JP2001179959A - Ink absorber, and imaging apparatus and method using it - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an imaging apparatus in which offset is prevented even when the print speed is increased by absorbing only the liquid solvent of ink adhering onto a sheet. SOLUTION: The ink absorber 130 of an imaging apparatus 100 comprises a liquid solvent absorber 130b for absorbing the liquid solvent of ink, and a mold releasing member 130c covering the surface of the liquid solvent absorber 130b at least partially and passing the liquid solvent of ink while exhibiting mold releasing properties for the coloring agent of ink. Simultaneously with adhesion of ink onto a sheet S or immediate thereafter, the liquid solvent absorber 130b is brought close to a part of the sheet where ink is adhering while holding the mold releasing member 130c in order to absorb the liquid solvent through the mold releasing member 130c. The coloring agent and the liquid solvent of the liquid ink are in phase separation state at least on the sheet.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus and method for forming an image by depositing liquid ink on a recording medium.

[0002]

2. Description of the Related Art In an image forming apparatus such as an ink-jet printer using a liquid ink, ink remaining on a recording medium after printing (after paper discharge) (especially, a liquid solvent (generally water) as a main component of the ink) In the case of printing a large number of sheets, set-off is caused. Therefore, heating to dry the ink quickly,
Many moisture evaporation mechanisms such as ventilation have been proposed.

[0003]

Such a water evaporating mechanism can provide a certain effect when the printing speed is relatively low. However, when it is used for an image forming apparatus having a high printing speed (high speed), the water evaporating mechanism can be used. This is not always sufficient, because the large latent heat of the device requires a large amount of power and the device needs to be enlarged.

On the other hand, as a method for easily removing water,
Means for infiltrating into an absorbing member typified by so-called "absorbing paper" can be considered, but this is nothing but the removal of ink together with the colorant, which causes a problem of lowering image density.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide an image forming apparatus and a method which does not cause set-off even when the printing speed is increased by absorbing only the liquid solvent of the ink attached to the recording medium. And

[0006]

In order to achieve the above object, the present invention provides a liquid solvent absorber for absorbing a liquid solvent of a liquid ink, and at least a part of the surface of the liquid solvent absorber, and Provided is an image forming apparatus having an ink absorber including a release member having releasability from a colorant and transmitting a liquid solvent of ink. In this image forming apparatus, almost simultaneously with or immediately after the ink has adhered onto the recording medium, the liquid solvent absorber is brought close to the recording medium portion to which the ink has adhered with the release member interposed therebetween, whereby
The liquid solvent is absorbed by the liquid solvent absorber through the release member. The liquid ink is in a state where the colorant and the liquid solvent are phase-separated at least on the recording medium.

[0007]

Embodiments of the present invention will be described below with reference to the accompanying drawings. In the following description, an ink jet printer is used as an image forming apparatus. However, the present invention is applied to all image forming apparatuses using liquid ink or liquid toner, such as gravure printing and liquid development type electrophotography. be able to.

[0008] The ink which can be used in the present invention comprises a colorant (pigment or dye) and a liquid solvent (generally water) on a sheet.
Is an ink capable of forming a phase-separated state (details will be described later).

(First Embodiment) FIG. 1A shows a part of a printer 100 having an ink jet head 1.
The printer 100 includes a bottom plate 102 and the bottom plate 102.
And a pair of support walls 104 extending substantially vertically from each other and facing each other, and a front wall 106 connecting these support walls 104. Outside the front wall 106, a paper feed tray 108 for storing a sheet (paper) S to be printed by the printer 100 is provided, and the sheet S stored in the paper feed tray 108 is provided.
Is supplied to the inside of the printer 100 via a paper feed port (not shown) formed in the front wall 106.

Inside the front wall 106, a pair of support walls 10
4, an upper guide rail 112 parallel to the front wall 106 and a lower guide rail 114 disposed below the upper guide rail 112 are supported. On these guide rails 112 and 114, an ink cartridge 116 is movably supported. Insert the ink cartridge 116 into the guide rails 112 and 114
The scanning mechanism 118 that reciprocates along a pair of the pulleys 120 supports a pair of pulleys 120 supported inside the front wall 106 near the respective support walls 104 and a belt 122 wound around these pulleys 120. And a motor (not shown) for rotating the pulley 120 forward and reverse.
The ink cartridge 116 is connected to a part of the second cartridge 2.

In the present embodiment, the ink cartridge 116 has one or a plurality of the above-described ink jet heads 1 on the lower surface thereof. Below the ink cartridge 116, a plate-like platen (sheet guide) 124 supported by a pair of side walls 123 is provided at a distance from the inkjet head 1. This sheet guide 12
4, a sheet feeding roller 128 that conveys the sheet S fed into the printer 100 through the sheet feeding port of the front wall 106 in the direction of arrow 126 (conveying direction).
Are arranged in a direction perpendicular to the paper feeding direction, and are rotatably supported by the opposing support wall 104.

Ink feed head 1 with respect to the paper feeding direction
An ink absorber 130 that adsorbs only the liquid solvent of the ink attached to the sheet S is rotatably supported by the shaft 131 and is disposed in the direction perpendicular to the sheet feeding direction in the vicinity of the sheet guide 124. Have been. Here, "proximity" means that the sheet S is placed on the sheet guide 124,
This means that the ink attached on the sheet S and the outer surface of the ink absorber 130 are at least close to contact. Note that a plurality of the absorbers 130 may be provided in the paper feeding direction.

As shown in FIG. 1B, the ink absorber 1
Reference numeral 30 denotes a roller or cylindrical base 130a (cylindrical in this embodiment), a polymer (liquid solvent) absorber 130b provided on the outer periphery of the base 130a and absorbing only the liquid solvent of the ink, Provided on the outer periphery of the body 130b,
And a porous release member 130c having releasability from the colorant. Here, the term “releasability” means that when the ink absorber 130 is brought into contact with the ink on the sheet S and then separated from the sheet S, the colorant of the ink adheres almost to the release member 130c. Means not to do.

The sheet S and the ink jet head 1
A pressing roller (not shown) for pressing the sheet S against the sheet guide 124 is provided on the downstream side of the ink absorber 130 with respect to the sheet feeding direction in order to keep a constant interval with the sheet guide.
Are arranged in a direction perpendicular to the sheet feeding direction.

