JP2006062346A - Method for curing curable liquid composition, method for inkjet recording and apparatus for inkjet recording - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method capable of efficiently curing an electromagnetic radiation-curable liquid composition comprising a solvent polymerizable in the presence of an acid, and a photo acid-generating agent dissolved in the solvent and generating the acid by irradiating with an electromagnetic radiation. <P>SOLUTION: The method for curing the electromagnetic radiation-curable liquid composition comprising the solvent polymerizable in the presence of the acid, and the photo-acid generating agent dissolved in the solvent and generating the acid by irradiating with the electromagnetic radiation, is provided. This method is characterized by that a process wherein the electromagnetic radiation-curable liquid composition is fed on a recording medium to form a composition layer, and a process wherein the acid is generated from the photo acid-generating agent by irradiating the composition layer with the electromagnetic radiation containing a wavelength to be absorbed in the photo acid-generating agent to cure the composition layer, are provided, and the recording medium is heated so that the temperature of the recording medium becomes higher than the temperature of the electromagnetic radiation-curable composition fed. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a method of curing an electromagnetic radiation curable liquid composition that is cured by an acid generated by electromagnetic radiation irradiation, and an ink jet recording apparatus.

  In recent years, on-demand printing presses that can respond quickly to diversifying needs and can reduce inventory are being used. As an on-demand printer, an electrophotographic printer using toner or liquid toner and an inkjet printer capable of high-quality printing at high speed are expected. In an ink jet printer, solvent-based ink can be handled in a closed system until it is discharged onto the printing surface. The ink used needs to have the fluidity necessary for ejection, and the solvent concentration in the ink must be sufficiently high. For this reason, it is essentially difficult to solve the problem of atmospheric pollution caused by organic solvents. Also, with solvent-based inks, the printing surface may deteriorate as the ink layer is dried, and it is not always easy to obtain a high-quality printed matter.

  In order to solve the problem caused by the organic solvent, an ink that is cured by UV irradiation (UV ink) and a printer system using the ink have been proposed. Typical examples of the UV ink include those containing a radical polymerizable monomer, a photopolymerization initiator, and a pigment (see, for example, Patent Document 1 and Patent Document 2). Light cure. Although the ink layer is immediately de-fluidized, a relatively high quality printed matter can be obtained. However, when a printing surface is an absorbing medium, a general UV ink is hard to be cured inside the absorbing paper surface. .

  Recently, an ink jet recording head that discharges ink onto a recording medium to form an ink layer, a conveying means that conveys the recording medium, a light source that irradiates light to the ink layer, and a heating means that heats the ink layer. An ink jet recording apparatus including the above has been proposed (see, for example, Patent Document 3). In the recording process by this recording apparatus, a photo-curable inkjet ink containing a photoacid generator that generates an acid by irradiation with electromagnetic radiation, a color component, and a solvent that polymerizes in the presence of the acid is used. The ink layer formed on the surface is irradiated with electromagnetic radiation. As a result, an acid is generated from the photoacid generator in the ink, and this acid diffuses inside the ink layer by heating the ink layer. The acid acts as a catalyst to polymerize and cure the ink, and the ink that has penetrated into the absorbent paper surface can also be cured. However, such an ink jet recording apparatus must be provided with a large heating means separately from an ink jet recording apparatus using a general UV ink (acrylic photocurable ink jet ink).

  Acrylic photocurable ink-jet ink has a higher viscosity at normal temperatures than ordinary ink-jet inks. Therefore, a heating means is provided in the supply path for supplying UV ink into the recording head in order to reduce the viscosity and stably discharge the ink. Provided. Furthermore, a recording medium temperature detecting means is provided to detect the temperature of the recording medium, and a recording medium temperature adjusting means for adjusting the temperature to a target set temperature is provided to adjust the spread of dots on the recording medium formed by ink droplets. An ink jet recording apparatus that holds high-quality printing is known (for example, see Patent Document 4).

In addition, in order to print on various recording media, a recording medium selection unit, an inkjet nozzle temperature control unit, and a recording medium temperature control unit are provided, and the conditions suitable for the recording medium, that is, the ink temperature and the recording medium temperature are adjusted. An ink jet recording apparatus that performs high-quality printing is also known (see, for example, Patent Document 5).
JP-A-8-62841 JP 2001-272529 A Japanese Patent Laid-Open No. 2004-2668 JP 2003-145728 A JP 2003-165207 A

  As described above, since the conventional ink jet recording apparatus requires a large heating means for heating the recording medium, the liquid composition, and the UV ink, it is inevitable to increase the size of the apparatus. Furthermore, the heat radiated from the light irradiation means together with the electromagnetic radiation such as ultraviolet rays or the heat of the heating means is not always effectively used and may be taken away by the recording medium or its conveying means. As a result, heat necessary for curing the UV ink is not sufficiently applied to the ink layer, resulting in insufficient heating. In this case, the diffusion of the acid, which can be said to be the lifeline of the chemical amplification mechanism, is not sufficiently performed, resulting in poor curing.

  The present invention efficiently provides an electromagnetic radiation curable liquid composition comprising a solvent that polymerizes in the presence of an acid and a photoacid generator that is dissolved in the solvent and generates an acid upon irradiation with electromagnetic radiation. An object is to provide a method of curing.

  The present invention also provides an ink jet discharge of an electromagnetic radiation curable liquid composition containing a solvent that polymerizes in the presence of an acid and a photoacid generator that is dissolved in the solvent and generates an acid upon irradiation with electromagnetic radiation. An object of the present invention is to provide an efficient recording method and an apparatus therefor.

A method for curing an electromagnetic radiation curable liquid composition according to one aspect of the present invention includes a solvent that polymerizes in the presence of an acid, and a photoacid generator that is dissolved in the solvent and generates an acid upon irradiation with electromagnetic radiation. A method for curing an electromagnetic radiation curable liquid composition containing
Supplying the electromagnetic radiation curable liquid composition on a recording medium to form a composition layer;
Irradiating the composition layer with electromagnetic radiation including a wavelength absorbed by the photoacid generator, generating an acid from the photoacid generator, and curing the composition layer,
When the composition layer is formed, the recording medium is heated so that the temperature of the recording medium is higher than the temperature of the supplied electromagnetic radiation curable composition.

