JPS6292891A - Image-forming method - Google Patents

Abstract

PURPOSE:To enable recording at high speed and to record intermediate gradations, by supplying a transfer recording medium with many kinds of energy under conditions according to recording information, thereby forming a transferrable image, and transferring the transferrable image to a transfer recording material. CONSTITUTION:A transfer recording medium 1 paid out from a payout roll 2 and a recording paper 10 are fed by feeding rollers to a transferring part consisting of a heater 14 for heating the medium 1 one line at a time and a pressing member 13 formed of a quartz glass. One line on the transfer recording medium 1 is heated by the heater 14 controlled by a heating controller 15, and simultaneously, the heated line part of the medium 1 is irradiated with UV rays from a high-pressure mercury vapor lamp 3. The transfer recording medium 1 and the recording paper 10 are fed by such an amount that the next line is bought to the position of the heater 14. These steps are continuously carried out, whereby an image-forming material made to be fluid is adhered to the paper 10, and a desired clear black image can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a novel image forming method that can be used in copying machines, facsimile machines, printers, and the like.

[Prior Art] In recent years, with the rapid development of the information industry, various information processing systems have been developed, and recording methods and devices suitable for each information processing system have been developed. One of them is the thermal recording method, which has been widely used recently because the equipment used in this method is lightweight, compact, noiseless, and has excellent operability and maintainability.

Among these thermal recording methods, a thermal transfer recording method has recently attracted particular attention. This recording method is generally
A heat-sensitive transfer medium is used, in which a heat-transferable ink consisting of a colorant dispersed in a heat-melting binder is coated on a sheet-like support, and the heat-transferable ink layer is applied to the transfer medium. superimpose it on the transfer medium so as to touch it,
By supplying heat with a thermal head or the like from the support side of the thermal transfer medium and transferring the melted ink layer to the transfer medium, a transferred recorded image corresponding to the heat supply pattern is formed on the transfer medium. . According to this method, plain paper can be used as the transfer medium.

[Problems to be Solved by the Invention] However, in the conventional thermal transfer recording method, the ink layer is transferred to the transfer medium only by heat from the thermal head; There is a limit to the amount of heat that can be supplied, and in order to convert and supply a large amount of recording signals as heat pulses within a limited time, there is a time lag for the thermal head to cool down to a predetermined temperature between heat pulses during recording. Furthermore, it has been theoretically difficult to increase the amount of heat supplied from the thermal head in order to prevent thermal stroke between the heat generating segments that constitute the thermal head surface. Therefore, high-speed recording is difficult with conventional thermal recording methods.

In addition, thermal conduction has a slower response than electricity or light, so when recording with a thermal head, it is generally difficult to control heat pulses to the extent that halftones can be reproduced. The heat-sensitive transfer ink layer did not have transfer characteristics capable of expressing gradation, so it was not possible to form a half-tone recorded image.

The main object of the present invention is to provide a novel image forming method that solves the above-mentioned conventional problems, that is, an image forming method that is capable of high-speed recording and halftone recording.

[Means for Solving the Problems] The above object of the present invention is to provide a transfer recording medium having a transfer recording layer whose physical properties governing the transfer characteristics change when a plurality of types of energy are applied thereto. This is achieved by an image forming method in which a transferred image is formed and the transferred image is transferred to a transfer medium by applying the plurality of types of energy under the condition that at least one type of energy is applied in accordance with recorded information. .

That is, the present invention is capable of changing the physical properties that govern transferability, such as softening point and melt viscosity at a certain temperature, when multiple different energies are applied, such as light and heat, light, heat, and pressure, and heat and pressure. Forming a transferred image by applying at least one of the two or more different energies according to recorded information and other energy to a transfer recording medium having a changing recording layer, and This is a method of obtaining an image by transferring it to a transfer medium such as recording paper.

Image formation according to the present invention is performed, for example, by applying light and heat as follows.

In other words, when the recording paper is brought into close contact with the transfer recording medium, the area of the transfer recording layer where the transferred image is to be formed is heated, and then the area that is irradiated with light is irradiated with light that is controlled based on the transferred image, the area that is irradiated with light is cured. The remaining portions are melted by heating and adhere to the recording paper, and when the transfer recording medium is peeled off from the recording paper, an image is formed on the recording paper.