The method for keeping the interval between the sheet S and the ink jet head 1 constant is not limited to this, and for example, an electrostatic method, an air suction method, or the like may be used instead. Specifically, the electrostatic type means at least the sheet guide 124
Is provided, and by charging the belt, the sheet S is conveyed while being attracted and held by the conveyance belt. On the other hand, in the air suction method, at least the sheet guide 124 is formed of a gas-permeable member (a mesh-like or porous member), and the sheet S is sucked from the lower side of the sheet guide 124 so that the sheet S is guided by the sheet guide. The paper is transported while being sucked and held on the paper 124 (in this case, the paper is transported by the paper feed roller 12
8 and a pressing roller, or may be performed by moving a mesh-like or porous belt that sucks and holds the sheet S along the sheet guide 124. ).

The paper feed roller 128 has a gear 134 fixed to a shaft 132 and a support wall 10 near the gear 134.
4 is connected to a motor 138 via a gear 136 rotatably supported by the motor 4, and the sheet feed roller 128 rotates based on the rotation of the motor 138 to convey the sheet S in the direction of arrow 126. It is.

When printing is performed by the printer 100 having the above-described configuration, the sheet S sent from the paper feed tray 108 is printed.
Is fed into the printer 100 through the paper feed port of the front wall 106. Next, the sheet S is conveyed in the direction of arrow 126 along the sheet guide 124 by the sheet feeding roller 128 that rotates based on the driving of the motor 138.

In synchronization with the movement of the sheet S, the ink cartridge 116 reciprocates along the guide rails 112 and 114 by the rotation of the belt 122, and
The ink is ejected from the ink jet head 1 to the portion of the sheet S that moves on the top 24, and printing is performed.

The printed sheet S is printed on the ink absorber 13
It moves to a position close to 0, and at this position, only the liquid solvent of the ink adhered on the sheet S is absorbed by the polymer absorber 130b via the release member 130c. Finally, the printed sheet S is discharged onto a discharge tray (not shown).

In order to efficiently absorb the solvent by the polymer absorber 130b, the ink absorber 130 is appropriately rotated, so that the polymer absorber that has not yet absorbed the solvent faces the sheet S. So that it is located in the area.

In the present embodiment, the ink absorber 13
0, the release member 130c is
b) (for example, a separate member type), but the surface of the polymer absorber 130b (the surface facing the sheet S) is made of a material having a releasability from the colorant. Surface treatment may be performed (that is, the same member type).

Next, the sheet S by the ink absorber 130 is used.
The mechanism for absorbing the liquid solvent in the above ink will be described in detail.

First, as described above, the ink that can be used in the present invention is an ink that can form a state in which a colorant and a liquid solvent are phase-separated on a sheet. Specifically, (1) Ink state (2) In the state of the ink, the colorant is dissolved in the solvent, but when the ink lands on the sheet, some color ink is applied on the sheet. The action causes the colorant to aggregate and, as a result,
Dye ink that can be separated from the solvent (in the case of FIGS. 3 to 5)
Is mentioned.

(1) Pigment ink After the pigment ink in which the pigment is dispersed in the solvent lands on the sheet S as shown in FIG. 2A, the sheet portion where the pigment ink lands is close to the ink absorber 130. Transported to a position where Therefore, as shown in FIG. 2B, the liquid solvent of the pigment ink is used as the release member 130c of the ink absorber 130.
Is absorbed into the polymer absorber 130b via the ink absorber 130, and penetrates into the sheet S under the pressure from the ink absorber 130. As a result, as shown in FIG.
Only the pigment remains on top.

(2) Dye Ink As shown in FIGS. 3 (a) and 3 (b), before the dye ink in which the dye is dissolved in the solvent lands on the sheet S, the dye is agglomerated and precipitated. An aggregation aid (for example, a quaternary amine or the like) is landed on the sheet (generally via an ink jet head like a dye ink). as a result,
The dye ink and the coagulation aid are mixed, and the dye is formed into particles as shown in FIG. Thereafter, as shown in FIG. 2, the ink absorber 130 absorbs the liquid other than the dye in which the ink is aggregated. It goes without saying that the coagulation aid may be landed after the dye ink has landed on the sheet S first.

Further, as shown in FIG. 4, the dye can be made into particles by discharging the dye ink onto the sheet S to which the coagulation aid has been applied in advance.

Further, as shown in FIG. 5, two types of anionic and cationic dye inks are superposed and adhered on the sheet S, whereby the dyes can be formed into particles. By using, for example, anionic acid red 8 and cationic basic red 12 as the dye contained in the ink, the above two types of dye inks can be obtained.

Although the first embodiment of the present invention has been described above, the present invention is not limited to this, and can be variously modified. For example, in the above embodiment, the ink absorber 130
Is disposed close to the plate-like platen 124, but is provided further downstream of the platen 124 and is brought into contact with another roller so that the sheet S passes between these rollers. You may.

Further, as shown in FIG.
30 is divided into a plurality of parts, and these ink absorber portions 130
a, 130b, and 130c may be arranged at different positions with respect to the transport direction 126 (in the case of the figure, a staggered arrangement). As a result, if some tired due to long-term use,
Only that part can be replaced.

Furthermore, the shape of the ink absorber 130 that absorbs only the solvent of the ink is a roller in the above embodiment, but the present invention is not limited to this. For example, as shown in FIG. 7A, the ink absorber 148 provided with a polymer absorber and a release member (both are denoted by reference numeral 152) on the outer periphery of the belt 150 may be used. Good. In the drawing, a roller 154 for suspending or driving the belt 150 (in the present embodiment, the roller 154 is used).
a, 154b, and 154c are provided, but the present invention is not limited to this. ) Is brought close to the sheet S, and only the solvent of the ink is absorbed by the polymer absorber 152 in this proximity area.
6 may be increased (that is, the belt portion along the sheet S is lengthened), thereby increasing the efficiency of ink absorption of the ink by the polymer absorber 152. Further, the belt 150 is rotated appropriately so that the portion of the polymer absorber that has not yet absorbed the solvent is located in a region facing the sheet S.

