JP2014238436A - Intermediate transfer body and image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an intermediate transfer body that has an excellent contact property with a photoreceptor or a recording medium, and prevents the separation of a surface layer during image formation.SOLUTION: An intermediate transfer belt 10 has a base material 12, an elastic layer 14, and a surface layer 16 laminated in this order. The elastic layer 14 is composed of rubber material, and the surface layer 16 is composed of acrylic material. When the surface of the elastic layer 14 on the surface layer 16 side is measured by the FT-IR ATR method, a ratio of the peak intensity Ito the peak intensity Iin an infrared absorption spectrum (I/I) is 0.5 or more. Iis the peak intensity of the maximum absorption appearing at 2,950±50 cm, and Iis the peak intensity of the maximum absorption appearing at 3,400±50 cm.

Description

  The present invention relates to an intermediate transfer member and an image forming apparatus having the intermediate transfer member.

  In an image forming apparatus having an intermediate transfer member, a toner image formed on a photosensitive member is transferred to an intermediate transfer member and then transferred to a recording medium such as plain paper. An intermediate transfer belt is known as one form of the intermediate transfer member. The intermediate transfer belt has, for example, an elastic layer in order to improve contact with a photoreceptor or a recording medium, and has a surface layer on the elastic layer in order to improve durability (for example, scratch resistance). . As a method for producing a surface layer on an elastic layer, a method of depositing an inorganic component on the surface of the elastic layer by plasma CVD is known (see, for example, Patent Document 1).

International Publication No. 2010/103896

  The surface layer produced by the above method is too hard. For this reason, even if the elastic layer is deformed by its elasticity, the surface layer cannot be sufficiently deformed, and the contact property of the intermediate transfer belt may be insufficient. On the other hand, a surface layer made of an acrylic material does not have the above problem. However, the adhesive strength of the surface layer to the elastic layer may be insufficient. For this reason, the surface layer may be peeled off by stress applied to the intermediate transfer belt during image formation.

SUMMARY OF THE INVENTION An object of the present invention is to provide an intermediate transfer member that has excellent contact with a photoreceptor or a recording medium and prevents peeling of a surface layer during image formation.
Another object of the present invention is to provide an image forming apparatus having the above intermediate transfer member.

The intermediate transfer member according to the present invention is formed by overlapping an elastic layer made of a rubber material and a surface layer made of an acrylic material in this order, and satisfies the following formula. In the following formula, I ₃₄₅₀ is the peak intensity of the maximum absorption appearing at 3400 ± 50 cm ⁻¹ of the infrared absorption spectrum when the surface of the elastic layer is measured by the FT-IR ATR method, and I ₂₉₅₀ is It is the maximum absorption peak intensity appearing at 2950 ± 50 cm ⁻¹ of the infrared absorption spectrum when the surface of the elastic layer is measured by the FT-IR ATR method.
I ₃₄₅₀ / I ₂₉₅₀ ≧ 0.5

  The image forming apparatus according to the present invention includes at least the intermediate transfer member for transferring the toner image formed on the photosensitive member to a recording medium.

  In the present invention, sufficient hydroxyl groups appear on the surface of the elastic layer. For this reason, the surface layer comprised with the acryl-type material adhere | attaches an elastic layer with sufficient adhesive strength. Therefore, an intermediate transfer member is provided that has excellent contact with the photosensitive member or recording medium and prevents peeling of the surface layer during image formation. This intermediate transfer member can be used in an image forming apparatus as an intermediate transfer member having the above contact property and durability.

FIG. 1A is a diagram schematically showing an intermediate transfer member in one embodiment of the present invention, and FIG. 1B is a diagram schematically showing a layer structure of the intermediate transfer member shown in FIG. 1A. It is a figure for demonstrating the peak intensity in the peak intensity ratio prescribed | regulated by this invention. 1 is a diagram schematically illustrating a configuration of an image forming apparatus according to an embodiment of the present invention.

[Intermediate transfer member]
FIG. 1 shows an intermediate transfer belt as an embodiment of an intermediate transfer member according to the present invention. As shown in FIG. 1, the intermediate transfer belt 10 includes an endless belt-like base material 12, an elastic layer 14 made of a rubber material, and a surface layer 16 made of an acrylic material in this order. Constructed by overlapping.

  The base material 12 is an endless belt having desired conductivity and flexibility. The base material 12 is made of, for example, a flexible resin and supports the elastic layer 14. The substrate 12 is disposed because it is preferable from the viewpoint of improving the mechanical strength and durability of the intermediate transfer belt 10. The thickness of the base material 12 is, for example, 50 to 100 μm. Examples of the resin material of the substrate 12 include a heat resistant resin such as polyimide. The substrate 12 may be a cylindrical sleeve having conductivity. When a cylindrical sleeve is employed for the base member 12, an intermediate transfer drum which is another aspect of the intermediate transfer member is configured.

  The elastic layer 14 is a layer having desired conductivity and elasticity, which is formed on the outer peripheral surface of the substrate 12. The elastic layer 14 is made of a rubber material. The thickness of the elastic layer 14 is, for example, 50 to 500 μm. Examples of the rubber material include resins having rubber elasticity such as urethane rubber, chloroprene rubber (CR), and nitrile rubber (NBR). The rubber material preferably contains chloroprene rubber or nitrile butadiene rubber from the viewpoint of controlling the electric resistance of the intermediate transfer belt 10.

Both the base material 12 and the elastic layer 14 may further contain a conductive agent in order to develop the desired conductivity. As the conductive agent, a known material for imparting conductivity to the resin material of the intermediate transfer member is used. One or more conductive agents may be used. Examples of the conductive agent include an ionic conductive agent and an electronic conductive agent. Examples of ionic conductive agents include silver iodide, copper iodide, lithium perchlorate, lithium perchlorate, lithium perchlorate, lithium trifluoromethanesulfonate, lithium salts of organic boron complexes, lithium bisimide (( CF ₃ SO ₂ ) ₂ NLi) and lithium trismethide ((CF ₃ SO ₂ ) ₃ CLi). Examples of the electronic conductive agent include metals such as silver, copper, aluminum, magnesium, nickel, and stainless steel; and carbon compounds such as graphite, carbon black, and carbon nanofiber carbon nanotubes. The content of the conductive agent in the base material 12 and the elastic layer 14 is a total amount that realizes the desired volume resistivity of the intermediate transfer belt 10. The desired volume resistivity of the intermediate transfer belt 10 is, for example, 10 ¹² to 10 ⁸ Ω · cm.

  The surface layer 16 is a layer made of an acrylic material formed on the surface of the elastic layer 14. The surface layer 16 is a layer for protecting the surface of the elastic layer 14 and imparts sufficient durability against contact to the intermediate transfer belt 10. One or more acrylic materials may be used. Examples of the acrylic material include a polymer of an acrylic monomer, and a copolymer of an acrylic monomer and a monomer having an unsaturated bond copolymerizable with the acrylic monomer. The polymerization of the monomer can be performed by a known method such as heating or irradiation with active energy rays.