An inkjet recording method according to an aspect of the present invention is an electromagnetic radiation curable type comprising a solvent that polymerizes in the presence of an acid, and a photoacid generator that is dissolved in the solvent and generates an acid upon irradiation with electromagnetic radiation. An ink jet recording method for forming an image on a recording medium by discharging a liquid composition from an ink jet recording head,
A step of conveying the recording medium by a conveying means;
Discharging the electromagnetic radiation curable liquid composition from an ink jet recording head onto the recording medium to form a composition layer;
Irradiating the composition layer with electromagnetic radiation including a wavelength absorbed by the photoacid generator, generating an acid from the photoacid generator, and curing the composition layer,
When the composition layer is formed, the recording medium is heated so that the temperature of the recording medium is higher than that of the electromagnetic radiation curable liquid composition discharged from the inkjet recording head. And

An ink jet recording apparatus according to an aspect of the present invention is an electromagnetic radiation curable type comprising a solvent that polymerizes in the presence of an acid, and a photoacid generator that is dissolved in the solvent and generates an acid upon irradiation with electromagnetic radiation. Means for discharging the liquid composition onto the recording medium by an ink jet recording head;
Means for relatively moving the recording medium and the ink jet head;
Means for heating the recording medium at least by the time when the electromagnetic radiation curable liquid composition is discharged from the ink jet recording head, and the heated electromagnetic radiation curable liquid composition, the photoacid A means for irradiating electromagnetic radiation including a wavelength absorbed by the generator is provided.

  According to one aspect of the present invention, an electromagnetic radiation curable liquid composition comprising a solvent that polymerizes in the presence of an acid, and a photoacid generator that is dissolved in the solvent and generates an acid upon irradiation with electromagnetic radiation. An efficient curable method is provided. According to another aspect of the present invention, an electromagnetic radiation curable liquid composition comprising a solvent that polymerizes in the presence of an acid, and a photoacid generator that is dissolved in the solvent and generates an acid upon irradiation with electromagnetic radiation. Provided are a method for efficiently recording by ejecting an object by ink jet and an apparatus therefor.

  Embodiments of the present invention will be described below.

  In the method according to the embodiment of the present invention, an electromagnetic radiation curable liquid composition containing a solvent that polymerizes in the presence of an acid and a photoacid generator is used. The image forming ability of such a composition depends on the chemical amplification mechanism. First, an acid is generated from the photoacid generator by irradiation with electromagnetic radiation (light irradiation) such as ultraviolet rays, and this acid is diffused by heating to cause a crosslinking reaction. Functions as a catalyst. The electromagnetic radiation irradiated here includes a wavelength absorbed by the photoacid generator. When the acid diffuses, for example, the acid spreads to the portion where the light does not reach due to the influence of the coloring material or the like and the acid is not generated, and the curing is promoted in a wide range.

  In particular, in the ink jet recording method according to the embodiment of the present invention, it is desired that the ink is adjusted to a predetermined viscosity in order to stably eject the ink. For example, the viscosity at 25 ° C. is preferably 50 cp or less, and more preferably 30 cp or less.

  In the composition used in the method according to the embodiment of the present invention, the solvent that is polymerized in the presence of an acid specifically includes an epoxy compound containing an alicyclic skeleton and / or an aliphatic skeleton, a vinyl ether compound, an oxirane. At least one selected from the group consisting of a group-containing compound and an oxetane ring-containing compound can be used. In particular, an acid-polymerizable compound having an alicyclic skeleton and / or an aliphatic skeleton having a viscosity of 50 mPa · s or less at room temperature and normal pressure and a boiling point of 150 ° C. or higher is preferable as the acid-polymerizable solvent.

  Examples of the photoacid generator include onium salts, diazonium salts, quinonediazide compounds, organic halides, aromatic sulfonate compounds, bisulfone compounds, sulfonyl compounds, sulfonate compounds, sulfonium compounds, sulfamide compounds, iodonium compounds, sulfonyldiazomethane compounds, And mixtures thereof can be used.

  The photoacid generator is generally used at a ratio of about 0.5 to 10 parts by weight with respect to 100 parts by weight of the acid-polymerizable solvent. In the case of a 1: 1 mixture with polycarbonate or the like, it is used at a ratio of about 1 to 20 parts by weight with respect to 100 parts by weight of the acid-polymerizable solvent. A more preferable blending amount of the photoacid generator is about 1 part by weight or more and 12 parts by weight or less with respect to 100 parts by weight of the acid polymerizable solvent.

  When a color component is blended in addition to the components described above, an electromagnetic radiation curable UV ink can be obtained. As the color component, a pigment can be used, and it may be either organic or inorganic. The compounding amount of the color component is usually about 0 to 20 parts by weight with respect to 100 parts by weight of the acid polymerizable compound. A more preferable amount of the color component is about 3 parts by weight or more and 6 parts by weight or less with respect to 100 parts by weight of the acid polymerizable compound.

  The electromagnetic radiation curable liquid composition used in the method according to the embodiment of the present invention is obtained by uniformly mixing predetermined components and filtering the mixture using a PTFE filter or the like.

  Next, an ink jet recording apparatus according to an embodiment of the present invention will be described with reference to the drawings.

  FIG. 1 is a diagram schematically showing an ink jet recording apparatus according to an embodiment of the present invention. The ink jet recording apparatus 1 includes a transport unit 3 that transports a recording medium 2. A recording medium temperature adjusting means 7, an ink jet recording head 4, a light irradiation means 5, and a heating means 6 are sequentially arranged from the upstream side to the downstream side along the moving direction of the conveying means 3.

  The recording medium 2 is not particularly limited as long as it is a printable medium. As the recording medium 2, for example, paper, an OHP sheet, a resin film, a nonwoven fabric, a porous film, a plastic plate, a circuit board, a metal substrate, and the like can be used.

  The conveying unit 3 conveys the recording medium 2 so that the recording medium 2 sequentially passes through the front of the recording medium temperature adjusting unit 7, the recording head 4, the light irradiation unit 5, and the heating unit 6. Here, the transport unit 3 transports the recording medium 2 from the right side to the left side in the drawing. The transport unit 3 can be configured by, for example, a belt and / or roller that moves the recording medium 2 and a drive mechanism (not shown) that drives the belt. Further, the conveying means 3 may further be provided with a guide member for assisting the movement of the recording medium 2. Alternatively, the transport means 3 may have a stage structure that slides on a linear base that transports the single-sheet recording medium 2.

  The recording head 4 forms an ink layer by ejecting electromagnetic radiation curable UV ink on the recording medium 2 in response to the image signal. As already explained, the electromagnetic radiation curable UV ink refers to an electromagnetic radiation curable liquid composition containing a color component. As the recording head 4, for example, a serial scanning type head mounted on a carriage or a line scanning type head having a width equal to or larger than the width of the recording medium 2 can be used. From the viewpoint of high-speed printing, the latter is usually more advantageous than the former. There is no particular limitation on the method for discharging the electromagnetic radiation curable UV ink from the recording head 4. For example, it is possible to employ a technique in which ink droplets are ejected using the pressure of vapor generated by the heat of the heating element. Alternatively, ink droplets may be ejected using mechanical pressure pulses generated by a piezoelectric element.

