JPS6277985A - Transfer recording medium - Google Patents

Abstract

PURPOSE:To enable high-quality images to be transferred onto an ordinary paper and enable high-speed recording, by incorporating a photo-reactive component and a coloring material in a transfer recording layer and arranging the transfer recording layer so that it is converted into a liquid phase having a viscosity not more than a specified value when being heated. CONSTITUTION:On a base is provided a transfer recording layer which is in a solid phase at normal temperature, comprises at least a photo-reactive component and a coloring material, and is converted into a liquid phase having a viscosity of not more than 1,000cpis when being heated. A thermal recording medium 1 is supplied with heat pulses from a thermal head 4, and is simultaneously irradiated with light from a lamp 3. The part of the transfer recording layer 1a which is heated and irradiated with the light is hardened, resulting in a rise in melting temperature, whereas an unhardened part forms a transfer image. The transfer image is transferred onto a transfer recording medium 10 by a heated roll 8 and a pinch roll 9. Since fluidity is rapidly provided at a predetermined temperature, the polymerization or cross-linking reaction of the photo-reactive component proceeds in a short time. Accordingly, by applying optical energy and thermal energy, a transferred image can be obtained at high speed.

Description

DETAILED DESCRIPTION OF THE INVENTION <Field of Industrial Application> The present invention relates to a novel transfer recording medium that can be used in copying machines, facsimile machines, printers, and the like.

<Conventional techniques> Recently, 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 also been developed and adopted. As one such recording method, the thermal transfer recording method has recently been widely used because the apparatus used is lightweight, compact, noiseless, and has excellent operability and maintainability.

This thermal transfer recording method generally uses a thermal transfer medium formed by coating a sheet-like support with a thermal transfer ink made of a heat-melting binder and a colorant dispersed therein. The thermal transferable ink layer is superimposed on the transfer medium so as to be in contact with the transfer medium, and heat is supplied from the support side of the thermal transfer medium by a thermal head to transfer the melted ink layer to the transfer medium. A transfer ink image is formed on a medium according to the shape of heat supply. According to this method, plain paper can be used as the transfer medium.

However, conventional thermal transfer recording methods are not without drawbacks. This is because in the conventional thermal transfer recording method, the transfer recording performance, that is, the print quality, is greatly affected by the surface smoothness.Good printing is performed on highly smooth transfer media, but on less smooth transfer media. In some cases, the print quality deteriorates significantly. However, even when paper, which is the most typical transfer medium, is used, paper with high smoothness is rather special, and ordinary paper has various degrees of unevenness due to intertwining of fibers. Therefore, in the case of paper with large surface irregularities, the hot-melted ink cannot penetrate into the paper fibers during printing and only adheres to the convexities on the surface or the vicinity thereof, resulting in sharp edges of the printed image. The image may be missing, or part of the image may be missing, resulting in a decrease in print quality.

In addition, the transfer of the ink layer to the transfer medium is performed only by heat from the thermal head, but the amount of heat supplied from the thermal head is generally limited, and a large amount of recording can be done in a limited short period of time. In order to exchange signals as thermal pulses, the thermal head must be cooled to a predetermined temperature between the thermal pulses during recording, and furthermore, in order to prevent thermal crosstalk between the heat generating segments that make up the thermal head surface. Theoretically, it is difficult to increase the amount of heat supplied from the thermal head. Therefore, high-speed recording is difficult with conventional thermal transfer recording methods.

In addition, since thermal conduction has a slower response than electricity or light, it is generally difficult to control the heat pulse to the extent that halftones can be reproduced when recording with a thermal head, and conventional thermal transfer Since the ink layer does not have a gradation transfer function, it was not possible to record halftones.

<Purpose of the Invention> The present invention has been made to solve the above-mentioned problems of the conventional art. The main object of the present invention is to provide a transfer recording medium that is capable of forming images, high-speed recording, and halftone recording.