In the above case, heat was used as a means to bring the transfer recording layer into a transferable state, and light was used as a means to form a transfer image, but in the present invention, light brings the transfer recording layer into a transferable state. and a means for forming a positive transfer image, and a means for transferring a transfer recording layer by using other energy such as pressure instead of heat or in combination. It also includes those that form a state or form a positive transfer image. Further, depending on the apparatus, the step of making the transfer recording layer ready for transfer and the step of forming a positive transfer image may be time-shifted.

By using the image forming method of the present invention, high-speed recording becomes possible. In the thermal heads used in conventional thermal transfer recording devices, even the fastest thermal response speed is 1~
5m5ec, and if you try to drive it at a faster repetition cycle, the temperature will not rise or fall sufficiently within one cycle, resulting in insufficient heating or, conversely, the temperature not falling completely, resulting in heat storage. Shadows appeared in the image quality. This was one of the biggest factors hindering speed-up, but if multiple types of energy are used as in the present invention, for example by combining a thermal head and light irradiation, the transfer characteristics can be controlled even under heat-accumulated conditions. The effectiveness of the heating state in changing the physical properties of the material can be limited to the time of light irradiation.
By irradiating light only during a limited time period around the peak temperature, it is possible to make it less susceptible to the temperature drop rate after the peak temperature, which is the case with conventional methods, even if a conventional thermal head is used. , the recording operation can be performed at a shorter repetition period, and high-speed recording becomes easier.

In addition, since the image forming method according to the present invention transfers and records by applying multiple types of energy, it is possible to gradually change the degree of physical property change during transfer and recording, compared to the conventional case of transfer and recording using only heat. By using light, which can be adjusted to a certain level, has a quick response as one of multiple types of energy, and whose intensity can be easily adjusted stepwise, it becomes easier to form images that require halftone expression.

For example, by setting the intensity or time of light irradiation in three stages and combining it with heating, it becomes possible to express gradations in four stages (three stages + non-heating).

Furthermore, it is desirable that such control be performed at high speed, and the ability to use energy with a quick response such as light is also one of the factors that makes high-speed halftone recording possible.

In the image forming method according to the present invention, the transferred image is formed by changing the physical properties that govern the transfer characteristics of the image forming element, but these physical properties are arbitrarily determined depending on the type of transfer recording medium used. For example, in the case of a transfer recording medium that transfers a transferred image in a thermally molten state, the melting temperature,
It is the softening temperature or the glass transition point, and in the case of a transfer recording medium in which the transferred image is transferred in an adhesive state or a permeable state to the transfer medium, it is the viscosity at the same temperature.

Furthermore, the plurality of types of energy used for transfer recording can also be arbitrarily determined depending on the type of transfer recording medium used. for example,
Light, electron beam, heat, pressure, etc. are used in appropriate combinations.

Next, in order to understand the transfer recording of the present invention, an example using a transfer recording medium on which a transferred image is formed by light and thermal energy will be explained with reference to FIGS. 5a to 5c. Fifth
The time axes (horizontal axes) of the graphs in FIGS. d to 5c correspond to each other. In addition, as a sensitive component in the transfer recording layer,
It contains polymerization components including a reaction initiator and a crosslinking agent, which will be described later. FIG. 5a shows the rise in surface temperature of the heating element and subsequent temperature drop when the heating means that uniformly heats only one line is driven to develop heat from time 0 to t3. The transfer recording layer that is in pressure contact with this heating element exhibits a temperature change as shown in FIG. 5b as the temperature of the heating element changes, that is, the temperature rises with a time delay of tl, and similarly with a delay of t3. The maximum temperature is reached at time t4, and the temperature decreases thereafter. This transfer recording layer has a glass transition point Tgo, and is rapidly softened and its viscosity decreases in a temperature range above Tgo. This situation is shown by curve A in FIG. 5C. After reaching Tgo at time L2, the viscosity continues to decrease until time t4 when the temperature reaches the maximum, and as the temperature decreases, the viscosity increases again, and rapidly increases until time t6 when it decreases to Tgo. In this case, the physical properties of the transfer recording layer are basically unchanged from those before heating, and the same viscosity change phenomenon as described above occurs only when heated above the temperature Tgo. Heat required for pressure contact and transfer, for example Tg.

If the heating is performed above, the transfer recording layer will be transferred by a mechanism similar to that of conventional thermal transfer recording. However, in the case of the present invention, as shown in FIG. 5c, when the transfer recording layer is heated and irradiated with light from time t2, the reaction initiator contained in the transfer recording layer is activated by the light irradiation. When the temperature is raised sufficiently to increase the reaction rate, the reaction initiator acts to form an activated crosslinker, which dramatically increases the probability of crosslinking the crosslinkable prepolymer. becomes larger, and the hardening of the transfer recording layer progresses.

