JPS5845272A - Ink composition for ink jet recording and ink jet recording method - Google Patents

Abstract

PURPOSE:The titled ink composition, consisting of polymeric latex particles consisting of a polyurethane polymer containing a dye and an aqueous medium for dispersing the particles, having a high concentration, capable of giving printed dots of improved roundness, and having improved storage stability. CONSTITUTION:A composition obtained by mixing polymeric latex particles consisting of a polyurethane polymer, containing a dye, preferably a hydrophobic dye, and having a particle diameter of preferably 0.02-0.5mu, and an aqueous medium necessary for dispersing the particles. The polyurethane latex preferably consists of a polyurethane derived from a polyol component which is a prepolymer (mixture) having two or more terminal hydroxyl groups and a molecular weight of 300-20,000 and repeating units of a lower alkyl ether, etc. and an isocyanate component of the formula (R is alkyl, arylene, alkylene bisarylene, etc.).

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an ink composition for inkjet recording and an inkjet recording method.

More specifically, the present invention relates to an inkjet recording ink composition comprising dye-containing polymer latex particles and an inkjet recording method.

The inkjet recording method is basically distributing information without bringing the recording head into contact with the recording carrier by starving the ink liquid and jetting ink droplets onto the recording carrier.
It has been adopted in printers and other devices because it produces no noise during recording, can perform high-speed recording, and can record on plain paper, and has become rapidly popular in recent years.

The conventionally known one-screw recording force type is as follows:
Pressure vibration m<includes charge amount control method, electric field control method, binary control force method, scattering angle control force method, etc. ), electrostatic acceleration type,
There are on-demand types, pressure pulse types, etc. That is, the inkjet method ejects ink by rapid reduction of the internal volume of the container, extrusion or suction with a constant pressure, or the electrostatic method in which ink is ejected from the nozzle by applying a signal voltage between the nozzle and the counter electrode. An ink jet method in which ink is ejected at an accelerated rate, and an ink mist method in which a smudge is generated by ultrasonic vibration are known.

The characteristics required for an ink composition used in this type of inkjet recording method or one-ink printing method are: l) having sufficient number of members necessary for recording, and -) preventing evaporation and drying (clogging) in the ejection nozzle. 11) When ink droplets adhere and form on paper, they dry immediately; ? r) The recorded ink does not bleed due to water↑sweat (the printed area disappears), and V) the physical properties do not change or deposits do not occur due to storage.

Conventionally, as ink compositions for inkjet recording, for example, ink compositions made by dissolving water-soluble acidic dyes or basic dyes in water and adding additives such as wetting agents and preservatives have been known. There is. However, since the dye in these ink compositions is water-soluble, the recorded ink may bleed due to water or sweat, or the printed area may disappear. Furthermore, these ink compositions have the disadvantage that when color recording is performed, the colors become dull due to mixing with each other.

On the other hand, ink compositions made of polymer latex containing dyes are known. For example, I# 146109/1983 discloses an ink composition consisting of vinyl polymer fine particles containing a hydrophobic dye and an aqueous medium in which a water-soluble dye is dissolved. Furthermore, Japanese Patent Application Laid-Open No. 55-139471 discloses an ink composition in which water-insoluble vinyl polymer latex particles are impregnated with a disperse dye.

Compared to inks made only of water-soluble dyes, these ink compositions do not bleed due to water or sweat because the dyes are retained in the polymer latex, and they provide gloss. It has the advantage of improving printed products.

However, the tonirupolymer latex had a small amount of dye impregnated and did not have sufficient impregnation storage stability. Moreover, as in the two examples above,
When a dye is present in the medium to increase the print quality, it is true that a sufficient level of dots can be obtained, but it has the disadvantage that bleeding occurs and the circularity of the printed dots is impaired. was.

The purpose of the present invention is to eliminate the above-mentioned drawbacks of conventional ink compositions using latex.
An object of the present invention is to provide an inkjet recording ink composition and an inkjet recording method, which have Lt- and provide printed dots with excellent roundness and have good storage stability.

The above object of the present invention is to provide an inkjet recording ink composition comprising polymer latex particles containing a dye and an aqueous medium necessary for dispersing the particles, wherein the polymer latex particles are made of a polyurethane polymer. This is achieved by a one-ink composition for inkjet recording.

