JPS63269163A - Thermal transfer recording method - Google Patents

Abstract

PURPOSE:To improve the transferring property of an image forming medium by coating the image forming medium holding a toner image with a fluorine resin, and by incorporating a mold releasable resin material in a toner constituting material. CONSTITUTION:An electrostatic latent image is formed on the image forming medium 1, and the toner image 6 is formed o said medium by developing the electrostatic latent image with a toner, and then, the toner image 6 is transferred by bringing said toner image into contact with a recording medium 7 in a heated state of the toner image 6 by a heating means 4. In this case, the surface of the image forming medium 1 is coated with the fluorine resin, and the mold releasable resin material is incorporated in the toner constituting material. The toner is composed from a microcapsule toner comprising a shell material composed of a material having a relatively high glass transition point and a core material composed of a material having the lower glass transition point than that of the shell material, whereby the good transfer is carried out, without occurring thermal blocking.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a recording method for thermally transferring a toner image onto a recording medium.

[Conventional technology]

Conventionally, in xerography and transfer-type electrostatic recording, many methods have been proposed in which a toner image formed electrostatically is transferred to a recording medium by applying pressure or heat.

A typical pressure transfer method is USP-4155.
093, etc., however, images obtained by pressure transfer have problems in terms of fixability due to the immaturity of pressure fixing technology, and it is difficult to say that it has been fully put into practical use, limiting its widespread use. has been done.

On the other hand, thermal transfer methods are also available, for example in Japanese Patent Laid-Open No. 61-12
9672, etc., but although it is superior to pressure transfer in terms of fixing performance, it has not reached a sufficient processing speed to be applied to current copying machines and printers.

' Fig. 3 is a diagram showing an example of a conventional thermal transfer recording device, in which l is an image forming medium, 2 is an electrostatic image forming means, 3 is a developing means, 4 is a heating means, 5 is a transfer means, 6 is a toner image, 7
is a recording medium. In addition, in the figure, peeling means, cleaning means,
Static elimination means, etc. are omitted.

In the figure, an electrostatic image is formed on an image forming medium 1 by an electrostatic image forming means 2, and a toner image 6 is formed by a developing means 3. The formed toner image is heated and fixed in the area before the transfer by a heating means 4 made of, for example, a heat ray lamp. The fixed toner image is transferred onto the recording medium 7 by the transfer means 5.

FIG. 4 is a diagram showing another example of a conventional thermal transfer recording apparatus, which is the same as FIG. 3 except that the transfer roll is a thermal roll equipped with a heater.

The conventional thermal transfer recording apparatuses shown in FIGS. 3 and 4 are constructed so that heat is not directly transmitted to the toner storage tank or the developing device.

[Problems to be solved by the invention]

By the way, in the thermal transfer method, unlike when used in a place well away from the recording unit such as a dedicated heat fixing device, it is necessary to prevent the toner from causing thermal blocking due to the influence of heat on the toner storage tank and developing device. Therefore, there is a problem that the toner image cannot be sufficiently heated. That is, in conventional thermal transfer recording methods, the toner image is heated only for a certain period of time before being transferred, heated only in the area near the transfer area, or the transfer roll also serves as a heating means and attempts to transfer the image using only the heat from there. This has been an obstacle to increasing the transfer speed.

Furthermore, conventional thermal transfer recording methods have not been sufficient in terms of transferability and mold release properties.

The present invention is intended to solve the above-mentioned problems, and improves transferability by coating an image forming medium that holds a toner image with a fluororesin and also incorporating a releasing resin material into the toner constituent materials. It is an object of the present invention to provide a thermal transfer recording method that enables

[Means for solving problems]

To this end, the thermal transfer recording method of the present invention forms an electrostatic latent image on an image forming medium, develops the electrostatic latent image with toner to form a toner image, and heats the toner image with a heating means. A recording method in which a toner image is transferred by contacting with a recording medium is characterized in that the surface of the image forming medium is coated with a fluororesin and a releasing resin material is contained in the constituent materials of the toner.

[Effect]

In the thermal transfer recording method of the present invention, by coating the surface of the image forming medium with a fluororesin and incorporating a releasing resin material into the constituent materials of the toner, transferability and releasing ability can be improved.

〔Example〕

Examples will be described below with reference to the drawings.

FIG. 1 is a diagram showing an embodiment of the thermal transfer recording method of the present invention, and the same numbers as in FIG. 3 indicate the same contents.

In the figure, the back side of the toner image forming surface of the image forming medium 1;
A heating means 4 is provided inside the medium drum, and the image forming medium 1 itself is heated to raise its temperature. Therefore, the toner image 6 is sufficiently heated from development to transfer.

The toner is a microcapsule toner that is composed of an outer shell made of a material with a relatively high glass transition point and a core material made of a material with a glass transition point lower than that of the outer shell material, so that thermal blocking does not occur. , and enable good transfer.

Various structures, materials, and manufacturing methods for microcapsule toner have already been proposed, but the purpose of these is to improve both the pressure fixability and the prevention of blocking due to pressure. The core material has been selected with a focus on mechanical strength, such as using soft or liquid materials.

The microcapsule toner used in the thermal transfer recording method of the present invention has both improved thermal transferability and prevention of blocking due to heat, and differs from conventional microcapsule toners in both material characteristics and toner characteristics. Use a thermally stable polymer with a relatively high transition point, such as styrene, acrylic, or phenol, and use a polymer with a lower transition point than the outer shell material, such as ester or epoxy, as the core material. Polymer or wax
The core material or the outer shell is made of magnetic powder, as appropriate.
The inclusion of carbon black, dyes, etc. for the purpose of adjusting coloring properties, charging properties, fluidity, etc. is the same as in conventional microcapsule toners.

