JP2000318300A - Method for ink jet recording - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance printing characteristic, image fixability and optical density irrespective of a type of a recording medium by adhering an ink containing a color material, a water soluble organic solvent and water to a recording medium containing a polymer substance for aggregating the material, and executing ink jet recording. SOLUTION: An ink containing a color material, a water soluble organic solvent and water is adhered to a recording medium containing a polymer substance having characteristics for aggregating the material, and ink jet recording is executed. As preferred embodiment of the substance, an acrylic polymer, an ester polymer, a urethane resin, an epoxy resin or the like is used. The ink contains, as indispensable components, the color material, the water soluble organic solvent and the water. As the material, a pigment, a dye or the like can be used. As a preferred embodiment of the solvent, an ethylene glycol, a diethylene glycol, a propylene glycol or the like is used. As preferred embodiments of the water, a pure water, an ultrapure water, ion-exchanged water or the like is used.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to an ink jet recording method.

[0002]

2. Description of the Related Art Liquid or molten solid ink is ejected from nozzles, slits or porous films, etc.
A so-called inkjet printer that records on a cloth, a film, and the like has various advantages such as small size, low cost, and quietness, and is often commercially available as a black or full-color printer. Above all, a so-called piezo ink-jet system using a piezoelectric element and a so-called thermal ink-jet system in which droplets are formed by applying thermal energy to perform recording have many advantages such as high-speed printing and high resolution. The water-soluble dye ink generally used in the ink jet recording system has excellent long-term storage stability, but has problems in water resistance and light resistance. On the other hand, inks using pigments have excellent water fastness and light fastness, and have high density and good image quality without bleeding, but have a problem in image fixability.

For this reason, various methods have been proposed as methods for improving the image fixability of pigment ink. For example, a method relating to a recording medium provided with an ink receiving layer composed of a water-soluble polymer or inorganic fine particles is disclosed in
It is disclosed in, for example, Japanese Patent Application Laid-Open No. 1-92886. But,
This method requires a dedicated recording medium, and cannot be applied to various recording media such as plain paper. Also,
A method for improving the fixability of a pigment ink by adding a water-soluble polymer to a recording medium is disclosed in JP-A-8-132729.
No. 6,009,045. However, in this method, a satisfactory image quality such as image blur cannot be obtained. As a method for improving the image fixing property of a pigment ink and improving the water resistance of a dye ink, an image forming method using a treatment liquid containing a cationic substance and a nonionic substance and an ink is disclosed in JP-A-8-193175. It has been disclosed. However, in this method, the image quality such as image bleeding and the image fixing property are simultaneously
I cannot be satisfied enough.

[0004]

SUMMARY OF THE INVENTION In order to solve the problems of the prior art, the present invention has excellent printing characteristics such as image bleeding regardless of the type of recording medium such as plain paper.
Good image fixability, high optical density, and
An object of the present invention is to provide an ink jet recording method for preventing strikethrough.

[0005]

Means for Solving the Problems As a result of intensive studies, the present inventors have developed an ink jet recording method for attaching an ink containing a coloring material, a water-soluble organic solvent and water to a recording medium containing a polymer substance. The present inventors have found that the above object can be achieved by an ink jet recording method in which the polymer substance causes the coloring material to aggregate, and the present invention has been completed.

That is, the present invention relates to an ink jet recording method for adhering an ink containing a coloring material, a water-soluble organic solvent and water to a recording medium containing a polymer substance.
An ink-jet recording method, wherein the polymer substance aggregates the coloring material; an ink-jet recording method, wherein the recording medium contains an electrolyte; a treating agent containing the polymer substance, And a step of attaching an ink containing a coloring material, a water-soluble organic solvent and water to a recording medium, wherein the polymer substance causes the coloring material to aggregate. Ink jet recording method. The inkjet recording method, wherein the treatment agent contains an electrolyte; the number of coarse particles of 0.5 μm or more in 1 liter of a mixture of the treatment agent and the ink is 1 × 10 ¹¹ or more. And the number of coarse particles of 5 μm or more is 1 ×
The ink jet recording method is characterized in that 10 ⁹ or more; the viscosity of the ink, 1.5～6.0MP
the inkjet recording method, wherein the colorant is a pigment; and the number average particle diameter of dispersed particles in the ink is 15 to 100 nm; And the ink-jet recording method, wherein the volume average particle diameter is 30 to 200 nm;

The ink-jet recording method, wherein the pigment is dispersed by a polymer dispersant;
The inkjet recording method, wherein the polymer dispersant comprises a copolymer of a hydrophilic part and a hydrophobic part;
The inkjet recording method, wherein the monomer constituting the hydrophilic portion of the polymer dispersant is at least one selected from the group consisting of acrylic acid, methacrylic acid and (anhydride) maleic acid; Wherein said monomer constituting the hydrophobic part of the polymer dispersant is at least one selected from the group consisting of styrene, alkyl, aryl and alkylaryl esters of (meth) acrylic acid. Method;

