JP2001142245A - Electrophotographic transferable material and method for producing same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To produce an electrophotographic transferable material suitable for use in an indirect dry full-color electrophotographic process, excellent in image quality and excellent also in the durability of the transferable layer side. SOLUTION: The electrophotographic transferable material has a transferable layer on at least one face of the substrate and a middle layer comprising a polyester resin layer between the transferable layer and the substrate. The polyester resin preferably has <=65 deg.C glass transition temperature (Tg) and a molecular weight of >=15,000.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a material to be transferred for electrophotography and a method for producing the same. The present invention relates to an electrophotographic transfer material having excellent durability and a method for producing the same.

[0002]

2. Description of the Related Art As an indirect dry full-color electrophotographic system, (1) a multiple transfer system for sequentially transferring four color toners;
(2) An electrostatic latent image corresponding to each color sequentially formed on the image carrier is sequentially developed with each color toner, and the developed image is electrostatically sequentially superimposed on a belt-shaped intermediate transfer body to perform primary transfer. At the same time, the toner image multi-transferred onto the intermediate transfer member is secondarily transferred to a transfer-receiving material by a bias transfer roll to which a transfer voltage having a polarity opposite to the charging polarity of the toner is applied, thereby forming a color image. The method of forming (hereinafter referred to as
(Referred to as an intermediate transfer member system), (3) a process of visualizing by a plurality of developing devices is performed a plurality of times to form a multicolor image on an image carrier, and the multicolor image is collectively transferred to a material to be transferred. A method of forming a color image, (4) a plurality of image carriers are juxtaposed, and the images formed on each image carrier are conveyed to a transfer belt;
2. Description of the Related Art A method of forming a color image by sequentially transferring images to a transfer-receiving material has been conventionally known.

[0003] Among these electrophotographic systems, (2)
The intermediate transfer type is a retention type in which a high-quality recorded image can be obtained, and a latent image formed once is used multiple times by repeating development and transfer to record many identical images. This is advantageous in that the speed of image recording can be easily increased. For this reason, in recent years, (2) the development of the intermediate transfer member system has been actively promoted.

Conventionally, as a transfer material for electrophotography,
(A) Transfer receiving material having a transfer receiving layer provided on a support of base paper alone; (B) Transfer receiving material having a transfer receiving layer provided on one side of cast coated paper having a cashicoat layer on one side of the base paper; The full-color electrophotographic transfer material used in the electrophotographic method such as the above-mentioned intermediate transfer method includes (C) a transfer paper layer on one side of a support having a coating layer made of a resin such as polyethylene on both sides of a base paper. Transfer material provided with (D)
Transfer receiving material provided with a transfer receiving layer on one side of a film base,
Etc. Further, the above-mentioned transferred layer has been obtained, for example, by forming a dry film using a solution obtained by dissolving a polyester-based copolymer in an organic solvent.

[0005] However, these electrophotographic materials to be transferred, although having a certain image quality, have problems such as uneven gloss after printing and cracks on the layer to be transferred, resulting in durability problems.

[0006]

SUMMARY OF THE INVENTION It is a first object of the present invention to provide an image having particularly excellent image quality, not to cause uneven gloss after printing, and to reduce or eliminate cracks and the like on the layer to be transferred.
It is to provide an electrophotographic material to be transferred as possible. A second object of the present invention is to provide a method for producing an electrophotographic transfer material which can easily produce an electrophotographic transfer material having the above-mentioned characteristics.

