JP5146824B2 - Adhesive transfer liquid developer - Google Patents

Description

  The present invention comprises a toner containing a colorant and a liquid in which the toner is dispersed, and the latent image is developed on the latent image carrier by developing the latent image by attaching the toner to the latent image on the latent image carrier. The present invention relates to a liquid developer used in an image forming method for transferring a toner image with the adhesive force of toner.

Today, as consumers' needs are diversifying, the tendency to demand a small quantity and a wide variety of production is also becoming more prominent. As a method for meeting such a demand, an electrophotographic method that does not require a costly and time-consuming plate making process has attracted attention.
With the development of digital latent image forming technologies such as LEDs and laser beams in electrophotography, it is possible to write high-definition dot images such as 1200 DPI. An image forming method and apparatus capable of forming a fine and high quality image is desired. In order to obtain such a high-quality print, accurate reproducibility of the dot area is necessary. Toner scattering during transfer of a toner image from a latent image carrier or intermediate transfer member to an intermediate transfer member or recording medium is required. Crushing (which occurs even with heat and pressure fixing) is a major problem especially in color printing.
A high-resolution toner image can be realized by reducing the particle size of the toner used. In addition, if toner with a fine particle size is used, the thickness of the toner image is reduced and the color expression in the case of obtaining a color print by color superposition is improved, and the toner image transferred onto the transfer paper as the final recording medium As the thickness of the toner is reduced in accordance with the particle diameter, the degree of curling of the transfer paper and the cracking of the toner image are also improved. As the toner, there are a powder toner used in a dry development system by friction charging with a powder carrier or the like, and a toner (hereinafter referred to as a liquid toner) used in a liquid development system by being dispersed in a solvent as a liquid carrier.

Among these, when the powder toner is a fine powder toner having a particle size on the order of 5 microns to submicron, it is difficult to suppress the toner scattering and to remove the residual toner on the photoreceptor as a latent image carrier after the transfer process. There's a problem. On the other hand, since the liquid toner is used by being dispersed in a solvent, such a problem does not occur and handling as a fine toner is easy. Therefore, compared with dry electrophotography using powder toner, it can achieve high definition as high as a method capable of printing high-definition images such as gravure printing and offset printing. it can.
Further, the lower the melting temperature of the toner is, the more advantageous for power consumption and speeding up, but there is a problem that powder toner with a low melting temperature causes blocking. On the other hand, since liquid toner is used by being dispersed in a solvent, a toner having a low melting point (low softening point) can be employed without such a problem.

In the conventional liquid development method, the electrostatic latent image is developed by liquid development, the transfer paper is brought into contact with the surface of the photoreceptor on which the toner image is formed, and a transfer electric field is applied to the back surface of the transfer paper by a corona discharge device, a transfer roller, or the like. Form. As a result, when an electrostatic transfer method for transferring the toner image on the photoconductor onto the transfer paper is used, the charged transfer paper may be electrostatically adsorbed to the photoconductor by being charged. there were. Further, as a result of pressure applied by a transfer roller or the like, the toner image may be crushed, and it may be difficult to faithfully reproduce, for example, the width of a fine line or the dot area.
Further, in the conventional liquid development image forming apparatus, since the carrier liquid is used, the image may be crushed and a high-definition image may not be obtained. A toner image composed of a developer layer containing not only toner but also carrier liquid is formed on the surface of the latent image carrier developed by the developer composed of toner and carrier liquid. In order to transfer a toner image on a latent image carrier formed by liquid development onto a recording medium or the like with an electric field, the transfer between the latent image carrier on which the transfer electric field is formed and a transfer partner such as a recording medium is performed. That is, an appropriate amount of carrier liquid is necessary for the transfer gap.
However, if the carrier liquid is excessive, the toner image such as dots and lines may be crushed, the line width may be widened, and the image density may be uneven. The toner image formed on the latent image carrier It is difficult to faithfully transfer to a recording medium. This is because when the carrier liquid is excessively present on the surface of the latent image carrier, the electric field is insufficient at the same transfer potential difference as when the carrier liquid is small, and the toner constituting the toner image on the surface of the latent image carrier at the time of transfer is This is thought to be due to the inability to move faithfully to the latent image. In order to form a necessary electric field according to a large amount of carrier liquid, a problem that requires a higher voltage occurs.

  In addition, various types of recording media used for printing have been required. Not only plain paper, but also coated paper, resin film, etc., to apply a mud-like material called `` clay '' to the surface to give gloss or smoothness. It is expected to be used as a recording medium. Coated paper and resin films do not absorb the carrier liquid at all or absorb less than plain paper because of the surface smoothness and material characteristics. For this reason, the transfer state may occur as in the case where the carrier liquid in the transfer gap is large, and the image may be crushed.

In order to solve such a problem, some conventional liquid development image forming apparatuses include a squeeze roller that removes excess liquid carrier from the surface of the latent image carrier. The configuration including the squeeze roller includes a method of rotating the surface of the latent image carrier so that the surface moves in the opposite direction with a predetermined distance from the surface of the latent image carrier. There has been proposed a method in which a roller provided with a potential difference not to be removed is brought into contact with a toner image and a carrier liquid is adhered to remove the toner image.
Further, as a method for preventing the collapse, a roller to which a voltage is applied is opposed to the surface of the toner image on the latent image carrier with a gap so that the toner image formed on the latent image carrier is cured. There is a method of transferring the toner image to a recording medium later (for example, Patent Document 1 and Patent Document 2).
Patent Document 3 proposes a method for electrostatic transfer by supplying a non-aqueous solvent to a recording medium after transfer after drying a toner image on a latent image carrier or an intermediate transfer member. ing. By drying, the carrier liquid present between the toner particle particles forming the toner image evaporates and the toner particles aggregate, thereby increasing the interaction between the toner particles and supplying a non-aqueous solvent. Electric field transfer. When transferring to a transfer material, toner particles do not behave individually and transfer as aggregates of toner particles, so that toner images can be prevented from being crushed and spread, and high-resolution images with high resolution can be obtained. it can.

  However, even when such a method for preventing crushing is used, when electrostatic transfer is performed by the liquid development method, the toner moves from the surface of the latent image carrier to the recording medium so that the toner migrates in the liquid. Therefore, a liquid is required between the latent image carrier and the recording medium. In addition, there is a problem that the liquid is crushed or the liquid is in the paper and the paper is swollen to disturb the image.

  In view of this, there is a method described in Japanese Patent Application Laid-Open No. 2004-151620 as a method for performing transfer by a liquid developing method other than an electrostatic method. In Patent Document 4, there is a method called adhesive transfer, offset transfer, or the like in which the adhesiveness of the toner is increased by adjusting the glass transition temperature and the drying degree of the carrier liquid, and transferring with the adhesive force. When the toner image is self-fixed, a rapid film formation is performed, and the toner image that becomes a film and behaves integrally is transferred by its adhesive force. Thus, if the transfer is performed with the adhesive force of the toner, the liquid other than the toner can be eliminated as much as possible before the transfer, and the image can be transferred satisfactorily without being crushed or left behind.

No. 2990675 JP-A-9-204109 JP-A-2-272476 Special table 2001-501654 gazette

  However, even with the method described in Patent Document 4, a part of the toner image sometimes remains on the surface of the photosensitive member during transfer. This occurs because, even in a toner image formed on a film, the connection between the toner particles is weak, and a part of the toner image is peeled off from the film-like toner image and remains on the surface of the photoreceptor. When a part of the toner image remains on the surface of the photoreceptor, the image of that part is lost.