The ink-jet recording method, wherein the pigment is a self-dispersible pigment in water; the ink-jet recording method, wherein the coloring material is a dye; An ink jet recording method comprising a cyan ink, a magenta ink, and a yellow ink, and a coloring material of the ink being a pigment; wherein the ink is at least a black ink, a cyan ink, a magenta ink, and a yellow ink; The inkjet recording method, wherein the color material of the black ink is a pigment; and the inkjet recording method, wherein the polymer substance is a urethane resin or an ether-based polymer; After the step of applying a treating agent, the ink A and the ink jet recording method of the ink, characterized in that deposited by thermal ink jet recording system; the inkjet recording method and performing adhering step.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail. As the polymer substance used in the present invention,
For example, acrylic polymers, ester polymers, urethane resins, epoxy resins, UV / EB resins, ether polymers and the like can be mentioned. Preferred high molecular substances include a reaction product of a polyol having an alkylene oxide chain, a polycarbonate chain or a polyester chain and a polyisocyanate. Examples of the polyol having an alkylene oxide chain include those obtained by adding an alkylene oxide to polyhydric alcohols. Examples of polyhydric alcohols include ethanediol, propanediol, butanediol, hexanediol, glycerin, trimethylolpropane, and pentaerythritol. Examples of the alkylene oxide chain include ethylene oxide, propylene oxide, butylene oxide and the like. More specifically, as the polyol having an alkylene oxide chain, for example, polyoxyethylene glycol, polyoxypropylene glycol, polyoxyethylene-polyoxypropylene copolymer glycol, polyoxyethylene-polyoxybutylene copolymer glycol And the like. Examples of the polyol having a polycarbonate chain include a reaction product obtained by reacting a glycol such as diethylene glycol with diphenyl carbonate or phosgene. Examples of the polyol having a polyester chain include a polyester obtained by reacting diethylene glycol with a carboxylic acid.

On the other hand, examples of the polyisocyanate include diisocyanates such as ethylene diisocyanate, butylene diisocyanate, hexylene diisocyanate, phenylene diisocyanate, naphthylene diisocyanate, diphenylmethane diisocyanate, and tolylene diisocyanate. Mixtures can also be used. Particularly, a urethane resin having an alkylene oxide chain or an ether-based polymer is preferable. It is presumed that these compounds have a large effect of improving printing characteristics such as image bleeding since the coloring material has a large cohesive property.

The ink used in the present invention contains a coloring material, a water-soluble organic solvent and water as essential components. As the coloring material, pigments, dyes, and the like can be used. As the pigment, any of an organic pigment and an inorganic pigment can be used, and as the black pigment, furnace black,
And carbon black pigments such as lamp black, acetylene black, and channel black. Also,
In addition to the three primary color pigments of black and cyan, magenta, and yellow, specific color pigments such as red, green, blue, brown, and white, metallic luster pigments such as gold and silver, colorless or light color extender pigments, and plastic pigments May be used. In addition, a newly synthesized pigment may be used for implementing the present invention.

Specific examples of black pigments include Raven
7000, Raven 5750, Raven 5250,
Raven 5000 ULTRAII, Raven 350
0, Raven2000, Raven1500, Rav
en1250, Raven1200, Raven119
0 ULTRAII, Raven1170, Raven1
255, Raven1080, Raven1060 (all manufactured by Columbian Carbon Co., Ltd.), Regal400
R, Regal330R, Regal660R, Mog
ul L, Black Pearls L, Monarc
h 700, Monarch 800, Monarch
880, Monarch 900, Monarch 10
00, Monarch 1100, Monarch 13
00, Monarch 1400 (all manufactured by Cabot Corporation), Color Black FW1, Color B
black FW2V, Color Black FW2V,
Color Black 18, Color Black
FW200, Color Black S150, Col
or Black S160, Color BlackS
170, Printex35, Printex U, P
Printex V, Printex 140U, Prin
tex140V, Special Black6, Sp
electrical Black 5, Special Black
k4A, Special Black 4 (above, manufactured by Degussa), No. 25, no. 33, no. 40, N
o. 47, no. 52, no. 900, No. 230
0, MCF-88, MA600, MA7, MA8, MA
100 (all manufactured by Mitsubishi Chemical Corporation) and the like, but are not limited thereto.

Cyan pigments include CI Pigm.
ent Blue-1, CI Pigment Blue
-2, C.I.Pigment Blue-3, C.I.P.
iigment Blue-15, C.I.Pigment
Blue-15: 1, CI Pigment Blue
-15: 3, CI Pigment Blue-15:
34, C.I.Pigment Blue-16, C.I.
Pigment Blue-22, C.I.Pigmen
t Blue-60 and the like, but are not limited thereto.

[0014] Examples of magenta pigments include CI Pig.
ment Red-5, CI Pigment Red-
7, CI Pigment Red-12, CI Pi
gment Red-48, CI Pigment Re
d-48: 1, CI Pigment Red-57,
CI Pigment Red-112, CI Pig
Ment Red-122, CI Pigment Re
d-123, CI Pigment Red-146,
CI Pigment Red-168, CI Pig
Ment Red-184, CI Pigment Re
d-202 and the like, but are not limited thereto.

Examples of the yellow pigment include CI Pigmen.
t Yellow-1, CI Pigment Yellow
ow-2, CI Pigment Yellow-3,
C.I.Pigment Yellow-12, C.I.P.
iigment Yellow-13, C.I.Pigme
nt Yellow-14, CI Pigment Ye
llow-16, C.I.Pigment Yellow
-17, CI Pigment Yellow-73,
C.I.Pigment Yellow-74, C.I.P.
iigment Yellow-75, C.I.Pigme
nt Yellow-83, CI Pigment Ye
llow-93, C.I.Pigment Yellow
-95, C.I.Pigment Yellow-97,
C.I.Pigment Yellow-98, C.I.P.
iigment Yellow-114, C.I.Pigm
ent Yellow-128, CI Pigment
Yellow-129, CI Pigment Yellow
low-151, C.I.Pigment Yellow
-154 and the like, but are not limited thereto.

In the present invention, a pigment which can be self-dispersed in water can be used as the pigment. The pigment that is self-dispersible in water is a pigment that has many water-solubilizing groups on the surface of the pigment and is stably dispersed without the presence of a polymer dispersant. Specifically, by subjecting ordinary so-called pigments to a surface modification treatment such as an acid / base treatment, a coupling agent treatment, a polymer graft treatment, a plasma treatment, and an oxidation / reduction treatment, the pigment is self-dispersed in water. Possible pigments are obtained.

In order for the pigment to be self-dispersible in water in the present invention, the amount of change in pigment concentration when the pigment dispersion is left for one day must be 2% or less. That is, the concentration was adjusted to 95% by weight of water / 5% by weight of pigment, the pigment was dispersed using an ultrasonic homogenizer, and the pigment concentration of the resulting dispersion was measured immediately after dispersion and after standing at room temperature for one day. The criterion for a self-dispersible pigment is that the density after standing is 98% or more of the initial density.