  Examples of the acrylic monomer include (meth) acrylic acid, (meth) acrylate, derivatives thereof, and polyfunctional (meth) acrylate. “(Meth) acrylic acid” is a general term for acrylic acid and methacrylic acid, and means one or both of acrylic acid and methacrylic acid. “(Meth) acrylate” is a general term for methacrylate and acrylate, and means one or both of methacrylate and acrylate. Examples of the monomer having an unsaturated bond include a vinyl copolymer. Examples of vinyl copolymers include vinyl acetate, styrene, acrylonitrile, and siloxane vinyl copolymers. The proportion of the structural unit derived from the acrylic monomer in the acrylic material is preferably 20% by mass or more from the viewpoint of sufficiently improving the adhesive strength of the surface layer. Although the upper limit of the said ratio is not specifically limited, For example, it can be 30 mass% from viewpoints, such as a degree of the improvement of the said effect, and economical efficiency. The thickness of the surface layer 16 is, for example, 1 to 7 μm.

  The surface layer 16 is a cured film of the paint containing the siloxane-based vinyl copolymer, the polyfunctional (meth) acrylate, and the metal oxide fine particles surface-treated with the surface treatment agent by irradiation with active energy rays. It is more preferable from the viewpoint of increasing the mechanical strength and durability of the surface layer 16.

  In the case where the surface layer 16 is the cured film, the Si concentration in the surface layer 16 having a depth of 2 to 5% with respect to the total thickness of the surface layer 16 from the surface of the surface layer 16 is 1 to 10%. From the viewpoint of further improving the filming resistance, transfer rate, and scratch resistance of the intermediate transfer member, it is preferably 4 to 10%. The Si concentration can be measured, for example, by depth profile measurement using argon ions in X-ray photoelectron spectroscopy (ESCA). Moreover, the Si concentration can be adjusted by, for example, the content of the siloxane-based vinyl copolymer in the paint.

  Furthermore, when the surface layer 16 is the above cured film, the content of the metal oxide fine particles in the surface layer 16 is preferably 10 to 100 parts by volume with respect to 100 parts by volume of the surface layer 16. If the content of the metal oxide fine particles is too small, the effect of increasing the mechanical strength of the surface layer may not be sufficiently obtained, and if it is too large, the surface layer may become brittle.

  A polyfunctional (meth) acrylate is preferable from the viewpoint of increasing the hardness of the surface layer. The polyfunctional (meth) acrylate has two or more (meth) acryloyloxy groups in one molecule. One or more polyfunctional (meth) acrylates may be used. Examples of the polyfunctional (meth) acrylate include bifunctional (meth) acrylate and trifunctional or higher polyfunctional (meth) acrylate. From the viewpoint of increasing the hardness of the surface layer, the polyfunctional (meth) acrylate is preferably a trifunctional or higher polyfunctional (meth) acrylate.

  Examples of bifunctional (meth) acrylates include bis (2-acryloxyethyl) -hydroxyethyl-isocyanurate, 1,6-hexanediol diacrylate, 1,4-butanediol diacrylate, 1,9-nonanediol Diacrylate, neopentyl glycol diacrylate, neopentyl glycol diacrylate hydroxypivalate and urethane acrylate are included.

  Examples of trifunctional or higher polyfunctional (meth) acrylates include trimethylolpropane triacrylate, pentaerythritol triacrylate, tris (acryloxyethyl) isocyanurate, ditrimethylolpropane tetraacrylate, pentaerythritol tetraacrylate, dipentaerythritol hexa Acrylate, urethane acrylate, and ester compound synthesized from polyhydric alcohol, polybasic acid and (meth) acrylic acid (for example, ester synthesized from trimethylolethane / succinic acid / acrylic acid = 2/1/4 mol) Compound).

  The siloxane-based vinyl copolymer contains one or more polyorganosiloxane chains A and three or more radical polymerizable double bonds to prevent filming in the intermediate transfer belt 10 and has a low surface layer. It is preferable from the viewpoint of maintaining the surface free energy. Such a siloxane-based vinyl copolymer includes, for example, a monomer (a) having a radical polymerizable double bond and a polyorganosiloxane chain A, and a radical polymerizable double bond and a reactive functional group. Reaction product of an intermediate copolymer obtained by radical polymerization of a monomer (b) having a functional group D capable of reacting with the reactive functional group and a compound (d) having a radical polymerizable double bond It has the structure of.

  The intermediate copolymer is a monomer (a), (b), a monomer other than the monomers (a) and (b) and having a radical polymerizable double bond ( A copolymer obtained by radical polymerization of c) may also be used. The “radical polymerizable double bond” is, for example, a carbon-carbon double bond in a vinyl group. The monomers (a) to (c) and the compound (d) may be one kind or more. Moreover, the number of radically polymerizable double bonds in each of the monomers (a) to (c) and the compound (d) may be one or more.

  The number of polyorganosiloxane chains A in the monomer (a) may be one or more. Examples of the monomer (a) include a one-terminal (meth) acryloxy group-containing polyorganosiloxane compound. Examples of commercially available monomers (a) include Silaplane FM-0711, FM-0721, FM-0725 manufactured by JNC Corporation; and X-22-174DX, X- manufactured by Shin-Etsu Chemical Co., Ltd. 22-2426, X-22-2475; The molecular weight of the polyorganosiloxane chain A is, for example, in a range where the weight average molecular weight of the monomer (a) is 1,000 to 10,000. “Silaplane” is a registered trademark of JNC Corporation.

  The copolymerization ratio of the monomer (a) in the intermediate copolymer is preferably 1 to 80% by mass, more preferably 5 to 5%, based on the total amount of monomers constituting the intermediate copolymer. It is 50 mass%, Most preferably, it is 10-45 mass%.

  The number of reactive functional groups possessed by the monomer (b) may be one or more. The reactive functional group is a functional group having reactivity to a functional group contained in an acrylic material, such as an ester bond and a group generated by hydrolysis thereof (for example, a hydroxyl group or a carboxyl group). Examples of the reactive functional group include a hydroxyl group, a carboxyl group, an isocyanate group, and an epoxy group.

  Examples of the monomer (b) having a hydroxyl group include 2-hydroxyethyl (meth) acrylate, 1-hydroxypropyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, Polyethylene glycol mono (meth) acrylate, polypropylene glycol mono (meth) acrylate, polytetramethylene glycol mono (meth) acrylate and hydroxystyrene are included.

  Examples of the monomer (b) having a carboxyl group include acrylic acid, methacrylic acid, crotonic acid, maleic acid, fumaric acid, itaconic acid and citraconic acid.

