JP2965491B2 - Copy transfer material for electrophotography - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for forming an image using a toner, such as an electrophotographic apparatus and an electrostatic recording apparatus, in which an obtained toner image can be retransferred to another final transfer material. The present invention relates to a copy transfer material for electrophotography.

[0002]

2. Description of the Related Art Conventionally, it is widely known to transfer an image three-dimensionally by using a technique of copying pictures. For example, a water-soluble paste represented by dextrin is coated on a base material such as paper. The required image is formed on this coating film using acrylic ink by screen printing, etc., and the paper having this image is immersed in water to dissolve the dextrin, and the acrylic ink image floating in the water is converted into a three-dimensional object such as pottery. 2. Description of the Related Art A hydraulic transfer method for copying by hydraulic pressure is widely known. An example of direct application of the transfer paper used in this method to electrophotography is Muto Kogyo's Templin. This transfer material is made of dextrin film on rice paper as a transfer material,
After applying this to an electrophotographic apparatus to form a toner image on the surface of the dextrin, this transfer material is passed through an organic solvent capable of softening the resin in the toner, and transferred to a transfer medium to be re-transferred to the toner image. After applying this adhesive force, the transfer material is brought into close contact with the re-transfer medium so that the toner image faces the re-transfer medium, and then water is applied from the back of the paper to dissolve the dextrin film and transfer only the toner image. It is.

However, in the case of a transfer material formed by forming a water-soluble coating film on such opaque paper, not only is it difficult to adjust the position at the time of retransfer, but also because of the influence of moisture in the atmosphere, it is difficult to form an image before forming an image. The transfer material surface is softened, causing a problem that the softened dextrin adheres to a photosensitive drum or the like in the electrophotographic apparatus. Further, as described above, since it is sensitive to moisture in the air, it greatly expands and contracts with respect to the amount of moisture, causing unnecessary leaving curl of the transfer material, which significantly deteriorates the paper transport property in the apparatus.

[0004] To solve the above two problems,
No. 086 proposes a retransfer material using polyvinyl alcohol which is a saponified product of vinyl acetate instead of dextrin. The transfer material proposed here forms an acrylic resin film on paper coated with a silicone resin, and further coats a mixture of silicone antifoaming agent and Niseka Chemical's Casesol 0-5. In the retransfer itself, after forming a toner image on this coating film with an electrophotographic apparatus, the caseol film is peeled off from the base material so that the toner image faces the retransfer medium. Overlap.

By applying heat and pressure, the resin in the toner image is softened to obtain an adhesive force to the retransfer medium, and after cooling, 80% of ethyl alcohol is applied from the back surface of the casesol film.
% Of the aqueous solution to reduce the adhesive strength between the casesol film and the toner image, thereby completing the retransfer.

According to this method, since the thin film having the toner image is peeled off from the base material, the film becomes substantially transparent, and there is an advantage that the alignment becomes easy.

[0007]

However, in the above-mentioned conventional example, since the coating material used is a partially saponified product of vinyl acetate, it is as sensitive to moisture in the air as templin. There is a problem that the water resistance is extremely poor, and further, the coating film remains due to the dissolution of the film at the time of peeling off the coating film. Further, it has been found that the use of silicone for the release film causes a problem that the film peels off during the transfer of the transfer material in the electrophotographic apparatus.

Accordingly, it is an object of the present invention to provide a transfer material for electrophotographic copying in which the water resistance is improved, the amount of curl in storage is reduced, and the releasability of the film layer is stabilized.

[0009]

That is, a first aspect of the present invention relates to an electrophotographic copy transfer material in which a polymer resin film is formed on the front and back of a base material mainly composed of paper. The film consists of two layers, an adhesive layer and a transfer layer .
An electrophotographic copy transfer material characterized by being formed of a resin selected from resins .

[0010] In a second aspect, the present invention provides the first aspect,
This is the case where the polymer resin film can be peeled off at the interface between the adhesive layer and the transfer layer.