Further, as pigments which can be self-dispersed in water,
In addition to the pigment obtained by subjecting the pigment to a surface modification treatment, Cab-o-jet-200 and Cab-o manufactured by Cabot Corporation
-Jet-300, IJX-55, Microjet Black CW-1 manufactured by Orient Chemical Co., and a commercially available pigment such as a pigment sold by Nippon Shokubai can also be used.

The solubilizing group present on the surface of the pigment that is self-dispersible in water can be any of nonionic, cationic and anionic ones, but is preferably sulfonic acid, carboxylic acid, hydroxyl group or phosphoric acid. The solubilizing group is sulfonic acid,
In the case of carboxylic acid or phosphoric acid, it can be used as it is as a free acid, but it is preferable to use it as a salt with a basic compound in order to enhance water solubility.
Compounds that form salts with these polymers include alkali metals such as sodium, potassium and lithium, aliphatic amines such as monomethylamine, dimethylamine and triethylamine, monomethanolamine, monoethanolamine, diethanolamine and triethanol. Amine,
Alcohol amines such as diisopropanolamine, ammonia and the like can be used. Among these,
Preferably, a basic compound of an alkali metal such as sodium, potassium and lithium is used. This is presumably because the basic compound of the alkali metal is a strong electrolyte and has a large effect of promoting the dissociation of the acidic group.

On the other hand, the dye which can be used in the present invention may be any of a water-soluble dye, an oil-based dye and a disperse dye. In particular, a dye which easily precipitates is preferable since the effects of the present invention can be effectively obtained. Specific examples of the water-soluble dye include CI Direct Black-2 and-.
4, -9, -11, -17, -19, -22, -32,
-80, -151, -154, -168, -171,-
194, -195, CI Direct Blue-1,-
2, -6, -8, -22, -34, -70, -71,-
76, -78, -86, -112, -142, -16
5, -199, -200, -201, -202, -20
3, -207, -218, -236, -287, -30
7, CI Direct Red-1, -2, -4, -8,
-9, -11, -13, -15, -20, -28, -3
1, -33, -37, -39, -51, -59, -6
2, -63, -73, -75, -80, -81, -8
3, -87, -90, -94, -95, -99, -10
1, -110, -189, -227, CI Direct Yellow-1, -2, -4, -8, -11, -12,-
26, -27, -28, -33, -34, -41, -4
4, -48, -58, -86, -87, -88, -13
2, -135, -142, -144, -173, C.I.
Food Black-1, -2, CI Acid Black-
1, -2, -7, -16, -24, -26, -28,-
31, -48, -52, -63, -107, -112,
-118, -119, -121, -156, -172,
-194, -208, CI Acid Blue-1,-
7, -9, -15, -22, -23, -27, -29,
-40, -43, -55, -59, -62, -78,-
80, -81, -83, -90, -102, -104,
-111, -185, -249, -254, CI Acid Red-1, -4, -8, -13, -14, -1
5, -18, -21, -26, -35, -37, -5
2, -110, -144, -180, -249, -25
7, CI Acid Yellow-1, -3, -4, -7,-
11, -12, -13, -14, -18, -19, -2
3, -25, -34, -38, -41, -42, -4
4, -53, -55, -61, -71, -76, -7
8, -79, -122 and the like.

The coloring material used in the ink of the present invention may be used alone or in combination of two or more. The content of the coloring material in the ink is based on the weight of the ink.
It is preferably 0.5 to 20% by weight, more preferably 1 to 10% by weight. 0.5% by weight of color material
When the amount is less than the above, a sufficient optical density may not be obtained, and when the amount of the coloring material is more than 20% by weight, clogging may be deteriorated.

The organic solvent which is an essential component in the ink of the present invention includes ethylene glycol, diethylene glycol, propylene glycol, butylene glycol, triethylene glycol, 1,5-pentanediol, 1,
Polyhydric alcohols such as 2,6-hexanetriol and glycerin, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, propylene glycol monobutyl ether, Polyhydric alcohol derivatives such as propylene glycol monobutyl ether and ethylene oxide adduct of diglycerin, nitrogen-containing solvents such as pyrrolidone, N-methyl-2-pyrrolidone, cyclohexylpyrrolidone and triethanolamine, ethanol, isopropyl alcohol, butyl alcohol and benzyl Alcohols such as alcohol, thiodiethanol, thiodiethanol Riseroru, sulfolane, sulfur-containing solvents such as dimethyl sulfoxide, propylene carbonate, may be used ethylene carbonate.

The water-soluble organic solvent may be used alone,
More than one kind may be mixed and used. The content of the water-soluble organic solvent is preferably from 1 to 60% by weight, more preferably from 5 to 40% by weight, based on the weight of the ink. If the content is less than 1% by weight, the long-term storage stability may decrease, and if it exceeds 60% by weight, the ink ejection properties may decrease.

As the water which is an essential component of the ink of the present invention, pure water, ultrapure water, ion-exchanged water and the like can be used.

The ink of the present invention may also contain a polymer dispersant for dispersing a pigment or a disperse dye. As the polymer dispersant, a compound having a hydrophilic structure portion and a hydrophobic structure portion can be effectively used, and specific examples thereof include a condensation polymer and an addition polymer. Examples of the condensation polymer include known polyester polymers, and examples of the addition polymer include an addition polymer of a monomer having an α, β-ethylenically unsaturated group.
More specifically, as the addition polymer, a copolymer in which a monomer having an α, β-ethylenically unsaturated group having a hydrophilic group and a monomer having an α, β-ethylenically unsaturated group having a hydrophobic group are appropriately combined is used. A polymer or the like is used. Further, a homopolymer of a monomer having an α, β-ethylenically unsaturated group having a hydrophilic group may be used.