  Examples of the monomer (b) having an isocyanate group include (meth) acryloyloxyethyl isocyanate; (meth) acryloyloxypropyl isocyanate; and a reaction product of a hydroxyalkyl (meth) acrylate and a polyisocyanate. It is. Examples of “hydroxyalkyl (meth) acrylate” include 2-hydroxyethyl (meth) acrylate and 4-hydroxybutyl (meth) acrylate. Examples of “polyisocyanate” include toluene diisocyanate and isophorone diisocyanate.

  Examples of the monomer (b) having an epoxy group include glycidyl methacrylate, glycidyl cinnamate, glycidyl allyl ether, glycidyl vinyl ether, vinylcyclohexane monoepoxide and 1,3-butadiene monoepoxide.

  The copolymerization ratio of the monomer (b) in the intermediate copolymer is preferably 10 to 95% by mass, and 30 to 90% by mass with respect to the total amount of monomers constituting the intermediate copolymer. It is more preferable that it is 40-85 mass%.

  Examples of the monomer (c) include (meth) acrylic acid derivatives, aromatic vinyl monomers, olefinic hydrocarbon monomers, vinyl ester monomers, vinyl halide monomers and vinyl ether monomers. included.

  Examples of (meth) acrylic acid derivatives include alkyl (meth) acrylates such as (meth) acrylonitrile, methyl (meth) acrylate, butyl (meth) acrylate, ethylhexyl (meth) acrylate, stearyl (meth) acrylate; and benzyl (Meth) acrylate is included.

  Examples of the aromatic vinyl monomer include styrene and derivatives thereof such as styrene, methyl styrene, ethyl styrene, chlorostyrene, monofluoromethyl styrene, difluoro-methyl styrene, trifluoromethyl styrene.

  Examples of the olefinic hydrocarbon monomer include ethylene, propylene, butadiene, isobutylene, isoprene and 1,4-pentadiene.

  Examples of vinyl ester monomers include vinyl acetate.

  Examples of vinyl halide monomers include vinyl chloride and vinylidene chloride.

  Examples of the vinyl ether monomer include vinyl methyl ether.

  The copolymerization ratio of the monomer (c) in the intermediate copolymer is preferably 0 to 89% by mass with respect to the total amount of monomers constituting the intermediate copolymer.

  The number of functional groups D possessed by the compound (d) may be one or more. The functional group D is appropriately determined according to the type of the reactive functional group. For example, examples of the functional group D when the reactive functional group is a hydroxyl group include an acid halogen group and an isocyanate group. Examples of the compound (d) in this case include (meth) acrylic acid chloride and methacryloxyethyl isocyanate.

  An example of the functional group D when the reactive functional group is a carboxyl group includes an epoxy group. Examples of the compound (d) in this case include glycidyl vinyl ether, vinylcyclohexane monoepoxide and 1,3-butadiene monoepoxide.

  Examples of the functional group D when the reactive functional group is an isocyanate group include a hydroxyl group. Examples of the compound (d) in this case include hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, hydroxybutyl (meth) acrylate, ε-caprolactone adduct of hydroxyethyl (meth) acrylate, and isophorone diisocyanate (IPDI) 2-hydroxyethyl acrylate adducts are included.

  Examples of the functional group D when the reactive functional group is an epoxy group include a carboxyl group. Examples of the compound (d) in this case include (meth) acrylic acid, pentaerythritol triacrylate succinic anhydride adduct and (meth) acryloxyethyl phthalate.

  The compound (d) preferably has a functional group D of 100% by number or more based on the number of reactive functional groups that the intermediate copolymer has. As long as the radical polymerization reactivity of the siloxane-based vinyl copolymer is obtained, the number of functional groups D in the compound (d) may be less than 100% by number with respect to the number of reactive functional groups. .

  In addition, a vinyl copolymer described in JP-A-2007-77188 can be used as the siloxane-based vinyl copolymer.

  The weight average molecular weight of the siloxane-based vinyl copolymer is preferably 5,000 to 100,000 from the viewpoint of increasing the compatibility of the siloxane-based vinyl copolymer in the coating material described later. When the weight average molecular weight of the siloxane-based vinyl copolymer is smaller than 5,000, the siloxane-based vinyl copolymer is likely to be crystallized, and the productivity may be significantly reduced. If the weight average molecular weight of the siloxane-based vinyl copolymer is larger than 100,000, the hardness of the surface layer may be lowered, and the function of the intermediate transfer member may be impaired.

  The surface layer 16 preferably further contains metal oxide fine particles from the viewpoint of preventing the surface layer from being worn and reinforcing the surface layer. The shape of the metal oxide fine particles is not particularly limited. The particle diameter of the metal oxide fine particles is preferably 1 to 100 nm. This particle diameter may be, for example, a number average particle diameter or a catalog value. Examples of the metal oxide fine particles include alumina, tin oxide and titania. More preferred is alumina.

  The metal oxide fine particles are preferably surface-treated with a surface treatment agent containing a polyorganosiloxane chain B from the viewpoint of enhancing the dispersibility of the metal oxide fine particles in the surface layer. The polyorganosiloxane chain B may have the same structure as the polyorganosiloxane chain A contained in the siloxane-based vinyl copolymer, or may have a different structure. The number of polyorganosiloxane chains B in the surface treatment agent may be one or more.

  Examples of the surface treatment agent having the polyorganosiloxane chain B include methyl hydrogen polysiloxane and modified silicone oil. The molecular weight of these silicon compounds is, for example, 300 to 20,000, from the viewpoint of expression of desired properties as a surface treatment agent and ease of handling during surface treatment.

  The modified silicone oil is, for example, a silicon compound in which an organic group is introduced into a polyorganosiloxane chain. The organic group may be a side chain in the polyorganosiloxane chain, or may be introduced at either one end or both ends. Examples of the modified silicone oil include amino-modified silicone, epoxy-modified silicone, carbinol-modified silicone, mercapto-modified silicone, and carboxyl-modified silicone.

The intermediate transfer belt 10 satisfies the following formula.
I ₃₄₅₀ / I ₂₉₅₀ ≧ 0.5

The peak intensity ratio “I ₃₄₅₀ / I ₂₉₅₀ ” of 0.5 or more indicates that a sufficient amount of hydroxyl groups are present on the surface of the elastic layer 14. It is considered that the hydroxyl group on the surface of the elastic layer 14 interacts with a polar group such as an ester group in the acrylic material constituting the surface layer 16 to develop a strong bonding force.

Here, “I ₃₄₅₀ ” is the maximum absorption peak intensity appearing at 3400 ± 50 cm ⁻¹ of the infrared absorption spectrum when the surface 16 side surface of the elastic layer 14 is measured by the FT-IR ATR method. The peak intensity represents the abundance of hydroxyl groups (OH bonds) on the surface 16 side surface of the elastic layer 14. “I ₂₉₅₀ ” is the peak intensity of the maximum absorption that appears at 2950 ± 50 cm ⁻¹ of the infrared absorption spectrum when the surface 16 side surface of the elastic layer 14 is measured by the FT-IR ATR method. The peak intensity represents the abundance of hydrocarbon groups (C—H bonds) on the surface 16 side surface of the elastic layer 14. Both I ₃₄₅₀ and I ₂₉₅₀ are determined by subtracting the baseline intensity from the maximum absorption peak intensity of the infrared absorption spectrum, as shown in FIG. In FIG. 2, A ₁ indicates a region of 3400 ± 50 cm ⁻¹ and A ₂ indicates a region of 2950 ± 50 cm ⁻¹ . Baseline, a straight line connecting the intensity of the 2500 cm ^-1 strength and 4000 cm ^-1 in the infrared absorption spectrum.