Further, a recording medium for achieving the above object of the present invention is an inkjet recording ink composition comprising a polymer latex encapsulant completely containing a dye and a necessary aqueous medium in which the particles are dispersed. an ink composition characterized in that the ink composition is comprised of a polyurethane polymer, and a pressure chamber communicating with a nozzle is filled with the ink composition, the pressure chamber having at least a portion of its wall. is configured to be able to be deformed by an electromechanical transducer, and when an electrical drive pulse is applied, the actuation of the electromechanical transducer causes the at-internal force of the pressure chamber to be displaced, thereby increasing the internal volume of the pressure chamber. A part of the amount of the ink composition in the pressure chamber is jetted from the nozzle in the direction of the recording medium, and - one ink droplet is ejected from the nozzle in the direction of the recording medium. This is an inkjet recording method in which the volume of the pressure chamber is restored to the initial equilibrium state 11 of the ink after the droplet is ejected.

According to the present invention, an inkjet recording ink composition capable of jet recording which is actually stable only at a height of 111&lt;0&gt; can be obtained.

In general, polyurethane latex has a particularly high impregnation rate with hydrophobic dyes compared to vinyl poly-1-latex. That is, it is possible to stably impregnate a large amount of hydrophobic dye per 2 oxen weight over a long period of time. Furthermore, in a latex dispersion type 1 ink composition, increasing the latex powder concentration drastically reduces the dispersion stability. Therefore, with vinyl polymer latex having a low dye impregnation rate, it is difficult to create a stable ink composition at a high concentration. is extremely difficult.

Additionally, polyurethane latex can be impregnated with a wide variety of hydrophobic dyes compared to vinyl polymer latex, so ink compositions for color inkjet KI!
Suitable for #.

In the case of vinyl polymer latex, 1 g of dye @
However, when changing the polymer, the composition often has to be changed. In the case of polyurethane latex C, a latex of substantially the same composition is sufficient and has a wide tolerance to dyes.

Furthermore, polyurethane latex has excellent impregnation storage stability with hydrophobic dyes. In the case of 1-ink jet recording, the diameter of the 1-ink projection nozzle is 50 μm to 100 nmφ.
1. The greatest attention must be paid to precipitates and foreign matter in the ink composition. However, in the case of polymer latex, hydrophobicity precipitates in a short period of time due to cost increase over time. If polyurethane latex is used, dyes can remain sufficiently stable even during long-term storage. Therefore, polyurethane latex is suitable as the polymer latex for the 1-ink composition for 1-ink printing, and can provide the desired properties. It can be equipped.

The polyurethane latex will be explained in detail below.

Preferred polyurethane polymers include a polyol component and 1
The polyol component, derived from the socyanate component, consists of: (a) at least 42 hydroxy end groups and 30 hydroxy end groups;
0-20. a prepolymer or a mixture of prepolymers having a molecular weight of 100% and whose repeating units are lower alkyl ethers or lower alkyl esters, 10 to 100 moles relative to the polyol present, and (b) a positive or negative charge. A low molecular weight diol with or without a functional group giving 90 to 10 moles based on the polyol present.

The incyanate component has the formula: %Formula% (R in i represents an alkylene group, a cycloalkylene group, an arylene group, an alkylenebisarylene group, or a shin group in arylenebisal)-! Fru.

Particularly preferred φ polyurethane latexes are derived from caprolactone-containing prepolymers'. Useful polyurethane latexes include, for example, U.S. Pat. No. 2,968,575.
No. 3,213,049, No. 3,294,72
No. 4, No. 3,565,844, No. 3.388,0
No. 87, No. 3,479,310 and No. 3. F.S.
No. 73,484. Generally, polyurethane latices are produced by chain extending a prepolymer which is the reaction product of a diisocyanate and an organic compound having 2@ active hydrogen atoms. 2@
Useful organic compounds containing active hydrogen atoms are polyalkylene ether glycols, alkyd resins, polyesters, and polyester amides. Polyurethane latexes are generally made by whole emulsifying a prepolymer and then chain extension, eg, extending a 7-repolymer chain in the presence of water.

Useful polyurethane latexes are neutral or stabilized with anions or ions.