Means for Solving the Problems> The present invention has a transfer recording layer that is solid at room temperature on a base material, the transfer recording layer contains at least a photoreactive component and a coloring material, and the transfer recording layer contains at least a photoreactive component and a coloring material. When the recording layer is heated, the transfer recording layer becomes a liquid phase with a viscosity of 1000 cpis or less.

That is, in the image forming method using the transfer recording medium of the present invention,
The transfer image formation and the transfer process are separated, and in the transfer process, the transfer image has already been formed, so there is no need to apply image-wise selective energy, and a clear image can be transferred depending on the surface properties of the transfer medium. The transfer recording medium can be provided with the energy necessary to form the transfer recording medium. In addition, the transferred image formed as a pre-process is not a mere property-change image such as a heat-fused image, but an image formed by changing the physical properties that govern the transfer characteristics, so the difference in the physical properties before and after the change is reflected in the transfer process. By using this method, transfer can be achieved reliably, and the transferred image can also be faithfully transferred. For example, when a thermally fused image is used as a transferred image, it is desirable to maintain the thermally fused image completely from the transfer image formation process to the transfer process. Blurring of the image due to heat conduction to the surroundings is unavoidable. However, in the case of the present invention, the physical properties that govern the transfer characteristics, such as the melting point, softening point, and viscosity at the same temperature of the transfer recording layer, can be image-formed. Since the transferred image is made by changing the physical properties, this physical property change is memorized until the transfer process, and unless energy is applied to change the physical properties after the transfer image forming process, the transferability of the transferred image may deteriorate, Image blur does not occur. Therefore, even if the surface smoothness of the transfer medium is low, it is possible to form a high-quality image, and it is also possible to transfer the transferred image to the transfer medium without deteriorating the image quality. It is something that can be done.

Furthermore, in the image forming method according to the present invention, the application of signalized energy for forming a transferred image and the application of uniform energy for transfer are functionally separated. Compared to the case where the signaled energy must be simultaneously used as energy for transfer, the conditions for energy application are relaxed, e.g.
The amount of energy for forming a transferred image only needs to cause a change in the physical properties of the transfer recording layer, and the energy for transfer can be uniform energy that is not converted into a signal, so it can be adjusted to the desired transfer speed. It is possible to increase the recording speed by increasing the recording speed, and high-speed recording can be easily realized.

In addition, the thermal response speed of the thermal heads used in conventional thermal transfer recording devices is 1 to 5 ms even for the fastest one.
c. If you try to drive with a repeated cycle that is more than that, the temperature will not rise or fall sufficiently within one cycle, resulting in insufficient heating or, conversely, the temperature will not drop completely and the effect of heat storage will occur. It appears in the image quality. This was one of the biggest factors that hindered speed-up, but if, for example, a thermal head and light irradiation are combined as in the present invention, even if heat accumulates, the heating state is effective only during light irradiation. Therefore, by irradiating light only during a limited time period near the peak temperature, it is possible to make it less susceptible to the temperature drop rate after the peak temperature as in the past, and even when using a conventional thermal head. Since the recording operation can be performed at a shorter repetition period, high-speed recording becomes easier.

Furthermore, since the image forming method according to the present invention forms a transferred image by applying multiple types of energy, compared to the conventional case of forming a transferred image using only heat, only one type of energy is required to form the transferred image. Because there are multiple types of energy, it is possible to adjust the degree of change in physical properties that form a transferred image step by step. Since other energies that are quick and easy to adjust stepwise in five intensities are also used, it is easy to form images with halftones.

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

Although it is desired that such control be performed at high speed, the ability to use energy with a quick response such as light also enables high-speed halftone recording.

The transfer recording medium of the present invention has a transfer recording layer that is solid at room temperature on a base material. The transfer recording layer on the base material has a property that when it is irradiated with light while being melted by heat, the melting temperature increases. Such a transfer recording medium of the present invention is used, for example, with the apparatus shown in FIG.