A third aspect of the present invention is the first aspect of the present invention,
The adhesive strength between the adhesive layer and the transfer layer is 1.5 g / cm or more and 4 g / c
m or less.

[0012] A fourth invention is directed to the first invention, wherein:
This is the case where the adhesive layer and the backing layer contain a resin selected from acrylic, polyester and nylon.

[0013] The fifth invention is the first invention, wherein:
This is the case where the transfer layer contains polyvinyl alcohol.

According to a sixth aspect of the present invention, in the fifth aspect,
This is the case where the transfer layer is made of polyvinyl alcohol containing an organic silicone resin.

According to a seventh aspect of the present invention, in the first aspect,
The transfer layer contains polyvinyl alcohol obtained by saponifying polyvinyl acetate of 95% or more and polyvinyl alcohol obtained by saponifying polyvinyl acetate of 90% or less, and the content of polyvinyl alcohol having a saponification degree of 95% or more is 25% by weight as a solid component. In this case, the content is at least 75% by weight. The transfer layer is made of not only partially saponified vinyl acetate but also partially saponified vinyl acetate and 95% or more saponified vinyl acetate as in the conventional casesol 0-5. It is stable against it.

According to an eighth aspect of the present invention, in the first aspect,
This is a case where the surface specific resistance of the transfer layer is 10 ⁸ to 10 ¹² Ω / □ in an environment of 20 ° C. and 65% RH.

[0017]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a copy transfer material 1 for electrophotography according to the present invention.
FIG. 2 is a schematic cross-sectional view showing the layer configuration of FIG. Reference numeral 11 denotes a base material of the transfer material 1, which is a medium-quality or high-quality plain paper, or a paper in which one or both surfaces of these papers are provided with a surface coating for filling, so-called coated paper, art paper, etc. Is used. In the case of paper, the basis weight is preferably 30 g / m ² or more,
5 g / m ² or more is more preferable. If the paper weight is less than 30 g / m ² , it is difficult to ensure the transportability of the electrophotographic apparatus even if the coating resin film is thickened. The basis weight is preferably from 200 g / m ² or less, more preferably 150 g / m ² or less. 2
If it exceeds 00 g / m ² , the rigidity of the base paper is too high.
The transportability is likely to be poor. The base paper is added with 0.2 to 4% by weight of an inorganic salt such as sodium chloride in order to maintain good image transferability in an electrophotographic apparatus, and has a volume resistance of 20 ° C. and 65% RH. Preferably, it is adjusted to 10 ⁸ to 10 ¹⁰ Ω · cm after standing for 24 hours.

Reference numeral 12 denotes an adhesive layer, which is provided to prevent the transfer layer 14 to be applied later from easily peeling off in the electrophotographic apparatus. Examples of the material used include an aqueous acrylic emulsion, water-soluble acrylic, water-soluble polyester, 6.6 nylon, polyacrylonitrile, and an acrylic resin soluble in an organic solvent.

The mutual material selection of the transfer layer 14 and the adhesive layer 12 is also affected by the adhesive strength, and the adhesive strength is 1.5 g / 90 ° peeling at least so that the transfer layer 14 and the adhesive layer 12 are not separated by the transport force in the electrophotographic apparatus. cm or more, and a transfer layer 14 and a release layer 13 which will be described later.
The thickness is preferably 4 g / cm or less so that the film is not broken when the retransfer film layer made of is peeled from the substrate. To achieve this condition, the transfer layer 1 described below must be used.
Preferably, 4 contains a small amount of an organic silicone.