In addition, as shown in FIG. 7B, a stamp member 158 having a polymer absorber and a release member (both are indicated by reference numeral 156) at least on the side facing the sheet S is provided. The polymer absorber 156 is provided so as to be movable between a position close to the sheet S and a retracted position.
May absorb only the solvent of the ink.

In the following, materials used as ink materials, coagulation aids, polymer absorbers, and release members are listed.

A. Ink materials Pigment materials Pigments include azo, phthalocyanine, anthraquinone, quinacridone, dioxazine, indigo,
Thioindigo, perylene, aniline black, azomethine, rhodamine B lake, carbon black,
Alternatively, carbon black or the like having improved water dispersibility by surface modification can be used. Specifically, C.I. I. Pigment Yellow 1, 2, 3, 13, 16, 83, 93, 9
5, 151, 154, 180; I. Pigment Red 5, 7, 12, 48, 57, 112, 122;
I. Pigment Blue 1, 2, 3, 15: 3, 16 and the like are used.

With respect to the amount of the colorant to be added to the liquid solvent, if the amount is too small, the ink will not be given a sufficient color, while if the amount is too large, the dispersion of the colorant will occur. Is not sufficient, so that it is generally added in the range of 0.1 to 20% by weight (wt).

Dye materials Known water-soluble dyes such as acid dyes, direct dyes, reactive dyes, and oil-soluble dyes generally known in the art can be used. Examples of the above dyes include C.I. I. Acid Yellow 17, 23, 42, 44, 79, 14
2; I. Acid Red 1, 8, 13, 14, 1
8, 26, 27, 35, 37, 42, 52, 87, 8
9, 92, 97, 106, 111, 114, 115, 1
86, 249, 254, 289; I. Acid Blue 9, 29, 45, 92, 249; C.I. I. Acid Black 1, 2, 7, 24, 26, 94; C.I. I. Direct Yellow 1, 12, 24, 26, 33, 4
4, 50, 86, 120, 142, 144; I. Direct Red 1, 4, 9, 13, 17, 20, 28,
31, 39, 80, 81, 89, 225, 227;
I. Direct Blue 1,2,6,15,22,2
5, 71, 76, 79, 86, 87, 98, 163, 1
65, 199, 202; I. Direct black 19, 22, 32, 38, 51, 56, 71, 74,
C. 75, 77, 168, 171; I. Basic Yellow 1, 2, 11, 13, 14, 15, 19, 21,
23, 24, 28, 29, 32, 36, 40, 41, 4
5, 49, 53, 63, 64, 65, 67, 70, 7
3, 77, 87, 91; C.I. I. Basic red
2, 12, 13, 14, 15, 18, 22, 23, 2
4, 27, 35, 36, 38, 39, 46, 49, 5,
1, 52, 68, 68, 70, 73, 78, 82, 10
2, 104, 109, 112; I. Basic Blue 1, 3, 5, 7, 9, 21, 22, 26, 35, 4
1, 45, 54, 62, 65, 66, 67, 69, 7
5, 77, 89, 92, 93, 105, 117, 12
0, 122, 124, 129, 137, 141, 15
5; I. Basic Black 2, 8; C.I. I. Reactive Yellow 1, 5, 11, 13, 14, 20,
21, 22, 25, 40, 47, 51, 55, 65, 6
7; I. Reactive Red 1, 14, 17, 2
5, 26, 32, 37, 44, 46, 55, 66, 7
4, 79, 96, 97; I. Reactive blue
1, 2, 7, 14, 15, 23, 32, 35, 38, 4
1, 63, 80, 95; C.I. I. Reactive Black 3, 4, 7, 11, 12, 17 and the like can be used.

With respect to the amount of the colorant to be added to the liquid solvent, if the amount is too small, the ink will not be given a sufficient color, while if the amount is too large, the colorant will not be dispersed. Is not sufficient, so it is generally added in the range of 0.1 to 20 wt%.

Resins that may be added to ink A water-soluble or water-dispersible resin may be added for the purpose of improving the fixability of the aqueous ink or increasing the dispersibility of the pigment.

Examples of such a resin include hydroxyethyl cellulose, carboxymethyl cellulose,
Cellulose derivatives such as viscose, alginic acid, gum arabic, tragacanth gum, lignin sulfonic acid, natural polymers such as gelatin, starch derivatives such as starch phosphate, carboxymethyl starch, polyacrylic acid, polymethacrylic acid, polyvinyl sulfate, Polyvinyl sulfonic acid, condensed naphthalene sulfonic acid, ethylene-acrylic acid copolymer, styrene-acrylic acid copolymer, styrene
Methacrylic acid copolymer, acrylic acid ester-acrylic acid copolymer, acrylic acid ester, methacrylic acid copolymer, styrene-maleic acid copolymer, styrene-itaconic acid copolymer, itaconic acid ester-itaconic acid copolymer Copolymer, vinyl naphthalene-acrylic acid copolymer, vinyl naphthalene-methacrylic acid copolymer, vinyl naphthalene-
Itaconic acid copolymers and their copolymers, phenolic resins, polyamide resins, polyimide resins, polyamic acid resins, epoxy resins, polyester resins, polyurethane resins, polyurethane-urea resins, polyoxyethylene alkyl phenyl ether, polyoxyethylene Alkylamine, polyoxyethylene sorbitan fatty acid ester, polyvinyl alcohol, polyvinylpyrrolidone,
There are synthetic resins such as polyalkylene cations, phthalated gelatin, and polymers having zwitterionic groups.

Additives that may be added to control drying properties and prevent the deposition of colorants. In order to increase the drying properties of the ink and speed up the fixing of the ink to the recording medium, for example, methyl alcohol, ethyl alcohol, An aliphatic alcohol having 1 to 5 carbon atoms, such as n-propyl alcohol and isopropyl alcohol, preferably an aliphatic alcohol having 1 to 3 carbon atoms may be added. Ethylene glycol, diethylene glycol, glycerin,
Polyhydric alcohols or alkyl ethers thereof, or polar solvents such as dimethylformamide, dimethylacetamide, N-methyl-2-pyrrolidone, dimethylsulfoxide, amides, ureas or alkanolamines may be added. In addition, inorganic salts such as lithium bromide, sodium bromide, and sodium chloride having high hygroscopicity or high solubility in water, and organic salts such as sodium acetate, sodium toluenesulfonate, sodium phthalate, ammonium acetate, and triethanolamine acetate. May be added.

