JP2000122333A - Electrophotographic body to be transferred and image forming method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To embody an electrophotographic body to be transferred having oilless fixability, high image quality, high color developability, excellent offset resistance and an excellent presservability and an image forming method using the same. SOLUTION: A thermoplastic resin, in which the minimal of tan σof a binder resin exists, from a glass transition temperature (Tg) to a temperature. at which a loss elastic modulus (G") attains G"=1×104 Pa to each other, the minimal value of the tan σis below 1.2, a storage elastic modules (G') at the temperature. at the minimal of the tan σ is >=G'=5×105 Pa and the value of tan σat the temperature. at which G"=1×104 Pa is attained is >=1.0, is used for the thermoplastic resin of the electrophotographic body to be transferred having an image receiving layer consisting of the thermoplastic resin on, at least, one surface of a substrate having a heat resistance of >=100 deg.C. The thermoplastic resin constituting the image receiving layer preferably contains a linear polyester resin not having a crosslinking deterioration in it molecule.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transfer device for electrophotography (hereinafter simply referred to as "transfer member") used in an apparatus utilizing an electrophotographic process, such as a copying machine, a printer, a facsimile, etc., particularly a color copying machine. ) And an image forming method.

[0002]

2. Description of the Related Art In an electrophotographic process, a latent image is formed electrically on a photoreceptor using a photoconductive substance by various means, and the latent image is developed using toner. After transferring the toner image to a transfer object such as paper, with or without the intermediate image via an intermediate transfer member, fixing the transferred image to a transfer target such as paper, through a plurality of steps of fixing An image is formed. In recent years, with the development of equipment in the information society and the enhancement of communication networks, the electrophotographic process has been widely used not only for copiers but also for printers.
There is an increasing demand for smaller, lighter, faster, and more reliable devices.

In particular, in the case of color electrophotography, it is required that an image to be formed has high image quality and high coloring. In order to obtain a high-quality and high-color image, the toner must be sufficiently melted and the surface of the image after fixing must be smooth from the viewpoint of translucency and gloss. For this reason, the fixing step in the electrophotographic process is particularly important.

[0004] As a contact-type fixing method widely used as a fixing method, a method using heat and pressure at the time of fixing (hereinafter, referred to as a "heat-compression bonding method") is general. In the case of this thermocompression bonding method, since the surface of the fixing member and the toner image on the transfer-receiving member come into contact with each other under pressure, the heat efficiency is extremely good and the fixing can be performed quickly. Very effective.

However, in the case of the thermocompression bonding method, since the surface of the fixing member and the toner image come into pressure contact with each other in a heated and melted state, a part of the toner image is transferred while being adhered to the surface of the fixing member. Offset and wrapping phenomenon may occur.Particularly, in color toner fixing, it is necessary to apply sufficient heat and pressure to the toner as compared with the black and white toner fixing due to the necessity of melting and mixing a plurality of color toners. It is necessary to release the thick toner layer that is in a molten state and overlaps a plurality of colors without offset or wrapping phenomenon. It was difficult.

As a simple method for preventing the toner from adhering to the surface of the fixing member, coating the surface of the fixing member with silicone oil or the like as an anti-offset liquid is performed. However, when oil or the like is used, adhesion of the oil to the transfer receiving body and image after fixing becomes a problem,
Further, there is a problem that a tank for storing oil and the like is required in the fixing device, and it is difficult to reduce the size of the device, and replenishment of the oil is complicated, which limits cost reduction.

Conventionally, the amount of the oil or the like applied to a general transfer receiving body in color fixing is as large as about 8.0 × 10 ^-2 mg / cm ² , whereas the amount of oil applied to a monochrome printer is large. The amount is not used at all, or 8.0 × 10 ⁻⁴ mg / cm ^2, which is one hundredth of the color fixing oil application amount even when used, and the above-mentioned drawbacks hardly cause practical problems. Therefore, in color fixing, there is a strong desire to be able to fix with the same oil application amount as black and white, and therefore, the releasability of the toner can be improved without depending on the fixing device, such as resin for resin or wax. Various methods have been proposed to improve by improvement.

Conventionally, for presentation and the like, an image is formed on a transparent film by an electrophotographic method, and a transparent film having a toner image is supplied to an overhead projector (hereinafter abbreviated as "OHP") to produce a projected image. It is widely done to get. However, if a color image is simply formed on a substrate such as polyethylene terephthalate (hereinafter abbreviated as “PET”), a projected image, particularly a halftone image, may not be sufficiently colored and may be turbid. There is. This is because, when fixing, the toner-fixed portion rises in a semi-elliptical shape, and light incident from the substrate side is scattered on the toner surface when exiting the toner layer. This phenomenon is conspicuous in a toner density region where adjacent toners do not fuse with each other, particularly in a halftone region, and makes the projected image turbid.

In order to improve light transmittance, Japanese Patent Application Laid-Open No. 63-92964 proposes a method in which a transparent resin layer is provided on a heat-resistant base material and a toner image is formed thereon. Have been. This method has a large effect of improving the color developing property, and similar methods are disclosed in JP-A-63-92965 and JP-A-02-2965.
63642, JP 03-198063, JP 04-125
Many are disclosed in JP-A-567, JP-A-04-212168 and the like. However, any of these methods is effective in combination with a conventional color toner having a sharp melt property, and therefore, when no release agent such as oil is applied to the fixing device, or when the amount of application is small. When the amount was small, the offset resistance was not sufficient.

Japanese Patent Application Laid-Open No. 05-104868 discloses a transfer film in which a transparent thermoplastic resin layer containing a wax having a melting point of 90 ° C. to 170 ° C. is provided on a substrate to improve offset resistance. Proposed. However, when an image receiving layer is formed of a conventional resin having sharp melt properties used for a color toner, a large amount of wax must be contained, and light transmittance is impaired. Further, since a styrene-acrylic resin is used for the image receiving layer, the releasability is insufficient, and if the molecular weight is increased to give the releasability, the color developing property is impaired.

Japanese Patent Application Laid-Open No. H09-160278 discloses that an image receiving layer contains a thermoplastic resin having a Tg of 70 ° C. or less and a release agent, and a temperature of 150 ° C. between a polytetrafluoroethylene resin tape and the image receiving layer. A method of improving the peeling property by setting the 180 ° peel strength to 0.1 N / 25 mm or less in the above is disclosed. However, while the heating time during actual fixing is extremely short, in the peeling test, it takes time to bond the resin tape and the image receiving layer, and during that time, the release agent in the image receiving layer is not adhered to the tape. It exudes to the interface, which is completely different from the amount of the release agent that exudes during actual fixing. For this reason, even if the peel strength of the image receiving layer is small, the offset resistance is often insufficient.

Japanese Patent Application Laid-Open No. 09-218527 discloses a transfer-receiving film in which an image receiving layer contains a release agent having a melting point of 40 ° C. to 120 ° C. to thereby improve the offset resistance. However, when the release property of the image receiving layer is obtained by a release agent, when fixing an image in which toners of a plurality of colors are overlapped, the thickness of the toner and the thickness of the image receiving layer are added, and the toner is added to the toner during peeling. The loss of applied strain and stress increases, and the offset resistance becomes insufficient.

Japanese Patent Application Laid-Open No. 04-359258 discloses a method of providing an image-receiving layer comprising a light-transmitting rubber-based resin, particularly a styrene-butadiene-based block elastomer, on a substrate. The publication discloses a method in which a styrene-butadiene block copolymer is contained in an image receiving layer and the viscoelastic range of the image receiving layer is at a specific value to improve offset resistance. However, when a crystalline polymer is used, the volume of the polymer changes due to a change in temperature.Therefore, the toner tends to be peeled off from the image receiving layer, and the resin crystallizes when heated in a drying process during manufacturing. There is a problem that the layer is easily clouded and it is difficult to control the production conditions. Further, when a resin having a high degree of crosslinking is used, the amount of toner embedded in the image receiving layer decreases,
The halftone color developability of the projected image becomes insufficient.

Japanese Patent Application Laid-Open No. 09-22136 discloses that an image receiving layer comprises a carboxylic acid unit selected from 2,6-naphthalenedicarboxylic acid and terephthalic acid and a sulfobenzenedicarboxylic acid as an acid component, and ethylene glycol, There is disclosed a method of improving color developability and anti-offset property by being formed of a polyester containing triethylene glycol and bisphenol A ethylene oxide adduct as an alcohol component. However, since the molecular weight of the resin of the image receiving layer is small, it is hard to say that the offset resistance is sufficient when the amount of applied oil is reduced.

Japanese Unexamined Patent Publication No. 09-311497 discloses that the resin forming the image receiving layer has at least two peaks or shoulders in the molecular weight distribution measured by GPC, so that the offset resistance and the color development can be improved. A method of balancing is disclosed. Such a resin is composed of a high molecular weight component and a low molecular weight component, but as described above, when the amount of oil applied is reduced due to the presence of the low molecular weight component in the molecule, the fixing roll Wrapping around.

As described above, even in fixing with a small amount of oil applied or oilless fixing without sacrificing the properties of the toner itself, an offset resistance is maintained and a light transmission image excellent in color development is formed. A method is needed.

[0017]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned conventional problems, and to provide an electrophotographic transfer member suitable for forming an image with a color toner and a light transmission image, and using the same. An object of the present invention is to provide an image forming method. That is, an object of the present invention is to provide a transferability for electrophotography which has a fixing suitability with a small amount of oil applied or less, has high image quality, has high color development, has excellent offset resistance, and has excellent storage stability. Is to provide the body. Another object of the present invention is to
An object of the present invention is to provide an image forming method capable of forming a high-quality, high-colored, glossy image without deteriorating the image quality due to offset and deteriorating the transfer target.

[0018]

Means for Solving the Problems The inventors of the present invention have considered that the releasability of the transfer object is not limited to the effect of the release by the wax or oil at the interface between the transfer object and the fixing device. Paying attention to the release effect due to viscoelasticity at the time of layer deformation
As a result of intensive studies, it was found that 1 × 10 ⁵ to 1 × 10
^The present inventors have found that the use of a resin having a viscoelastic property with a higher elastic modulus of ⁶ Pa can control the release property of the transfer-receiving body, and have accomplished the present invention.

That is, the electrophotographic transfer member of the present invention has 10
An image receiving layer made of a thermoplastic resin is provided on at least one side of a substrate having a heat resistance of 0 ° C. or higher, and the thermoplastic resin has a glass transition temperature (Tg) and a loss elastic modulus (G ″) of G ″ = 1.
A minimum of tan δ of the binder resin exists between the temperatures at which the binder resin reaches × 10 ⁴ Pa, the minimum value of tan δ is less than 1.2, and the storage elastic modulus (G ′) at the temperature at the minimum of tan δ. ) Is G ′ = 5 × 10 ⁵ Pa or more, and G ″ = 1 × 10 ⁴
The resin is characterized by having a value of tan δ at a temperature of Pa of 1.0 or more.