Next, the transfer layer 14 will be described. This layer receives a toner image by an electrophotographic apparatus, holds the toner image at least until a re-transfer step is performed by heating, and has sufficient It is required to have excellent toner release performance. It is also required to have sufficient water resistance compared to the prior art. That is, it is necessary that water permeability is excellent while ensuring the solvent permeability during retransfer. Specifically, a transfer layer is formed by mixing polyvinyl alcohol saponified with polyvinyl acetate of 95% or more and polyvinyl alcohol saponified with polyvinyl acetate of 90% or less. The mixing ratio is preferably such that the content of polyvinyl alcohol having a high degree of saponification of 95% or more is 10% by weight or more, more preferably 25% by weight or more, as a solid content ratio. If less than 10% by weight, 90
% Or less of the polyvinyl alcohol having a low saponification degree, and the surface layer is dissolved in a high-temperature environment, which may contaminate members in the electrophotographic apparatus. Furthermore, high saponification degree polyvinyl alcohol is 7
When the content is 5% by weight or more, the arrangement of linear polymers forming the membrane itself has a high degree of regularity as in the case of a cellulose membrane, and thus there is a possibility that the membrane shrinks due to a change in the amount of water in the air. That is, the polyvinyl alcohol having a high degree of saponification is more preferably 25% by weight or more and less than 75% by weight as a solid content ratio. If necessary, a cationic or nonionic antistatic agent can be added to the transfer layer 14 to improve electrophotographic transferability. The amount of the antistatic agent may be adjusted so that the target surface specific resistance value is 10 ⁸ to 10 ¹² / □. Further, an inorganic white pigment such as a silica powder may be mixed in order to ensure paper transportability. Further, in order to satisfy the above-mentioned stripping properties, 0.5
It is preferable to mix up to 7% by weight of an organic silicone. If the amount is less than 0.5% by weight, the adhesive strength is so strong that the above-mentioned breakage occurs.

Regarding the thickness of each layer, the adhesive layer 12 is preferably a thin layer so as not to cause splitting of the film.
It is preferably from 10 μm to 10 μm. If it is less than 2 μm, unevenness tends to occur, and if it exceeds 10 μm, in-layer peeling tends to occur.

Turning now to the backing layer 13, this layer contracts due to the environment in which the transfer layer 14 is left,
It is provided to further reduce the occurrence of some curling, and the organic solvent-soluble resin used for the adhesive layer described above is used. As the resin, any of a thermosetting resin and a thermoplastic resin can be used, and for example, an acrylic resin, an epoxy resin, a butyral resin, a vinyl chloride resin, or the like can be used. The coating film thickness is 1 to
20 μm is preferred. If it is less than 1 μm, sufficient rigidity cannot be obtained, and if it exceeds 20 μm, too much rigidity is imparted, and the transportability in the electrophotographic apparatus is reduced. The film thickness for obtaining more stable rigidity is 2 to 20 μm.

The thickness of the transfer layer 14 is preferably 8 μm or more. If it is thinner than this, insufficient strength such as breakage of the film when peeled from the substrate is likely to occur. Also, 50μ
m or less is preferable. If the thickness is larger than this, the film after peeling becomes hard, and the reproducibility of the curved surface at the time of retransfer tends to decrease. A more preferable film thickness is 10 μm or more and 40 μm or less.

Next, the electrophotographic toner applicable to the copy transfer material of the present invention will be described in detail. Basically, for electrophotography, a binder resin mainly composed of a resin such as a styrene-acrylic copolymer, a styrene-butadiene copolymer, an epoxy, and a polyester contains dyes and pigments such as yellow, cyan, and magenta in addition to carbon black. Toner is available. Among them, the color toners described below are particularly capable of further bringing out the effects of the copy transfer material of the present invention.

The toner powder for a color electrophotographic apparatus is
It is necessary that the toner has good meltability and color mixing when heat is applied, and a sharp melt toner having a low softening point and a short melting time is preferable.

By using a sharp-melt toner, the color reproduction range of a copy can be widened and a color copy faithful to a multicolor image of a document can be obtained satisfactorily.

Such a sharp-melt toner includes, for example, a binder resin such as a polyester resin or a styrene-acrylic resin, a colorant (a dye, a sublimable dye),
The toner is manufactured by melt-kneading, pulverizing and classifying a charge control agent and the like. If necessary, an external addition step of adding various external additives to the toner may be added.