The apparatus shown in FIG. 1 selectively drives a single heating means 4 having a plurality of heating elements according to an image signal, and irradiates light onto at least the position of the driven heating element. , a transfer image is formed on the transfer recording layer 1a of the transfer recording medium 1 of the present invention. The transfer recording layer 1a on the base material 1b is irradiated with light while being melted by heat, so that its melting temperature increases. 2 is a supply roll around which the transfer recording medium 1 is wound;
3 is a light irradiation means such as a low-pressure mercury lamp, high-pressure mercury lamp, metal hacoid, fluorescent lamp, or xenon lamp for uniformly irradiating light onto the transfer recording medium l; 4 is a control circuit 5 based on the image signal;
This is a heating means such as a thermal head that generates heat pulses. This heating means 4 includes a plurality of heating elements. The heating elements may be arranged in a single row, in a matrix, or in multiple rows.

Further, the heating elements may be each separated, or may be a continuous rod-shaped current-generating heat generating material separated by a plurality of poles.

Reference numeral 8.9 is a transfer means, 8 is a heat roll having a heater 7 inside, and 9 is arranged opposite to the heat roll 8 to transfer a transfer medium 10 such as plain paper or an OHP sheet and a transfer recording medium 1. A pinch roller 11 is a winding roll that winds up the transfer recording medium 1 after transfer recording.

The recorded image 12 is formed on the transfer medium 10 and separated from the transfer recording medium 1 .

Now, the transfer recording medium 1, which has been fed out by the supply roll 2, is given a thermal pulse that is similar to the image signal by the thermal head 4. At the same time that a heat pulse is applied to the transfer recording medium 1 by the thermal head 4, light is irradiated from the wrap 3.

The portion of the transfer recording layer 1a that is irradiated with heat and light is hardened and its melting temperature increases. As a result, a transferred image is formed by the uncured portions. This transferred image is transferred onto the transfer medium IO by the heat roll 8 and the pinch roller 9.

The transfer recording layer 1a of the uninvented transfer recording medium 1 contains at least a photoreactive component and a coloring material. The photoreactive component refers to a component that is polymerized by photocrosslinking or photopolymerization, and includes, for example, a prepolymer having a photoreactive group, as will be explained in detail later.

In the transfer recording medium of the present invention, the transfer recording layer is in a solid phase at room temperature, but has the property of rapidly becoming fluid at a predetermined temperature when heated. As the transfer recording layer suddenly exhibits fluidity, the degree of freedom of the photoreactive component increases, and by being irradiated with light in this state, the polymerization and crosslinking reaction proceeds in a very short time. In this way, the areas irradiated with heat and light are cured, and the areas not irradiated with heat and light form a transferred image.

In order to form a transferred image in a very short time like this,
When heat is applied, the transfer recording layer changes from a solid phase to a viscosity of 1000c.
It is necessary to have a liquid phase below pis. In particular, the viscosity is 1000 cp when the temperature change is within 20 degrees, preferably within 5 degrees.
It is desirable that the liquid phase be less than or equal to i s. In addition, the temperature at which the transfer recording layer starts to melt is 50 to 180 degrees Celsius, preferably 70 to 180 degrees Celsius, in view of the practical use of heating means such as thermal heads.
00°C is preferred. In the present invention, the term "solid phase" refers to a phase in which the transfer recording layer can maintain its shape by itself, and therefore also includes a phase in a highly viscous liquid phase. Further, the viscosity is a value measured using a B-type viscometer.

As a transfer recording layer, for example, a) a polymerized acid prepolymer is used as a photoreactive component,
Consisting of a crosslinking agent, a photoinitiator, 1 binder.

) A polymerizable monomer or oligomer can be used as the photoreactive component, and a photoreaction initiator, binder, etc. can be used.

The polymerizable prepolymer has a polymerizable functional group in the main chain, the end of the main chain, or a side chain, and includes epoxy resins, unsaturated polyester resins, urethane resins, polyamide resins, silicone resins, and the like.