Anionic or field ion stabilized polyurethane latexes are formed by attaching charged groups to polyurethane. Groups useful in imparting a negative charge to the latex include carboxylates, sulfonates, and the like. Useful repeat units are derived from polyol monomers having these active functional groups, such as 2,2-bis(hydroxymethyl)propionic acid, N,N-bis(2-hydroxyethyl)glycine, and the like. Groups useful in imparting positive charge to the latex include quaternary amines, sulfonium salts, phosphinates, and the like. Useful repeating units include polyol monomers having tertiary amine groups or thio functionality, such as N-methyljetanolamine, 2,2
- thioethanol etc. are induced. An example of a useful book on anion-stabilized polyurethane latex and -ion stabilized polyurethane latex is U.S. Pat. No. 3,479,310 KF&! has been done. Particularly useful latexes are those stabilized with cations, such as rice ffi! 3. Fa 73.41'
This latex is described in the specification of No. 14.

A preferred polyurethane latex has the formula: [wherein R is an alkylene group having about 2 to 40 carbon atoms, an alkylene group containing a heteroatom such as oxygen, an alicyclic alkylene group, such as a cyclohexylene group, an alkylenebiscyclohexylene group] Silene and 1-phoron-1,4-di-1, unsubstituted and substituted arylene groups, fit, ttf phenylene groups, naphthylene groups and U)! j v y group, alkylenebisarylene group, arylenebisalkylene group, these groups preferably have 6 to 15 carbon atoms, and Rtit
R2, R5 and R5 are each independently an alkylene group having 2 to 10 atoms, a cyclohexine bis(oxyalkylene) group, such as tfl, a 4-cyclohexylene bis(oxyethylene) group, an arylene bisalkylene group, fjJ, t is selected from the group 25) consisting of a phenylene bismethylene group and the residue of a poly(alkylene oxide) of 2 to 500 repeating units having about 2 to 5.11 carbon atoms in the alkylene moiety, and R'' is Charcoal** Approximately 2 to 1 pieces
0 alkylene group, nG has about 2 to 1 carbon atoms
0 represents an alkylene group or an arylene group, each 2 independently represents 10- or -Nl(-, p and n
each independently represents an integer from 2 to 500, m represents O or 1, y represents 0 to 90 molar width of the diol component, and xFiy corresponds to 100 to 10 mol, and 2 is 1.1 ~2.0].

The minimum amount of incyanate is pre, N r - (D
Just enough of the diisocyanate, ie, zwl, to create a terminal incyanate group at the W'4 end, ie, a little more than 1 mole of diisocyanate per mole of diol. Advantageously, this ratio is close to 2 moles of diisocyanate to 1 mole of diol.

A particularly advantageous polyurethane latex is derived from glycol-terminated polycaprolactone.

These polyurethanes can be expressed by the above formula where m is 1 and 2 is 10-.

Various polyols and diisocyanates can be used. Useful polyols include:

(1) Diols, such as alkylene diols having from 2 to 1011 carbon atoms, arylene diols, such as hydroquinone and polyether diols of the formula: %formula%, in which R represents an alkylene group, such as poly(propylene)glyco -7M, e.g. Pluracol P-2010, Plur
acolM P-1010 (commercially available from BASF) and N
1ax PPG 2023 TM (commercially available from Yuon Φ Carbide).

(2) Triols, such as glycerol, 2-ethyl-
2-hydroxy-methyl-1,3-propanediol,
1,1.1-)limethylolpropane and 1.2.6
-hexandriol, and tetraols such as pentaerythritol, higher polyols such as sorbitol, and poly(oxyalkylene) # conductors of the polyhydric alcohols.

Other preferable polyols include a polyol having a hydroxyl group at the end 1i111, a molecular weight of about 5,000, and a low acid value and water content.
Examples include @-shaped polyesters, block copolymers of ethylene oxide and propylene oxide and diamines such as ethylene diamine, and caprolactone polymers having hydroxyl groups at the ends.

Representative diinsyanates useful in the present invention include 2,4- and 2,6-toluene diisocyanate;
Diphenylmethane-4,4'-diisocyanate, polymethylene diphenylene isocyanate, Pitoluene Di 1
socyanate, dianisidine diisocyanate, 1.5
-, Na7thalene diisocyanate), i, 6-Methane diisocyanate, bis(1-socyanatocyclohexyl)methane diisocyanate, Inholofuji-1 isocyanate, 224-trime, tyhexane diisocyanate and Kijidi-1-isocyanate.

