JP3531766B2 - Ink composition and novel recording method - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to electrophotography, electrostatic printing,
The present invention relates to an ink composition used for electrostatic recording or printing ink, inkjet ink, paint, etc., a method for producing the same, and a process for using the same, and
The present invention relates to a recording method characterized by causing charged ink to fly to a charged substrate, and an ink composition thereof.

[0002]

2. Description of the Related Art In general, an ink jet recording system is one in which a liquid or solid ink is ejected from a nozzle, a slit, a porous film or the like, and the ink is attached to paper, cloth, film or the like for recording. Inkjet recording type printers are used everywhere because of their advantages such as low noise during use, small size, and low cost. Further, further studies of printers have been vigorously carried out, and in particular, black monochromatic printers, which can obtain good print quality on so-called plain paper such as report paper and copy paper, have been put on the market.

As an example of the wet toner jet recording system, a printing system (PCT / PCT / PCT / PCT / PCT) is used in which a voltage having the same polarity as that of the toner particles is applied to the tip of the line head to form an aggregate of the toner particles. AU92-006
65) or a printing method having means for causing the wet toner on the surface of the developing roller to fly to the latent image potential of the photosensitive member, which is closely arranged with a developing gap between the developing roller and the electrophotographic photosensitive member (JP-A-6-137791). Japanese Patent Application No. 5-301
No. 900 specification) has been proposed. U.S. Pat. No. 3.060.429 describes an electrostatic inkjet printing method in which a developer is electrostatically sucked. This method preferably has two pairs of opening / closing electrodes for blocking or controlling the jet flow of ink droplets and electrode pairs for adjusting the ink droplet flight path, and the step of generating charged development droplets, the nozzle and A step of accelerating the developing liquid droplets toward a plate electrode from a nozzle containing a developing solution while applying a high voltage between the plate electrode and the plate electrode immediately before the ink droplets reach the plate electrode. Supplying ink drops onto the paper provided in front of the strip electrodes.

Regarding the ink used in the ink jet printer, (1) it is possible to obtain a uniform image with high resolution and high density without bleeding or fog on the paper; (2)
No clogging due to ink drying at the nozzle tip, ejection response and ejection stability are always good, (3) ink drying property on paper is good, and (4) image fastness is good. , (5) Good long-term storage stability,
Is required.

In order to satisfy these requirements, many studies have been made on ink jet recording inks, various additives have been studied, and various water-soluble organic solvents have been studied. It has been conventionally proposed to use a surfactant (Japanese Patent Publication No. 62-11781) and a block copolymer of ethylene oxide and propylene oxide (Japanese Patent Laid-Open No. 25789/1989). . In addition, in a wet toner used in an inkjet recording system, isoparaffin is mainly used as a dispersion medium, carbon black, an organic pigment, etc. are used as a colorant.

Further, conventionally, electrophotographic developers have generally been kneaded with a colorant, a resin, a polarity control agent and the like, and pulverized to 5-1.
A dry electrophotographic developer having powder particles of 0 μm was prepared. Further, as the electrophotographic liquid developer using a non-aqueous solvent, generally, a non-aqueous resin dispersion liquid and a colorant are dispersed and mixed to have a particle diameter of 0.5 to 2 μm. In these comparisons, the latter liquid developer gives a clearer image.

By the way, a non-aqueous resin dispersion liquid is used for preparing a liquid developer, and this non-aqueous resin dispersion liquid (hereinafter referred to as NAD) stably disperses a colorant such as a pigment in a solvent. It is used for the purpose, and generally an amphipathic resin is used. This amphiphilic resin is derived from a vinyl polymer, and a graft polymer is mainly used. However, when a graft polymer is produced, a relatively large amount of by-produced non-aqueous solvent-soluble non-grafted polymer or insoluble polymer deteriorates dispersibility in a colorant, so that long-term storage There was a problem that sedimentation occurred.

Various proposals have been made so far for a non-aqueous resin dispersion liquid used in a liquid developer for electrostatic latent image development, a paint, etc. and a method for producing the same. For example, a liquid developer for electrophotography described in Japanese Patent Publication No. 62-3859 proposes a resin obtained by reacting a natural resin-modified thermosetting resin in a long chain alkyl group-containing monomer as a resin for forming toner particles. Has been done.

However, although these non-aqueous resin dispersions are effective in improving the dispersion stability of the colorant, they are not yet NAD having sufficient dispersion stability. Japanese Patent Publication No. 56-10619 discloses a polymer of liquid toner. This is 0.4 to 0.8 in a non-aqueous solvent.
A liquid toner obtained by synthesizing a white latex of μm and then dyeing the white latex with a dye such as Victoria blue. In this case, it is difficult to form a black toner, and since it is a dye type, there are drawbacks such as low image density and photobleaching.

[0010]

In summary, in the conventionally proposed ink jet recording ink, the above-mentioned 5
Nothing has yet been obtained that satisfies all of the point requirements. On the other hand, some ink jet recording type printers capable of obtaining a full color image are commercially available, but when these are printed on plain paper, the drying property is poor and the high speed output of the printer is hindered. Ink is disturbed and mixed, and faithful image reproduction cannot be obtained. Therefore, it is usually necessary to use surface-treated special dedicated paper, which increases the cost of printing per sheet and makes it difficult to spread as a general-purpose printer. Further, in the wet toner jet method in which an organic solvent is used as ink, a high voltage is required to eject or fly the wet toner from the ejection head or the surface of the developing roller. Further, the printed matter had poor fixability on paper and the image density was low. Also, high resolution was difficult to obtain.

