Mooney viscosity ML1 + 4 (100 ° C.) of HNBR is less than 20, the molecular weight tends to decrease and the wear resistance tends to deteriorate. On the other hand, if the Mooney viscosity ML1 + 4 (100 ° C.) of HNBR exceeds 160, kneading occurs from an excessive molecular weight distribution. And molding becomes difficult. The Mooney viscosity ML1 + 4 (100 ° C.) of HNBR is more preferably 40 to 150. The Mooney viscosity is measured according to JIS K 6300.

  The rubber component (1) is preferably composed of only NBR and / or HNBR, but other rubbers may be combined as desired. As the other rubber, any of the rubbers exemplified above may be used, and among them, butadiene rubber or styrene butadiene rubber is preferably used.

As the rubber component (1), those in which components other than the rubber component (1) contained in the thermosetting elastomer composition constituting the cleaning blade of the present invention are finely dispersed in the rubber can also be used.
In the rubber of the embodiments, the rubber as a base polymer, are used N B R Contact and HNBR.
As the component other than the rubber component (1) to be finely dispersed, the filler (2) is preferable, and among the filler (2), a co-crosslinking agent is more preferable. Among the co-crosslinking agents, α, β-unsaturated carboxylic acid Metal salts are particularly preferred. By highly finely dispersing the co-crosslinking agent in the rubber, the finely-dispersed co-crosslinking agent undergoes a polymerization / grafting reaction at the time of crosslinking to form a fine structure, thereby realizing higher mechanical properties.

The thermosetting elastomer composition constituting the cleaning blade of the present invention uses a co-crosslinking agent as the filler (2), and also includes a vulcanization accelerator, a vulcanization accelerator, an anti-aging agent, a rubber softener, It is preferable to include one or more selected from the group consisting of reinforcing agents and other additives.
The filler (2) is preferably blended in an amount of 0.1 to 80 parts by mass with respect to 100 parts by mass of the rubber component (1). This is because if the blending amount of the filler (2) is less than 0.1 parts by mass, the rubber component may not be sufficiently reinforced or vulcanized. On the other hand, if the blending amount of the filler (2) exceeds 80 parts by mass, the hardness becomes too high and the image forming apparatus cleaning blade of the present invention may damage the photoconductor.

The co-crosslinking agent is a generic term for those which themselves crosslink and also react with rubber molecules to crosslink and polymerize the whole.
The amount of the co-crosslinking agent may be an amount sufficient for the rubber component to be vulcanized, and is usually 0 to 20 parts by mass, preferably 0.1 to 10 parts by mass with respect to 100 parts by mass of the rubber component. Selected from a range.
Examples of the co-crosslinking agent include methacrylic acid esters, ethylenically unsaturated monomers typified by metal salts of methacrylic acid or acrylic acid, polyfunctional polymers using functional groups of 1,2-polybutadiene, or dioxime. In the present invention, zinc methacrylate is used.

As an ethylenically unsaturated monomer,
(A) monocarboxylic acids such as acrylic acid, methacrylic acid, crotonic acid,
(B) dicarboxylic acids such as maleic acid, fumaric acid, itaconic acid,
(C) an ester or anhydride of the unsaturated carboxylic acids of (a) and (b),
(D) a metal salt of (a) to (c),
(E) aliphatic conjugated dienes such as 1,3-butadiene, isoprene, 2-chloro-1,3-butadiene,
(F) aromatic vinyl compounds such as styrene, α-methylstyrene, vinyl toluene, ethyl vinyl benzene, divinyl benzene,
(G) vinyl compounds having a heterocyclic ring such as triallyl isocyanurate, triallyl cyanurate, vinylpyridine,
(H) Other examples include vinyl cyanide compounds such as (meth) acrylonitrile or α-chloroacrylonitrile, acrolein, formylstyrene, vinyl methyl ketone, vinyl ethyl ketone, and vinyl butyl ketone.

Examples of “esters of monocarboxylic acids” in (c) include methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, i-propyl (meth) acrylate, and n-butyl (meth) acrylate. , I-butyl (meth) acrylate, n-pentyl (meth) acrylate, i-pentyl (meth) acrylate, n-hexyl (meth) acrylate, cyclohexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, octyl (meth) ) Acrylate, i-nonyl (meth) acrylate, tert-butylcyclohexyl (meth) acrylate, decyl (meth) acrylate, dodecyl (meth) acrylate, hydroxymethyl (meth) acrylate, hydroxyethyl (meth) acrylate Alkyl esters of (meth) acrylic acid;
Aminoalkyl esters of (meth) acrylic acid such as aminoethyl acrylate, dimethylaminoethyl acrylate, butylaminoethyl acrylate;
(Meth) acrylate having an aromatic ring such as benzyl (meth) acrylate, benzoyl (meth) acrylate, allyl (meth) acrylate;
(Meth) acrylates having an epoxy group such as glycidyl (meth) acrylate, metaglycidyl (meth) acrylate, and epoxycyclohexyl (meth) acrylate;
(Meth) acrylates having various functional groups such as N-methylol (meth) acrylamide, γ- (meth) acryloxypropyltrimethoxysilane, tetrahydrofurfuryl methacrylate;
Polyfunctional (meth) acrylates such as ethylene glycol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, ethylene dimethacrylate (EDMA), polyethylene glycol dimethacrylate, isobutylene ethylene dimethacrylate;
Etc.

Examples of the “esters of dicarboxylic acids” in (c) include half esters such as methyl maleate or methyl itaconate, diallyl phthalates, and diallyl itaconates.
Examples of the “anhydride of unsaturated carboxylic acids” in (c) include acrylic acid anhydride and maleic acid anhydride.

  Examples of the “metal salt” in (d) include sodium salts, aluminum salts, calcium salts, zinc salts, magnesium salts, and the like of unsaturated carboxylic acids such as acrylic acid, methacrylic acid, maleic acid or fumaric acid. Can be mentioned.