The color toner preferably uses a polyester resin as the binder resin in consideration of the fixing property and the sharp melt property. The sharp melt polyester resin is a polymer compound having an ester bond in the main chain of a molecule synthesized from a diol compound and a dicarboxylic acid. In particular,

[0030]

Embedded image (Wherein R is an ethylene or propylene group, x,
y is a positive integer of 1 or more, and the average value of x + y is 2 to 10. ) As a diol component, and a carboxylic acid component comprising a divalent or higher carboxylic acid or an acid anhydride thereof or a lower alkyl ester thereof (for example, fumaric acid,
A polyester resin obtained by at least co-condensation polymerization of maleic acid, maleic anhydride, phthalic acid, terephthalic acid, trimellitic acid, pyromellitic acid, etc.) is more preferable since it has sharp melting properties.

The softening point of the sharp melt polyester resin is preferably from 60 to 120 ° C. FIG. 2 shows the softening point characteristics of the toner containing the sharp melt polyester resin as a binder resin.

Using a flow tester CFT-500 type (manufactured by Shimadzu Corporation), a die (nozzle) diameter of 0.5 mm,
A plunger descent-temperature curve of toner drawn when a 50 kg extrusion load is applied to a thickness of 1.0 mm, the preheating time is 300 seconds, the preheating time is 300 seconds, and the temperature is increased at a constant speed of 5 ° C./min ( (Hereinafter referred to as a softening S-shaped curve). The toner used as the sample is a fine powder precisely weighed 1 to 3 g, and the cross-sectional area of the plunger is 10 cm ² . The softening S-shaped curve is as shown in FIG. As the temperature rises at a constant speed, the toner is gradually heated and starts to flow (plunger descent A → B). When the temperature is further increased, the toner in the molten state flows out greatly (B → C → D), the plunger descent stops, and the process ends (D → E).

The height H of the S-shaped curve indicates the total amount of outflow, and H /
The temperature T ₀ corresponding to the C point 2 indicates the softening point of the toner.

Such a sharp-melting toner or resin is defined as having a temperature at which the melt viscosity is 10 ⁵ , T ₁ ,
When the temperature at which 5 × 10 ⁴ cp is indicated is T ₂ , T ₁ = 90 to 150 ° C. | ΔT | = | T ₁ −T ₂ | = 5
A resin that satisfies the condition of 30 ° C.

A sharp-melt toner or resin having such a temperature-melt viscosity characteristic is characterized in that the viscosity thereof is extremely sharply reduced by heating. Such a decrease in viscosity causes appropriate mixing between the uppermost toner layer and the lowermost toner layer, and furthermore, sharply increases the transparency of the toner layer itself and causes good color-reduction mixing.

Next, specific examples of the present invention will be described. In the specific examples, “parts” indicates “parts by weight”.

Example 1 A so-called coated paper obtained by filling both sides of a high-quality paper having a basis weight of 80 g / m ^{2 with} a coating liquid comprising starch and calcium carbonate was used as a base paper and transferred according to the following formulation. Material A was obtained.

<Adhesive Layer and Backing Layer> A coating liquid consisting of 100 parts of acrylic resin (cover coat resin LO-316, manufactured by Yoyo Chemical Co., Ltd.) and 100 parts of toluene was coated with a screen coater to form an adhesive layer of 6 g.
/ M ² (thickness 6 μm) and the backing layer 4 g / m ² (thickness 4
μm).

<Transfer Layer> Low Saponification Degree Polyvinyl Alcohol (Saponification Degree 88%, Casesol 05, manufactured by Nikka Chemical), Solid Content 14% 50 parts High Saponification Degree Polyvinyl Alcohol (Kuraray Poval PVA110), Solid Content 14% 50 parts Water 5 parts Antistatic agent (Cation AB, manufactured by NOF Corporation) 2.5 parts Silicone defoamer (KM73, manufactured by Shin-Etsu Chemical Co., Ltd.) 4 parts A coating liquid consisting of 4 parts was prepared, and the thickness was 16 μm on the adhesive layer. The coating film was formed with a screen coater.