The object of the present invention is to remedy the above-mentioned drawbacks in the prior art, and to fly at low applied voltage to paper, plastic,
An object of the present invention is to provide an ink composition for inkjet recording, which has excellent fixability on a substrate such as a metal and can print with high image density, high contrast and high resolution. Another object of the present invention is to provide a novel ink jet recording method using the above ink composition.

A further object of the present invention is to provide an electrophotographic developer having excellent fixability of copy and capable of low temperature fixing, indirect fixing such as warm air, and a copying method using this developer. Still another object of the present invention is to provide an electrophotographic developer for color copying which can obtain a copy with high color reproducibility on OHP, and a copying method using the developer.
Still another object of the present invention is to provide an electrophotographic developer that does not suffer from the disadvantages of fading and low image density.

[0013]

The present inventor has studied various aspects of an ink jet recording ink and an ink jet recording method suitable for the ink, and as a result, charged particles containing at least a dispersion liquid and a coloring agent. The specific resistance and charge amount of the ink containing as a main component are related to the flight characteristics in the ink jet recording method or the wet toner jet recording method, that is, the larger the specific charge amount and the specific resistance of the ink, the smaller the dot diameter is printed. I confirmed that It was also confirmed that it has excellent fixability on paper.

The specific charge amount of the ink (charged particles) of the present invention is 10 to 1000 μc / g, preferably 100 to 800 μm.
It is c / g. When the specific charge amount of the ink is 10 μc / g or less, the flying dot diameter of the ink is large, the printing dot diameter is large, and it is difficult to improve the resolution. Further, the fixability is lowered. In addition, the image density decreases with ink having a specific charge amount of 1000 μc / g or more. With respect to the ejectability of ink, the ink having a higher specific charge amount has a lower ejection applied voltage, and the ink having a lower specific charge amount tends to have a higher ejection applied voltage.

Most of the conventional liquid developers for electrophotography have a specific charge amount of 10 μc / g or less and a specific resistance of 10 ¹⁰ Ωcm or less. In the case of the electrophotographic method, the specific charge amount for neutralizing the potential of the electrostatic latent image with the charge of the toner is 10
It is difficult to obtain a good image quality when the thickness is up to 1000 μc / g. For example, PCT / AU-42-00665
The ink jet recording inks described in the examples of the specification of WO93 / 1186 are those of Examples 1, 2, and 3.
Both have a specific charge of about 0.1 to 0.5 μc / g (Q / M)
The discharge voltage of this ink was as high as 500 to 5000 volts.

Further, an organic pigment or a pigment such as carbon black is simply dispersed in an isoparaffinic solvent, and the pigment in the ink is liable to settle and the uniform flight of the ink and the fixability of the flying ink are poor. is there. In addition, the flying dot diameter of the ink was large, and the resolution and sharpness were degraded.

In the case of the electrophotographic method, the specific resistance for causing the toner particles to migrate to the electrostatic latent image for development is 10 ^10.
It is difficult to obtain a good image quality when the value is Ωcm or more. In particular, sharpness and resolution decrease.

In the conventional inkjet recording ink, the specific charge amount (Q / M) of the colorant particles cannot be obtained because the dye or the like is dissolved in the dispersion medium. Q for distributed type
The value of / M is generally low, and the specific resistance is 10 ⁸ or less.

In the case of wet color image formation, that is, multicolor image formation by color mixing of colorants of different colors, conventionally,
In order to avoid the problem that the colorant of one color in the lower layer is hidden by the colorant of another color in the upper layer and the color of the upper layer becomes dominant and faithful color reproduction cannot be performed, and the specific gravity of the dispersion medium and dispersoid In order to eliminate the adverse effects caused by the difference, it is desirable to use a colorant that is dissolved like a dye, avoiding pigment particles, and thicken a large amount of ink containing the dye at a low concentration in the medium. Since it has been a general aim to achieve a color mixture between different colorants as biasably as possible by use, the present invention results in a direction rather than that of the prior art. It can be said that they are in different directions.

In preparing such an ink composition according to the present invention, each ink raw material must be checked very carefully and the necessary measures taken for unwanted raw materials. That is, the dispersion medium liquid and the colorant are carefully selected, and if necessary, the colorant is purified to remove impurities that cause an increase in the specific resistance, and more carefully the resin component used as the dispersoid. It is necessary to check the above and, if necessary, repeat the elaborate purification to remove impurities that cause an increase in the resistivity therein, and this point is necessary for carrying out the present invention satisfactorily. This is one of the main points of interest and one of the reasons why the ink composition of the present invention is unique as compared with conventional ink jet compositions.

The decrease in the specific resistance of the ink composition, that is, the increase in conductivity depends, of course, on the type, density and mobility of the electrically conductive carrier. Therefore, it is necessary to minimize the inclusion of ions as charge carriers in this type of liquid ink. Therefore, it is necessary to carefully select the liquid dispersion medium and colorant, or to perform purification for ion removal if necessary. Although there is no need to say that it is necessary, for electrons or holes as another carrier, change in band conduction structure under high voltage application and increase of molecular chain segment rotatory property of resin component in liquid dispersion medium. It should be noted that more rigorous component selection is necessary in consideration of the increase in carrier density and mobility due to the increase in mobility associated with. The repeated and elaborate refining of the resin material is a result based on these points. Thus, this careful purification not only removes ions, but also undesired small molecule contaminants.