Note that instead of the microcapsule structure, a material coated with a substance relatively stable against heat, such as carbon black powder, may be used.

The image forming medium 1 has a dielectric layer formed on a conductive substrate, as shown in FIG. 2, so as to be able to retain the electrostatic charge applied by the electrostatic image forming means 2.

FIG. 2 is an enlarged sectional view of a main part of an embodiment of the present invention, in which 11 is a conductive substrate and 12 is a dielectric layer. The conductive substrate 11 is generally a support made of metal, and has a drum shape, a belt shape, etc. The dielectric layer 12 is made of fluororesin in this embodiment, but of course, the dielectric layer may be made of ceramics or the like. It is also possible to use an inorganic material, an organic material such as a resin, or in special cases a photosensitive material such as amorphous silicon, and coat the dielectric layer with a fluororesin.

As the electrostatic image forming means 2, an electrostatic recording head such as a multi-stylus or an ion current modulation head, or a xerographic process can be used when the above-mentioned photosensitive dielectric layer is used.

As the developing means 3, means such as one-component development, two-component development, etc. that have been used in the conventional field of xerography can be used. However, in the recording method of the present invention, since development is performed by bringing the developer close to or in contact with the heated image forming medium 1, members including the developer conveying means must be made of sufficiently heat-resistant materials. be.

In conventional thermal transfer recording methods, in order to prevent the toner from thermally blocking in the developing means due to heat from the transfer section, the temperature of the developing means is kept as low as possible.
Measures for cooling and thermal isolation have been taken, but in the thermal transfer recording method of the present invention, if the above-mentioned microcapsule toner is used, there is almost no concern about thermal blocking as long as the temperature is below the glass transition point of the outer shell material.

As the transfer means, an elastic roll having a heat-resistant rubber material on the outer periphery, such as that used in conventional xerographic heat fixing devices, can be used. In the transfer area, the toner image on the image forming medium 1 comes into contact with the recording medium 7 and is subjected to pressure, the outer shell of the toner is destroyed, the core material inside flows out, and the recording is mainly caused by the adhesiveness of the core material. transferred to a medium. In order to utilize the effect of pressure more effectively, a roll with a high elastic modulus or a nearly rigid roll may be used as the transfer means.

In the transfer process, it is important to increase the ratio of toner transferred to the recording medium as much as possible (and to minimize the amount of toner remaining on the image forming medium. If the transfer rate is low, This causes many problems such as insufficient image density, unnecessary waste of toner, increased burden on cleaning means, and dirt inside the machine.

In the present invention, a fluororesin is used as the dielectric layer of the image forming medium, and this fluororesin has good mold releasability and heat resistance, and is also excellent in electrical properties such as insulation and dielectric constant. The fluororesin can be selected from TFE (tetraral ethylene propylene), FEP (fluorinated ethylene propylene), PFT (perfluoroalkoxy), Teflon 7, PVF (tetra-TI'I), and the like.

To create an image forming medium, a film-like fluororesin is pasted or wrapped around a conductor substrate such as a metal, or the surface of the conductor substrate is finished to a roughness of a few microns by sandblasting, etc., and then the fluororesin is thermally sprayed and then polished. For example, (a)
A 30μ thick PFA film may be wrapped around an aluminum pipe and the ends may be heat-sealed, or (b) PFA may be thermally sprayed onto a copper pipe finished to an average roughness of 3μ and then pub-polished to a thickness of 30/7.

To improve transferability, in addition to coating the surface of the image forming medium with a low surface energy material such as fluororesin as described above,
It is also extremely important to include a releasable resin material with low surface energy and low surface tension, such as polyolefin wax, in the toner.

When using a microcapsule toner in the present invention, it is preferable to include the releasable resin material in the core material from the viewpoint of preventing thermal blocking.

〔Effect of the invention〕

As described above, according to the present invention, transferability can be improved by coating the surface of an image forming medium with a fluororesin and incorporating a releasable resin material into the constituent materials of the toner. .

[Brief explanation of drawings]

FIG. 1 is a diagram showing an embodiment of the thermal transfer recording method of the present invention;
FIG. 2 is an enlarged view of the main part of FIG. 1, and FIGS. 3 and 4 are diagrams showing an example of a conventional thermal transfer recording apparatus. DESCRIPTION OF SYMBOLS 1... Image forming medium, 2... Electrostatic image forming means, 3...
...Developing means, 4...Heating means, 5...Transfer means,
6... Toner image, 7... Recording medium 11... Conductor substrate, 12... Dielectric layer. Applicant Fuji Xerox Co., Ltd. Agent Patent Attorney Masanobu Hirukawa (2 others) Figure 4
Figure 3

Claims (2)

[Claims] (1) By forming an electrostatic latent image on an image forming medium, developing the electrostatic latent image with toner to form a toner image, and bringing the toner image into contact with the recording medium while being heated by a heating means. 1. A thermal transfer recording method for transferring a toner image, the method comprising: coating at least the surface of an image forming medium with a fluororesin; and incorporating a releasable resin material into the constituent materials of the toner. (2) The toner is a microcapsule toner comprising an outer shell made of a material having a relatively high glass transition point and a core material made of a material having a glass transition point lower than that of the outer shell material. The thermal transfer recording method according to item 1.