The d ethylenic unsaturated monomer,
Methacrylic acid;
Methacrylic acid higher esters such as trimethylolpropane trimethacrylate (TMPT), ethylene dimethacrylate (EDMA), polyethylene glycol dimethacrylate, cyclohexyl methacrylate, allyl methacrylate, tetrahydrofurfuryl methacrylate or isobutylene ethylene dimethacrylate;
Metal salts of α, β-unsaturated carboxylic acids such as zinc salts such as acrylic acid, methacrylic acid, fumaric acid or maleic acid, sodium salts, magnesium salts, calcium salts, aluminum salts;
Examples include triallyl isocyanurate, triallyl cyanurate, diallyl phthalate, diallyl itaconate, vinyl toluene, vinyl pyridine, and divinyl benzene.
In particular, a metal salt of methacrylic acid or α, β-unsaturated carboxylic acid is more preferable, and a metal salt of α, β-unsaturated carboxylic acid is more preferably a metal salt of methacrylic acid or acrylic acid.
The metal salt of methacrylic acid or acrylic acid, aluminum acrylate, aluminum methacrylate, zinc acrylate, zinc methacrylate, calcium acrylate, calcium methacrylate, magnesium acrylate, Ru magnesium methacrylate, and the like. It is most preferred damage using main methacrylic acid zinc is used in the present invention the zinc methacrylate.

Examples of the polyfunctional polymers include polyfunctional polymers using a functional group of 1,2-polybutadiene, and more specifically include Buton 150, Buton 100, polybutadiene R-15, Diene-35, and Hystal-B2000. Can be mentioned.
Examples of the dioxime include p-quinone dioxime, p, p′-dibenzoylquinone dioxime, and N, N′-m-phenylenebismaleimide.

As the vulcanization accelerator, either an inorganic accelerator or an organic accelerator can be used.
Examples of the inorganic accelerator include slaked lime, magnesium oxide, titanium oxide, or resurge (PbO).
Examples of the organic accelerator include thylliums, thiazoles, thioureas, dithiocarbamates, guanidines, sulfenamides, and the like.
Examples of the thyriums include tetramethyl thylium monosulfide, tetramethyl thyrium disulfide, tetraethyl thyrium disulfide, tetrabutyl tyrium disulfide, dipentamethylene tyrium tetrasulfide, and the like.
Examples of thiazoles include 2-mercaptobenzothiazole, benzothiazyl disulfide, N-cyclohexylbenzothiazole and the like.
The thioureas, N, N'-diethyl thiourea, and ethylene thiourea or preparative trimethyl thiourea and the like.
Dithiocarbamate salts include zinc dimethyldithiocarbamate, zinc diethyldithiocarbamate, zinc dibutyldithiocarbamate, sodium dimethyldithiocarbamate, sodium diethyldithiocarbamate, copper dimethyldithiocarbamate, dimethyldithiothiol Examples thereof include iron (III) carbamate, selenium ethyldithiocarbamate, and tellurium diethyldithiocarbamate.
Examples of the guanidine accelerator include di-o-tolylguanidine, 1,3-diphenylguanidine, 1-o-tolylbiguanide, dicatechol borate di-o-tolylguanidine, and the like.
As the sulfenamides, N-cyclohexyl-2-benzothiazolylsulfenamide, N-oxydiethylene-2-benzthiazolylsulfenamide, N-tert-butyl-2-benzothiazolylsulfenamide or N, N′-dicyclohexyl-2-benzothiazolylsulfenamide and the like can be mentioned.

  The blending amount of the vulcanization accelerator may be an amount that sufficiently exhibits the physical properties of the rubber component. Usually, in the case of an inorganic accelerator, it is selected from a range of 0 to 15 parts by mass with respect to 100 parts by mass of the rubber component, and in the case of an organic accelerator, a range of 0.5 to 3 parts by mass with respect to 100 parts by mass of the rubber component. Is preferably selected from.

Examples of the vulcanization accelerator include metal oxides such as zinc oxide; fatty acids such as stearic acid, oleic acid, and cottonseed fatty acid; and other conventionally known vulcanization accelerators. In addition, metal oxides, such as zinc oxide, also play a role as the following reinforcing agent.
The blending amount of the vulcanization accelerator may be an amount that can sufficiently exhibit the physical properties of the rubber component, and is usually 0.5 to 20 parts by mass, preferably 1 to 15 parts by mass with respect to 100 parts by mass of the rubber component. Is selected from the range.

Examples of the antiaging agent include amines, phenols, imidazoles, phosphorus and thioureas.
Examples of amines include phenyl-α-naphthylamine, 2,2,4-trimethyl-1,2-dihydroquinoline polymer (TMDQ), 6-ethoxy-2,2,4-trimethyl-1,2-dihydroquinoline (ETMDQ). ), P, p′-dioctyldiphenylamine (ODPA), p, p′-dicumyldiphenylamine (DCDP), N, N′-di-2-naphthyl-p-phenylenediamine (DNPD), N, N′-diphenyl -P-phenylenediamine (DPPD), N-phenyl-N'-isopropyl-p-phenylenediamine (IPPD), N-phenyl-N'-1,3-dimethylbutyl-p-phenylenediamine (6PPD) and the like. It is done.
Phenols include 2,6-di-tert-butyl-4-methylphenol (BHT or DTBMP), styrenated methylphenol, 2,2′-methylenebis (4-methyl-6-tert-butylphenol) (MBMBP) 2,2′-methylenebis (4-ethyl-6-tert-butylphenol), 4,4′-thiobis (3-methyl-6-tert-butylphenol) (TBMTBP), 4,4′-butylidenebis (3-methyl) -6-tert-butylphenol) (BBMTBP), 2,5-di-tert-butylhydroquinone (DBHQ), 2,5-di-tert-amylhydroquinone (DAHQ) and the like.
Examples of imidazoles include 2-mercaptobenzimidazole (MBI), zinc salt of 2-mercaptobenzimidazole (ZnMBI), nickel dibutyldithiocarbamate (NiBDC), and the like.
Other examples include phosphorus such as tris (nonylated phenyl) phosphite, thiourea such as 1,3-bis (diaminopropyl) -2-thiourea or tributylthiourea, and a wax for preventing ozone deterioration.
In the present invention, p, p′-dicumyldiphenylamine and 2-mercaptobenzimidazole are preferably used.

The blending amount of the anti-aging agent may be an amount that sufficiently exhibits the physical properties of the rubber component, and two or more types may be combined. Usually, it is preferable that it is 0.1-15 mass parts with respect to 100 mass parts of rubber components (1). The blending amount of the anti-aging agent with respect to 100 parts by weight of the rubber component (1) is 0.1 to 15 parts by weight. When the blending amount is less than 0.1 parts by weight, the effect of preventing aging is exhibited. This is because there is a possibility that the mechanical properties are deteriorated and the wear may progress violently. If the blending amount exceeds 15 parts by mass, the dispersion may be poor due to excessive blending, and the mechanical properties may be degraded. Because there is. Preferably, the blending amount of the anti-aging agent with respect to 100 parts by mass of the rubber component (1) is 0.5 part by mass to 10 parts by mass, and particularly 3 parts by mass is preferable.