The prepolymer is generally prepared by mixing the polyol and the diisocyanate tiIIIA under agitation at a temperature of about 25 DEG to 110 DEG C., which is useful. reaction【
It is advantageous to carry out in the presence of a solvent and optionally a catalyst. Useful solvents are ketones and esters, aliphatic hydrocarbon solvents such as heptane, octane, etc. and cycloaliphatic hydrocarbons such as methylcyclohexane. Useful catalysts are tertiary amines, acids and organometallic compounds such as triethylamine, stannous chloride and di-n-butyltin dilaurate. If the polyol and incyanate are liquids and the prepolymer is also a liquid, organic solvents are not essential.

After the prepolymer is produced, a latex is created by emulsifying the prepolymer and extending the chains in the presence of water. Emulsification of the prepolymer can be carried out in the presence of surfactants. If the prepolymer contains charged groups, there is no need to add additional surfactants. Chain extension of prepolymer is chain extension I@tm to emulsified prepolymer.
This is done by adding

A compound having at least two functional groups with useful chain-extending and active hydrogen atoms. Representative examples include water, hydrazine, primary and secondary cyanogens, amino alcohols, amino acids, oxyacids, diols or mixtures thereof.

Preferred chain extenders are water and primary and secondary diamines. Preferred diamines are 1,4-cyclohexenebis(methylamine), ethylenediamine, diethylenetriamine and the like. The amount of chain extender generally exceeds one socyanate equivalent of the prepolymer.

The particle diameter of the polyurethane latex preferably used in the present invention is 0.01 p to 1. Oj and 11i
KO,02j-%-0,51 is preferred.

The dye used in the present invention may be any dye as long as it can be impregnated into polyurethane latex, but hydrophobic dyes are particularly preferred. Hydrophobic dyes that can be used include monoazo, anthra-non, metal complex monoazo, diazo, heptadatecyanine, triallylmethane, other dyes, sublimable dyes, and monoazo dyes that are soluble in organic solvents. Examples include organic pigments.

Examples of the hydrophobic dyes used in the present invention are listed below, categorized by color.

Yellow: C,1,5olvent Yellow 19(C,1
, 13900A).

C,1,5olvent Yellow 21(C,1
,IF+690).

C,1,5olv@nt Yellow 61, C
,1,SolventYellow RO,Aizan
5pilen Yellow GRH8special
(manufactured by Hodogaya Chemical Industry Co., Ltd.).

Diarsin Yellow F (manufactured by Mitsubishi Chemical Industries, Ltd.), Diarsin Yellow
A (manufactured by Mitsubishi Chemical Industries, Ltd.), Yellowf
Luer G (manufactured by Sumitomo Chemical Co., Ltd.).

Orange: C,1,5olvent Orange 1 (C,1
, 11920).

C, 1,5olvent Orange 37, C
,1,SolvsntOrange 40,D
Diarealn Orange K (manufactured by Mitsubishi Chemical Industries, Ltd.), Diarealn Orange
G (manufactured by Mitsubishi Chemical Industries, Ltd.), Sumipla
stOrange 3G (manufactured by Sumitomo Chemical Co., Ltd.)
.

Red: C,1,8o1v@nt Red 8 (C,1,12
715LC,1,8o1vent Red 81,
C,1,5olvent Red82, C
,1,8o1vent R@d F14 ,C,
1,5olvent Red Zoo, Ori
@nt Oil 5carletφ308 (manufactured by Orient Chemical Industry Co., Ltd.), 5uldenR@d3B
(manufactured by Nakaga Kasei Co., Ltd.), DiaresinR@
d8 (Mitsubishi Chemical Industries, Ltd. @), Sumi
plugtRed Al1 (manufactured by Sumitomo Chemical Industries, Ltd.), Diareain Red K (manufactured by Mitsubishi Chemical Industries, Ltd.), 8umiplast Red 3
B < If Sumitomo Chemical Co., Ltd.

Diarasin Red EL (manufactured by Mitsubishi Chemical Corporation).

Diaresin Red H (Mitsubishi Chemical Industries, Ltd. 1.

Diaresin R@d LM (manufactured by Mitsubishi Chemical Industries, Ltd.).

Diareain R@d G (Mitsubishi Chemical Industries, Ltd. 1ri.

Alzln 8pil@n Red GEM 8pac
1 ml (Hodogaya Chemical Industry Co., Ltd. #14).

Pink: Diarea Pink M (manufactured by Mitsubishi Chemical Industries, Ltd.), gumiplamt Pink B, F
F (manufactured by Sumitomo Chemical Co., Ltd.).

Purple: C, 1,5olvent Violet l'l (C
, 1,42535B).