  FT-IR is a Fourier Transform Infrared Spectrophotometer, and ATR method is an attenuated total reflection method. The FT-IR ATR method is performed by FT-IR to which the ATR method can be applied, such as a Spectrum One Fourier transform infrared absorption ATR apparatus (manufactured by PerkinElmer).

When the peak intensity ratio “I ₃₄₅₀ / I ₂₉₅₀ ” is smaller than 0.5, the adhesive strength of the surface layer 16 to the elastic layer 14 may be insufficient. If the intensity peak intensity ratio is too large, the effect of improving the adhesive strength of the surface layer 16 reaches its peak. From such a viewpoint, the peak intensity ratio is preferably 2 or less.

  The peak intensity can be measured by exposing the surface 16 side surface of the elastic layer 14 of the intermediate transfer belt 10. The surface 16 side surface of the elastic layer 14 can be exposed by excavating the surface layer 16 using a focused ion beam (FIB) processing observation apparatus. Alternatively, the surface can be exposed by immersing the intermediate transfer belt 10 in a solvent to swell the surface layer 16 and peeling it from the elastic layer 14. Examples of the solvent for swelling include water, a water-soluble lower alcohol such as methanol, ethanol and 2-propanol, a water-soluble organic solvent such as acetone and acetonitrile, and a mixed solution thereof.

The peak intensity ratio “I ₃₄₅₀ / I ₂₉₅₀ ” can be increased by opening the double bond in the rubber material on the surface 16 side surface of the elastic layer 14 and oxidizing it. The oxidation can be performed by chemically oxidizing the surface of the elastic layer 14 with an acidic treatment solution such as sulfuric acid or a mixed solution of hydrochloric acid and sodium hypochlorite. Alternatively, the oxidation can be performed by irradiating the surface of the elastic layer 14 with ultraviolet rays in the atmosphere.

[Method for producing intermediate transfer member]
The intermediate transfer member according to the present invention can be produced by the following method.
In this method, the first step of oxidizing the outer peripheral surface of the endless elastic layer and the coating material containing the surface layer material described above are applied to the outer peripheral surface of the oxidized elastic layer. A second step and a third step of curing the coating film by heating or irradiating the coating film of the coating formed on the outer peripheral surface of the elastic layer with an active energy ray.

  The first step can be performed by the above-described chemical oxidation treatment using the acidic treatment liquid, irradiation with ultraviolet rays in the atmosphere, or the like. The end point of the oxidation treatment or ultraviolet irradiation is determined, for example, by measuring the peak intensity ratio on the outer peripheral surface of the elastic layer and confirming that the ratio is 0.5 or more.

  In the second step, the paint contains the surface layer material described above. The coating material may further contain a solvent from the viewpoint of improving applicability. One or more solvents may be used. Examples of the solvent include various organic solvents such as alcohols, hydrocarbons, halogenated hydrocarbons, ethers, ketones, esters, and polyhydric alcohol derivatives.

  Moreover, the said coating material may further contain a polymerization initiator from a viewpoint of hardening acceleration. One or more polymerization initiators may be used. A polymerization initiator is selected according to the hardening method of a coating film. For example, in the third step, in the case where the coating film is cured by irradiation with active energy rays, a photopolymerization initiator is used as the polymerization initiator. Examples of photopolymerization initiators include benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin isobutyl ale, acetoin, butyroin, toluoin, benzyl, benzophenone, p-methoxybenzophenone, diethoxyacetophenone, 2,2- Dimethoxy-2-phenylacetophenone, methylphenylglyoxylate, ethylphenylglyoxylate, 4,4-bis (dimethylaminobenzophenone), 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1-hydroxy Carbonyl compounds such as cyclohexyl phenyl ketone and 1- (4-isopropylphenyl) -2-hydroxy-2-methylpropan-1-one; tetramethylthiuram disulfide, tetra Sulfur compounds such as tilthiuram disulfide; azo compounds such as azobisisobutyronitrile and azobis-2,4-dimethylvaleronitrile; peroxide compounds such as benzoyl peroxide and ditertiary butyl peroxide; and 2,4,6 -Phosphine oxide compounds such as trimethylbenzoyldiphenylphosphine oxide; The content of the photopolymerization initiator in the paint is, for example, preferably 0.1 to 20% by mass and more preferably 1 to 10% by mass with respect to the total amount of resin solids.

  In the case of the coating containing the siloxane-based vinyl copolymer, polyfunctional (meth) acrylate and metal oxide fine particles, the content of the siloxane-based vinyl copolymer is 100 parts by volume of the resin-based solid content in the coating. On the other hand, it is preferably 5 to 75 parts by volume, and more preferably 5 to 50 parts by volume. Here, the “resin-based solid content” includes a monomer and a resin component constituting the resin in the paint, and includes, for example, a siloxane-based vinyl copolymer, a polyfunctional (meth) acrylate, and a resin that is optionally blended. It is an organic component that becomes solids. If the content of the siloxane-based vinyl copolymer is less than 5 parts by volume, the surface free energy of the surface layer may not be sufficiently reduced. If the content of the siloxane-based vinyl copolymer is more than 75 parts by volume, sufficient strength and hardness of the surface layer may not be obtained.

  Moreover, it is preferable that content of polyfunctional (meth) acrylate in the said coating material is 25-95 volume parts with respect to 100 volume parts of said resin-type solid content from a viewpoint of raising the hardness of a surface layer, 50-95. More preferably, it is a volume part.

  Further, the content of the metal oxide fine particles in the paint is effective for reinforcing the surface layer by the metal oxide fine particles, and from the viewpoint of realizing a good dispersion state of the metal oxide fine particles in the paint. It is preferable that it is 10-70 volume parts with respect to 100 volume parts, and it is more preferable that it is 10-50 volume parts. The content of the metal oxide fine particles in the coating film can be adjusted by, for example, the coating amount and the number of coatings of the paint.

  The coating material is applied to at least the outer peripheral surface of the endless belt-like elastic layer by a known method such as immersion, spraying, or application. For example, in the case of dip coating, the paint is applied to the outer peripheral surface of the elastic layer by a dip coating device. The dip coating apparatus includes, for example, a dip tank in which the paint and the elastic layer are accommodated, and a paint supply apparatus that continuously supplies the paint to the dip tank and collects and recharges the paint overflowing from the dip tank. A belt conveying device that accommodates and lifts the elastic layer to be immersed in the immersion tank. The speed at which the elastic layer is pulled up is appropriately determined according to the viscosity of the paint. For example, when the viscosity of the paint is 10 to 200 mPa · s, the speed of pulling up the elastic layer is 0.5 to 15 mm from the viewpoint of the thickness and uniformity of the coating film of the paint and the optimization of the drying speed. / Second is preferred.