When heating and light irradiation are performed simultaneously in this manner, the transfer recording layer exhibits a behavior as shown by curve B in FIG. 5c. As the crosslinking reaction progresses, the glass transition point rises, and at time t5 when crosslinking ends, Tg.

to Tg'. Therefore, the period during which there are parts where the viscosity has decreased and parts where it has not decreased, that is, from t2 to
However, if the portion is pressed against the transfer medium during this period, only the portion whose viscosity has decreased will be transferred onto the transfer medium. Although it depends on the temperature stability accuracy during transfer, Tg' Tgo at this time
is preferably about 20°C or higher. A transferred image can be formed by controlling heating or non-heating in this manner and simultaneously irradiating light according to an image signal. Furthermore, if the glass transition point changes, the softening temperature and melting temperature also change in a similar manner, so the softening temperature and melting temperature can be controlled using the fluctuation range of the glass transition point as a guide.

As the transfer recording medium used in the present invention, any transfer recording medium can be used as long as it can form a transferred image by changing physical properties due to a plurality of types of energy. For example, a transfer recording medium containing a coloring component and a polymerized component as a sensitive component in an image forming element can be cited as one that changes physical properties such as the above-mentioned melting temperature, softening point, glass transition point, and viscosity. By polymerizing the polymerized component, the melting temperature, etc. of the transfer recording layer in that portion increases, and the portion that is not polymerized forms a transferred image.

The polymerization component is a component that causes a polymerization reaction or a crosslinking reaction, and typical examples thereof include the following monomers or polymers (a) to (c).

(a) Crosslinkable prepolymer.

0) Polymerizable prepolymer and crosslinking agent, (c) Normally polymerizable monomer or oligomer, Examples of the crosslinkable prepolymer include polyvinyl cinnamate, p-methoxycinnamic acid-succinic acid half ester, polyvinylstyrylpyridium , polymethyl vinyl ketone 1, copolymers of methyl vinyl ketone, methyl impropetul ketone, and ethylene or styrene, polysulfone, and the like.

Examples of the polymerizable prepolymer include epoxy resin, unsaturated polyester resin, polyurethane resin, polyvinyl alcohol resin, polyamide resin, polyacrylic acid resin, polymaleic acid resin, and silicone resin.

Examples of the crosslinking agent include ethylene glycol diacrylate, propylene glycol diacrylate, ethylene glycol dimethacrylate, 1,4-butanediol diacrylate, and N,N'-methylenebisacrylamide.

Examples of polymerizable monomers include methyl acrylate,
Methyl methacrylate, cyclohexyl acrylate,
Benzyl acrylate, acrylamide, methacrylamide, N-methylol acrylamide, N-diacetone acrylamide, styrene, acrylonitrile, vinyl acetate, ethylene glycol diacrylate, butylene glycol dimethacrylate, 1.4-butanediol diacrylate, 1.6 -hexanethiol dimethacrylate and the like.

Examples of the polymerizable oligomer include diethylene glycol diacrylate, triethylene glycol diacrylate, polyethylene glycol acrylate, polyethylene glycol dimethacrylate, and polypropylene glycol diacrylate.

When a polymerizable monomer or oligomer is used, a polymer such as cellulose acetate succinate or methyl methacrylate-hydroxyethyl methacrylate copolymer may be included in order to improve layer-forming properties.

A reaction initiator is added as necessary to cause the polymerization component to react. Examples of initiators that act with light energy include benzophenone, benzyl, pentwinethyl ether, 4-N,
Carbonyl compounds such as N-dimethylamino-4'-methoxy-benzophenone; Organic sulfur compounds such as nidibutyl sulfide, pencil disulfide, and decylphenyl sulfide; ';' -tert-butyl peroxide, pentyl peroxide, etc. Peroxides; halogen compounds such as carbon tetrachloride, silver bromide, and 2-naphthalenesulfonylglorite; nitrogen compounds such as azobisisobutyronitrile and benzenediazonium chloride F; and the like.

