AU722045B2 - Liquid composition and ink set, and image-forming process and apparatus using the same - Google Patents

Description

S F Ref: 290659D1

AUSTRALIA

PATENTS ACT 1990 COMPLETE SPECIFICATION FOR A STANDARD PATENT

ORIGINAL

Name and Address of Applicant: Canon Kabushiki Kaisha 30-2, Shimomaruko 3-chome Ohta-ku Tokyo 146

JAPAN

Yutaka Kurabayashi, Kellchi and Katsuhiko Takahashi 0 0000 0@*O 0 000* 000 0 00 0 Actual Inventor(s): Mural, Katsuhiro Shirota Address for Service: Spruson Ferguson, Patent Attorneys Level 33 St Martins Tower, 31 Market Street Sydney, New South Wales, 2000, Australia Liquid Composition and Ink Set, and Image-Forming Process and Apparatus Using the Same Invention Title: 0 0* 0 0 The following statement is a full description of this invention, including the best method of performing it known to me/us:- 000.

0 @000 0

CO..

CO

@0 0

C

5845

I

i 1 LIQUID COMPOSITION AND INK SET, AND IMAGE-FORMING PROCESS AND APPARATUS USING THE SAME BACKGROUND OF THE INVENTION Field of the Invention The present invention relates to a technique capable of lessening bleeding which occurs upon the formation of color images with inks and providing images high in water fastness. In particular, it relates to an image-forming process and an apparatus making good use of an ink-jet system, and a liquid composition and an ink set, which are suitable for use in such process and apparatus.

Related Background Art An ink-jet recording method is a system in which recording is conducted by flying out droplets of an ink to apply them to a recording medium such as paper. In particular, according to the methods disclosed in Japanese Patent Publication Nos. 61-59911, 61-59912 and 61-59914, in which an electrothermal converter is used as an ejection-energy supply means to apply thermal energy to an ink so as to generate bubbles, thereby ejecting droplets of the ink, the formation of a high-density multi-orifice in a recording head can be realized with ease, and highresolution and high-quality images can be recorded at high speed.

However, the conventional inks used in ink-jet 2 1 recording generally comprise, as a principal component, water, and include additionally a water-soluble high boiling solvent such as glycol for the purpose of Preventing drying and clogging, and the like. When such an ink has been used to conduct recording on plain paper, there have been encountered disadvantages that fixing ability cannot be sufficiently achieved, and image irregularity occurs, which appears to be attributed to the uneven distribution of the filler and size on the surface of the recording paper. In particular, when color images are intended to form, plural inks of different colors are overlapped one after another before they are fixed to paper. Therefore, color bleeding and uneven color mixing have occurred at portions of boundaries between images of 15 different colors (this phenomenon will hereinafter be referred to as "bleeding" simply), resulting in a failure e to obtain satisfactory images.

o o As a means for enhancing fixing ability of inks, oooo *Japanese Patent Application Laid-Open No. 55-65269 discloses the addition of a compound capable of enhancing 'p"penetrability, such as a surfactant, into the inks.

Besides, Japanese Patent Application Laid-Open No. 66976 discloses the use of inks comprising, as a principal component, a volatile solvent. However, the former method has involved a disadvantage that although the penetrability of the inks into recording paper is penetrability of the inks into recording paper is 3 1 improved, and so the fixing ability is improved and bleeding can be prevented to some extent, the image density and the saturation of the resulting image are lowered because coloring materials penetrate deeply into the recording paper together with the inks. In addition, the inks have also involved a problem that they spread in lateral directions, resultingi in reduction of edge sharpness and resolution. On the other hand, the latter method is liable to cause clogging due to the evaporation of the solvent in a nozzle of a recording head in addition to the above-described disadvantages.' Such methods have hence not been preferred.

In order to improve the above-described problems, further, there have been disclosed methods of applying a 15 liquid, which can make the quality of images better, to a recording medium prior to the jetting of a recording ink.

o:i" For example, Japanese Patent Application Laid-Open 0009 No. 63-60783 discloses a method in which a liquid S containing a basic polymer is applied to a recording medium, and recording is then conducted with inks 0 containing an anionic dye. Japanese Patent Application 0000 0 Laid-Open No. 63-22681 discloses a recording method in which the first liquid containing a reactive chemical 00* species and the second liquid containing a compound 25 reacting with the reactive chemical species are mixed on a .009 recording medium. Japanese Patent Application Laid-Open @0 0 4 1 No. 63-299971 discloses a method in which a liquid containing an organic compound having two or more cationic groups per molecule is applied to a recording medium, and recording is then conducted with inks containing an anionic dye. Japanese Patent Application Laid-Open No.

64-9279 discloses a method in which an acidic liquid containing succinic acid or the like is applied to a recording medium, and recording is then conducted with inks containing an anionic dye.

Further, Japanese Patent Application Laid-Open Nos.

64-63185 and 64-69381 disclose a method of applying a liquid, which insolubilizes dyes, to a recording medium prior to recording.

However, all these methods intend to prevent bleeding of images or improve the water fastness of images owing to the deposition of the dyes themselves in the o..o inks. Therefore, these methods are still insufficient in the effect to prevent the above-described bleeding between e. inks of different colors, and moreover poor in coverability of the inks on pulp fibers in the recording paper because the dyes deposited tend to distribute unevenly on the recording paper, resulting in reduction of evenness of images.

present invention has been completed with a view toward satisfying the following five requirements for ink-jet recording on plain paper: being able to provide image excellent in quality of characters, while retaining good fixing ability; being able to achieve sufficient image density and provide solid images high in evenness; and in .particular, upon formation of color images on plain paper 1 o being able to prevent bleeding; being excellent in color reproductivity and being able to provide high-fine images; and being able to achieve perfect water fastness of recorded images.

The above object can be achieved by the present invention described below.

In the first aspect of the present invention, there is provided a liquid composition for use in an ink-jet image forming process with an ink containing an anionic dye or an anionic compound and a pigment, and for use in an ink-jet ejecting process, comprising a cationic substance and a nonionic polymeric substance, the liquid composition reacting with the ink to cause the anionic dye or anionic compound in the ink to aggregate when the liquid composition contacts with the ink, wherein the cationic substance has a weight average molecular weight of at most 1,000, and 25 the nonionic polymeric substance has a weight average molecular weight of at least 2,000.

C

[N :\libaa]00978:rmn 6 In the second aspect of the present invention, there is provided a liquid composition for use in an inkjet image forming process with an ink containing an anionic dye or an anionic compound and a pigment, and for use in an ink-jet ejecting process, comprising a cationic oligomer having a weight average molecular weight distribution in which a peak exists when being measured by GPC method, and a nonionic polymeric substance, wherein the cationic oligomer reacts with the anionic dye or anionic compound in the ink to cause the anionic dye or anionic compound to aggregate when the liquid composition contacts with the ink, and wherein the peak exists in the weight average molecular weight distribution of not higher than 1,000, and the nonionic polymeric substance has a weight average molecular weight of at least 2,000.

9*9* 9 9** S* 9 0 [N:\libaa]00978:rmn Brief Description of the Drawings Fig. 1 is a longitudinal cross-sectional view of a head of an ink-jet recording apparatus.

Fig. 2 is a transverse cross-sectional view of the head of the ink-jet recording apparatus.

Fig. 3 is a perspective view of the appearance of another head of the ink-jet recording apparatus.

Fig. 4 is a perspective view of an illustrative ink-jet recording apparatus.

Fig. 5 is a longitudinal cross-sectional view of an o* *6 e4

S

0 [N:\libaa]00978:rmn 8 1 ink cartridge.

Fig. 6 is a perspective view of a recording unit.

Fig. 7 is a perspective view illustrating a recording part used in examples of the present invention, in which a plurality of recording heads is arranged.

Fig. 8 is a perspective view of another recording head used in the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The operation of the present invention will hereinafter be described.

In the present invention, the liquid composition and an ink or a pigment ink are mixed on recording paper or at a position penetrated in the recording paper. As a result, as the first step of the reaction, the lowmolecular weight cationic substance or cationic oligomer contained in the liquid composition associates with a oo Swater-soluble dye having an anionic group used in the ink or an anionic compound used in the pigment ink owing to ionic interaction, so that they momentarily separate from the respective solution phases. As a result, breaking of dispersion occurs in the pigment ink, whereby aggregates of the pigment are formed.