The thermoplastic resin constituting the image receiving layer preferably contains a linear polyester resin having no cross-linked structure in the molecule.

As long as the thermoplastic resin satisfies the above-mentioned specification of the physical properties of the viscoelastic properties, even if only one kind is used,
Although two or more kinds may be used in combination, when two or more kinds are used in combination, it is necessary that the physical property value of the mixture is in the above range. As a preferable resin combination, at least one resin (A) of the two resins (A, B) is used.
However, when the Tg is in the range of 45 to 65 ° C. and the temperature is from Tg to G ″ = 1 × 10 ⁴ Pa, there is a minimum value of tan δ of the resin, and the minimum value of tan δ is less than 1.0. The value of tan δ at a temperature at which G ″ = 1 × 10 ⁴ Pa is 1.0 or more, and the Tg of the resin (A) used in combination is Tg + 5 ° C. to Tg + 15 ° C. of the resin (B).
And a minimum of tan δ of the resin exists between Tg and G ″ = 1 × 10 ⁴ Pa, the minimum value of tan δ is 1.0 or more, and G ″ = One having a tan δ value of 3.0 or more at a temperature of 1 × 10 ⁴ Pa is exemplified.

In the image forming method of the present invention, a step of forming a latent image on a latent image carrier, a step of developing the latent image using an electrophotographic developer, and a step of depositing the developed toner image on a transfer-receiving member In an image forming method including a transferring step and a fixing step of heating and pressing a toner image on a transfer object, the electrophotographic transfer object of the present invention is used as the transfer object.

It is more preferable that the image receiving layer contains a release agent.

The fixing step of the image forming method of the present invention is preferably carried out by using a contact-type heat fixing device containing a fluorine resin on the surface of the fixing member. More preferably, it is performed using an apparatus.

In the present invention, when the amount of oil applied to the fixing device is 8.0 × 10 ⁻⁴ mg / cm ² or less, the amount of oil applied is the same as that for fixing black and white toner, or the same amount of oil is applied for fixing black and white toner. It is referred to as a mold coating amount.

[0026]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is an explanatory diagram of viscoelastic characteristic values defined as physical properties of a resin used for forming an image receiving layer of a transfer object in the present invention. G ′ is the storage modulus (in FIG. 1,
G "represents a loss elastic modulus (represented by a dashed line graph in FIG. 1), and tan δ (tan Delt
a: loss tangent, represented by the solid line graph in FIG. 1) is tan
δ = G "/ G '. These values are obtained from dynamic viscoelasticity measurements. Briefly, the elastic response of the modulus of elasticity in relation to the stress that occurs during deformation and strain. The component is G ', and the energy for the deformation work at this time is stored. The viscous response component of the elastic modulus is G ",
The energy for the deformation work at this time is lost as heat. tan δ (= G ″ / G ′) is their ratio and is a measure of the degree of energy loss and storage for deformation work.

The resin used for forming the image receiving layer of the transfer-receiving member of the present invention may have a tan at a temperature from Tg to G ″ = 1 × 10 ⁴ Pa.
A minimum of δ exists, the minimum value of tan δ is less than 1.2, and G ′ at the minimum temperature of tan δ is 5 × 10
Tan δ at a temperature of ⁵ Pa or more and G "= 1 × 10 ⁴ Pa
Has a viscoelastic property of 1.0 or more. In other words, in the middle stage of the fixing process, when the resin of the image receiving layer is in a molten state between the nips, the viscoelastic properties exhibit high viscosity characteristics, and at the time of peeling at the final stage, the resin of the image receiving layer becomes It represents a characteristic having a high elastic modulus and an elastic characteristic superior to or comparable to the viscosity characteristic. That is, by setting the viscosity in the viscoelastic range, the toner image becomes viscous in the fixing nip, and the edge portion of the toner image is embedded in the image receiving layer. By embedding the edge portion of the toner image in the image receiving layer, the projected image of the halftone image portion can be clearly colored.

The viscoelastic characteristic value in the present invention is measured at a frequency of 1 rad / sec, 20% or less using a parallel plate having a diameter of 8 mm using a rotating plate type rheometer (RDA2, RHIOS system ver. 4.3). The distortion of about
The temperature was measured at a temperature rise rate of 10 ° C./min. Between 40 and 150 ° C. at a sample weight of about 0.3 g, and the measured value was obtained.

Since the resin used for forming the image receiving layer of the present invention satisfies the viscoelastic properties described above, the image receiving layer can be regarded as a hard resin plate at the time of peeling. Even when the toner is fixed, the release of the toner becomes good, and a clear color developing property can be obtained. The reason will be described below.

Normally, the nip time for heat roll fixing is usually 20
100100 msec, and the corresponding measurement frequency of the dynamic viscoelasticity measurement is about 10 to 100 rad / sec. Since the delamination occurs instantaneously, the measurement frequency corresponding to the delamination will be one or two orders of magnitude higher than the measurement frequency corresponding to the nip time. Since it is known that the fixing of the toner is performed at a viscosity of about 1000 Pa.s, the elastic modulus corresponding to the peeling deformation is 1 × 10 ⁵
It is about Pa. Therefore, it is presumed that the viscoelastic property at an elastic modulus during the transition from the glassy state to 1 × 10 ⁴ Pa is effective for the peeling deformation.

In the viscoelastic properties relating to the peeling deformation, by setting the minimum of the tan δ to less than 1.2, when the polymer chain is subjected to the peeling deformation, the storage elastic modulus G ′ is obtained.
Is greater than or equal to the loss modulus G ", that is, it is elastic like rubber and has a small energy loss, and has a sufficient thickness in view of the molecular size of the polymer. A state is obtained in which force can be transmitted from the polymer chains in the image receiving layer to the polymer chains, and even to the polymer chains existing at the interface between the image receiving layer and the fixing device without a gap between the polymer molecules, and at the same time, G ′ at that time is obtained. By setting the pressure to 5 × 10 ⁵ Pa or more, the rubber state becomes a rubber having a high elastic modulus, so that it is possible to prevent wrapping deformation and improve the toner release.

Simultaneously satisfying the above-mentioned two viscoelastic properties is a necessary condition for obtaining the effective releasability in the present invention. Even if the minimum of tan δ is 1.2 or more, or the G ′ at the minimum temperature of tan δ is less than 5 × 10 ⁵ Pa, in any case, winding occurs, and sufficient release is performed. I can not get the nature. In order to obtain releasability, more preferably, G ′ at the temperature at the minimum of tan δ is 6 × 10 ⁵ Pa or more, and further preferably, G ′ is
7 × 10 ⁵ Pa or more. The minimum value of tan δ is preferably 1.1 or less, and more preferably 1.0 or less, since a smaller value of tan δ is advantageous for peeling. Although there is no lower limit from the point of peeling, the minimum value of tan δ is preferably 0.3 or more from the viewpoint of coating productivity such as solubility in a solvent.

Further, the resin used for forming the image receiving layer of the transfer-receiving member of the present invention has a tan δ at a temperature at which G ″ = 1 × 10 ⁴ Pa.
Is required to have a viscoelastic property of 1.0 or more. This is a necessary condition for sufficiently burying the toner image in the image receiving layer at the time of fixing. By satisfying this condition, the obtained toner image becomes a clear color image even as an OHP projection image. . If the value of tan δ is less than 1.0, the amount of toner buried in the image receiving layer decreases, and in particular, the color developability of a halftone image decreases. For the above reasons, tan δ at a temperature where G ″ is 1 × 10 ⁴ Pa is preferably 2.0 or more, and
More preferably, it is 0 or more.

The temperature at which G ″ indicates 1 × 10 ⁴ Pa is 180 ° C.
C. or lower is preferable in terms of lowering the fixing temperature.

The glass transition temperature (Tg) of the resin used for forming the image receiving layer of the transfer object of the present invention is preferably in the range of 45 to 85 ° C, more preferably in the range of 50 to 75 ° C. More preferably, it is in the range of 55 to 70 ° C.
If the Tg is lower than 45 ° C., the heat storage property of the transferred body is not sufficient, and if the Tg is higher than 85 ° C., the fixing temperature becomes too high.

The glass transition temperature (Tg) of the resin can be determined by a conventional method using, for example, a differential scanning calorimeter (manufactured by Mac Science: D
SC3110, thermal analysis system 001: hereinafter, abbreviated as “DSC”), at a heating rate of 5 ° C./min, and on the low-temperature side of the endothermic point corresponding to Tg in the obtained chart. The shoulder temperature can be Tg. In the present invention
Tg is measured as described above.

Next, the resin satisfying the viscoelastic properties suitable for the transfer object of the present invention will be specifically described.

For example, a styrene-acrylic resin widely used in the past has a narrow molecular weight distribution (Mw / Mn =
3) In the case of a resin having a high molecular weight (Mw = 100,000), tan
The viscoelastic property at temperature at the minimum of δ is G '= 1.1 × 10 ⁵ Pa
, Tan δ = 0.9. Further, even with the same styrene-acrylic resin composition, it contains a low molecular weight component and a high molecular weight component, which are widely used in conventional black and white toners (Mw / Mn =
50) For higher molecular weight (Mw = 200,000) resins,
The viscoelastic property at temperature at the minimum of tan δ is G '= 1 × 10
⁴ Pa, tan δ = 0.67. That is, it can be understood that simply including a high molecular weight component or increasing the average molecular weight can reduce the minimum of tan δ, but G 'at the temperature at the minimum of tan δ cannot satisfy the range of the present invention. This tendency is generally observed in styrene-based resins having good adhesiveness, and none of them is suitable for forming an image receiving layer of the transfer-receiving body of the present invention.

The resin used for forming the image receiving layer of the transfer-receiving member of the present invention includes polyamide resin, polycarbonate resin, polyether resin and polyacrylonitrile from the viewpoint that the storage elastic modulus G 'at the temperature at the minimum of tan δ is large. Resins, polyarylate resins, and polyester resins are preferred. Above all, from the viewpoint of the melting temperature range, the glass transition temperature, and the resin strength, the resin composition used for forming the image receiving layer of the transfer object of the present invention is preferably a polyester resin as a main component.

The polyester resin is not particularly limited as long as it satisfies the viscoelastic properties according to the present invention.
A polyester resin having no F-insoluble component is preferred. Generally, a general-purpose polyester resin having a cross-linked structure in a molecule has a lower tan δ than a linear resin at a temperature of a minimum.
Since G ′ tends to be low, a linear polyester resin is particularly preferable among the polyester resins.