Examples of the monomer having an α, β-ethylenically unsaturated group having a hydrophilic group include monomers having a carboxyl group, a sulfonic acid group, a hydroxyl group, a phosphoric acid group and the like, for example, acrylic acid, methacrylic acid, crotonic acid, Itaconic acid, itaconic acid monoester, maleic acid, maleic acid monoester, fumaric acid, fumaric acid monoester, vinyl sulfonic acid, styrene sulfonic acid, sulfonated vinyl naphthalene, vinyl alcohol, acrylamide, methacryloxyethyl phosphate, bismethacryloxy Ethyl phosphate, methacryloxyethyl phenyl acid phosphate, ethylene glycol dimethacrylate, diethylene glycol dimethacrylate and the like can be used.

On the other hand, monomers having an α, β-ethylenically unsaturated group having a hydrophobic group include styrene derivatives such as styrene, α-methylstyrene and vinyltoluene, vinylcyclohexane, vinylnaphthalene, vinylnaphthalene derivatives, acrylic acid Alkyl esters, phenyl acrylate, alkyl methacrylate, phenyl methacrylate, cycloalkyl methacrylate, alkyl crotonate, dialkyl itaconate, and dialkyl maleate can be used.

The copolymer obtained by copolymerizing the above-mentioned monomer having a hydrophilic group and a hydrophobic group may have any structure such as random, block and graft copolymers. These copolymers may be appropriately copolymerized with a monomer having a polyoxyethylene group and a hydroxyl group. Further, in order to increase affinity with a pigment having an acidic functional group on the surface and improve dispersion stability, a monomer having a cationic functional group, for example, N, N-dimethylaminoethyl methacrylate, N, N-dimethyl Aminoethyl acrylate, N, N-dimethylaminomethacrylamide, N, N-dimethylaminoacrylamide, N-
Vinylpyrrole, N-vinylpyridine, N-vinylpyrrolidone, N-vinylimidazole and the like may be appropriately copolymerized.

In this case, examples of preferred copolymers include styrene-styrene sulfonic acid copolymer, styrene-maleic acid copolymer, styrene-methacrylic acid copolymer, styrene-acrylic acid copolymer, and vinyl naphthalene. -Maleic acid copolymer, vinyl naphthalene-methacrylic acid copolymer, vinyl naphthalene-acrylic acid copolymer,
Acrylic acid alkyl ester-acrylic acid copolymer, methacrylic acid alkyl ester-methacrylic acid, styrene-methacrylic acid alkyl ester-methacrylic acid copolymer, styrene-acrylic acid alkyl ester-acrylic acid copolymer, styrene-phenyl methacrylate Ester-methacrylic acid copolymer, styrene-cyclohexyl methacrylate-methacrylic acid copolymer and the like can be mentioned.

Although not particularly limited, the hydrophilic group of the polymer dispersant is preferably a carboxylic acid or a salt of a carboxylic acid. It is considered that this is because when a carboxylic acid is used for the hydrophilic group, the pigment is appropriately aggregated on paper. Among these polymer dispersants, the copolymer having a hydrophilic group as an acidic group is preferably used in the form of a salt with a basic compound in order to enhance water solubility. Compounds which form salts with these copolymers include alkali metals such as sodium, potassium and lithium, aliphatic amines such as monomethylamine, dimethylamine and triethylamine, monomethanolamine, monoethanolamine, diethanolamine and triethanol. Amine, alcohol amines such as diisopropanolamine, ammonia and the like can be used. Preferably, a basic compound of an alkali metal such as sodium, potassium and lithium is used. This is because alkali metals are strong electrolytes,
It is considered that this has the effect of promoting the dissociation of the hydrophilic group.

The amount of neutralization of the polymer dispersant is preferably 50% or more of the acid value of the copolymer, more preferably 80% or more of the acid value of the copolymer. Is more preferable. The molecular weight of the polymer dispersant is preferably from 2,000 to 15,000 in terms of weight average molecular weight, and more preferably from 3,500 to 10,000 in terms of weight average molecular weight. As for the structure and the composition ratio of the hydrophobic part and the hydrophilic part, preferable ones can be used from the combination of the pigment and the solvent.

These polymer dispersants may be used alone or in combination of two or more. The amount of the polymer dispersing agent varies greatly depending on the pigment and cannot be unconditionally determined.
0% by weight, preferably 1 to 70% by weight, more preferably 3 to 50% by weight.

The ink of the present invention comprises, as other components,
In order to control ink properties, surfactants, polyethyleneimines, polyamines, cellulose derivatives such as polyvinylpyrrolidone, polyethylene glycol, ethylcellulose, carboxymethylcellulose, polysaccharides and derivatives thereof, other water-soluble polymers, acrylic polymer emulsions, and polyurethanes Polymer emulsions such as emulsions, cyclodextrins, macrocyclic amines, dendrimers, crown ethers, urea and its derivatives,
Acetamide and the like can be contained. Further, in order to adjust the conductivity and pH, compounds of alkali metals such as potassium hydroxide, sodium hydroxide, and lithium hydroxide, ammonium hydroxide, triethanolamine, diethanolamine, ethanolamine, and 2-amino-2-
Nitrogen-containing compounds such as methyl-1-propanol, compounds of alkaline earth metals such as calcium hydroxide, acids such as sulfuric acid, hydrochloric acid and nitric acid, and salts of strong acids and weak alkalis such as ammonium sulfate can be used. Further, in the ink of the present invention, if necessary, a pH buffering agent, an antioxidant, a fungicide, a viscosity modifier, a conductive agent, an ultraviolet absorber, a chelating agent, a disperse dye, a dye for oil, and the like are also included. Can be added.