*000 ~As the second step of the reaction, the aggregates 25 formed by the association of the dye and the low-molecular ooo• 06 0 9 1 weight cationic substance or cationic oligomer, or the aggregates of the pigment are adsorbed on the nonionic or cationic polymeric substances. Therefore, the aggregates of the dye formed by the association in the dye ink, or the aggregates of the pigment further increase in size, and become difficult to enter the interfiber spaces of the recording paper. As a result, only the liquid component separated from the solid component is caused to penetrate into the recording paper, whereby the compatibility of print quality and fixing ability can be achieved. At the same time, the aggregates formed from the low-molecular weight cationic substance or cationic oligomer, the anionic dye in the ink or the anionic compound and pigment in the pigment ink, and the nonionic or cationic polymeric substances increase in viscosity and hence do not move *:4S •with the movement of the liquid medium. In this case, the preferable molecular weights of the polymers are at least 2,000 for the nonionic polymers, and at least 1,500 for the cationic polymers. Accordingly, the coloring ability of the dye or pigment is improved, and inks of different colors are not mixed with each other even if adjoining dots are formed by these inks, for example, upon formation of a full-color image, and so bleeding does also not 9 occur. Since the aggregates are insoluble in water in 2lieof themselves, the image formed comes to have perfect water 6004 oee° 0o *4O 10 1 fastness. When the pigment is used as a coloring material, the pigment aggregates on the surface of the recording paper, and so the coverability of the resulting ink is increased, ,resulting in marked improvement of coloring ability.

The preferred embodiments of the present invention will then be described to explain the present invention in more detail.

First of all, the liquid composition according to the first aspect of the present invention will be described.

The essential components to be contained in the colorless or pale-colored liquid composition described in the first aspect of the present invention are as follows: a low-molecular weight cationic substance having a molecular weight of at most 1,000, and a nonionic polymeric substance having a molecular weight of at least 2,000.

On the other hand, the inks used in the present invention comprise: a water-soluble dye having at least an anionic 00 group, while other inks used in the present invention comprise: 0 0 a pigment and an anionic compound.

The action and effect of the above-described 11 1 substances are as described above. More specifically, the low-molecular weight cationic substance of the component having a molecular weight of at most 1,000 (preferably, 100 to 700) associates with the water-soluble dye of the component having at least an anionic group, which is contained in the ink, or the anionic compound of the component in the pigment ink owing to ionic interaction to form aggregates. The rate of this aggregate-forming reaction must be extremely fast.

Preferable specific examples of the low-molecular weight cationic substance of the component having a molecular weight of at most 1,000, preferably from 100 to 700, are mentioned below.

As the preferable examples thereof, may be mentioned compounds of the primary, secondary and tertiary amine salt types, specifically, the hydrochlorides, acetates and the like of laurylamine, coconut amine, stearylamine, rosin amine and the like, and besides compounds of the .0* quaternary ammonium salt type, specifically, lauryltrimethylammonium chloride, lauryldimethylbenzylammonium chloride, benzyltributylammonium chloride, benzalkonium chloride, cetyltrimethylammonium chloride and the like, pyridinium salt type compounds, specifically, cetylpyridinium chloride, cetylpyridinium bromide and the like, imidazoline type cationic compounds, specifically, 12 1 2-heptadecenylhydroxyethylimidazoline and the like, and ethylene oxide adducts of secondary alkylamines, specifically, dihydroxyethylstearylamine and the like.

In the first aspect of the present invention, amphoteric surfactants exhibiting cationic properties in a certain pH region may also be used.

More specifically, there are mentioned amino acid type amphoteric surfactants, compounds of the RNHCH 2

CH

2 COOH type, betaine type compounds, specifically, stearyldimethylbetaine and lauryldihydroxyethylbetaine, and the like. If these amphoteric surfactants are used, it goes without saying that the colorless or pale-colored liquid composition must be adjusted either so as to have a pH not higher than their isoelectric point or so as to reach the pH not higher than the isoelectric point when

SJ

4, mixed with the ink on a recording medium.

1.4 Although the examples of the low-molecular weight cationic compounds have been mentioned above, it goes without saying that cationic compounds usable in the first aspect of the present invention are not always limited to these compounds.

The action and effect of the nonionic polymeric substance of the component having a molecular weight of at least 2,000 in the first aspect of the present invention are as described above. More specifically, as

S

13 1 the second step of the reaction of the liquid composition with the ink, the aggregates of the above-described dye or the anionic compound in the pigment ink and the lowmolecular weight cationic substance formed by the association are adsorbed into its molecule to increase the size of the aggregates of the dye or the pigment formed by the association so as to become difficult to enter the interfiber spaces of the recording paper, whereby only the liquid component separated from the solid component is caused to penetrate into the recording paper to achieve the compatibility of print quality and fixing ability.

As specific examples of the component may be mentioned nonionic water-soluble polymers, i.e., polyacrylamide, polyvinyl pyrrolidone, water-soluble cellulosics such as carboxymethylcellulose, hydroxymethylcellulose and hydroxypropylcellulose, polyvinyl methyl ether, polyvinyl acetal, and polyvinyl alcohol. It goes without saying that the component is limited to these too** polymeric substances. The effect of these polymeric C. S substances in the practice of the present invention can be sufficiently achieved so far as they have a molecular weight of at least 2,000. However, polymeric substances having a molecular weight of not lower than 2,000 but not higher than 10,000 are more preferred.

The molecular weight of the polymeric substance in the present invention means a weight average molecular 14 1 weight determined in terms of polyethylene oxide by means of GPC (gel permeation chromatography) unless expressly .noted.

The amount of these components to be contained in the colorless or pale-colored liquid composition may preferably be within a range of from 0.05 to 20 by weight, more preferably from 0.5 to 5 by weight based on the total weight of the liquid composition. It is however necessary to determine an optimum range according to the combination of the individual substances to be used. The mixing ratio of the low-molecular weight cationic substance of the component to the polymeric substance of the component in the liquid composition is within a range of from 10:1 to 1:10, preferably from 5:1 to 1:5 by weight. If this ratio exceeds 10:1, the water fastness of the resulting print tends to be deteriorated. On the 0O e o. other hand, if the ratio is not lower than 1:10, the .•go prevention of bleeding becomes insufficient, and so the edge sharpness of images formed tends to be reduced.

Second, the liquid composition according to the second aspect of the present invention is a liquid

OS

composition comprising a cationic substance and o. S *characterized in that the composition comprises in see@ combination a cationic oligomer having a molecular weight distribution in which a peak exists in a molecular weight rh0i region of not higher than 1,000, and a nonionic polymeric o• S.

15 1 substance having a molecular weight of at least 2,000.

The liquid composition may preferably further contain a cationic surfactant.

The action and effect of the liquid composition according to the second aspect of the present invention are as described above. More specifically, the cationic oligomer contained in the liquid composition, which has a molecular weight distribution in which a peak exists in a molecular weight region of not higher than 1,000, first associates with the anionic compound contained in the ink owing to ionic interaction to form aggregates. The rate of this aggregate-forming reaction must be extremely fast.

The components of the liquid composition according to the second aspect of the present invention will 15 hereinafter be described. As specific examples of monomer units forming the cationic oligomer having a molecular weight distribution in which a peak exists in a molecular weight region of not higher than 1,000, said oligomer being an essential component to the liquid composition according to the second aspect of the present invention, may be mentioned vinylamine, allylamine, vinylpyridine, vinylimidazole, N,N-dimethylaminoacrylamide, ethyleneimine and 2-oxazoline. However, the monomer units are not limited to these compounds.

Examples of cationic oligomers formed from the monomer units mentioned above include polycations such as 16 1 polyvinylamine, polyallylamine, polyvinylpyridine and polyethyleneimine and the hydrochlorides, acetates and sulfates thereof, and besides the quaternary ammonium salts of polyoxyethylene derivatives, which have the structure

(C

2

H

4 0)mH [R N X-

(C

2

H

4 0)nH wherein R and R' denote individually an alkyl or benzyl, m n is an integer of 2 to 10, X- denotes Br-, Cl-, I-,

CH

3 COO-, C 2

H

5 S03- or the like. However, the oligomers are not limited to these oligomers.

The oligomers usable in the second aspect of the present invention may be copolymers with monomer units having a nonionic pendant group.