Specific examples of the rubber softener include phthalic acid derivatives, isophthalic acid derivatives, adipic acid derivatives, sebacic acid derivatives, benzoic acid derivatives, and phosphoric acid derivatives.
More specifically, dibutyl phthalate (DBP), di- (2-ethylhexyl) phthalate, dioctyl phthalate (DOP), diisooctyl phthalate (DIOP), higher alcohol-phthalate, di- (2-ethylhexyl) sebacate, adipine Acid polyester, dibutyl diglycol-adipate, di (butoxyethoxyethyl) adipate, isooctyl-tol oil fatty acid ester, tributyl phosphate (TBP), tributoxyethyl phosphate (TBEP), tricresyl phosphate (TCP), cresyl-di Examples include phenyl phosphate (CDP) and diphenylalkane.
The amount of the softening agent is not particularly limited as long as the physical properties of the rubber component are sufficiently exhibited, and are usually selected from the range of 0.5 to 5 parts by mass with respect to 100 parts by mass of the rubber component.

As the reinforcing agent, carbon black is mainly used as a filler that induces interaction with rubber, and, for example, white carbon (for example, silica-based filler such as dry silica or wet silica, silicate such as magnesium silicate) Etc.), calcium carbonate, magnesium carbonate, magnesium silicate, clay (aluminum silicate), silane-modified clay or talc and other inorganic reinforcing agents, coumarone indene resin, phenol resin, high styrene resin, wood powder and other organic Reinforcing agents can be used.
Among these, carbon black is preferably used from the viewpoints of the reinforcing effect, cost, dispersibility, and wear resistance. Examples of the carbon black include SAF carbon (average particle diameter of 18 to 22 nm), SAF-HS carbon (average particle diameter of about 20 nm), ISAF carbon (average particle diameter of 19 to 29 nm), and N-339 carbon (average particle diameter of 24 nm). Before and after), ISAF-LS carbon (average particle size 21-24 nm), I-ISAF-HS carbon (average particle size 21-31 nm), HAF carbon (average particle size 26-30 nm), HAF-HS carbon (average particle size) 22-30 nm), N-351 carbon (average particle size around 29 nm), HAF-LS carbon (average particle size 25-29 nm), LI-HAF carbon (average particle size around 29 nm), MAF carbon (average particle size 30- 35 nm), FEF carbon (average particle size 40-52 nm), SRF carbon (average particle size 58-94 nm) SRF-LM carbon, GPF carbon (average particle diameter 49～84Nm) and the like. Among these, it is preferable to use FEF carbon, ISAF carbon, SAF carbon, or HAF carbon.
The amount of the reinforcing agent to be blended may be an amount that sufficiently exhibits the physical properties of the rubber component, and is usually selected from the range of 5 to 100 parts by mass with respect to 100 parts by mass of the rubber component.

Examples of the additive include amide compounds, fatty acid metal salts, and waxes.
Examples of the amide compound include aliphatic amide compounds and aromatic amide compounds. In particular, aliphatic amide compounds include oleic acid, stearic acid, erucic acid, caproic acid, caprylic acid, capric acid, lauric acid, myristic acid, palmitic acid, arachidic acid, hebenic acid, palmitoleic acid, eicosenoic acid, erucin Examples include acids, elaidic acid, trans-11-eicosenoic acid, trans-13-docosenoic acid, linoleic acid, linolenic acid, or ricinoleic acid amides, and one type can be used alone or two or more types can be used in combination. Also good. Of these, oleic acid amide, stearic acid amide, and erucic acid amide are preferably used.
As the fatty acid metal salt, a fatty acid selected from lauric acid, stearic acid, palmitic acid, myristic acid and oleic acid, zinc, iron, calcium, aluminum, lithium, magnesium, strontium, barium, cerium, titanium, zirconium, Examples thereof include a salt composed of a metal selected from lead and manganese.
Examples of the wax include paraffin, montan, and amide.

  The compounding amount of the additive is not particularly limited as long as the physical properties of the rubber component are sufficiently exhibited, and is usually selected from the range of 1 to 10 parts by mass with respect to 100 parts by mass of the rubber component.

Thermosetting elastomer composition composing the cleaning blanking rate of the present invention, as the crosslinking agent (3), sulfur, organic sulfur compounds, organic peroxides, organic peroxides among the heat-resistant crosslinking agent and a resin crosslinking agent Used.
The cross-linking agent (3) preferably are formulated in 0.1 to 30 parts by mass of the rubber component (1) 100 parts by weight. This is because there is a possibility that the amount of cross-linking agent (3) can not be obtained the desired properties is the vulcanization density becomes small at less than 0.1 part by weight, whereas, cross-linking agent (3) If the amount exceeds 30 parts by mass, the hardness becomes too large due to an excessive vulcanization reaction, and the image forming apparatus cleaning blade of the present invention may damage the photoreceptor.
More specifically, the amount of the organic peroxide is preferably from 0.5 to 10 parts by mass with respect to 100 parts by mass of the rubber component, not more preferable to be 1 to 6 parts by weight.

The organic peroxide, benzoyl peroxide, 1,1-di - (tert-butylperoxy) -3,3,5-trimethylcyclohexane, 2,5-dimethyl-2,5-di - (Benzoirupa Oxy) hexane, 2,5-dimethyl-2,5-di- (benzoylperoxy) -3-hexyne, 2,5-dimethyl-2,5-di- (tert-butylperoxy) hexane, di-tert -Butylperoxydiisopropylbenzene, di-tert-butyl peroxide, di-tert-butylperoxybenzoate, dicumyl peroxide, tert-butylcumyl peroxide, 2,5-dimethyl-2,5-di- (tert -Butylperoxy) -3-hexyne, 1,3-bis (tert-butylperoxyisopropyl) benzene, n- Examples include til-4,4-bis (tert-butylperoxy) valerate, p-chlorobenzoyl peroxide, 2,4-dichlorobenzoyl peroxide, tert-butylperoxyisopropyl carbonate, diacetyl peroxide, lauroyl peroxide, and the like. It is done.
In the present invention, dicumyl peroxide is preferably used.

The thermosetting elastomer composition constituting the cleaning blade for an image forming apparatus of the present invention is a thermosetting elastomer containing a rubber component (1), a filler (2), a crosslinking agent (3) and a dispersion improver (4). The composition is any one of the following (I) or (II) .
(I) As a filler (2), a zinc methacrylate is included.
(II) As rubber component (1), HNBR contains zinc methacrylate .