Others A fungicide, a preservative, a pH adjuster, a chelating agent, an oxygen absorber, a rust inhibitor or a quencher may be added.

B. Coagulation Aid Generally, a dye is anionic, and thus a cationic compound can be used as the coagulation aid. Examples of such compounds include polyallylamine-hydrochloride, tributylamine chloride, stearyltrimethylammonium salt, stearyltrimethylammonium chloride, copolymers of diallylamine hydrochloride and sulfur dioxide, and compounds such as polyaminesulfone.

C. Polymer Absorber The polymer absorber is not particularly limited as long as it is generally called a superabsorbent polymer composed of a polymer chain having a hydrophilic group.

The superabsorbent polymer is roughly classified into a crosslinked superabsorbent polymer in which the polymer chain has a three-dimensional network structure and a non-crosslinked superabsorbent polymer having no three-dimensional network structure. In the present invention, any of them may be used.

Specific examples of cross-linked superabsorbent polymers: polyacrylate cross-linked product; starch-polyacrylate; polyvinyl alcohol-polyacrylate; isobutylene-maleate; cross-linked CMC (carboxymethylcellulose); hydrophilic Crosslinked polyalkylene oxide / acrylic acid ester, or a mixture of two or more of these.

Specific examples of the non-crosslinked superabsorbent polymer: poly (meth) acrylic acid derivative-alkali metal polyacrylate-sodium (meth) acrylate-vinyl alcohol copolymer-methyl (meth) acrylate-acetic acid Saponified vinyl copolymer -Poly (meth) acrylonitrile-based polymer -Hydroxyethyl methacrylate polymer -Poly (meth) acrylamide ・ Carboxymethylcellulose alkali metal salt ・ Polyacrylamide ・ Sodium alginate ・ Propylene glycol alginate ・ Starch glycolic acid Sodium salt ・ Starch phosphate sodium salt ・ Starch-acrylate graft copolymer

Ancillary matters: The polymer absorber may be in the form of powder or fiber. It is preferable that the water absorption is 50 times or more so that the absorbed water does not seep out due to pressure or the like (there is no particular limitation because it is a balance with the process). The non-crosslinked type is preferably used as the polymer absorbent that absorbs water in a short time (it is not particularly limited because of a balance with the process). -In order to make the polymer absorbent easy to dry and reuse, it is preferable that the water absorption rate be 200 times or less (there is no particular limitation because it is a balance with the process).

Means for Applying to Structure When the polymer absorbent itself is difficult to use as a structure by itself (in a case where it is difficult to form a roller shape or belt shape because it is too fluffy and too dry), it can be used as a binder. The following various synthetic resins and rubbers can be used in combination.・ Polyvinyl ether type ・ Polyisobutylene type ・ SBR type ・ Butyl rubber type ・ Natural rubber type ・ Polyurethane type ・ Polyester type ・ Chloroprene type ・ Nitrile rubber type etc.

In the case where the binder is impermeable to moisture, the mixing ratio of the superabsorbent polymer layer is determined by
(Polymer absorber) :( Binder) = 20: 1 to 1: 2
It is preferably set to about 0.

D. Release Material of Separate Member Type As the release member for the separate member type, for example, a release film such as the following, release paper such as
Alternatively, a material obtained by combining these can be used.

Release Film A synthetic resin film coated with a fluorine-based or silicone-based release agent, or a synthetic resin film that has been subjected to a surface treatment such as fluororesin processing to provide release properties. Can be used. Examples of synthetic resin films that can be used include polyester such as polyethylene terephthalate, polyolefins such as polyethylene and polypropylene, cellulose derivatives such as cellulose triacetate and cellulose diacetate, and synthetic resin films such as polycarbonate, polyvinyl chloride, polyimide, and aromatic polyamide. it can.

Another release film PTFE resin film, FEP resin film, PFA resin film, CTFE resin film, ethylene tetrafluoride-ethylene copolymer, vinylidene fluoride resin film,
A fluorine-based synthetic resin film having releasability such as a vinyl fluoride resin film, or a synthetic resin film having relatively releasable properties such as a PE film, a PP film, and a TPX film.

Release paper: Polyolefin film-coated paper such as polyethylene or polypropylene, vinylidene chloride film-coated paper, paper coated with a release agent such as fluorine or silicone,
Etc. release paper.

Means for forming small holes in such a material include: a small hole shape is given to a mold at the time of molding by a casting method; molding is performed in a state where soluble particles are mixed in a resin material at the time of molding. , The soluble particles are dissolved and removed by immersing the formed film in a solvent. ・ The formed film is mechanically provided with small holes by pressing. ・ High frequency discharge and arc discharge in the formed film. In the case of release paper, a porous material itself can be used as the base paper, so that a coating material can be applied to the surface of the release paper. By adjusting the amount of coating, the target object can be obtained while keeping the pores of the substrate alive.

Here, the thickness of the release member is usually 5 to 5
It is 00 μm, preferably 10 to 200 μm. If the release member is too thin, the strength as a mechanical component cannot be maintained, or handling during the production of the release member will be poor. If the release member is too thick, the liquid absorbability from ink deteriorates and the adhesion to the printing surface deteriorates.

In some processes, gold, silver, nickel, or the like is used to prevent triboelectric charging of the release film.
Copper, palladium and alloys thereof, tin oxide, indium oxide, metal oxides such as zinc oxide, and a composition for an antistatic layer containing at least one conductive material selected from carbon black are dispersed in a film. You may. When dispersing such an antistatic layer composition in a film, for example, a ball mill, a roll mill, a kneader, an attritor, a double planetary mixer, a high-speed mixer, a high-speed stone mill, an agitator mill,
A sand mill, a pin mill, a pebble mill, a high-speed stirrer, an ultrasonic disperser, or the like can be used alone or in combination.

E. Release material of the same member type The release material for the same member type is a polymer absorber coated with a resin such as fluorine or silicone, or a polymer absorber coated with a fluorine or silicone interface. Those coated with an activator and those obtained by dry-treating a polymer material with a fluorine-based material can be used.