0** With respect to the molecular weight distribution of *9 the cationic oligomers used in the second aspect of the present invention, the individual oligomers may be subjected to GPC measurement in advance. Alternatively, ,the molecular weight distribution may be determined in the 9- .e *following manner. Namely, after the molecular weight distribution of the liquid composition itself is determined, a sufficient amount of the ink containing the dye having at least an anionic group is mixed under stirring with the liquid composition in a beaker, and 0 17 1 precipitate formed is removed. Thereafter, the GPC measurement is conducted again to compare the measurement results before the mixing of the ink and after the mixing of the ink and the removal of the precipitate with each other, whereby the molecular weight distribution of the oligomer is found from the molecular weight distribution of the component precipitated by the dye in the ink and removed from the system.

In order to more enhance the effect of the present invention, such a cationic surfactant as mentioned below may be further contained in the liquid composition.

Specific examples of such a cationic surfactant include compounds of the primary, secondary and tertiary amine salt types, specifically, the hydrochlorides, S. 15 acetates and the like of laurylamine, coconut amine, stearylamine, rosin amine and the like; compounds of the so quaternary ammonium salt type, specifically, lauryl- S. trimethylammonium chloride, lauryldimethylbenzylammonium chloride, benzyltributylammonium chloride, benzalkonium chlorideand the like; pyridinium salt type compounds, specifically, cetylpyridinium chloride, cetylpyridinium bromide and the like; imidazoline type cationic compounds, specifically, 2-heptadecenyl-hydroxyethylimidazoline and the like; and ethylene oxide adducts of higher alkylamines, specifically, dihydroxyethylstearylamine and the like.

18 1 In the second aspect of the present invention, amphoteric surfactants exhibiting cationic properties in a certain pH region may also be used. More specifically, there are mentioned carboxylic acid type amphoteric surfactants, such as amino acid type amphoteric surfactants; compounds of the R-NH-CH 2

-CH

2 -COOH type; and betaine type compounds, specifically, stearyldimethylbetaine and lauryldihydroxyethylbetaine, and besides amphoteric surfactants of the sulfuric ester type, sulfonic acid type, phosphoric ester type and the like.

If these amphoteric surfactants are used, it goes without saying that the liquid composition must be adjusted either so as to have a pH not higher than their isoelectric point or so as to reach the pH not higher than the isoelectric 15 point when mixed with the ink on a recording medium.

Although the examples of the cationic compounds have been mentioned above, it goes without saying that compounds usable in the second aspect of the present invention are not always limited to these compounds.

The nonionic polymeric substance having a molecular weight of at least 2,000, which is another essential component to the liquid composition according to the second aspect of the present invention, will hereinafter be described. The action and effect of the nonionic polymeric substance in the present invention are also as described above. More specifically, as the second step of 19 1 the reaction of the liquid composition with the ink, the aggregates of the dye having the anionic group and the cationic oligomer formed by the association as the first step are adsorbed into its molecule to increase the size of the aggregates of the dye formed by the association so as to become difficult to enter the interfiber spaces of the recording paper, whereby the coloring material in the ink is left on the recording paper, and only the liquid component separated from the solid component is caused to penetrate into the recording paper to achieve the compatibility of print quality and fixing ability.

As specific examples of the nonionic polymeric substance exhibiting the action and effect as described above, may be mentioned nonionic water-soluble polymers, S 15 polyacrylamide, polyvinyl pyrrolidone, water-soluble cellulosics such as carboxymethylcellulose, hydroxymethylcellulose and hydroxypropylcellulose, polyvinyl methyl ether, polyvinyl acetal, and polyvinyl alcohol. It goes without saying that the polymeric substance is not limited to these polymeric substances. The effect of these polymeric substances in the practice of the present invention can be sufficiently exhibited so far as they have a molecular weight of at least 2,000. However, polymeric substances having a molecular weight of not lower than 2,000 but not higher than 10,000 may preferably be used.

1 In order to more enhance the effect of the present invention, a cationic polymeric substance may be used in combination with the nonionic polymeric substance described above in the second aspect of the present invention. As examples of the cationic polymeric substance used in this case, may be-mentioned polyallylamine hydrochloride, polyamine sulfone hydrochloride, polyvinylamine hydrochloride and chitosan acetate. It goes without saying that the cationic polymeric substance is not limited to these substances.

In the second aspect of the present invention, a compound obtained by partly cationizing a nonionic polymeric substance may be used as the cationic polymeric substance. As specific examples of such a compound, may 15 be mentioned copolymers of vinylpyrrolidone and an aminoalkylacrylate quaternary salt and copolymers of acrylamide and an aminomethylacrylamide quaternary salt.

45.0 It goes without saying that the compound is not limited to these compounds.

20 -If the above-described polymeric substances and the cationic polymeric substance are soluble in water, there is nothing to be said against them. However, they may be in the form of a dispersion such as latex or emulsion.

The amount of these components to be contained in 25 the liquid composition according to the second aspect of the present invention may preferably be within a range of 21 1 from 0.05 to 20 by weight, more preferably from 0.5 to by weight based on the total weight of the liquid composition. It is however necessary to determine an optimum range according to the combination of the individual substances to be used. The mixing ratio of the cationic oligomer to the nonionic polymeric substance in the liquid composition as described above is within a range of from 10:1 to 1:10, preferably from 5:1 to 1:5 by weight. If this ratio exceeds 10:1, the water fastness of the resulting print tends to be deteriorated. On the other hand, if the ratio is not lower than 1:10, the prevention of bleeding becomes insufficient, and so the edge sharpness of images formed tends to be reduced. It is hence not preferable to use these substances outside the above range of the mixing ratio.

The liquid composition according to the third aspect *s of the present invention will hereinafter be described.

09* The essential components to be contained in such a 0 liquid composition are as follows: (21) a low-molecular weight cationic substance having a molecular weight distribution in which at least one peak exists in a molecular weight region of not higher than 1,000, and (22) a cationic polymeric substance having a 0 molecular weight distribution in which at least one peak exists in a molecular weight region of not lower than 22 1 1,500.

On the other hand, the inks used in the present invention comprise: (23) a water-soluble dye having at least an anionic group, while other inks used in the present invention comprise: (24) a pigment and an anionic compound.

The action and effect of the above-described substances in the third aspect of the present invention are as described above. More specifically, the lowmolecular weight cationic substance of the component (21) in which the peak of the molecular weight distribution exists in a region of 1,000 or lower associates with the water-soluble dye of the component (23) having at least an anionic group, which is contained in the ink, or the anionic compound in the pigment ink owing to ionic interaction to form aggregates. The rate of this aggregate-forming reaction must be extremely fast.

900" Preferable specific examples of the low-molecular weight cationic substance of the component (21) in which 64 the peak of the molecular weight distribution exists in a region of 1,000 or lower are mentioned below.

Incidentally, a compound close to monodisperse in the 0, molecular weight distribution may often be used as the

B

low-molecular weight cationic substance in the third aspect of the present invention. With respect to a 23 1 compound having no molecular weight distribution, a usual molecular weight found from its chemical formula is considered as a position of the peak.

As preferable examples thereof, may be mentioned compounds of the primary, secondary and tertiary amine salt types, specifically, the hydrochlorides, the acetates and the like of laurylamine, coconut amine, stearylamine, rosin amine and the like, and besides compounds of the quaternary ammonium salt type, specifically, lauryltrimethylammonium chloride, lauryldimethylbenzylammonium chloride, benzyltributylammonium chloride, benzalkonium chloride, cetyltrimethylammonium chloride and the like, pyridinium salt type compounds, specifically, cetylpyridinium chloride, cetylpyridinium bromide and the like, imidazoline type cationic compounds, specifically, 2-heptadecenylhydroxyethylimidazoline and the like, and ethylene oxide adducts of secondary alkylamines, <specifically, dihydroxyethylstearylamine and the like.