In any embodiment, zinc methacrylate acts as a co-crosslinking agent, undergoes a polymerization / grafting reaction during crosslinking to form a fine structure, and provides higher mechanical properties than ordinary carbon black reinforcement, and wear resistance. Can be improved. Further, the dispersion improver (4) has a function of appropriately stopping the chain reaction by zinc methacrylate , and by this termination reaction, the polymerization / grafting reaction by zinc methacrylate is uniformly performed, and the edge wear is made uniform, The cleaning performance can be improved.

Deletion “The α, β-unsaturated carboxylic acid metal salts of (I) and (II) include those such as acrylic acid, methacrylic acid, maleic acid, fumaric acid, etc. Examples thereof include a sodium salt, an aluminum salt, a calcium salt, a zinc salt, or a magnesium salt of a saturated carboxylic acid, preferably zinc methacrylate.

The thermosetting elastomer composition of the aspect (I) will be described in detail below.
Instead of blending zinc methacrylate, a mixture of methacrylic acid and zinc oxide may be blended. When the mixture is blended, zinc methacrylate is formed in the rubber composition and functions as a co-crosslinking agent. Thus, zinc oxide blended with methacrylic acid for the purpose of producing zinc methacrylate is included in the co-crosslinking agent and not included in the vulcanization accelerator.
The mixing ratio of methacrylic acid and zinc oxide in the mixture is preferably 2: 1. However, usually because sometimes methacrylic Le acid does not react with all of the zinc oxide to 2: 1, preferably 1: you mixed 1.

The amount of zinc methacrylate or a mixture of methacrylic acid and zinc oxide is preferably a ratio of 5 parts to 60 parts by mass with respect to 100 parts by mass of the rubber component.
If the blending amount of zinc methacrylate or a mixture of methacrylic acid and zinc oxide is less than 5 parts by mass, the co-crosslinking effect of zinc methacrylate may not be exhibited, and mechanical properties may deteriorate and wear may progress. On the other hand, if it exceeds 60 parts by mass, it may be impossible to knead with a rubber kneader due to excessive blending. Preferably, the amount of the mixture of zinc oxide and zinc methacrylate or methacrylic acid is 5 parts by mass to 50 parts by mass with respect to 100 parts by mass of the rubber component.

In this embodiment (I), the rubber component (1), the crosslinking agent (3) and the dispersion improver (4) are the same as described above. Further, as the filler (2), in addition to a mixture of zinc oxide and zinc methacrylate or methacrylic acid may further contain other fillers described above.

The thermosetting elastomer composition of the aspect (II) will be described in detail below.
To obtain those obtained by blending zinc methacrylate in the HNBR serving as the base polymer, may be finely dispersed was mixed with zinc methacrylate HNBR, mixed with zinc oxide and methacrylic acid in HNBR, by mixing The generated zinc methacrylate may be finely dispersed in HNBR. Furthermore, a commercially available product in which zinc methacrylate is mixed with HNBR in advance and finely dispersed can also be used.
HNBR, which is the base polymer, is preferably HNBR having a bound acrylonitrile amount of 21% to 46% and a Mooney viscosity ML1 + 4 (100 ° C.) of 20 to 160.

In this embodiment (II), HNBR rather than using only rubber which zinc methacrylate is dispersed as the rubber component (1), have use in combination with other rubber other than the rubber as the other rubber H NBR is used .

In this embodiment (II), 5 to 60 parts by weight content of the rubber component to the total mass 100 parts by mass of the zinc methacrylate, preferably such that the proportion of 5 to 50 parts by weight, the zinc methacrylate HNBR What is necessary is just to determine the compounding quantity of the zinc methacrylate in the disperse | distributed rubber | gum, and the mixing ratio of the said rubber | gum and another rubber | gum.
Especially, it is preferable to use the rubber | gum which mix | blended zinc methacrylate with 40 mass parts-240 mass parts with respect to 100 mass parts of HNBR, Preferably it is 80 mass parts-120 mass parts, Most preferably, 91 mass parts-115 mass parts. .
Further, it is preferable that the rubber compounded with methacrylic SanA lead in 91 parts by weight of 115 parts by mass, the rubber component to the total mass 100 parts by mass with respect to being blended 10-75 parts by weight with respect to HNBR100 parts by weight, 30 to More preferably, 60 parts by mass is blended.
Thus, 10 to 75 parts by mass of the rubber compounded with 91 parts by mass to 115 parts by mass of zinc methacrylate with respect to 100 parts by mass of HNBR with respect to 100 parts by mass of the total rubber component is compounded. When the amount is less than 10 parts by mass, the amount of zinc methacrylate with respect to 100 parts by mass of the total rubber component is less than 5 parts by mass, the co-crosslinking effect of zinc methacrylate is not exhibited, and mechanical properties are deteriorated or worn. It is because there is a possibility of proceeding. On the other hand, when the blending amount exceeds 75 parts by mass, the amount of zinc methacrylate with respect to 100 parts by mass of the total rubber component becomes more than 60 parts by mass, and the excessive amount of zinc methacrylate makes it impossible to knead with a rubber kneader. This is because there is a possibility that unreacted substances may be poorly dispersed or agglomerates to adversely affect the wear resistance.

In the present embodiment (II), the filler (2), the crosslinking agent (3) and the dispersion improver (4) are the same as described above.
However, since zinc methacrylate is blended in advance with the rubber component (1), it is not necessary to blend methacrylic acid or a mixture of methacrylic acid and zinc oxide as the filler (2).
In the present invention, as described above, a rubber component composed of a mixture of NBR or HNBR and zinc methacrylate, or a mixture of HNBR and HNBR finely dispersed in zinc methacrylate,
Benzenethiol, diphenyl disulfide, bis (pentabromophenyl) disulfide, 4-fluoro 0.05 one selected from thiophenol zinc salt or two of the dispersion-improving agent to 100 parts by mass of the rubber component 3 . An image forming apparatus comprising 0 part by mass, molded from a thermosetting elastomer composition vulcanized with a crosslinking agent comprising an organic peroxide, and having a tensile strength of 35 to 55 MPa measured according to JIS K 6251 It is used as a cleaning blade.
A mixture of HNBR (ZDMA-containing HNBR) in which 20 parts by mass of zinc methacrylate is blended with 100 parts by mass of NBR or HNBR, and HNBR and zinc methacrylate are finely dispersed is 45:55 in HNBR: ZDMA-containing HNBR. It is preferable to mix | blend with.
The organic peroxide is composed of dicumyl peroxide, is blended in an amount of 3 parts by mass with respect to 100 parts by mass of the rubber component, and further contains p, p'-dicumyldiphenylamine and 2-mercaptobenzimidazole as an anti-aging agent. 3 parts by mass is blended with 100 parts by mass of the rubber component.
The rebound resilience of the thermosetting elastomer composition configured as described above is 47 to 68%.

