JPS63145304A - Photopolymerization initiator and recording medium - Google Patents

Abstract

PURPOSE:To form a photopolymerization initiator capable of accelerating photopolymerization of a photosensitive composition, by using with a specified compound and a sensitizer together. CONSTITUTION:The title photopolymerization initiator contains a compound of formula 1 and a sensitizer. In the formula 1, Ar<1> and Ar<2> are each an aromatic or heterocyclic compound which may have a substituent and in which the carbonyl group has a substituent other than hydrogen on at least one of its beta positions. Ar<1> and Ar<2> may be the same or different. The substituents which are substituted for a hydrogen atom at least one beta position of the carbenyl group include preferably an alkyl, alkoxy or hydroxyl group and a halogen atom. The sensitizer which is used together with the compound of formula 1 includes coumarin derivatives and aromatic compounds having a carbonyl group, such as styryl ketone derivatives having a monoalkylamino, dialkylamino, cyclic alkylamino or alkoxy group.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a photopolymerization initiator used in UV paints, printing inks, adhesives, photoresists, or components of recording media for transfer recording. be. The present invention also relates to a new recording medium used in recording devices such as printers, copiers, and facsimile machines, and particularly to a recording medium used in a recording method suitable for one-shot color recording.

[Conventional technology and problems]

Conventionally, there are photosensitive compositions containing photopolymerization initiators that are used as components in UV paints, printing inks, adhesives, photoresists, etc. It wasn't good enough.

In recent years, recording methods and devices suitable for various information processing systems have been developed and adopted, but thermal transfer recording methods are lightweight, compact, noiseless, and easy to operate and maintain. 1) and has been widely used recently. According to this method, plain paper can be used as the transfer medium.

However, conventional thermal transfer recording methods are not without drawbacks. The reason is that in conventional thermal transfer recording methods, the transfer recording performance, that is, the print quality, is greatly affected by the surface smoothness. Good printing can be performed on highly smooth transfer media, but on less smooth transfer media. In the case of media, the print quality deteriorates significantly. However, even when using paper, which is the most typical transfer medium, highly smooth paper is rather special (1), and ordinary paper has various degrees of unevenness due to entangled fibers. Therefore, according to the conventional thermal transfer recording method, the edges of the printed image are not sharp (1), and a portion of the image may be missing, which deteriorates the print quality.

In addition, in conventional thermal transfer recording methods, the ink layer is transferred to the transfer medium using only heat from the thermal head, but the thermal head must be cooled to a predetermined temperature within a limited short time. Furthermore, it is logically difficult to increase the amount of heat supplied from the thermal head because thermal crosstalk between the heat generating segments that make up the thermal head surface must be prevented. 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 thermal pulses to the extent that halftones can be reproduced when recording with a conventional thermal head1). Further, the conventional thermal transfer ink layer does not have a gradation transfer function, and therefore cannot perform halftone recording.

In addition, with conventional thermal transfer recording methods, it is possible to obtain only one color image with one transfer, so in order to obtain a multicolor image, multiple transfers are reversed to overlap the colors. It was necessary to match. However, it is very difficult to accurately superimpose images of different colors (1), and it is difficult to obtain images without color shift. In particular, when focusing on a single pixel, colors are rarely superimposed in a single pixel, and in the end, in conventional thermal transfer recording methods, multicolor images are created by aggregation of pixels with shifted colors. was forming. For this reason, clear multicolor images cannot be obtained using conventional thermal transfer recording methods.

In addition, when trying to obtain a multicolor image using a conventional thermal transfer recording method, it is necessary to install multiple thermal heads (1) or to make complicated movements such as reverse feeding and stopping of the transfer medium. There were drawbacks such as the overall size and complexity of the device (1) and a decrease in recording speed.

Further, US Pat. No. 4,399,209 discloses a system that uses a color forming agent and a color developer to form a multicolor visible image. U.S. Pat. No. 4,399,209 uses a recording medium in which microcapsules containing a photosensitive composition and a coloring agent are arranged on a base material, and uses mainly ultraviolet light converted in accordance with a recorded image to The photosensitive composition inside the capsule is cured to form a transferred image, and this transferred image is further superimposed on a recording medium having a color developer layer, and the microcapsule is destroyed by passing it through a nip between a pair of pressure rollers. The present invention also discloses a transfer image forming system that develops an image. A multicolor image is obtained by image-formingly transferring a color former to an image forming sheet, where the color former reacts to form an image.

Further, US Pat. No. 4,416,966 discloses that the color developer is self-contained, in which the color developer is present on the same support surface as the photosensitive microcapsules.
) discloses an image forming system. When the exposed imaging sheet is passed through a pressure roll, the microcapsules rupture and the internal phase is released imagewise. The color former then migrates to a developer, usually provided in a separate layer, where it reacts and forms a color image.

Both of the above two recording methods contain a photopolymerization initiator in a microcapsule, and the photopolymerization initiator has different photosensitive wavelength ranges, and the main body is converted to correspond to each photosensitive wavelength range. 1) The contents inside the microcapsules are cured using ultraviolet light. However, the common problem with these methods is that the means used to form the image is
In both cases, a latent image is formed on the recording medium by irradiating only ultraviolet light, that is, light energy, onto the substrate on which microcapsules are arranged. Either use a highly sensitive photosensitive material, or
Or, it was necessary to irradiate it with high-energy light.

However, high-sensitivity recording media that utilize only photoreactions have the fatal drawback of high sensitivity when irradiated with a light beam and poor storage stability near room temperature. In addition, to obtain high-energy light, the equipment must be large, and to obtain multicolor recording, the equipment must be large, and the cost of the equipment is also high1).
Not recommended for practical use. In addition, since the above method forms an image using only light energy, it can be used when outputting an image in response to an external signal, such as in a printer, or when reading an image from a color original, as in a color copying machine. This is inappropriate when applying image information to a recording medium after converting the image into a digital signal using a color image scanner. That is, when irradiating high-energy light, it is necessary to use short wavelength light, mainly ultraviolet light (1), and a digitally controllable light source for ultraviolet light is currently not available. For example, methods for obtaining a digital light source include liquid crystal shutter arrays and LE
Optical heads such as D-arrays have been devised, but even if these are miniaturized, liquid crystal molecules deteriorate at wavelengths in the ultraviolet region (1), and ultraviolet light cannot be extracted.