In the third step, sufficient energy is applied to the coating film to cure the coating film of the paint. For example, in the case of irradiation with active energy rays, the irradiation dose is preferably 100 mJ / cm ² or more from the viewpoint of prevention of uneven coating curing, optimization of hardness, curing time, curing rate, and the like. more preferably 120~200mJ / cm ^2, further preferably 150~180mJ / cm ^2. The irradiation dose can be measured by, for example, UIT250 (made by USHIO INC.). Irradiation of active energy rays to the coating film can be performed by an irradiation apparatus having an active energy irradiation source.

  For example, the irradiation device includes a support device that rotatably supports an endless belt-like elastic layer formed on the outer peripheral surface of the coating film, and an active energy toward the outer peripheral surface of the rotating elastic layer. An irradiation source for irradiating the line. The rotational speed (circumferential speed) of the elastic layer in the support device is preferably 10 to 300 mm / second, for example, from the viewpoint of prevention of uneven curing, optimization of hardness and curing time, and the like.

  Examples of the active energy rays include ultraviolet rays, electron beams and γ rays. The active energy ray is preferably an ultraviolet ray or an electron beam. From the viewpoint of easy handling, ultraviolet rays are preferable. Examples of ultraviolet radiation sources include low pressure mercury lamp, medium pressure mercury lamp, high pressure mercury lamp, ultra high pressure mercury lamp, carbon arc lamp, metal halide lamp, xenon lamp, ArF excimer laser, KrF excimer laser, excimer lamp and synchrotron radiation generation Device included. The ultraviolet light is, for example, ultraviolet light having a wavelength of 400 nm or less.

  Examples of the electron beam irradiation source include various electron beam accelerators such as a Cockloft Walton type, a bandegraph type, a resonant transformation type, an insulating core transformer type, a linear type, a dynamitron type, and a high frequency type. Examples of the electron beam include an electron beam having an energy of 50 to 1000 keV, preferably 100 to 300 keV.

  The irradiation time of the active energy ray is appropriately determined from the viewpoint of the curing efficiency and work efficiency of the coating film. The irradiation time is preferably 0.5 seconds to 5 minutes, and more preferably 3 seconds to 2 minutes.

  The concentration of oxygen in the atmosphere in the irradiation of active energy rays in the third step is preferably 5% by volume or less, more preferably 1% by volume or less from the viewpoint of preventing oxidation of the formed surface layer. preferable. The oxygen concentration is adjusted by supplying other gas such as nitrogen gas into the atmosphere. The oxygen concentration can be measured with an atmospheric gas management oxygen concentration meter OX100 (manufactured by Yokogawa Electric Corporation).

  Moreover, the said coating film can be hardened | cured by heating with well-known heating apparatuses, such as a halogen heater, an infrared heater, and a warm air heater. The temperature in the heating chamber in which the endless belt-like elastic layer having a coating film is accommodated for heating is, for example, 140 to 160 ° C.

  Said method may further include other processes other than the 1st to 3rd process in the range in which the effect of this invention is acquired. Examples of such other steps include a step of heating and drying the coating film formed in the second step. The heating method in this drying process is, for example, blowing warm air. The temperature of the hot air is, for example, preferably 40 to 100 ° C., more preferably 40 to 80 ° C., from the viewpoint of evaporating the solvent in the paint and suppressing the influence on the coating film, and more preferably 40 to 80 ° C. More preferably, it is 60 degreeC.

  Moreover, the example of said other process includes the process of producing the base material mentioned above before a 1st process. Examples of steps for producing an endless belt-like base material include, for example, those described in JP-A-61-95361, JP-A-64-22514 and JP-A-3-180309. A step of heating the polyamic acid coating applied to the surface of the cylindrical substrate to imidize the polyamic acid and recovering the obtained endless belt-like film as a substrate.

  When the surface layer 16 made of an acrylic material is formed on the surface of the elastic layer 14 having hydroxyl groups on the entire surface, the surface layer 16 is formed on the surface of the elastic layer not having hydroxyl groups. The adhesive strength of the surface layer 16 is increased. This is because the hydroxyl group on the surface of the elastic layer 14 interacts with polar groups such as an ester bond, an ether bond, a carbonyl group, a carboxyl group, and a hydroxyl group in the acrylic material constituting the surface layer 16, and hydrogen is interposed between them. This is probably because a bond is formed. For this reason, the layers (elastic layer and surface layer) composed of materials that are not necessarily good in adhesion, such as a rubber material and an acrylic material, are directly bonded with sufficient adhesive strength without using an adhesive. The intermediate transfer belt 10 having the elastic layer 14 and the surface layer 16 is suitably used as an intermediate transfer member in the image forming apparatus.

[Image forming apparatus]
The image forming apparatus according to the present invention includes at least an intermediate transfer member for transferring a toner image formed on the photosensitive member to a recording medium. The image forming apparatus according to the present invention can be configured in the same manner as a known image forming apparatus having an intermediate transfer member except that the image forming apparatus includes the intermediate transfer member according to the present invention. The image forming apparatus according to the present invention includes, for example, a photosensitive member, a charging device that charges the photosensitive member, an exposure device that forms an electrostatic latent image by irradiating the charged photosensitive member with light, and an electrostatic latent image is formed. A developing device for supplying toner to the photosensitive member to form a toner image corresponding to the electrostatic latent image, a transfer device including an intermediate transfer member for transferring the toner image formed on the electrostatic latent image to a recording medium, and And a fixing device for fixing the toner image to the recording medium. “Toner image” refers to a state where toner is gathered in an image form.

  FIG. 3 is a diagram schematically showing a configuration of an image forming apparatus according to an embodiment of the present invention. As illustrated in FIG. 3, the image forming apparatus 1 includes an image reading unit 110, an image processing unit 30, an image forming unit 40, a paper transport unit 50, and a fixing device 60.

  The image forming unit 40 includes image forming units 41Y, 41M, 41C, and 41K that form images of toners of Y (yellow), M (magenta), C (cyan), and K (black). Since these have the same configuration except for the toner to be accommodated, the symbols representing the colors may be omitted hereinafter. The image forming unit 40 further includes an intermediate transfer unit 42 and a secondary transfer unit 43. These correspond to a transfer device.

  The image forming unit 41 includes an exposure device 411, a developing device 412, a photosensitive drum 413, a charging device 414, and a drum cleaning device 415. The photoreceptor drum 413 is, for example, a negatively charged organic photoreceptor. The surface of the photosensitive drum 413 has photoconductivity. The photoconductor drum 413 corresponds to a photoconductor. The charging device 414 is, for example, a corona charger. The charging device 414 may be a contact charging device that charges a contact charging member such as a charging roller, a charging brush, or a charging blade by contacting the photosensitive drum 413. The exposure apparatus 411 is composed of, for example, a semiconductor laser. The developing device 412 is, for example, a two-component developing type developing device.