In the third aspect of the present invention, amphoteric surfactants exhibiting cationic properties in a certain pH region may also be used.

*.4 More specifically, there are mentioned amino acid type amphoteric surfactants, compounds of the RNHCH 2

CH

2 COOH type, betaine type compounds, specifically, a stearyldimethylbetaine and lauryldihydroxyethylbetaine, and the like. If these amphoteric surfactants are used,

C

24 1 it goes without saying that the colorless or pale-colored liquid composition must be adjusted either so as to have a pH not higher than their isoelectric point or so as to reach the pH not higher than the isoelectric point when mixed with the ink on a recording medium.

Although the examples of the low-molecular weight cationic compounds have been mentioned above, it goes without saying that compounds usable in the third aspect of the present invention are not always limited to these compounds.

The action and effect of the cationic polymeric substance of the component (22) in which the peak of the molecular weight distribution exists in a region of not lower than 1,500 are as described above. More specifically, as the second step of the reaction of the i: liquid composition with the ink, the aggregates of the 908b 961 b .above-described dye or the anionic compound in the pigment ur, ink and the low-molecular weight cationic substance formed by the association are adsorbed into its molecule to increase the size of the aggregates of the dye or the Spigment formed by the association so as to become -difficult to enter the interfiber spaces of the recording paper, whereby only the liquid component separated from *094 the solid component is caused to penetrate into the r recording paper to achieve the compatibility of print 4 quality and fixing ability.

a0 4 25 1 As specific examples of the cationic polymeric substance of the component may be mentioned polyallylamine, polyamine sulfone, polyvinylamine, .chitosan, and neutralized products or partly neutralized products of these compounds with an acid such as hydrochloric acid or acetic acid. It goes without saying that the cationic polymeric substance is not limited to these substances. The effect of these polymeric substances in the practice of the present invention can be sufficiently exhibited so far as they have a molecular weight distribution in which at least one peak exists in a molecular weight region of not lower than 1,500.

However, polymeric substances having a molecular weight of not lower than 1,500 but not higher than 10,000 15 may be preferably used.

As other examples of the cationic polymeric substance of the component (22) used, may be mentioned Ce00 compounds obtained by partly cationizing a nonionic polymeric substance.

As specific examples of such compounds, may be mentioned copolymers of vinylpyrrolidone and an aminoalkylalkylate quaternary salt and copolymers of acrylamide and an aminomethylacrylamide quaternary salt.

It goes without saying that the compound is not limited to 25 these compounds.

*jt* 26 1 If the above-described cationic polymeric substances are soluble in water, there is nothing to be said against them. However, they may be in the form of a dispersion such as latex or emulsion.

The amount of these components to be contained in the colorless or pale-colored liquid composition may preferably be within a range of from 0.05 to 20 by weight, more preferably from 0.5 to 5 by weight based on the total weight of the liquid composition. It is however necessary to determine an optimum range according to the combination of the individual substances to be used. The mixing ratio of the low-molecular cationic substance of the component (21) to the polymeric substance of the component (22) in the liquid composition is within a range of from 10:1 to 1:10, preferably from 5:1 to 1:5 by weight. If this ratio exceeds 10:1, the water fastness of the resulting print tends to be deteriorated. On the other hand, if the ratio is not lower than 1:10, the prevention of bleeding becomes insufficient, and so the 20 edge sharpness of images formed tends to be reduced.

In the present invention, the use of the cationic 0. polymeric substance has more effects than the use of the nonionic polymeric substance from the viewpoint of the scoloring ability of dyes and pigments, ooo• 25 the resistance to bleeding in a region in which a shot-in ink quality is great, and water fastness under severer .0CC o 0 S ooCg.

27 1 conditions.

Other components making up the colorless or palecolored liquid compositions described above will then be described specifically.

The colorless or pale-colored liquid compositions are generally composed of water, a water-soluble organic solvent and other additives in addition to the abovedescribed respective components. As examples of the water-soluble organic solvent used include amides such as dimethylformamide and dimethylacetoamide, ketones such as acetone, ethers such as tetrahydrofuran and dioxane, polyalkylene glycols such as polyethylene glycol and polypropylene glycol, alkylene glycols such as ethylene glycol, propylene glycol, butylene glycol, triethylene glycol, thiodiglycol, hexylene glycol and diethylene glycol; 1,2,6-hexanetriol, lower alkyl ethers of polyhydric alcohols, such as ethylene glycol methyl ether, diethylene glycol monomethyl ether and triethylene glycol %fo. monomethyl ether, monohydric alcohols such as ethanol, 20 isopropyl alcohol, n-butyl alcohol and isobutyl alcohol, and besides, glycerol, N-methyl-2-pyrrolidone, 1,3dimethylimidazolidinone, triethanolamine, sulfolane and dimethyl sulfoxide.

No particular limitation is imposed on the content 25 of the water-soluble organic solvent. However, it may preferably be within a range of from 5 to 60 by weight,

SI

28 1 more preferably from 5 to 40 by weight based on the total weight of the liquid composition.

Besides the above components, additives such as a viscosity modifier, pH adjustor, antiseptic, surfactant, antioxidant and evaporation accelerator may be incorporated as needed. The selection of the surfactant is particularly important from the viewpoint of controlling the penetrability of the liquid composition.

The colorless or pale-colored liquid composition means a composition having a color tone which does not change the color tone of the recording inks. With respect to preferable physical property ranges at about 25 0 C of the colorless or pale-colored liquid compositions, the pH may be within a range of from 3 to 12, preferably from 3 to 8, more preferably from 3 to 5, the surface tension may be within a range of from 10 to 60 dyne/cm, preferably '"to 40 dyne/cm, and the viscosity may be within a range of r from 1 to 30 cP.

oe oooo Inks described in the present invention are commonly 99@9 20 used concurrently with the liquid composition in the first to third aspects mentioned above.

Then, the recording inks (type I) useful in the 4@.9 practice of the present invention according to an aspect of the present invention will hereinafter be described.

0@99 25 Besides a water-soluble dye having the anionic group described above, the recording inks (type I) used in the 0ooo *4 9 29 1 present invention comprise water and a water-soluble organic solvent, and optionally other components such as a viscosity modifier, pH adjustor, antiseptic, surfactant and antioxidant.

No particular limitation is imposed on the dyes having the anionic group used in the present invention so far as they are water-soluble acid dyes, direct dyes or reactive dyes, which are described in COLOR INDEX. Any dye not described in COLOR INDEX may also be used without any particular limitation so far as' it has an anionic group, for example, a sulfonic group or a carboxylic group. Among the water-soluble dyes used herein, those having dependence of solubility on pH are also included as a matter of course.

As the water-soluble organic solvent used in the inks, the water-soluble organic solvents used in the colorless or pale-colored liquid compositions as described above may be used similarly. The same shall apply to the preferable range of the content of the water-soluble 20 organic solvent. The preferable physical property ranges are exactly the same as those of the colorless or pale- .*"colored liquid compositions.

In order to more enhance the effects of the present invention, an anionic surfactant or an anionic polymeric 25 substance may be added to the inks in addition to the components described above. Alternatively, the above- 0 *r S P t 30 1 described amphoteric surfactant may also be used after adjusting it to a pH not lower than its isoelectric point.

As examples of the anionic surfactant used, may be mentioned those commonly used in inks, such as carboxylic acid salt type, sulfuric acid ester type and sulfonic acid salt type. As examples of the anionic polymeric substance, may be mentioned alkali-soluble resins, specifically, sodium polyacrylate and copolymers obtained by introducing an acrylic acid in a part of a polymer. It goes without saying that such compounds are not limited to these compounds.

Then, the recording inks (type II) useful in the practice of the present invention according to another aspect of the present invention will hereinafter be described.

P. Besides a pigment and an anionic compound, the recording inks (type II) comprise water and a watersoluble organic solvent, and optionally other components such as a viscosity modifier, pH adjustor, antiseptic, S 20 surfactant and antioxidant. In this aspect, the anionic compound may be a dispersant for the pigment, or if the dispersant for the pigment is not an anionic compound, an anionic compound may be used in addition to the dispersant. It goes without saying that even if the 25 dispersant is an anionic compound, another anionic compound may be added.