From the thermosetting elastomer composition containing the above components, the cleaning blade for an image forming apparatus of the present invention can be produced as follows.
First, the thermosetting elastomer composition is prepared by mixing the components using a kneading apparatus such as a single screw extruder, a 1.5 screw extruder, a twin screw extruder, an open roll, a kneader, a Banbury mixer, or a hot roll. Get. The mixing order of each component is not particularly limited, and all the components may be added to the kneader at once and mixed, or some of the components may be added to the kneader and kneaded in advance. The remaining components may be added to the mixture and kneaded. Preferably, a method of kneading the rubber component (1) and the filler (2) in advance, adding the crosslinking agent (3) and the dispersion improver (4) to the obtained mixture, and kneading is preferable.
The crosslinking of the kneaded product may be performed before or after the molding of the kneaded product, or may be performed simultaneously with the molding of the kneaded product in order to shorten the working time. In the case of producing the cleaning blade for an image forming apparatus of the present invention by performing crosslinking simultaneously with the molding of the kneaded product, the desired mold is heated, the heated mold is filled with the kneaded product, and the compression molding (pressing is performed. Obtained by vulcanization).

One embodiment of a cleaning blade for an image forming apparatus of the present invention is shown in FIG.
The cleaning blade 10 is usually joined to the support member 21 with an adhesive. The support member 21 is made of a rigid metal, an elastic metal, plastic or ceramic, but is preferably made of metal. Examples of the adhesive used for joining the cleaning blade 10 and the support member 21 include a polyamide-based or polyurethane-based hot melt adhesive, an epoxy-based or phenol-based adhesive, and the like. Among these, it is preferable to use a hot melt adhesive.
The cleaning blade 10 includes a surface 10a facing the member to be cleaned, a back surface 10c to which the support member 21 is bonded, and a thickness surface 10b orthogonal to both the front and back surfaces. The surface 10a and the thickness surface 10b The sandwiched edge portion 10d contacts the member to be cleaned to remove the toner.

The image forming apparatus cleaning blade of the present invention preferably has the following performance.
It is preferable that the rebound resilience of the thermosetting elastomer composition constituting the cleaning blade for an image forming apparatus of the present invention is 47 to 68 %. By using a material having a high impact resilience in this way, the wear resistance of the edge portion can be improved.
The rebound resilience is measured at a temperature of 23 ° C. according to the JIS K 6255 Lupke method using compressed balls produced by the same method as the cleaning blade of the present invention.

The tensile strength of the thermosetting elastomer composition constituting the cleaning blade for an image forming apparatus of the present invention is 35 to 55 MPa . This is because if the tensile strength is less than 35 MPa, the cleaning blade becomes brittle and wear may be severe.
The tensile strength is prepared by punching out a dumbbell-shaped No. 3 test piece from a 2 mm-thick sheet prepared by the same method as the cleaning blade of the present invention, and the tensile strength is measured at a tensile strength of 500 mm / min according to JIS K 6251.

The cleaning blade for an image forming apparatus of the present invention preferably has a wear index value of 40 μm or less after a paper passing test performed by being mounted on the image forming apparatus. The wear index value is more preferably 30 μm or less, and the lower limit is preferably as close to 0 as possible, but is 1 μm or more.
This is because the fact that the cross-sectional length of the worn surface is smaller than 1 μm means that the thermosetting elastomer is not worn, and this is an area that is practically impossible. Further, the upper limit is set to 40 μm or less because when it exceeds 40 μm, the edge is worn out violently and cleaning failure may occur.

The cleaning blade for an image forming apparatus of the present invention preferably has a cleaning performance value of 0.5 or less after a paper passing test performed by being mounted on the image forming apparatus. The cleaning performance value is more preferably 0.4 or less.
A cleaning performance value of 0 means that all toner has been cleaned, indicating the best cleaning performance. The reason why the cleaning performance value is 0.5 or less is that if it exceeds 0.5, the amount of toner passing through increases, which may adversely affect the printed image.

The wear index value and the cleaning performance value after the paper passing test performed by mounting on the image forming apparatus are measured and evaluated in the following manner.
First, a paper passing test is performed. Specifically, a cleaning blade punched out from a 2 mm thick sheet made of a thermosetting elastomer composition into a blade-like size is adhered to and supported on a support, and the image is displayed while the cleaning blade is in contact with the photoreceptor. Attach to the forming device. The image forming apparatus is a printer capable of developing toner by rotating a photoreceptor. As the toner, a sphere polymerization toner having a volume average particle diameter of 5 to 10 μm and a sphericity of 0.90 to 0.99 is used. Printing is performed on 150,000 sheets at a printing density of 4% under the conditions of a temperature of 23 ° C. and a relative humidity of 55% at a rotational speed of the photosensitive member of 200 to 500 mm / second.

When the edge of the cleaning blade after the paper passing test is observed, the edge portion is worn as shown in the cross-sectional view of FIG. The shaded part is the worn part of the blade. In the cross-sectional view of FIG. 2A, the wear surface is a straight line, but a curved line may be drawn.
The cross-sectional length Ws (23d in the figure) of the wear surface is a wear end of the wear length Wm (23a in the figure) which is the wear length on the surface 10a of the cleaning blade, that is, the wear length in the depth direction, This is the length of the inclined surface when the wear end of the thickness 10b of the cleaning blade, that is, the wear end of the wear width Wc (23b in the figure), which is the wear length in the longitudinal direction, is connected in a straight line. The wear index value is measured as a horizontal distance when the cross-sectional length Ws of the wear surface is inclined at 45 degrees. Specifically, the cleaning blade taken out from the image forming apparatus after the paper passing test is in an upright state as shown in FIG. 1, that is, the surface 10a of the cleaning blade is upward from the state in which the thickness surface 10b is parallel to the ground. Tilt 45 ° so that An enlarged cross-sectional view of the tip portion of the cleaning blade in this state is the cross-sectional view of FIG. The horizontal distance (24 in the figure) of the cross-sectional length Ws (23d in the figure) is the wear index value.

  After the paper passing test, the toner amount per unit area on the photoconductor is calculated in advance, and is set as the toner amount Ta before passing through. Next, the photosensitive member is rotated and the toner is cleaned with a cleaning blade. Thereafter, the amount of toner present on the photoreceptor behind the cleaning blade is converted into a unit area, and is set as a toner amount Tb after slipping. The ratio of the toner amount Tb after slipping to the toner amount Ta before slipping (Tb / Ta) is the cleaning performance value.