  The present invention has been made in view of the above problems, and an object of the present invention is to mainly use a toner image formed on a latent image carrier without using an electric field or using an auxiliary electric field. It is an object to provide a liquid developer for pressure-sensitive adhesive transfer that can prevent an image from being chipped at the time of transfer when used in an image forming method for transferring by the adhesive strength of the ink.

（ＲがＨの場合ｎ：６〜９、ＲがＣＨ_３の場合ｎ：１０〜１４）
・モノマーＢ

（ｎ：６〜８）
・モノマーＣ（Ｒ：Ｈ又はＣＨ_３）

・モノマーＤ（Ｒ：Ｈ又はＣＨ_３）

・モノマーＥ（Ｒ：Ｈ又はＣＨ_３）

また、請求項２の発明は、請求項１の粘着転写用液体現像剤において、上記樹脂の重量平均分子量Ｍｗが２００００〜５００００、数平均分子量Ｍｎが１００００〜４００００であることを特徴とするものである。
また、請求項３の発明は、請求項１または２の粘着転写用液体現像剤において、上記樹脂の体積抵抗が１×１０^１０〜１×１０^１６［Ω・ｃｍ］であることを特徴とするものである。 In order to achieve the above-mentioned object, the invention according to claim 1 is a method in which toner particles containing a colorant and a resin dispersed in a liquid carrier are electrostatically attached to an electrostatic latent image to make a visible image, and then a toner is formed. Monomer A and Monomer B represented by the general formulas of Chemical Formulas 6 to 10 as toner resin components constituting the toner in the liquid developer for adhesive transfer used in the electrophotographic adhesive transfer technology for transferring to the substrate with the adhesive strength of , Monomer C, monomer D, and monomer E, and the monomer component ratio of the toner resin component is monomer A / monomer B / monomer C / monomer D / monomer E = 5 to 20 [mol%] / 40 to 80 [mol%] / 5 to 40 [mol%] / 1 to 30 [mol%] / 1 to 20 [mol%] .
Monomer A (R: H or CH ₃ )

(When R is H, n is 6 to 9, and when R is CH ₃ , n is 10 to 14)
・ Monomer B

(N: 6-8)
Monomer C (R: H or CH ₃ )

Monomer D (R: H or CH ₃ )

Monomer E (R: H or CH ₃ )

The invention of claim 2 is the pressure-sensitive transfer liquid developer according to claim 1, which weight average molecular weight Mw of above SL resin 20000-50000, number average molecular weight Mn is characterized in that the 10,000 to 40,000 It is.
Further, characterized in that the invention of claim 3, claim 1 or in 2 adhesive transfer liquid developer, the volume resistivity of the resin is ^{1 × 10 10 ~1 × 10 16} [Ω · cm] It is what.

The monomer A contained in the adhesive transfer liquid developer according to any one of claims 1 to 3 imparts adhesiveness at the time of transfer, and the monomer B increases the affinity between the toner and the solvent. To improve the dispersion stability of the toner. In addition, the monomer C has an effect of promoting the film formation of the toner layer, integrating the toner layer during transfer, and strengthening the toner layer coating after fixing. As a result of intensive studies by the present inventors, a conventional liquid developer for adhesive transfer is obtained by forming a polymer in which the monomer C is hanging and graft polymerized where the monomer A and the monomer B are copolymerized. It was found that a film-like toner image can be formed in which toner image chipping is less likely to occur. However, since the monomer C cannot be directly graft-polymerized to the polymer in which the monomer A and the monomer B are copolymerized, the monomer D and the monomer E play a connecting role.
As described above, according to the first to third aspects of the invention, an image transferred with the adhesive force of the toner by including the monomer A, the monomer B, the monomer C, the monomer D, and the monomer E as the resin component of the toner. When used in the forming method, there is an excellent effect that an image can be prevented from being lost during transfer.

First, an image forming apparatus to which the adhesive transfer liquid developer according to the present invention can be applied will be described.
FIG. 1 is a schematic explanatory diagram of an example of a printer 100 which is a wet image forming apparatus using the adhesive transfer liquid developer according to the present invention as the liquid developer D.
The printer 100 includes a charging voltage applying member 2 as a charging unit, an exposure device 3 as an exposure unit, a developing roller 4 as a developing unit, and a squeeze as an excess developer removing unit around a photosensitive member 1 as a latent image carrier. A roller 5 is provided. Further, a blower 6 that applies air blow W to the surface of the photoconductor 1 is disposed downstream of the squeeze roller 5 in the surface movement direction of the photoconductor 1, and a transfer roller 7 is further disposed downstream of the squeeze roller 5. Form a nip. Further, on the downstream side of the transfer nip, a separation roller 8, a cleaning blade 9, a cleaning roller 10, a static eliminating device 11, and the like are arranged. In addition, a developer tank that stores the liquid developer D supplied to the developing roller 4 is provided.
In the printer 100, the charge is applied to the photosensitive member 1 by the charging voltage applying member 2, and the charge in the non-image portion is erased by the exposure light L from the exposure device 3. As the photoreceptor 1, a selenium photoreceptor, an organic photoreceptor, or an amorphous silicon photoreceptor can be used. The surface potential of the photoreceptor 1 during charging is in the range of 400 [V] to 1600 [V]. The exposed latent image on the photoreceptor 1 after exposure is developed with toner contained in the liquid developer D supplied from the developing roller 4 to form a toner image on the surface of the photoreceptor 1. Then, the excess developer is removed from the liquid developer D on the surface of the photoreceptor 1 after development by blowing air W from the squeeze roller 5 and the blower 6, and the transfer base material is applied by the adhesive force of the adhesive contained in the toner. Transfer to P. At the transfer position where the toner image on the photoconductor 1 is transferred to the transfer substrate P, a transfer roller 7 that contacts and opposes the photoconductor 1 is disposed, and the transfer formed by the photoconductor 1 and the transfer roller 7 is arranged. The transfer pressure at the nip is preferably 0.1 to 10 [kg / cm ² ].
The transfer substrate P that has passed through the transfer nip is separated from the photosensitive member 1 by a transfer substrate separation portion that is a portion where the separation roller 8 and the photosensitive member 1 face each other, and is conveyed outside the printer 100.
The developing roller 4 rotates in the forward direction with respect to the photosensitive member 1, the squeeze roller 5 rotates in the reverse direction, and the linear velocity relative to the photosensitive member 1 is 1.2 to 6 times that of the developing roller 4, and the linear velocity of the squeeze roller 5 is 1.2 to 4 times is effective.

The gap between the developing roller 4 and the photoreceptor 1 is preferably 50 to 250 [μm], and the gap between the squeeze roller 5 is 30 to 150 [μm].
After the developer remaining on the photosensitive member 1 without being transferred is removed by the cleaning blade 9 and the cleaning roller 10, the surface of the photosensitive member 1 is discharged by the charge removing device 11.
Further, an image can be similarly formed by a developing method in which the charge on the image portion on the photoreceptor 1 is erased and the charge on the non-image portion is left in the exposure process.