[0007]

SUMMARY OF THE INVENTION The first object described above is intended to provide:
An electrophotographic transfer material having a transfer layer on at least one surface of a support, wherein an intermediate layer made of a polyester resin layer is provided between the transfer layer and the support. This is achieved by an electrophotographic transfer material. As the polyester resin constituting the intermediate layer,
Glass transition temperature (Tg) of 65 ° C or less and molecular weight of 15
A polyester resin of 000 or more is preferred. The second object is a method for producing an electrophotographic transfer material in which an intermediate layer and a transfer layer are provided in this order on a support, and the transfer layer and the intermediate layer are formed on the support. This is achieved by a method for producing an electrophotographic transfer material, which is formed by a melt coextrusion method.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described. The support in the present invention includes a support made of base paper, or a support having a resin coating layer on one or both sides of the base paper. -Base paper-As the base paper, it is preferable to use natural pulp such as softwood or hardwood as a main raw material. If desired, fillers such as clay, talc, calcium carbonate, urea resin fine particles and the like, sizing agents such as rosin, alkyl ketene dimer, higher fatty acid, epoxidized fatty acid amide, paraffin wax, alkenyl succinic acid, starch, polyamide polyamine epichlorohydrin, A paper strength enhancer such as polyacrylamide and a fixing agent such as a sulfate band and a cationic polymer can be added to the pulp. In particular, it is preferable to add an epoxidized fatty acid amide or an alkyl ketene dimer because the adhesion between the base paper and the coating layer can be improved by flame treatment of the base paper.

The content of the epoxidized fatty acid amide and alkyl ketene dimer is 0.0
It is preferably from 5 to 2.0% by weight, particularly preferably from 0.1 to 1.0% by weight.

Furthermore, synthetic pulp may be used in place of the above-mentioned natural pulp, or pulp obtained by mixing natural pulp and synthetic pulp in an arbitrary ratio may be used.

Although the type and thickness of the base paper are not particularly limited, the basis weight is 50 g / m ^{2 to} 250 g / m ² .
m ² is preferred. Further, since the base paper desirably has excellent surface smoothness as a material to be transferred for electrophotography, it is preferable that the base paper is subjected to surface treatment by applying heat and pressure using a machine calender, a super calender, or the like.

The surface of the pulp may be subjected to a surface sizing treatment with a film-forming polymer such as gelatin, starch, carboxymethylcellulose, polyacrylamide, polyvinyl alcohol, or a modified polyvinyl alcohol, if desired. Examples of the modified polyvinyl alcohol include carboxyl group-modified products, silanol-modified products, and copolymers with acrylamide. The coating amount of the film forming polymer in the case of re-surface sizing treatment by the said film-forming polymer, preferably ^{0.1~0.5g / m 2, 0.5~2.0g / m} 2 is particularly preferred. If desired, an antistatic agent, a fluorescent whitening agent, a pigment, an antifoaming agent, and the like can be added to the film-forming polymer.

The base paper is prepared by subjecting the pulp described above or a pulp slurry containing additives such as a filler, a sizing agent, a paper reinforcing agent, and a fixing agent, which are added as desired, to a paper machine such as a fourdrinier paper machine. After that, it is manufactured by winding. The surface sizing is performed either before or after the drying, and a calendering is performed after the drying and winding.

When the surface sizing treatment is performed after drying, the calendering treatment can be performed before or after the surface sizing treatment. However, the calendering treatment is performed in the final finishing step after the various treatments are performed. Is preferred.
For the calendering treatment, a known roll used in the production of ordinary paper, such as a metal roll or an elastic roll, can be used. The thickness of the base paper is finally adjusted to 50 to 250 μm by the above-described calendering process. The density of the base paper is preferably 0.8 to 1.3 g / cm ³ .
0 to 1.2 g / cm ³ is particularly preferred. It is desirable to apply an activation treatment such as corona discharge, flame treatment, glow discharge treatment, or plasma treatment to the surface of the base paper on which the intermediate layer is provided or the surface of the base paper on which the resin coating layer is provided.

-Resin Coating Layer- When a support having a resin coating layer provided on one side of a base paper is used, a resin capable of forming a film is selected as a resin constituting the resin coating layer. Water-resistant resins are preferred among the functional resins. As such a water-resistant resin, those which can be appropriately selected from those which can be melt-extruded at 170 to 345 ° C. can be used, and usually, homopolymers of α-olefin such as polyethylene and polypropylene and A polyolefin resin such as a mixture of the above is used.