  The light irradiation means 5 irradiates the ink layer on the recording medium 2 with light to generate an acid in the ink layer. Examples of the light irradiation means 5 include mercury lamps such as low, medium and high pressure mercury lamps, tungsten lamps, xenon lamps, arc lamps, excimer lamps, excimer lasers, semiconductor lasers, YAG lasers, lasers and nonlinear optical crystals. A combined laser system, a high frequency induced ultraviolet ray generator, an electron beam irradiation device, an X-ray irradiation device, or the like can be used. In particular, it is desirable to use a high frequency induced ultraviolet ray generator, a high / low pressure mercury lamp, a semiconductor laser, etc., because the system can be simplified. The wavelength when ultraviolet rays are used is preferably about 100 nm to 600 nm. The light output from the light irradiation means 5 is not limited to ultraviolet rays. It can be appropriately selected according to the sensitivity wavelength of the photoacid generator contained in the electromagnetic radiation curable liquid composition or the electromagnetic radiation curable UV ink. In particular, it is more preferable to have a peak in the vicinity of 250 nm or 365 nm. Further, the light irradiating means 5 may be provided with a condensing mirror or a running optical system.

  The heating means 6 heats the ink layer on the recording medium 2 and promotes a crosslinking reaction using an acid generated in the ink layer by irradiation with electromagnetic radiation as a catalyst. For example, an infrared lamp, a halogen heater, a far infrared ceramic heater, a roller (heat roller) with a built-in heating element, a blower that blows hot air or hot air, and the like can be used. In particular, when a metal recording medium is used in a high-speed printing apparatus with a printing speed of several tens of m / min, it is desirable to instantaneously raise the surface temperature of the recording medium. This can be achieved by using a non-contact type condensing halogen heater. Alternatively, a condensing mirror may be provided in the non-contact lamp type heating means 6.

  At this time, the amount of heat given to the recording medium 2 for heating the UV ink layer formed on the recording medium 2 is further determined by determining as follows regardless of the type, material, and thickness of the recording medium. Curing efficiency can be increased. That is, it is desirable to raise the surface peak temperature of the recording medium 2 to at least about 90 ° C. from the initial temperature (the initial temperature of the recording medium preheated by the recording medium temperature adjusting means 7).

  The recording medium temperature adjusting means 7 may be disposed on either the lower side or the upper side of the conveying means 3 and may be either a fixed type or a movable type. Further, either a contact type or a non-contact type may be used. A schematic diagram of an example of an ink jet recording apparatus in a non-contact type is shown in FIG. In the ink jet recording apparatus shown in FIG. 2, a non-contact type recording medium temperature adjusting means 7 is disposed above the conveying means 3.

  In preheating the recording medium 2, it is not always necessary to provide the recording medium temperature adjusting means 7 in the ink jet recording apparatus 1. For example, as shown in FIG. 3, the recording medium preheating stocker 14 can be provided in the front stage of the conveying means 3 of the inkjet recording apparatus 1. The recording medium 2 accommodated in the recording medium preheating stocker 14 is preheated at a predetermined temperature all at once by a heating means (not shown) provided in the recording medium preheating stocker 14. It is transported by the transport means 3. Such a method has a large heat capacity, and the surface temperature is unlikely to decrease instantaneously. This is particularly effective when recording on the recording medium 2 made of a metal having a large density or specific gravity or a material having a large volume such as a thickness.

  In any case, the recording medium temperature adjusting means 7 preheats the recording medium 2 conveyed by the conveying means 3 and raises the recording medium 2 to a predetermined temperature before reaching the recording head 4. Keep it. Furthermore, the effect that the heating of the ink layer on the recording medium 2 by the heating means 6 is promoted by preheating the recording medium 2 is also obtained.

  As the recording medium temperature adjusting means 7, for example, an infrared lamp, a halogen heater, a far-infrared ceramic heater, a roller (heat roller) with a built-in heating element, an IH heater, a blower that blows hot air or hot air, and the like can be used. . When the recording medium 2 is made of metal and is of a non-contact type as shown in FIG. 2, a far infrared ceramic heater is preferable. In the case of a high-speed printing apparatus with a printing speed of several tens of m / min or when it is necessary to instantaneously raise the temperature, the recording medium temperature adjusting means 7 in the non-contact type recording apparatus shown in FIG. It is desirable that the temperature can be increased instantaneously. Specifically, the use of a condensing halogen heater is highly effective. FIG. 4 shows a cross-sectional view of an example of a halogen heater that can be used. As shown in the drawing, the halogen heater 22 is housed in a housing 21 with the periphery covered by a reflecting plate 23. A focal point 24 exists at a predetermined position below the halogen heater 22 and is focused here. Therefore, it is desirable to set the distance at which the halogen heater is disposed so that the recording medium 2 passes through the focal point 24.

A method for printing (image formation) on the recording medium 2 using the inkjet recording apparatus 1 shown in FIG. 1 will be described in detail below.
First, the recording medium 2 is conveyed from the right side to the left side in the drawing by the conveying unit 3. The conveyance speed of the recording medium 2 is appropriately selected according to the purpose of use and is controlled within a range of, for example, about several tens of m / min. When the recording medium 2 is conveyed, the recording medium 2 is preheated by a recording medium temperature adjusting means 7 disposed below the conveying means 3. The preheating range by the recording medium temperature adjusting means 7 can be up to the vicinity of the position where an image is formed by the recording head 4 as shown in FIG. Alternatively, as shown in FIG. 5, it may be up to the vicinity of a position in front of the heating means 6 that is irradiated with electromagnetic radiation (light irradiation) such as ultraviolet rays by the light irradiation means 5.

  Specific ranges for the preheating include the curing sensitivity of the electromagnetic radiation curable liquid composition and UV ink, the moving speed of the printing surface (the conveying speed of the recording medium 2), and the type (material, The thickness can be appropriately set according to the thickness). However, the temperature of the recording medium 2 when it reaches the recording head 4 needs to be higher than the temperature of the ink ejected from the recording head 4. The temperature of the ejected ink is usually about 20 to 60 ° C., and if the temperature of the recording medium 2 is about the same or lower than that, the ink layer cannot be cured efficiently. For this reason, the optimal irradiation conditions required for ink curing by electromagnetic radiation irradiation (light irradiation) are limited to a narrow range.

  The preheating temperature of the recording medium 2 to be conveyed may be a temperature that does not hinder the effect of heating by the heating means 6 described later. This temperature is desirably high as long as it does not cause deformation of the recording medium 2. It is necessary that the heat radiated from the light irradiation means is efficiently given to the ink without being taken away by the recording medium conveying means or the like. It is preferable that the acid required for curing is sufficiently diffused to the deep part of the ink layer and the temperature is raised before irradiation with electromagnetic radiation (light irradiation) to a temperature at which uniform curing is possible. Therefore, recording is performed in such a range that the effect of enabling uniform curing by sufficiently diffusing the acid necessary for curing to the deep part of the ink layer to such an extent that heating after light irradiation is not required. The medium 2 is preheated. Actually, it is desirable to set a preheating condition by conducting an experiment in advance to evaluate the curing characteristics of the ink. Specifically, although it depends on the composition of the ink, the ink temperature, the material of the recording medium, and the like, it can be within a range of 35 to 120 ° C., more preferably about 50 to 70 ° C.