Resin Coating The resin is applied by brush coating, spatula coating, tampo coating, spray coating, hot spray coating, airless spray coating,
Known coating methods such as electrostatic coating, roller coating, curtain flow coating, flow coating, dip coating, electrodeposition coating, and ironing may be used, but tampo coating and spray coating are particularly suitable.

As the fluororesin to be applied, for example, PTFE resin, FEP resin, PFA resin, CTFE
Resin, fluorocarbon resin such as ethylene tetrafluoride-ethylene copolymer, vinylidene fluoride resin, vinyl fluoride resin, etc., was dispersed in a fine powder suspension mixed with a suitable binder resin or in a suitable solvent. It can be used in the form of an emulsion. Further, rubber materials such as fluoro rubber, tetrafluoroethylene propylene rubber, and fluoro thermoplastic elastomer can be used in the same manner.

As the silicone resin to be applied, for example, a crosslinked or vulcanized product such as a chain polymer or a branched polymer having a siloxane structure as a unit or a heat-cured silicone rubber may be used. Further, any of modified silicone resins such as dimethyl, methylvinyl, and methylphenylvinyl may be used. The resin may be any of a rigid body, an elastic body such as rubber, and a semi-solid such as gel. Elastic bodies containing silicone resins are also excellent.

When the total amount of the essential components in the water-repellent suspension composition is 100 wt%, the total content of the fluorine-based and / or silicone-based resin is 0.01 to 100% by weight.
Preferably, it is within the range of 3 wt%. The reason is,
If the amount is less than 0.01% by weight, a water-repellent suspension composition having excellent dispersion stability cannot be obtained, while if it exceeds 3% by weight, a surfactant is applied to the surface to be coated when the obtained water-repellent suspension composition is applied. This is due to the remaining paint remaining. Particularly preferably, it is in the range of 0.1 to 0.5 wt%.

Although a fluorine-based resin and / or a silicone-based resin has been exemplified as a particularly preferred release resin, a resin having a slightly lower release property can be used due to compatibility with the ink used in the process. In such a case, it goes without saying that other synthetic resins or natural resins can be used.

Application of Surfactant The method of applying the surfactant is the same as the application of the resin.

As the fluorine-based surfactant, any organic compound containing a fluorine atom and having a surface-active ability can be used. Examples of the fluorine-based surfactant include:-fluoroalkyl (C2-C10) carboxylic acid-disodium N-perfluorooctanesulfonylglutamate-3- [fluoroalkyl (C6-C11) oxy] -1-alkyl
Sodium-(C3-C4) sulfonate ・ Sodium 3- [ω-fluoroalkanoyl (C6-C8) -N-ethylamino] -1-propanesulfonate ・ N- [3- (Perfluorooctanesulfonamido) propyl] -N, N-dimethyl-N-carboxymethyleneammonium petaine ・ Fluoroalkyl (C11 to C20) carboxylic acid ・ Perfluoroalkyl (C7 to C13) carboxylic acid ・ Perfluorooctanesulfonic acid diethanolamide ・ Perfluoroalkyl (C4 to C12) sulfonate (Li,
K, Na) N-propyl-N- (2-hydroxyethyl) perfluorooctanesulfonamidePerfluoroalkyl (C6-C10) sulfonamidopropyltrimethylammonium saltPerfluoroalkyl (C6-C10) -N-ethyl Sulfonylglycine salt (K) bis (N-perfluorooctylsulfonyl-N-ethylaminoethyl) phosphate monoperfluoroalkyl (C6-C16) ethyl phosphate and the like.

The silicone-based surfactants used include: alkali salts of carboxy-modified silicone oil (Li, K, N
a) ・ Polyether-modified silicone oil.

The content of the fluorine-based and / or silicone-based surfactant is such that when the total amount of the essential components in the water-repellent emulsion composition is 100% by weight, the total amount of both is 0.01 to 5% by weight. It is preferably within the range. The reason is that if it is less than 0.01% by weight, a water-repellent emulsion composition having excellent dispersion stability cannot be obtained.
If the amount is more than wt%, the surfactant is left on the coated surface when the obtained water-repellent emulsion composition is applied, and the coating becomes uneven. Particularly preferably, 0.1 to 1 wt%
Within the range.

Although a fluorine-based and / or silicone-based surfactant has been exemplified as a particularly preferred surfactant here, it is possible to use a resin having a slightly low releasability due to compatibility with the ink used in the process. Needless to say, a surfactant other than these can be used when possible.

Dry processing Methods of dry processing include vapor deposition, plasma CVD, thermal CVD,
Conventional vacuum film formation methods such as photo-CVD, sputtering, reactive sputtering, ion plating, and cluster ion beam can be used. Starting materials in these vacuum film forming methods are solid and gas.

When the starting material for film formation is a solid, for example, a fluorine-based resin may be used as the material. When the starting material is a liquid or gas, a fluorine atom-containing gas may be used as a raw material. Further, even when the starting material is a solid or liquid, it can be used as a fluorine-based raw material that can be vaporized through melting, evaporation, sublimation, or the like by heating or reducing pressure.

As the above-mentioned fluororesin, for example, PT
FE resin, FEP resin, PFA resin, CTFE resin, ethylene tetrafluoride-ethylene copolymer, vinylidene fluoride resin, vinyl fluoride resin, and the like can be used.

Examples of the fluorine-based material that can be used as a gas include: 1) carbon tetrafluoride, ethyl fluoride, vinyl fluoride, propyl fluoride, methyl fluoride, tetrafluoroethylene, perfluoroethane, Fluorinated hydrocarbons such as perfluoropropane, 2) chlorodifluoromethane, 1-chloro-1,2,2-trifluoroethylene, 1-chloro-1-fluoroethylene, dichlorodifluoromethane, 1,1-difluoroethane, Gas containing fluorine atom such as tetrafluoroallene, trifluoroethylene, allyl fluoride, fluoroform, 1-bromo-1,2,2-trifluoroethylene, bromotrifluoroethane, etc. 3) Fluorine, hydrogen fluoride etc. An inorganic fluorine-based gas or the like can be used.