The polyethylene has a density of 0.941.
g / cm ³ high density polyethylene (HDPE),
0.910 to 0.925 g / cm ³ low density polyethylene (LDPE), linear low density polyethylene (LL)
DPE) and the like, and mixtures thereof and the like can be used.

It is also possible to use a support in which a polystyrene resin is coated on one or both sides of the base paper. The glass transition point (Tg) of the polystyrene resin is 72 to
125 ° C is preferred, and more preferably 75 ° C to 120 ° C.
° C, more preferably 90 to 115 ° C. As the polystyrene resin, specifically, in addition to polystyrene, o-methyl-polystyrene, m-methyl-polystyrene, p-methyl-polystyrene, 2,5-dimethyl-
Polystyrene, 3,4-dimethyl-polystyrene, p-
Phenoxy-polystyrene, 2,5-difluoropolystyrene and the like are preferred. The polystyrene resin in the resin coating layer preferably contains isotactic polystyrene, particularly preferably at least 5% by weight of isotactic polystyrene. Similarly, a support coated with a polyester resin such as polyethylene terephthalate or polyethylene naphthalate can be used. The resin coating layer may contain a bluing agent, a fluorescent whitening agent, an antioxidant, an antistatic agent, and the like, and particularly preferably contains titanium dioxide.

When titanium dioxide is contained in the coating layer,
The form may be anatase type or rutile type, but anatase type is preferred when whiteness is prioritized, and rutile type is preferable when sharpness is prioritized. Also, in consideration of both whiteness and sharpness,
Anatase type and rutile type may be blended and used, or the coating layer containing titanium dioxide is made into two layers, one layer containing anatase type titanium dioxide, and the other layer containing rutile type titanium dioxide. May be.

The average particle size of titanium dioxide is as follows:
0.1 to 0.4 μm is preferred. When the average particle size is less than 0.1 μm, it is difficult to uniformly mix and disperse in the coating layer, and when the average particle size exceeds 0.4 μm, sufficient whiteness cannot be obtained, and projections are formed on the surface of the coating layer. And may adversely affect the image quality.

It is preferable that the surface of the titanium dioxide is treated with a silane coupling agent, and the silane coupling agent is preferably one whose terminal is ethoxy-modified or methoxy-modified.

Examples of the bluing agent include generally known ultramarine blue, cobalt blue, cobalt oxide phosphate, quinacridone pigments and the like, and mixtures thereof. The particle size of the bluing agent is not particularly limited, but is usually preferably in the range of 0.3 to 10 μm. In the present invention, when the bluing agent is used in the uppermost layer of the coating layer, it is preferably contained in an amount of 0.2 to 0.4% by weight, and when used in the lower layer side, it is preferably contained in an amount of 0 to 0.15% by weight.

The resin coating layer is formed by melting pellets containing the titanium dioxide and the like melted by heating, and, if necessary, diluting and melting with a resin for forming the coating layer, and running on the base paper that has been run. It is formed by coating by a normal laminating method, a sequential laminating method, or a laminating method using a single-layer or multilayer extrusion die such as a foot block type, a multi-manifold type, a multi-slot type, a laminator or the like. The shape of the single-layer or multi-layer extrusion die is not particularly limited, but generally includes a T die, a coat hanger die and the like.

--Intermediate Layer-- In the present invention, an intermediate layer comprising a polyester resin layer is provided on at least one surface of the above-mentioned support. The polyester resin constituting the polyester resin layer has a glass transition temperature (Tg) of preferably 65 ° C. or less and a molecular weight of 15,000 or more, more preferably a glass transition temperature (Tg) of −30 ° C. or more. The molecular weight is in the range of 45 ° C. and 18,000 to 30,000.

If the glass transition temperature (Tg) of the polyester resin in the intermediate layer exceeds 65 ° C., the surface of the toner tends to crack, and if the molecular weight is less than 15,000, the material tends to be easily cracked or melt-extruded. Problems such as deterioration of the film forming property of the film are likely to occur.