Further, the ink is dried at 120 ° C.
It was confirmed that when a melt viscosity of 0.1 to 10,000 pa · s (Pascal · second) was used, the ink ejection was uniform and the size of the printed dot diameter was constant. The present invention has been made based on these findings. The present invention will be described in more detail below.

The ink (charged particles) of the present invention has a melt viscosity of 0.1 to 10,000 pa · s (Pascal · second),
Preferably 10 to 5,000 pa · s (Pascal · second)
belongs to. The specific resistance of the ink is 10 ¹⁰ Ωcm or more, preferably 10 ¹¹ Ωcm or more.

The melt viscosity of the ink is 10 pa.
If it is s (Pascal · second) or less, the diameter of the flying dot of the ink is large and the diameter of the printing dot is large, which makes it difficult to increase the resolution. Further, the fixability is lowered. Also 10,000
Ink of 0 pa · s (Pascal · second) or more causes variations in the dot diameter of the ink. Regarding the ink dischargeability, when the ink having a high specific resistance is used, the solid content of the discharge ink is high, and when the ink having a low specific resistance is used, the solid content of the discharge ink is low, but when the specific resistance of the ink exceeds 10 ¹⁰ Ωcm. The solid content rate is such that the density, resolution and contrast of the recorded image are appropriately improved to achieve high density and high resolution.

In the present invention, the particle size of the charged particles is 0.
It is from 01 to 10 μm, preferably from 0.03 to 5.0 μm. If the particle size is 10 μm or more, the fixability becomes poor, and problems such as sedimentation occur. If it is less than 0.01 μm, there is a problem that the ejection performance of particles is insufficient, the applied voltage must be slightly increased, and the ink bleeding phenomenon occurs.

As the dispersion medium in the present invention, water, alcohols, aliphatic hydrocarbons, fatty acid esters, fluorine-based solvents,
Silicon oil or the like is used. Examples of water include distilled water, ion-exchanged water, and tap water. Examples of alcohols include ethyl alcohol, isopropyl alcohol, butanol, propanol, hexyl alcohol, and nonyl alcohol. Aliphatic hydrocarbons include hexane and heptane. , Octane, isododecane, commercially available products such as Isopar G, Isopar H, Isopar L, Isopar M, Isopar V (all manufactured by Exxon), Shell Sol-71 (manufactured by Shell Petrochemical Co., Ltd.), and the fatty acid ester is isopropyl myriline. Higher fatty acid esters such as STATE, isobutyl myristate, hexyl myristate, isopropyl oleate, isobutyl octoate, etc. are mentioned, and as the fluorine-based solvent, Fluorinert FC-40 and Fluoriner manufactured by Sumitomo 3M Ltd. F
C-43, Fluorinert-70, Fluorinert-77 and the like can be mentioned. As the silicone oil, dialkyl silicone oil, cyclic polydialkyl silicone oil, methylphenyl silicone oil, methyl hydrogen silicone oil, modified silicone oil as reactive silicone oil, Examples include non-reactive silicone oil.

Examples of the dialkyl silicone oil include dimethyl polysiloxane and dilauryl polysiloxane manufactured by Shin-Etsu Chemical Co., Ltd., and specifically, trade name KF96L-.
1, KF96L-5, KF995, KF994, KF9
6L-20 and the like, and methylphenyl silicone oil such as KF56 and KF58. These dispersion media have a viscosity of 100 cp or less, preferably 10 cp or less.

The colorants usable in the present invention include Printex V, Printex U, Printex G,
Special Black 15, Special Black 4, Special Black 4-B (made by Tegusa), Mitsubishi # 4
4, Mitsubishi # 30, Mitsubishi MR-11, Mitsubishi MA-100
(Made by Mitsubishi Kasei Co., Ltd.), Raven 1035, Raven 1
252, NEWSPECT 11 (all produced by Columbia Carbon Co., Ltd.), Regal 400, Regal 660, Black Pearl 900, Black Pearl 1100, Black Pearl 1300, Mogall L (all made by Cabot Co.) and other 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,
Resor Fast Yellow 2G, Permanent Red 4R, Brilliant First Scarlet, Hansa Yellow, Benzidine Yellow, Resor Red, Lake Red C, Lake Red D, Brilliant Carmine 6
B, Permanent Red F5R, Pigment Scarlet 3B Indigo, Thioindigo Oil Pink and Bordeaux 10B. The colorant is refined to increase the resistivity of the ink as previously described.

The above colorant can be treated with oil, resin, varnish and the like by kneading and pulverizing with a two-roller, flasher or the like to treat the pigment. This flash colorant surface-treated with a resin or the like increases the Q / M and the specific resistance of the ink, and improves the ejection property of the ink and the solid content content of the ejected ink. As the resin used for the resin treatment, a rosin-modified resin, a silicon-containing resin, an acrylic resin, a polyolefin, or a copolymer thereof is suitable.

As the ink material, it is desirable to further use the following materials as additives in order to improve dispersibility, polarity control, fixability, control of specific charge amount (Q / M) and the like. A silicon-containing copolymer is effective as the additive here.
This compound has the following general formula (I) in the presence of a polymerization initiator in a specific aqueous solution.