  When the recording medium 2 is conveyed to the front of the recording head 4, the recording head 4 ejects electromagnetic radiation curable UV ink corresponding to the image signal. As a result, an ink layer is formed on the recording medium 2.

The recording medium 2 on which the ink layer is formed is conveyed to the front of the light irradiation means 5. When the recording medium 2 passes through the front of the light irradiation means 5, the light irradiation means 5 emits light toward the ink layer to generate an acid in the ink layer. The irradiation light intensity at the position of the ink layer surface varies depending on the wavelength of the light source used, but is usually in the range of several mW / cm ^{2 to} 10 W / cm ² . The irradiation light intensity is preferably in the range of about several tens of mW / cm ^{2 to 5} W / cm ² . The exposure amount to the ink layer can be appropriately set according to the sensitivity of the ink, the moving speed of the printing surface (conveying speed of the recording medium 2), and the like.

  Subsequently, the recording medium 2 is conveyed into or near the heating means 6. When the recording medium 2 passes through or in the vicinity of the heating unit 6, the heating unit 6 heats the ink layer formed on the recording medium 2 and promotes a crosslinking reaction in the ink layer. In the ink jet recording apparatus 1 shown in FIG. 1, the heating time by the heating means 6 is usually 0. It is relatively short, from several seconds to several tens of seconds. Therefore, when the ink layer is cured almost completely by the heating means 6, the heating is performed so that the maximum temperature reaches a relatively high temperature of, for example, about 200 ° C. or less, particularly about 80 ° C. to 200 ° C. Is desired. Or it is good also as a temperature range about 60 to 180 degreeC.

  The heating by the heating means 6 can be omitted by optimizing the ink composition or the above-described preheating and irradiation conditions of electromagnetic radiation. Thereafter, the recording medium 2 is conveyed into a stocker (or container) (not shown), and printing is completed.

  The heating means 6 for heating the ink layer is not limited to the heating means 6 disposed downstream of the light irradiation means 5 as shown in FIG. For example, a stocker 15 having heating means as shown in FIG. 6 can be used. The recording medium 2 after exposure can be accommodated in the stocker 15 provided with such heating means, and heating can be performed collectively. Alternatively, when the ink layer is exposed, the light irradiation means 5 may be used as a heat source by bringing the light irradiation means 5 closer to the recording medium 2 to the extent that the printing surface is not damaged. The light source may be used as a heat source by not providing the light source with a heat removal mechanism such as a cold mirror. In the case of a high-power valve of several hundred watts, since it has a cooling mechanism at the same time, a mechanism for intentionally reducing the heat to the recording medium 2 is provided by changing a part of the exhaust heat mechanism. Thereby, the ink layer can be heated by the heat generated from the light irradiation means 5.

  More specifically, the light irradiation means 5 having an output of 100 watts or more having a mechanism used for heating by re-introducing the airflow having cooled the light irradiation means 5 into the recording medium 2 or the transport / holding mechanism corresponds to this. . The temperature reached by the recording medium 2 due to the reduction of the heat of the light irradiation means 5 may be a temperature at which the same effect as the heating by the heating means 6 described above is obtained. The preferred temperature varies depending on the heating time, but is usually at least 60 ° C or higher, more preferably 80 ° C to 100 ° C. Further, when the exposure speed is as high as several meters / second, since it is heated instantaneously, the temperature may be as high as about 180 ° C.

  For example, when a light irradiation means 5 that can generate infrared light in addition to visible light is used, heating can be performed simultaneously with the light irradiation. In this case, since hardening can be accelerated | stimulated, it is preferable.

  In addition, when the color component contained in the electromagnetic radiation curable UV ink discharged from the recording head 4 is extremely small, it can be referred to as an electromagnetic radiation curable liquid composition having high transparency. For this reason, electromagnetic radiation irradiation (light irradiation) light such as ultraviolet rays irradiated by the light irradiation means 5 can easily reach the deep part of the liquid composition layer. As a result, the irradiation output of the light irradiation means 5 can be reduced. It is possible to reduce the temperature (output: required heat amount) of the heating means 6, which leads to miniaturization. Further, depending on the conditions, the liquid composition layer can be sufficiently cured by the radiant heat output simultaneously with the light from the light irradiation means 5 in addition to the preheating of the recording medium temperature adjusting means 7. In this case, the heating after the light irradiation is not necessarily performed, and the heating means 6 can be omitted as shown in FIG. As a result, the inkjet recording apparatus 1 can be downsized.

  When an electromagnetic radiation curable UV ink containing a color component is used, the electromagnetic radiation irradiated light irradiated by the light irradiation means 5 has a liquid composition as compared with the liquid composition layer having a high transparency described above. It is difficult to reach the deep part of the material layer. When the thickness of the composition layer to be formed is thick, it is particularly difficult for light to reach the deep part, and it is necessary to consider the amount of the photoacid generator contained in the UV ink. In the recording apparatus according to the embodiment of the present invention, since the recording medium 2 is preheated by the recording medium temperature adjusting means 7 and the acid necessary for curing is sufficiently diffused to the deep part of the ink layer, the temperature of the heating means 6 ( (Output: necessary heat quantity) can be reduced, leading to downsizing of the device. Further, depending on conditions, the electromagnetic radiation curable UV ink layer can be sufficiently cured by only the radiant heat output simultaneously with the light from the light irradiation means 5 in addition to the preheating of the recording medium temperature adjusting means 7. . In this case, heating after light irradiation is not necessary, and the heating means 6 can be omitted as in the case of the electromagnetic radiation curable liquid composition having high transparency. In this case, as described with reference to FIG. 7 or FIG. 8, the ink jet recording apparatus 1 can be downsized.

  The ink jet recording apparatus 1 according to the embodiment of the present invention may be a flat bed type ink jet recording apparatus. A schematic diagram of an example is shown in FIG. In the illustrated ink jet recording apparatus, the recording medium 2 is fixed, and the ink jet recording head 4 and the light irradiation means 5 are moved to form an image. Below the recording medium fixing stage, a recording medium temperature adjusting means 7 is disposed, and the entire recording medium 2 is preheated to form an image.

  The ink jet recording apparatus 1 includes an ink jet recording head 4, a light irradiation unit 5, and a heating unit 6 as an ink jet recording unit. Recording is performed by the recording head 4 reciprocating serially on the recording medium 2 fixed on a recording medium fixing stage (not shown).

  The ink jet recording unit is fixed to one by the guides 8 and 9 on both sides, and at the same time, is reciprocated on the front rail 10 and the rear rail 11 arranged in parallel in the directions of the white arrow and the black arrow. Configured as follows. The conveying method can be performed by pulling with a wire attached to a stepping motor or the like. Alternatively, it may be self-moving like a linear slider.