FIG. 2 is a schematic configuration diagram of a printer 100 in which an intermediate transfer member 20 is added to the printer 100 shown in FIG. A second squeeze roller 15 as a non-contact squeeze roller is disposed downstream of the contact-type squeeze roller 5 in the surface movement direction of the photosensitive member 1. Further, in the configuration shown in FIG. 2, the blower 6 is disposed so as to apply the air blow W to the intermediate transfer member 20.
The material of the intermediate transfer member 20 is preferably a solvent-resistant and elastic material such as urethane rubber, nitrile rubber, hydrin rubber, etc., and more preferably coated with a fluororesin or the like.
As shown in FIG. 2, if the printer 100 includes the intermediate transfer member 20, a material having a low surface energy can be used for the intermediate transfer member 20 that can apply a higher transfer pressure than the printer 100 of FIG. 1. There are advantages such as high solid differentiation when transferring to the intermediate transfer member 20. For this reason, it is possible to realize the printer 100 in which the adhesive transferability is improved as compared with the printer 100 of FIG. In this case, 100 to 1000 [V] electrostatic transfer is used for primary transfer from the photoreceptor 1 to the intermediate transfer member, and the primary transfer pressure is 0.1 to 3 [kg / cm ² ] and the secondary transfer pressure is 0.1 to 0.1 [kg]. 30 [kg / cm ² ] is good.

FIG. 3 is a schematic configuration diagram of the printer 100 in which the liquid developer D is developed in a thin layer on the developing roller 4 by the developer coating device 41 and is adhesively transferred. The printer 100 in FIG. 2 is different from the printer 100 in that a thin layer of the liquid developer D is formed on the developing roller 4 by the developer applying device 41 and a member for removing excess developer on the intermediate transfer member 20 is the blower 6. Instead, the difference is that a solvent removing roller 21 is arranged.
The layer thickness is preferably about 1 to 15 [μm], preferably 3 to 10 [μm]. If the layer thickness is 1 [μm] or less, the density is not sufficient, and if it is 15 [μm] or more, the resolution decreases.
By developing the electrostatic latent image after performing corona discharge on the electrostatic toner image liquid toner layer formed on the developing roller 4, the cohesive force of the toner can be improved and the resolution can be increased. The corona discharge is highly effective when the polarity is the same as that of the toner, and the voltage is preferably about 500 to 8000 [V].

The electrophotographic liquid developer D used in the printer 100 can be charged, dispersed, and kneaded by adding a colorant, a resin, and a carrier liquid to a dispersing machine such as a ball mill, a kitty mill, a disk mill, and a pin mill.
The ratio of general materials is 5 to 10 [mass%] colorant, 5 to 30 [mass%] resin, 65 to 95 [mass%] carrier liquid, and 0.1 to 1 [mass%] charge control agent. is there. This developer is used as it is or after being diluted to an appropriate ratio into the developer tank of the printer 100 for image formation.

（ＲがＨの場合 ｎ：６〜９、ＲがＣＨ_３の場合ｎ：１０〜１４）

・モノマーＢ

（ｎ：６〜８）

・モノマーＣ（Ｒ：Ｈ又はＣＨ_３）

・モノマーＤ（Ｒ：Ｈ又はＣＨ_３）

・モノマーＥ（Ｒ：Ｈ又はＣＨ_３）

Next, the adhesive transfer liquid developer, which is a feature of the present invention, will be described.
The liquid developer D used in the printer 100 is an adhesive transfer liquid developer. As a toner resin component constituting the toner, a monomer A, a monomer B, a monomer C, a monomer D, and Contains monomer E.
Monomer A (R: H or CH ₃ )

(When R is H, n: 6-9, when R is CH ₃ , n: 10-14)

・ Monomer B

(N: 6-8)

Monomer C (R: H or CH ₃ )

Monomer D (R: H or CH ₃ )

Monomer E (R: H or CH ₃ )

Examples of the monomer A include hexyl acrylate, heptyl acrylate, octyl acrylate, 2-ethylhexyl acrylate, decyl methacrylate, undecyl methacrylate, lauryl methacrylate, tridecyl methacrylate, and tetradecyl methacrylate.
Examples of the monomer B include hexyl methacrylate, heptyl methacrylate, octyl methacrylate, and 2-ethylhexyl methacrylate.
Examples of the monomer C include isobornyl acrylate and isobornyl methacrylate.
Examples of the monomer D include glycidyl acrylate and glycidyl methacrylate.
Examples of the monomer E include acrylic acid and methacrylic acid.

The monomer A imparts adhesiveness at the time of transfer, and if it is less than 5 [mol%] among the components of the synthetic resin, the adhesive force is insufficient and the adhesive transferability tends to be lowered. When the amount of monomer A is more than 20 [mol%], the film forming effect of the toner layer is hindered, and problems such as separation in the toner layer at the time of adhesive transfer and stickiness of the printed surface after fixing are likely to occur. Therefore, the monomer A is desirably 5 [mol%] to 20 [mol%] in the resin component.
Monomer B has the effect of increasing the affinity with the solvent in the toner, improving the dispersion stability of the toner, and suppressing the adhesiveness after fixing. When the monomer B is less than 40 [mol%], the effect of dispersion stability is lowered, and when it is more than 80 [mol%], the tackiness tends to be lowered and the adhesive conversion property tends to be inhibited. For this reason, the monomer B is desirably 40 [mol%] to 90 [mol%] in the resin component.
The monomer C has an effect of promoting film formation of the toner layer, integrating the toner layer during transfer, and strengthening the toner layer coating after fixing. If it is less than 5 [mol%], the filming effect is small, and transfer failure may occur or the fixing strength may be reduced. If it exceeds 40 [mol%], the affinity with the solvent decreases and aggregation occurs. There is a case.
Monomer D has an effect of grafting the resin skeleton to a crosslinked structure, increasing the strength of the toner layer film during transfer, and adsorbing and integrating with the colorant. If the amount is less than 1 [mol%], the effect is small, and if it is 30 [mol%] or more, the solvent affinity tends to decrease.
The monomer E has an effect of reacting with the monomer D to form a cross-linked structure or to improve the film-integrated transfer property of the toner layer by hydrogen bonding of carboxylic acid. If it is less than 1 [mol%], the effect is small, and if it is 20 [mol%] or more, the solvent affinity is lowered.

The resin obtained from these monomers preferably has a Tg (glass transition point) of -20 to 30 [° C]. If the temperature is lower than -20 [° C.], the image remains sticky even after fixing, and if it is higher than 30 [° C.], the adhesive transfer property decreases.
Further, the structure of the resin varies depending on the polymerization method, and examples thereof include the following compounds.

Some conventional image forming apparatuses using a liquid developer use a method of transferring non-electrostatically by heating and pressurizing as disclosed in Japanese Patent Laid-Open No. 5-11566. In this method, electric power for heating is required, and transfer unevenness may occur due to a temperature change during heating. As a transfer method for solving such a problem, there is an adhesive transfer without heating.
In the liquid developer used in the image forming apparatus that performs fixing using the adhesiveness of the toner, the toner layer exhibits adhesiveness when the carrier solvent, which is a liquid carrier, is reduced in order to realize adhesive transfer without heating. However, it is important that the toner layer is integrally transferred. Even if the toner layer is sticky, if it is divided in the toner layer, the transfer rate decreases, and the target image density cannot be obtained.
FIG. 4 is a model diagram showing a transfer state from the intermediate transfer member 20 to the transfer base P due to a difference in toner and a difference in the surface state of the transfer base P.
4 is a diagram showing a state before transfer from the intermediate transfer member 20 to the transfer substrate P. 4, A and C show the transfer to the transfer substrate P having a smooth surface, and B and D show the transfer to the transfer substrate P having an uneven surface. . 4A and 4B show a state in which the toner layer is formed and transferred to the transfer substrate P, and C and D are transferred by separating the toner layer without forming the toner layer. The state transferred to the substrate P is shown.
The adhesive transfer liquid developer is required to be capable of realizing transfer such as A and B instead of divided transfer such as C and D in FIG.