[0031]

[Chemical 1] A non-aqueous silicon-containing copolymer obtained by polymerizing a polymerizable silicon compound represented by and a copolymerizable monomer.

Examples of the monomer copolymerizable with the compound represented by the general formula (I) include lauryl methacrylate, 2-ethylhexyl methacrylate, stearyl methacrylate and lauryl acrylate as monomers which are solvated after polymerization in a non-aqueous solvent. And methacrylic acid, fumaric acid, itaconic acid, maleic anhydride,
Copolymers of polar group-containing monomers such as glycidyl methacrylate, hydroxyethyl methacrylate, and dimethylaminoethyl methacrylate are also suitable.

Further, it can be used as a cross-linked polymer obtained by copolymerizing a cross-linkable monomer, styrene, methyl methacrylate, n-butyl methacrylate and the like.

Specific examples of the compound represented by formula (I) are shown in Table 1.

[0035]

[Chemical 1]

[0036]

[Table 1]

The shape of the charged particles in the present invention varies depending on the production conditions and the like, but it is preferably fiber-like or spherical. It is considered that the reason for this is that the presence of fibers on the surface of the ink particles enhances the cohesive force between the particles and improves the ejection property and the fixing property. Further, in the case of a spherical shape, the discharge voltage can be lowered.

The production examples of the resin used in the present invention are as follows.

Production Example-1 of Additive Resin (Example Especially Considering Fixability) Polymerization solvent (Isopar H) 200 g Vinyltoluene 50 g Lauryl methacrylate 50 g Dimethylaminoethyl methacrylate 0.5 g Azobisisobutyronitrile 5 g Composition The product was placed in a three-necked flask and polymerized at 80 ° C. for 6 hours. A polymer having a polymerization rate of 93% and a viscosity of 30.4 cps was obtained. The polymer was repeatedly purified with methanol, Isopar H and toluene. The ink composition using the resin according to this type of production example has excellent fixability.

Resin Production Example-2 (Example in which ink insulation and ejection properties are taken into consideration in particular) Polymerization solvent (silicone oil KF96L-1.5) 200 g Humate 10 g FM-0711 (reactive silicone) 30 g Styrene 10 g A composition consisting of 3 g of maleic anhydride and 3 g of benzoyl peroxide was placed in a three-necked flask and polymerized at 90 ° C. for 8 hours. A polymer having a polymerization rate of 92% and a viscosity of 15 cps was obtained. The polymer was repeatedly purified with methanol, toluene and silicone oil. The ink using the resin according to this type of manufacturing example has excellent insulating properties and ink ejection properties.

Production Example 3 of Resin (Example in Consideration of Charging Characteristics in particular) Polymerization solvent (isopropyl myristate) 200 g Vinyltoluene 10 g Vinylpyrrolidone 10 g Allyl methacrylate 10 g Azobisisobutyronitrile 3 g A composition consisting of 3 g was placed in a three-necked flask. The reaction was carried out at 85 ° C for 10 hours.

Next, 20 g of isobutyl methacrylate, 10 g of acrylic acid and 1 g of benzoyl peroxide were added to this reaction product and dispersed at 90 ° C. for 6 hours to obtain a polymerization rate of 89.
%, A resin dispersion having a viscosity of 18 cp was prepared. This dispersion was purified with methanol and isopropyl myristate.
It is also possible to prepare a polymer pigment by mixing a colorant in a monomer or a dispersion medium and polymerizing the mixture to obtain the ink composition of the present invention. Also in this case, the polymer pigment is carefully purified with alcohol or the like in order to prevent a decrease in the specific resistance under voltage / application. The ink using the resin according to this type of production example using vinylpyrrolidone has its charging characteristics taken into consideration in advance.

[0043]

EXAMPLES The present invention will be described in more detail by way of specific examples.

Example 1 Carbon (Mitsubishi # 44); purified with methanol and toluene 10 parts by weight Humic acid / polyvinylpyrrolidone / methacrylic acid copolymer (50/45/5 weight ratio) 20 parts by weight Lauryl alcohol 300 parts by weight Parts This ink composition was dispersed for 4 hours with an attritor. This product had a specific resistance of 1.6 × 10 ¹¹ Ωcm and a melt viscosity at 120 ° C. of 70 pa · s. When ink was ejected from a distance of 10 mm between each ejection part and the electrode or the printing substrate (1) in the later-described inkjet ejection device (A method, B method, C method), 310 A was used for the A method and 310 V was used for the B method. Ink was ejected at an applied voltage of 460 V and 510 V in the C method. The solid content of the ink before ejection is 9.1%, and the ink ejected by the A method is 26.
The solid content was 5%, the B system was 30.3%, and the C system was 25.5%.

The primary fixability is 11 minutes and 28 seconds (time until the ink ejected on the paper is fixed (sec)),
The secondary fixing property is 62% (measured by the clock meter method), and the image density is 1.28 (according to [density after 5 times of eraser erase / initial print density] × 100 (%)).
And the printing dot diameter was measured by method A: about 76 μm.

Comparative Example 1 For comparison, a commercially available ink (INK C manufactured by EPSON Co., Ltd.) was used.
The same test as in Example 1 was performed using ARTRIDGE HG ICI). 5000 for A system, B system, and C system
No ink was ejected even with the bolt. The Q / M of this ink was 0 and the specific resistance was 10 ⁸ Ωcm or less.