Furthermore, since the color development method uses leuco dye, it also has the disadvantage that the stability of the recorded image is poor due to the nature of the wood.

Furthermore, in order to facilitate development by applying pressure after exposure, it is necessary for the contents of the microcapsules to be a photosensitive composition that has a liquid phase at room temperature (1), resulting in poor storage stability;
Furthermore, the resulting image also has a practically undesirable characteristic, such as 1) the odor of the existing monomers due to the destruction of unreacted substances.

[Purpose of the invention]

The present invention was made in view of the above-mentioned conventional problems, and an object thereof is to provide a photopolymerization initiator that increases the photopolymerization rate of a photosensitive composition.

In particular, by appropriately selecting the sensitizer used in combination, argon
The object of the present invention is to provide a photopolymerization initiator that has sufficient sensitivity even in the ion laser oscillation range.

Further, the object of the present invention is to be able to form a high-quality transferred image, to be able to perform high-speed recording, to be able to perform halftone recording, and to be able to make complicated movements on a transferred medium even when obtaining a multicolored transferred image. It is an object of the present invention to provide a recording medium that can be effectively used in an image forming method capable of producing a clear, multicolor image without color shift.

A further object of the present invention is to provide a recording medium that does not require a special color developing layer and can form a clear transferred image on commonly used plain paper with low surface smoothness.

A further object of the present invention is to provide a highly sensitive recording medium that can record digital images with low power without requiring a special digital light source with high optical energy.

Furthermore, an object of the present invention is to provide a recording medium with high storage stability and high sensitivity.

A further object of the present invention is to provide a recording medium on which recorded images with excellent light resistance can be obtained.

A further object of the present invention is to provide a recording medium that can be used in an image forming method with very little cost since a clear multicolor recorded image with high gradation can be obtained using a small and inexpensive device.

[Means for solving problems]

The third object of the present invention is a photopolymerization initiator containing a compound represented by the following general formula (I) and a sensitizer, which represents an aromatic ring or a heterocyclic ring which may have, and which has a carbonyl group. has a substituent other than hydrogen at at least one β-position. Further, Ar' and Ar2 may be the same or different. ) and light, by simultaneously applying at least one type of energy in correspondence with the image recording information 1) to support a transfer recording layer whose physical properties governing its transfer characteristics change. A recording medium held on the body,
The transfer recording layer is formed from an image forming element that is solid at room temperature and includes at least a colorant and a sensitive component that is sensitive to the application of light energy and heat or heat convertible energy. The sensitive component represents at least a photopolymerization initiator and an aromatic ring or a heterocyclic ring which may have an unsaturated double bond, and β of a carbonyl group.
It has a substituent other than hydrogen at at least one position.

Further, Ar' and Ar' may be the same or different. ) and a sensitizer.

When the photopolymerization initiator of the present invention is mixed with a polymerizable compound containing an ethylenically unsaturated double bond, it significantly increases the photopolymerization rate.

Although it is not clear why the compound represented by general formula (r) becomes a highly sensitive photopolymerization initiator when used in combination with a sensitizer, the compound represented by general formula (I) Because it has a substituent other than a hydrogen atom, the mutual angle between the two carbonyl groups changes due to steric hindrance, causing distortion, which is affected by energy transfer or electron transfer from the sensitizer. This is thought to be due to the fact that the decomposition efficiency increases when In other words, it is thought that this is because a sensitizer with a large extinction coefficient efficiently absorbs light and interacts with the compound of general formula (I) to efficiently generate active species that initiate polymerization.

Here, the compound represented by general formula (I) will be explained.

In the formula, Ar' and Ar2 represent an aromatic ring or a heterocycle which may have a substituent, and have a substituent other than a hydrogen atom at at least one β-position of the carbonyl group. See you ^r
' and Ar2 may be the same or different.

Examples of the aromatic 8-ring include a benzene ring, a naphthalene ring, an anthracene ring, an indene ring, and a fluorene ring.

Examples of the heterocycle include a furan ring, a thiophene ring, a pyrrole ring, an oxazole ring, an isoxazole ring, a thiazole ring, an isothiazole ring, an imidazole ring, a pyrazole ring,
biran ring, pyridine ring, pyrrolidine ring, piperidine ring,
Indole ring, quinoline ring, isoquinoline ring, xanthine ring, carbazole ring, acridine ring, indoline ring,
Examples include julolidine ring.

Among the above, either or both of Ar' and Ar2 is preferably an aromatic ring, and more preferably a benzene ring.

Examples of substituents include hydrogen atoms, halogen atoms, alkyl groups, alkoxy groups, alkylamino groups, dialkylamino groups, alkylthio groups, and heterocyclic groups, specifically hydrogen atoms, methyl groups, ethyl groups, and isopropyl groups. ,tert
-butyl group, phenyl group, trifluoromethyl group, cyano group, acetyl group, ethoxycarbonyl group, carboxyl group, carboxilade group, amino group, methylamine group,
Dimethylamino group, ethylamino group, diethylamino group, isopropylamino group, diisopropylamino group, cyclohexylamino group, dicyclohexylamino group, acetylamino group, piperidino group, pyrrolidyl group, -P
O311 group, methoxy group, ethoxy group, propokine group,
Isopropoxy group, butoxy group, pentyloxy group, phenoxy group, hydroxyl group, acetoxy group, methylthio group, ethylthio group, isopropylthio group, mercap 1
group, acetylthio group, thiocyano group, methylsulfinyl group, methylsulfonyl group, dimethylsulfonyl group, sulfonato group, fluorine atom, chlorine atom, bromine atom, sulfur atom, iosyl group, trimethylsilyl group, triethylsilyl group, trimethylstannyl group group, furyl group, chenyl group, pyridyl group, piperidino group, morpholino group, pyrrolidyl group and the like. Among these substituents, hydrogen atom, methyl group, ethyl group, isopropyl group, methoxy group, ethoxy group, isopropoxy group, tert-butoxy group, phenoxy group, hydroxyl group, chlorine atom, bromine atom, cyano group, trifluoro Methyl and ru groups are preferred.

