JP3506294B2 - Ink composition and recording method using the same - Google Patents

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to an ink composition for ink jet recording and a recording method using the ink. Further, the present invention relates to an electrophotographic toner and an electrophotographic recording method using the same.

[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.

On the other hand, various types of ink compositions used in the ink jet recording system have been devised, and recently, it has been proposed to employ a wet toner in the ink jet recording system.

As an example of the wet toner jet recording method, a method of applying a voltage having the same polarity as the polarity of the toner particles to the tip of the line head to form agglomerates of the toner particles and discharging the agglomerates to perform printing (PCT / AU92-
[00665, PCT / WO93-00118) 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. Kaihei 6-348071 and Japanese Unexamined Patent Publication No. 7-160062) are proposed.

US Pat. No. 3.060.429 describes an electrostatic ink jet 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 fogging on paper.
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 many water-soluble organic solvents have been studied. It has been conventionally proposed to use an activator and a block copolymer of ethylene oxide and propylene oxide (see, for example, JP-A-62-89776). 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.

However, none of the conventionally proposed ink jet recording inks satisfies all of the above five 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.

On the other hand, in the field of electrophotographic wet developers, two or more kinds of resin components having different properties are mixed and used, or a resin obtained by copolymerizing two or more kinds of different monomers or prepolymers. It is conventionally known to use components, for example, JP-A-63-293558 discloses that two or more polymers are contained in a non-polar liquid having a kauributanol value of less than 30 (eg, branched chain aliphatic hydrocarbon). (One of the polymers has a pK value in water at 25 ° C. of less than 4.5 and contains one or more acidic components, such as poly (2-acrylamido-2-methyl-1-
It is described that propanesulfonic acid is used, and the other is resin particles made of an ethylene-methacrylic acid copolymer. JP-A-3-225358 discloses a resin having a methylol group (eg, melamine formaldehyde resin). ) And a resin having a functional group capable of reacting with a methylol group (eg, styrene-acrylic resin), or a modified resin obtained by reacting these two resins is described. The former is to improve the detail toning and resolution and the uniformity of toning, and the latter is to eliminate the need to apply oil to the fixing roll. It does not consider the diameter.

Further, in Japanese Patent Application Laid-Open No. 03-271752, a thermoplastic resin toner particle forming resin is used as an aliphatic polyester oligomer (preferably having a molecular weight of 1000 to 100).
It is a weight body of about 00, and a saturated aliphatic diol and a saturated aliphatic polyester oligomer composed of a saturated aliphatic dicarboxylic acid) are mixed and used at a ratio of 1 to 20 wt% of the thermoplastic resin. Kaihei 03-27175
No. 2 discloses that a thermoplastic resin toner particle-forming resin contains an aliphatic polyester oligomer (preferably a molecular weight of 100).
A saturated aliphatic polyester oligomer composed of a saturated aliphatic diol and a saturated aliphatic dicarboxylic acid) having a weight of about 0 to 10000 and a thermoplastic resin of 1 to 20.
Although it is described that each of them is mixed in the proportion of wt%, the former is for improving the fixing property and the film forming property, and the latter is for the resolution and the solid area coverage. There is no suggestion of a technique for improving the dot diameter of the flying ink to improve the image quality and prevent the image from being crushed. According to JP-A-4-218066 and JP-A-4-226479, (A) a non-polar liquid having a Kauri-butanol value of 30 or less, which is present in a large amount, (B) an area of 10 μm or less. Electrostatic liquid developers consisting essentially of thermoplastic resin particles having an average particle size and a (C) AB diblock copolymer charge control agent compound are described, which produce proof images, lithographs. It is for obtaining a developing solution useful for printing plates, resists and the like. Japanese Patent Laid-Open No. 5-2
No. 41380, a weight obtained by bonding a polymerizable double bond group to the end of the main chain of a polymer containing one of certain polymer components having a linking group such as —COO—. A non-aqueous liquid developer formed by combining a third macromonomer having an average molecular weight of 1 × 10 ³ to 1 × 10 ^{5 and} a fourth monomer is described, which also improves the dispersibility and charge stability. It's just something to do.

[0011]

SUMMARY OF THE INVENTION The object of the present invention is to improve the above-mentioned drawbacks in the prior art, to fly at a low applied voltage and to be excellent in fixing property to a substrate such as paper, plastic, metal and the like, and to have a high image density. Another object of the present invention is to provide an ink composition for inkjet recording capable of printing with high resolution and a toner for electrophotography. Another object of the present invention is to provide a new inkjet recording method using the above ink composition, and to provide a new electrophotographic recording method using the electrophotographic toner. .