  The front rail 10 and the rear rail 11 are fixed in parallel, and are configured to be conveyed in the direction of the arrow on the left rail 12 and the right rail 13 that are arranged in parallel outside the recording medium 2.

  When ink jet recording is performed in such a configuration, the ink jet recording unit forms an image on the recording medium 2 while being conveyed in the direction of the white arrow as shown in the figure. After completion of the one-way image formation, the ink jet recording unit is temporarily returned in the black arrow direction while the left rail 12 and the light rail 13 arranged in parallel are unrecorded on the recording medium 2 in the black arrow direction. Moved to the part. Next, an image is formed on the recording medium 2 while being conveyed in the direction of the white arrow in the same manner. By repeating this operation, an image is formed on the large recording medium 2.

  Even in such a flatbed type ink jet recording apparatus, the recording medium temperature adjusting means 7 preheats the recording medium 2 in the same manner as the ink jet recording apparatus 1 as described above, thereby reducing the size of the heating means 6. Can be expected.

Hereinafter, embodiments of the present invention will be described in more detail with reference to specific examples.
An electromagnetic radiation curable liquid composition and an electromagnetic radiation curable UV ink were prepared, and their curing characteristics were examined. In preparing the composition, first, the following two epoxy compounds Ep1 and Ep2 were mixed at a weight ratio of 7: 1 to obtain an acid polymerizable composition (epoxy composition) a.

Ep1: 1,2: 8,9 diepoxy limonene Ep2: ε-caprolactone modified 3,4-epoxycyclohexylmethyl
3 ', 4'-epoxycyclohexanecarbochelate The carbon black pigment as the color component was kneaded with an acrylic resin in an amount corresponding to 5% by weight. This kneaded material and 200 ppm nonionic surfactant (manufactured by Sumitomo 3M) were added to the epoxy composition a described above. Then, these mixtures were subjected to dispersion treatment with a paint shaker for a whole day and night to obtain a black composition a (B).

The black composition a (B) and the photoacid generator were mixed and stirred at the ratio shown in Table 1 below. The obtained mixture was filtered through a 5 μm PTFE filter to obtain sample compositions (1) and (2). The sample composition (1) is an electromagnetic radiation curable liquid composition, and the sample composition (2) is an electromagnetic radiation curable UV ink (hereinafter referred to as UV ink).

Here, PAG3 used as a photoacid generator is a solution obtained by dissolving an equal mixture of compounds PAG1 and PAG2 represented by the following chemical formula in propylene carbonate at a concentration of 50%. This is commercially available as UVACURE1591 (manufactured by Daicel UCB).

  Using the inkjet recording apparatus 1 shown in FIG. 1, sample compositions (1) and (2) were printed, and their curing characteristics were examined. Each member of the inkjet recording apparatus 1 was prepared as follows. As the conveying means 3, a metal endless belt having high heat resistance and low heat capacity was used, and was arranged in a state where tension was applied between a driving roller and a driven roller. The recording head 4 is a CB1 inkjet recording head manufactured by Toshiba Tec Corporation, and the light irradiation means 5 is a UV irradiation system HP6 (D bulb: peak wavelength 350 nm to 390 nm manufactured by Fusion UV Systems Japan Co., Ltd.). ) Was used. Further, as the heating means 6, a far infrared ceramic heater PLC-32 series manufactured by Noritake Company Limited was used. The recording medium temperature adjusting means 7 is a means for carrying a silicon rubber heater manufactured by OM Heater Co., Ltd. on a heat-resistant resin plate-like member having a low thermal conductivity, such as a POM board, from the paper feeding position to the light irradiation means 5 position. 3 was placed close to the bottom.

  The printing conditions for all samples were as follows.

Recording head 4 resolution: 600 dpi,
Discharge volume: 42 pl / per nozzle Printing speed (conveying speed of belt as recording medium conveying means): 25 m / min
Radiation output Large: 2600mW / cm ^2, the irradiation output small 1800mW / cm ²
Heating temperature (recording medium surface temperature): 100 ° C. (passing time: about 5 seconds)
Preheating temperature: 60 ° C
The irradiation output is a value measured by using a UV intensity meter (industrial UV checker UVR-T1) manufactured by Topcon Co., Ltd., which indicates UV illuminance. This illuminance was adjusted by an output adjustment knob (volume) of a UV irradiation system HP6 manufactured by Fusion UV Systems Japan, which is a light irradiation means.

  Under the conditions described above, each composition was printed on a PET (thickness: 200 μm) sheet as a recording medium, and the height after curing was measured by a pencil hardness method. The curability (hardness) of the printed image was measured in accordance with Japanese Industrial Standard JIS K5600-5-4 (using pencils 2B to 2H made by MITSU-BISHI), and was classified into 4 stages A to D as follows. Judged by. The results obtained for sample compositions (1) and (2) are summarized in Tables 2 and 3 below, respectively.

A: H or higher
B: F
C: B and HB
D: 2B

  As shown in Table 2, in the case of an electromagnetic radiation curable liquid composition, the heat radiated from the light irradiation means is generated by preheating the liquid composition layer formed on the surface of the recording medium. The ink is efficiently given to the ink without being taken away by the transport means. As a result, the acid necessary for curing is sufficiently diffused to the deep part of the ink layer to allow uniform curing, and heating after light irradiation is not necessary.

  Also in the case of UV ink, by pre-heating as shown in Table 3, the heat from the heating means is not taken away by the recording medium conveying means and the UV ink formed on the surface of the recording medium. Efficiently fed into the layer. In this way, the acid required for curing is sufficiently diffused to the deep part of the ink layer, and uniform curing is possible. As a result, the heating means after light irradiation can be simplified, downsized, or reduced in output. In some cases, the heating means after the light irradiation can be omitted.

  Thus, by preheating the recording medium and thereby preheating the electromagnetic radiation curable liquid composition layer, energy radiated from the light irradiation means for irradiating electromagnetic radiation (usually light and heat), In addition, it is possible to make maximum use of the heat given from the heating means. That is, only a small preheating means is sufficient for the ink jet recording apparatus, and a large heating apparatus is not necessary, leading to compactness of the apparatus. Furthermore, preheating also has the effect of reducing the viscosity of the ink adhering to the recording medium, improving the wettability with the recording medium and improving the adhesion between the ink layer and the recording medium.

Furthermore, the following UV inks were prepared and examined for curability under each condition.
In preparing the UV ink, first, the above-described epoxy compound Ep1 (1, 2: 8,9 diepoxy limonene) and the following epoxy compound Ep3 (neopentyl glycol diglycidyl ether) are 1: 1 (weight ratio). ) To obtain an acid polymerizable composition (epoxy composition) b. The epoxy compound Ep1 is Celoxide 3000 (manufactured by Daicel Chemical Industries), and the epoxy compound Ep3 is SR-NPG (manufactured by Sakamoto Pharmaceutical Co., Ltd.).