The above gases can be used alone or as a mixture. Further, depending on the film forming method, a solid and a gas can be used together as a starting material.

Further, the amount of fluorine atoms in the film after film formation is adjusted.
For the purpose of (mainly decreasing the concentration), a gas containing a carbon atom may be simultaneously deposited. As such a raw material gas containing carbon atoms, as a saturated hydrocarbon, for example, methane, ethane, propane, butane, pentane, hexane,
Heptane, octane, isobutane, isopentane, neopentane, isohexane, neohexane, dimethylbutane, methylhexane, ethylpentane, dimethylpentane, triptan, methylheptane, dimethylhexane,
Trimethylpentane, isononone, and the like are used. As unsaturated hydrocarbons, for example, ethylene, propylene, isobutylene, butene, pentene, methylbutene,
Hexene, tetramethylethylene, heptene, octene, allene, methylallene, butadiene, pentadiene, hexadiene, cyclopentadiene, ocimene, allocimene, myrcene, hexatriene, acetylene, diacetylene, methylacetylene, butyne, pentyne, hexine, heptin, octin Are used. Examples of the alicyclic hydrocarbon include, for example, cyclopropane, cyclobutane, cyclopentane, cyclohexane, cycloheptane, cyclooctane, cyclopropene, cyclobutene,
Cyclopentene, cyclohexene, cycloheptene, cyclooctene, limonene, terbinolene, ferrandrene, silvestrene, twene, karen, pinene, bornylene, camphene, fenchen, cyclofenchen, tricyclene, pisabolene, zingiberen, curcumen, humulene, kadinense sesquibeni Hen, Selinen,
Caryophyllene, Santarem, Sedren, Khanholen,
Filocladene, podocarprene, millen and the like are used. Examples of aromatic hydrocarbons include, for example, benzene, toluene, xylene, hemimelitene, pseudocumene, mesitylene, prenitene, isodurene, durene, pentamethylbenzene, hexamethylbenzene, ethylbenzene, propylbenzene, cumene, styrene, biphenyl, terphenyl, diphenylmethane , Triphenylmethane, dibenzyl, stilbene, indene, naphthalene, tetralin, anthracene, phenanthrene and the like.

For the purpose of diluting the source gas, a hydrogen gas, an argon gas, a helium gas or the like may be used in combination.

The film formation amount on the surface of the polymer absorber may be adjusted mainly by controlling the film formation time.

(Second Embodiment) An example in which the ink absorber according to the present invention is applied to a color ink jet printer is shown in FIG. In the present embodiment, an ink absorber 130 is provided between the ink jet heads 1Y (yellow), 1M (magenta), 1C (cyan), and 1K (black) for each color. As compared with the case where a drying unit for spraying is provided, the apparatus can be downsized even when the printing speed is high.

(Third Embodiment) FIG. 9 shows an example in which a mechanism for recovering the liquid solvent of the ink absorbed by the polymer absorber 130b of the ink absorber 130 is provided. In FIG. 9A, a cylindrical base 130a ′ supporting the polymer absorber 130b is provided with a cylindrical base 1 from the polymer absorber 130b.
A number of holes penetrate the base 130a 'to the inner surface of 30a'. A heater (not shown, for example, a lamp) or a ventilation device (not shown) is provided inside the base 130a ', so that the liquid solvent absorbed by the polymer absorber 130b can escape from the inside.

Alternatively, as shown in FIG. 9B, a housing 162 for closing at least a part of the outer surface of the ink absorber 130 is provided, and a heater or the like is provided in the housing 162, so that the ink absorbing body 130 is provided. The liquid solvent may escape from the outer surface of the body 130. However, in this case, since the liquid is allowed to escape using the holes in the solvent absorbing surface (the release member 130c), the efficiency of releasing the liquid is lower than in the configuration shown in FIG.

FIG. 10 shows a belt-shaped ink absorber 148.
An example is shown in which a mechanism is provided for recovering the liquid solvent of the ink absorbed by the polymer absorber 152 in the case where is used.
In the configuration shown in FIG. 10A, a mesh or porous belt 150 ′ is used, and the belt 150 ′ is used.
A heater (for example, a lamp or the like) or a ventilation device (not shown) is provided inside the
The liquid solvent absorbed in 52 is allowed to escape from the inside.

On the other hand, in the configuration shown in FIG. 10B, a housing 164 that closes at least a part of the outer surface of the ink absorber 148 is provided, and a heater or the like is provided in the housing 164, so that the ink absorber 148 is provided. The liquid solvent is allowed to escape from the outer surface of 148.

(Fourth Embodiment) FIG. 11 shows an example in which a squeezing mechanism for squeezing the liquid absorbed by the polymer absorber 152 of the belt-shaped ink absorber 148 is provided. In the present embodiment, a pair of squeezing rollers 166a and 166b are arranged with the ink absorber 148 interposed therebetween at a predetermined interval in a direction substantially orthogonal to the ink absorber 148. Below the lower squeezing roller 166a, a pair of squeezing rollers 166a,
Container 16 for receiving the liquid solvent squeezed out by 166b
8 are provided. The squeeze rollers 166a and 166b
Instead, a blade-shaped throttle member may be used.

The aperture mechanism may be activated when a predetermined number of sheets have been printed. In this case, the squeezing roller pair 16
6a and 166b are separated from the ink absorber 148, and are configured to come into contact with the ink absorber 148 for a predetermined time or for a predetermined number of sheets when the predetermined number has been reached.

Alternatively, the aperture mechanism may be activated when a predetermined number of ink droplets have been printed. In this case, the number of ink droplets may be obtained by counting the number of times the inkjet head 1 is driven.

Further, as shown in FIG.
Alternatively, a liquid amount sensor 170 for detecting the liquid amount in 2 may be provided, and the throttle mechanism may be operated when the sensor value reaches a predetermined amount. In this case, the liquid amount sensor 170 may use a method of detecting the liquid amount by measuring the electric conductivity between two points, or may use ultrasonic vibration to adjust the weight of the ink absorber 148 according to the weight. A method may be used in which a method of detecting the amount of liquid indirectly by obtaining a signal is used.