Hereinafter, preferred polyester composition and molecular weight will be described in detail. As a polyester composition that satisfies the viscoelastic properties, which is suitable as a resin used for forming the image receiving layer of the transfer receiving body of the present invention, the storage elastic modulus (G ′) at a temperature at least at the minimum of tan δ tends to be large. Those are preferred, and from that viewpoint, as the dicarboxylic acid component, specifically, terephthalic acid, isophthalic acid, cyclohexanedicarboxylic acid, naphthalene-2,6-dicarboxylic acid, naphthalene-2,7-dicarboxylic acid and the like Naphthalenedicarboxylic acid and biphenyldicarboxylic acid are preferred. Examples of the diol component include ethylene glycol, propylene glycol, neopentyl glycol, cyclohexanedimethanol, cyclohexanediol, and ethylene oxide adduct of bisphenol A represented by the following formula (in the following formula). Compound A) of bisphenol A It is preferable to use any one of trimethylene oxide adducts (compound B in the following formula) or a mixture mainly composed of a plurality thereof.

[0042]

Embedded image

(Wherein m and n are each independently 2 to 7
Indicates an integer. For example, the propylene oxide adduct of bisphenol A (compound C in the above formula) is a diol component conventionally used in polyester resins for toners. In comparison, G ′ at the temperature at the minimum of the tan δ becomes smaller. Similarly, even when a general-purpose orthophthalic acid is used as the dicarboxylic acid, G ′ at the temperature at the minimum of the tan δ is used.
Becomes smaller. Therefore, in the present invention, it is not preferable to use these diols and dicarboxylic acids as the main components.

A general-purpose polyester resin having a cross-linked structure in the molecule, which is known as a binder resin for a toner, tends to have a lower G ′ at a temperature at a minimum tan δ than a linear resin, It is not preferable for the resin for forming the image receiving layer of the transfer object of the present invention. This is presumed to be because the molecular chain having a cross-linked structure has a smaller spread of the chain, and the effect of transmitting the deformation is weaker than that of a linear molecular chain.

Accordingly, as carboxylic acids and diols,
It is also not preferable to use a monomer having a trivalent or more crosslinked structure as a main component. However, as long as the viscoelastic properties of the present invention are satisfied, even if a trivalent or higher polycarboxylic acid or a trivalent or higher polyhydric alcohol is used in an extremely small amount (about less than 5 mol%) for improvement of other physical properties. I do not care.

The molecular weight for obtaining the viscoelastic properties suitable for the present invention is, for example, a number average molecular weight Mn of 5,000 to 10,000, a weight average molecular weight Mw of 13,000 to 25,000, and a z average molecular weight Mz of 20,000.
770,000 and Mw / Mn is 3-5.

The molecular weight and the molecular weight distribution can be measured by known methods, but are generally measured by gel permeation chromatography (hereinafter abbreviated as “GPC”). GPC measurement is, for example, GPC
HLC-802A manufactured by TOYO SODA as the device, oven temperature 40 ° C, column flow rate 1 ml per minute, sample injection volume 0.1 ml
The concentration of the sample is 0.5%, and the measurement can be performed using THF for GPC manufactured by Wako Pure Chemical Industries, Ltd.
The calibration curve can be prepared, for example, using a standard polystyrene sample manufactured by TOYO SODA. In the present invention, the molecular weight and the molecular weight distribution are measured as described above.

As long as the viscoelastic properties of the present invention are satisfied, the following monomers can be used in addition to the above-mentioned preferred monomers.

Examples of the divalent carboxylic acid include succinic acid, glutaric acid, adipic acid, speric acid, azelaic acid, sebacic acid, phthalic acid, isophthalic acid, terephthalic acid, naphthalene-2,6-dicarboxylic acid and naphthalene -2,7
-Dibasic acids such as dicarboxylic acid, cyclohexanedicarboxylic acid, malonic acid, and mesaconic acid; and their unsaturated anhydrides and lower alkyl esters thereof; and aliphatic unsaturated dicarboxylic acids such as maleic acid, fumaric acid, itaconic acid, and citraconic acid. And the like. Examples of the trivalent or higher carboxylic acid that can be used together in a trace amount include, for example, 1,2,4-benzenetricarboxylic acid, 1,2,5-benzenetricarboxylic acid,
Examples thereof include 1,2,4-naphthalenetricarboxylic acid and the like, and anhydrides and lower alkyl esters thereof.
These may be used alone or in combination of two or more.

Examples of the dihydric alcohol include bisphenol A, hydrogenated bisphenol A, ethylene oxide or (and) propylene oxide adduct of bisphenol A, 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol, and ethylene glycol. , Diethylene glycol, propylene glycol, dipropylene glycol, 1,3-butanediol, 1,4-butanediol,
Examples thereof include 1,5-pentanediol, 1,6-hexanediol, and neopentyl glycol. Examples of trihydric or higher alcohols that can be used together in a trace amount include, for example,
Glycerin, trimethylolethane, trimethylolpropane, pentaerythritol and the like can be mentioned. These may be used alone or in combination of two or more.

If necessary, a monovalent acid such as acetic acid or benzoic acid, or a monohydric alcohol such as cyclohexanol or benzyl alcohol may be used for the purpose of preparing an acid value or a hydroxyl value. it can.

As the polyester resin, a suitable one is selected and combined from these monomer components.
Polycondensation (Chemical Doujin), Polymer Experiments (Polycondensation and polyaddition:
It can be synthesized using a conventionally known method described in Kyoritsu Shuppan) or a polyester resin handbook (edited by Nikkan Kogyo Shimbun), and specifically, a transesterification method, a direct polycondensation method, or the like, alone or in combination. Can be used.
In particular, in order to synthesize a linear polyester having a high degree of polymerization suitable for the present invention, it is necessary to increase the purity of the monomer, increase the degree of vacuum to remove reaction by-products, optimize the reaction temperature, and use a reaction catalyst. It is necessary to pay attention to synthesis conditions such as optimization. Further, the degree of polymerization of a polyester resin having a low degree of polymerization can be increased by using a diisocyanate-containing compound or the like. Among these, it is preferable to use a linear polyester resin containing a polyester resin obtained by polymerization by a transesterification method. In the case of the direct polycondensation reaction, it is extremely difficult to obtain a polyester having a high degree of polymerization due to a decrease in the purity of the monomer or a slight deviation from the optimum value of the charged amount of the monomer. This is because a linear polyester resin having a uniform molecular weight can be easily obtained.

In the transesterification method, a monomer having volatility under transesterification reaction temperature and reduced pressure (substantially vacuum state),
For example, at least one monomer having a boiling point of about 250 ° C. or less under reduced pressure, such as ethylene glycol or neopentyl glycol, is used as a first step, and the first step is performed at 150 ° C. to 280 ° C.
After carrying out the esterification reaction between the acid component and the alcohol component at about the temperature, the second stage is from 180 ° C to 380 ° C.
This is a synthesis method in which the degree of polymerization is increased by performing transesterification while removing volatile monomers to the outside of the system at a temperature and under reduced pressure at about the same temperature. Since it can be discharged, there is no decrease in the molecular weight due to a shift in the monomer ratio between the acid and the alcohol, so that a polyester having a high degree of polymerization can be synthesized easily and with a narrow molecular weight distribution. It is effective when combining.

The polyester resin synthesized by this method has a hydroxyl group at the terminal. When the polyester resin is used for forming an image receiving layer of a transfer-receiving member, a part or all of the hydroxyl group at the terminal is replaced with benzoic acid, trimellitic anhydride. It is also possible to modify with an acid, various acid chlorides or the like to impart an acid value and adjust the chargeability and adhesiveness.

More preferably, the resin composition for forming the image receiving layer of the transfer-receiving member of the present invention comprises at least two kinds of resins (A, B)
Wherein at least one resin (A) has a Tg of 45 ° C. to 65 ° C.
° C and between Tg and G "= 1 x 10 ⁴ Pa
There is a minimum of tan δ of the resin, and the minimum value of tan δ is less than 1.0 and t at a temperature at which G ″ = 1 × 10 ⁴ Pa
Resin (B) having an δ value of 1.0 or more and used in combination
Tg of the resin (A) is in the range of Tg + 5 ° C. to Tg + 15 ° C.,
During the temperature from Tg to G ″ = 1 × 10 ⁴ Pa, t
There is a minimum of an δ, and the minimum value of tan δ is 1.0
The value of tan δ at the temperature where G ″ = 1 × 10 ⁴ Pa of the resin (B) is not less than 3.0, and the resin as a whole is a blend resin satisfying the above viscoelastic properties. is there.

As described above, it is preferable to use two or more resins in combination from the viewpoint of setting the fixing temperature to a lower temperature and the viewpoint of improving the heat blocking property. As shown in FIG. 2, in the resin satisfying the viscoelastic properties of the present invention, the temperature dependence of the energy required for peeling has a peak near Tg, and the energy required for peeling increases with increasing temperature. Is reduced and peeling is facilitated. Also,
When the molecular weight increases, melting becomes difficult and the blocking resistance improves. For resins of the same composition, as the molecular weight increases
Due to the increase in Tg, those having a high molecular weight also have their decrease curves shifted to higher temperatures (shown by broken lines). Therefore, when increasing the molecular weight from the viewpoint of improving the heat blocking property, it is necessary to shift the fixing temperature to a higher temperature side in proportion to the increase in Tg. On the other hand, by using resins having different compositions and setting the Tg of the high molecular weight component lower than the Tg of the low molecular weight component, the blocking resistance can be maintained without increasing the fixing temperature. In FIG. 2, the peak of the peeling energy of the high molecular weight component is shifted,
At the fixing temperature set near Tg of the low molecular weight component, sufficient peeling can be achieved. On the other hand, when considering the low molecular weight component, the low molecular weight component in the resin has a disadvantageous effect on the blocking resistance.
By increasing the value, the anti-blocking property can be improved.

Therefore, as compared with the case where the viscoelastic property is satisfied with a one-component resin, the degree of freedom of the compounding composition is improved. A transfer medium that can be used at a lower fixing temperature can be easily obtained.

When polyester resins are blended and used, the composition and molecular weight of each polyester resin may be selected from the above-mentioned monomer group so as to obtain desired Tg and viscoelasticity.

If the heat-resistant temperature of the substrate to be transferred of the present invention is too low, the substrate will be deformed and wrapped around the fixing device during fixing, so the heat-resistant temperature must be 100 ° C. or higher. Specific examples of the substrate of the transfer object of the present invention include a polyethylene terephthalate film (hereinafter abbreviated as “PET”), a polyethylene naphthalate film (hereinafter abbreviated as “PEN”), and a polysulfone having a heat-resistant temperature of 100 ° C. or higher. Films, polyphenylene oxide films, polyimide films, polycarbonate films, cellulose ester films, polyamide films and the like can be used. Among them, PET and PEN are particularly preferred in terms of heat resistance and transparency. Although there is no particular upper limit to the heat resistance temperature in the range of use of electrophotography, it is desirable that the material melts at about 250 ° C. in consideration of moldability and reuse.