Examples of substances that act as reaction initiators upon receiving thermal energy include methyl hydroperoxide, t-butyl hydroperoxide, t-butyl peroxide, t-butyl cumyl peroxide, peroxyacetic acid, peroxybenzoic acid, acetyl peroxide, Examples include propionyl peroxide, imbutyryl peroxide, acetone peroxide, methyl ethyl ketone peroxide, diazoamine benzene, dimethyl-2,2'-azoisobutylade, diphenyl sulfide, benzoyl disulfide, and the like.

In particular, in the structure of the transfer recording layer when a transferred image is formed by receiving both light and thermal energy, the reaction rate is increased by the reaction between the reaction initiator and the polymerization component, which act in response to the above-mentioned light energy. In order to obtain a combination with large temperature dependence,
All you have to do is select the type of reaction initiator and polymerization component.

For example, a combination of a polymerizable prepolymer having a functional group such as a copolymer of methacrylic ester or acrylic ester, a photosensitive crosslinking agent such as tetraethylene glycol diacrylate, and a reaction initiator such as benzophenone or Michler's ketone. can be mentioned.

The coloring component is a component contained in order to form an optically recognizable image, and various pigments and dyes are used as appropriate. Examples of such pigments and dyes include inorganic pigments such as carbon blank, C4 lead, molybdenum red, and red iron.
Hansa Yellow, Benzidine Yellow, Brilliant Carmine 6B, Lakelet C, Permanent Red F5
R, Phthalocyanine Blue, Victoria Blue Lake,
Examples include organic pigments such as fast sky blue, colorants such as leuco dyes, and phthalocyanine dyes.

[Example] Next, examples of the image forming method of the present invention are shown in FIGS. 1 to 5a,
This will be explained with reference to Figures 5b and 5c.

Example 1 The compositions shown in Table 1 were melt-mixed to obtain an image-forming body whose softening point increases when irradiated with ultraviolet rays in a molten state.

This image forming body was melted and uniformly coated onto a polyimide film having a thickness of 6 mm to a thickness of 2 to 3 mm to obtain a transfer recording medium 1.

Using this transfer recording medium 1, an image was formed on recording paper (copy paper) 10 using a transfer recording apparatus as shown in FIG.

That is, the transfer recording medium 1 wound around the supply roll 2
A recording paper (copy paper) 10 is transferred to a transfer section, which is composed of a heater 14 that heats each line line by line, and a pressure bonding member 13 made of quartz glass, which is an ultraviolet-transparent substance, by a conveyance roller (not shown) as shown in FIG. Transported as shown. And the heating control system! Heater 1 controlled by η '15
4, one line of the transfer recording medium 1 was heated for 5 m5ec at +50'l:: At the same time, the heated line part of the transfer recording medium 1 was controlled by the control circuit 5 based on the image signal. 2 was irradiated with ultraviolet VJ (wavelength: 400) emitted from a high-pressure mercury lamp 3. After this heating and ultraviolet irradiation, the transfer recording medium 1 and the recording paper 10 were conveyed to the next line at 20 msec by a stepping motor and a drive roller (not shown). This (5+
20) When the msec process was performed continuously, the image forming material, which had a low glass transition temperature, that is, the viscosity decreased and became a fluid state, adhered to the recording paper 10 except for the portion where the softening point increased due to light irradiation. , the desired clear black image was obtained. Further, the transfer recording medium 1, which had undergone the image forming process, was peeled off from the recording paper 1O and wound up on the winding roll 11, with the untransferred image forming body remaining.

Example 2 An image was formed by replacing the heater 14 in the apparatus of Example 1 with a heat roll 8 as shown in FIG. At this time, image formation was performed in the same steps as in Example 1, except that the transfer recording medium 1 was moved by the rotation of the heat roll 8 instead of conveying the recording paper 10 by a roller (not shown). In this method, the peeling shaft 21 is located at the position shown in FIG. 4, and the transfer recording medium 1 is peeled off from the recording paper 10 after a period of time has elapsed after the transfer image is formed by ultraviolet irradiation. A clear image similar to that was obtained.

Example 3 The compositions shown in Table 2 were melt-mixed to obtain an image-forming body that softens when heated and irradiated with ultraviolet rays.

This image-forming body was melted and uniformly coated on a polyimide film having a thickness of 6 μs to a thickness of 2 to 3 cm to obtain a transfer recording medium 1. Using this transfer recording medium 1, the second
Recording paper (copy paper) 1 with a transfer recording device as shown in the figure.
An image was formed on 0.