  The wear resistance of the edge portion is improved by improving the resilience of the thermosetting elastomer constituting the cleaning blade for the image forming apparatus. When the wear resistance of the edge portion is improved, the contact pressure with the member to be cleaned such as the photosensitive member can be set high, and the cleaning performance is improved. The present invention is characterized by utilizing the relationship between such a resilience modulus, wear resistance, linear pressure, and thus cleaning performance. And as the specific means, the dispersibility of a filler (2) is improved especially by mix | blending the thiol or / and sulfide which has a specific chemical structure as a dispersion improver (4), and a thermosetting elastomer composition Improves the impact resilience of the object. As a result, it is possible to provide a cleaning blade for an image forming apparatus having excellent wear resistance and cleaning performance.

  Further, when fluorine-substituted benzene thiol or / and a metal salt thereof is used as the dispersion improver (4), the same effect as that of blending the thiol or / and sulfide can be obtained. In addition, since the cleaning blade can have a high impact resilience while having a low hardness, it is possible to provide a cleaning blade for an image forming apparatus having excellent wear resistance and cleaning performance.

As shown in FIG. 1, the cleaning blade 10 for an image forming apparatus of the present invention is joined to a support member 21 made of metal, preferably made of chromium-free SECC, using a hot melt adhesive.
The cleaning blade 10 for an image forming apparatus of the present invention is incorporated in the image forming apparatus with a structure as shown in FIG. 3, for example. Then, the toner remaining on the surface of the photosensitive drum is removed by contacting the photosensitive drum. More specifically, an image is formed by the following mechanism, and the toner remaining on the surface of the photosensitive drum is removed by the cleaning blade for an image forming apparatus of the present invention.

First, after the photosensitive member 12 is rotated in the direction of the arrow in the drawing and the photosensitive member 12 is charged by the charging roller 11, the laser 17 exposes the non-image portion of the photosensitive member 12 through the mirror 16 to remove static electricity. The portion corresponding to the image line portion is charged. Next, the toner 15a is supplied onto the photoreceptor 12, and the toner 15a adheres to the charged image line portion to form a first color image. This toner image is transferred onto the intermediate transfer belt 13 via the primary transfer roller 19a. Similarly, each color image of the toners 15b to 15d formed on the photoconductor 12 is transferred onto the intermediate transfer belt 13, and a full color image composed of the four color toners 15 (15a to 15d) is formed on the transfer belt 13. Once formed. The full-color image is transferred onto a transfer target (usually paper) 18 via a secondary transfer roller 19b, and fixed on the surface of the transfer target 18 by passing through a fixing roller 14 heated to a predetermined temperature. Is done.
In this process, the toner remaining on the photosensitive member 12 without being transferred onto the intermediate transfer belt 13 is exposed to the cleaning blade 20 pressed against the surface of the photosensitive member 12 in order to sequentially copy on a plurality of recording sheets. It is removed by rubbing the body 12 and collected in the toner collection box 22.

The image forming apparatus cleaning blade 10 of the first embodiment of the present invention is molded from a thermosetting elastomer composition comprising the following components.
As the rubber component (1), NBR or HNBR is used.
As NBR, it is preferable to use medium-high nitrile NBR having a bound acrylonitrile amount of 31% to 35%.
As HNBR, a medium-high nitrile NBR hydrogenated to have a residual double bond of 10% or less is preferable.

As the filler (2), a co-crosslinking agent and an anti-aging agent are used.
As a co-crosslinking agent, methacrylic acid and zinc oxide are blended.
These are blended so that the sum of the blending amount of methacrylic acid and the blending amount of zinc oxide is 5 to 40 parts by mass, preferably 10 to 30 parts by mass with respect to 100 parts by mass of the rubber component (1). .
The mixing ratio (mass) of methacrylic acid and zinc oxide is preferably 1 to 2: 1 and more preferably 1: 1.

As the anti-aging agent, it is preferable to use amines and imidazoles, and it is more preferable to use p, p′-dicumyldiphenylamine and 2-mercaptobenzimidazole in combination.
The blending amount of the antioxidant is preferably 0.1 to 10 parts by mass, more preferably 0.5 to 5 parts by mass with respect to 100 parts by mass of the rubber component.

An organic peroxide is used as the crosslinking agent (3). Of these, dicumyl peroxide is preferably used.
The compounding amount of the organic peroxide is preferably 0.5 to 10 parts by mass, more preferably 1 to 6 parts by mass with respect to 100 parts by mass of the rubber component.

As the dispersion improver (4), a thiol represented by the chemical formula (1) or a sulfide represented by the chemical formula (2) is used.
Benzenethiol is used as the thiol represented by the chemical formula (1).
As the sulfide represented by the chemical formula (2), diphenyl disulfide or bis (pentabromophenyl) disulfide is used.
These may be used individually by 1 type and may be used in combination of 2 or more types.

Dispersion-improving agent (4) is 100 parts by mass of the rubber component to be blended in a proportion of 0.05 3 parts by weight. More specifically, the thiol represented by the chemical formula (1) preferably are blended at a ratio of 0.1 to 1 3 parts by mass with respect to 100 parts by mass of the rubber component. The sulfide represented by the chemical formula (2) is preferably blended at a ratio of 0.05 to 10 parts by mass with respect to 100 parts by mass of the rubber component. If used in combination sulfide represented by thiols and formula represented by the chemical formula (1) (2), that the mixture is blended at a ratio of 0.1 to 1 3 parts by mass with respect to 100 parts by mass of the rubber component.

The image forming apparatus cleaning blade 10 of the second embodiment of the present invention is molded from a thermosetting elastomer composition comprising the following components.
As the rubber component (1), rubber in which zinc methacrylate is finely dispersed in HNBR as a base polymer is used.
The amount of zinc methacrylate dispersed in HNBR as the base polymer is preferably 91 parts by mass to 110 parts by mass with respect to 100 parts by mass of HNBR.
The base polymer HNBR preferably has a bound acrylonitrile amount of 21% to 44% and a Mooney viscosity ML1 + 4 (100 ° C.) of 40 to 150.

In the present embodiment, it is preferable to use a combination of the rubber obtained by finely dispersing zinc methacrylate in HNBR and another rubber. Other rubber is preferably NBR and / or HNBR, more preferably HNBR.
When used in combination with other rubbers, the blending amount of rubber in which zinc methacrylate is finely dispersed in HNBR is 30 to 60 parts by mass, preferably 40 to 100 parts by mass of the total mass of the rubber component (1). Adjust to 60 parts by mass.