The transfer receiving body of the present invention can improve the color development of a light transmission image when an OHP film or the like using a transparent film as a substrate is used in that the toner can be embedded in the image receiving layer. Although particularly effective, the substrate is not limited to the plastic film. For example, paper or the like may be used. As the paper, plain paper such as “L paper” and “J paper” manufactured by Fuji Xerox Office Supply Co., Ltd., and recycled paper such as “R paper” and “WR paper” can be used.

The thickness of the substrate is preferably about 20 μm to 200 μm. If the substrate is thicker than 200 μm, the light transmittance deteriorates and the heat capacity at the time of fixing increases, so that it is necessary to raise the fixing temperature. On the other hand, if the substrate is thinner than 20 μm, the strength of the substrate material is insufficient due to the characteristics of the current substrate material, and the substrate itself is deformed due to the adhesive force between the toner and the fixing device. Become.

The image receiving layer can be formed by a conventionally known method. The image receiving layer may be provided on one side of the substrate,
It may be provided on both sides. In general, a method of dissolving a thermoplastic resin and other additives in a solvent, coating and drying with a spin coater or a bar coater, a method of applying an emulsion, heating and melting to smoothen, and the like. Can be
In order to improve the adhesiveness between the base and the image receiving layer, an adhesive layer may be provided, or the surface of the base may be subjected to a treatment such as a plasma treatment or a corona discharge. The coating thickness of the image receiving layer is 1 μ
It is preferably at least m and at most 20 μm. 1 image receiving layer
When the thickness is smaller than μm, the effect of improving the color developing property is small, and when the thickness is larger than 20 μm, the offset resistance decreases.

The image receiving layer may contain various conventionally known additives for further improving the performance.

For example, in order to improve the releasability, it is preferable to include a release agent. The release agent contained may be appropriately selected from the viewpoint of compatibility with the resin.Examples include paraffin wax such as low molecular weight polypropylene and low molecular weight polyethylene, silicone resin, rosins, rice wax, carnauba wax, and the like. Among them, those having a melting point of 40 ° C. to 150 ° C. are preferred, and those having a melting point of 70 ° C. to 110 ° C.
Are more preferred. If the content of the release agent is too large,
Although the releasability is advantageous, the light transmitting property is impaired or the adhesiveness between the substrate and the image receiving layer is reduced. Therefore, the content of the release agent is 7% by weight or less based on the resin of the image receiving layer, preferably It is more preferably at most 5% by weight, more preferably at most 3% by weight.

The release agent has a dispersion diameter of 1.0 μm in the image receiving layer.
The following makes it possible to further improve the light transmittance. If the release agent dissolves in the solvent, it may be applied as it is, but even if the release agent does not dissolve in the solvent, the release agent is preliminarily crushed to 0.5 μm or less, preferably 0.3 μm or less. Is dispersed in a solvent and applied and dried, whereby the dispersion diameter of the release agent in the image receiving layer can be reduced. Further, a method in which the resin of the image receiving layer and the release agent are kneaded in advance and then applied and dried can also be preferably used in order to reduce the dispersion diameter of the release agent in the image receiving layer. The drying at this time is preferably performed at a temperature equal to or lower than the melting point of the release agent from the viewpoint of preventing aggregation of the release agent.

In the image receiving layer, for controlling a friction coefficient,
Fine particles may be contained. As contained microparticles,
It is preferable that the difference in the refractive index from the resin of the image receiving layer is 0.2 or less. Specifically, inorganic fine particles such as silica, alumina and calcium carbonate, and organic fine particles such as polystyrene and polymethyl methacrylate can be used. Its content is preferably in the range of 0.1 to 10% by weight.

The transfer object of the present invention prevents image deterioration.
Surface resistance to 10 ⁷~Ten¹³Ω / cm^TwoNasu
Preferably. Surface resistance is 10¹³Ω / cm^TwoHigher,
Image deterioration due to discharge is likely to occur and the resistance is 10⁷Ω / c
m^TwoIf it is lower, the charge for holding the toner decreases
As a result, image degradation may occur. For this reason,
A charge control agent is applied to the image receiving layer to control triboelectric charging.
It can be contained. Or contains a charge control agent
Such a layer may be newly formed on the image receiving layer. Charging control
As the agent, a colorless and transparent agent is preferable.
Fonates, ammonium salts, sulfonium salts and gold
Metal oxide fine particles and the like can be used. These charging systems
If the dispersion of the agent is poor, the surface resistance will be biased and image deterioration will occur.
This is a factor.
Use a disperser such as Domill or Dynomill or apply ultrasonic waves.
Or add the image receiving layer binder and additives in advance.
Or extruder or Banbury mixer
It is preferable to improve the dispersibility by kneading with a solvent or the like.

The surface resistance was measured according to the method of JIS-K6911 according to the method of JIS-K6911. After the sample was left at 20 ° C. and 65% RH for 24 hours, a resistance measuring instrument “R8340 (manufactured by Advantest Co., Ltd.)” was used.
It can be measured at 100 volts.

The image forming method of the present invention is characterized by using the electrophotographic transfer member of the present invention. As a process of the image forming method of the present invention, a known image forming step, for example, a step of forming a latent image on a latent image carrier, a step of developing the latent image using an electrophotographic developer, What is necessary is just to employ | adopt what includes the process of transferring a toner image on a to-be-transferred body, the process of fixing the toner image on a to-be-transferred body, etc.

As a fixing device used in the image forming method of the present invention, a contact-type heat fixing device equipped with a known releasing agent applying means can be used. For example, a fixing device having a rubber elastic layer on a metal core,
A heating roller having a fixing member surface layer as necessary,
A heat roller fixing device having a rubber elastic layer on a core metal, and a pressure roller having a fixing member surface layer as necessary, and a combination of the roller and the roller, a combination of a roller and a belt, A fixing device instead of a combination of belts can be used.

For the rubber elastic layer, heat-resistant rubber such as silicon rubber or fluorine rubber is used.

As the fixing member surface layer, silicone rubber,
A layer made of a material having a low surface energy such as fluororubber, fluorolatex, fluororesin or the like is used. The transfer receiving body of the present invention has excellent releasability, so that when these fixing member surface layers are used, good reliability can be obtained. High fixing performance can be obtained.

As the fluororesin used on the surface of the fixing member, a soft fluororesin containing Teflon such as PFA (perfluoroalkoxyethyl ether copolymer), vinylidene fluoride or the like can be used. Compared with silicone rubber and fluorine rubber, fluororesin does not show a decrease in releasability due to adhesion or deposition of toner stains and the like, and is excellent in abrasion, so that the life of the fixing member can be extended.

For the base material (core) of the fixing member, a material having excellent heat resistance, high strength against deformation, and good heat conductivity is selected. In the case of a roll type fixing device, for example, aluminum, iron, or the like is used. , Copper, etc., and in the case of a belt-type fixing device, for example, a polyimide film, a stainless steel belt, or the like is selected.

The fixing member may contain various additives depending on the purpose. Examples thereof include carbon black, metal oxide, and SiC for the purpose of improving abrasion and controlling resistance.
And the like may be contained.

Referring to FIG. 3, the fixing step using the transfer object of the present invention will be described in detail. The thermocompression bonding apparatus shown in FIG.
A fixing member having a roller shape;
And a pressure roller 2 opposed thereto and a heat roller 1
And a release agent supply device 9 for supplying a release agent 15 to the fixing member surface layer 11 on the surface of the heat roller 1. An elastic layer 12 is provided on the surface of the heat roller 1.
Are formed. When the transfer member 14 on which the toner image 13 is formed passes between the pressure roller 2 and the heat roller 1, the transfer member 14 is heated and pressed to fix the image.

The thermocompression bonding apparatus shown in FIG. 3 further includes a cleaning member for removing toner adhering to the surface of the heat roller 1, a heating source 10 for heating the pressure roller 2, and a recording material, if necessary. A claw (finger) or the like for peeling off from the heat roller 1 may be provided. The heating source 10 in the thermocompression bonding apparatus shown in FIG. 3 is controlled by a temperature control device (not shown).

The heat roller 1 and / or the pressure roller 2 include
The elastic layer 12 preferably has a single-layer or laminated structure, and the thickness of the elastic layer is preferably 0.1 to 3 mm.
0.5 to 2 mm is more preferable. The elastic layer 12 is made of a heat-resistant rubber such as silicone rubber or fluorine rubber, and preferably has a rubber hardness of 60 or less. When the fixing member has the elastic layer 12, the fixing member is deformed following the unevenness of the toner image 13 on the transfer member 14, and is advantageous in that the smoothness of the image surface after fixing can be improved. is there. If the thickness of the elastic layer exceeds 3 mm and is too thick, the heat capacity of the fixing member increases, so that it takes a long time to heat the fixing member to a desired temperature and energy consumption is increased. Absent. The thickness of the elastic layer is 0.1m
If the thickness is less than m, the deformation of the fixing member cannot follow the unevenness of the toner image, causing uneven melting, and the elastic layer effective for peeling cannot be distorted.

In the image forming method of the present invention, the releasability
Because the transfer material has excellent surface energy,
When applying a fixing member having a surface layer made of a low material
In particular, apply a release agent to the fixing
No cloth is required, but the durability and release characteristics of the fixing member are improved.
From the above viewpoint, a release agent may be applied to the fixing member surface.
The release amount is the same as that of black and white toner
1.6 x 10 ^-Five~ 8.0 × 10^-Fourmg / cm^TwoIs preferred
No.

The coating amount of the release agent is preferably small from the viewpoint of the smoothness and gloss of the obtained image, but when the supply amount of the release agent is 0 mg / cm ² , It is practically preferable to supply a small amount of release agent to the fixing member because the amount of wear of the fixing member when the fixing member comes into contact with the transfer member may increase and the durability of the fixing member may decrease.

When the supply amount of the release agent is 8.0 × 10 ⁻⁴ mg / cm ² (A
(0.5 mg per sheet), the image quality deteriorates due to the release agent remaining on the image surface after fixing.
When the transmitted light such as P is used, the image quality is significantly reduced. In addition, there arises a problem that the release agent adheres to the transfer receiving body and stickiness occurs. Further, when the supply amount of the release agent is increased, the capacity of the tank for storing the release agent is also increased, and there is a problem that the size of the fixing device is increased.

The supply amount of the release agent is measured as follows. That is, when a plain paper (typically, a copy paper manufactured by Fuji Xerox Co., Ltd., trade name “J paper”) used in a general copying machine is passed through a fixing member having a releasing agent supplied to the surface thereof, the paper is printed on the plain paper. The release agent adheres to the surface. The release agent on the plain paper is extracted using a Soxhlet extractor. Hexane is used as the solvent. The release agent contained in the hexane is quantified by an atomic absorption spectrometer to determine the amount of the release agent attached to plain paper. This amount is defined as the amount of the release agent supplied to the fixing member.