I. P -31- 1 No particular limitation is imposed on the pigments used in this aspect of the present invention.

Specifically, the following pigments may preferably be used.

First of all, as carbon black used in a black pigment ink, there may be used those produced in accordance with the furnace process or channel process and having a primary particle size of 15 to 40 nm, a specific surface area of 50 to 300 m 2 /g as determined in accordance with the BET method, an oil absorption of 40 to 150 ml/100 g as determined by using DBP, a volatile matter of 0.5 to and a pH of 2 to 9, for example, commerciallyavailable carbon black such as No. 2300, No. 900, MCF 88, No. 40, No. 52, MA 7, MA 8 and No. 2200 B (all, products of Mitsubishi Chemical Industries Limited), RAVEN 1255 (product of Columbian Carbon Japan Limited), REGAL 400R, REGAL 660R and MOGUL L (all, products of Cabot Company), and Color Black FW1, Color Black FW18, Color Black S170, g Color Black S150, Printex 35 and Printex U (all, products 20 of Degussa). Those newly prepared for the practice of the present invention may also be used. As examples of e pigments used in yellow, magenta and cyan inks, may be 9" mentioned C.I. Pigment Yellow 1, C.I. Pigment Yellow 2, C.I. Pigment Yellow 3, C.I. Pigment Yellow 13, C.I.

25 Pigment Yellow 16 and C.I. Pigment Yellow 83; Pigment Red 5, C.I. Pigment Red 7, C.I. Pigment Red 12, C.I.

32 1 Pigment Red 48 C.I. Pigment Red 48 C.I.

Pigment Red 57 C.I. Pigment Red 112 and C.I. Pigment Red 122; and C.I. Pigment Blue 1, C.I. Pigment Blue 2, C.I. Pigment Blue 3, C.I. Pigment Blue 15:3, C.I. Pigment Blue 16, C.I. Pigment Blue 22, C.I. Vat Blue 4 and C.I.

Vat Blue 6, respectively. However, those newly prepared for the practice of the present invention may also be used. The pigments as mentioned above may preferably be used within a range of from 1 to 20 by weight, more preferably from 2 to 12 by weight based on the total weight of their corresponding inks.

As the dispersant used in this aspect of the present invention, any resin may be used so far as it is soluble in water. However, the resin preferably has a weight average molecular weight ranging from 1,000 to 30,000, *I more preferably from 3,000 to 15,000. Specific examples thereof include block copolymers, graft copolymers and random copolymers composed of at least two monomers (at least one monomer being hydrophilic) selected from 20 hydrophobic monomers such as styrene, styrene derivatives, vinylnaphthalene, vinylnaphthalene derivatives and t aliphatic alcohol esters of a,/-ethylenically unsaturated carboxylic acids, acrylic acid, acrylic acid derivatives, maleic acid, maleic acid derivatives, itaconic acid, 25 itaconic acid derivatives, fumaric acid, and fumaric acid derivatives, and salts of these copolymers. These resins 33 1 are alkali-soluble resins which dissolve in an aqueous solution of a base. Besides, homopolymers composed of a hydrophilic monomer or salts thereof may be used.

Further, other water-soluble resins such as polyvinyl alcohol, carboxymethylcellulose and condensation products of naphthalene sulfonic acid and formaldehyde may also be used. However, the use of the alkali-soluble resin has an advantage in that the viscosity of the resultant dispersion can be made low, and moreover the pigment can be easily dispersed. The water-soluble resin may preferably be used in a range of from 0.1 to 5 by weight based on the total weight of the ink.

It is further desirable that the inks according to this aspect of the present invention is adjusted to neutrality or alkalinity, preferably, as the whole because the solubility of the water-soluble resin is enhanced, so S that an ink far excellent in long-term storability can be provided. It is more desirable that the pH be adjusted to a range of from 7 to Examples of the pH adjustor include various kinds of organic amines such as diethanolamine and triethanolamine, inorganic alkalis such as the hydroxides of alkali metals, for example, sodium hydroxide, lithium hydroxide, potassium hydroxide, etc., organic acids, and mineral 25 acids.

The pigment and water-soluble resin as described

*S

2r eo o em 34 1 above are dispersed or dissolved in'an aqueous medium.

An aqueous medium suitable for use in the inks (type II) according to this aspect of the present invention is a mixed solvent of water and a water-soluble organic solvent. As the water, it is preferable to use ionexchanged water (deionized water) instead of tap water containing various ions.

As examples of the water-soluble organic solvent used in combination with water, may be mentioned alkyl alcohols having 1 to 4 carbon atoms, such as methyl alcohol, ethyl alcohol, n-propyl alcohol, isopropyl alcohol, n-butyl alcohol, sec-butyl alcohol and tert-butyl alcohol; amides such as dimethylformamide and dimethylacetamide; ketones and ketone alcohols such as acetone and diacetone alcohol; ethers such as tetrahydrofuran and dioxane; polyalkylene glycols such as polyethylene glycol and polypropylene glycol; alkylene glycols the alkylene moiety of which has 2 to 6 carbon 9*9 atoms, such as ethylene glycol, propylene'glycol, butylene glycol, triethylene glycol, thiodiglycol, hexylene glycol and diethylene glycol; 1,2,6-hexanetriol; glycerol; lower .9 Salkyl ethers of polyhydric alcohols, such as ethylene glycol monomethyl (or monoethyl) ether, diethylene glycol methyl (or ethyl) ether and triethylene glycol monomethyl 25 (or monoethyl) ether; N-methyl-2-pyrrolidone; 2pyrrolidone; 1,3-dimethyl-2-imidazolidinone; and the like.

t* 35 1 Among a number of these water-soluble organic solvents, polyhydric alcohols such as diethylene glycol and lower alkyl ethers of polyhydric alcohols, such as triethylene glycol monomethyl (or monoethyl) ether are preferred.

In order to achieve good ejection stability, it is effective to add further ethanol or isopropyl alcohol in an amount of 1 or more because the addition of these solvents is considered to permit more stable bubbling of the recording ink on a thin film resistor. However, the addition of these solvents in excess involves a drawback that the print quality of the resulting print is impaired.

The suitable concentration of these solvents has been found to be 3 to 10 by weight. These solvent have a further effect that the addition of the solvents to the dispersion prevents foaming upon the preparation of the dispersion, thereby effectively conducting the dispersion.

The content of the water-soluble organic solvent in the ink according to this aspect of the present invention is generally within a range of from 3 to 50 preferably from 3 to 40 by weight based on the total weight of the ink, while the content of water used is within a range of from 10 to 90 by weight, preferably from 30 to 80 by weight based on the total weight of the ink.

If the dispersant is not an anionic polymer, an 25 anionic compound must be further added to the pigmentcontaining ink. As anionic compounds suitably used in

S

36 1 this aspect of the present invention, may be mentioned polymeric substances such as the alkali-soluble resins described as the dispersants for the pigments, and besides low-molecular weight anionic surfactants.

As specific examples of the low-molecular weight anionic surfactants, may be mentioned disodium lauryl sulfosuccinate, disodium polyoxyethylene lauroylethanolamide sulfosuccinate, disodium polyoxyethylene alkylsulfosuccinate, carboxylated polyoxyethylene lauryl ether sodium salt, carboxylated polyoxyethylene tridecyl ether sodium salt, sodium polyoxyethylene lauryl ether sulfate, triethanolamine polyoxyethylene lauryl ether sulfate, sodium polyoxyethylene alkyl ether sulfate, sodium alkylsulfate and triethanolamine alkylsulfate, to which, however, are not limited.

The suitable amount of the above-described anionic w: substances to be used is within a range of from 0.05 to by weight, more preferably from 0.05 to 5 by weight o based in the total weight of the ink.

Further, the inks according to this aspect of the present invention may contain, in addition to the above p components, a surfactant, antifoaming agent, antiseptic and the like as needed to provide them as inks having desired physical properties. Commercially-available 25 water-soluble dyes and/or the like may also be added thereto.

37 1 Examples of the surfactant include anionic surfactants such as fatty acid salts, salts of higher alcohol sulfates, salts of liquid fatty oil sulfates and alkylallylsulfonates; and nonionic surfactants such as polyoxyethylene alkyl ethers, polyoxyethylene alkyl esters, polyoxyethylene sorbitan alkyl esters, acetylene alcohol and acetylene glycol. These surfactants may be suitably chosen for either single use or combined use.