In addition, as crosslinking agents, polymerizable monomers, and oligomers,
Examples include monofunctional and polyfunctional methacrylates and acrylates.

As the photoreaction initiator, a radical generating source such as an azo compound, an organic sulfur compound, a carbonyl compound, or a halogen compound is used.

Now, the binder used has the property that the transfer recording medium of the present invention has, that is, it changes from a solid phase to a liquid phase with a viscosity of 1000 cpis or less when the temperature changes within 20 degrees, preferably within 5 degrees.

Polymer waxes that have such properties can be used, such as polyester polyols, full kylene copolymers such as polyethylene glycol, polypropylene glycol, and polytetramethylene glycol, phenolic resins, xylene resins, terpenes, and rosins. Can be mentioned.

Further, depending on the case, it is also possible to use the above-mentioned materials (a) and (b) without the binder. In this case, the polymerizable prepolymer, polymerizable monomer or oligomer itself must exhibit rapid fluidity. It should be something like this. Examples of such polymers include those in which the terminal hydroxyl group of an alkylene copolymer is substituted with a polymerizable functional group such as urethane acrylate or epoxy acrylate.

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 carbon black, yellow lead, inorganic pigments such as molybdenum red red red, Hansa yellow, benzidine yellow, brilliant carmine 6B, lake red C, permanent red F5R,
Organic pigments such as Phthalocyanine Blue, Victoria Blue Lake, Fattos Sky Blue, Kayaset Blue, etc.
Examples include colorants such as leuco dyes and phthalocyanine dyes.

In the present invention, the thickness of the transfer recording layer is preferably 3 to 20 mm, more preferably 5 to 10 mm thick.

The transfer recording layer may be in the form of a continuous film, or
The materials described in (a) and (i) above may be encapsulated and arranged uniformly on the base material. As the base material, polyethylene terephthalate, polyimide, and other base materials used in conventional transfer recording media can be used.

In addition, in the transfer recording medium of the present invention, a coloring agent exhibiting a plurality of color tones is used, the transfer recording layer is encapsulated or granulated, and a reaction initiator that exhibits a plurality of color tones is used. Color recording is also possible by using something with wavelength selectivity.

Furthermore, additives may be mixed into the transfer recording layer in order to improve storage stability before and after recording, transfer characteristics, and the like.

The operation of the present invention explained above will be explained in more detail using FIG. 2. Here, the polymerization reaction caused by the photoinitiator I, the crosslinking agent C, and the polymerizable prepolymer P is shown. FIG. 2a) shows that the probability that the photoreaction initiator (2) becomes the activated state Iφ upon being irradiated with light is almost constant regardless of the temperature. Figure 2 b) shows how the probability of reacting with C to form the activated crosslinking agent C, and Figure 2 C) shows how the probability of polymerizing the polymerizable prepolymer increases rapidly at temperatures above Tmc. show. This is T as shown in Figure 2b).
This is because the fluidity of the entire system suddenly increases at mc, and the reaction rate increases rapidly above Tmc, as shown in Figure 2 e). For the same reason, the probability that the activated crosslinking agent C. and the polymerizable prepolymer P will react and crosslink increases rapidly above Tmc.

Therefore, simultaneous irradiation with light and heating above Tmc form a crosslinked polymer product in a short time.

Example 1 A 6μ thick recording layer composed of the components shown in Table 1 was
It was placed on a μ-thick polyethylene terephthalate, rolled, and assembled into the apparatus shown in FIG.

Table 1 Using a thermal head of A-4 size line type with 8 dots/mm and a row of heating elements arranged at the edge part, the substrate side of the transfer recording medium is placed on the heating element, and the transfer recording is performed. It was arranged so as to be in contact with the medium, and was pressed against the heating element by the tension of the transfer recording medium. Then, at the opposite location, 2 cm away from the transfer recording medium, approximately 2 Kv is applied.
Place high-pressure mercury lamps
did .