The inkjet ejection test device shown in FIG. 1 (system A), shown in FIG. 2 (system B), and FIG.
(C method) shown in Fig. 4 (D method)
Was used. That is, in the A method, ink is put in the syringe (2), and the (high voltage power supply), that is, V. P (High voltage
Power source) A voltage was applied from a direct current (DC) (6) and the applied voltage at which the ink was ejected from the electrode or the printing substrate (1) from a distance of 10 mm was measured. Similarly, B method is nail (3)
In the method C, the ink is applied evenly to the side surfaces of the flat copper electrode plate (4). D
In this method, the printing substrate (1) is set on the display (5) (here, the static electricity of the display of NEC9801 is used), and the voltage at which the ink is ejected from the tip of the syringe (2) or the nail (3) is set. It was measured. The ink of the present invention is characterized in that it can be ejected with both positive and negative applied voltages.

(Specific Resistance (R) Measuring Method) Brass Electrode 40
20 ml of the sample is placed in an electrodeposition cell of mm × 50 mm, the distance between the electrodes is 10 mm, and the capacity is 20 ml, and the applied voltage DC1 is applied to the sample.
Apply at 000 volts (E) for 50 seconds. The current value (I) when applied for 50 seconds is measured and calculated from the following equation. (Measurement of flow diameter) Measured with a SACP-3 particle size distribution meter manufactured by Shimadzu Corporation. (Melt viscosity) It is measured at 120 ° C. by a dynamic spectrometer manufactured by Rheometrics. (Electron micrograph of toner) Transmission electron microscope (Hitachi H-
Observe at 500H). (Measurement method of specific charge (Q / M)) Brass electrode 40 mm x
20 ml of the sample is placed in an electrodeposition cell of 50 mm, the distance between the electrodes is 10 mm, and the capacity is 20 ml.
Apply with a bolt for 50 seconds. Q / M is calculated from the following formula by measuring the weight of the ink electrodeposited on the electrode plate and measuring the integrated charge amount. Q / M = accumulated charge (μc) / weight of electrodeposit (g)

Example 2 Pigment No. 25 (manufactured by Morimura Burdesh) 10 parts by weight Lauryl methacrylate / glycidyl methacrylate / vinyl pyridine (80/15/5 molar ratio) copolymer 5 parts by weight Humate 5 parts by weight Isopar H 300 parts by weight This ink composition Disperse with an attritor for 3 hours. The average particle size was about 0.1 μm, the Q / M was 155 μc / g, the specific resistance was 1.5 × 10 ¹² Ωcm, and the melt viscosity at 120 ° C. was 16.5 p · s. A method, B method,
In the C type discharge experiment device, when ink was discharged from a distance of 10 mm between each discharge part and the electrode or the printing substrate (1), 260 V was applied in the A type, 240 V in the B type, and 460 V in the C type. Ink was ejected at a voltage. The solid content of the ink before ejection is 6.2%, and the ejected ink is A method 25.4%, B method 29.1.
% And C method 30.5%. In both cases, the solid content of the ink increased. Primary fixing 48 seconds Secondary fixing 71% Image density 1.40 Print dot diameter A: Approx. 50 μm

Comparative Example 2 A test was carried out in the same manner as in Example 2 except that a commercially available ink (IBM INK Cartridge) was used, but ink discharge was observed even with an applied voltage of 5000 V in A method, B method and C method. I couldn't do it. Specific charge (Q
/ M) was 0, and the specific resistance was 10 ⁸ Ωm or less.
Further, the above-mentioned additives lauryl methacrylate / glycidyl methacrylate / vinyl pyridine (80/15/1
(5 mol ratio) The ink excluding the copolymer and humic acid is 620 V for A method, 1200 V for B method, and 1 for C method.
Ink was able to be ejected at a voltage of 000 V, but Example 2
Rather, a high voltage was required to eject the ink. Specific charge (Q /
M) was 65 μc / g.

Example 3 Flashed Pigment No. 5 (manufactured by Morimura Birdesh Co., Ltd.) 10 parts by weight Silicone oil (KF96L-1.5) 300 parts by weight This ink composition was dispersed with a paint shaker for 6 hours. Particle size is about 0.3 μm, specific charge (Q / M) is 32
The resistance was 0 μc / g, the specific resistance was 1.6 × 10 ¹⁴ Ωm, and the melt viscosity at 120 ° C. was 160 p · s. When ink was ejected from a distance of 10 mm between each ejection part and an electrode or a printing substrate (1) in an inkjet ejection experiment device (A method, B method, C method), 210 A for A method and 245 V for B method. In the C method, ink was ejected with an applied voltage of 105 volts. In addition, in the device using the D-type display (5), 10 from the syringe (2)
Ink was ejected from a distance of 0 mm and 80 mm from the tip of the nail (3). The solid content of the ink is 3.2%, the ink ejected from the A method is 29.4%, the B is 32.6%, and the C is
Was 28.2%. Primary fixability 30 seconds Secondary fixability 70% Image density 1.40 Print dot diameter 42 μm

Example 4 Flashed Pigment No. 1 (manufactured by Morimura Burdesh Co., Ltd.) (purified with methanol) 10 parts by weight Resin of Production Example-2 (refinedly purified with methanol and toluene) 20 parts by weight Silicone oil (KF995) 300 parts by weight This ink composition is used with an attritor. Dispersed for 3 hours. Particle size is about 0.1 μm, specific charge (Q / M) is 660 μc
/ G, specific resistance 3.8 × 10 ¹³ Ωm, melt viscosity at 120 ° C. was 460 p · s. When an ejection experiment was performed in the same manner as in Example 3, ink was ejected at an applied voltage of 280 V in the A method, 300 V in the B method, and 300 V in the C method. When the D type display (5) was used, ink was ejected from the syringe (2) at a distance of 130 mm and from the tip of the nail (3) at a distance of 95 mm.