The adhesive strength between the transfer layer and the adhesive layer of the obtained transfer material was 2 g / cm. The surface resistance of the transfer layer is 1
0 ¹¹ Ω / □.

When a color image was copied from the transfer material using a Canon CLC700 (Canon color copying machine), a good color image was obtained without peeling of the coating film. Further, when this paper was allowed to stand for about 5 minutes in a low humidity environment of 23 ° C. and 5%, lifting of the end of the transfer material with the transfer layer facing upward occurred by about 5 mm. In this state, copying was performed by the above-described color copying machine, and there was no problem in paper passing performance.

Further, the transfer layer having the toner image was peeled off from the obtained transfer material, and was brought into close contact with the prepared coated cardboard so that the toner image was directly opposed. When an aqueous alcohol solution was applied from the back surface of the transfer layer, the PVA film swelled without melting, and the toner image was self-separated to complete the copying.

Comparative Example 1 A transfer material B was obtained in the same manner as in Example 1 except that the backing layer was omitted.

When this transfer material B was allowed to stand for 5 minutes in an environment of 23 ° C. and 5%, lifting of the edge of the transfer material with the transfer layer facing upward occurred by 20 mm or more. In this state, a paper-passing test was performed using the CLC700 in the same manner as in Example 1. As a result, the amount of curl was too large, so that the electrostatic attraction to the transfer drum in the main body could not be performed, and a paper jam occurred.

Example 2 A so-called coated paper (basic weight of 127 g / m ² ) in which both sides of a high-quality paper having a basis weight of 104 g / m ² were capped with a coating liquid composed of styrene butadiene rubber, starch, kaolin, and calcium carbonate. m ² ) was used as a base paper to obtain a transfer material C according to the following formulation.

<Adhesive Layer and Backing Layer> A coating liquid consisting of 100 parts of acrylic resin (Covercoat Resin LO-316, manufactured by Yoyo Chemical Co., Ltd.) and 100 parts of toluene was coated with a screen coater to form an adhesive layer of 4 g.
/ M ² (thickness 4 μm) and the backing layer 2 g / m ² (thickness 2
μm).

<Transfer Layer> Low Saponification Degree Polyvinyl Alcohol (Saponification Degree 88%, Casesol 05, manufactured by Nikka Chemical), Solid Content 14% 75 parts High Saponification Degree Polyvinyl Alcohol (Kuraray Poval PVA110), Solid Content 14% 25 parts Water 5 parts Antistatic agent (Cation AB, manufactured by NOF Corporation) 2.5 parts Silicone defoamer (KM73, manufactured by Shin-Etsu Chemical Co., Ltd.) 4 parts is prepared and applied to the adhesive layer so as to have a thickness of 16 μm. The film was formed with a screen coater.

The adhesive strength between the transfer layer and the adhesive layer of the obtained transfer material was 3 g / cm. The surface resistance of the transfer layer is 1
0 ¹¹ Ω / □.

The above transfer material was replaced with a CLC700 made by Canon.
When a color image was copied with a (Canon color copying machine), a good color image was obtained without peeling of the coating film. Further, when the paper was allowed to stand for about 5 minutes in a low humidity environment of 23 ° C. and 5%, lifting of the edge of the transfer material with the transfer layer facing upward occurred by about 3 mm. In this state, copying was performed by the above-described color copying machine, and there was no problem in paper passing performance.

Further, the transfer layer having the toner image is peeled off from the obtained transfer material, and is brought into close contact with the prepared coated cardboard so that the toner image faces directly. When an aqueous alcohol solution was applied from the back surface of the transfer layer, the PVA film swelled without melting, and the toner image was self-separated to complete the copying. However, the transfer layer film slightly melted in the portion to which a large amount of the ethyl alcohol aqueous solution was applied.

[Comparative Example 2] A transfer material D was obtained in the same manner as in Example 2 except that the backing layer was omitted and the PVA of the transfer layer was all low saponified.