C,1,5olvent Violet 21,
Diaresin Vi.

1etA (manufactured by Mitsubishi Chemical Industries, Ltd.), Diare
sinViolet D (manufactured by Mitsubishi Chemical Industries, Ltd.)
, Sumiplant Violet RR (Sumitomo Chemical Co., Ltd.).

Blue color: C,1,5olvent Blue 2 (C,1,4
2563B).

M, 1.5olvent Blue 11 (C, T
, 61525).

C,1,5olvent Blue 25 (C,1,
74350).

C, 1,5olvent Blue 36, C,
1,5olventBlue 55, Aizen
5pilen Blue GNH (manufactured by Hodogaya Chemical Industries, Ltd.), Diaresin BlueG (manufactured by Mitsubishi Chemical Industries, Ltd.), DiaresinBlue
eC (manufactured by Mitsubishi Chemical Industries, Ltd.), Diare
sin Blue J, A, H, K', N (Mitsubishi Chemical Industries, Ltd. % formula % (Nto Chemical Industries, Ltd. II).

Green: C, T, 5olven Green 3 (C, L
61565).

Brown: C,1,5olvent Brown 3 (C,1,
11360).

Dlarasin Brown A (manufactured by Mitsubishi Chemical Industries, Ltd.).

Black color: C,1,8o1vent Black 3 (C,1,
26150).

C,1,5olvent Black 5 (C,1,
50415).

C,1,5olvent Black 7 (C,1,
50415).

C,1,8o1vent Blaek 22,
C,1,Ac1dBlack 123 (C,1,12
195), SumisolBlack ARso
l (manufactured by Sumitomo Chemical Co., Ltd.).

Wall Fast Blackφ1802 (Orient Chemical Industry Co., Ltd. II).

The hydrophobic dyes mentioned above are typical examples, and hydrophobic dyes used in, for example, photographic materials for the silver-fermentation method and photographic materials for the diffusion transfer method can also be effectively used in the present invention.

Furthermore, the hydrophobic dye used in the present invention is divided into the vinyl I remer latex in the form of a dye precursor, and then,
The dye precursor may be made into a dye by physical or chemical means such as heat treatment, PR change, or addition of a color developer. An example of this dye precursor is a photographic coupler. Examples of agents include photogenic agents.

The dye-containing polyurethane latex used in the present invention can be produced by various methods. Specific methods include US Pat. No. 4,199°363;
British Patent Publication No. 2,003,486, JP-A-53-1
Examples include methods of impregnating a hydrophobic substance into a polymer latex, such as those disclosed in Japanese Patent Publication No. 37131 and Japanese Patent Publication No. 55-50240. According to these methods, polyurethane latex can be used instead of vinyl polymer latex. That is, first, a dye (hereinafter, a hydrophobic dye will be explained as a representative) 1 a suitable water-miscible organic solution #lK
A method is to prepare a solution of hydrophobic dye by dissolving it, then mix polyurethane latex with this solution, and finally remove the water-miscible material and impregnate the hydrophobic dye into the latex particles. Can be mentioned.

As for the 77 ships preferred by the military, the following methods can be cited.

First, a water-miscible solvent is mixed into the polyurethane latex. Next, the hydrophobic dye is added to this solution in solid or liquid form and stirring is continued. And the solid phase or liquid phase force of only hydrophobic dyes! Once the water is gone, the water-miscible organic solution is finally removed and the hydrophobic dye is impregnated into the latex particles.

Useful water-miscible solvents include solvents such as acetone, ethyl alcohol, methyl alcohol, 1-soprobyl alcohol, dimethyl formamide, methyl ethyl ketone, tetrahydro 7-lane N-methyl-2-pyrrolidone, dimethyl sulfoxide, and the like.

A preferred method of impregnating latex particles with hydrophobic dyes is described in detail. However, it is clear that other methods can also be used. For example, a hydrophobic pigment and a polyurethane latex can be combined with a hydrophobic dye, I! It is selected to be soluble in the monomer or prepolymer used to make the ls polyurethane latex. Chain extension of the prepolymer using a dissolved hydrophobic dye provides a hydrophobic dye-containing polyurethane latex that can be used in the present invention.

The polyurethane latex containing the hydrophobic dye used in the present invention must contain, for example, an ultraviolet absorber,
Dye stabilizers such as antioxidants and other additives may be included together with the hydrophobic dye.