The release agent used is not particularly limited, and examples thereof include liquid release agents such as heat-resistant oils, for example, modified oils such as dimethyl silicone oil, fluorine oil, fluorosilicone oil and amino-modified silicone oil. .

As the release agent, fluorine oil and fluorosilicone oil, which are high performance but expensive, can be used in the image forming method of the present invention. It can be used without any practical problems.

The method of supplying the release agent to the surface of the heat roller in the thermocompression bonding apparatus is not particularly limited. For example, a pad system impregnated with a liquid release agent, a web system, a roller system, or a non-contact shower system (Spray method) and the like. Among these, the web system and the roller system are preferable from the viewpoint that the release agent can be uniformly supplied and the supply amount can be easily controlled. In order to uniformly supply the release agent to the entire fixing member by a shower method, it is necessary to use a separate blade or the like.

When forming an image using the electrophotographic transfer member of the present invention, the toner used is not particularly limited, and various known toners can be used.

The G ″ of the thermoplastic resin forming the image receiving layer is 1
When the temperature indicating × 10 ⁴ Pa is Tf and the temperature at which the toner G ″ indicates 1 × 10 ⁴ Pa is Tt, the difference (Tf−Tt) between Tf and Tt is -30 to 30.
The temperature is preferably in the range of -20 ° C, and more preferably in the range of -20 to 20 ° C. If the difference is larger than this, the viscosities of the two at the time of melting are remarkably different, and the coloring property and the offset resistance may be impaired. Therefore, it is preferable to select the toner for the transfer target so as to satisfy this condition.

As the binder resin of the toner, polyester resin, styrene resin, acrylic resin, styrene-acrylic copolymer resin, epoxy resin, polyamide resin,
Polyurethane resin, silicone resin and the like,
From the viewpoint of controlling the toner characteristics, a polyester resin or a styrene-acrylic copolymer resin is preferably used. These can be used alone or in combination of two or more.

The colorant used in the toner of the present invention is not particularly limited, and includes known colorants.
It can be appropriately selected according to the purpose. Examples of the coloring agent include carbon black, lamp black, aniline blue, ultramarine blue, calcoil blue, methylene blue chloride, copper phthalocyanine, quinoline yellow, chrome yellow, Dupont oil red, orient oil red, rose bengal, and malachite green oxalate. Rate, Nigrosine Dye, CI Pigment Red 48: 1, CI Pigment Red 57: 1, CI
Pigment Red 81: 1, CI Pigment Red 122, C.I.
I. Pigment Yellow 97, CI Pigment Yellow 12,
CI Pigment Yellow 17, CI Pigment Blue 15:
1, CI Pigment Blue 15: 3 and the like.

The content of the colorant in the electrophotographic toner is preferably 1 to 30 parts by weight with respect to 100 parts by weight of the binder resin, but is preferably within a range not to impair the smoothness of the image surface after fixing. More is preferred. When the content of the colorant is increased, when obtaining an image of the same density,
This is advantageous in that the thickness of the image can be reduced, which is effective in preventing offset. Note that, depending on the type of the colorant, a yellow toner, a magenta toner, a cyan toner,
A black toner or the like can be prepared.

In the toner of the present invention, various known additives can be used in combination for the purpose of improving properties, as long as the effects of the present invention are not impaired. The additive component is not particularly limited and may be appropriately selected depending on the purpose. Examples thereof include various known additives such as inorganic fine particles, organic fine particles, a charge control agent, and a release agent.

Examples of the inorganic fine particles include silica, alumina, titanium oxide, barium titanate, magnesium titanate, calcium titanate, strontium titanate, zinc oxide, silica sand, clay, mica, wollastonite, diatomaceous earth, Bengala, cerium oxide, antimony trioxide,
Examples include magnesium oxide, zirconium oxide, silicon carbide, silicon nitride, calcium carbonate, calcium chloride, and the like. Among these, silica fine particles are preferable, and silica fine particles subjected to a hydrophobic treatment are particularly preferable. The inorganic fine particles are generally used for the purpose of improving fluidity. The primary particle diameter of the inorganic fine particles is 1 to 1000 nm
The amount is preferably 0.01 to 20 parts by weight based on 100 parts by weight of the toner.

The organic fine particles include, for example, polystyrene, polymethyl methacrylate, polyvinylidene fluoride and the like. The organic fine particles are generally used for the purpose of improving the cleaning property and the transfer property.

Examples of the charge control agent include salicylic acid metal salts, metal-containing azo compounds, nigrosine and quaternary ammonium salts. The charge control agent is generally used for the purpose of improving chargeability.

The transfer object of the present invention having such viscoelastic characteristics has good releasability of itself, and can be suitably used particularly without containing a release agent in the toner composition. However, for the purpose of increasing the offset temperature latitude and improving the cleaning property of the non-visual offset toner, it does not prevent inclusion of a trace amount of wax. It is rather preferable to add an appropriate amount of the release agent because the efficiency of the fixing process can be improved.

Examples of the release agent that can be used in the toner of the present invention include paraffin waxes such as low molecular weight polypropylene and low molecular weight polyethylene, silicone resins, rosins, rice wax, carnauba wax and the like. However, those having a temperature of 40 ° C to 150 ° C are preferable, and those having a temperature of 70 ° C to 110 ° C are more preferable. However, when the content of the release agent in the toner is too large, the release agent present on the surface or inside of the color-fixed image deteriorates the OHP projecting property; The release agent in the carrier migrates to the carrier and the charging performance of the developer changes over time; when used as a one-component developer, the release agent moves to the blade for charging by the friction between the toner and the blade. As a result, the charging performance of the developer changes with time; color image quality and reliability may be deteriorated, such as deterioration of the fluidity of the toner, and the content of the release agent is preferably 0.5 to 10%. More preferably 0.5 to 7%
And more preferably 0.5 to 5%.

The toner for electrophotography may be produced by any method. For example, a method for producing a dry toner is described in JP-A-5-127422, JP-A-7-152202 and the like. The kneading and pulverizing method, the kneading freezing and pulverizing method, and the wet toner production method include the in-liquid drying described in JP-A-63-25664, JP-A-63-282752, JP-A-6-250439, and the like. Production methods known per se, such as a method, a method in which a molten toner is subjected to shear stirring in an insoluble liquid to form fine particles, and a method in which a binder resin and a colorant are dispersed in a solvent and then subjected to jet spraying to form fine particles.

The electrophotographic toner used in the present invention may be a one-component electrophotographic developer or a two-component electrophotographic developer. In the case of a two-component type electrophotographic developer, the carrier used in combination with the toner is not particularly limited, and a known carrier, for example, a resin-coated carrier and the like are preferably exemplified. The resin-coated carrier is obtained by coating the surface of a core material with a resin, and examples of the core material include powders having magnetism such as iron powder, ferrite powder, and nickel powder. In addition, examples of the coating resin include a fluorine resin, a vinyl resin, and a silicone resin.

The electrophotographic developer of the present invention may contain additives and the like appropriately selected according to the purpose. For example, for the purpose of obtaining magnetism, iron, ferrite, irons including magnetite, nickel, metals exhibiting ferromagnetism such as cobalt, alloys or compounds containing these metals,
It may contain a magnetic material or a magnetizable material.

As described above, according to the transfer member for electrophotography of the present invention, since the tan δ value of the resin used for the image receiving layer is smaller than 1.2, the entanglement between the molecules is strongly present. The resin used for the image receiving layer shows elastic behavior due to the peeling strain at the time of fixing, can be sufficiently peeled off, and the image after fixing has high image quality and high color developing property,
The light transmittance was also excellent. Further, since the resin itself of the image receiving layer has excellent releasability, the amount of the release agent used in the fixing device can be significantly reduced, and the cut and stretchability of the copy is excellent, and the brushability is excellent. In addition, reduction in stickiness after fixing and downsizing of the fixing device can be realized. In addition, since the minimum value of tan δ of the resin used in the image receiving layer is smaller than 1.0, that is, since the resin strength is strong, the effect of improving the image strength after fixing and improving the storage stability of a copied product other than the releasability is also obtained. Can also be expected.

[0101]

EXAMPLES Examples of the present invention and comparative examples will be described below, but the present invention is not limited thereto.

(Synthesis Example 1 of Polyester Resin) Stirrer,
As shown in Table 1, 72.1 parts by weight of cyclohexane dimethanol and 67.9 parts by weight of terephthalic acid dimethyl ester were placed in a reaction vessel equipped with a thermometer, a condenser, and a nitrogen gas inlet tube.
Parts by weight, isophthalic acid dimethyl ester 87.3 parts by weight, cyclohexanedicarboxylic acid dimethyl ester 40.0
Parts by weight, and 1.0 part by weight of titanium tetrabutoxide as a catalyst, and the inside of the reaction vessel was replaced with dry nitrogen gas, and then heated in a mantle heater.
The reaction was stirred at 190 ° C. for about 5 hours. Thereafter, the mixture was cooled to room temperature, 124 parts by weight of ethylene glycol and 0.5 parts by weight of titanium tetrabutoxide were added, and the mixture was stirred and reacted at about 190 ° C. for about 5 hours under a nitrogen gas stream. The mixture was cooled to about 100 ° C while continuing stirring, and after confirming that no acid component monomer remained by silica thin layer chromatography (TLC), the pressure inside the reaction vessel was reduced to about 0.6 mmHg, and the temperature inside the reaction vessel was reduced. Raise to about 230 ° C at a rate of about 10 ° C / 5 minutes,
The mixture was reacted at 230 ° C. for about 2 hours to obtain a pale yellow transparent amorphous polyester resin A. Table 2 shows the physical property values of the amorphous polyester resin A.

(Synthesis Example 2 of Polyester Resin) As shown in Table 1, 72.1 parts by weight of cyclohexanedimethanol, 77.6 parts by weight of dimethyl terephthalate, and 87.3 parts by weight of dimethyl ester, 30.0 parts by weight of cyclohexanedicarboxylic acid dimethyl ester, and 1.0 part by weight of titanium tetrabutoxide as a catalyst, and after replacing the inside of the reaction vessel with dry nitrogen gas, heated in a mantle heater, The mixture was stirred and reacted at about 190 ° C. for about 5 hours under a nitrogen gas stream. Then, cool to room temperature,
124 parts by weight and 0.5 parts by weight of titanium tetrabutoxide were added, and the mixture was further stirred and reacted at about 190 ° C. for about 5 hours under a nitrogen gas stream. The mixture was cooled to about 100 ° C while stirring, and after confirming that no acid component monomer remained by silica thin layer chromatography (TLC), the pressure inside the reaction vessel was reduced to about 1.0 mmHg, and the temperature inside the reaction vessel was reduced. The temperature is raised to about 230 ° C at a rate of about 10 ° C / 5 minutes,
After reacting for hours, a colorless and transparent amorphous polyester resin B
I got Table 2 shows the physical property values of the amorphous polyester resin B.