In the test using the test apparatus shown in FIG. 5, ink could be ejected with an applied voltage of 150 volts.
In addition, when using this device having a discharge port diameter of 25 μm and using an ink composition in which an organic pigment is dispersed in an in-paraffin-based liquid having an initial distilling point of 159 ° C., ink is discharged from a distance of 90 mm. Discharge was possible at a lower voltage as compared with the voltage of 1000 V. Primary fixing property 40 seconds Secondary fixing property 75% Image density 1.38 Printing dot diameter Approx. 40 μm D-type display (5) is printed on paper on the paper (5) 100 mm away from the syringe (2) while ejecting ink to clean it manually. I was able to write letters.

Example 5 Polymerized toner (spherical shape having a particle size of 0.3 μ) 20 parts by weight Silicone oil (KF994) 300 parts by weight This ink composition was dispersed for 3 hours with an attritor. Particle size is about 0.3 μm, specific resistance 3.5 × 10 ¹² Ωm, 12
The melt viscosity at 0 ° C. was 6,300 p · s. The ink had a negative polarity. When an ejection test was performed in the same manner as in Example 3, ink was ejected at 200 V in the A method, 210 V in the B method, and 300 V in the C method.
Also, in the D-type display (5), 1 with the syringe (2)
Ink was ejected from a distance of 60 mm and 135 mm from the nail (3). Primary fixing property 18 seconds Secondary fixing property 76% Image density 1.46 Print dot diameter 30 μm Further, heat roller fixing was possible. When discharged in the same manner with a negative applied voltage, (-) 210 V for the A method, (-) 120 V for the B method, and (-) for the C method.
Ink was ejected at 180 volts.

Example 6 Carbon black (manufactured by Mitsubishi Kasei) # 44 20 parts by weight Ethylene / vinyl acetate copolymer (85/15 parts by weight) 10 parts by weight Silicone oil (KF96L-1.0) 300 parts by weight This ink The composition was dispersed at 50 ° C. for 1 hour and quenched.
Particle size is about 1.8μm, specific charge (Q / M) is 40μc
/ G, specific resistance 4.4 × 10 ¹⁴ Ωm, melt viscosity 120 ° C.
It was 800 p · s. The shape of the particles in the electron micrograph was fiber-like. When a discharge test was conducted in the same manner as in Example 3, it was 260 V for the A method, 260 V for the B method, and 360 V for the C method. Primary fixability 5.8 seconds Secondary fixability 89% Image density 1.51 Print dot diameter approx. 24 μm Because charged ink particles are fibrous, it is possible to slowly eject strong aggregates of ink by the applied voltage. Conceivable. Therefore, it is presumed that the above good results can be obtained. When this ink was printed on a bubble-jet printer manufactured by Canon Inc., a print with high density and good fixability was obtained.

Example 7 In the ink formulation of Example 2, lauryl methacrylate / grindyl methacrylate / vinyl pyridine (80 /
(15/15 molar ratio) 20 parts by weight of copolymer and 15 parts by weight of humic acid were added and dispersed for 3 hours with an attritor. Average particle size 0.04 μm, Q / M 980 μc / g, 120
The melt viscosity at 0 ° C. was 2800 pa · sec.
Ink ejection property is 280 V for A method and 30 for B method.
Ink was discharged with an applied voltage of 0 volt and 305 volt in the C method. The primary fixability is 62 seconds and the secondary fixability is 74
%, The image density was 1.36, and the print dot diameter was as small as 48 μm.

Example 8 In Example 7, 1 part by weight of the copolymer was added to 0.1 parts by weight of humic acid.
An ink was prepared in the same manner by adding parts by weight. The average particle size of the ink was 0.9 μm, the Q / M was 12 μc / g, and the melt viscosity at 120 ° C. was 10.8 pa · sec. Ink ejection properties are 460 V for A method, 495 V for B method, 600 V for C method, primary fixing property 69 seconds, secondary fixing property 60%, image density 1.21, print dot property 86 μm.
Met.

Example 9 (Example of ink composition having large Q / M of charged particles and high electric resistance of ink composition) In Example 6, carbon black purified with toluene and ethanol was used. Similarly, ink was created. Average particle size is 2.5
μm specific resistance is 1.5 × 10 ¹⁶ Ω · cm, melt viscosity at 120 ° C. is 980 pa · sec, Q / M is 580 μc
/ G. 245 volts for A method, 2 for B method
It was 50 volts and 340 volts in the C system. The primary fixability was 5.6 seconds, the secondary fixability was 89%, the image density was 1.53, and the print dot diameter was about 22 μm. Ink with high image density and high fixability was obtained with a small dot diameter.