Next, the heat generation of the thermal head is controlled according to the image signal.

In this case, negative recording is performed because the transfer recording layer is exposed to light and heat to raise its glass transition point. That is, the thermal head is controlled such that it does not conduct electricity when a mark signal (black) is present, but conducts current when it is not a mark signal (white) to generate heat. The energizing energy during this heat generation is 0.8 w/dot x2. O
ms e c.

It is. In this way, the thermal head is controlled and driven according to the image signal in the manner described above while uniformly irradiating light with a high-pressure mercury lamp, and the transfer recording medium is synchronously transferred with the stepping motor at a repeating cycle of 5 msec/line. It was transported using a drive rubber roll. After the transfer image was formed in this manner, plain paper with a surface smoothness of 10 to 30 seconds was placed on the transfer image surface, and the paper was sandwiched between a heat roll and a pinch coll and cut. The heat roll was an aluminum roll having a 300 W heater inside and whose surface was coated with silicone rubber 2 mm thick, and the heater was controlled to maintain the surface at 90 to 100°C. The pinch roll is a silicone rubber roll with a hardness of 50℃.
The IN was set at 1.5 kg/cm2. In this way, the image obtained on plain paper was clear, and a high-quality image with good fixability could be obtained.

Example 2 A recording layer having a thickness of 6 l and composed of the components shown in Table 2 was provided on a polyethylene terephthalate having a thickness of 6 l.

Table 2 Using this transfer recording medium, a transfer image was formed on plain paper in the same manner as in Example 1. However, in Example 2, the temperature of the heat roll was maintained at 70 to 80°C. The image thus obtained was 1 g bright and of high quality with good fixability.

Effects of the Present Invention The transfer recording medium of the present invention exhibits excellent fluidity at a predetermined temperature, so that the polymerization and crosslinking reactions of the photoreactive component proceed in a very short time. Therefore, according to the transfer recording medium of the present invention, a transfer image can be obtained at high speed by applying light and heat energy.

In the present invention, a transfer recording medium whose properties differ only when light and heat energy are applied at the same time is used. Compared to methods using transfer media that change characteristics, it has higher environmental stability.
It becomes possible to always stably obtain high-definition images. Furthermore, for this reason, the storage stability of the transfer recording medium is improved.

In addition, for example, when using only heat, the recording speed is controlled by the responsiveness of the system, and it takes a long time to apply the energy necessary for image formation to the transfer recording medium using only one energy source. In contrast, the transfer recording medium of the present invention is suitable for high-speed recording because it is controlled by light and heat energy.

Furthermore, since the transferred image is formed using light and heat energy, it is easy to adjust the degree of change in physical properties for forming the transferred image in stages, thereby making it possible to record halftones.

In addition, since the process of forming a transferred image and the process of transferring it are independent, the conditions suitable for transferring the transferred image to the transfer medium in a high quality and stably are determined independently of the conditions for forming the transferred image. Can be set freely. Therefore, it is possible to obtain high-quality images not only on plain paper, but also on paper with low surface smoothness and transparent range-equal height range media.

At the same time, excellent fixing properties can also be obtained.

[Brief explanation of drawings]

Fig. 1 is a schematic diagram showing an example of an apparatus using the transfer recording medium of the present invention, and Fig. 2 a), b), c), d), and e) are diagrams for explaining the operation of the transfer recording medium of the present invention. This is a graph of 1-------1 transfer recording medium 3-----1 light irradiation means 4--1--heating means 10--1 transfer medium 12--1 recording image

Claims (1)

[Claims] In a transfer recording medium having a transfer recording layer that is solid at room temperature on a base material, the transfer recording layer includes at least a photoreactive component and a coloring material, and when the transfer recording layer is heated, the transfer recording layer A transfer recording medium characterized in that the liquid phase has a viscosity of 1000 cpi or less.