When this transfer material B was left in an environment of 23 ° C. and 5% for 5 minutes, the edge of the transfer material was lifted by 15 mm or more with the transfer layer facing upward. In this state, a paper-passing test was performed using the CLC 700 in the same manner as in Example 1. As a result, the amount of curl was too large, so that the electrostatic attraction to the transfer drum in the copying machine could not be performed, and a paper jam occurred.

When this paper was left in an environment of 30 ° C. and 80%, softening of the surface PVA started in about one week.

Example 3 A transfer material E was obtained in the same manner as in Example 1 except that epoxy resin was used as the backing material and the thickness of the backing layer was changed to 15 μm.

When copying was performed with a color copying machine in the same manner as in Example 1, good paper passing characteristics and image quality were obtained. However, since the backing layer was thick in the paper conveyance, the paper had a strong stiffness, hitting the paper feed guide in the machine, and was almost at the limit.

Comparative Example 3 A transfer material F was obtained in the same manner as in Example 1 except that the thickness of the backing layer was changed to 25 μm.

In this case, since the paper is too stiff, if there is a curved portion in the paper conveyance, the paper will bounce and the toner on the transfer material will be scattered.

[0058]

As described above, a resin coating is applied to both sides of the paper which is the base material of the transfer material of the present invention, and one side of the paper is used as an adhesive layer to form a transfer layer thereon. According to the transfer material, the left curl in a low-humidity environment can be further reduced, so that a copy transfer material for electrophotography having more stable paper passing characteristics can be obtained.

[Brief description of the drawings]

FIG. 1 is a schematic longitudinal sectional view of a copy transfer material of the present invention.

FIG. 2 is a melting characteristic diagram of a toner used for a transfer material of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Substrate 12 Adhesive layer 13 Backing layer 14 Transfer layer

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-4-361086 (JP, A) JP-A-5-301497 (JP, A) JP-A-4-332700 (JP, A) JP-A-3-3 243399 (JP, A) JP-A-5-24395 (JP, A) JP-A-7-117327 (JP, A) JP-A 63-63467 (JP, U) (58) Fields investigated (Int. Cl. ⁶ , DB name) G03G 7/00 B44C 1/16-1/17 B41M 3/12

Claims (8)

(57) [Claims] 1. A transfer material for electrophotographic copying in which a polymer resin film is formed on the front and back of a base material mainly composed of paper, wherein the polymer resin film on the surface is composed of an adhesive layer and a transfer layer,
The polymer resin film on the back side serves as a backing layer ,
A transfer material for electrophotographic copying, characterized by being formed of a resin selected from thermoplastic resins and thermoplastic resins . 2. The transfer material for electrophotographic copying according to claim 1, wherein the polymer resin film is peelable at an interface between the adhesive layer and the transfer layer. 3. The adhesive strength between the adhesive layer and the transfer layer is 1.5 g / c.
2. The transfer material for electrophotographic copying according to claim 1, wherein the transfer weight is from m to 4 g / cm. 4. The transfer material for electrophotographic copying according to claim 1, wherein the adhesive layer and the backing layer contain a resin selected from acrylic, polyester and nylon. 5. The transfer material for electrophotographic copying according to claim 1, wherein the transfer layer contains polyvinyl alcohol. 6. The transfer material for electrophotographic copying according to claim 5, wherein the transfer layer comprises an organic silicone in polyvinyl alcohol. 7. A transfer layer comprising polyvinyl alcohol and polyvinyl acetate obtained by saponifying 95% or more of polyvinyl acetate.
2. The transfer material for electrophotographic copying according to claim 1, wherein the transfer material for electrophotography contains polyvinyl alcohol having a saponification degree of 95% or less and a saponification degree of 95% or more in a solid content of 25% by weight or more and less than 75% by weight. 8. The surface resistivity of the transfer layer is 20 ° C., 65
The transfer material for electrophotographic copying according to claim 1, which has a density of 10 ⁸ to 10 ¹² Ω / □ in a% RH environment.