When the glass transition temperature (Tg) is 65 ° C. or less,
Commercially available polyester resins having a molecular weight of 15,000 or more include, for example, R251 (glass transition temperature: 25 ° C., molecular weight: 23000), R188 (glass transition temperature: 9 ° C., molecular weight: 25000), and R99 (glass). Transition temperature: -19 ° C, molecular weight: 23000), R98
(Glass transition temperature: −11 ° C., molecular weight: 23000),
R70 (glass transition temperature: -8 ° C, molecular weight: 2600
0), R275 (glass transition temperature: 4 ° C, molecular weight: 18)
000), R80 (glass transition temperature: −11 ° C., molecular weight: 26000), R274 (glass transition temperature: 11)
° C, molecular weight: 20,000), K1089 (glass transition temperature: 43 ° C, molecular weight: 18000), K650 (glass transition temperature: 36 ° C, molecular weight: 20,000) and the like. Also, Byron 30P (glass transition temperature: -28 ° C, molecular weight: 18000 to 20000), Byron GM900 (glass transition temperature: -20 ° C, molecular weight: 20000 to 26000), Byron GM400 manufactured by Toyobo
(Glass transition temperature: 19 ° C, molecular weight: 20000-25
000).

The intermediate layer may contain components such as a bluing agent, a fluorescent whitening agent, an antioxidant, an antistatic agent, and inorganic particles such as titanium dioxide as a whitening agent, if necessary. Can be. If the thickness of the intermediate layer is too small, the effect of the intermediate layer is diminished, and it is easy to form a film during melt extrusion. If it is too thick, it is difficult to form a uniform thickness of the transfer-receiving layer during coextrusion. From such a point, the thickness of the intermediate layer is preferably from 5 to 50 μm, and more preferably from 10 to 25 μm.

--Transferred Layer-- The transferred layer formed on the intermediate layer is not particularly limited, and a known transferred layer can be used. In the layer to be transferred,
Particularly, it is preferable to use a polyester resin. The type of the polyester resin in the layer to be transferred is not particularly limited as long as it is a polymer having a plurality of ester bonds.

Examples of the polyester resin include a polyester resin obtained by condensation of a dicarboxylic acid such as terephthalic acid, isophthalic acid, and succinic acid with a polyol such as ethylene glycol, diethylene glycol, propylene glycol, neopentyl glycol, and bisphenol A. Can be suitably used. The dicarboxylic acid mentioned here may be substituted by a sulfone group, a carboxyl group, or the like.

The polyester resin used for the layer to be transferred may be one obtained by synthesis or a commercially available product as it is. Commercially available polyester resins include, for example, Byron 200 and Byron 1 manufactured by Toyobo
03, Byron 300, Byron 500, Byron 28
0, Byron 290, etc., Chemit K-108 manufactured by Toray Industries, Inc.
9, Chemit K-1294, Chemit R-70, Chemit R-80, etc., Elitel UE340 made by Unitika
0, Elitel UE3221, Elitel UE321
0, Polyester UE3200, Polyester TP220, Polyester TP290 manufactured by Nippon Synthetic Chemical Industry Co., Ltd.
Polyester HP320, Polyester SP-13L
ATR-2009, ATR-2019 manufactured by Kao Corporation, etc.
Tufton U-5, Tufton NE382 and the like.

In the transferred layer, in addition to the polyester resin, various components used in known transferred layers may be used, if necessary.
For example, components such as a bluing agent, a fluorescent whitening agent, an antioxidant, an antistatic agent, and inorganic particles such as titanium dioxide as a whitening agent can be contained.

The intermediate layer and the layer to be transferred are melt-mixed with an extruder for a kneader, a heating kneading roll, a Banbury mixer, a kneader, etc., and then extruded on a base paper in a blended state. Can be provided by a melt extrusion lamination method,
In particular, it is preferable that the intermediate layer and the layer to be transferred are simultaneously formed by a melt coextrusion method.