In general formula (1), the substituent other than the hydrogen atom substituted at at least one β-position of the carbonyl group is preferably an alkyl group, an alkoxy group, a hydroxyl group, a halogen atom, or the like. It is particularly preferable that the carbonyl group is substituted with 2 to 4 substituents at the β position with a substituent other than a hydrogen atom.

Next, specific examples of the compound represented by the general formula (I) will be given, but the present invention is not limited thereto.

In the present invention, examples of sensitizers used in combination with general formula (I) include coumarin derivatives, monoalkylamino groups, dialkylamino groups, cyclic alkylamino groups, styryl styryl ketone derivatives having alkoxy groups, monoalkylamino groups, dialkylamino groups, etc. Examples include aromatic compounds having a carbonyl group, such as styryl phenyl ketone derivatives having a group, a cyclic alkylamino group, and an alkoxy group, but the present invention is not limited thereto.

Some of these sensitizers are weak and have the ability to initiate photopolymerization, but these are not sufficient for practical use.

Next, a method for synthesizing the compound represented by general formula (I) will be explained. As an example, 2.2', 4.4', and 6.6' hexamethylbenzyl will be described.

First, mesityl (1) is formylated with POC+3 in DMF to obtain 2. Next, 2 was subjected to benzoin condensation with CN in Ej011-H20 to form 3! [(separated through column), oxidized to give 4.

Component weight ratio of photopolymerization initiator system, compound of general formula (I):
The sensitizer ranges from about 30=1 to about 1:30, preferably from about 10=1 to about 1:10.

Further, by adding an amine to the photopolymerization initiator of the present invention, the sensitivity can be further increased. These amines are used in an amount ranging from about 1:1 O to about 10:1 relative to the photopolymerization initiator.

In addition, as aromatic amines, ethyl-P-dimethylaminobenzoate, methyl-P-
Dimethylaminobenzoate, isoamyl-p-dimethylaminobenzoate, phenyl-p-dimethylaminobenzoate, ethyl-p-dimethylaminobenzoate, phenyl-p-diethylaminobenzoate, N,
N-dimethylaniline, N, N-diethylaniline, N
, N-dimethylbenzylamine, N-benzyl-N-methylaniline, N,N-dibenzylaniline, triphenylamine, etc., and aliphatic amines include trimethylamine, triethylamine, tripropylamine, dimethylcyclohexylamine, triethanolamine. Examples of the polyamine include methylene diamine, hexamethylene diamine, 1,4-cyclohexane diamine, and phenylene diamine, but the present invention is not limited thereto. Two or more of the above-mentioned amines may be used as a mixture.

The recording medium of the present invention will be explained below.

To perform transfer recording using the recording medium of the present invention, first, multiple types of energy including light are simultaneously applied to the transfer layer in correspondence with the image recording information, thereby improving the transfer characteristics. The physical properties that govern the transfer are changed, and the transferred image formed by the portion where the physical properties have changed is transferred to the transfer recording medium by using, for example, heating and pressure. The physical properties that govern this transfer characteristic are arbitrarily determined depending on the type of recording medium used1). In the case of a transfer recording medium in which the transferred image is transferred in an adhesive state or in a permeable state to the transfer medium,
Viscosity at the same temperature. In addition, the multiple types of energy used to form the transferred image are arbitrarily determined depending on the type of recording medium used, such as photoelectron beam, heat,
Pressure, etc. are used in appropriate combinations.

A preferred image forming method for forming an image on the recording medium of the present invention will be described. In order to understand this, an example using a recording medium on which a transferred image is formed by light and thermal energy will be explained with reference to FIGS. 1a to 1d.

The time axes (horizontal axes) of the graphs in FIGS. 1a to 1d correspond to each other. Further, the transfer recording layer contains at least a photopolymerization initiator and a monomer, oligomer, or polymer having an unsaturated double bond, which will be described later, as a sensitive component. FIG. 1a shows the rise in the surface temperature of the heating means and the subsequent temperature drop when the heating means such as a thermal head is driven to develop heat from time 0 to t3. The transfer recording medium that is in pressure contact with the heating means exhibits a temperature change as shown in FIG. 1b as the temperature of the heating means changes. That is, t.

The temperature rises with a time delay of , and similarly reaches the maximum temperature at time t, which is delayed from t3, and thereafter the temperature decreases.

Next, the present invention will be explained in detail using the softening temperature.

Let Ts be the softening temperature of the transfer recording layer. The viscosity of the transfer recording layer decreases to a negative value in the temperature range below Ts. This state f is shown by curve A in FIG. 1C. After reaching Ts at time t2, the viscosity continues to decrease until time t4 when the maximum temperature is reached, and as the temperature decreases, the viscosity increases again and shows a rapid increase until time t6 when it drops to Ts. In this case, the transfer recording layer is heated
Basically, the physical properties do not change, and when heated to a temperature higher than Ts in the next transfer step, the viscosity decreases in the same way as mentioned above.

Therefore, if the transfer recording layer is brought into pressure contact with the transfer medium and heated to a temperature necessary for transfer, for example, heating to 18 or higher, the transfer recording layer will be transferred for the same reason as the transfer mechanism of conventional thermal transfer recording, but the transfer recording layer of the present invention In this case, as shown in Fig. 1d, if the transfer recording layer is heated and light irradiated at the same time as time t2, the transfer recording layer will soften and the reaction initiator contained in the transfer recording layer will be activated, and the temperature will slow down the reaction rate. If the height is increased sufficiently, the probability that the polymerizable monomer will polymerize increases dramatically, so that curing progresses rapidly.