(Example of Ink Composition with Small Q / M of Charged Particles and Low Electric Resistance of Ink Composition) Example 10 Manganese naphthenate 0.02 was added to the ink formulation of Example 1.
An ink composition was similarly obtained by adding gr. The specific resistance of this product is 1.5 × 10 ¹⁰ Ωcm, Q / M is 48 μc / gr,
The average particle size is 0.8 μm and the melt viscosity at 120 ° C. is 6
It was 5 pa · sec. 460 volts for A system, B
Ink was ejected with an applied voltage of 500 V in the method and 620 V in the method C. The solid content of the ink before ejection is
The solid content was 20.6% for the 9.1% A method, 24.1% for the B method, and 23.1% for the C method. The primary fixability was 13 minutes and 5 seconds, the secondary fixability was 60%, the image density was 1.21, and the print dot diameter was about 83 μm. The results are summarized in Table 2 below.

[0060]

[Table 2]

Example 11 100 parts of Isopar H, 15 parts of phthalocyanine blue, and a methacryl-modified silicon compound (X: manufactured by Shin-Etsu Chemical Co., Ltd.)
-22-5002) 30 parts, 2,4-tolylene diisocyanate 5 parts, BPO (benzoylperoxide) 3 parts and acrylic acid 2 parts were charged in a flask and reacted at 90 ° C for 12 hours while stirring well. To produce a cyan dispersion liquid (C) containing cyan resin particles.

50 g of the cyan color dispersion C was dispersed in 1 liter of Isopar H to prepare an electrophotographic liquid developer, and this developer and a wet copying machine CT-5085 manufactured by Ricoh were used to produce the same copying paper as in Example 1. The image was copied to obtain a high-quality copied image having an image density of 1.29, a resolution of 6.3 lines / mm, and a gradation of 7.0 steps. Further, the image fixing rate was 68%, and it was confirmed that the liquid developer produced by diluting the cyan color dispersion C used in this experiment had good fixability and dispersibility.

Example 12 Instead of the methacryl-modified silicon compound used in Example 11, the reactive silicon compound No. 1 shown below was used. Cyan Color Dispersion Liquid D was prepared in the same manner as in Example 11 except that No. 4 was used. This dispersion was diluted as in Example 11 to obtain a liquid developer, and the same evaluation experiment as in Example 11 was conducted using this developer. Image density 1.44, resolution 7 A high-quality copied image with 0.2 lines / mm and gradation of 7.0 steps was obtained. In addition, the cyan color dispersion D prepared in this example is a colorant which gives a water- and oil-repellent copy image and which can be fixed by a heat roller. And the image fixing rate is 81%
It was extremely expensive.

The cyan color dispersion D obtained in this example is
There are many advantages as an inkjet ink such as a slit jet method, a piezo jet method, and a bubble jet method using a pin electrode, and the inkjet ink has good ejection properties and image quality.

[0065]

[Chemical 2]

Example 13 300 g of Isopar H (manufactured by Exxon Chemical Co.) in a flask
It was taken and heated to 90 ° C. 50g of Kayaset Yellow AG, silicon oligomer X-22-176B
100 g (manufactured by Shin-Etsu Chemical Co., Ltd.) was taken and mixed at 90 ° C. for 3 hours. 50 g of methyl methacrylate, 3 g of glycidyl methacrylate, 30 g of isophorone diisocyanate and 0.5 g of BPO (benzoyl peroxide) were added to this mixed solution,
Dispersion was carried out at 90 ° C. for 6 hours to prepare an electrophotographic liquid developer. Here, a silicon oligomer X-2 having a hydroxyl group
Since 2-176B reacts with isophorone diisocyanate to form a urethane bond, it is considered that polymer toner particles containing a pigment can be prepared.

This developer was used as a recopy 400 manufactured by Ricoh Company.
Fixing rate of 80%
And the OPH color reproducibility was also good. Fixation rate = (ID / ID after 10th floor of clock meter) x
100%

Example 14 Ethylene-maleic anhydride copolymer 5 was placed in a kneader kneader.
00 g, 2,2,4-trimethylpropanetriisophorone diisocyanate 15 g and Carmine 6B 200 g were taken and kneaded at 100 ° C. for 1 hour. Next, 150 g of lauryl methacrylate, 30 g of glycidyl methacrylate, B
2 g of PO was mixed and polymerized at 90 ° C. for 6 hours. Next, 0.1 g of dodecylamine was added and the esterification reaction was carried out at 80 ° C.
I went there for 20 hours. Further, 1200 g of Isopar H was added to prepare an electrophotographic liquid developer. This developer was able to be fixed by hot air at 80 ° C. with Recopy 400i. The fixing rate was 88% and the OHP color reproducibility was also good.

When copying was carried out by the backside fixing method at 120 ° C. with Recopy 400i, the fixing rate was 74%, and the color reproducibility of OHP was slightly inferior to that of the warm air fixing method, but almost good. The electrophotographic liquid developer obtained in Example 14 can be used as an ink for inkjet recording, like the developer obtained in Example 13.

[0070]

As is clear from the above results, according to the present invention, many excellent effects can be obtained. This is because the influence of the charged particles of the ink and the flight mode are as described above. In a sense, it is considered to be unique in the invention. FIG. 6 is a model for explaining the conceptual flight difference between the ink of the present invention and the conventional inkjet ink, and 6a is a book in which the solid content of the flight ink is increased. The flight mode of the ink of the invention is shown as a model, and 6b shows the flight mode of the conventional inkjet ink as a model. However, the flight model proposed above is
It is intended to aid the understanding of the present invention, and we are not stubbornly bound to this model, nor are we intended to limit the invention thereto. The essence and effects of the present invention should be fully understood by the parties based on the above specific examples and the results thereof.