In the melt coextrusion method, the composition of the intermediate layer and the composition of the layer to be transferred are melt-mixed by the above-mentioned means or the like, and then the coextrusion is performed by a coextrusion machine. The co-extrusion method includes a single manifold co-extrusion method, a multi-manifold co-extrusion method, and the like, and the multi-manifold co-extrusion method includes a multi-manifold internal combination method, a multi-manifold external combination method, and the present invention. Either of the methods can be adopted.

When the intermediate layer and the layer to be transferred are simultaneously formed by a co-extrusion method using a co-extrusion machine, it is preferable that the respective resins of the intermediate layer and the layer to be transferred have similar melting temperatures and fluid characteristics. Therefore, when selecting the resin for the intermediate layer and the layer to be transferred, for example, when the intermediate layer has a glass transition temperature (Tg) of 65 ° C. or less and a molecular weight of 15,000 or more, It is preferable to select resins having similar melting temperatures, fluid characteristics and the like of the respective resins. Simultaneous formation of the intermediate layer and the transferred layer by the co-extrusion method using a co-extrusion machine simplifies the formation of the intermediate layer and the transferred layer by using the co-extrusion method, and makes the electrophotography easier than the coating method using a solvent. This has the advantage that the durability of the material to be transferred is improved.

--- Electrophotographic Method-- The method of forming a multicolor image using the electrophotographic transfer material of the present invention is not particularly limited, but the following multicolor image formation using an intermediate transfer member is performed. A method can be preferably mentioned. First, a first color (for example, yellow) toner image is formed on the photosensitive drum by the copy operation start signal, and the intermediate transfer member also moves at substantially the same speed as the peripheral speed of the photosensitive drum. The formed toner image moves to a primary transfer position where the body contacts. next,
By the action of the transfer bias voltage applied to the core metal of the primary transfer bias transfer roll, the formed toner image is electrostatically attracted onto the intermediate transfer body, and the first color transfer of the primary transfer is performed. Is executed. At this time, due to the action of the high-resistance thin layer on the surface of the bias transfer roll,
The second color toner image (for example, magenta) goes to primary transfer.

In the second color toner image formed on the photosensitive drum in the same manner as the first color, a transfer bias voltage for the second color is applied to the metal core, and a two-color multiple transfer image is formed on the intermediate transfer member. . Thereafter, the primary transfer of the third color (for example, cyan) and the fourth color (for example, black) are sequentially performed in the same manner as in the case of the second color, and a full-color multiple transfer image is formed on the intermediate transfer member using the four color toners. You.

The four-color multi-transferred image on the intermediate transfer body after the primary transfer is transferred to the electrophotographic transfer material at the secondary transfer position while moving to the secondary transfer, and the secondary transfer is performed. The bias transfer roll of the means contacts the intermediate transfer member. The toner image and the electrophotographic transfer material transferred to the secondary transfer portion are sandwiched between the intermediate transfer member and the secondary transfer bias transfer roll, and a transfer voltage having a polarity opposite to the charged polarity of the toner is applied. By the action of the bias transfer roll, the toner image is electrostatically adsorbed on the image receiving layer of the electrophotographic transfer material, and the secondary transfer is performed. After completion of the secondary transfer, the electrophotographic transfer material is peeled off from the intermediate transfer body, sent to a fixing device by a conveyor belt, and is fixed.

As the color toner used in the electrophotographic method, a toner-forming material such as a binder resin composed of a polyester resin, a colorant (dye or pigment), and a charge control agent is melt-kneaded, crushed and classified. Are preferred. As the polyester resin for the toner, a polyester resin whose monomer is composed of bisphenol A ethylene oxide adduct / bisphenol A propylene oxide adduct / terephthalic acid / glycerin, a polyester resin composed of bisphenol A ethylene oxide adduct / dodecylsuccinic acid / terephthalic acid And a polyester resin comprising bisphenol A ethylene glycol adduct / fumaric acid / isopropylene glycol. As the polystyrene resin, styrene-
Acrylic copolymer resins are preferred.