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. 1c. As the reaction progresses, the softening temperature rises and changes from Ts to Ts' at time t5 when crosslinking ends. This situation is shown in 1d
Shown in the figure. Therefore, when heated in the next transfer process, Ts'
There is a difference in properties between the part that has changed and the part that has not changed.

Along with this, the transfer start temperature Ta, which is the temperature at which the transfer recording layer starts transferring, also changes and becomes Ta'. Therefore, by heating to Tr that satisfies, for example, Ta<Tr<Ta', only the portion where the softening temperature does not rise will be transferred to the transfer medium. Ts' at this time depends on the temperature stability accuracy of the transfer process.
-Ts is preferably about 20°C or higher. In particular, the temperature is preferably 10°C or higher. This value is also the same when TS>Ts'. In this way, a transfer image can be formed by controlling heating or non-heating according to the image signal and simultaneously irradiating light.

In addition to the softening temperature explained above, the physical properties that govern the transfer characteristics of the transfer recording layer include the melting temperature and the glass transition point, but in any case, the melting temperature, glass transition point, etc. A transferred image is formed in the transfer recording layer by utilizing irreversible changes such as the glass transition point. Further, the softening temperature, melting temperature, and glass transition point vary in almost the same manner, so the above explanation using the softening temperature is also an explanation using the melting temperature and the glass transition point.

Incidentally, the transfer start temperature in the present invention is measured as follows.

A 6 μ thick transfer recording layer coated on a polyethylene terephthalate (PET) film and a surface smoothness (Beck smoothness) used as a transfer medium of 50 to 200 seconds and a thickness of 0.
．． 2.5mm/s by placing 2mm+ high-quality paper facing each other and sandwiching the transfer recording medium and the high-quality paper between the two rolls shown below.
It is transported at a speed of ec. The first roll of the two rolls is placed on the transfer recording medium side, is an iron roll with a built-in 300W halogen heater, and has a diameter of 40 mm. In addition, the second roll on the high-quality paper side is an iron roll with a diameter of 40 mm, and the surface is coated with fluororubber with a thickness of 0.5 a + m1).
, the two rolls are facing each other with a linear pressure of 4 K g/cm. The surface of the first roll is detected by a thermistor, and the halogen heater is controlled to maintain it at a predetermined temperature.

4 seconds after passing between the two rolls, while keeping the high-quality paper flat, pull the transfer recording medium and the high-quality paper at an angle of approximately 90° at a speed equal to the conveyance speed of the rolls to separate the transfer recording medium and the high-quality paper. Then, observe whether or not the transfer recording layer has been transferred to the high-quality paper.

In this way, the surface temperature of the beet roll (first roll) is gradually increased (heating rate 10°C/M I N or more).
F) Measure the temperature when the optical density of the transferred image is saturated and find out the transfer start temperature.

Here, physical property changes governing transfer include changes in the glass transition temperature Tg or softening temperature Ts of the recording medium;
or fd Humidity melting temperature Tm?1 Since the recording medium of the present invention obtains a recorded image in the subsequent transfer process, it is only necessary to change the adhesion state or permeability state to the recording medium, and a clear The above Tg.

Adaptation is possible even without a change in Ts or Tm.

In addition, the multiple types of energy used only to form a transferred image include light and heat, or electricity that can be converted into heat;
A combination of energy selected from ultrasonic waves and pressure is preferable in terms of energy efficiency.

The photopolymerization initiator which is a component of the recording medium of the present invention is the same as the photopolymerization initiator described above.

When the sensitive component of the recording medium is solid as in the present invention, the reaction rate largely depends on the diffusion rate of the photopolymerization initiator. Furthermore, when the photopolymerization initiator has a synergistic effect in a composite system, the influence of the diffusion rate of the photopolymerization initiator is greater than in a single component system. In the present invention, recording is performed by applying light energy and heat or energy that can be converted into heat to the sensitive component of the recording medium, but since the sensitive component of the recording medium is solid at room temperature, heat or thermal energy that can be converted to heat is recorded. The diffusion rate of the photopolymerization initiator contained in the sensitive component changes greatly depending on the addition of the compound. Here, as mentioned above, <photopolymerization initiator or 2
In the case of a component system, compared to a single-component photopolymerization initiator, the reaction rate depends more on the diffusion rate of the photopolymerization initiator, so the reaction rate can be significantly changed by applying heat or energy that can be converted into heat. be able to. In other words, if the photopolymerization initiator is a two-component photopolymerization initiator consisting of a combination of the compound of general formula (1) and a sensitizer (1), and the synergistic effect is large, only light energy is imparted to the sensitive component. As mentioned above, when light energy and heat or energy that can be converted into heat is applied, the thermal dependence of the diffusion rate of the photopolymerization initiator is higher than that of a one-component system. Since the agent is larger, the contrast of the recording can be increased.

The amount of the photopolymerization initiator (compound of general formula (I) in the sensitizer) contained in the sensitive component of the recording medium of the present invention is the weight ratio of the photopolymerization initiator to the compound having an unsaturated double bond. Preferably, the range is from about 1=5 to about 1:1000, and more preferably from about 1=lθ to about 1:1OO.
That's it.

In addition, the monomers, oligomers, and polymers having unsaturated double bonds used in the recording medium of the present invention include polyisocyanates, alcohols containing unsaturated double bonds (which may be reacted with polyols if necessary) , urethane acrylates and urethane methacrylates having urethane bonds synthesized by polyaddition reaction of amines, and epoxy acrylates synthesized by addition reaction of epoxy resin and acrylic acid or methacrylic acid, polyester acrylates, and spin acrylates. The present invention is not limited thereto.

In addition, polymers have a main chain with polyalkyl, polyether, polyester, polyurethane, etc.
Examples include those having four polymerizable and crosslinkable reactive groups such as acrylic group, methacrylic group, cinnamoyl group, cinnamylidene acetyl group, furyl acryloyl group, nisder cinnamate, etc. in the side chain, but the present invention is not limited to this.