The amount of the surfactants to be used may vary according to the kind of the dispersant used. However, it may desirably be within a range of from 0.01 to 5 by weight based on the total weight of the ink. In this case, it is preferred that the amount of the surfactants added be determined in such a manner that the surface tension of the resulting ink is 30 dyne/cm or higher. If the surface tension is lower than this value, such an ink brings about undesirable situations such as slippage upon printing (defective ink-droplet impact) due to the wetting q on orifices in such a recording system as used in the present invention.

Each of the inks (type II) according to this aspect S..O of the present invention is prepared in the following manner. The pigment is first added to an aqueous solution containing at least the dispersant resin and water, and the mixture is stirred. A dispersion treatment is then conducted in accordance with a dispersing technique 38 1 described below, and if necessary, a centrifugation is carried out to obtain a desired dispersion. The components as mentioned above are then added to the dispersion. The resultant mixture is stirred to prepare the intended ink.

If the alkali-soluble resin is used, it is necessary to add a base for dissolving the resin in the dispersion.

It is also necessary to add the amine or base required to dissolve the resin in an amount at least once of the amount of the amine or base calculated out from the acid value of the resin. This calculated amount of the amine or base is found in accordance with the equation Amount of amine or base Acid value Molecular Amount of of resin weight of amine x resin (g) 5600 It is further preferable from the view point of improving the dispersion efficiency to conduct premixing en for at least 30 minutes prior to the dispersion treatment of the aqueous solution containing the pigment. This premixing serves to improve the wettability of the surface p* of the pigment and facilitate adsorption of the dispersant

*C

on the pigment surface.

In case the alkali-soluble resin is used, preferable 25 examples of the bases added to the dispersion include organic amines such as monoethanolamine, diethanolamine, 39 1 triethanolamine and aminomethylpropanol, ammonia, and inorganic bases such as potassium hydroxide and sodium hydroxide.

Any dispersing machine routinely used may be employed as a dispersing machine used in the present invention. As examples thereof, may be mentioned ball mills and sand mills.

Of these mills, high-speed sand mills are preferred.

Examples thereof include Super Mill, Sand Grinder, Beads Mill, Agitator Mill, Grain Mill, Dyno Mill, Pearl Mill, Coball Mill (all, trade names), etc.

No particular limitation is imposed on the recording medium used in the practice of the present invention, and the so-called plain paper such as paper for copying and bond paper, which are routinely used, are preferably used.

It goes without saying that coated paper specially prepared for ink-jet recording, and transparent films for S* OHP may also be suitably used, and besides general-purpose woodfree paper and glossy paper may also be suitably used.

Any method may be used as the image-forming method according to the present invention so far as it is a .Ol method in which the colorless or pale-colored liquid composition and the ink can be caused to coexist on a recording medium. No problem arises if either of the 25 liquid composition and the ink is first applied to the recording medium.

0 40 The term "image-forming region" as used herein means a region of a recording medium, to which dots of the ink are applied, while the term "the vicinity of the imageforming region" means an outside region about 1 to 5 dots away from the region to which dots of the ink are applied.

As a method of applying the colorless or palecolored liquid composition to the recording medium, it is considered to apply the liquid composition to the whole surface of the recording medium by a sprayer, roller or the like. However, the application is preferably carried out by an ink-jet system by which the liquid composition can be applied selectively and evenly only to the imageforming region where the ink will be applied, and the vicinity of the image-forming region.

No particular limitation is imposed on the time required from the time the liquid composition is applied ro~ to the recording medium up to the time the ink is then *Vwo -o applied. In order to carry out the present invention more .66.

effectively, however, it is preferable to apply the ink 6696 within several seconds, particularly preferably, within 1 second. The same shall apply to the case where the ink is first applied to a recording medium, and the colorless or pale-colored liquid composition is then applied.

*6.9 As the method of applying the colorless or paleer S" 25 colored liquid composition to the recording medium, °664 various kinds of ink-jet recording systems may be used.

6 41 1 However, the so-called On-Demand type thermal ink-jet system in which bubbles generated by thermal energy are used to eject droplets is particularly preferred.

Recording apparatus useful in the practice of the present invention will then be described. In the present invention, the so-called On-Demand type thermal ink-jet system in which a recording signal is applied to a recording ink in a recording head to eject droplets of the ink by the thermal energy generated is preferred.

Examples of the construction of a recording head, which is a main component of such an apparatus, are illustrated in Figs. i, 2 and 3.

A head 13 is formed by bonding a glass, ceramic, plastic plate or the like having an ink-passing channel to a heating head 15, which is used for thermal recording and has a heating resistor (the drawing shows a head to which, 0e..

however, is not limited). The heating head 15 is composed es of a protective film 16 made of silicon oxide or the like, aluminum electrodes 17-1 and 17-2, a heating resistor layer 18 made of nichrome or the like, a heat accumulating layer 19, and a substrate 20 made of alumina or the like A bo having a good heat radiating property.

A recording ink 21 comes up to an ejection orifice 6.66 22 and forms a meniscus 23 owing to a pressure P.

25 Now, upon application of electric signals to the electrodes 17-1, 17-2, the heating head 15 rapidly 42 1 generates heat at the region shown by n to form bubbles in the ink 21 which is in contact with this region. The meniscus 23 of the ink is projected by the action of the pressure thus produced, and the ink 21 is ejected from the orifice 22 to a recording medium 25 in the form of recording droplets 24.' Fig. 3 schematically illustrates a multi-head-- composed of an array of a number of heads as shown in Fig. 1. The multi-head is formed by closely bonding a glass plate or the like 27 having a number of channels to a heating head 28 similar to the head as illustrated in Fig. 1.

Incidentally, Fig. 1 is a cross-sectional view of the head 13 taken along the flow path of the ink, and Fig. 2 is a cross-sectional view taken along line 2-2' in Fig. 1.

Fig. 4 illustrates an exemplary ink-jet recording apparatus in which such a head has been incorporated.

&few In Fig. 4, reference numeral 61 designates a blade -r serving as a wiping member, one end of which is a stationary end held by a blade-holding member to form a cantilever. The blade 61 is provided at a position @0 adjacent to a region in which a recording head operates, and in this embodiment, is held in such a form that it protrudes to the course through which the recording head 25 is moved. Reference numeral 62 indicates a cap, which is -provided at a home position adjacent to the blade 61, and a 0 43 1 is so constituted that it moves in a direction perpendicular to a direction in which the recording head is moved and comes into contact with the face of ejection openings to cap it. Reference numeral 63 denotes an inkabsorbing member provided adjoiningly to the blade 61 and, similar to the blade 61, held in such a form that it protrudes to the course through which the recording head is moved. The above-described blade 61, cap 62 and absorbing member 63 constitute an ejection-recovery portion 64, where the blade 61 and absorbing member 63 remove water, dust and/or the like from the face of the ink-ejecting openings.

Reference numeral 65 designates the recording head having an ejection-energy-generating means and serving to eject the ink onto a recording medium set in an opposing relation with the ejection opening face provided with ejection openings to conduct recording. Reference numeral 66 indicates a carriage on which the recording head 65 is co* mounted so that the recording head 65 can be moved. The 20 carriage 66 is slidably interlocked with a guide rod 67 and is connected (not illustrated) at its part to a belt

CC

Sbe 69 driven by a motor 68. Thus, the carriage 66 can be 0 moved along the guide rod 67 and hence, the recording head 65 can be moved from a recording region to a region 25 adjacent thereto.

Reference numerals 51 and 52 denote a paper feeding *0 e• 44 1 part from which the recording media are separately inserted, and paper feed rollers driven by a motor (not illustrated), respectively. With such construction, the recording medium is fed to the position opposite to the ejection opening face of the recording head, and discharged from a paper discharge section provided with paper discharge rollers 53 with the progress of recording.