An anti-aging agent is used as the filler (2). The antiaging agent is the same as in the first embodiment.
The crosslinking agent (3) and the dispersion improver (4) are the same as in the first embodiment.

The image forming apparatus cleaning blade 10 according to the third embodiment of the present invention is molded from the thermosetting elastomer composition in which the type and amount of the dispersion improver (4) are changed. Specifically, as the dispersion improver (4), fluorine-substituted benzenethiol represented by the chemical formula (3) or / and a metal salt thereof is used, and the dispersion improver (4) is added to 100 parts by mass of the rubber component (1). On the other hand, it mix | blends in the ratio of 0.05-10 mass parts. The dispersion-improving agent (4), Iteiru use the fluorothiophenol zinc salt.
The fluorine-substituted benzenethiol represented by the chemical formula (3) may be combined with the thiol represented by the chemical formula (1) and / or the sulfide represented by the chemical formula (2). In this case, the dispersion improver (4) The total compounding amount is set to 0.05 to 10 parts by mass with respect to 100 parts by mass of the rubber component (1).
Other components and blending amounts are the same as in the first embodiment.

A cleaning blade 10 for an image forming apparatus according to a fourth embodiment of the present invention is molded from the thermosetting elastomer composition in which the type and the blending amount of the dispersion improver (4) are changed. As the dispersion improver (4) of this embodiment, the same amount of the same kind of dispersion improver as that of the third embodiment is used.
Other components and blending amounts are the same as in the first embodiment.

The image forming apparatus cleaning blade 10 according to the first embodiment to the fourth embodiment of the present invention can be manufactured as follows, for example.
First, the rubber component (1) and the filler (2) are kneaded using a kneading apparatus such as a single screw extruder, a 1.5 screw extruder, a twin screw extruder, an open roll, a kneader, a Banbury mixer, or a hot roll. The kneading temperature is 80 ° C. to 120 ° C., and the kneading time is 5 to 6 minutes. If the kneading temperature is less than 80 ° C. and the kneading time is less than 5 minutes, the rubber component (1) is not sufficiently plasticized and kneading tends to be insufficient. The kneading temperature exceeds 120 ° C. and the kneading time is 6 minutes. It is because there exists a possibility that a rubber component (1) may decompose | disassemble exceeding it.
Next, the crosslinking agent (3) and the dispersion improver (4) are added to the obtained mixture and kneaded using the kneading apparatus as described above. The kneading temperature is 80 ° C. to 90 ° C., and the kneading time is 5 minutes to 6 minutes. This is because if the kneading temperature is less than 80 ° C. and the kneading time is less than 5 minutes, the mixture is not sufficiently plasticized and kneading tends to be insufficient. If the kneading temperature exceeds 90 ° C. and the kneading time exceeds 6 minutes, This is because the crosslinking agent (3) may be decomposed.

The cleaning blade 10 of the present invention is molded from the thermosetting elastomer composition obtained as described above. The cleaning blade 10 is preferably formed and processed into a strip shape having a thickness of 1 mm to 3 mm, a width of 10 mm to 40 mm, and a length of 200 mm to 500 mm.
It does not specifically limit as a shaping | molding method, What is necessary is just to use well-known shaping | molding methods, such as injection molding and compression molding. Specifically, for example, a method in which a thermosetting elastomer composition is set in a mold and press vulcanized at 160 to 170 ° C. for 20 to 40 minutes can be mentioned. This is because when the vulcanization temperature is less than 160 ° C. and the vulcanization time is less than 20 minutes, vulcanization is insufficient. When the vulcanization temperature exceeds 170 ° C. and the vulcanization time exceeds 40 minutes, the rubber component (1) is This is because there is a risk of decomposition.

The thus obtained cleaning blade 10 for an image forming apparatus of the present invention preferably has a wear index value of 40 μm or less after a paper passing test performed by being mounted on the image forming apparatus, and preferably 25 to 40 μm. More preferred. In addition, the cleaning performance value after a paper passing test performed on the image forming apparatus is preferably 0.5 or less, and more preferably 0.35 to 0.5.
Furthermore, it is preferable that the rebound resilience of the thermosetting elastomer composition constituting the cleaning blade for an image forming apparatus of the present invention is 47 to 68 %. Moreover, it is preferable that the tensile strength of the said thermosetting elastomer composition shows 35-55 MPa.

EXAMPLES The present invention will be described below with reference to examples, but the present invention is not limited to the following examples.
(Examples 1-20, Comparative Examples 1-13)
The rubber component (1) and the filler (2) are weighed in the following table (unit: parts by mass) and charged into a rubber kneading apparatus such as a twin screw extruder, open roll, Banbury mixer or kneader. The mixture was kneaded for 5 to 6 minutes while heating to 120 ° C.
The obtained mixture, the crosslinking agent (3) and the dispersion improver (4) in the blending amounts (units are parts by mass) shown in the following table are put into a rubber kneading apparatus such as an open roll, a Banbury mixer or a kneader, and 80 to It knead | mixed for about 5 to 6 minutes, heating at 90 degreeC.
The obtained thermosetting elastomer composition was set in a mold and press vulcanized at 160 ° C. for about 30 minutes to produce a 2 mm thick sheet and a compressed ball of φ27.5 mm × 12 mm thick.
Further, a cleaning blade having a width of 27 mm and a length of 320 mm is cut out from a sheet having a thickness of 2 mm, the cleaning blade is attached to a chrome-free SECC support member using hot melt, and the center portion of the sheet is cut to produce a cleaning member. did.

The following products were specifically used for the components listed in the above table.
NBR: “N232S” manufactured by JSR Corporation (bound acrylonitrile content 35%)
・ HNBR: “Zetpol 2010H” manufactured by Nippon Zeon Co., Ltd. (bound acrylonitrile amount 36%, Mooney viscosity 145)
-ZDMA-containing HNBR; "Zeoforte ZSC 2195H" manufactured by Nippon Zeon Co., Ltd.
100 parts by mass of zinc methacrylate (ZDMA) finely dispersed in 100 parts by mass of HNBR (36% of bound acrylonitrile, Mooney viscosity 145) as a base polymer; methacrylic acid; “MAA (trade name) manufactured by Mitsubishi Rayon Co., Ltd. )
・ Zinc oxide; “Zinc oxide 2 types (trade name)” manufactured by Mitsui Kinzoku Co., Ltd.
Anti-aging agent A; p, p′-dicumyldiphenylamine (“NOCRACK CD” manufactured by Ouchi Shinsei Chemical Co., Ltd.)
Anti-aging agent B; 2-mercaptobenzimidazole (“NOCRACK MB” manufactured by Ouchi Shinsei Chemical Co., Ltd.)
Organic peroxide: Dicumyl peroxide (Nippon Yushi Co., Ltd. “Park Mill D”)
・ Dispersion improver A: benzenethiol (manufactured by Sumitomo Seika Co., Ltd.)
-Dispersion improver B: diphenyl disulfide (manufactured by Sumitomo Seika Co., Ltd.)
-Dispersion improver C: bis (pentabromophenyl) disulfide-Dispersion improver D: 4-fluorothiophenol zinc salt