In addition, it is desirable that the polymers, oligomers, and polymers mentioned above are completely solid or in a solid state at room temperature.
Even if it is liquid, it does not matter if it maintains a semi-solid or solid state when mixed with the binder described below. Also,
The above-described polymer, oligomer or polymer having an unsaturated double bond and a photopolymerization initiator may be used in combination with a binder.

Any organic polymer may be used as the binder as long as it is compatible with the monomer, oligomer, or polymer having unsaturated double bonds.

As the binder, a conventionally known organic polymer is used. For example, there are addition polymers with carboxyl groups in their side chains, such as methacrylic acid copolymers, acrylic acid copolymers, itaconic acid copolymers, partially esterified maleic acid copolymers, maleic acid copolymers, etc. . Also, chlorinated polyethylene.

Chlorinated polyolefins such as chlorinated polypropylene, polymethyl methacrylate, polyacrylic acid, polymethacrylic acid, polyacrylic acid, alkyl esters, acrylic acid alkyl esters and acrylonitrile, vinyl chloride,
Copolymers of vinylidene chloride, styrene, butadiene, etc.
Polyvinyl chloride, vinyl chloride and acrylonitrile!
n compound, polyvinylidene chloride, copolymer of vinylidene chloride and acrylonitrile, polyvinyl acetate, copolymer of vinyl acetate and vinyl chloride, polyvinyl alcohol, polyvinylpyrrolidone, polyacrylonitrile, copolymer of acrylonitrile and styrene, Copolymers of acrylonitrile and butadiene and styrene, polyvinyl alkyl ether, polymethyl vinyl ketone, polyethyl vinyl ketone, polyethylene, polypropylene, polystyrene,
Examples include polyamide, polybutadiene, polyisoprene, polyurethane, polyethylene terephthalate, chlorinated rubber, polychloroprene, and polystyrene-butadiene 1IN bases. Among the polymers listed in L, those preferably used include polyethylene chloride, polymethyl methacrylate, polyvinyl chloride, vinylidene chloride-acrylonitrile copolymer, polystyrene, styrene-acrylic copolymer, polyvinyl butyral, polyvinyl acetate, and vinyl chloride-acetic acid. Examples include vinyl copolymers and chlorinated rubber. These may be used alone or in a mixture of two or more. The binder is 1wL% to 90wL% of the sensitive component,
Preferably, the content is 1 wL% to 80 wL%.

Waxes, whether compatible or incompatible, are also used, including vegetable waxes such as candelilla wax, carnauba wax, and rice wax, animal waxes such as beeswax and spermaceti, and mineral waxes such as ceresin and montan wax. There are petroleum waxes such as polyethylene wax, paraffin wax, polyethylene wax, Sasol wax, montan wax derivatives, paraffin wax derivatives, hydrogenated castor oil, hydrogenated castor oil derivatives, and synthetic waxes made of fatty acids and fatty acid amide esters such as stearic acid. In the present invention, one type or a mixture of two or more types of these waxes may be used.

, n coloring agent is a component contained in order to form a chemically recognizable image (1), and various pigments and dyes are used as appropriate. Examples of such pigments and dyes include inorganic pigments such as carbon black, yellow lead, molybdenum red, and red iron.
Banza Yellow, Benjishi Yellow, Brilliant Carmine 6B, Lake Red C, Permanent Red F5R
, phthalocyanine blue, Victoria Blue Lake, Fast Sky Blue, etc., and coloring agents such as leuco dyes and phthalocyanine dyes.

The amount of coloring agent is 0.000000000000000 with respect to the sensitive component and the binder.
1 to: ]0ffi 'Q section is preferred. Furthermore, additives such as thermal polymerization inhibitors and plasticizers may be added to the sensitive component of the present invention, if necessary.

Even if the above-mentioned sensitive component is dissolved in a solvent and coated on a support in a continuous layer, the sensitive component is dissolved in a particulate image forming element, or the particulate image forming body is formed into a microcapsule. It may also be applied to a support. The support used in the present invention is selected from film-like materials such as polyethylene terephthalate and polyamide.

The support may be provided with other coating layers, an antihalation 1L layer, an ultraviolet absorbing layer, and a visible light absorbing layer on its surface, if necessary, to facilitate bonding.

29 In order to prevent the sensitivity from decreasing due to oxygen, the composition of the present invention is provided with a removable transparent cover, or with a photosensitive layer as described in Japanese Patent Publication No. 40-17828. A coating layer with low oxygen permeability can be provided thereon.

The recording medium according to the present invention has two layers on the base film (1).
Although it is possible to use 1 ton of L sheets, in order to prevent low sensitivity due to oxygen inhibition in the atmosphere, a film of polyethylene, polypropylene, etc. is pressed onto the recording medium, and the hairs that peel off after the latent image of transfer recording is formed. Dans are also effective. Also, −
If the left image forming element is granulated and coated with a high molecular compound having low oxygen permeability, low sensitivity can be prevented and image resolution can also be improved. Furthermore, a plurality of types of compositions using coloring materials and sensitizers with different photosensitive wavelength regions or conventionally known photopolymerization initiators are microencapsulated and randomly supported on a base film, and each photopolymerization By simultaneously applying a plurality of types of energy including light of a wavelength corresponding to the photosensitive wavelength range of the initiator and at least one type of energy corresponding to image recording information, a recording medium compatible with color recording can be obtained.

When microcapsules are used in the image forming element constituting the transfer recording layer, the material described in Section F is contained in the core portion. Examples of materials used for the wall material of microcapsules include gelatin, gelatin-gum arabic, sodium alginate, polyvinyl alcohol, ethyl cellulose, nitrocellulose, cellulose-based urea-formalin such as nitrocellulose, resorcinol-formaldehyde, urea-formaldehyde, isocyanate, Isocyanate-polyol, melamine-formaldehyde,
Hydroxypropyl cellulose, polyvinyl chloride, polyvinyl chloride-cellulose, acetate butyrate, polyvinyl acetate, polystyrene, polyethylene, polymethyl methacrylate, polyamide, styrene-acrylonitrile copolymer, vinylisodene chloride-acrylonitrile copolymer
Coalescence, epoxy resin, polyvinyl formal, vinyl chloride-vinyl acetate copolymer, polyester, polyacrylic acid ester, cellulose acetate butyrate, polyvinyl pyrodone, polyvinyritine chloride, nylon, tetron, uriurethane, polycarbonate, maleic anhydride type Copolymers, polyethylene terephthalate, etc. are used.