  The intermediate transfer unit 42 includes an intermediate transfer belt 421, a primary transfer roller 422 that presses the intermediate transfer belt 421 against the photosensitive drum 413, a plurality of support rollers 423 including a backup roller 423A, and a belt cleaning device 426. The intermediate transfer belt 421 is an endless belt. The intermediate transfer belt 421 is looped around the plurality of support rollers 423. When at least one drive roller of the plurality of support rollers 423 rotates, the intermediate transfer belt 421 travels at a constant speed in the arrow A direction. The intermediate transfer belt 421 corresponds to an intermediate transfer member.

  The secondary transfer unit 43 has a plurality of support rollers 431 including an endless secondary transfer belt 432 and a secondary transfer roller 431A. The secondary transfer belt 432 is stretched in a loop by the secondary transfer roller 431A and the support roller 431.

  The fixing device 60 covers the fixing roller 62, the outer peripheral surface of the fixing roller 62, an endless heat generating belt 63 for heating and melting the toner constituting the toner image on the paper S, and the paper S to the fixing roller 62. And a pressure roller 64 that presses toward the heat generating belt 63. The paper S corresponds to a recording medium.

  The image forming apparatus 1 further includes an image reading unit 110, an image processing unit 30, and a paper transport unit 50. The image reading unit 110 includes a paper feeding device 111 and a scanner 112. The paper transport unit 50 includes a paper feed unit 51, a paper discharge unit 52, and a transport path unit 53. In the three paper feed tray units 51a to 51c constituting the paper feed unit 51, paper S (standard paper, special paper) identified based on basis weight, size, etc. is stored for each preset type. . The conveyance path unit 53 includes a plurality of conveyance roller pairs such as registration roller pairs 53a.

Image formation by the image forming apparatus 1 will be described.
The scanner 112 optically scans and reads the document D on the contact glass. Reflected light from the document D is read by the CCD sensor 112a and becomes input image data. The input image data is subjected to predetermined image processing in the image processing unit 30 and sent to the exposure device 411.

  The photosensitive drum 413 rotates at a constant peripheral speed. The charging device 414 uniformly charges the surface of the photosensitive drum 413 to a negative polarity. The exposure device 411 irradiates the photosensitive drum 413 with laser light corresponding to the input image data of each color component. Thus, an electrostatic latent image is formed on the surface of the photosensitive drum 413. The developing device 412 visualizes the electrostatic latent image by attaching toner to the surface of the photosensitive drum 413. In this way, a toner image corresponding to the electrostatic latent image is formed on the surface of the photosensitive drum 413.

  The toner image on the surface of the photosensitive drum 413 is transferred to the intermediate transfer belt 421 by the intermediate transfer unit 42. Transfer residual toner remaining on the surface of the photosensitive drum 413 after the transfer is removed by a drum cleaning device 415 having a drum cleaning blade that is in sliding contact with the surface of the photosensitive drum 413.

  When the intermediate transfer belt 421 is pressed against the photosensitive drum 413 by the primary transfer roller 422, the toner images of the respective colors are sequentially transferred onto the intermediate transfer belt 421.

  On the other hand, the secondary transfer roller 431A is pressed against the backup roller 423A via the intermediate transfer belt 421 and the secondary transfer belt 432. Thereby, a transfer nip is formed. The sheet S passes through this transfer nip. The paper S is transported to the transfer nip by the paper transport unit 50. The correction of the inclination of the sheet S and the adjustment of the conveyance timing are performed by a registration roller unit provided with a registration roller pair 53a.

  When the sheet S is conveyed to the transfer nip, a transfer bias is applied to the secondary transfer roller 431A. By applying the transfer bias, the toner image carried on the intermediate transfer belt 421 is transferred onto the paper S. The sheet S on which the toner image is transferred is conveyed toward the fixing device 60 by the secondary transfer belt 432.

  The fixing device 60 heats and pressurizes the conveyed paper S at the nip portion. Thus, the toner image is fixed on the paper S. The paper S on which the toner image has been fixed is discharged out of the apparatus by a paper discharge unit 52 having a paper discharge roller 52a.

  Note that transfer residual toner remaining on the surface of the intermediate transfer belt 421 after the secondary transfer is removed by a belt cleaning device 426 having a belt cleaning blade that is in sliding contact with the surface of the intermediate transfer belt 421.

  When the intermediate transfer belt 421 is in pressure contact with the photosensitive drum 413, the intermediate transfer belt 421 is deformed according to the elasticity of the elastic layer of the intermediate transfer belt 421 according to the surface shape of the photosensitive drum 413. The surface layer on the elastic layer adheres to the entire surface of the elastic layer and sufficiently follows the deformation of the elastic layer. Therefore, the intermediate transfer belt 421 is in close contact with the photosensitive drum 413. Similarly, when the intermediate transfer belt 421 comes into pressure contact with the paper S pressed by the backup roller 423A, the intermediate transfer belt 421 is also in close contact with the paper S. As described above, the intermediate transfer belt 421 is excellent in contact with the photosensitive drum 413 and the paper S.

  Furthermore, since the intermediate transfer belt 421 has the above-described surface layer, it is excellent in durability in contact with the photosensitive drum 413 and the paper S. Since the surface layer is bonded to the elastic layer with sufficient adhesive strength, the surface layer is not peeled off from the elastic layer even if stress is applied to the intermediate transfer belt 421 due to the above-described pressure contact. Therefore, the image forming apparatus 1 can stably form a high quality image over a long period of time.

  When the intermediate transfer belt 421 has a surface layer further containing the above-described siloxane-based vinyl copolymer and metal oxide fine particles, the film transfer resistance and durability of the intermediate transfer belt 421 are further improved, and surface freeness thereof is improved. It is even more effective from the viewpoint of keeping the energy lower.

[Preparation of resin substrate]
A seamless belt having a thickness of 60 μm made of polyamideimide containing the conductive agent described above was prepared. This is referred to as a “resin base”.

[Preparation of surface coating]
The following A component was put into a container, stirred and dispersed with a stirring blade, and then the following B component was further added to prepare a surface layer coating material. “Full shade RS” is a composition containing a polysiloxane compound containing one terminal methacryloxy group. “Irgacure” is a registered trademark of BASF, and “Full Shade” is a registered trademark of Toyo Ink SC Holdings Co., Ltd.
(A component)
Acrylic monomer (Full shade RS, manufactured by Toyochem Co., Ltd.) 100 parts by mass Urethane acrylate (AU-3110, manufactured by Tokushiki Co., Ltd.) 25 parts by mass Propylene glycol monomethyl ether acetate 1000 parts by mass (component B)
Photoinitiator (Irgacure 379, manufactured by BASF) 5 parts by mass

[Example 1]
(1. Production of elastic layer belt 1)
An elastic layer made of chloroprene rubber (CR) having a thickness of 150 μm was formed on the outer peripheral surface of the resin substrate by a dipping coating method, whereby an elastic layer belt 1 was obtained.