(Synthesis Example 3 of Polyester Resin) Stirrer,
As shown in Table 1, 116.4 parts by weight of terephthalic acid dimethyl ester and isophthalic acid dimethyl ester were placed in a reaction vessel equipped with a thermometer, a condenser, and a nitrogen gas inlet tube.
77.6 parts by weight and bisphenol A ethylene oxide 2m
After adding 211.3 parts by weight of the adduct, 24.1 parts by weight of ethylene glycol, and 2.0 parts by weight of dibutyltin oxide as a catalyst, the inside of the reaction vessel was purged with dry nitrogen gas, and then dried at about 200 ° C. for about 5 hours under a nitrogen gas stream. The mixture was stirred for a period of time, and the temperature was further raised to about 240 ° C., and the mixture was stirred and reacted for about 5 hours to obtain a colorless and transparent amorphous polyester resin C. Table 2 shows the physical property values of the amorphous polyester resin C.

(Synthesis Example 4 of Polyester Resin) According to the composition ratio shown in Table 1, ethylene glycol was excessively added, and the pressure reduction degree and the reaction time were changed in the same manner as in Synthesis Examples 1 and 2 of the polyester resin. An amorphous polyester resin D was obtained. Table 2 shows the physical property values of the amorphous polyester resin D. (Synthesis Example 5 of Polyester Resin) According to the composition ratio shown in Table 1, in the same manner as in Synthesis Example 3 of polyester resin, the reaction time was changed to obtain amorphous polyester resin E. Table 2 shows the physical property values of the amorphous polyester resin E. (Synthesis Example 6 of Polyester Resin) According to the composition ratio shown in Table 1, an excess amount of ethylene glycol was added. Polyester resin F was obtained. Table 2 shows the physical property values of the amorphous polyester resin F.

(Synthesis Example 1 of Styrene-Acrylic Copolymer Resin) After the inside of the system was replaced with dry nitrogen gas in a reaction vessel,
780 parts by weight of tetrahydrofuran (hereinafter referred to as THF) from which water has been sufficiently removed as a solution, 265.2 parts by weight of styrene and 5 parts of n-butyl acrylate as monomers
7.6 parts by weight, and about 1 to the total number of moles of the monomer.
/ 100 mol of N, N'-azobisisobutyronitrile (hereinafter referred to as AIBN) was added, the system was heated to 60 ° C, and reacted at the same temperature for about 48 hours. After the reaction,
The solution was slowly dropped into about 7000 parts by weight of methanol while stirring, and the precipitate was filtered and dried to obtain a colorless and transparent amorphous styrene-acrylic copolymer resin G. Table 2 shows the physical property values of the amorphous styrene-acrylic copolymer resin G.

The following Table 1 shows the composition of the resins A to G used as the resin for the image receiving layer of the transfer object by the charged amount. The numerical values are the weight parts at the time of charging and the numerical values in parentheses. Represents the number of moles.

[0108]

[Table 1]

Table 2 shows resins A to G obtained in the above synthesis examples.
And the physical properties of the resin obtained by combining these two types. Hereinafter, each resin is represented by a resin number of (1) to (11). Among these, the resin numbers used in Examples and Comparative Examples are as follows.

Resin No. (2): Example 3 Resin No. (3): Comparative Example 2 Resin No. (4): Example 4 Resin No. (5): Comparative Example 3 Resin No. (6): Comparative Examples 4 and 6 Resin No. (7): Comparative Example 5 Resin No. (8): Example 1 Resin No. (9): Examples 2, 5, 6, 7 Resin No. (10): Example 8 Resin No. (11): Example 9

[0111]

[Table 2]

<Preparation of Evaluation Toner><Preparation of Polyester Toner A> 91 parts by weight of the amorphous polyester resin F obtained in Synthesis Example 6 of polyester,
Cyan pigment (Cyanine Blue 4933M: manufactured by Dainichi Seika Co., Ltd.)
4 parts by weight were melt-kneaded with a Banbury mixer-type kneader, and 7 minutes after the start of kneading, 5 parts by weight of purified carnauba wax (manufactured by Toagosei Co., Ltd.) was added, followed by melt-kneading for 8 minutes. The kneaded material is formed into a plate shape with a thickness of about 1 cm using a rolling roll, coarsely pulverized to about several millimeters with a Fitz mill type pulverizer, finely pulverized with an IDS type pulverizer, and classified sequentially with an elbow type classifier. I got The particle size distribution of the obtained toner was measured using a Coulter Counter TA-II type (manufactured by Coulter).
Was 8.8 μm. Toner was prepared by externally adding 3% by weight of hydrophobic silica powder (R972: manufactured by Nippon Aerosil Co., Ltd.) to this toner using a sample mill. The obtained toner is referred to as toner A.

<Preparation of Polyester Toner B> (B-1) Preparation of Pigment Dispersion 50 parts by weight of a polyester resin C and 50 parts by weight of a cyan pigment are dissolved and dispersed in 150 parts by weight of ethyl acetate. Was added to a sand mill disperser. While cooling around the dispersion vessel, 3
Time dispersed. While continuing stirring, an appropriate amount of ethyl acetate was added to prepare a pigment dispersion having a pigment concentration of 10% by weight.

(B-2) Preparation of Micronized Wax 10 parts by weight of wax previously ground in a mortar or the like is dispersed in 90 parts by weight of ethyl acetate, and this dispersion is subjected to a high-pressure emulsifying machine AP
Wax was atomized at a pressure of 500 kg / cm ² using a V GAULIN HOMOGENIZER 15MR type. The reaction was performed while appropriately adding ethyl acetate volatilized during the formation of fine particles. The obtained fine dispersion was micronized three times by the same process. When the particle size of the wax in the obtained fine dispersion was measured using a laser diffraction / scattering particle size distribution analyzer LA-700 (Horiba, Ltd.), it was about 0.7 μm. The dispersion liquid of the produced micronized wax was diluted with ethyl acetate so that the weight concentration of the wax became 10% by weight.

(B-3) Preparation of Oil Phase 87 parts by weight of the polyester resin F was dissolved in 200 parts by weight of ethyl acetate, and this solution was mixed with a pigment dispersion (resin concentration: 10%).
Weight%, pigment concentration 10% by weight) 40 parts by weight and micronized wax dispersion (wax concentration 10% by weight) 50 parts by weight,
Homo mixer (ace homogenizer, manufactured by Nippon Seiki)
And stirred at 15,000 rpm for 2 minutes to prepare a uniform oil phase.

(B-4) Preparation of aqueous phase 1 60 parts by weight of calcium carbonate (average particle size 0.03 μm) and 40 parts of pure water
The mixture was stirred for 4 days with a ball mill to prepare a calcium carbonate aqueous solution. The average particle size of calcium carbonate measured using the above-mentioned laser diffraction / scattering particle size distribution analyzer LA-700 (manufactured by Horiba Ltd.) was about 0.08 μm.

(B-5) Preparation of aqueous phase 2 2 parts by weight of carboxymethyl cellulose (Cellogen BSH; manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) was dissolved in 98 parts by weight of pure water to prepare an aqueous solution of carboxymethyl cellulose.

(B-6) Production Method of Toner An oil phase (B-3) (60 parts by weight) and a calcium carbonate aqueous solution (B
-4) 10 parts by weight and 30 parts by weight of an aqueous solution of carboxymethyl cellulose (B-5) were put into a colloid mill (manufactured by Nippon Seiki Co., Ltd.), and emulsified for 20 minutes at a gap interval of 1.5 mm and 8000 revolutions per minute. . Next, the above emulsion was put into a rotary evaporator, and the solvent was removed under reduced pressure of 30 mmHg at room temperature for 3 hours. Thereafter, 12N hydrochloric acid was added until the pH reached 2, and calcium carbonate was removed from the toner surface. Thereafter, 10N sodium hydroxide was added until the pH reached 10, and stirring was continued for one hour while stirring with an agitator in an ultrasonic cleaning tank. Further, centrifugal sedimentation was performed, and the supernatant was exchanged three times, washed, and dried to obtain a toner having a pigment content of 4% by weight and a wax content of 5%. Toner was prepared by adding 3% by weight of hydrophobic silica powder (R972, manufactured by Nippon Aerosil Co., Ltd.) to this toner. The obtained toner is referred to as toner B.

<Preparation of Styrene-Acrylic Copolymer Toner C> (C-1) Preparation of Resin Dispersion (1) Styrene 370 parts by weight, n-butyl acrylate 30 parts by weight, acrylic acid 8 parts by weight, dodecanethiol 24 parts by weight and 4 parts by weight of carbon tetrabromide are mixed and dissolved, and
6 parts by weight of a non-ionic surfactant (Nonipol 400, manufactured by Sanyo Chemical Co., Ltd.) and 10 parts by weight of an anionic surfactant (Neogen SC, manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.) were ion-exchanged with water.
In addition to the solution dissolved in 550 parts by weight,
Emulsified. To this emulsion, a solution obtained by dissolving 3.7 parts by weight of ammonium persulfate in 50 parts by weight of ion-exchanged water was added with slow stirring, and after purging with nitrogen, the content was brought to 70 ° C. while stirring the inside of the flask. Then, the mixture was heated in an oil bath until the emulsion polymerization was continued for 5 hours. As a result, a resin dispersion (1) having an average particle size of 140 nm, a glass transition point of 60 ° C., and a weight average molecular weight (Mw) of 32,000 was prepared.

(C-2) Preparation of Resin Dispersion (2) 280 parts by weight of styrene, 120 parts by weight of n-butyl acrylate, and 8 parts by weight of acrylic acid were mixed and dissolved.
6 parts by weight of a nonionic surfactant (Nonipol 400, manufactured by Sanyo Chemical Co., Ltd.) and 12 parts by weight of an anionic surfactant (Neogen SC, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) were ion-exchanged with water.
In addition to the solution dissolved in 550 parts by weight,
Emulsified. To this emulsion, a solution prepared by dissolving 3.6 parts by weight of ammonium persulfate in 50 parts by weight of ion-exchanged water was added with slow stirring, and after purging with nitrogen, the content was brought to 70 ° C. while stirring the inside of the flask. Then, the mixture was heated in an oil bath until the emulsion polymerization was continued for 5 hours. As a result, a resin dispersion (2) having an average particle size of 125 nm, a glass transition point of 52 ° C., and a weight average molecular weight (Mw) of 51,000 was prepared.