The physical properties described in the above table were measured by the following methods.
(1) Rebound resilience The rebound resilience at a temperature of 23 ° C. was measured by the JIS K 6255 Rupke method using the produced compression balls.
(2) Tensile strength A dumbbell-shaped No. 3 test piece was punched out from the prepared 2 mm-thick sheet, and the tensile strength was measured at a tensile speed of 500 mm / min in accordance with JIS K 6251.

(3) Evaluation of wear resistance The cleaning members produced in the examples and comparative examples were mounted on an image forming apparatus. The image forming apparatus is a commercially available printer capable of forming an image by rotating a photoreceptor. The photoconductor was rotated at a rotational speed of 200 to 500 mm / second, printing 150,000 sheets at a 4% print density, and the edge of the cleaning blade after printing was observed.
As shown in FIG. 2, the wear resistance evaluation is an inclined surface obtained by connecting a wear end having a wear depth Wm (23 a in the figure) and a wear end having a wear width Wc (23 b in the figure) with a straight line. The cross-sectional length Ws (symbol 23d), which is the length of, was measured as the horizontal distance (symbol 24) at an inclination of 45 degrees, and the obtained value was used as a wear index value to evaluate the wear resistance based on the magnitude.
This test was conducted at a room temperature of 23 ° C. and a relative humidity of 55%.

(4) Evaluation of cleaning performance The cleaning members prepared in Examples and Comparative Examples were mounted on an image forming apparatus (manufactured in-house) capable of developing toner by rotating the photoreceptor. As the toner, a true sphere polymerization toner having a volume average particle diameter of 5 to 10 μm and a sphericity of 0.90 to 0.99 was used.
150,000 sheets of 4% printed images were printed on the condition that the rotational speed of the photosensitive member was 200 to 500 mm / second. Next, the toner amount per unit area (toner amount Ta before slipping) on the photoconductor was calculated in advance, and the photoconductor was rotated and the cleaning blade cleaned the toner. Thereafter, the amount of toner present on the photoreceptor behind the cleaning blade was converted per unit area to obtain a slipping toner amount Tb. A cleaning performance value was calculated from these values based on the following formula.
Cleaning performance value = through toner amount Tb / pre-through toner amount Ta
This test was conducted at a room temperature of 23 ° C. and a relative humidity of 55%.

In Comparative Examples 1, 2, 6, 9, 10, and 11 in which no dispersion improver was blended and in Comparative Examples 3, 4, 7, and 12 in which only a small amount of dispersion improver was blended, abrasion resistance and cleaning The performance was also very inferior. Specifically, in the abrasion resistance evaluation, compared to the same example as the composition other than the dispersion improver, the amount of wear is observed at least 1.4 times, on average about 2 times, and more when 3 times. It was. Moreover, in cleaning performance evaluation, all showed 0.8 or more, and it turns out that the cleaning function is not fully demonstrated.
In Comparative Example 5 and Comparative Example 8 containing a large amount of the dispersion improver, although the cleaning performance is generally improved as compared with Comparative Examples 1 to 4 and Comparative Examples 6 and 7, it does not reach the practical level. It was also inferior in wear resistance. Further, in Comparative Example 13 where 13 parts by mass of the dispersion improver D was blended with respect to 100 parts by mass of the rubber component, it was found that the cleaning performance value exceeded 1.0 and the abrasion resistance was inferior.
On the other hand, it can be seen that Examples 1 to 20 sufficiently satisfy the practical level with a wear index value of 40 μm or less and a cleaning performance value of less than 0.5, and are excellent in wear resistance and cleaning performance.

It is a cross-sectional schematic diagram of a cleaning member having a cleaning blade for an image forming apparatus of the present invention. It is a figure for demonstrating the measuring method of a wear index value. (A) is an enlarged view of the edge part of the cleaning blade for an image forming apparatus after a paper passing test performed by being mounted on the image forming apparatus, and (B) is a diagram showing a measurement position of the wear index value. 1 is a schematic diagram of a color image forming apparatus equipped with a cleaning blade for an image forming apparatus of the present invention.

DESCRIPTION OF SYMBOLS 10 Cleaning blade 11 for image forming apparatuses Charging roller 12 Photoconductor 13 Intermediate transfer belt 14 Fixing roller 15 Toner 16 Mirror 17 Laser 18 Transfer object 19a, 19b Transfer roller 21 Support member 22 Toner collection box

Claims (4)

A rubber component composed of a mixture of NBR or HNBR mixed with zinc methacrylate, or a mixture of HNBR and HNBR finely dispersed in zinc methacrylate,
One or two dispersion improvers selected from benzenethiol, diphenyl disulfide, bis (pentabromophenyl) disulfide, and 4-fluorothiophenol zinc salt are added in an amount of 0.05 to 13.3 with respect to 100 parts by mass of the rubber component. An image forming apparatus comprising 0 part by mass, molded from a thermosetting elastomer composition vulcanized with a crosslinking agent comprising an organic peroxide, and having a tensile strength of 35 to 55 MPa measured according to JIS K 6251 Cleaning blade. 20 parts by mass of zinc methacrylate is blended with respect to 100 parts by mass of the NBR or HNBR,
2. The cleaning blade for an image forming apparatus according to claim 1, wherein the mixture of HNBR and HNBR (ZDMA-containing HNBR) in which zinc methacrylate is finely dispersed contains HNBR: ZDMA-containing HNBR at 45:55 . The organic peroxide is composed of dicumyl peroxide, and 3 parts by mass with respect to 100 parts by mass of the rubber component,
3. The image forming apparatus cleaning according to claim 1, wherein 3 parts by mass of p, p′-dicumyldiphenylamine and 2-mercaptobenzimidazole as anti-aging agents are blended with respect to 100 parts by mass of the rubber component. blade. The cleaning blade for an image forming apparatus according to any one of claims 1 to 3, wherein a rebound resilience of the thermosetting elastomer composition is 47 to 68% .

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