[0012]

The object of the present invention is as follows. (1) "The ink ejection portion has a nail shape, a nozzle shape, or a line head shape, and has the same or opposite polarity as the charged particles of the ink. In a wet toner inkjet recording method in which an image is recorded by ejecting ink from the ejecting portion by an applied voltage, the ink is mainly composed of charged particles containing at least a dispersion medium having a kauributanol value of 50 or less, a colorant and a resin. It is a composition and the dry matter of the composition has a softening point of 50 to 125 ° C. or an outflow starting point of 70 to 180.
℃ (according to Koka type flow tester method), the dispersion
Medium is silicone oil alone or mixed with silicone oil
Of fatty acid esters, fluorine oils and aliphatic hydrocarbons
(2) "Wet toner inkjet recording method characterized by being a mixture with any of the above", (2) "The colorant is a colorant capable of developing and erasing at least reversibly, and a leuco dye and a redox dye as the colorant. Or a pigment is used, the wet toner inkjet recording method described in the above item (1).

[0013]

[0014]

The present inventor has conducted earnest studies from various angles on the ink jet recording ink and the ink jet recording method suitable for the ink, without being caught by the common sense of the wet toner used in the conventional electronic recording system. ,
In the ink jet recording method and the wet toner jet recording method, the softening point and the outflow starting point of the ink using a resin when the ink is dried, the dot diameter of the flying ink particles or the dot diameter of the non-contact transfer ink particles, the image density, And, new knowledge was obtained about the relationship between the adhesion to substrates such as paper. That is, if the softening point or outflow starting point of the ink using resin is within a certain range, confirm that the dot diameter, image density, and fixability to a substrate such as paper are satisfied. did. It was also confirmed that the ink using such a resin is extremely useful as a wet toner used in an electronic recording system. The present invention has been made based on these findings. The present invention will be described in more detail below.

As described above, the ink (charged particles) of the present invention has a softening point of 50 to 50 in a dry solid of a recording composition containing charged particles containing at least a dispersion dope, a colorant and a resin as a main component.
The ink composition for ink jet recording is characterized in that it has a temperature of 125 ° C. or an outflow starting point of 70 to 180 ° C. (according to a Koka type flow tester method). Such a dry matter has a softening point of 50 to 125 ° C. or an outflow starting point of 70 to 125 ° C.
By using the ink composition at 180 ° C. for inkjet, it is possible to increase the image density, reduce the dot diameter, and improve the fixability. If the softening point is 50 ° C. or lower and the outflow starting point is 70 ° C. or lower, the dot diameter is large and the fixability is poor. Also, the outflow starting point is 180 ° C or higher,
It was found that when the softening point was 125 ° C. or higher, the image density was low and the fixability was poor.

In the conventional ink jet ink, for example, the softening point and the outflow starting point are 2 in Examples 1, 2, and 3 described in the examples of PCT / AU-42-00665.
The temperature was not lower than 00 ° C, and the fixability was particularly poor.

The present invention is also the ink composition, wherein the dispersion Ume is any one of silicone oil, fatty acid ester, fluorine oil, aliphatic hydrocarbon, or a mixture thereof. Furthermore, the ink ejection portion of the present invention has a nozzle shape (FIG. 1), a nail shape (FIG. 2), or a line head shape (FIG. 3), and is applied with an applied voltage of the same polarity or opposite polarity to the charged particles of the ink. It is characterized by ejecting ink, and for example, an image can be formed using a display as shown in FIG.

The ink composition can be applied to an electrophotographic system in addition to the inkjet. The electrophotographic method here includes not only a method of developing an electrostatic latent image formed on an electrophotographic photosensitive member but also a method of developing an electrostatic latent image formed on a dielectric or an insulator. means. That is,
The present invention provides a squeeze member which is located between a developing portion and a transfer portion of a toner image holding member that holds a developing solution layer and whose moving direction is opposite to the moving direction of the toner image holding member. It can also be used in a wet development transfer system in which a voltage applying member is provided behind the squeeze member, a voltage is applied to the toner image holding member in a non-contact manner to flow a current, and then electrostatic transfer is performed to the transfer member. it can. Furthermore, the colorant is a colorant capable of at least reversibly developing and erasing color, and can be applied to inkjet inks and electrophotographic toner compositions using a leuco dye and a redox dye or pigment as the colorant.

The above-mentioned "enhanced flow tester method" in the present invention is not limited to the one using the tester, but as the above-mentioned elevated flow tester, the present inventor specifically manufactured by Shimadzu Corporation. It measured using the thing. The softening point and the outflow starting point will be described with reference to FIG. 5. The softening point is a point at which the position of the plunger reaches a maximum point when the temperature of the sample is increased from a low temperature to a high temperature. The starting point is the point at which the position of the Plancher takes a minimum value after passing through the softening point.