In the present invention, the viscosity of the ink is 1.5 to 1.5.
6.0 mPa · s is preferable, and 1.5 to 4.0 mPa · s is preferable.
s is more preferred. When the viscosity of the ink is larger than 6.0 mPa · s, the ejection characteristics become unstable. On the other hand, when the viscosity of the ink is smaller than 1.5 mPa · s, the long-term storage stability may be poor. Note that, in the present invention, the viscosity of the ink is determined by using Rheomat 115 (Contra
ves). The measurement method was ink 1
0 ml was placed in a measurement container, and the measurement was carried out at a measurement temperature of 23 ° C. and a shear rate of 1400 s ⁻¹ according to a predetermined method.

The pH of the ink in the present invention is 3 to 11
Is preferred, and 4.5 to 9.5 is more preferred. In particular, when the ink is an anionic ink, the pH is 6 to 11
Is preferable, 6 to 9.5 is more preferable, and pH is 7.5.
-9.0 is more preferable. On the other hand, when the ink is a cationic ink, the pH is preferably from 4.5 to 8.0, more preferably from 4.5 to 7.0.

In the present invention, the conductivity of the ink is 0.0
The range of 1 to 0.5 S / m is preferable, and 0.05 to 0.2 S / m.
The range of S / m is more preferable. Conductivity is 0.01 S / m
Below and above 0.5 S / m,
Long-term storage stability may decrease. In the present invention, the conductivity of the ink is measured by a conductivity meter AOL-40-3.
302 (manufactured by DKK). The measurement method is
50 ml of the ink was placed in a measurement container, the measurement probe was immersed, and the measurement was performed according to a predetermined method.

The surface tension of the ink in the present invention is 15
It is preferably at least mN / m. When the surface tension of the ink was less than 15 mN / m, the ejection of the ink was sometimes unstable.

The treating agent in the present invention preferably contains the above-mentioned polymer substance in an amount of 0.1 to 50% by weight, more preferably 0.5 to 20% by weight, based on the treating agent. When the content of the polymer substance is less than 0.1% by weight, the printing characteristics may be reduced, and when it exceeds 50% by weight, the long-term storage stability may be reduced.

The treating agent in the present invention preferably contains an electrolyte. Examples of the electrolyte include alkali metals such as lithium, sodium, and potassium, and polyvalent metals such as aluminum, barium, calcium, copper, iron, magnesium, manganese, nickel, tin, titanium, and zinc; hydrochloric acid, bromic acid, and hydrogen iodide. Acids, sulfuric acid, nitric acid, phosphoric acid, thiocyanic acid, acetic acid, oxalic acid, lactic acid, fumaric acid, fumaric acid, citric acid, salicylic acid, salts with organic carboxylic acids such as benzoic acid, and the like, and the like. It is also possible to use a cationic substance which becomes an organic cation by dissociation in water.
And quaternary amines and their salts.

Specific examples of the electrolyte include lithium chloride,
Salts of alkali metals such as sodium chloride, potassium chloride, sodium bromide, potassium bromide, sodium iodide, potassium iodide, sodium sulfate, potassium nitrate, sodium acetate, potassium oxalate, sodium citrate, potassium benzoate, and chlorides Aluminum, aluminum bromide, aluminum sulfate, aluminum nitrate, sodium aluminum sulfate, potassium aluminum sulfate, aluminum acetate, barium chloride, barium bromide, barium iodide, barium oxide, barium nitrate, barium thionate, calcium chloride, calcium bromide , Calcium iodide, calcium nitrite, calcium nitrate, calcium dihydrogen phosphate, calcium thiocyanate, calcium benzoate, calcium acetate, calcium salicylate, calcium tartrate, lactate Siumu, calcium fumarate, calcium citrate, copper chloride, copper bromide, copper sulfate, copper nitrate,
Copper acetate, iron chloride, iron bromide, iron iodide, iron sulfate, iron nitrate,
Iron oxalate, iron lactate, iron fumarate, iron citrate, magnesium chloride, magnesium bromide, magnesium iodide, magnesium sulfate, magnesium nitrate, magnesium acetate,
Magnesium lactate, manganese chloride, manganese sulfate, manganese nitrate, manganese dihydrogen phosphate, manganese acetate, manganese salicylate, manganese benzoate, manganese lactate, nickel chloride, nickel bromide, nickel sulfate, nickel nitrate, nickel acetate, nickel acetate, tin sulfate, Titanium chloride, zinc chloride,
Examples include salts of polyvalent metals such as zinc bromide, zinc sulfate, zinc nitrate, zinc thiocyanate, and zinc acetate.

On the other hand, examples of the cationic substance include tetraalkylammonium salts, alkylamine salts, benzalkonium salts, alkylpyridium salts, imidazolium salts,
And polyamines. Further, specific examples thereof include isopropylamine, isobutylamine, t-butylamine, 2-ethylhexylamine, nonylamine,
Dipropylamine, diethylamine, trimethylamine, triethylamine, dimethylpropylamine, ethylenediamine, propylenediamine, hexamethylenediamine, diethylenetriamine, tetraethylenepentamine, diethanolamine, diethylethanolamine, triethanolamine, tetramethylammonium chloride, tetraethylammonium bromide, dihydroxy Ethyl stearylamine, 2-heptadecenyl-hydroxyethylimidazoline, lauryldimethylbenzylammonium chloride, cetylpyridinium chloride, stearamidomethylpyridium chloride, diallyldimethylammonium chloride polymer,
Diallylamine polymers, monoallylamine polymers and the like.

Among these, preferred electrolytes are aluminum sulfate, calcium chloride, calcium nitrate, calcium acetate, magnesium chloride, magnesium nitrate,
Magnesium sulfate, magnesium acetate, tin sulfate, zinc chloride, zinc nitrate, zinc sulfate, zinc acetate, aluminum nitrate, monoallylamine polymer, diallylamine polymer,
Diallyldimethylammonium chloride polymer and the like. The content of the electrolyte in the treatment agent of the present invention is preferably 0 to 25% by weight, more preferably 0.5 to 10% by weight, based on the treatment agent. When the content of the electrolyte exceeds 25% by weight, long-term storage stability may be reduced. The treating agent of the present invention can further contain a surfactant or a water-soluble organic solvent as needed.