In the above constitution, the cap 62 in the head recoyery portion 64 is receded from the moving course of the recording head 65 when the recording head 65 is returned to its home position, for example, after completion of recording, and the blade 61 remains protruded to the moving course. As a result, the ejection opening face of the recording head 65 is wiped. When the cap 62 comes into contact with the ejection opening face of the recording head 65 to cap it, the cap 62 is moved so as to protrude to the moving course of the recording head.

C*

When the recording head 65 is moved from its home see position to the position at which recording is started, *so.

20 the cap 62 and the blade 61 are at the same positions as fO 0 the positions upon the wiping as described above. As a sees result, the ejection opening face of the recording head is also wiped at the time of this movement.

The above movement of the recording head to its home 25 position is made not only when the recording is completed or the recording head is recovered for ejection, but also osee* e• 5555 S S OeeS

S*

45 45 1 when the recording head is moved between recording regions for the purpose of recording, during which it is moved to the home position adjacent to each recording region at given intervals, where the ejection opening face is wiped in accordance with this movement.

Fig. 5 illustrates an exemplary ink cartridge in which an ink to be fed to the head through an ink-feeding member, for example, a tube is contained. Here, reference numeral 40 designates an ink container portion containing the ink 'to be fed, as exemplified by a bag for the ink.

One end thereof is provided with a stopper 42 made of rubber. A needle (not illustrated) may be inserted into this stopper 42 so that the ink in the bag 40 for the ink can be fed to the head. Reference numeral 44 indicates an ink absorbing member for receiving a waste ink.

It is preferable that the ink container portion is formed of a polyolefin, in particular, polyethylene, at its surface with which the ink comes into contact.

0000 The ink-jet, recording apparatus used in the present 0000 0000 20 invention may not be limited to the apparatus as described 0**o above in which the head and the ink cartridge are

A*

separately provided. Therefore, a device in which these members are integrally formed as shown in Fig. 6 can also be preferably used.

In Fig. 6, reference numeral 70 designates a rin recording unit, in the interior of which an ink container o• 0 0 0@ @000 46 1 portion containing an ink, for example, an ink-absorbing member, is.contained. The recording unit 70 is so constructed that the ink in such an ink-absorbing member is ejected in the form of ink droplets through a head 71 having a plurality of orifices. For example, polyurethane may be used as a material for the ink-absorbing member.

Reference numeral 72 indicates an air passage for communicating the interior of the recording unit 70 with the atmosphere. This recording unit 70 can be used in place of the recording head shown in Fig. 4, and is detachably installed on the carriage 66. Incidentally, in the recording apparatus used in the present invention, the ink-jet recording apparatus in which thermal energy is applied to an ink to eject droplets of the ink has been described by way of example. However, the present invention can also be used in other ink-jet recording apparatus such as a piezo-system using a piezoelectric element.

In the case where the image-forming process 20 according to the present invention is carried out, for example, a recording apparatus in which five recording heads, each of which has been illustrated in Fig. 3, are arranged on a carriage 80, is used. An example thereof is illustrated in Fig. 7. Reference numerals 81, 82, 83 and 84 indicate recording heads for ejecting inks of yellow, o**O magenta, cyan and black colors, respectively. Reference t o 47 1 numeral 85 designates a head for ejecting the liquid composition. The heads are arranged in the abovedescribed recording apparatus and serve to eject the respective recording inks of the different colors according to recording signals. Before the ejection of the inks, the liquid composition is applied in advance to at least portions of recording paper where the recording inks of the different colors are to apply thereto. Fig. 7 shows the case where the five recording heads have been used. However, the present invention is not limited thereto. As shown in Fig. 8, preference is given even to the case where the flow paths of the yellow, magenta, cyan and black inks and the liquid composition are separately provided in one recording head.

It goes without saying that construction of the head may be changed so as to reverse the recording order of the liquid composition and the inks as described above The present invention will hereinafter be described s* 0,0o more specifically by the following examples and 20 comparative examples. Incidentally, all designations of "part" or "parts" and as will be used in the following examples mean part or parts by weight and by weight unless expressly noted.

Examples 1 to 42: 25 [Preparation of Colorless or Pale-colored Liquid Composition] 0

S**

48 1 The following respective components were mixed into solutions, and the resultant solutions were then filtered under pressure through a membrane filter (Fluoropore Filter, trade name: product of Sumitomo Electric Industries, Ltd.) having a pore size of 0.22 pm, thereby obtaining colorless or pale-colored Liquid Compositions

I

A

through I

H

pHs of the Liquid Compositions I A to I H were adjusted by treating the respective solutions with NaOH or HC1 after the preparation thereof.

Composition of Liquid Composition

IA:

Benzyltri-n-butylammonium chloride 1.5 parts (product of Tokyo Kasei Kogyo Co., Ltd.) Sanflock N-500P (polyacrylamide, 0.5 part product of Sanyo Chemical Industries, Ltd.) Thiodiglycol 10 parts Deionized water 88 parts pH of I A Composition of Liquid Composition

IB:

Benzalkonium chloride (product of 0.5 parts 20 Sanyo Chemical Industries, Ltd.) P olyacrylamide (synthesized in our 3.0 partscompany) Thiodiglycol 10 parts Deionized water 86.5 parts 25 pH of IB 4.8.

Composition of Liquid Composition IC: 4 4 'i *444 4 .4 i 4 .4 444 4 4. 4 *444 4 .4.

44444 4 4 4p** 4. 4 491 1 Benzalkonium chloride (product of.

Sanyo Chemical Industries, Ltd.) Polyvinyl alcohol (synthesized in our company, Mw 2,500, complete saponification) Thiodiglycol Deionized water pH of I C 4.8.

Composition of Liquid Composition

ID:

Benzalkonium chloride (product of Sanyo Chemical Industries, Ltd.) Polyvinyl alcohol (synthesized in our company, Mw 9,000, complete saponification) Thiodiglycol Deionized water pH of I D 4.9.

Composition of Liquid Composition

IE:

Benzalkonium chloride (product of 20 Sanyo Chemical Industries, Ltd.) Polyvinyl alcohol (synthesized in our company, Mw 26,000, complete saponification) Thiodiglycol 25 Deionized water pH of IE 1.5 parts 10 parts 10 parts 78.5 parts 1.5 parts 5 parts 10 parts 83.5 parts 1.5 parts 1 part 10 parts 87.5 parts 0 4400

S

4. 0 Or 5 55 0* 0S S

S

0 50 SComposition of Liquid Composition IF: Benzalkonium chloride (product of Sanyo Chemical Industries, Ltd.) PVP K-15 (product of International Specialty Chemicals, Mw 7,000) Thiodiglycol Deionized water pH of I F Composition of Liquid Composition IG: .0 Levon TM-16 (cetyltrimethylammonium chloride, product of Sanyo Chemical Industries, Ltd.) PVP K-15 (product of International Specialty Chemicals, Mw 7,000) Thiodiglycol Deionized water pH of I G Composition of Liquid Composition

IH:

Levon 15 (sodium alkyl diaminoethyl- 20 glycinate, the alkyl group is a lauryl group, product of Sanyo Chemical Industries, Ltd.) PVP K-15 (product of International Specialty Chemicals, Mw 7,000) 25 Thiodiglycol Deionized water 1.5 parts 5 parts 10 parts 83.5 parts 3.0 parts 3 parts 10 parts 84.0 parts 1.5 parts 3 parts 10 parts 85.5 parts ease S.

S

9 9* .9 59 *5 5

C

51 1 pH of IH 3.2.

[Preparation of Recording Ink] (Preparation of Recording Ink 11) The following respective components were mixed into solutions, and the resultant solutions were filtered under pressure through a membrane filter (Fluoropore Filter, trade name: product of Sumitomo Electric Industries, Ltd.) having a pore size of 0.22 pm, thereby obtaining Recording Ink 11 composed of yellow, magenta, cyan and black inks.

Yellow Ink Y1 of Recording Ink 11: C.I. Direct Yellow 86 2 parts Thiodiglycol 10 parts Acetylenol EH (EO adduct of acetylene 0.05 part glycol, product of Kawaken Fine Chemicals Co., Ltd.) Deionized water 87.95 parts.

Cyan Ink C11 of Recording Ink 11: The same composition as that of Yellow Ink Y1 1 except that C.I. Direct Yellow 86 in Y1 1 was changed to 20 2.5 parts of C.I. Direct Blue 199, and the amount of deionized water was changed to 87.45 parts.