As the carrier liquid, cycloparan, n-hexane, n-heptane, n-nonane, n-octane, isooctane, isododecane, ligroin and a mixture thereof are commercially available aliphatic hydrocarbons such as Isopar E from Exxon. , Isopar G, Isopar H, Isopar L, Isopar K and Shell Petroleum Shell Sol 71, Solvesso 100, Solvesso 150 and the like can be used. Further, silicone oil, fluorine oil, fatty acid ester and the like are also used.

As the colorant, Printex V, Printex U, Printex G, Special Black 15, Special Black 4, Special Black 4-
B, (made by Dexa), Mitsubishi # 44, Mitsubishi # 30, Mitsubishi MR-11, Mitsubishi MA = 100 (made by Mitsubishi Kasei), Raven 1035, Raven 1252, New Spectra II (made by Columbia Carbon) , Regal 400, Regal 600, Black Pearl 900, Black Pearl 1100, Black Pearl 1300, carbon black such as (made by Cabot), zinc oxide,
Inorganic pigments such as titanium oxide and 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, resole fast yellow. Two
G, Permanent Red 4R, Brilliant Fast Scarlet, Hansa Yellow, Benzidine Yellow, Resole Red, Lake Red C, Lake Red D, Brilliant Carmine 6B, Permanent Red F5R, Pigment Scarlet 3B, Indigo, Thio Indigo,
Organic pigments such as Oil Pink and Bordeaux 10B are mentioned.

Further, as leuco dyes and redox dyes or pigments capable of reversibly developing and erasing, crystal violet lactone, primiple blue, cromonoanaindolizine blue, fluorane compound, p-nitrophenol, eosin, p Examples include cresolphthalein, indigomonosulfonic acid, basic fuchsin, and crystal violet.

As the resin, for example, the following can be preferably used. (A) 2-methacryloyloxyethyl succinic acid 40 mol Copolymer lauryl methacrylate 40 styrene 20 (B) 2-methacryloyloxyethyl maleic acid 30 mol Copolymer glycidyl methacrylate 40 isobutyl methacrylate 30 (C) stearyl methacrylate 30 mol 2- Methacryloyloxyethyl hexahydrophthalic acid 25 Glycidyl methacrylate 40 40 2-Ethylhexyl methacrylate 5 (D) Ethylene glycol dimethacrylate 15 mol Vinyltoluene 50 Maleic anhydride 10 Vinyl acetate 25 Others, polyurethane, epoxy, polyvinyl butyral, polyolefin, silicone, polycarbonate resin Etc. can be used.

The ink and the electrophotographic toner composition according to the present invention contain 50 to 98 parts by weight of a dispersing agent and 40 to a coloring agent.
0.5 parts by weight of resin, 0.5 to 45 parts by weight of resin and, if necessary, a polarity control agent, a dispersant, etc. are dispersed in an attritor, a ball mill, a pin mill or the like to a particle size of about 0.01 to 5 μm. And a toner composition. The present invention will be described in more detail by way of examples.

[0026]

EXAMPLES Reference Example 1 As an example of the resin used in the present invention, 1000 g of the above-described copolymer A, 300 g of Carmine 6B (Fuji Dye Co., Ltd.) and 3000 g of Isopar H were placed in an attritor and dispersed at 60 rpm for 6 hours. The dry solidified recording material had a softening point of 53 ° C and an outflow starting point of 85 ° C.

Example 1 500 g of copolymer B, 35 g of carbon # 44 (Mitsubishi), silicone oil KF9 described above as an example of resin.
200 g of 94 (Shin-Etsu Chemical Co., Ltd.) was dispersed in an attritor for 6 hours, and the dry matter had a softening point of 95 ° C and an outflow starting point of 148 ° C.

Reference Example 2 500 g of Copolymer C, 120 g of Phthalocyanine Blue (Dainichiseika), lecithin 1 described above as an example of resin.
0 g and 1500 g of isopropyl myristate were dispersed in a ball mill for 3 hours. The dry solid had a softening point of 63 ° C and an outflow starting point of 110 ° C.

Example 2 An ink composition was prepared by dispersing 300 g of the copolymer D, 100 g of quinaldine red, 100 g of ethanol and 1000 g of silicone KF995 (Shin-Etsu Chemical Co., Ltd.) described above as an example of the resin in an attritor for 5 hours. did. The dry matter had a softening point of 118 ° C and an outflow starting point of 170 ° C.

(Evaluation Results) The inks of Examples 1 and 2 and Reference Examples 1 and 2 were used in the inkjet discharge test apparatus (A) system shown in FIG. The ink was ejected with a bolt, the ink adhering to the paper was fixed with a 140 ° heat roller, and the image density and fixability were measured by a Macbeth densitometer and a crockmeter method. The results are shown in Table 1 below.