[0038]

EXAMPLES The present invention will be described in more detail with reference to the following Examples, but it should not be construed that the invention is limited thereto.
In the examples, "parts" indicates parts by weight, and "%" indicates% by weight.

(Preparation of base paper) Wood pulp mixture (LB
KP / NBSP = 2/1) to obtain a pulp slurry having a Canadian freeness of 250 cc. Then, after diluting this pulp slurry with water, while stirring, 1.0% of anionic polyacrylamide per pulp (Polystron 195, manufactured by Arakawa Chemical Co., Ltd., molecular weight: about 110)
10,000%), aluminum sulfate 1.0%, and polyamide polyamine epichlorohydrin 0.15% (sponge 55
7: Dick Hercules (trade name). Further, after adding 0.4% of epoxidized behenamide or alkyl ketene dimer, sodium hydroxide and cationic polyacrylamide 0.5% were added to adjust the pH to 7.
% And an antifoam 0.1%. The pulp slurry adjusted as described above was made into a paper at 180 g / m ² .

The surface of the base paper thus adjusted was adjusted to a water content of about 2% in an oven, and then an aqueous solution having the following formulation was size-pressed as a surface size liquid, and the amount of the applied liquid was 20 g / m2 on the surface of the base paper. ² was attached. Polyvinyl alcohol: 4.0% Calcium chloride: 4.0% Fluorescent whitening agent: 0.5% Antifoaming agent: 0.005%
The thickness was adjusted to 60 μm to obtain base paper.

(Example 1) After the surface of the base paper was subjected to a flame treatment, low-density polyethylene (density: 0.9
2. Softening temperature: 105 ° C.) was melted by an extruder, extruded from a T-die and laminated to form a support having a 20 μm thick coating layer. On another surface of the support, a copolyester (byron GM900, manufactured by Toyobo Co., Ltd., glass transition temperature: -20 ° C, molecular weight: 2) was formed by a co-melt extrusion method.
6000) and a 20 μm-thick transfer layer made of a copolymerized polyester (terephthalic acid / bisphenol A ethylene oxide adduct, glass transition temperature: 72 ° C., molecular weight 13000), An electrophotographic transfer material was prepared.

Example 2 The intermediate layer in Example 1 was formed by copolymerizing polyester (glass transition temperature: 25 ° C., molecular weight:
23,000), except that an intermediate layer having a thickness of 10 μm was formed in the same manner as in Example 1.

Example 3 The intermediate layer in Example 1 was made of polyethylene terephthalate (glass transition temperature: 71 ° C.)
A transfer material for electrophotography was produced in the same manner as in Example 1 except that the intermediate layer having a thickness of 10 μm was used.

(Comparative Example 1) The same base paper as in Example 1 was subjected to a flame treatment, and then a transfer-receiving material for electrophotography having the same 20 μm-thick transfer layer as in Example 1 was produced on the surface.

COMPARATIVE EXAMPLE 2 A cast-coated paper was prepared by forming a cast coat layer on the surface of the same base paper as in Example 1, and the same transfer-receiving layer as in Example 1 was formed on the cast coat layer. A transfer material was prepared.

(Comparative Example 3) After the both sides of the same base paper as in Example 1 were subjected to flame treatment, low-density polyethylene (density: 0.92, softening temperature: 105 ° C) was melted on one side by an extruder. The support was extruded from a die and laminated to form a coating layer having a thickness of 20 μm. An electrophotographic transfer material was prepared in which the same transfer layer as in Example 1 was formed on the other surface of the support.

(Comparative Example 4) After the both sides of the same base paper as in Example 1 were subjected to flame treatment, low density polyethylene (density: 0.92, softening temperature: 105 ° C) was melted on one side by an extruder. Extruded from a die and laminated to form a 20 μm thick coating layer. Low density polyethylene (density: 0.92, softening temperature: 105 ° C) was melted on the other side of the base paper by an extruder, and extruded from a T die and laminated. Thus, a support having a coating layer having a thickness of 10 μm was prepared. 10μ of this support
An electrophotographic transfer material was prepared in which the same transfer layer as in Comparative Example 1 was formed on the surface side of the m-thick coating layer.