The apparatus for printing with the ink in the present invention is not particularly limited, and includes not only ordinary ink jet recording apparatuses such as thermal ink jet recording apparatuses and piezo ink jet recording apparatuses but also heaters for controlling ink drying. It is possible to use a recording device or the like which mounts a recording device and an intermediate transfer mechanism, prints a recording material on the intermediate, and then transfers the recording material to a recording medium such as paper. Further, the treatment agent in the present invention is applied to a recording medium by a method such as an ink jet recording method, a brush coating method, a flow coating method, a roller coating method, a spray coating method, a dip coating method, an electrostatic coating method, and adhered thereto. be able to. The treatment agent may be applied to the entire recording medium or only to the printed portion.

The ink jet recording method of the present invention includes a step of attaching a treating agent containing a polymer substance to a recording medium, and a step of attaching an ink containing a coloring material, a water-soluble organic solvent and water to the recording medium. . Either of these two steps may be performed first, but it is preferable that the step of attaching a treatment material containing a polymer substance to a recording medium is performed first. Further, the ink of the present invention can be printed by an ink jet recording method on a recording medium in which the polymer substance of the present invention is contained in advance.

The ink jet recording method of the present invention can achieve the effects of the present invention regardless of the type of recording medium. Accordingly, any recording medium such as a film such as plain paper, glossy paper, coated paper, and OHP sheet paper can be used.

(Function) The polymer substance used in the present invention is considered to have the following two functions. 1) Aggregating the coloring material. 2) Fixing the coloring material by the binder effect. This mechanism is assumed as follows. 1) Due to the colorant aggregating effect of the polymer substance, the penetration of the colorant into the paper is suppressed, so that image bleeding is improved and the optical density is increased. 2) Due to the binder effect, the coloring material is fixed on or near the paper surface, so that the image fixing property is improved.

In the present invention, the term "polymer substance agglutinates the coloring material" means that the number of coarse particles in the ink is 0.5 μm or more, and that the 0.5 μm
The ratio with the number of coarse particles is in the range of 1: 1.1 to 1: 200. The mixture of the ink and the polymer substance referred to here is 1% by weight of the polymer substance with respect to the ink.
Indicates the added mixture. Although not particularly limited, the number of coarse particles having a particle size of 0.5 μm or more in the dispersed particles in the ink is preferably less than 1 × 10 ⁹ per liter. The number of coarse particles of 0.5 μm or more in the dispersed particles of
× 10 ⁹ or more is preferable.

Further, of the dispersed particles present in 1 liter of the mixture of the ink and the treating agent according to the present invention,
the number of particles of 1 μm or more is 1 × 10 ¹¹ or more, and
The number of particles having a size of 5 μm or more is preferably 1 × 10 ⁹ or more. The number of particles of 0.5 μm or more present in 1 liter of the mixed liquid is less than 1 × 10 ¹¹ , or the number of particles of 5 μm or more present in 1 liter of the recording material is 1 ×
If it is less than 10 ^9, the optical density is present may decrease. 0.5 μm present in 1 liter of the mixture
The number of the particles is preferably 2.5 × 10 ¹¹ or more, more preferably 5 × 10 ¹¹ or more.
The number of particles of 5 μm or more present in 1 liter of the mixture is
The number is preferably 5 × 10 ⁹ or more, more preferably 1 × 10 ¹⁰ or more.

In the present invention, the measurement of the number of particles 0.5 μm or more and the number of particles 5 μm or more
iser ^TM 770 Optical Particle
Sizer (Particle Sizing Sys)
2 μl of the measurement sample
The measurement was carried out by measuring the number of particles therein. As a parameter to be input at the time of measurement, the density of the coloring material was input as the density of the dispersed particles. The number of particles in the mixed liquid of the ink and the processing agent was measured so that the ink amount and the processing agent amount were mixed at a weight ratio of 1: 1 and the number of particles in the mixed liquid was measured according to the above method.

In the case of an ink in which the coloring material is a pigment, the number average particle diameter of the dispersed particles is 15 to 100 nm, and
It has been found that when the volume average particle diameter is 30 to 200 nm, the image quality, image fixability, and long-term storage stability are excellent. When the number average particle diameter in the pigment ink is smaller than 15 nm or when the volume average particle diameter is smaller than 30 nm, the optical density may be low. On the other hand, when the number average particle size is larger than 100 nm or when the volume average particle size is 200
When it is larger than nm, long-term storage stability may be deteriorated. Further, the number average particle diameter of the dispersed particles in the ink in which the coloring material is a pigment is preferably from 15 to 80 nm, more preferably from 20 to 70 nm.
On the other hand, the volume average particle diameter is preferably from 30 to 170 nm, more preferably from 30 to 150 nm.

In the present invention, a Microtrac UPA particle size analyzer 9340 (manufactured by Leeds & Northrup) was used as an apparatus for measuring the number average particle diameter and the volume average particle diameter. The measurement was performed by placing 4 ml of the ink in a measurement cell and following a predetermined measurement method. In addition, as a parameter to be input at the time of measurement, the viscosity of the ink is used for the viscosity,
The density of the pigment was input as the density of the dispersed particles. This device measures the particle size using the Brownian motion of a dispersoid, and irradiates a solution with laser light and detects the scattered light to measure the particle size.

Although not particularly limited, the ratio of the amount of the ink to the amount of the processing agent on the recording medium is 1: 5 to 5: 1.
Preferably it is 150: 1. More preferably 1:
It is in the range of 1-1: 10. Ink amount is 1 of processing liquid amount
If it is less than / 5 times, the printing characteristics may be poor. On the other hand, when the amount of ink is more than 150 times the amount of the processing liquid, the image fixability may be poor.