It is also important that the final fixed image does not remain sticky. For this reason, there is a need for a liquid developer that can exhibit tackiness when a certain amount of carrier solvent is removed during transfer, transfer the toner layer together, and finally form a non-sticky image. .
The liquid developer D used in the printer 100 is an electrophotographic liquid developer having good charging characteristics and adhesive transferability, and particularly good transfer regardless of the characteristics (resistance value, etc.) and surface properties (such as unevenness) of the transfer substrate. In addition, fixing is performed without development, and the carrier in the toner layer is removed by squeeze to be adhered and transferred, and the toner is pressed onto the transfer substrate P by a pressure roller (not shown) and fixed. .

Resins synthesized with acrylic monomers in electrophotographic liquid developers are well known. For example, Japanese Patent Application Laid-Open No. 06-019217 discloses a liquid developer using isobornyl (meth) acrylate, which applies the hardness of isobornyl to improve fixability.
This liquid developer is the same in that it uses the monomer A and monomer C of the present invention (isobornyl (meth) acrylate)) and is a liquid developer, but the one described in JP-A-06-019217 The difference is that isobornyl acrylate is contained in a large amount of 40 [mol%] or more as a main monomer, and that it is used for the purpose of improving scratch strength after fixing. Further, the monomers B, D and E used in the present invention are not used. The invention described in Japanese Patent Laid-Open No. 06-019217 has a configuration for the purpose of electrostatic transfer, and image distortion during transfer is a problem.

  JP-T-1999-513423 is a liquid developer for adhesive transfer using a resin having a urethane bond with an acrylic monomer and an isocyanate. Although it is a liquid developer and uses the monomer A and the monomer B used in the present invention and performs adhesive transfer in common, the invention described in JP-T-1999-513423 uses an isocyanate different from the present invention. The difference is that heat is used during transfer using the resin having the urethane bond used. Further, the monomers C, D and E of the present invention are not used. Since the invention described in JP-T-1999-513423 uses heat at the time of transfer, the heat travels to the developing section, causing a problem or avoiding it, and a large cooling device is required. And heating is required at the time of transfer, and the resin structure is also different from the present invention.

  Japanese Patent Application Laid-Open No. 2005-182036 discloses a resin synthesized from an acrylic monomer having a specified carbon number to improve the redispersibility of the toner. Although it is a liquid developer and uses the monomer A and the monomer B used in the present invention in common, the monomers C, D, and E of the present invention are not used, and an image at the time of transfer for electrostatic transfer is used. Disturbance becomes a problem.

Further, there are inventions described in Japanese Patent Application Laid-Open No. 2005-215408, Japanese Patent Application Laid-Open No. 2002-244450, and the like for adhesive transfer of dry toner. In these cases, since a thermoplastic resin is used, heat is required to melt the resin at the time of adhesive transfer. In order to perform adhesive transfer without heating, it is necessary to use a resin having a low Tg as in the present invention. However, in the case of a dry toner, since toner particles are in close contact with each other, aggregation occurs and it becomes difficult.
On the other hand, since the liquid developer for adhesive transfer of the present invention uses a thermoplastic resin having a low Tg (glass transition point) as the material, it produces adhesiveness when the solvent is reduced, and transfer without heating becomes possible.

The weight average molecular weight Mw of the toner resin of the liquid developer for adhesive transfer of the present invention is preferably 20000 to 50000, and the number average molecular weight Mn is preferably 10,000 to 40000. When Mw is less than 20,000 and Mn is less than 10000, adhesive transferability and toner cohesion during transfer are reduced, and when Mw is 50000 and Mn 40000 or more, dispersion stability is reduced.
In addition, when a part of the resin is grafted and formed into a crosslinked structure with the monomers D and E, the cohesive force of the toner layer is increased, and a good adhesive transfer property can be exhibited even if a solvent is present.
The volume resistance of the resin is desirably 1 × 10 ¹⁰ to 1 × 10 ¹⁶ [Ω · cm]. When the toner is less than 1 × 10 ¹⁰ , developability deteriorates.

The ratio between the colorant and the synthetic resin of the present invention is preferably 1/1 to 1/5. When the ratio of the synthetic resin is less than 1/1, the adhesive transferability is lowered, and when it is more than 1/5, the toner coloring power is lowered.
As the colorant, general inorganic / organic pigments and dyes can be used.
For example, Printex V, Printex U, Printex G, Special Black 15, Special Black 4, Special Black 4-B (manufactured by Degussa), Mitsubishi # 44, # 30, MR-11, MA-100 (and above) , Mitsubishi Kasei Co., Ltd.), Raven 1035, Raven 1252, News Pect II (above, Columbia Carbon Co., Ltd.), Legal 400, 660, Black Pearl 900, 1100, 1300, Mogal L (above, Cabot Corp.), etc. Pigment, phthalocyanine blue, phthalocyanine green, sky blue, rhodamine lake, malachite green lake, methyl violet lake, peacock blue lake, naphthol green B, naphthol green Y, naphthol yellow S, naphthol red, litho Le Fast Yellow 2G, Permanent Red 4R, Brilliant First Scarlet, Hansa Yellow, Benzidine Yellow, Resol Red, Lake Red C, Lake Red D, Brilliant Carmine 6B, Permanent Red F5R, Pigment Scarlet 3B Indigo, Thioindigo Oil Pink and Bold- Organic pigments such as 10B, Disperse Fast Yellow G, Disperse Blue FFR, Disperse Blue Green B, Disperse Yellow 5G, Disperse Red FB, Reactive Orange 2R, Reactive Red 3B, Reactive Blue 3G, Reactive Brilliant And dyes such as Blue R and Reactive Black B.
These colorants preferably have a high purity, and more preferably 80% or more.

Further, when it is desired to control the polarity and resistance of the colorant, flushing the colorant is also effective for controlling the chargeability of the toner particles.
In the flushing process, a resin dispersion medium is further added to a water-containing liquid in which a pigment is dissolved in water, and the mixture is mixed well in a kneader called a flasher, and water existing around the pigment is replaced by a resin dispersion medium added later. The process to do. The water taken out by this operation is discharged, the pigment is dispersed in the resin solution, dried, the solvent is removed, and the resulting mass is pulverized to obtain a colorant powder.
The ratio between the colorant and the resin during the flushing is suitably 10 to 60 parts by weight of the colorant with respect to 100 parts by weight of the resin. The flushing treatment is particularly advantageously carried out in the presence of humic acid, humic acid salts (Na salt, NH4 salt etc.) or humic acid derivatives. The amount of these humic acids added is suitably about 0.1 to 30% by weight of the colorant-containing liquid.
The resin used in the flushing treatment is preferably a polyester resin, an epoxy resin, a polyolefin resin, or the like.