(C-3) Preparation of Colorant Dispersion (1) Phthalocyanine Pigment (PVSFASTBL manufactured by BASF)
UE) 100 parts by weight, 5 parts by weight of a nonionic surfactant (Nonipol 400, manufactured by Sanyo Chemical Co., Ltd.), and ion-exchanged water
200 parts by weight, mixed and dissolved, dispersed for 10 minutes using a rotor-stator type homogenizer, further dispersed for 5 minutes with an ultrasonic homogenizer, the average particle size is 150nm
A colorant dispersion liquid (1) obtained by dispersing the above colorant was prepared.

(C-4) Preparation of release agent dispersion liquid (1) Paraffin wax (HNP019 manufactured by Nippon Seiro Co., Ltd.)
0, melting point 85 ° C.) 50 parts by weight, a chaotic surfactant (Sanisol B50, manufactured by Kao Corporation) 5 parts by weight, ion-exchanged water
200 parts by weight are heated to 95 ° C., and a homogenizer (IKA
(Trade name: Ultra Turrax T50), and then subjected to a dispersion treatment using a pressure discharge type homogenizer to prepare a release agent dispersion liquid (1) obtained by dispersing a release agent having an average particle diameter of 550 nm.

(C-5) Preparation of Aggregated Particles Resin dispersion liquid (1) 120 parts by weight, resin dispersion liquid (2) 80 parts by weight, colorant dispersion liquid (1) 15 parts by weight, release agent dispersion 40 parts by weight of the liquid (1) and a cationic surfactant (Kao Corporation)
(Sanisol B50) (1.5 parts by weight) was placed in a round stainless steel flask, mixed and dispersed using a homogenizer (IKA: Ultra Turrax T50), and then stirred in a heating oil bath. While maintaining the temperature for 30 minutes. Thereafter, when the dispersion solution was observed with an optical microscope, it was confirmed that aggregated particles (volume: 95 cm ³ ) having an average particle size of about 5 μm were formed.

(C-6) Preparation of Adhered Particles The resin dispersion (1) 60 was added to the dispersion obtained in (C-5).
Parts by weight were added slowly. The resin dispersion (1)
Has a volume of 25 cm ³ . Further, the temperature of the heating oil bath was raised to 50 ° C. and maintained for one hour.
Thereafter, when the dispersion solution was observed with an optical microscope, it was confirmed that adhered particles having an average particle size of about 5.7 μm were formed.

(C-7) Preparation of toner After that, an anionic surfactant (Neogen SC, manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.) was added to the dispersion obtained in (C-6).
After the addition of parts by weight, the stainless steel flask was sealed, heated to 105 ° C. while stirring with a magnetic seal, and held for 3 hours. After cooling, the reaction product was filtered, and the collected matter was sufficiently washed with ion-exchanged water and dried to obtain an electrophotographic toner having an average particle diameter of 5.8 μm. When the surface condition was observed with an electron microscope, the exposure of the wax-like substance to the surface of the electrophotographic toner was slight, and no free wax-like substance was observed. Toner was prepared by adding 3% by weight of hydrophobic silica powder (R972, manufactured by Nippon Aerosil Co., Ltd.) to this toner. The obtained toner is referred to as toner C.

<Adjustment of Developer> Each of the obtained toners (A to
C) 7 parts by weight and 100 parts by weight of a carrier are mixed,
This was used as an electrophotographic developer. The carrier is a resin-coated carrier in which a ferrite core is coated with polymethyl methacrylate.

<Outline of Image Output Apparatus>
A device modified from A color 635 (manufactured by Fuji Xerox) was used. FIG. 4 schematically shows the image output device. This image output device includes a photoconductor 21, a charger 22, an exposure device 23,
Intermediate transfer member 24, four-color developing devices 25a, 25b, 25c,
25d, a general-purpose full-color image output device including a transfer charger 26 and a cleaner 27. The specific experimental conditions were as follows: an organic photoconductor (diameter: 84 mm) was used as the photoconductor 21;
LE400dpi as ROS, process speed 160mm / sec
The latent image potential is set to -550 V for the background portion and -150 V for the image portion, and the developing roll (common to the first to fourth developing devices) is fixed with a magnet.
Sleeve rotation, magnet magnetic flux density = 500G (on the sleeve), sleeve diameter = 25mm diameter, sleeve rotation speed = 300mm / s
ec, the distance between the photoreceptor 21 and the developing roll (common to the first to fourth developing devices) is 0.5 mm, and the distance between the developer layer layer thickness regulating member and the developing roll (common to the first to fourth developing devices) is 0.5 mm, and the developing bias (common to the first to fourth developing units) is DC component =-
An unfixed image was output using a 500 V, AC component = 1.5 kVP-P (8 kHz) and a transfer method using a corotron transfer method (wire diameter = 85 μm).

<Preparation of Unfixed Image> Using the above-described image output apparatus, a toner having a size of 50 mm × 50 mm and an image toner amount of 0.7 mg / cm ² was placed on each of the transfer receiving films of Examples and Comparative Examples. A solid image and a halftone image having a size of 50 mm × 50 mm and an image area ratio of 35% were produced.

<Evaluation of Toner Fixing Property> A silicon rubber layer having a thickness of 2 mm was coated on a metal core, and the surface layer was coated with 25 μm
Fixing unit consisting of a heat roll having an outer diameter of 50 mm having a PFA resin layer and a pressure roller having an outer diameter of 50 mm having a PFA resin layer of 25 μm coated on a metal core coated with a 1 mm thick silicon rubber layer. 6m nip width using
m and a fixing pressure of 6 kgf / cm ² . The conveyance speed of the fixing device was 55 mm per second. Further, the heat roll was provided with a peeling nail (finger) for peeling. The application of silicone oil to the fixing device is performed by attaching a silicone oil impregnated roll to a heat roll, and the application amount is controlled by a blade.
1 mg (1.7 × 10 ⁻⁴ mg / cm ² ). The silicone oil used was an A-color fuser oil. To measure the amount of silicone oil applied, pass white paper through the fuser, extract the oil with the oil adhering to it using a Soxhlet extractor using hexane as a solvent, and quantify the oil amount using an atomic absorption spectrometer. It has become.

Using the fixing device, an unfixed image of each toner is fixed by appropriately changing the temperature of the fixing device from 140 ° C. to 190 ° C., and the fixing property of the film to be transferred is determined by the hot fixing at a fixing device temperature of 165 ° C. Evaluation was made based on the presence or absence of offset generation, light transmittance, and hot offset generation temperature. For the light transmittance, the transmittance of the fixed image is measured using a spectrophotometer U-3210 (Hitachi, 480 nm wavelength).
It measured using. In addition, the transmittance | permeability measured the thing from which the highest gloss was obtained. The light transmittance of the film to be transferred is
When the light transmittance decreases, the transmitted light image tends to become intense without being sufficiently colored due to scattering on the toner surface. Therefore, the minimum condition is 70% or more.
% Is practically preferable. After fixing, the gloss of the image is determined by the gloss meter GM-26D (Murakami Color Research Laboratory Co., Ltd.)
And the incident light angle was set to 75 degrees. The occurrence of hot offset was determined based on whether or not deterioration such as waving occurred on the surface of the transferred film.

Example 1 6 parts by weight of the amorphous polyester resin A obtained in the synthesis example of the polyester resin, 14 parts by weight of the amorphous polyester B, and 1 part by weight of the alkyl phosphate surfactant were used. Was dissolved in 100 parts by weight of toluene, and the solution obtained was dissolved in 100 μm thick P using a bar coater.
Coated on ET film, dried and transferred film A
Was prepared. The viscoelastic characteristic values of the resin of the image receiving layer were the same as those of the resin number (8) in Table 2. An unfixed image was formed on the formed transfer film using toner A, and fixing evaluation was performed. Table 3 shows the results.

Example 2 The procedure of Example 1 was repeated except that 10 parts by weight of the amorphous polyester resin A and 10 parts by weight of the amorphous polyester B were used as the thermoplastic resin for forming the image receiving layer. A film to be transferred B was prepared by the above method and evaluated. The viscoelastic characteristic values of the resin of the image receiving layer were the same as those of the resin number (9) in Table 2. An unfixed image was formed on the formed transfer film using toner A, and fixing evaluation was performed. Table 3 shows the results.

Example 3 A film to be transferred C was prepared and evaluated in the same manner as in Example 1 except that 20 parts by weight of an amorphous polyester resin B was used as a thermoplastic resin for forming an image receiving layer. did. The viscoelastic characteristic values of the image receiving layer resin are shown in Table 2.
Of resin number (2). An unfixed image was formed on the formed transfer film using toner A, and fixing evaluation was performed. Table 3 shows the results.

Example 4 A film to be transferred D was prepared and evaluated in the same manner as in Example 1 except that 20 parts by weight of an amorphous polyester resin D was used as a thermoplastic resin for forming an image receiving layer. . The viscoelastic characteristic values of the image receiving layer resin were the same as those of the resin number (4) in Table 2. An unfixed image was formed on the formed transfer film using toner A, and fixing evaluation was performed. Table 3 shows the results.

Example 5 49 parts by weight of an amorphous polyester resin A and an amorphous polyester resin B 49
The transfer film E was prepared in the same manner as in Example 1, except that 2 parts by weight of the purified carnauba wax and 2 parts by weight of the purified carnauba wax were melted and kneaded in the same manner as in the method of preparing the toner A to obtain a resin for an image receiving layer. did. The viscoelastic characteristic values of the resin of the image receiving layer were the same as those of the resin number (9) in Table 2. An unfixed image was formed on the formed transfer film using toner A, and fixing evaluation was performed. Table 3 shows the results.

Example 6 49 parts by weight of an amorphous polyester resin A and an amorphous polyester resin B 49
The transfer film F was prepared in the same manner as in Example 1 except that 2 parts by weight of the purified carnauba wax and 2 parts by weight of the purified carnauba wax were melted and kneaded in the same manner as in the method of preparing the toner A to obtain a resin for the image receiving layer. did. The viscoelastic characteristic values of the resin of the image receiving layer were the same as those of the resin number (9) in Table 2. An unfixed image was formed using the toner B on the formed transfer film, and the fixing evaluation was performed. Table 3 shows the results.

Example 7 49 parts by weight of amorphous polyester resin A and 49 parts of amorphous polyester resin B
2 parts by weight of purified carnauba wax and 2 parts by weight of purified carnauba wax were melt-kneaded in the same manner as in the preparation method of toner A, and the same procedure as in Example 1 was carried out, except that the resin for the image receiving layer was used.
Was prepared. The viscoelastic characteristic value of the image receiving layer resin of the film G to be transferred was the same as the resin number (9) in Table 2. An unfixed image was formed on the formed transfer-receiving film using toner C, and fixing evaluation was performed. Table 3 shows the results.

(Example 8) As a thermoplastic resin for forming an image receiving layer, except that 8 parts by weight of an amorphous polyester resin A and 12 parts by weight of an amorphous polyester resin C were used.
A film H to be transferred was produced in the same manner as in Example 1. The viscoelastic characteristic value of the image receiving layer resin of the film to be transferred H was the same as the resin number (10) in Table 2. An unfixed image was formed on the formed transfer film using toner A, and fixing evaluation was performed. Table 3 shows the results.