[0053]

The present invention will be described in more detail with reference to the following examples. [Pigment dispersion method 1] A water-soluble resin was added to 30 parts by weight of a pigment.
A total of 300 parts by weight was added by adding parts by weight and ion-exchanged water, and dispersed by using an ultrasonic homogenizer. This solution is centrifuged (8000 rpm ×
30 minutes) to remove 100 parts by weight of a residue portion. Next, this liquid was passed through a 1 μm filter to obtain a dispersion.

[Pigment Dispersion Method 2] With respect to a dispersion liquid of a pigment which can be self-dispersed in water, the dispersion liquid is subjected to a centrifugal separation treatment (8000 rpm × 30 minutes) by a centrifugal separator, and a residue portion (20% to the total amount) ) Was removed to obtain a dispersion.

[Pigment Dispersion Method 3] The pigment subjected to the plasma treatment was added to ion-exchanged water such that the pigment concentration became 20 wt%, and dispersed using a high-pressure homogenizer. This dispersion is centrifuged (80
00 rpm × 30 minutes), and the residue portion (20
%) Was removed to obtain a dispersion.

[Ink Preparation Method] To a proper amount of a coloring material dispersion or a coloring material solution, an appropriate amount of a water-soluble organic solvent, ion-exchanged water or the like was added to adjust the total amount to 100 parts by weight and the pigment concentration to a predetermined concentration. . This was mixed, stirred, and passed through a 1 μm filter to obtain a target ink.

[Processing agent preparation method] An appropriate amount of a polymer substance, ion-exchanged water, etc. was added to adjust to a predetermined concentration. This was mixed, stirred, and passed through a 5 μm filter to obtain the desired ink.

[Ink A] An ink having the following composition was obtained according to the above-mentioned pigment dispersion method 1 and ink preparation method. Carbon black (Black Pearls L: manufactured by Cabot Corporation) 5 parts by weight Styrene-methacrylic acid-sodium methacrylate copolymer 0.5 part by weight (St: MAA = 33: 67 / weight molecular weight: about 6200) Diglycerin ethylene oxide addition 10 parts by weight Diethylene glycol 5 parts by weight Isopropyl alcohol 3 parts by weight Urea 5 parts by weight Ion-exchanged water Remaining 100 parts by weight The viscosity of this ink is 3.2 mPa · s, the number average particle diameter is 35 nm, and the volume average particle diameter is 69 nm. Met.

[Ink B] An ink having the following composition was obtained according to the above-described pigment dispersion method 2 and ink preparation method. Surface-treated pigment (Cab-o-jet-300: manufactured by Cabot) 4 parts by weight Propylene glycol 10 parts by weight Glycerin 5 parts by weight Isopropyl alcohol 2 parts by weight Urea 5 parts by weight Surfactant (Surfinol 465: manufactured by Nissin Chemical Co., Ltd.) 1 part by weight ion-exchanged water balance 100 parts by weight in total The viscosity of this ink was 2.7 mPa · s, the number average particle diameter was 36 nm, and the volume average particle diameter was 82 nm.

[Ink C] An ink having the following composition was obtained according to the above-mentioned pigment dispersion method 3 and ink preparation method. Surface treated pigment (MA-100: manufactured by Mitsubishi Chemical Corporation) 4 parts by weight 2-ethylhexyl methacrylate-methacrylic acid-sodium methacrylate copolymer 1 part by weight (2EHMA / MAA = 50: 50 / weight average molecular weight about 5000) Thiodiethanol 10 parts by weight Diglycerin ethylene oxide adduct 5 parts by weight Surfactant (Nonion E-230: manufactured by NOF Corporation) 0.03 parts by weight isopropyl alcohol 3 parts by weight ion-exchanged water balance 100 parts by weight total The viscosity of this ink is as follows: 2.8 mPa · s, the number average particle diameter was 47 nm, and the volume average particle diameter was 98 nm.

[Ink D] An ink having the following composition was obtained according to the above-mentioned pigment dispersion method 1 and ink preparation method. CI Pigment Blue 15: 3 4 parts by weight Styrene-acrylic acid-sodium acrylate copolymer 1.2 parts by weight (St: AA = 33: 67 / weight molecular weight about 6100) Diglycerin ethylene oxide adduct 5 parts by weight Part Surfactant (Nonion E-215: manufactured by NOF Corporation) 0.03 parts by weight Ion-exchanged water balance 100 parts by weight in total The viscosity of this ink is 2.4 mPa · s, the number average particle diameter is 59 nm, and volume average particles The diameter was 135 nm.

[Ink E] An ink having the following composition was obtained according to the above-described pigment dispersion method 1 and ink preparation method. CI Pigment Red 122 4 parts by weight Styrene-acrylic acid-sodium acrylate copolymer 1.2 parts by weight (St: AA = 33: 67 / weight molecular weight about 6100) Glycerin 10 parts by weight Diethylene glycol monobutyl ether 3 parts by weight Surfactant (Pluronic PE6400: manufactured by BASF) 0.03 parts by weight Deionized water balance The remaining 100 parts by weight This ink has a viscosity of 2.9 mPa · s, a number average particle diameter of 62 nm, and a volume average particle diameter of 138 nm. Was.

[Ink F] An ink having the following composition was obtained according to the above-described ink preparation method. C. I. Acid Blue-9 3 parts by weight Styrene-acrylic acid-sodium acrylate copolymer 2 parts by weight (St: AA = 33: 67 / weight molecular weight about 6100) Glycerin 5 parts by weight Diglycerin ethylene oxide adduct 5 parts by weight Urea 3 Parts by weight ion-exchanged water balance 100 parts by weight in total The viscosity of this ink was 2.1 mPa · s.