As the carrier liquid used in the liquid developer of the present invention, a high resistance and low dielectric constant is preferable, and isoparaffin hydrocarbon, liquid paraffin, polyalphaolefin, silicone oil and the like are preferable. Isoparaffin hydrocarbons are Isopar C, Isopar E, Isopar G, Isopar H, Isopar L, Isopar M, Isopar V, Solvesso 100, Solvesso 150, Solvesso 200, Exor 100/140, Exor D30, Exor D40, Exor D80, Exorol D110, Exor D130 (exxon Mobil) are liquid paraffins such as Christol J52, J72, J102, J142, J172, J202 (exclusive, Esso Petroleum), and polyalphaolefins are Syn2, Syn4. Syn6 (Exxon Mobil Co., Ltd.) and other silicone-based oils include KF96 1-1000 cst (Shin-Etsu Silicone), SH200, SH344 (Toray Silicone), TSF45. 1 (Toshiba Silicone).
The boiling point of the carrier liquid is preferably 100 [° C.] or higher. If the boiling point is 100 [° C.] or less, the solvent is likely to volatilize, so that the amount of the solvent in the toner layer becomes too small before transfer, making it difficult to develop tackiness, and untransferred toner is likely to stick, and is easy to clean. There may be problems.

The ζ potential of the toner is preferably 10 to 200 [mV]. When the ζ potential is lower than 10 [mV], the toner particles aggregate, electrophoretic properties are deteriorated and the background is soiled, and the density is lowered. On the other hand, if the ζ potential is higher than 200 [mV], the adhesion amount of the photosensitive member may decrease and the density may decrease.
The average particle size is preferably 0.1 to 3 [μm]. If the average particle size is 0.1 [μm] or less, a sufficient concentration may not be obtained or blemishes may occur easily, and if 5 [μm] or more, Color and resolution may deteriorate.
The liquid developer of the present invention exhibits adhesiveness by increasing the solid content in the developing process and the liquid removing process, and enables adhesive transfer. After the adhesive transfer and fixing to the substrate, the solvent disappears, so the adhesiveness is lost.

Next, specific examples of the toner resin component constituting the toner contained in the adhesive transfer liquid developer of the present invention will be shown.
[Resin synthesis example 1]
Isopar H300 [g] was charged into a 0.5 [L] flask equipped with a stirrer, a thermometer, a condenser, and a dropping funnel, heated to 90 [° C.], and stirred with lauryl methacrylate (monomer A) 0. 02 [mol], 2-ethylhexyl methacrylate (monomer B) 0.25 [mol], glycidyl methacrylate (monomer D) 0.04 [mol], methacrylic acid (monomer E) 0.01 [mol], benzoyl peroxide A monomer solution consisting of 1 g of the catalyst was added dropwise over 2 hours.
After the dropping, the polymerization was carried out for 5 hours while maintaining the temperature at 95 [° C].
Thereafter, a monomer solution consisting of 0.09 [mol] of isobornyl methacrylate (monomer C) and 0.5 [g] of azbisisobutyronitrile was added dropwise over 1 hour, and the polymerization was carried out for 1 hour while maintaining at 85 [° C]. Went.
The polymerization rate of the synthesized resin was 97 [%], the molecular weight Mn was 21000, and Mw was 39000.

[Resin synthesis example 2]
A 0.5 [L] flask equipped with a stirrer, thermometer, condenser, and dropping funnel was charged with Crystol J72 320 [g], heated to 105 [° C.] and stirred with tridecyl methacrylate (monomer A ) 0.07 [mol], heptyl methacrylate (monomer B) 0.20 [mol], isobornyl acrylate (monomer C) 0.09 [mol], glycidyl methacrylate (monomer D) 0.06 [mol] A monomer solution consisting of 0.06 [mol] methacrylic acid (monomer E) and 1 [g] benzoyl peroxide was added dropwise over 3 hours. After the dropwise addition, polymerization was carried out for 5 hours while maintaining the temperature at 100 [° C].
The polymerization rate of the synthesized resin was 99 [%], the molecular weight Mn was 12000, and Mw was 21000.

[Resin synthesis example 3]
A 0.5 [L] flask equipped with a stirrer, thermometer, condenser, and dropping funnel was charged with Exol D130 270 [g], heated to 80 [° C.], and stirred with 2-ethylhexyl acrylate (monomer A) 0 .05 [mol], hexyl methacrylate (monomer B) 0.30 [mol], isobornyl acrylate (monomer C) 0.04 [mol], glycidyl acrylate (monomer D) 0.04 [mol], methacrylic acid (Monomer E) A monomer solution consisting of 0.02 [mol] and benzoyl peroxide 0.5 [g] was added dropwise over 3 hours. After the dropping, the polymerization was carried out for 5 hours while maintaining at 85 [° C.].
The polymerization rate of the synthesized resin was 99 [%], the molecular weight Mn was 33000, and Mw was 48,000.

[Resin Synthesis Example 4]
350 g of isododecane was charged into a 0.5 [L] flask equipped with a stirrer, a thermometer, a condenser, and a dropping funnel, heated to 85 [° C.], and stirred with tetradecyl methacrylate (monomer A) 0.03 [ mol], 2-ethylhexyl methacrylate (monomer B) 0.31 [mol], glycidyl methacrylate (monomer D) 0.01 [mol], methacrylic acid (monomer E) 0.01 [mol], benzoyl peroxide 1 The monomer solution consisting of [g] was added dropwise over 2 hours.
After the dropping, the polymerization was carried out for 5 hours while maintaining at 85 [° C.].
Thereafter, a monomer solution consisting of 0.04 [mol] of isobornyl methacrylate (monomer C) and 0.3 [g] of azbisisobutyronitrile was added dropwise over 1 hour, and kept at 80 [° C.] for 2 hours of polymerization. Went.
The polymerization rate of the synthesized resin was 98 [%], the molecular weight Mn was 28000, and Mw was 44,000.

[Resin Synthesis Example 5]
Isopar M350 [g] was charged into a 0.5 [L] flask equipped with a stirrer, a thermometer, a condenser, and a dropping funnel, heated to 85 [° C.], and stirred with decyl methacrylate (monomer A) 0. 05 [mol], 2-ethylhexyl methacrylate (monomer B) 0.20 [mol], glycidyl methacrylate (monomer D) 0.05 [mol], methacrylic acid (monomer E) 0.10 [mol], benzoyl peroxide A monomer solution consisting of 1 g of the catalyst was added dropwise over 2 hours.
After the dropping, the polymerization was carried out for 5 hours while maintaining at 85 [° C.].
Thereafter, a monomer solution composed of 0.04 [mol] of isobornyl methacrylate (monomer C) and 0.4 [g] of azbisisobutyronitrile was dropped over 1 hour, and the polymerization was continued for 2 hours while maintaining at 80 [° C.]. Went.
The polymerization rate of the synthesized resin was 97 [%], the molecular weight Mn was 31000, and Mw was 46000.

[Resin Synthesis Example 6]
Isopar H 270 [g] was charged into a 0.5 [L] flask equipped with a stirrer, thermometer, condenser, and dropping funnel, heated to 80 [° C.], and stirred with 2-ethylhexyl acrylate (monomer A) 0 .10 [mol], hexyl methacrylate (monomer B) 0.10 [mol], isobornyl acrylate 0.04 (monomer C) [mol], glycidyl acrylate (monomer D) 0.04 [mol], methacrylic acid (Monomer E) A monomer solution consisting of 0.02 [mol] and benzoyl peroxide 0.5 [g] was added dropwise over 3 hours. After the dropping, the polymerization was carried out for 5 hours while maintaining at 85 [° C.].
The polymerization rate of the synthesized resin was 96 [%], the molecular weight Mn was 34000, and Mw was 49000.