In the transfer recording medium of the present invention, the thickness of the transfer recording layer is 1 to 20
μ is preferable, and 3 to 10 μ is especially preferable. When the transfer recording layer is constituted by image forming elements of microcapsules, the particle size of the macrocapsules is preferably 1 to 20 .mu.m, particularly preferably 3 to 10 .mu.m. Further, the particle size distribution of the microcapsules is preferably ±50% or less, particularly preferably ±20% or less with respect to the numerical average diameter. The thickness of the wall material of the microcapsule is preferably 0.1 to 2.0μ,
Particularly preferred is 0.1 to 0.5μ.

Any conventionally known method can be applied as the microencapsulation method, such as the simple corecellation method,
Complex core cellification method, interface combination method, 1
The n-siLu stone method, interfacial precipitation method, phase separation method, spray drying method, air suspension coating method, mechanochemical method, etc. are used.

The microcapsule image forming element is bound to the substrate using a coating binder such as polyvinyl alcohol (PVA) or epoxy adhesive. The thickness of the coating binder is preferably 0.1 to 1 μm.

In the recording medium of the present invention, radical reactions in the transfer recording layer may be suppressed due to oxygen in the air. In order to prevent this, for example, a transfer recording layer using a polyvinyl alcohol aqueous solution with a small amount of surfactant added as an oxygen prevention layer.
It is preferable to apply it to F. This oxygen prevention layer is removed by washing with water after the transfer image is formed. In addition, in the case of a microencapsulated element, it is possible to provide the wall material with a function as an oxygen prevention layer.

The recording medium of the present invention can be manufactured, for example, as follows.

The recording medium of the present invention is prepared by melt-mixing components such as a sensitive component, a stabilizer, a coloring agent, and applying the mixture onto a substrate using an applicator or the like. In addition, when the transfer recording layer is composed of an image forming element, the on-print components are made into minute image forming elements for each color by spray drying, etc., and then together with a binder such as polyester resin, each color image is formed. After sufficiently mixing the element body in a solvent such as methyl ethyl ketone or ethylene glycol diacetate, it is coated with a solvent such as polyimide, and further dried at 80°C for 3 minutes to remove the solvent. Obtain a recording medium of °
I (come on.

When the image-forming element is composed of microcapsules, the image-forming element of microcapsules is manufactured, for example, by a method detailed in the Examples below,
The substrate-F is coated by a solvent coating method in the same manner as in the case of the image forming element on particles.

Further, the granular element may be electrostatically attached to a support, and in this case, the granular element or the support or both are corona-charged or tribo-electrified and attached.

In the present invention, the method of physically or chemically supporting the image forming element on the support includes the above-mentioned solvent coating method or electrostatic adhesion method 1), and the chemical method. For example, there is a method in which functional J1 is provided on each of the contacting surfaces of the image forming element and the support and chemically bonded to each other.

Examples of the support include polyester, polycarbonate, triacetylcellulose, nylon, polyimide, polyethylene terephthalate, and metals such as aluminum, and these may be in the form of a film, plate, drum, or sphere.

〔Example〕

Next, examples using the photopolymerization initiator of the present invention will be described.

As a light source, a fluorescent lamp having the following characteristics in accordance with the absorption characteristics of the sensitizer was used.

Light source A Emission peak: 335 nm (Toshiba ■ FLIOA 70E:15) // B
// 390nm (FLIO^70E manufactured by Toshiba ■
39) //C//450nm (FLIOA70B manufactured by Toshiba ■) The photosensitive material in the Examples was prepared in the following manner.

Preparation of photosensitive material) 15 g of special acrylate 400 manufactured by Toagosei Kagaku Kogyo Co., Ltd. as an ethylenic compound, 10 g of chlorinated rubber as a binder, and a photopolymerization initiator were dissolved in 100 ml of dichloromethane. The solution was applied onto an aluminum plate using a spinner and dried at 60°C for 5 minutes to form a photosensitive layer. (Thickness: about 10 .mu.m) Next, a sample was prepared by coating PVA (polyvinyl alcohol) as an oxygen prevention layer on the navigation photosensitive layer to a thickness of 5 .mu.m.

Examples 1 to 14 An optical wedge (optical density 0 to 15 steps) was placed on the sample, and after exposure for -1 minute, the PVA was washed with water, and the photosensitive layer was further treated with 1.1.1- trichloroethane for 30 seconds and developed. did. The highest number of optical wedges corresponding to the image that appears is expressed as the sensitivity of the sample. (Table 1) (The higher the value expressed from 0 to 15, the higher the sensitivity.) The photopolymerization initiator is a compound of general formula (I): sensitizer to 1 part (weight ratio) in the photosensitive layer. The amount of amine added was adjusted to 2 wt%, and when adding the amine, the amount added was adjusted to be the same as that of the photopolymerization initiator.

Comparative Examples 1 to 14 In addition, as a comparative example, the sensitivity when using only a sensitizer was
Shown in the rightmost column of the table.

Examples 15 to 19 Next, examples using an argon ion laser as a light source will be shown.

Using an argon ion laser (manufactured by Rheonics) with an output of IW or 4W, irradiate with a beam diameter of 100 scales using the apparatus shown in Figure 8 and expose! It was adjusted by changing the rotational speed of the rotary plate to which the sample was fixed.

Using a sensitizer that has absorption near 488r+m, which is the oscillation wavelength of the argon ion laser, and a compound of general formula (I), prepare the sample in the same manner as in the example above, and apply it to the rotating plate (aluminum) -F. Recording sensitivity was measured. The results are shown in Table 2.