(Fifth Embodiment) FIG. 12 shows that after printing by the ink jet head, a polymer absorber is sprayed on the sheet S, and then the absorber absorbs the liquid solvent of the ink. The mechanism for removing the molecular absorber from the sheet S is shown.

This mechanism comprises an endless belt 170 having at least a portion facing the inkjet head 1 forming a horizontal plane 170a, rollers 172a, 172b, 172c for suspending and driving the belt 170, and a downstream side of the inkjet head 1. It has a spray port 174 facing the belt horizontal surface 170a and a polymer absorber spray device 176 having a storage unit 175 for storing the polymer absorber. The polymer absorber used in the present embodiment has a granular shape (for example, a particle size of 1 mm) surface-treated with a release material having a release property from a colorant.

The horizontal plane 170a of the belt 170 is formed by rollers 172a and 172b. In addition, by providing the roller 172c below the horizontal surface 170a, the slope 170 is provided between the roller 172b and the roller 172c.
b is formed. Opposite to the inclined surface 170b, a polymer absorber removing means, in this embodiment, a brush roller 178 composed of a central axis and a brush is provided rotatably around the central axis, and the brush of the brush roller 178 is attached to the inclined surface 170b.
To come into contact with. On the right side of the center axis of the brush roller 178, a striking rod 180
Is arranged. The sheet S passes through the horizontal surface 170a and the inclined surface 170b while being held on the belt 170, and is transferred to a sheet discharging mechanism (not shown).
The above-mentioned electrostatic method or air suction method is used as a means for holding the sheet on the belt 170.

The belt 17 is located on the opposite side of the roller 172b located at the right end of the horizontal plane 170a with the belt 170 interposed therebetween.
Another roller 182 is provided close to zero. As described later, the polymer absorber is pressed against the sheet S at a portion where the rollers 172b and 182 face each other, and absorbs the solvent of the ink that has landed on the sheet S.

Below the brush roller 178, a container 184 for collecting the polymer absorbent removed from the sheet S by the brush roller 178 is provided. Container 184
Inside, one end of the polymer absorber recovery pipe 186 is disposed. The other end of the collection tube 186 is the polymer absorber spraying device 1
A suction fan 188 that is connected to the storage section 175 and that suctions the polymer absorber from one end to the other end is provided in the middle of the storage section 175. In the middle of the recovery pipe 186,
A drying unit (not shown) such as a heater is provided to remove the liquid solvent from the polymer absorber.

Next, the operation of absorbing the liquid solvent of the ink on the sheet S in this embodiment will be described.

First, the belt 1 is driven by a paper feeding mechanism (not shown).
The sheet S conveyed on the horizontal plane 170a of 70 is printed in an area facing the inkjet head 1 [FIG.
2 (a)].

Next, the polymer absorber is sprayed on the sheet S through the spray port 175 of the polymer absorber spraying device 176 [FIG. 12 (b)]. In this state, the ink that has landed on the sheet S has not sufficiently absorbed the solvent.

Therefore, on the further downstream side, the rollers 18
By pushing the polymer absorbent toward the sheet S side by 2, the absorption of the ink solvent on the sheet S into the polymer absorbent is promoted [FIG. 12 (c)].

The sheet S is formed on the slope 170b of the belt 170.
Where the polymer absorber is removed from the surface by the rubbing force of the rotation of the brush roller 178.
Thereafter, the sheet S is delivered to a paper discharge mechanism (not shown).

The polymer absorber falls into the container 184 by the brush roller 178, and a part of the polymer absorber attached to the brush of the brush roller 178 also falls into the container 184 by the striker 180. The suction fan 188 is appropriately operated, and sends the polymer absorber in the container 184 to the storage unit 175 of the polymer absorber dispersion device 176 through the collection pipe 186.

(Experiments) The inventors of the present invention used the above-described various ink-jet printers according to the present invention using black ink under the following printing conditions, and ink-jet printers using no ink absorber as comparative examples. To print on the recording paper (these printers are Hewlett-Packard).
It was produced by modifying HP2000C manufactured by Ett Packard. ).

(Printing conditions) Ink: 51 manufactured by Hewlett Packard
645A ・ Nozzles of inkjet head: 304 nozzles,
Printing density 600 dpi (dot per inch), ink droplet volume about 3
0 picoliter, drive frequency 12kHz ・ Recording paper: EP paper manufactured by Minolta

The printed image was evaluated by the following two items, "drying" and "durability".

(Evaluation Items) Drying property After outputting (discharging) the entire solid image, another blank paper was gently overlapped on the recorded image, and a weight of 50 g / cm ² was gently placed thereon. The time required for the recorded image not to be transferred to the back side of the stacked white paper,
Evaluate as zero after output is completed. ○: less than 2 seconds ×: 2 seconds or more

Durability The dryness is evaluated immediately after 500 continuous solid images are printed.

Printing was performed using the following ink jet printer.

Example 1: Starch and sodium polyacrylate (both from Nacalai Tesque, Inc.)
10 parts by weight) and 1 part by weight of a commercially available rubber paste as a binder were added and uniformly mixed.
Processed into the shape of The thickness of the polymer absorber was 10 mm. The release material was a “separate member type”, and a commercially available PTFE resin film (thickness: 20 μm) having small holes (diameter 0.5 mm, density 200 / cm ² ) formed by press working was used. The inner surface of the PTFE resin film (on the side of the polymer absorber) and the inner surface of the pores were subjected to a plasma oxidation treatment for hydrophilicity.

Example 2 The release material was "the same member type" and the silicone resin TSR1 was used.
14 (manufactured by Toshiba Silicone Co., Ltd.) at a concentration of 0.1 wt% was spray-coated on the polymer absorber. Otherwise, the procedure was the same as in Example 1.

Example 3 Using the ink absorber shown in FIG. 9 (a), the inside of an aluminum cylindrical substrate was ventilated (warm air at 40 ° C., 5 l / sec). The cylindrical substrate has small holes having a diameter of 1 mm and a density of 50 holes / c.
It was drilled in m ^2. Otherwise, the procedure was the same as in Example 1.