That is, the transfer recording medium 1 wound around the supply roll 2
and recording paper (copy paper) 10 are conveyed by a conveyor roller (not shown), and the surface is heated to 90 to 90 degrees by an internal heater 7 of 300 mm.
As shown in FIG. 2, the sheet was conveyed to a transfer section comprised of a heat roll 8 kept at 100.degree. C. and a pressure bonding member 13 made of quartz glass, which is an ultraviolet-transparent material. Then, as shown in FIG. 2, the portion of the recording paper 10 in contact with the heat roll 8 was heated to 90 to 100° C. for 5111 seconds. At the same time, ultraviolet rays (wavelength 450 μs) emitted from a 2kW high-pressure mercury lamp 3 were irradiated to the portion of the transfer recording medium 1 that was in contact with the heated recording paper 1o under control based on the image signal by the control circuit 5. . After this heating and ultraviolet irradiation, the transfer recording medium 1 and the recording paper 10 were conveyed to the next line at 20 msec by a stepping motor and a drive roller (not shown). This (5+
20) When the msec process was performed continuously, the softened portion of the image forming body due to light irradiation and heating adhered to the recording paper 10, and a desired clear black image was obtained. Further, the transfer recording medium 1 that had undergone the image forming process was peeled off from the recording paper 10 and wound onto a winding roll 11 with the untransferred image forming body remaining.

Embodiment 4 Furthermore, as shown in FIG. 5 using the apparatus of Embodiment 3, ultraviolet rays were applied to the transfer recording medium 1 at a point where the suppression by the heat roll 8 was small, before the suppression reached the level necessary for transfer. When irradiated and a transferred image was formed, a clear image similar to that of Example 3 was obtained.

Table 2 Composition Table [Effects of the Invention] As mentioned above, in the present invention, a transfer recording medium with different properties is used only when multiple types of energy are applied at the same time, so it does not affect the environmental temperature as it did in conventional methods. Compared to methods that use only the heat received or methods that use a transfer recording medium whose characteristics change due to light energy alone, this method has higher environmental stability, making it possible to consistently obtain high-definition images. Furthermore, for this reason, the storage properties of the transfer recording medium and the storage properties of recorded images have been improved.

In addition, for example, in a method that uses only heat, the recording speed is controlled by the thermal reactivity of the system, and conventional methods require a large amount of time to apply the energy necessary for image formation to the transfer recording medium using only one energy source. Regarding the method, the present invention is suitable for high-speed recording due to the control with two or more energies.

Furthermore, since transfer recording is performed using a plurality of types of energy, it is easy to adjust the degree of change in transfer physical properties step by step, and halftone recording can be performed.

Furthermore, in the present invention, since the transfer characteristics change according to the image information of the transfer recording medium and the transfer of the corresponding portion to the transfer medium are performed simultaneously, the configuration of the recording apparatus can be simplified by using the Motoyama image forming method. Become. Therefore, it is possible to downsize the device and contribute to improved reliability.

[Brief explanation of drawings]

1 and 2 are cross-sectional views of a transfer recording apparatus used in carrying out the present invention, FIG. 3 is an enlarged cross-sectional view showing the transfer process of Example 4, and FIG. FIG. 3 is an enlarged cross-sectional view showing the transfer process of FIG. FIG. 5a is a graph showing changes in the surface temperature of the heating element during one cycle of the transfer process of the present invention, and FIG. 5b is a graph showing the surface temperature of the transfer recording layer during one cycle of the transfer process of the present invention. FIG. 5c is a graph showing changes in temperature, and FIG. 5c is a graph showing changes in viscosity of the transfer recording layer during one cycle of the transfer process of the present invention. 1... Transfer recording medium 2... Supply roll 3... Lamp 4... Thermal head 5... Control circuit 7... Heater 8... Heat roller 10... Recording paper 11... - Winding roll 12... Recording screen 13... Ultraviolet transparent pressure bonding member 14... Heating device 5... Heating control circuit 20... Guide shaft 21... Peeling shaft A... Light Change in viscosity without irradiation B... Change in viscosity with light irradiation C... Heat generation time D... Light irradiation time E... l cycle time Patent applicant Canon Co., Ltd. Agent Wakabayashi Chu 1st figure 2nd figure 3rd figure

Claims (1)

[Claims] A transfer recording medium having a transfer recording layer in which the physical properties governing transfer characteristics change when multiple types of energy are applied, under the condition that at least one type of energy among the multiple types is applied in correspondence with recorded information. An image forming method comprising applying the plurality of types of energy to form a transferred image and transferring the transferred image to a transfer medium.