・Numbers in the table (mj/cm2) ・100 mJ/cr when the compound of general formula (I) is not added
No reaction even after irradiation up to n''.

As is clear from Tables 1 and 2, the sensitizer and the general formula (I
) can be used in combination with extremely high sensitivity (1), and when a sensitizer with absorption near 48 nm is used, high sensitivity can also be obtained for argon ion lasers.

The present invention will be explained below using examples.

Examples 20 to 41) The components shown in Table 3 were dissolved in dichloromethane solvent,
It was coated on a polyethylene terephthalate film with a thickness of 6 mm to a thickness of 4 mm. Apply polyvinyl alcohol (M w = 1200) aqueous solution to the water film to prevent oxygen.
(film thickness: 0-) was formed and used as a sample.

Next, the sample prepared by the F-grip method was wound into a roll and incorporated into the apparatus shown in FIG.

The thermal head 4 is a line type of 8-4 size with 8 tonts/mm and heat generating element rows are arranged in the groove and the ridge part, and the base material side of the recording medium 1 is in contact with the heat generating elements. The heating element was pressed against the heating element by the tension of the recording medium 1.

Then, chemical lamps 3 were placed at opposing locations.

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

This embodiment deals with a transfer recording layer in which light and heat are applied, causing the Carlos dislocation point to rise by L and the transfer start temperature to rise, resulting in negative recording. In other words, the thermal head control is such that no current is applied when the mark signal (black) is present, and when there is no mark signal (
When it is white), it is energized to generate heat. The energizing energy during this heat generation is 0.8W/dot xχm5ec, and the chemical lamp is synchronized with the signal of the thermal head to be χm5e.
To make the light irradiation uniform, control and drive the thermal head according to the image signal as described in 2xm5ec/1.
ine was repeated and the recording medium was synchronously conveyed by a stepping motor and a drive rubber roll.

Next, the polyvinyl alcohol film was removed, and the surface smoothness was in the range of 10 to 30 seconds as shown in Figure TS3.
was superimposed on the transfer recording layer and conveyed while being sandwiched between a beat roll 8 and a pinch roll 9. The heat roll 8 had a 300 W heater inside, and the heater was controlled to maintain the surface at an arbitrary temperature in the range of 50 to 150° C. using an aluminum roll whose surface was coated with 2) thick silicone rubber. Pinch roll 9 is J
It was pressed with a silicone rubber roll having a hardness of 50 @ on an IS rubber hardness meter to a pressure of 1 to 1.5 kg/cm.

Heat roll, after conveying the paper passed over the transfer recording layer in the range of 110°C to 130°C, peeling off the base film (support 1b), minimum time χm5e to obtain an image.
c was determined and used as the sensitivity. (However, χ is 2m5ec, 5m
5ec, 10m5ec, thereafter increased every 51IISeC) In other words, the smaller the value of χ, the higher the sensitivity.

Moreover, the obtained image was a high-quality image with good fixability.

Next, Table 4 shows the sensitivity χ171SeC of the combination of the sensitizer and the compound of general formula (I).

The chemical lamp shown in FIG. 2 and 3 was selected from the following A, B, and C according to the absorption wavelength of sensitizer 1.

Lamp A Toshiba Kikki [108701mi35/:]:]T1
5 emission 1515 emission peak lamp B Toshiba ■F [, IOA 70E39/:13T
15 Emission peak 190 nm Lamp C Toshiba@Fl, 10^70B/:13T15 Emission peak 450 nm No image was formed in the range up to χ = 200 [ms].

As is clear from Table 4, the compound of general formula (I) interacts with various sensitizers and becomes a highly sensitive recording medium.

Present amine: The amine used was ethyl-P-dimethylaminobenzoate.Next, an example in which a multicolor image was drawn using the recording medium of the present invention will be shown.

Example 42) As shown in FIG. 4, the transfer recording layer 1b has a core lc.

A microcapsule-shaped image forming element was formed by using the material having the composition shown in Tables 5 and 6 as 1d by the method shown below.

Table 5 Table 6 In other words, 10 g of the ingredients shown in Tables 5 and 6 were first mixed with 20 parts by weight of methylene chloride, and then a surfactant such as a cationic or nonionic surfactant having an HLB value of at least 10 or more and 1 g of seratin were added. Mix in 20f) nl of dissolved water and heat at 60°C.
a, oo using a homomixer under heating.

Stir at ~10,00 rpm to emulsify, average particle size 26
Obtain μ eggplant oil droplets.

Stirring was continued at 60° C. for 30 minutes, and the methylene chloride was distilled off to give an average particle size of 10 μA. Add 20 ml of water in which 1 g of gum arabic was dissolved, cool slowly, and then add NH4 ammonia water to reach pHll.
A microcapsule slurry is obtained by the above steps, and 1 j) ml of a 20% glutaraldehyde aqueous solution is slowly added to harden the capsule walls.

After that, solid-liquid separation was carried out using a Nutsche filter, and 35
C. for 10 hours to obtain a microcapsule-shaped image forming element.

This image forming element has cores lc and l in Tables 5 and 6.
Microcapsules d covered with shell 1e are formed to have a particle size of 7 to 15 μm and an average particle size of 10 Iin.

The image forming element formed as described above was coated with 5% PVA.
A transfer recording layer 1b is formed by adhering to a support made of a polyethylene terephthalate film of J7 size and 6 μm using an adhesive 1f made of an aqueous solution containing several X+ surfactants per 10Occ, thereby forming a recording medium 1. .

The sensitizer in the image forming element shown in Table 5 absorbs light in the band of graph D in the light absorption characteristics shown in FIG. The sensitizer in the forming element absorbs light in the band of graph E in the light absorption characteristics shown in FIG. 5, and becomes blue during image formation.