  The carbon black pigment as the color component was kneaded with an acrylic resin in an amount corresponding to 4% by weight. This kneaded material and 200 ppm nonionic surfactant (manufactured by Sumitomo 3M) were added to the epoxy composition b described above. Thereafter, the mixture was dispersed by a paint shaker for a whole day and night to obtain a black composition b (B).

The black composition b (B) and the photoacid generator were mixed and stirred at the ratio shown in Table 4 below. The obtained mixture was filtered through a 5 μm PTFE filter to obtain a sample composition (3). Sample composition (3) is a UV ink.

Here, PAG6 used as a photoacid generator is a solution obtained by dissolving an equal mixture of compounds PAG4 and PAG5 represented by the following chemical formula in propylene carbonate at a concentration of 50%. This is commercially available as ESACURE 1064 (Lamberti).

  A sample composition (3) was printed using the inkjet recording apparatus 1 shown in FIG. 1, and the curing characteristics thereof were examined. Each member of the inkjet recording apparatus 1 was prepared as follows. As the conveying means 3, a metal endless belt having high heat resistance and low heat capacity was used, and was arranged in a state where tension was applied between a driving roller and a driven roller. The recording medium 2 can be fixed to a part of the surface of the endless belt only during printing. As the recording head 4, a CB1 ink jet recording head manufactured by Toshiba Tec Corporation was used. As the light irradiation means 5, a condensing type UV irradiation system LH-6 (D bulb: peak wavelength 350 nm to 390 nm, standard reflection mirror) manufactured by Fusion UV Systems Japan Co., Ltd. is used. , And disposed at a position about 417 mm away in the transport direction.

  As the heating means 6, a halogen heater unit NIL series (light collecting mirror surface gold plating) manufactured by Infridge Industries Co., Ltd. was used. One or a plurality of heating means 6 are arranged at a position about 417 mm away from the light irradiation means 5 in the transport direction. The heating means used here is a halogen heater as shown in the cross-sectional view of FIG. 4, and the light is condensed at a position 25 mm below the heating means and has a focal point 24. The recording medium temperature adjusting means 7 was produced by sticking a silicon rubber heater manufactured by OHM Heater Co., Ltd. to a heat-resistant resin plate member having a low thermal conductivity, for example, a POM plate. The recording medium 2 is preliminarily heated by being arranged close to the lower part of the conveying unit 3 from the paper feeding position to the light irradiation unit 5 position.

  The recording medium temperature adjusting means 7 is not limited to the above-described configuration, and may be a non-contact type using radiant heat or a type of blowing warm air. The non-contact type may be a halogen heater unit NIL series (condensing mirror surface gold plating) manufactured by Infridge Industries Co., Ltd. using the heating means 6. When the recording medium 2 is a metal such as iron, a self-heating element such as electromagnetic induction heating can be used as the recording medium temperature adjusting means.

  The printing conditions (ink curing film creation conditions) relating to this example were as follows.

Recording head 4 resolution: 600 dpi,
Discharge volume: per 42 pl / 1 nozzle Discharged ink temperature by the recording head 4: about 40 ° C. Ink film thickness: about 5-6 μm (during solid image printing)
Printing speed (recording medium conveying speed by the recording medium conveying means 3): 25 m / min
Further, as the light irradiation means 5, ultraviolet rays having a peak near the wavelength of 365 nm were used, and the output range was appropriately changed within the following range.

Light irradiation illuminance: 263 mW / cm ^{2 to} 2429 mW / cm ²
Integrated amount of light irradiation: 4 mJ / cm ^{2 to} 236 mJ / cm ²
The heating means 6 set the heating conditions by appropriately changing the heater output per 1 cm of the halogen lamp in the longitudinal direction within a range of 0.117 to 0.936 KW / cm.

  Using the inkjet recording apparatus 1 having the above-described configuration, a solid image cured product was produced from the sample composition (3) on a stainless metal plate (thickness: about 100 μm) as the recording medium 2. In printing, the recording medium 2 was conveyed at a speed of 25 m / min, and various conditions such as the light irradiation illuminance and light amount of the light irradiation means 5 and the heater output of the heating means 6 were changed.

  The light irradiation output (illuminance / integrated light amount) of the light irradiation means 5 is measured using a UV intensity meter (industrial UV checker UVR-T1, light receiving unit: UD-T36, peak sensitivity wavelength: about 350 nm) manufactured by Topcon. It is the value. The irradiation output was adjusted in a range of 25 to 100% by the output adjustment knob (volume) of the UV irradiation system.

  At that time, when the recording medium 2 is not preheated by the recording medium temperature adjusting means 7 described in the ink jet recording apparatus 1 (the temperature of the recording medium 2 is about 30 ° C.) and when the preheating is performed (the temperature of the recording medium 2 is 50 ° C.). C.), the curability of the cured product on the recording medium 2 was examined. As curability, tack-free property and pencil hardness were measured.

  The tack-free property means that the ink is reversely transferred to the back surface of the recording medium 2 when two printed recording media are stacked. Tack-free means that the ink on the recording medium 2 is not reversely transferred to the back surface of the recording medium 2 when two printed recording media are overlapped, and can be determined by the following test. Specifically, the ink cured film formed on the recording medium 2 is rubbed several times with a Crecia Kimwipe (paper wiper) to determine the tack-free property of the ink cured film. The tack-free property was evaluated according to the following criteria.

    ○: Tack-free ... Cannot be removed even if rubbed with Kimwipe 5 times.

    Δ: Slightly tack-free ... Adheres when rubbed with Kimwipe 5 times.

X: Not tack-free ... It adheres when rubbed once with Kimwipe. (Hardening failure)
That is, if tack-free, it can be determined that the UV ink layer on the recording medium 2 is substantially cured.

  The pencil hardness was measured in accordance with Japanese Industrial Standard JIS K5600-5-4 (using pencils 2B to 2H manufactured by MITSU-BISHI). In the combination of UV ink and recording medium 2 (stainless metal plate) used in this example, the pencil hardness is required to be “H” or higher.

Table 5 shows the results without preheating, and Table 6 shows the results with preheating. In the upper row of each column, the middle row is curable tack-free property, and the lower row is pencil hardness. A curing condition range in which tack-free property is “◯” and pencil hardness is “H” or more is an appropriate condition range.

As shown in Table 5, when the recording medium 2 is not preheated, the illuminance and light intensity of the light irradiation means 5 are set to 2119 mW / cm ² or more and 203 mJ / sec, respectively, in order to ensure tack-free property “◯”. cm ² and more, heaters output of the heating means 6, it is necessary to 0.195KW / cm or more. In order to ensure a pencil hardness of “H” or higher, the illuminance and light intensity of the light irradiation means 5 are set to 2119 mW / cm ² or more and 203 mJ / cm ² or more, respectively, and the heater output of the heating means 6 is 0.468 KW / It is necessary to set it to cm or more. For this reason, when the recording medium is not preheated, the appropriate condition range for obtaining a good cured product is extremely narrow.