[Resin Synthesis Example 7]
Isopar H 290 [g] was charged into a 0.5 [L] flask equipped with a stirrer, thermometer, condenser, and dropping funnel, heated to 85 [° C.], and stirred with lauryl methacrylate (monomer A) 0 .01 [mol], hexyl methacrylate (monomer B) 0.35 [mol], isobornyl acrylate (monomer C) 0.02 [mol], glycidyl acrylate (monomer D) 0.03 [mol], methacrylic acid (Monomer E) A monomer solution consisting of 0.02 [mol] and benzoyl peroxide 0.5 [g] was added dropwise over 3 hours. After the dropping, the polymerization was carried out for 5 hours while maintaining at 85 [° C.].
The polymerization rate of the synthesized resin was 95 [%], the molecular weight Mn was 30000, and Mw was 47000.

Next, specific examples of the toner resin component of the comparative example compared with the toner of the liquid developer for pressure-sensitive adhesive transfer of the present invention will be shown. In addition, what is described as "not applicable" among the monomers which comprise a comparative example is a monomer which does not correspond to any of the said monomers AE.
[Resin synthesis comparative example 1]
Isopar L320 [g] was charged into a 0.5 [L] flask equipped with a stirrer, a thermometer, a condenser, and a dropping funnel, heated to 105 [° C.] and stirred with stearyl methacrylate (not applicable). 10 [mol], octyl methacrylate (monomer B) 0.20 [mol], methyl methacrylate (not applicable) 0.15 [mol], glycidyl methacrylate (monomer D) 0.03 [mol], methacrylic acid ( Monomer E) A monomer solution consisting of 0.02 [mol] and benzoyl peroxide 1 [g] was added dropwise over 3 hours. After the dropwise addition, polymerization was carried out for 5 hours while maintaining the temperature at 100 [° C].
The polymerization rate of the synthesized resin was 97 [%], the molecular weight Mn was 15000, and Mw was 27000.

[Resin synthesis comparative example 2]
Isopar H 290 [g] was charged into a 0.5 L flask equipped with a stirrer, thermometer, condenser, and dropping funnel, heated to 85 [° C.], and stirred with stirring, 2-ethylhexyl methacrylate (monomer B) 0.35 [Mol], styrene (not applicable) 0.02 [mol], glycidyl acrylate (monomer D) 0.03 [mol], methacrylic acid (monomer E) 0.02 [mol], benzoyl peroxide 0.5 [mol] g] was added dropwise over 3 hours. After the dropping, the polymerization was carried out for 5 hours while maintaining at 85 [° C.].
The polymerization rate of the synthesized resin was 95 [%], the molecular weight Mn was 31000, and Mw was 48,000.

[Resin synthesis comparative example 3]
Isopar H 290 [g] was charged into a 0.5 [L] flask equipped with a stirrer, thermometer, condenser, and dropping funnel, heated to 85 [° C.], and stirred with butyl methacrylate (not applicable) 0 .36 [mol], benzyl acrylate (not applicable) 0.05 [mol], glycidyl acrylate (monomer D) 0.04 [mol], methacrylic acid (monomer E) 0.03 [mol], benzoyl peroxide 0 A monomer solution consisting of 0.5 [g] was added dropwise over 3 hours. After the dropping, the polymerization was carried out for 5 hours while maintaining at 85 [° C.].
The polymerization rate of the synthesized resin was 96 [%], the molecular weight Mn was 20000, and Mw was 37000.

Next, Examples 1 to 5 and Reference Configuration Examples 1 to 3 in which image formation was performed using the above resin synthesis examples 1 to 7, and Comparative Examples in which image formation was performed using the above resin synthesis comparison examples 1 to 3 Experiments for comparing each measured value were performed for 1 to 3. The conditions of Examples 1 to 5, Reference Configuration Examples 1 to 3 and Comparative Examples 1 to 3 are shown below.

[Example 1]
Phthalocyanine blue (PB-15: 3) (manufactured by Dainichi Seika Co., Ltd.) 14 parts Resin of the above resin synthesis example 1 (solid content 20.7 [%]) 203 parts Isopar H (made by ExxonMobil) 30 parts Charge control agent (Phosphatidylcholine) (manufactured by Sakai Oil Co., Ltd.) 3 parts These were placed in a ball mill and dispersed for 72 hours, and further 30 parts of Isopar H was added and dispersed for 1 hour to obtain a concentrated liquid developer.
An image was formed with the apparatus shown in FIG. 1 using a developer obtained by mixing the concentrated liquid developer toner 100 [g] and Isopar H1 [L].
Adhesive transfer was performed on plain paper (Ricoh PPC paper type 6000 <70 W>) with a transfer developer solid content of 92 [%] and a transfer pressure of 2 [kg / cm ² ].

[Example 2]
The same procedure as in Example 1 was performed except that image formation and adhesive transfer were performed with the apparatus of FIG.
Primary transfer was performed by electrostatic transfer at an applied voltage of 200 [V], and secondary transfer was performed by adhesive transfer at a transfer pressure of 8 [kg / cm ² ]. The developer solid content at the time of secondary transfer was 97 [%].

Example 3
Quinacridone Red (PR-122) (Fuji Dye Co.) / Polyester resin (Mitsubishi Rayon Co., Ltd.) Flushing kneaded product (ratio 1/1) 30 parts Resin of the above resin synthesis example 2 (solid content 22.1 [%]) 68 parts Cristol J72 (manufactured by Esso Petroleum) 50 parts Charge control agent (zirconium naphthenate) (manufactured by Nippon Chemical Industry Co., Ltd.) 2 parts These were placed in a ball mill and dispersed for 90 hours. This was dispersed for 1 hour to obtain a concentrated liquid developer.
The concentrated liquid developer was developed in a thin layer with the apparatus shown in FIG. 3 to form an image.
The primary transfer was electrostatic transfer at an applied voltage of 300 [V], and the secondary transfer was adhesive transfer to a Ricoh OHP sheet at a transfer pressure of 5 [kg / cm ² ]. The developer solid content at the time of secondary transfer was 80 [%].

Example 4
Disperse Blue 60 (DB-60) (Arimoto Chemical Co., Ltd.) 15 parts Resin of the above resin synthesis example 3 (solid content 23.8 [%]) 126 parts Exol D130 (manufactured by ExxonMobil) 40 parts Charge control agent (Cobalt naphthenate) (manufactured by Nippon Kagaku Sangyo Co., Ltd.) 3 parts These were placed in a basket mill and dispersed for 5 hours, and then 40 parts of Exol D130 was added and dispersed for 1 hour to obtain a concentrated liquid developer.
Image formation was performed with the apparatus shown in FIG. 2 using a developer obtained by mixing 200 [g] of the concentrated liquid developer toner and Exol D130 1 [L].
The primary transfer was performed by electrostatic transfer with an applied voltage of 300 [V], and the secondary transfer was performed by adhesive transfer to polyester satin at a transfer pressure of 10 [kg / cm ² ]. The developer solid content during the secondary transfer was 96 [%].