Further, according to the novel method for producing a colorant used in electrophotographic liquid developers, ink jet inks, printing inks, paints, etc. according to the present invention, the image density is high and the resolution, contrast and gradation are high. A colorant capable of providing an image with excellent tonality can be obtained, and according to this manufacturing method, a colorant having a high fixability after image formation and having an image with a water / oil repellent coating film can be obtained. The effect of being able to be played.

Thus, according to the present invention, an appropriate flying dot diameter of ink can be obtained, and a high quality image can be obtained. In addition, there is no settling of charged particles, no ink bleeding phenomenon is observed, a good quality image is obtained at the point where there is no image bleeding, good quality ink can be adjusted, the specific resistance is increased, and the ink ejection property is improved. Improve ink dispersibility, polarity control, fixability,
Control of specific resistance is improved. Further, the ink jet method using these inks can change the cohesive force between the ink particles, and the image is further improved in terms of improving the ejection property and the fixing property.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing an outline of an inkjet ejection experiment device.

FIG. 2 is an explanatory diagram showing an outline of an inkjet ejection experiment device.

FIG. 3 is an explanatory diagram showing an outline of an inkjet ejection experiment device.

FIG. 4 is an explanatory diagram showing an outline of an inkjet ejection experiment device.

5 is an explanatory diagram showing an outline of an apparatus used for a test of the ink composition of Example 4. FIG.

FIG. 6 is an explanatory view conceptually showing the difference in ink flight between the present invention and the prior art.

[Explanation of symbols]

1 electrode or printed substrate 2 syringes 3 nails 4 Copper electrode plate 5 display 6 High voltage DC power supply 7 conductors 8 ink supply pipe 9 discharge points 10 Ink supply system 11 Recovery ink flow direction 12 Ink collection path 13 Outside extraction system 14 Voltage source

─────────────────────────────────────────────────── ─── Continuation of front page (31) Priority claim number Japanese Patent Application No. 6-289055 (32) Priority date October 28, 1994 (October 28, 1994) (33) Country of priority claim Japan (JP) (31) Priority claim number Japanese Patent Application No. 6-333881 (32) Priority date December 16, 1994 (December 16, 1994) (33) Country of priority claim Japan (JP) (72) Inventor Akihiko Goto Ricoh Co., Ltd. 1-3-3 Nakamagome, Ota-ku, Tokyo (72) Inventor Kazuhiko Umemura 1-3-6 Nakamagome Nakamagome, Ota-ku, Tokyo (72) Inventor Kazuyo Mizuno Tokyo Inc Ricoh Co., Ltd. 1-3-6 Nakamagome, Ota-ku, Tokyo (72) Inventor Shin Ogawara 2-81-211 Ookayama, Meguro-ku, Tokyo (56) Reference JP-A-58-49276 (JP, A) JP-A-2-29474 (JP, A) JP-A-2-29472 (JP, A) JP-A-7 17041 (JP, A) JP 5-261979 (JP, A) JP 5-261911 (JP, A) JP 5-261903 (JP, A) JP 4-50951 (JP, A) JP-A-4-182674 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) C09D 11/00-11/20 B41J 2/01-2/21 B41M 5/00-5 / 40

Claims (7)

(57) [Claims] 1. An ink composition containing, as a main component, charged particles containing at least a dispersion medium and a coloring agent is used, and the charged charged particles are caused to fly from an ink ejection section to a charged substrate or by an applied voltage. A wet toner jet recording method in which the charged particles are ejected onto a substrate to perform image recording, wherein the ink composition satisfies at least one of the following conditions A and B , and also satisfies the following condition C: Minutes
Silicon oil, fatty acid ester, fluorine
Yl, aliphatic hydrocarbon, or alcohol
Liquid toner jet recording method characterized by there. A: Specific charge amount (Q / M) of charged particles is 10 to 1,000
μc / g. B: The electric resistance of the ink composition is 10 ¹⁰ Ωcm or more. C: The average particle diameter of the charged particles is 0.01 to 10 μm,
The melt viscosity is 0.1 to 10,000 pa · sec. 2. The surface of the coloring agent is resin or oil.
The wet toner jet recording method according to claim 1, further comprising : 3. The ink composition is a silicon-containing polymer,
Polyolefin or copolymer with olefin, rosin
3. The wet toner jet recording method according to claim 1 , further comprising a modified resin thereof . 4. The charged particles are spherical, fibrous or
The wet toner jet recording method according to any one of claims 1 to 3, wherein is a mixture of irregular shapes.
Law . 5. The charged particles are a colorant or a polymerizable monomer.
Polymer and toner obtained from a system whose main component is a non-aqueous solvent
Liquid toner jet recording method according to any one of claims 1 to 4, characterized in that it is over. 6. A colorant and a non-aqueous solvent at 40 ° C. or higher
Or a system containing at least a softening polymer substance,
The wet toner jet recording method according to any one of claims 1 to 5, wherein a monomer and a polymerization initiator are mixed and polymerized . 7. A pigment and / or dye and active water as raw materials
And reactive isocyanate compounds
Compound and at least these raw materials in a non-aqueous solvent
The coating obtained by heating and reacting the dispersed dispersion
The ink according to claim 1, wherein a colorant is used.
A method of making a composition.