(2. Production of surface-treated elastic layer belt)
The elastic layer belt 1 was fitted on a cylindrical substrate, and the surface of the elastic layer belt 1 was treated by irradiating the surface of the elastic layer with light under the following light irradiation condition 1 while rotating the cylindrical substrate. In the following light irradiation condition 1, “irradiation distance” is a distance from the light irradiation port to the surface of the elastic layer. The “irradiation time” is the time during which the cylindrical substrate is rotated. The surface-treated elastic layer belt 1 is referred to as “surface-treated elastic layer belt 1”.
(Light irradiation condition 1)
Type of light source: high pressure mercury lamp (H04-L41, manufactured by Eye Graphics Co., Ltd.)
Irradiation distance: 100mm
Irradiation quantity: 1 J / cm ²
Irradiation time: 15 minutes

(3. Measurement of infrared absorption peak intensity)
The infrared absorption spectrum of the surface of the surface-treated elastic layer belt 1 was measured at a resolution of 4 cm ⁻¹ and 4 times of integration using a Spectrum One Fourier transform infrared absorption ATR apparatus manufactured by PerkinElmer. Then, to the peak intensity _{I 2950} of the maximum absorption appears at 2950 ± 50 cm ^-1, 3400 to determine the ratio of the maximum absorption peak intensity _{I 3450} appearing at _{^{± 50cm -1 (I 3450 / I}} 2950). Each peak intensity is the maximum absorption intensity value minus the baseline intensity value. Baseline, a straight line connecting the intensity values of the intensity values and 4000 cm ^-1 in 2500 cm ^-1 in the spectrum. I ₃₄₅₀ / I ₂₉₅₀ of the surface-treated elastic layer belt 1 was 0.60.

(4. Preparation of surface layer)
Next, a surface layer coating material is applied to the surface of the surface-treated elastic layer belt 1 by a dip coating method using a dip coating apparatus as described above so that the dry film thickness becomes 2 μm, and the coating liquid is applied. A membrane was prepared. The coating conditions for the surface layer coating are shown below.
(Application conditions)
Coating liquid supply rate (circulation rate): 1 L / min Pulling speed of the surface-treated elastic layer belt 1: 4.5 mm / min

Next, the surface-treated elastic layer belt 1 on which the coating film has been formed is externally fitted to a cylindrical substrate, and the coating film is irradiated with light under the following light irradiation conditions 2 while rotating the cylindrical substrate, and is cured to form a surface layer. Was made. Thus, an endless belt-like intermediate transfer member 1 was obtained.
(Light irradiation condition 2)
Type of light source: high pressure mercury lamp (H04-L41, manufactured by Eye Graphics Co., Ltd.)
Irradiation distance: 100mm
Irradiation quantity: 1 J / cm ²
Irradiation time: 240 seconds

In addition, using a cryo-focused ion beam (FIB) processing observation device, under a liquid nitrogen circulation, a region having a diameter of several μm in the surface layer of the intermediate transfer body 1 is shaved at −192 ° C., and the surface layer in the region is removed. The surface of the elastic layer was exposed. And the infrared absorption spectrum of the exposed part was measured as mentioned above. As a result, I ₃₄₅₀ / I ₂₉₅₀ in the exposed portion was 0.60. From the above, the ratio of the surface of the elastic layer exposed by scraping the surface of the intermediate transfer member 1 is substantially the same as the ratio of the surface of the elastic layer measured in the process of manufacturing the intermediate transfer member 1. It was confirmed to be the same. Moreover, since the said ratio was substantially the same as mentioned above, it was confirmed that the change of the form of the hydroxyl group of an elastic layer has not arisen.

[Example 2]
An elastic layer belt 2 was obtained in the same manner as the elastic layer belt 1 except that NBR (nitrile butadiene rubber) was used instead of CR. Then, an intermediate transfer member 2 was obtained in the same manner as in Example 1 except that the elastic layer belt 2 was used instead of the elastic layer belt 1. The I ₃₄₅₀ / I ₂₉₅₀ of the surface-treated elastic layer belt 2 was 0.55.

[Comparative Examples 1-4]
An intermediate transfer member 3 was obtained in the same manner as in Example 1 except that the surface treatment of the elastic layer belt 1 was not performed. When I ₃₄₅₀ / I ₂₉₅₀ of the elastic layer belt 1 was measured, the ratio was 0.

Further, an intermediate transfer member 4 was obtained in the same manner as in Example 1 except that the irradiation time in the surface treatment of the elastic layer belt 1 was set to 1 minute. I ₃₄₅₀ / I ₂₉₅₀ of the surface-treated elastic layer belt 4 was 0.40.

Similarly, an intermediate transfer member 5 was obtained in the same manner as in Example 2 except that the surface treatment of the elastic layer belt 2 was not performed. When I ₃₄₅₀ / I ₂₉₅₀ of the elastic layer belt 2 was measured, the ratio was 0.15.

Further, an intermediate transfer member 6 was obtained in the same manner as in Example 2 except that the irradiation time in the surface treatment of the elastic layer belt 2 was set to 1 minute. I ₃₄₅₀ / I ₂₉₅₀ of the surface-treated elastic layer belt 6 was 0.45.
Table 1 shows materials, irradiation times, and peak intensity ratios of the intermediate transfer members 1 to 6.

[Evaluation of intermediate transfer member]
A full-color image forming apparatus as shown in FIG. 3 was prepared as an evaluation machine. This evaluation machine is a device obtained by modifying bizhub PRO C6500 (laser exposure, reversal development, tandem color composite machine of intermediate transfer body) manufactured by Konica Minolta Business Technologies, Inc. so that intermediate transfer bodies 1 to 6 can be mounted.