On the other hand, when the recording medium 2 is preheated in the temperature range of 35 ° C. to 120 ° C., the appropriate condition range is greatly expanded as shown in Table 6. That is, in order to ensure tack-free property “◯”, the illuminance and light intensity of the light irradiation means 5 are set to 1191 mW / cm ² or more and 104 mJ / cm ² or more, respectively, and the heater output of the heating means 6 is 0.117 kW / What is necessary is just to be cm or more. Further, in order to ensure a pencil hardness of “H” or higher, the heater output of the heating means 6 may be 0.146 KW / cm or higher.

  As described above, it was confirmed that by preheating the surface of the recording medium 2 above the temperature of the ink ejected from the head 4, the proper curing conditions are significantly wider than when the recording medium 2 is not preheated. In this embodiment, the temperature of the recording medium 2 (surface) is about 30 ° C., which is around room temperature in the inkjet recording apparatus 1, and the temperature of the UV ink ejected from the inkjet recording head 4 is about 40 ° C. It was. As shown in the above results, a sufficient effect can be obtained by increasing the temperature of the recording medium 2 (surface) by about 20 ° C. to 50 ° C., for example.

  When compared under equivalent light irradiation conditions, a remarkable effect cannot be expected when the output of the heating means 6 is increased so that the surface peak temperatures of the recording medium 2 are equivalent. By preheating the recording medium 2 and increasing the surface temperature of the recording medium 2 above the temperature of the ink ejected from the head 4, it becomes possible to promote the curing of the ink. Such an effect can be obtained even when the surface temperature of the recording medium 2 is about the same.

Further, under the light irradiation conditions of the light irradiation means 5 with an illuminance of 1191 mW / cm ² or more and a light quantity of 104 mJ / cm ² or more, the recording medium 2 surface peak temperature preliminarily heated by the recording medium temperature adjusting means 7 is about 35 to 120 ° C. If it is within the range, the same curability result can be obtained. Although the temperature of the UV ink ejected from the recording head 4 is somewhat affected, when the surface temperature of the recording medium 2 preheated by the recording medium temperature adjusting means 7 is higher than the ejection temperature of the UV ink, the preheating temperature Curability was good in the range of about 35 to 120 ° C.

  When the temperature is lower than 35 ° C., the effect of preheating the recording medium 2 in curability cannot be obtained sufficiently. On the other hand, when the temperature exceeds 120 ° C., the recording medium 2, UV ink, and ink jet recording apparatus 1 are often damaged, and the influence on image quality such as image unevenness related to image formation on the recording medium 2 is large. Furthermore, the problem that the energy consumption of the apparatus regarding preheating also became large occurred.

  When the temperature of the UV ink ejected from the recording head 4 is about 40 ° C., the recording medium 2 preheating temperature by the recording medium temperature adjusting means 7 is more effective if the temperature is in the range of about 50 to 70 ° C. Can be obtained. Due to image quality, damage to the recording medium 2, and the like, when the recording medium 2 preheating temperature by the recording medium temperature adjusting means 7 is about 50 to 70 ° C., the curability of the UV ink layer on the recording medium 2 is remarkably excellent. confirmed.

  In addition, the following effects can be obtained by preheating the recording medium 2. For example, when the temperature of the UV ink is 40 ° C., the viscosity of the ink is lowered by preheating the recording medium 2 in the range of about 50 to 70 ° C. by the recording medium temperature adjusting means 7. When the viscosity of the ink is reduced to, for example, 20 mPa · s (cp) or less, the acid generated in the ink can be diffused more efficiently. As a result, the curability is also improved and the effect is enhanced. Furthermore, by reducing the ink viscosity, the wettability with the surface of the recording medium 2 is also improved, and the adhesion between the cured product and the surface of the recording medium 2 is also improved.

  In order to secure tack-free property “◯”, the total amount of heat necessary for raising the temperature of the UV ink or the recording medium 2 is determined as follows. That is, including all of the preliminary heating by the recording medium temperature adjusting means 7, the heating by the light irradiation means 5, the heating by the heating means 6, etc., the PET having a thickness of 100 μm is at least raised from the initial temperature to the minimum necessary temperature for curing. There is a need to. Here, the initial temperature is about 50 ° C., and the minimum temperature required for curing is about 90 ° C.

  Since the material of the recording medium indirectly used for measuring the surface temperature in the above-described embodiment is PET, the specific gravity (m) is 1.3 and the specific heat (c) is 1.3 (J / g ° C.). Then, the heat quantity Q required to raise the temperature by about 40 ° C. (90 ° C.-50 ° C.) per 1 g is calculated as follows from Q = mct.

Q = 1.3 × 1.3 × 40 = 67.6J
When the thickness of the PET sheet is 100 μm, the necessary heat quantity Q ′ per 1 cm ² can be Q ′ = 0.676 (J / cm ² ). Accordingly, the minimum conditions necessary for curing the UV ink film on the recording medium 2 are at least about 1000 mW / cm ^{2 in} illuminance, about 100 mJ / cm ² in light quantity, and about 0.676 J / cm ² in heat.

  However, if the thickness of the recording medium 2 exceeds 1 mm, the amount of heat required to cure the ink film on the medium diffuses in the thickness direction of the recording medium. A calorie is required. That is, including the preliminary heating by the recording medium temperature adjusting means 7, the heating by the light irradiation means 5, the heating by the heating means 6, etc., the minimum temperature required for curing (90 ° C.) from the initial temperature of the recording medium 2 (about 50 ° C.). The amount of heat necessary to raise the temperature to a certain extent) must be supplied.

  In addition, the curing process of the UV ink according to the embodiment of the present invention depends on the chemical amplification mechanism, and first, acid is generated from the photoacid generator in the UV ink by irradiation with electromagnetic radiation (light irradiation) such as ultraviolet rays. This acid diffuses in the UV ink by heating and functions as a catalyst for the crosslinking reaction. Due to the diffusion of the acid, for example, the acid spreads to the portion where the light does not reach due to the influence of the coloring material or the like and the acid is not generated, and the curing of the UV ink is promoted in a wide range.

  When a UV ink having a high viscosity is used, in order to obtain an optimum viscosity for ejection, the UV ink is usually heated in the inkjet recording head 4 to lower the viscosity, and adjusted to an optimum viscosity for ejection. When the UV ink heated by the ink jet recording head 4 reaches the surface of the recording medium 2 lower than the temperature, the viscosity is increased by being cooled. Thereafter, even if an acid is generated from the photoacid generator by electromagnetic radiation irradiation (light irradiation), the acid cannot efficiently diffuse in the ink layer. As a result, the curing efficiency of the ink layer deteriorates, and a larger amount of heat is required to re-diffuse the acid by subsequent heating.