Next, the transfer recording layer 1b was wound into a roll and incorporated into the apparatus shown in FIG. However, the light source indicated by 3 here has an emission peak of 450n, corresponding to the sensitizer exhibiting the above absorption characteristics.
m lamp C (Toshiba @ FLIOA70B) and lamp F with an emission peak of 352 nm (Toshiba FLIO,A 70E)
Place two BL). The transfer recording layer 1b has the property that when light and heat of a predetermined wavelength are applied, the softening point temperature rises and the transfer recording layer 1b is no longer transferred to the recording paper. During color recording, power is not applied to the heating element corresponding to the magenta color of the image signal in the heating element row of the thermal head, and a current of 20m5ec is applied to the portion corresponding to the white color of the image signal (the recording medium is white), and at the same time the lamp is turned on. C is uniformly irradiated with an irradiation time of 25 m5 ec.

Next, when recording R color, after 25 m5 ec has passed after the end of the irradiation, that is, 50 m5 ec after the energization time, the heating element corresponding to the blue color of the image signal among the heating element rows of the thermal head is not energized and the image is recorded. A portion of the signal corresponding to white is energized for 35 m5 ec, and at the same time, lamp F is uniformly irradiated for an irradiation time of 45 m5 ec.

In the manner described above, a negative image is formed on the transfer recording layer 1b by controlling the thermal head according to the blue, magenta, and white image signals, and the recording medium 1 is synchronously transferred with an edge-turning cycle of 100 m5ec/line. transport.

Next, in the same manner as in Example 1), a sheet of paper is stacked on the transfer recording layer, pressed and heated, so that a two-color transfer image of blue and magenta can be transferred onto plain paper.

As described above, two-color recording is performed in one shot.

Example 43) In Table 5 of Example 42), 3W of Irgacure 184 (Ciba Geigy), a photopolymerization initiator, was used instead of using 2w% of the compound of general formula (I) without using a sensitizer.
96, the content of ethyl-P-dimethylaminobenzoate was increased from 1wt to 2w96, and microcapsules were formed in the same manner as in Example 42). 313n
m Toshiba FLIOA70'E31), sensitizer 3.3'
-Carbonylbis(7-ethylamino) A two-color transfer image of blue and magenta was transferred onto plain paper in exactly the same manner as with 7-ethylamino.

〔Effect of the invention〕

As explained above, the photopolymerization initiator of the present invention has extremely high sensitivity (1) and is also highly sensitive in the oscillation range of an argon ion laser.

Since recording is done as a process, it is possible to form high-quality images.
Halftone recording is possible, and multicolor recorded images can be formed easily and inexpensively.Furthermore, when the transfer recording layer is composed of granular image forming elements, each solid image forming element can be used as a recording material. Transfer recording is achieved by adhering to the surface of the paper, so clear, fog-free recorded images can be obtained even on commonly used plain paper with low surface smoothness, making it easy to record digital images. Furthermore, the recording medium of the present invention has the following effects: it is possible to satisfy both optical and thermal recording and storage stability at the same time.

[Brief explanation of the drawing]

Figures 1a to 1d are diagrams of the principle of transfer recording using the recording medium of the present invention, and Figures 1), 2, and 3 are schematic diagrams of an apparatus for performing transfer recording using the recording medium of the present invention. 1), Figure 4 is a configuration diagram of a transfer recording medium 1), Figure 5 is an explanatory diagram showing the light absorption characteristics of the sensitizer in the transfer medium 1), Figures 6 and 7. 1) is a timing chart for applying heat and light, and FIG. 8 is a schematic diagram of an apparatus for exposure with an arbo-ion laser. DESCRIPTION OF SYMBOLS 1...Recording medium, 1a...Support, 1b...Transfer recording layer, lc, 1d-=ffa, 1e- is shell (wall material), 1f...Adhesive, 2...・Supply roll, 3...
・Lamp, 4... Thermal head, 5... Control circuit, 7... Heater, 8... Beat roller, 9...
- Pinch roller - 510... Plain paper, 11... Winding roll, 12... Recorded image, 13... Argon ion laser - 114... Shutter, 15... Lens, 16... Rotating plate, +7-...motor. Figure 2 Figure 3 Figure 5 Sakucho nm Figure 6

Claims (7)

[Claims] (1) A photopolymerization initiator containing a compound represented by the following general formula (I) and a sensitizer. ▲There are mathematical formulas, chemical formulas, tables, etc.▼General formula (I) (In the general formula (I), Ar^1 and Ar^2 represent an aromatic ring or a heterocycle that may have a substituent, and a carbonyl group has a substituent other than hydrogen at at least one of the β-positions.Also, Ar^1 and Ar^2 may be the same or different.) (2) Claim 1 contains amines in addition to the compound represented by the general formula (I) and the sensitizer.
The photopolymerization initiator described in . (3) By simultaneously applying multiple types of energy, including light, at least one type of energy corresponding to image recording information, a transfer recording layer whose physical properties governing its transfer characteristics change can be formed on a support. an image-forming element that is solid at room temperature, the transfer recording layer comprising at least a colorant and a sensitive component that is sensitive to the application of light energy and heat or heat-convertible energy; The sensitive component contains at least a photopolymerization initiator and a monomer, oligomer, polymer, or a mixture thereof having an unsaturated double bond, and the photopolymerization initiator has the following general formula (I) ▲Math. , chemical formulas, tables, etc. ▼ General formula (I) (In general formula (I), Ar^1 and Ar^2 represent an aromatic ring or a heterocycle that may have a substituent, and β of the carbonyl group It has a substituent other than hydrogen in at least one of the positions. Also, Ar^1 and Ar^2 may be the same or different.) and a sensitizer. A recording medium characterized by being a physical object. (4) The recording medium according to claim 3, wherein the photopolymerization initiator contains an amine in addition to the compound represented by the general formula (I) and a sensitizer. (5) The recording medium according to claim 3 or 4, wherein the image forming element contains a binder. (6) Any one of claims 3 to 5, wherein the image forming element is in the form of particles and is physically or chemically supported on the support to form a layer. Recording medium written in crab. (7) The recording medium according to claim 6, wherein the image forming element is covered and encapsulated with a wall material.