[Ink G] An ink having the following composition was obtained according to the above-mentioned pigment dispersion method 3 and ink preparation method. Surface-treated pigment (Special Black 4A / made by Degussa) 4 parts by weight Diglycerin ethylene oxide adduct 5 parts by weight Surfactant (Surfinol 465: made by Nissin Chemical Co.) 1.5 parts by weight Isopropyl alcohol 3 parts by weight Ion exchange Water balance 100 parts by weight in total The viscosity of this ink was 1.4 mPa · s, the number average particle diameter was 15 nm, and the volume average particle diameter was 31 nm.

[Ink H] An ink having the following composition was obtained according to the above-described ink preparation method. CI Acid Blue-9 3 parts by weight Thiodiethanol 10 parts by weight Diglycerin ethylene oxide adduct 5 parts by weight Urea 6 parts by weight Surfactant (Surfinol 465: manufactured by Nissin Chemical Co.) 1 part by weight Ion-exchanged water balance 100 parts by weight in total The viscosity of this ink was 1.8 mPa · s.

[Treatment agent A] A treatment agent having the following composition was obtained in accordance with the above-mentioned treatment agent preparation method. Urethane resin 10 parts by weight (Pateracol IJ2: manufactured by Dainippon Ink and Chemicals, Inc.) 90 parts by weight ion-exchanged water

[Treatment agent B] A treatment agent having the following composition was obtained according to the above-mentioned treatment agent preparation method. Ether compound (Merpol F-220: manufactured by Sanyo Chemical Co., Ltd.) 10 parts by weight Calcium nitrate 10 parts by weight Deionized water 80 parts by weight

[Treatment agent C] A treatment agent having the following composition was obtained in accordance with the above-mentioned treatment agent preparation method. Polyvinyl alcohol 10 parts by weight Ion exchange water 90 parts by weight

[Treatment Agent D] A treatment agent having the following composition was obtained in accordance with the above-mentioned treatment agent preparation method. Polyvinyl alcohol 10 parts by weight Calcium nitrate 0.5 parts by weight Deionized water 89.5 parts by weight

Example 1 FX-L paper (plain paper, manufactured by Fuji Xerox Co., Ltd.) was bar-coated with a treating agent A at 5 g / m ² and air-dried. Printing was performed by a recording device.

(Example 2) The treatment agent B was applied to 4024 paper (plain paper, manufactured by Fuji Xerox Co., Ltd.) with a roller at a concentration of 5 g / m ^2, and the ink B was printed by a thermal ink jet recording apparatus.

(Examples 3 to 6 and Comparative Examples 1 and 2)
FX-L paper (plain paper, manufactured by Fuji Xerox Co., Ltd.) was coated with a treatment agent shown in Table 1 by a roller, and the ink shown in Table 1 was printed by a thermal inkjet recording apparatus.

In Examples 1 to 6, Comparative Examples 1 and 2, and the following test examples, a thermal inkjet recording apparatus used a prototype evaluation apparatus, and ink was printed by a thermal ink jet system of 400 dpi and 160 nozzles. The agent was applied to the recording medium by roller application. In addition, printing and evaluation in the following test examples were conducted under a general environment (temperature: 23 ± 0.5).
° C, humidity 55 ± 5% R. H).

(Test Example) A 100% coverage pattern and a line pattern were printed and left for 24 hours in a general environment. Fixing strength and optical density were evaluated using the 100% coverage pattern, and image bleeding was evaluated using the line pattern.

(Fixing strength) The fixing strength was evaluated on the recorded matter.
4.9 × 10 another blank FX-L paper⁴N / m ²No load
To the ink transferred to the blank FX-L paper.
About the sensory evaluation against a predetermined limit sample.
Evaluation was made based on the value.

(Optical Density) The optical density was measured using X-Rite 404 (manufactured by X-Rite Co.), and the optical density was 1.4 or more, and 1.2 or more.
Those with less than 4 were evaluated as Δ, and those with less than 1.2 were evaluated as x.

(Image bleeding) The image bleeding was evaluated by comparing the degree of line pattern bleeding with a predetermined limit sample and performing a sensory evaluation.

(Strikethrough) As for strikethrough, the optical density of the printed portion was measured from the back side of the paper using X-Rite 404 (manufactured by X-Rite). .25 or more were evaluated as x.
Table 1 shows the results.

[0079]

[Table 1]

As is clear from the results shown in Table 1,
In Examples 1 to 6, excellent results were obtained in all evaluation items as compared with Comparative Examples 1 and 2.

[0081]

As described above, the ink jet recording system of the present invention has excellent printing characteristics such as image bleeding, good image fixability, and good image irrespective of the type of recording medium.
The optical density is high, and strike-through can be prevented.

Continued on the front page (72) Inventor Toshiki Yui 1600 Takematsu, Minamiashigara-shi, Kanagawa Prefecture Inside Fuji Xerox Co., Ltd. (72) Inventor Takeshi Hashimoto 1600 Takematsu, Minamiashigara-shi, Kanagawa Prefecture Fuji Xerox Co., Ltd. F-term (reference) 2C056 EA05 EA13 HA42 2H086 BA02 BA34 BA53 BA55 4D075 CA35 DA04 DB18 DC27 EA05 EB22 EB33 EB38 4J038 CE051 CG001 DB001 DG001 DG111 DG121 DG261 HA246 HA336 HA376 HA406 JA43 JC13 PB11 PC10 4J039 BE03 BC04 BE03 BC14 BC03 EA15 EA16 EA17 EA19 EA42 EA43 EA47 GA24

Claims (2)

[Claims] 1. An ink jet recording method for attaching an ink containing a coloring material, a water-soluble organic solvent and water to a recording medium containing a polymer substance, wherein the polymer substance causes the coloring material to aggregate. Characteristic ink jet recording method. 2. An ink jet recording method comprising: attaching a treatment agent containing a polymer substance to a recording medium; and attaching an ink containing a coloring material, a water-soluble organic solvent and water to the recording medium. The inkjet recording method, wherein the polymer substance causes the color material to aggregate.