Example 4 10 parts by weight of starch and sodium polyacrylate were mixed and homogenized, and granules having a diameter of 1 mm were used as a polymer absorber, and a silicone resin TSR1 was used.
14 was prepared so as to have a concentration of 0.1% by weight and applied. The surface-treated polymer absorber is shown in FIG.
2 was used. Drying by a heater (40 ° C. hot air heater) was performed in the middle of the collection pipe.

Comparative Example No ink absorber was used.

(Results) The results of the experiments are shown in the following table.

(Evaluation) As shown in the above table, the drying property
All are good except the comparative examples. Further, with respect to the durability, it can be seen that, although there is an absorption limit in Examples 1 and 2, it is more preferable to sequentially dry as in Examples 3 and 4.

[0108]

According to the image forming method of the present invention, a "ink in which a colorant is phase-separated in a liquid" such as a pigment ink or a dye ink phase-separated by agglutination.
In contrast, the liquid solvent can be removed while the colorant remains on the recording medium. As a result, it is possible to quickly dry the ink on the recording medium without lowering the image density, thereby preventing set-off.

Further, according to the present invention, the liquid solvent absorbed in the liquid solvent absorber may be gradually evaporated, or may be appropriately removed by heating, ventilation, etc., so that enormous power is consumed in a short time. The solvent can be effectively removed for a long period of time without replacing the liquid absorber.

The present invention can be applied to, for example, stains on fingers when a user holds a printed matter, ink stains on a recording medium reversing mechanism during double-sided printing, and ink stains on a post-processing mechanism such as a sorter or finisher after printing. In addition, it is possible to prevent various adverse effects due to ink drying.

[Brief description of the drawings]

FIG. 1 (a) is a perspective view of an ink jet printer using a cylindrical ink absorber according to the present invention. (B) Sectional drawing of an ink absorber.

FIG. 2 is a diagram illustrating a mechanism of absorbing a liquid solvent of ink on a sheet by an ink absorber when a pigment is used as a colorant of the ink.

FIG. 3 is a diagram showing a method for phase-separating a dye and a liquid solvent on a sheet when a dye is used as a coloring agent of the ink.

FIG. 4 is a diagram showing another method for phase-separating a dye and a liquid solvent on a sheet when a dye is used as a coloring agent of the ink.

FIG. 5 is a diagram showing still another method for phase-separating a dye and a liquid solvent on a sheet when a dye is used as a coloring agent of the ink.

FIG. 6 is a perspective view of an ink jet printer using another ink absorber.

FIG. 7A is a schematic view of an ink jet printer using a belt-shaped ink absorber. (B) Schematic diagram of an ink jet printer using a stamp-shaped ink absorber.

FIG. 8 is a schematic view showing an example in which the ink absorber according to the present invention is applied to a color inkjet printer.

FIG. 9A is a sectional view of another cylindrical ink absorber.
(B) A sectional view showing an example in which a mechanism for removing a liquid solvent from the outer surface of the ink absorber is provided.

10A is a schematic view of an ink jet printer using another belt-shaped ink absorber. FIG. (B) Schematic diagram of an ink jet printer provided with a mechanism for removing a liquid solvent from the outer surface of a belt-shaped ink absorber.

FIG. 11 is a schematic view showing another mechanism for removing a liquid solvent from a belt-shaped ink absorber.

FIG. 12 is a schematic diagram showing a configuration in which a polymer (liquid solvent) absorber is sprayed on ink on a sheet.

[Explanation of symbols]

1: inkjet head, 100: inkjet printer, 124: platen, 130: ink absorber, 1
30a: substrate, 130b: polymer (liquid solvent) absorber,
130c: Release member.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) B41J 3/04 101Y (72) Inventor Noboru 2-13-13 Azuchicho, Chuo-ku, Osaka-shi, Osaka Osaka International Building Minolta Co., Ltd. F-term (reference) 2C056 EA05 FC01 HA44 HA46 HA47 2H086 BA02 BA05 BA52 BA55 4G066 AC01B AC10D AC17B AE06B CA43 DA07 EA13 EA20

Claims (11)

[Claims] 1. A liquid solvent absorber for absorbing a liquid solvent of ink, and at least a part of a surface of the liquid solvent absorber, having a releasability from a colorant of the ink and permeating the liquid solvent of the ink. An ink absorber having a release member that performs the following. 2. An image forming apparatus for forming an image by depositing a liquid ink on a recording medium in accordance with image information, comprising: a liquid solvent absorber for absorbing a liquid solvent of the ink; A release member which covers at least a part of the ink and has a release property from a colorant of the ink and a release member permeable to a liquid solvent of the ink; Almost simultaneously or immediately thereafter, the liquid solvent absorber is brought close to the recording medium portion to which the ink is attached, with the release member interposed therebetween, whereby
An image forming apparatus, wherein a liquid solvent is absorbed by a liquid solvent absorber via a release member. 3. The image forming apparatus according to claim 2, wherein the liquid ink is in a state where a colorant and a liquid solvent are phase-separated at least on a recording medium. 4. The image forming apparatus according to claim 3, wherein said colorant is a pigment. 5. The image forming apparatus according to claim 3, wherein said colorant is a dye, and supplies an aggregating agent for aggregating the dye in the ink to the ink attached on the recording medium. 6. The image forming apparatus according to claim 2, further comprising a drying unit for drying the liquid solvent absorber. 7. An image forming method for forming an image by depositing a liquid ink on a recording medium in accordance with image information, wherein the ink is colored substantially simultaneously with or immediately after the ink is deposited on the recording medium. A liquid solvent absorber that absorbs the liquid solvent of the ink is brought close to the recording medium portion to which the ink is attached, with a release member having a releasing property from the agent and penetrating the liquid solvent of the ink sandwiched therebetween. An image forming method, wherein a liquid solvent is absorbed by a liquid solvent absorber through a release member. 8. The image forming method according to claim 7, wherein the liquid ink is in a state where a colorant and a liquid solvent are phase-separated at least on a recording medium. 9. An image forming method according to claim 8, wherein said colorant is a pigment. 10. The image according to claim 8, wherein the colorant is a dye, and the method further comprises a step of supplying a coagulation aid for coagulating the dye in the ink to the ink attached on the recording medium. Forming method. 11. The image forming method according to claim 7, further comprising a step of drying the liquid solvent absorber.