Example 5
Naphthol red (PR-184) (manufactured by Clariant) 18 parts Resin of the above resin synthesis example 4 (solid content 20.7 [%]) 435 parts Isododecane (manufactured by ExxonMobil) 60 parts Charge control agent (zirconium naphthenate) (Nippon Chemical Industry Co., Ltd.) 2 parts These were placed in a ball mill and dispersed for 96 hours, and then 70 parts of isododecane was added and dispersed for 1 hour to obtain a concentrated liquid developer.
The concentrated liquid developer was developed in a thin layer with the apparatus shown in FIG. 3 to form an image.
The primary transfer was electrostatic transfer at an applied voltage of 300 [V], and the secondary transfer was adhesive transfer to a brass plate having a thickness of 0.5 [mm] at a transfer pressure of 8 [kg / cm ² ]. The developer solid content during the secondary transfer was 95 [%].

[ Reference configuration example 1 ]
Naphthol Red (PR-184) (Clariant) / Epoxy Resin (Japan Epoxy Resin)
Flushing kneaded product (ratio 1/1) 34 parts Resin of resin synthesis example 5 (solid content 19.4 [%]) 263 parts Isopar M (manufactured by ExxonMobil) 45 parts Charge control agent (zirconium naphthenate) (Nippon Kagaku) (Manufactured by Sangyo Co., Ltd.) 2 parts These were placed in a ball mill and dispersed for 90 hours, and then 50 parts of Isopar M was further added and dispersed for 1 hour to obtain a concentrated liquid developer.
The concentrated liquid developer was developed in a thin layer with the apparatus shown in FIG. 3 to form an image.
The primary transfer was electrostatic transfer at an applied voltage of 300 [V], and the secondary transfer was adhesive transfer to high-coated paper at a transfer pressure of 6 [kg / cm ² ]. The developer solid content during the secondary transfer was 96 [%].

[ Reference configuration example 2 ]
Quinacridone red (PR-122) (manufactured by Fuji Pigment) / polyester resin (manufactured by Mitsubishi Rayon Co., Ltd.) 30 parts of flashing kneaded material (ratio 1/1) 76 parts Cristol J72 (manufactured by Esso Petroleum Corporation) 55 parts Charge control agent (zirconium naphthenate) (manufactured by Nippon Chemical Industry Co., Ltd.) 2 parts These were placed in a ball mill and dispersed for 90 hours. This was dispersed for 1 hour to obtain a concentrated liquid developer.
The concentrated liquid developer was developed in a thin layer with the apparatus shown in FIG. 3 to form an image.
The primary transfer was electrostatic transfer at an applied voltage of 300 [V], and the secondary transfer was adhesive transfer to a Ricoh OHP sheet at a transfer pressure of 5 [kg / cm ² ]. The developer solid content at the time of secondary transfer was 78 [%].

[ Reference Configuration Example 3 ]
Disperse Blue 60 (DB-60) (Arimoto Chemical Co., Ltd.) 15 parts Resin of the above resin synthesis example 7 (solid content 21.2 [%]) 142 parts Exol D130 (made by ExxonMobil) 40 parts Charge control agent (Cobalt naphthenate) (manufactured by Nippon Kagaku Sangyo Co., Ltd.) 3 parts These were placed in a basket mill and dispersed for 5 hours, and then 40 parts of Exol D130 was further added and dispersed for 1 hour to obtain a concentrated liquid developer.
Image formation was performed with the apparatus shown in FIG. 2 using a developer obtained by mixing 200 [g] of the concentrated liquid developer toner and Exol D130 1 [L].
The primary transfer was performed by electrostatic transfer with an applied voltage of 300 [V], and the secondary transfer was performed by adhesive transfer to polyester satin at a transfer pressure of 10 [kg / cm ² ]. The developer solid content at the time of secondary transfer was 94 [%].

[Comparative Example 1]
Phthalocyanine blue (PB-15: 3) (manufactured by Dainichi Seika Co., Ltd.) 14 parts Resin of resin synthesis comparative example 1 (solid content 22.1 [%]) 190 parts Isopar H (manufactured by ExxonMobil) 30 parts Charge control agent (Phosphatidylcholine) (manufactured by Sakai Oil Co., Ltd.) 3 parts These were placed in a ball mill and dispersed for 72 hours. Further, 30 parts of Isopar H was added and dispersed for 1 hour to obtain a concentrated liquid developer.
An image was formed with the apparatus shown in FIG. 1 using a developer obtained by mixing the concentrated liquid developer toner 100 [g] and Isopar H1 [L].
Adhesive transfer was performed on plain paper (Ricoh PPC paper type 6000 <70 W>) at a transfer developer solid content of 90% and a transfer pressure of 2 kg / cm ² .

[Comparative Example 2]
Disperse Blue 60 (DB-60) (manufactured by Arimoto Chemical Co., Ltd.) 15 parts Resin of resin synthesis comparative example 2 (solid content 25.6 [%]) 117 parts Exol D130 (manufactured by ExxonMobil) 40 parts Charge control agent (Cobalt naphthenate) (manufactured by Nippon Kagaku Sangyo Co., Ltd.) 3 parts These were placed in a basket mill and dispersed for 5 hours, and then 40 parts of Exol D130 was added and dispersed for 1 hour to obtain a concentrated liquid developer.
Image formation was performed with the apparatus shown in FIG. 2 using a developer obtained by mixing 200 [g] of the concentrated liquid developer toner and Exol D130 1 [L].
The primary transfer was performed by electrostatic transfer with an applied voltage of 300 [V], and the secondary transfer was performed by adhesive transfer to polyester satin at a transfer pressure of 10 [kg / cm ² ]. The developer solid content during the secondary transfer was 92 [%].

[Comparative Example 3]
Disperse Blue 60 (DB-60) (Arimoto Chemical Co., Ltd.) 15 parts Resin Synthesis Comparative Example 3 resin (solid content 26.6 [%]) 113 parts Exol D130 (ExxonMobil Corporation) 40 parts Charge control agent (Cobalt naphthenate) (manufactured by Nippon Kagaku Sangyo Co., Ltd.) 3 parts These were placed in a basket mill and dispersed for 5 hours, and then 40 parts of Exol D130 was added and dispersed for 1 hour to obtain a concentrated liquid developer.
Image formation was performed with the apparatus shown in FIG. 2 using a developer obtained by mixing 200 [g] of the concentrated liquid developer toner and Exol D130 1 [L].
The primary transfer was performed by electrostatic transfer with an applied voltage of 300 [V], and the secondary transfer was performed by adhesive transfer to polyester satin at a transfer pressure of 10 [kg / cm ² ]. The developer solid content during the secondary transfer was 93 [%].

Image density is measured by X-Rite.
The average particle size is based on Shimadzu SA-CP3.
The liquid developer is diluted with Isopar until the transmittance reaches about 15% with an integrating sphere turbidimeter, and filled in a cell for SA-CP3. The measurement conditions were ACCEL480, MODE: CENT, 3-16 channels.
The ζ potential is based on Otsuka Electronics ELS-8000.
Cell: Low dielectric constant cell, electric field: 500 [V / cm], measured 6 times in average mode.
The transfer rate was calculated from the concentration by the tape peeling method, and was determined by the following formula.
Transfer rate = (Concentration on photoconductor before transfer−Remaining photoconductor density after transfer) / (Concentration on photoconductor before transfer) × 100 [%]
The charge control rate was calculated by the electrodeposition method, and obtained under the following conditions.
The distance between electrodes was 1 [cm], the electrode area was 2 [cm] × 2 [cm], and the electrodeposition time was 100 [seconds].