The transfer material for electrophotography was manufactured by Fuji Xerox Co., Ltd. using a color laser printer “Colo”.
r Laser Wind 3310 "to form a color image. The color image surfaces were evaluated for 1) toner surface cracks, 2) yellow loss (Y loss), and 3) gloss unevenness. <Evaluation of Toner Surface Cracking and Yellow Omission> The obtained color image surface was visually evaluated for toner surface cracking and yellow omission, and the degree is shown in Table 1.

<Measurement / Evaluation of Gloss> Printing apparatus (Color Laser wind, manufactured by Fuji Xerox Co., Ltd.)
Using 3310), images of respective color patterns having a density of 0%, 50% (gray) and 100% (black) in a square of 20 cm × 20 cm were printed. Thereafter, the gloss of the surface of the electrophotographic transfer material was measured with a gloss meter (HG-246, manufactured by Suga Test Instruments Co., Ltd., condition: incident light at 60 degrees). The 0% density portion was defined as a low gloss density region, the 50% density portion was defined as a medium gloss density region, and the 100% density portion was defined as a high gloss density region. The results are shown in Table 1.

Table 1 summarizes the layer structure of each of the electrophotographic transfer materials thus obtained. In the table, ··· Copolymerized polyester (terephthalic acid / bisphenol A ethylene oxide adduct, glass transition temperature: 72 ° C, molecular weight 13000) · · Low density polyethylene (density: 0.92, softening temperature: 105 ° C) · · Polyethylene Terephthalate (glass transition temperature T
g: 71 ° C.) Copolymerized polyester (glass transition temperature: −20)
° C, molecular weight: 26000) Copolymerized polyester (glass transition temperature: 25)
° C, molecular weight: 23000)

[0051]

[Table 1]

[0052]

[Table 2]

From Tables 1 and 2, Examples 1 and 2 are shown.
In the electrophotographic transfer material, the polyester resin constituting the intermediate layer has a glass transition temperature (Tg) of 65 ° C. or less,
The molecular weight is 15,000 or more, 1) cracks on the toner surface, 2) no yellow loss (Y loss)
In addition, 3) shows that there is no gloss unevenness. In Example 3, the glass transition temperature of the polyester resin constituting the intermediate layer exceeded 71 ° C. and 65 ° C., and uneven gloss and missing yellow (Y missing) were almost eliminated. Although it does not occur, cracking of the toner surface is slightly generated. On the other hand, in Comparative Example, gloss unevenness occurred in all cases except Comparative Example 2.
Indicates that the toner has many cracks on the surface, and yellow missing (Y
Omission) has also occurred.

[0054]

According to the transfer material for electrophotography of the present invention, cracks on the toner surface can be reduced or eliminated, 2) no yellow dropout (Y dropout) does not occur, and 3) uneven gloss is produced. As a result, a high-quality image can be obtained. According to the method for producing a transfer material for electrophotography of the present invention, a transfer material for electrophotography having the above characteristics can be easily produced.

Claims (3)

[Claims] 1. An electrophotographic transfer material having a transfer layer on at least one surface of a support, wherein an intermediate layer made of a polyester resin layer is provided between the transfer layer and the support. A transfer material for electrophotography, comprising: 2. The transfer material for electrophotography according to claim 1, wherein the polyester resin constituting the intermediate layer has a glass transition temperature (Tg) of 65 ° C. or less and a molecular weight of 15,000 or more. . 3. A method for producing an electrophotographic transfer material having an intermediate layer and a transfer layer provided in this order on a support, wherein the transfer layer and the intermediate layer are melt-coextruded on the support. A method for producing a material to be transferred for electrophotography, characterized by being formed by a method.