[0031]

[Table 1] The applied voltage was as low as 300 to 500 V, and ejection was possible even with a voltage.

(Comparative Example 1) 1000 g of a lauryl methacrylate / acrylic acid 90/10 mol copolymer, 300 g of carmine 6B and 3000 g of Isopar H were dispersed in an attritor for 6 hours. The softening point of the dried solid matter was 43 ° C, and the outflow starting point was 58 ° C.

Comparative Example 2 A test was conducted in the same manner as in Comparative Example 1 using trimethylolpropane trimethacrylate, styrene and stearyl methacrylate 10/50/40 mole copolymer. Softening point 1
The outflow starting point was 48 ° C and 200 ° C or higher. Example 2
The color tone of the printed matter of (1) could be changed by the decoloring agent, and it could be used as recycled paper.

Further, the toner squeeze member for holding the developing solution layer is located between the developing unit and the transfer unit, and the moving direction of the toner image holding member is opposite to the moving direction thereof. A member, a voltage applying member is provided behind the squeeze member, a voltage is applied to the toner image holding member in a non-contact manner to pass a current, and then electrostatic transfer is performed to a transfer member, a wet development transfer method, recopy A copy was made at 400i (IMP). When Examples 1 and 2 and Reference Examples 1 and 2 and Comparative Examples 1 and 2 are used as electrophotographic developers, the present invention is superior to Reference Examples and Comparative Examples in terms of image density, fixability and resolution. found.

[0035]

[Table 2]

The copy of Example 2 can be decolorized with a decolorizing agent such as phenolic resin, thus providing a deinking method, a regenerating method and a regenerated material. Examples 1, 2 and
It was also found that the present invention products in Reference Examples 1 and 2 are less likely to cause offset during fixing. In Comparative Examples 1 and 2, toner adhered to the heat roller and offset was observed on the copy paper.

[0037]

EFFECTS OF THE INVENTION According to the present invention, an ink jet recorded matter having a good ink ejection property, a high image density and a good fixing property can be obtained. Further, according to the ink composition of the present invention and the recording method using the same, the resolution, image density, fixability, etc. of the recorded matter are further improved by any of the methods. It is considered that these effects are due to the improved dispersibility, thermal characteristics, cohesive force, etc. of the ink composition of the present invention. Furthermore, since the ink composition of the present invention can erase a printed matter or a copied matter with a decoloring agent, it is also effective as a resource-saving one.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing an outline of one inkjet discharge device in the present invention.

FIG. 2 is an explanatory diagram showing an outline of another inkjet ejection device according to the present invention.

FIG. 3 is an explanatory diagram showing an outline of another inkjet ejection device according to the present invention.

FIG. 4 is an explanatory view showing the outline of still another inkjet ejection device according to the present invention.

FIG. 5 is an explanatory diagram showing a softening point and an outflow starting point of the ink composition according to the invention.

[Explanation of symbols]

1 electrode or printed substrate 2 syringes 3 nails 4 Copper electrode plate 5 display 6 High voltage DC power supply

Continuation of the front page (56) Reference JP-A-6-16983 (JP, A) JP-A-5-202324 (JP, A) JP-A-9-251217 (JP, A) JP-A-4-198282 (JP , A) JP 63-201669 (JP, A) JP 63-293558 (JP, A) JP 5-297630 (JP, A) JP 6-3857 (JP, A) JP 7-92731 (JP, A) JP 7-234539 (JP, A) JP 7-244401 (JP, A) JP 2-77 (JP, A) JP 7-502218 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) C09D 11/00-11/20 G03G 9/08-9/10

Claims (2)

(57) [Claims] 1. A wet method in which an ink ejecting portion has a nail shape, a nozzle shape, or a line head shape, and ink is ejected from the ejecting portion by an applied voltage having the same polarity or an opposite polarity to the charged particles of the ink to record an image. In the toner ink jet recording method, the ink is a composition containing, as a main component, charged particles containing at least a dispersion medium having a kauri-butanol value of 50 or less, a colorant and a resin, and having a softening point of a dry solid of the composition. 50-125 ° C or outflow starting point is 70-18
0 a ° C. (by Koka type flow tester method), the amount
The dispersion medium is silicone oil alone or mixed with silicone oil.
Compatible fatty acid ester, fluorine oil, aliphatic hydrocarbon
A wet toner inkjet recording method characterized by being a mixture with any of the above . 2. The colorant is a colorant capable of at least reversibly developing and erasing color, and a leuco dye as the colorant,
2. The wet toner inkjet recording method according to claim 1, wherein a redox dye or a pigment is used.