Table 1 shows the measurement results of Examples 1 to 5, Reference Configuration Examples 1 to 3 and Comparative Examples 1 to 3.

As shown in Table 1, the combination of the adhesive transfer method using the printer 100 shown in FIG. 1 to FIG. 3 and the liquid developer enables printing with high image density with good charge control and non-heated adhesive transfer. It became.
As shown in FIGS. 4A and 4B, the material (resistance value, etc.) of the transfer substrate P is not restricted, and the toner layer is transferred as a unit. Therefore, good transfer can be performed even on uneven substrates. did it.
In Example 1, since the liquid developer of the present invention is used, adhesive transferability is good. However, transferability is lower than that in Example 2 because of direct transfer from the photoreceptor. As can be seen from the results of Example 2, it is considered that the intermediate transfer member has lower surface energy than the photosensitive member, the toner layer has good releasability, and pressure is applied during transfer.
In Reference Configuration Example 1, since the ratio of the monomer E was high, the toner charging rate was slightly decreased.
In Reference Configuration Example 2, since the ratio of the monomer A was high, it was partially separated in the toner layer, so the transfer rate was slightly reduced. Further, the image surface after fixing was slightly sticky.
In Reference Configuration Example 3, since the monomer A was low and the ratio of the monomer B was high, the adhesiveness during transfer was weak and the transferability was slightly lowered.

In Comparative Example 1, since the material of the present invention was not used, no tackiness was exhibited, toner characteristics non-heat-adhesive transfer could not be performed, and toner characteristics were not good.
In Comparative Example 2, since the monomer A component of the present invention was not present, the adhesiveness was not exhibited and the adhesive transfer was not performed. Further, since there was no monomer C component, the film was not formed into a film and split in the toner layer, and the resin developability was poor because the resin resistance was low.
In Comparative Example 3, the solvent affinity of the synthetic resin was low, the toner particle size was large due to aggregation, the developability was poor, the transfer layer was soft, and the image after fixing was sticky.

  As described above, in the case of the adhesive transfer liquid developer used in the printer 100 of the present embodiment, the toner adhesion is achieved by including the monomer A, the monomer B, the monomer C, the monomer D, and the monomer E as the resin component of the toner. When used in an image forming method that transfers by force, there is an excellent effect that an image can be prevented from being lost during transfer. In addition, since the images can be integrated and transferred by the adhesive force, a high-definition image can be formed on a low-resistance substrate or a substrate with unevenness.

Further, the monomer component ratio of the toner resin component is monomer A / monomer B / monomer C / monomer D / monomer E = 5 to 20 [mol%] / 40 to 80 [mol%] / 5 to 40 [mol%] / The relationship of 1-30 [mol%] / 1-20 [mol%] is satisfied.
When the ratio of the monomer A is in the range of 5 to 20 [mol%], there are problems such as inhibition of the effect of forming a toner film due to too much monomer A and stickiness after fixing, and too few. It is possible to prevent the occurrence of a problem that the adhesive transferability is deteriorated due to insufficient adhesive force.
When the ratio of the monomer B is in the range of 40 to 80 [mol%], the effect of dispersion stability caused by the amount of the monomer B being too small and the adhesiveness caused by the amount of the monomer B being too low are reduced. Thus, it is possible to prevent problems such as inhibiting adhesive transferability. Then, the affinity between the toner and the solvent can be increased, and the dispersion stability of the toner in the liquid developer can be improved.
When the ratio of the monomer C is in the range of 5 to 40 [mol%], there are defects such as transfer failure due to a decrease in filming effect due to too little monomer C and a decrease in fixing strength, and the monomer The problem that the affinity with the solvent due to too much C is reduced and aggregation occurs can be prevented. Further, it is possible to promote film formation of the toner layer, to transfer the toner layer integrally during transfer, and to strengthen the toner layer coating after fixing.
When the ratio of the monomer D is in the range of 1 to 30 [mol%], the resin skeleton can be grafted and crosslinked to increase the strength of the toner layer film at the time of transfer, and is adsorbed and integrated with the colorant. I can do it.
When the ratio of the monomer E is in the range of 1 to 20 [mol%], it acts on the formation of a crosslinked structure by reaction with the monomer D, and is effective in the film integration transfer property of the toner layer due to the hydrogen bond of the carboxylic acid. is there.

  Further, since the weight average molecular weight Mw of the resin of the toner resin is 20000 to 50000 and the number average molecular weight Mn is 10,000 to 40,000, good adhesive transferability, toner cohesive force during transfer, and good dispersion stability are obtained. Can be realized.

Further, if the toner resin has a volume resistance of less than 1 × 10 ¹⁰ [Ω · cm], developability may be reduced when the toner is used, and the volume resistance is larger than 1 × 10 ¹⁶ [Ω · cm]. In this case, the polarity controllability is lowered. When the volume resistance of the toner resin contained in the liquid developer D is 1 × 10 ¹⁰ to 1 × 10 ¹⁶ [Ω · cm], developability and polarity controllability when the toner is used can be maintained.

1 is a schematic explanatory diagram of a wet image forming apparatus according to an embodiment. FIG. 3 is a schematic explanatory diagram of a second configuration of the wet image forming apparatus according to the embodiment. FIG. 3 is a schematic explanatory diagram of a third configuration of the wet image forming apparatus according to the embodiment. The model figure which shows the transfer state from an intermediate transfer member to a transfer base material.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Photoconductor 2 Charging voltage provision member 3 Exposure apparatus 4 Developing roller 5 Squeeze roller 6 Blower 7 Transfer roller 8 Separation roller 9 Cleaning roller 10 Cleaning roller 11 Static elimination device 15 Second squeeze roller 20 Intermediate transfer member 21 Solvent removal roller 100 Printer

Claims (3)

An electrophotographic adhesive transfer technology in which toner particles containing a colorant and a resin dispersed in a liquid carrier are electrostatically attached to an electrostatic latent image, visualized, and then transferred to a substrate by the adhesive force of the toner. In the liquid developer for adhesive transfer used in
As a toner resin component constituting the toner, the monomer A, the monomer B, the monomer C, the monomer D, and the monomer E represented by the general formulas 1 to 5 are included .
The monomer component ratio of the toner resin component is monomer A / monomer B / monomer C / monomer D / monomer E = 5 to 20 [mol%] / 40 to 80 [mol%] / 5 to 40 [mol%] / 1. A liquid developer for adhesive transfer, characterized in that it is ˜30 [mol%] / 1 to 20 [mol%] .
Monomer A (R: H or CH ₃ )

(When R is H, n: 6-9, when R is CH ₃ , n: 10-14)

・ Monomer B

(N: 6-8)

Monomer C (R: H or CH ₃ )

Monomer D (R: H or CH ₃ )

Monomer E (R: H or CH ₃ )

The adhesive transfer liquid developer 請 Motomeko 1,
A liquid developer for pressure-sensitive adhesive transfer, wherein the resin has a weight average molecular weight Mw of 20,000 to 50,000 and a number average molecular weight Mn of 10,000 to 40,000. In claim 1 or 2 of the pressure-sensitive transfer liquid developer,
A liquid developer for pressure-sensitive adhesive transfer, wherein the volume resistance of the resin is 1 × 10 ¹⁰ to 1 × 10 ¹⁶ [Ω · cm].

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