(Example 9) As a thermoplastic resin for forming an image receiving layer, 6 parts by weight of an amorphous polyester resin A and 14 parts by weight of an amorphous polyester resin C were used.
A film to be transferred K was produced in the same manner as in Example 1. The viscoelastic characteristic values of the image receiving layer resin of the film to be transferred K were the same as those of the resin number (11) in Table 2. An unfixed image was formed on the formed transfer film using toner A, and fixing evaluation was performed. Table 3 shows the results.

(Comparative Example 1) A film having no image receiving layer formed on a PET film having a thickness of 100 µm was used for image evaluation as it was. To control the surface resistance, a solution obtained by dissolving 1 part by weight of an alkyl phosphate surfactant in 100 parts by weight of toluene is applied to a PET film using a bar coater, dried, and transferred. Film L was prepared. The surface electric resistance of the film L was 8.0 × 10 ¹⁰ Ω / cm ² . An unfixed image was formed on the formed transfer film using toner A, and fixing evaluation was performed. Table 3 shows the results.

Comparative Example 2 20 parts by weight of the amorphous polyester resin C obtained in the synthesis example of the polyester resin and 1 part by weight of the alkyl phosphate surfactant were dissolved in 100 parts by weight of toluene. The obtained solution was applied on a PET film using a bar coater, and dried to produce a film to be transferred M. Table 2 shows the viscoelastic properties of the resin in the image receiving layer.
Resin No. (3). An unfixed image was formed on the formed transfer film using toner A, and fixing evaluation was performed. Table 3 shows the results.

(Comparative Example 3) A transfer-receiving film N was prepared and evaluated in the same manner as in Comparative Example 2, except that 20 parts by weight of an amorphous polyester resin E was used as a thermoplastic resin for forming an image receiving layer. did. The viscoelastic characteristic values of the image receiving layer resin are shown in Table 2.
Resin No. (5). An unfixed image was formed on the formed transfer film using toner A, and fixing evaluation was performed. Table 3 shows the results.

(Comparative Example 4) A transfer film P was prepared and evaluated in the same manner as in Comparative Example 2, except that 20 parts by weight of an amorphous polyester resin F was used as the thermoplastic resin for forming the image receiving layer. did. The viscoelastic characteristic values of the image receiving layer resin are shown in Table 2.
Resin No. (6). An unfixed image was formed on the formed transfer film using toner A, and fixing evaluation was performed. Table 3 shows the results.

Comparative Example 5 A film to be transferred Q was prepared and evaluated in the same manner as in Comparative Example 2 except that 20 parts by weight of an amorphous polyester resin G was used as the thermoplastic resin for forming the image receiving layer. did. The viscoelastic characteristic values of the image receiving layer resin are shown in Table 2.
Resin No. (7). An unfixed image was formed on the formed transfer film using toner A, and fixing evaluation was performed. Table 3 shows the results.

Comparative Example 6 97 parts by weight of an amorphous polyester resin F and 3 parts by weight of purified carnauba wax were melt-kneaded in the same manner as in the preparation of toner A.
A solution obtained by dissolving 20 parts by weight of the obtained resin composition and 1 part by weight of an alkyl phosphate surfactant in 100 parts by weight of toluene was used in the same manner as in Example 1 using a bar coater. Then, it was applied on a PET film and dried to prepare a film to be transferred R. The viscoelastic characteristic value of the image receiving layer resin is
It was the same as resin number (6) in Table 2. An unfixed image was formed on the formed transfer film using toner A, and fixing evaluation was performed. Table 3 shows the results.

<Evaluation Results of Offset Resistance and Light Transmittance of Transferred Film> As can be seen from Table 3, each of the transferred films of Examples 1 to 9 of the present invention has a high offset generation temperature and a high light transmittance. Was also enough. In the transfer-receiving films of Examples 5 to 7 in which the wax was contained in the image-receiving layer, the light transmittance was slightly lowered as compared with the case where no wax was contained, but at a level where there was no problem in practical use. The offset property was remarkably improved. Regarding the image on the transfer film of the example, no image deterioration caused by fixing or transfer occurred. On the other hand, in each of the transferred films of Comparative Examples 2 to 5 in which the image receiving layer was formed of a resin not satisfying the range of the viscoelastic properties of the present invention, hot offset occurred at 140 ° C., and the transferred material was wound around a fixing roll,
The result was that it could not be peeled. It is considered that a sufficient stress could not be generated because the peeling deformation at the time of fixing was lost as heat. In the film of Comparative Example 6, although the image receiving layer itself was peeled off by the effect of the wax, it was out of the viscoelastic range of the present invention. The film could not be efficiently used for peeling, and the film wrapped around the fixing machine, resulting in offset. Further, in Comparative Example 1 in which the image receiving layer was not formed, the light transmittance satisfied the minimum condition, but the actual transmitted light image was a very gray strong cyan color. Observation of the fixed toner on the transfer film with an electron microscope reveals that each toner particle is present independently, and the cross-sectional shape of each toner is shaped like a half ellipse, which scatters light. It is considered that the coloring property was lowered. It should be noted that the light transmittance is a relatively high number,
This is probably because the amount of light that did not pass through the toner portion was large because the image area ratio of the toner was small.

[0147]

[Table 3]

<Evaluation of Full-Color Image Output> Amorphous polyester resin F 8 obtained in Synthesis Example 6 of polyester
9.5 parts by weight and 5.5 parts by weight of a cyan pigment (Cyanine Blue 4933M: manufactured by Dainichi Seika Co., Ltd.) are melt-kneaded by a Banbury mixer type kneader, and after 7 minutes from the start of kneading, purified carnauba wax (Toa Gosei Co., Ltd.) ) Was added and melt-kneaded for an additional 8 minutes. Roll the kneaded material to a thickness of 1c
m, and roughly ground to a few millimeters with a Fitz mill type pulverizer, finely pulverized with an IDS type pulverizer, and classified sequentially with an elbow type classifier to obtain a toner. The obtained toner was 8.8 μm. Similarly, the colorant is changed from a cyan pigment (Cyanine Blue 4933M: manufactured by Dainichi Seika Co., Ltd.) to a magenta pigment (Seika Fast Carmin 1476T-7; manufactured by Dainichi Seika Co., Ltd.) and a yellow pigment (Seika First Yellow 2400). A magenta toner, a black toner, and a yellow toner were produced in place of carbon black (Carbon Black # 25; manufactured by Mitsubishi Chemical Corporation), respectively, to obtain four full-color toners. Toner of each color was externally mixed with 3% by weight of hydrophobic silica powder (R972: manufactured by Nippon Aerosil Co., Ltd.) using a sample mill to prepare toner. Using this toner, a full-color image was output on the transfer-receiving film B at an image toner amount of 0.45 mg / cm ² using the image output device described above. Further, using the above-described fixing device, the paper conveyance speed was 50 mm / sec, and the fixing device temperature was 165 ° C.
As a result, image deterioration such as offset did not occur, and color development was sufficiently excellent.

The transfer member for electrophotography according to the present invention is suitable for forming an image with a color toner and forming a light transmission image, has oilless fixing suitability, and has high image quality and high color development. Also, it is excellent in offset resistance and storage stability. In addition, according to the image forming method of the present invention using the electrophotographic transfer object, a high-quality, high-colored, glossy image can be formed without deteriorating the image quality due to the offset and deteriorating the transfer object. can do.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of a viscoelastic characteristic value of a binder resin used for an electrophotographic toner of the present invention.

FIG. 2 is a conceptual diagram of the temperature dependence of the releasability of a binder resin used in the electrophotographic toner of the present invention.

FIG. 3 is a schematic configuration diagram illustrating an example of a heat fixing device used in the image forming method of the present invention.

FIG. 4 is a schematic configuration diagram showing an example of an image output device for explaining an image forming method of the present invention.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 heat fixing roller 2 pressure roller 9 release agent application device 10 heating source 11 fixing member surface layer 12 elastic layer 13 toner image (non-fixed image) 14 transfer target (recording material) 15 release agent 21 photoconductor (electrostatic) Latent image carrier 22 Charger 23 Exposure device 24 Intermediate transfer member 25 Four-color developing device (25a, 25b, 25c, 25d) 26 Transfer charger 27 Cleaner

Claims (7)

[Claims] An image receiving layer comprising a thermoplastic resin is provided on at least one side of a substrate having a heat resistance of 100 ° C. or higher, and the thermoplastic resin has a glass transition temperature (Tg) and a loss elastic modulus (G ″). ) Is G ″ = 1 × 10 ⁴ Pa, there is a minimum of tan δ of the binder resin, the minimum value of tan δ is less than 1.2, and the temperature at the temperature at the minimum of tan δ is The value of tan δ at the temperature where the storage elastic modulus (G ′) is G ′ = 5 × 10 ⁵ Pa or more and G ″ = 1 × 10 ⁴ Pa is 1.0
A transfer member for electrophotography, comprising the above resin. 2. The electrophotographic transfer object according to claim 1, wherein the thermoplastic resin contains a linear polyester resin having no cross-linked structure in the molecule. 3. The at least two kinds of thermoplastic resins
At least one resin (A)
However, Tg is at 45 to 65 ° C, and T "is G" = 1 x 10 ^FourTemperature to become Pa
In the meantime, there is a minimum of tan δ of the resin,
The minimum value of tan δ is less than 1.0, and G ″ = 1 × 10^FourPa
The value of tan δ at a certain temperature is 1.0 or more,
The Tg of the resin (A) to be obtained is Tg of the resin (B) + 5 ° C to Tg + 15 ° C
In the range of Tg to G "= 1 × 10^FourDuring the temperature that reaches Pa
Has a minimum of tan δ of the resin,
The minimum value is 1.0 or more, and G "= 1 × 10^FourBe Pa
The value of tan δ at temperature is 3.0 or more,
The electrophotographic transfer member according to claim 1 or 2, wherein 4. The transfer member for electrophotography according to claim 1, wherein the image receiving layer contains a release agent. 5. A step of forming a latent image on a latent image carrier, a step of developing the latent image using a developer for electrophotography, a step of transferring the developed toner image onto a transfer object, and a step of 5. An image forming method including a fixing step of heating and pressing a toner image on a transfer member, wherein the transfer member is an electrophotographic transfer member according to any one of claims 1 to 4. Image forming method. 6. The image forming method according to claim 5, wherein the fixing step is performed using a contact-type heat fixing device including a fluororesin on the surface of the fixing member. 7. The fixing step, wherein no oil is applied to the surface of the fixing member, or the fixing step is performed using a heat fixing device with an oil application amount of 8.0 × 10 ⁻⁴ mg / cm ² or less. The image forming method according to claim 5.