  Therefore, after the UV ink layer is irradiated (light irradiation) with the electromagnetic radiation, the highest temperature reached on the surface of the recording medium when the recording medium is heated by the heating process is the highest on the surface of the recording medium when the electromagnetic radiation is irradiated. It is desirable that it be at least higher than the ultimate temperature. In this case, since the acid generated from the photoacid generator by light irradiation is more efficiently diffused, the curing efficiency is further enhanced. The method according to the embodiment of the present invention makes this possible by preheating the recording medium.

1 is a schematic view of an ink jet recording apparatus according to an embodiment of the present invention. FIG. 6 is a schematic view of an ink jet recording apparatus according to another embodiment of the present invention. FIG. 6 is a schematic view of an ink jet recording apparatus according to another embodiment of the present invention. FIG. 3 is a schematic view of a non-contact type condensing halogen heater used in the ink jet recording apparatus shown in FIG. 2. FIG. 6 is a schematic view of an ink jet recording apparatus according to another embodiment of the present invention. FIG. 6 is a schematic view of an ink jet recording apparatus according to another embodiment of the present invention. FIG. 6 is a schematic view of an ink jet recording apparatus according to another embodiment of the present invention. FIG. 6 is a schematic view of an ink jet recording apparatus according to another embodiment of the present invention. FIG. 6 is a schematic view of an ink jet recording apparatus according to another embodiment of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Inkjet recording apparatus; 2 ... Recording medium, 3 ... Conveyance means; 4 ... Recording head 5 ... Light irradiation means; 6 ... Heating means; 7 ... Recording medium temperature adjustment means; 8 ... Guide 9 ... Guide; 11 ... Rear rail; 12 ... Left rail 13 ... Right rail; 14 ... Recording medium preheating stocker.

Claims (20)

A method for curing an electromagnetic radiation curable liquid composition comprising a solvent that polymerizes in the presence of an acid, and a photoacid generator that is dissolved in the solvent and generates an acid upon irradiation with electromagnetic radiation,
Supplying the electromagnetic radiation curable liquid composition on a recording medium to form a composition layer;
Irradiating the composition layer with electromagnetic radiation including a wavelength absorbed by the photoacid generator, generating an acid from the photoacid generator, and curing the composition layer,
When the composition layer is formed, the recording medium is heated so that the temperature of the recording medium is higher than the temperature of the supplied electromagnetic radiation curable composition. A method for curing a linear curable liquid composition.   The method for curing an electromagnetic radiation curable liquid composition according to claim 1, wherein the electromagnetic radiation curable liquid composition further contains a pigment as a color component.   The maximum temperature reached on the surface of the recording medium after irradiating the composition layer with electromagnetic radiation is higher than the maximum temperature reached on the surface of the recording medium when irradiated with the electromagnetic radiation. Item 3. A method for curing an electromagnetic radiation curable liquid composition according to Item 1 or 2.   The amount of heat greater than the amount necessary to diffuse the acid generated from the photoacid generator contained in the electromagnetic radiation curable liquid composition into the composition layer and cure the composition layer is recorded in the recording medium. The method for curing an electromagnetic radiation curable liquid composition according to any one of claims 1 to 3, wherein the composition is applied to the composition layer on a medium.   The method for curing an electromagnetic radiation curable liquid composition according to any one of claims 1 to 4, wherein the recording medium is heated by a non-contact type heating means.   The method for curing an electromagnetic radiation curable liquid composition according to any one of claims 1 to 5, wherein the recording medium is made of metal. An electromagnetic radiation curable liquid composition containing a solvent that is polymerized in the presence of an acid and a photoacid generator that is dissolved in the solvent and generates an acid upon irradiation with electromagnetic radiation is ejected from an ink jet recording head to form a recording medium An inkjet recording method for forming an image on a substrate, comprising:
A step of conveying the recording medium by a conveying means;
Discharging the electromagnetic radiation curable liquid composition from an ink jet recording head onto the recording medium to form a composition layer;
Irradiating the composition layer with electromagnetic radiation including a wavelength absorbed by the photoacid generator, generating an acid from the photoacid generator, and curing the composition layer,
When the composition layer is formed, the recording medium is heated so that the temperature of the recording medium is higher than that of the electromagnetic radiation curable liquid composition discharged from the inkjet recording head. An inkjet recording method.   8. The ink jet recording method according to claim 7, wherein the electromagnetic radiation curable liquid composition further contains a pigment as a color component.   The maximum temperature reached on the surface of the recording medium after irradiating the composition layer with electromagnetic radiation is higher than the maximum temperature reached on the surface of the recording medium when irradiated with the electromagnetic radiation. Item 9. The ink jet recording method according to Item 7 or 8.   The amount of heat greater than the amount necessary to diffuse the acid generated from the photoacid generator contained in the electromagnetic radiation curable liquid composition into the composition layer and cure the composition layer is recorded in the recording medium. The ink jet recording method according to claim 7, wherein the ink composition is applied to the composition layer on a medium.   The inkjet recording method according to claim 7, wherein the recording medium is heated by a non-contact type heating unit.   The inkjet recording method according to claim 7, wherein the recording medium is made of metal. An electromagnetic radiation curable liquid composition containing a solvent that polymerizes in the presence of an acid and a photoacid generator that is dissolved in the solvent and generates an acid upon irradiation with electromagnetic radiation is applied to the recording medium by an inkjet recording head. Means for discharging,
Means for relatively moving the recording medium and the ink jet head;
Means for heating the recording medium at least by the time when the electromagnetic radiation curable liquid composition is discharged from the ink jet recording head, and the heated electromagnetic radiation curable liquid composition, the photoacid An ink jet recording apparatus comprising means for irradiating electromagnetic radiation including a wavelength absorbed by the generator.   The inkjet recording apparatus according to claim 13, wherein the electromagnetic radiation curable liquid composition further contains a pigment as a color component.   The maximum temperature reached on the surface of the recording medium after irradiating the composition layer with electromagnetic radiation is higher than the maximum temperature reached on the surface of the recording medium when irradiated with the electromagnetic radiation. Item 15. The ink jet recording apparatus according to Item 13 or 14.   The amount of heat greater than the amount necessary to diffuse the acid generated from the photoacid generator contained in the electromagnetic radiation curable liquid composition into the composition layer and cure the composition layer is recorded in the recording medium. The ink jet recording apparatus according to claim 13, wherein the ink composition is applied to the composition layer on a medium.   17. The ink jet recording apparatus according to claim 13, wherein the means for heating the recording medium is a non-contact type heating means.   The inkjet recording apparatus according to claim 13, wherein the recording medium is made of metal.   The ink jet recording apparatus is a flat bed type, and the ink jet recording head, the light irradiation means, and the recording medium heating means constitute an ink jet recording unit, and the ink jet recording unit is perpendicular to the recording medium feeding direction. The ink jet recording apparatus according to claim 13, wherein the ink jet recording apparatus is a serial type that operates in a continuous manner.   20. The ink jet recording apparatus according to claim 13, wherein the means for heating the composition layer on the recording medium includes at least one non-contact type condensing halogen heater. .

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