The weight ratio of latex particles to hydrophobic dye in the polyurethane latex containing the hydrophobic dye of the present invention is 0.
5-20:1 is preferred, 0.5-5:1 is particularly preferred.

The 111 degrees of polyurethane latex particles containing a hydrophobic dye in all ink compositions should be 0.5 to 10 parts by weight, based on 100 parts by weight of the entire ink composition, in order to improve print quality. and is preferable in terms of stability.

The ink composition of the present invention includes an aqueous dispersion of polyurethane latex containing a hydrophobic dye obtained by the method described above, a wetting agent, an antifungal agent, a surfactant, a chelating agent, and the like necessary for one ink composition. It can be obtained by adding pH-adjusting additives or the like. However, these additives can be added to the polyurethane latex solution prior to impregnation with the hydrophobic dye. In particular, the method of adding a wetting agent to the latex before impregnation with hydrophobic dyes is advantageous for obtaining inks with high dye a degree.

The wetting agent lowers the vapor pressure of the entire ink, slows down the evaporation of water in the ink, and also prevents clogging of the nozzle orifice by dispersing the polyurethane latex particles containing the hydrophobic dye to some extent. Therefore, first of all, it is preferable to use a wetting agent that has good water solubility, water absorption, and high dispersion power for polyurethane latex particles. and acetate II conductors of aliphatic polyhydric alcohols are excellent. Specifically, polyhydric alcohols such as ethylene glycol, diethylene glycol, triethylene glycol, furohylene glycol, polyethylene glycol, glycerin, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, diethylene glycol monoethyl ether, diethylene glycol motsubutyl ether , diethylene glycol methyl ethyl ether, triethylene glycol monomethyl ether and other alkyl ether derivatives of polyhydric alcohols such as L ethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, glyceryl monoacetate and glyceryl diacetate There are acetate II conductors, and mixtures of the above-mentioned polyhydric alcohols, alkyl ether a conductors of polyhydric alcohols, and acetate Il! conductors of polyhydric alcohols are also used.
be able to.

Among these wetting agents, those with an HLB value of 9.5 or less have good permeability to plain paper and when used as a penetrating solvent,
A quick-drying ink that dries well on paper can be obtained. However, even in this case, it is preferable to use a wetting agent having an HLII value exceeding 9.5.

Particularly preferred as the penetrating solvent are sial ether haze conductors of polyhydric alcohols such as diethylene glycol dimethyl ether, diethylene glycol dimethyl ether, and tetraethylene glycol dimethyl ether.

In the present invention, 5 to 50 parts by weight of wetting agent, 5 to 70 parts by weight
It is preferable to add parts by weight of a penetrating solvent, and if the viscosity is adjusted arbitrarily within this range (R' is an alkylene group, and R1, R2, and R5 are alkyl groups), N-hydroxyalkyl-2- Pyrrolidones (R1, R
t, R5, and R are alkyl groups. ) denoted by N-
It is also possible to add alkyl-2-pyrrolidones, and it has been found that by adding 1 to 30 parts by weight to these components 1, the effect of preventing clogging in the nozzle orifice is improved. . Known anti-mold agents such as dioxin and sodium dehydroacetate can be used for long-term storage and as anti-mold agents to suppress the growth of bacteria and mold. Surfactants can be used to improve ink wetting and to improve dispersion stability of latex particles. Preferred surfactants depend on the particular latex and hydrophobic dye, optionally anionic, mono-ionic,
#1-on, non-1-on, or mixed negative 1-on-non-1-on. Preferred surfactants include polyethylene glycol ethers of long-chain diols, quaternary ammonium salts, tertiary amine salts or alkylolamine salts of long-chain alkyl and sulfuric esters, alkylsulfonic acids, alkylarylsulfonic acids and their salts. , alkali metal salts of high molecular weight organic acids, etc. Nonionic surfactants, such as polyoxyethylene and poly(propylene glycol) and polyethyleneoxyethanol, are particularly preferred.

The amount of these surfactants added is generally 1% by weight or less based on the total amount of the ink composition, but it is preferably in the range of 0.05% to 0.1% by weight.

Furthermore, various non-contact or organic buffers can be added to the ink for the purpose of preventing pH changes caused mainly by absorption of carbon dioxide gas in the air during storage in a container or residence in a nozzle. For example, F! is a desirable book. Examples include sodium carbonate and potassium carbonate, but the amount of these added is practically -0.1 to 5% of the total ink composition.
Weight is appropriate, preferably 0.1 to 2 weight.