(1) Transfer rate The exposure amount in the evaluation machine is optimized, and intermediate transfer members 1 to 6 are mounted on the evaluation machine, respectively, and at 20 ° C. and 50% RH, yellow (Y), magenta (M), cyan (C ) And black (Bk) each having a printing rate of 2.5% was printed on a neutral sheet of 1 million sheets.
Next, using a suction device, a toner having a predetermined area (three points of 10 mm × 50 mm) on the surface of the intermediate transfer body 1 after the primary transfer and before the secondary transfer is collected, and before the secondary transfer. The toner weight A (g) was measured.
Next, the transfer residual toner on the intermediate transfer body 1 after the secondary transfer was collected with a booker tape and attached to a white paper. Then, the color of the white paper was measured, and the weight B (g) of the untransferred toner was obtained from the relationship between the toner weight and the colorimetric value measured in advance. A spectrocolorimeter (Konica Minolta Sensing Co., Ltd., CM-2002) was used for color measurement of white paper.
Then, the transfer rate η (%) was obtained from the following formula, and the transfer rates of the intermediate transfer members 1 to 6 were evaluated based on the following criteria.
(formula)
η (%) = {1− (B / A)} × 100
(Evaluation criteria for transfer rate)
A: Transfer rate is 98% or more and 100% or less O: Transfer rate is 95% or more and less than 98% Δ: Transfer rate is 90% or more and less than 95% ×: Transfer rate is less than 90%

(2) Scratch resistance One million sheets were printed by the same method as the evaluation of “(1) Transfer rate”. The surface state of each of the intermediate transfer members 1 to 6 was observed before and after printing, and scratches in a 100 mm × 100 mm portion on the surface were counted. Then, scratch resistance of the intermediate transfer belt 1 was evaluated based on the following criteria.
(Evaluation criteria for scratch resistance)
◎: No flaws ○: Number of flaws is 1 or more and less than 6 △: Number of flaws is 6 or more and less than 11 ×: Number of flaws is 11 or more

(3) Peeling resistance 3 million sheets were printed by the same method as the evaluation of “(1) Transfer rate”. The surface state of the intermediate transfer member was observed before and after printing, and the area Sp (cm ² ) of the surface layer where the surface layer in the 100 mm × 100 mm portion was peeled off was measured. Calculated.
(Formula) Rp = {Sp (cm ² ) / 100 cm ² } × 100
Then, the peeling resistance of the intermediate transfer body 1 was evaluated based on the following criteria.
(Evaluation criteria for peeling resistance)
A: Rp is less than 0.1% B: Rp is 0.1% or more and less than 1.0% Δ: Rp is 1.0% or more and less than 5.0% ×: Rp is 5.0% or more

(4) Filming resistance One million sheets were printed by the same method as the evaluation of “(1) Transfer rate”. Each color difference (color difference) ΔE of the intermediate transfer bodies 1 to 6 before and after printing was determined. A spectrocolorimeter (Konica Minolta Sensing Co., Ltd., CM-2002) was used to measure the color of the intermediate transfer body before and after printing. Then, a difference ΔE between color values before and after printing was calculated. From the calculated ΔE, the filming resistance of each of the intermediate transfer members 1 to 6 was evaluated based on the following criteria. Good filming resistance means low surface free energy characteristics.
(Filming resistance evaluation criteria)
A: ΔE is 0 or more and less than 1 ○: ΔE is 1 or more and less than 4 Δ: ΔE is 4 or more and less than 6 ×: ΔE is 6 or more Table 2 shows the evaluation results of the intermediate transfer members 1 to 6.

  As is apparent from Table 2, the intermediate transfer members 1 and 2 gave good results in all of the transfer rate, scratch resistance, peeling resistance and filming resistance. This is presumably because a sufficient amount of hydroxyl groups were present on the surface of the elastic layer, and these hydroxyl groups interacted with the acrylic material on the surface layer to develop high adhesiveness. In particular, the intermediate transfer member 1 shows better performance than the intermediate transfer member 2. Therefore, it is considered that the higher the peak intensity ratio, the higher the adhesiveness.

  On the other hand, with the intermediate transfer members 3 to 6, good results were not obtained in all of the transfer rate, scratch resistance, peeling resistance, and filming resistance. This is probably because hydroxyl groups were not substantially present on the surface of the elastic layer, or the amount of hydroxyl groups present on the surface was insufficient. Further, the ultraviolet irradiation time of the intermediate transfer members 4 and 6 is as short as 1 minute, but the peak intensity ratio is 0.4 and 0.45, which are close to those of the intermediate transfer members 1 and 2, respectively. From this, it is possible to enhance the adhesion between the elastic layer and the surface layer by irradiating the surface of the elastic layer with a small amount of ultraviolet rays, however, the elastic layer and the surface layer that can be used as an intermediate transfer member. It can be seen that in order to obtain the adhesive property, it is necessary to irradiate the surface of the elastic layer more sufficiently with ultraviolet rays.

  According to the present invention, by introducing a sufficient amount of hydroxyl groups to the surface of the rubber material, the adhesive strength of the acrylic material to the rubber material can be increased. Therefore, the present invention is not limited to providing an intermediate transfer member suitable for an image forming apparatus, and contributes to the development and spread of a technique for directly bonding a material having substantially no polar group and a material having a polar group. Is expected to do.

DESCRIPTION OF SYMBOLS 1 Image forming apparatus 10,421 Intermediate transfer belt 12 Base material 14 Elastic layer 16 Surface layer 30 Image processing part 40 Image forming part 41Y, 41M, 41C, 41K Image forming unit 42 Intermediate transfer unit 43 Secondary transfer unit 50 Paper conveyance part 51 Paper feed unit 51a, 51b, 51c Paper feed tray unit 52 Paper discharge unit 52a Paper discharge roller 53 Transport path part 53a Registration roller pair 60 Fixing device 62 Fixing roller 63 Heating belt 64 Pressure roller 110 Image reading unit 111 Paper supply device 112 Scanner 112a CCD sensor 411 Exposure device 412 Development device 413 Photosensitive drum 414 Charging device 415 Drum cleaning device 422 Primary transfer roller 423 Support roller 423A Backup roller 426 Belt cleaning device 31 support rollers 431A secondary transfer roller 432 Secondary transfer belt D document S Paper

Claims (4)

An intermediate transfer member, which is an intermediate transfer member formed by overlapping an elastic layer made of a rubber material and a surface layer made of an acrylic material in this order, and satisfies the following formula.
I ₃₄₅₀ / I ₂₉₅₀ ≧ 0.5
(In the above formula, I ₃₄₅₀ is the peak intensity of the maximum absorption that appears at 3400 ± 50 cm ⁻¹ of the infrared absorption spectrum when the surface of the elastic layer is measured by the FT-IR ATR method. ₂₉₅₀ is the maximum absorption peak intensity appearing at 2950 ± 50 cm ⁻¹ of the infrared absorption spectrum when the surface of the elastic layer is measured by the FT-IR ATR method.)   The intermediate transfer member according to claim 1, wherein the rubber material includes chloroprene rubber or nitrile butadiene rubber. The surface layer is a cured film of a coating containing a siloxane-based vinyl copolymer, polyfunctional (meth) acrylate, and metal oxide fine particles, by irradiation with active energy rays,
The siloxane-based vinyl copolymer includes one or more polyorganosiloxane chains A and three or more radical polymerizable double bonds, and has a weight average molecular weight of 5,000 to 100,000.
The intermediate transfer member according to claim 1, wherein the metal oxide fine particles are surface-treated with a surface treatment agent containing a polyorganosiloxane chain B. In an image forming apparatus having at least an intermediate transfer body for transferring a toner image formed on a photoreceptor to a recording medium,
The image forming apparatus, wherein the intermediate transfer member is the intermediate transfer member according to any one of claims 1 to 3.

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