Further, wood chelate can be added for the purpose of masking the gold tone and gold color in the ink composition. Representative examples include sodium gluconate, ethylenediaminetetraacetic acid (ff1DTA), disodium salt, trisodium salt, trisodium salt, sodium salt of diethylenetriaminopentaacetic acid, and the like.

The present invention will be described below with reference to Examples, but these Examples will further specifically explain the present invention.
The embodiments are not limited to these details.

The polyurethane latex used in this example was all manufactured by the method described in US Pat. No. 3, FI73,484.

Example 1 Polyurethane latex having the following composition (solid content a
ljij6 weight 1) To 100g, add 100g of ace) and 10g of ethyl acetate, and while stirring with a stirrer, add C, 1,
5olvent Blue 2 (C, 1, t@'42
563B) was gradually added. After uniformly dissolving the mixture, the solvent was removed using an evaporator to obtain a hydrophobic dye-containing aqueous dispersion having a dye concentration of over 6% by weight.

16.7 (mol '14. The same applies hereinafter.) To this aqueous dispersion was added 92 g of tetraethylene glycol dimethyl ether, 36 g of diethylene glycol, and [
The ink of the present invention, which was made uniform by adding 12 g of potassium carbonate by 10 weight, passed v1 without clogging in Toyo Paper Department 131 (specially made by Toyo Paper)! Ta.

The ink of the present invention has a viscosity of 7.3 centipoise (epa) and a surface tension of 42.5 d at room temperature (25°C).
yn/1, and there was no change over time even after one month of storage, and no precipitation was observed.

Example 2 Aceto 7150 gK C,1,1olvent Re
d J'S (C.

■, Ugly 12715) 6gt-Melt, and stir with Star2, polyurethane latex of the following composition (solid concentration f8
Weight 1) 100g was gradually dropped. After dropping all fi, the solvent was removed using an evaporator to obtain a hydrophobic dye-containing polyurethane latex having a weight of dye layer IjIL6.

Add 92 g of diethylene glycol monobutyl ether to this aqueous fraction 1 36 g of polyethylene glycol◆400
5 Sara Kl 0 weight 11G! i2a! [! Cali9412
The ink of the present invention made uniform by adding g is produced by Toyo V Paper Department 13
1 was able to filter without clogging. The ink of the present invention has a viscosity of 7.6 epx and a surface tension of 30.5 at room temperature (25°C).
dyn/cm, and there was no change over time during storage for one month, and no precipitates were observed.

Example 3 100 g of polyurethane latex (solid concentration f10 weight 1) having the following composition, 100 g of tetraethylene glycol dimethyl ether, 37.5 g of glycerin, and 250 g'i of tetrahydro7ran were added, and a blue hydrophobic dye (2- tert-butylsulfonyl-4-(2-methylsulfonyl-4-nitrophenylazo)-5-(3-annosulfonylbenzenesulfonami)')-1-? 7 Torr) 1 Gg was gradually added. Dissolve it uniformly and remove the tetrahydrogen 07 run using an evaporator, and finally add 12.5 mg of potassium carbonate with an amount of 101.
was added to dye 11 to obtain an ink of the present invention consisting of a polyurethane latex impregnated with a hydrophobic dye of 4 weight by weight, hydrophobic dye: polyurethane=1=1. The ink of the present invention filtered through Toyo P paper Na131 has a viscosity K of 8 at normal temperature (25°C).
-Ocps % surface tension was 38.3 dyn/cm, and the precipitate did not disappear even after storage for one month.

Comparative Example 1 Example 1 was repeated except that a polyurethane latex having the following composition was used instead of the polyurethane latex. The obtained ink showed a large amount of precipitate after one week.

Comparative Example 2 For comparison, the same operation as in Example 3 was carried out using a vinyl polymer latex having the following composition, but the hydrophobic dye was not completely impregnated but was partially precipitated. The ratio of the impregnated hydrophobic dye to the polymer latex was determined to be 0.67:1.

H5 Example 4 The ink compositions obtained in the above Examples and Comparative Examples were described in US Pat. No. 4,189,734, $1-31! One-ink jet recording was performed using a one-ink jet recording device made by Kyoto, adjusting the parameters KN shown in Table 1. These results are shown in Table 2, and it is clear that the 1st ink of the present invention is superior.

Table-1 531

Claims (1)

[Scope of Claims] +1) 17 consisting of a polymer latex a particle having a dye t' and an aqueous medium necessary to disperse the particles.
', an ink composition for inkjet recording, characterized in that the polymer latex particles are made of a polyurethane polymer. (2) The ink composition for inkjet recording according to claim 1, wherein the dye is an acid aqueous dye. - (3) The ink composition for inkjet recording according to claim 1 or 2, wherein the polyurethane latex is composed of polyurethane formed from a polyol component and an incyanate component. (4) The polyol component is a prepolymer or prepolymer mixture having at least two hydroxyl end groups and a molecular weight of 300 to 20,000, and the repeating unit is a lower alkyl ether group is a lower alkyl ester. The ink composition for inkjet recording according to claim 3, characterized in that: (5) The incyanate component is represented by the formula % (wherein R represents an alkylene group, a cycloalkylene group, an arylene group, an alkylenebisarylene group, or an arylenebisalkylene group). The ink composition for inkjet recording according to claim 93. (6) The polyurethane latex has the formula: [wherein R
represents an alkylene group, an alkylene group containing a heteroatom, an alicyclic alkylene group, an arylene group, an alkylenebisarylene group, or an arylenebisalkylene group;
is −(−z R'tez+g+, R' −)−, z −
and R2, R5 and R5 are each independently selected from the group consisting of an alkydone group and a substituted alkylene group, RF represents an alkylene group having 2 to 10 carbon atoms, and R6 represents an alkylene group having 2 to 10 carbon atoms. represents an alkylene group or an arylene group, each 2 independently represents 10- or -NH-, and p and n each independently represent 2 to 50
represents an integer of 0, m represents O or 1, y represents a geo-
A patent claim characterized in that the component is represented by the following formula (D O ~ 90 mol, X corresponds to y and is 100 to 10 mol, and 2 is 1.1 to 2.0.) range 1
1. The one-ink composition for inkjet recording according to item 1, 2, 3, 4, or 5. (7) A pressure chamber communicating with the nozzle is filled with an ink composition, the pressure chamber is configured to be able to deform at least a portion of the sled member by electromechanical conversion means, and an electrical drive pulse is applied. At this time, W in the pressure chamber is displaced inward by the operation of the electromechanical conversion means, the internal volume of the pressure chamber is electrically reduced, and a part of the amount of the ink composition in the skeleton pressure chamber is an inkjet that is ejected as ink droplets from a nozzle in the direction of the recording medium, and - after ejection of some ink droplets in response to a drive pulse, the volume of the pressure chamber is restored to the initial ink equilibrium state 11; 1. A one-ink jet recording method, characterized in that the ink composition comprises polyurethane latex grains containing a dye and an aqueous medium necessary to disperse the particles. (8) 1% mark indicates that the dye is a hydrophobic dye;
An inkjet recording method according to claim 7. (9) The inkjet recording method according to claim 7 or 8, wherein the polyurethane latex is made of polyurethane formed by forming grooves from a polyol component and a one-layer net component. The αQ polyol component is a prepolymer or a mixture of prepolymers having at least 2 hydroxy end groups and a molecular weight of 300 to 20,000, the anti-oxidation units being lower alkyl ethers or lower alkyl esters. An inkjet recording method according to claim 9. al) 1 socyaneto component is represented by the formula: %Formula% (wherein R represents an alkylene group, a cycloalkylene group, an arylene group, an alkylenebisarylene group or an arylenebisalkylene group) Inkjet method #1 according to claim 9. 03 The polyurethane latex has the formula: [wherein R represents an alkylene group, an alkylene group containing a hetero atom, an alicyclic alkylene group, an arylene group, an alkylenebisarylene group, or an arylenebisalkylene group; R2, R and R5 are each selected from the group consisting of an alkylene group and a substituted alkylene group, R represents an alkylene group having 2 to 10 carbon atoms, and R
represents an alkylene group or arylene group having 2 to 10 carbon atoms, and each 2 is independently 10- or -NH-
, p and n each independently represent an integer from 2 to 500, m represents O or 1, and y represents the diol component O.
O~90 molar h, corresponding to xFiy 100~1
0 mole I regret it! is 1.1 to 2.0. ], which is expressed as t%. Claims 7 and 8
1. The one-ink jet recording method according to paragraph 9, paragraph 10, or paragraph 11.