Magenta Ink M11 of Recording Ink 11 The same composition as that of Cyan Ink Cl 1 except that C.I. Direct Blue 199 in C1 1 was changed to 2.5 parts 25 of C.I. Acid Red 289.

Black Ink Bkl of Recording Ink 11 52 1 The same composition as that of Magenta Ink M11 except that 2.5 parts of C.I. Acid Red 289 in Y1 1 were changed to 4.0 parts of C.I. Food Black 2, and the amount of deionized water was changed to 85.95 parts.

(Preparation of Recording Ink 12) Recording Ink 12 composed of inks Y1 2 M12, C12 and Bkl 2 having yellow, magenta, cyan and black colors, respectively, was prepared in exactly the same manner as in the preparation of Recording Ink 11 composed of Y1 1 M11, C11 and Bkl except that a styrene-acrylic acid copolymer (Johncryl 61J, trade name, product of Johnson Company, Ltd., Mw 10,000) was added in an amount of part to the respective inks of Recording Ink 11, and the amount of deionized water in each ink was controlled in such a manner that the total amount of the ink amounted to 100 parts.

(Preparation of Recording Ink 13) Recording ink 13 composed of inks Y1 3 M13, C1 3 and Bkl 3 having yellow, magenta, cyan and black colors, o. 20 respectively, was prepared in exactly the same manner as in the preparation of Recording Ink 11 composed of Y1 1 M1l, C11 and Bkl except that an anionic surfactant (Emal D, trade name, product of Kao Corporation, sodium lauryl sulfate) was added in an amount of 1.0 part to the 25 respective inks of Recording Ink 11, and the amount of deionized water in each ink was controlled in such a 53 1 manner that the total amount of the ink amounted to 100 parts.

(Preparation of Recording Ink 14) Yellow Ink Y14 of Recording Ink 1 An alkali-soluble resin (styrene-acrylic acid-ethyl acrylate; acid value: 160; weight average molecular weight: 8,000) was used as a dispersant to prepare the following dispersion for a yellow ink. Incidentally, monoethanolamine was used as a neutralizer for the alkalisoluble resin.

Aqueous alkali-soluble resin 35 partssolution P1 1 (solids content: 20 C.I. Pigment Yellow 86 24 parts Triethylene glycol 10 parts Diethylene glycol 10 parts Ethylene glycol monobutyl ether 1.0 part Isopropyl alcohol 0.5 part Deionized water 135 parts.

The above components were charged in a batch-wise 20 vertical sand mill (manufactured by Aimex Company), and

C

glass beads having a diameter of 1 mm were charged as a grinding medium to conduct a dispersion treatment for 3 hours while cooling with water. The dispersion was 9' centrifuged to remove coarse particles, thereby obtaining 25 a dispersion having an average particle size of 100 pm.

After 100 parts of deionized water were added to the 54 1 dispersion, the mixture was thoroughly stirred to obtain Yellow Ink Y1 4 of pH Cyan Ink C14 of Recording Ink 14: The same aqueous alkali-soluble resin solution P1 1 as that used in the preparation of Y1 4 was used. After the following components were mixed, a dispersion treatment was conducted under the same conditions as in the preparation of Y1 4 Aqueous alkali-soluble resin 30 parts solution P1 1 (solids content: 20 C.I. Pigment Blue 15:3 24 parts Triethylene glycol 10 parts Diethylene glycol 10 parts Ethylene glycol monobutyl ether 1.0 part Isopropyl alcohol 3 parts Deionized water 135 parts.

The thus-obtained dispersion had an average particle size of 120 nm.

After 100 parts of deionized water were added to the 20 dispersion, the mixture was thoroughly stirred to obtain Cyan Ink C1 4 of pH 9.2.

4 Magenta Ink M14 of Recording Ink 14 The same aqueous alkali-soluble resin solution P1 1 as that used in the preparation of Y1 4 was used. After 25 the following components were mixed, a dispersion treatment was conducted under the same conditions as in S o.

55 1 the preparation of Y1 4 Aqueous alkali-soluble resin 20 parts solution P1 1 (solids content: 20 C.I. Pigment Red 122 24 parts Glycerol 15 parts Isopropyl alcohol 3 parts Deionized water 135 parts.

The thus-obtained dispersion had an average particle size of 115 nm.

After 100 parts of deionized water were added to the dispersion, the mixture was thoroughly stirred to obtain Magenta Ink M1 4 of pH 9.4.

Black Ink Bkl 4 of Recording Ink 14: The following components were mixed and heated to 70°C on a water bath, thereby completely dissolving a resin.

Styrene-acrylic acid-ethyl acrylate 1.5 parts copolymer (acid value: 160; weight average molecular weight: 8,000) 20 Monoethanolamine 1.2 parts -Deionized water 81.5 parts.

To this solution, were added 10 parts of carbon black (MCF 88, product of Mitsubishi Chemical Industries Limited)- and 1 part of isopropyl alcohol to premix them 25 for 30 minutes. Thereafter, the resultant premix was subjected to a dispersion treatment under the following

U,.

*c ti..

i-S 999 9*.

'Se.

S 5 5., 5 9. 5C 9, 0S 99 5 S .9 95*5 01 56 1 conditions: Dispersing machine: Sand Grinder (manufactured by Igarashi Kikai K.K.) .Grinding medium: zirconiumbeads Packing rate of the grinding medium: (by volume) Grinding time: 3 hours.

The dispersion was further subjected to a centrifugal treatment (12,000 rpm, 20 minutes) to remove coarse particles into a dispersion.

The following components were then mixed to obtain Black Ink Bkl 4 of pH Dispersion described above 30 parts Glycerol 10 parts Ethylene glycol 5 parts N-Methylpyrrolidone 5 parts Isopropyl alcohol 2 parts Deionized water 48 parts.

(Preparation of Recording Ink 20 Inks of yellow, magenta, cyan and black colors were prepared in exactly the same manner as in the preparation of Recording Ink 14 except that the dispersant in Recording Ink 14 was changed to an equiamount of polyvinyl pyrrolidone PVP K-15 (product of International Specialty 25 Chemicals, Mw 7,000).

Then, an anionic surfactant (Emal D, trade name, *9B& *0

B

57 1 product of Kao Corporation, sodium lauryl sulfate) was added to the thus-obtained inks in a proportion of part per 100 parts of the respective inks, and the resultant mixtures were thoroughly mixed, thereby obtaining Recording Ink 15 composed of inks Y1 5 M1 5 and Bkl 5 having yellow, magenta, cyan and black colors, respectively.

Using the combinations of the thus-obtained liquid compositions and recording inks as ink sets, recording was then conducted on Canon PPC paper. As an ink-jet recording apparatus, was used a recording apparatus similar to that shown in Fig. 4. Color images were formed using 5 recording heads as illustrated in Fig. 7.

Incidentally, the individual recording heads used had a recording density of 360 dpi, and were driven with a drive frequency of 5 kHz. In view of the ejection volume per dot, heads from which an ink can be ejected at a rate of 40 pl/dot was used for the yellow, magenta and cyan inks and the liquid compositions, while a head from which an 20 ink can be ejected at a rate of 80 pl/dot was used for the black inks using a dye as a coloring material, or a head from which an ink can be ejected at a rate of 60 pl/dot was used for the black inks using a pigment as a coloring material.

25 Printing was performed in accordance with the combinations of the colorless or pale-colored liquid wo 58 compositions and the recording inks and their printing order shown in Table 1.

Table 1 Liquid Example composition Ink Printing process 1 IA 11 Ejecting I A first 2 I A 11 Ejecting IA later 3 IB 11 Ejecting I B first 4 IB 11 Ejecting Ig later IB 14 Ejecting I B first 6 IB 14 Ejecting Ig later 7 I C 11 Ejecting I C first 8 IC 11 Ejecting I C later 9 I C 14 Ejecting I C first IC 14 Ejecting I C later 11 ID 11 Ejecting I D first 12 I D 11 Ejecting I D later 13 ID 14 Ejecting I D first 14 ID 14 Ejecting I D later IE 11 Ejecting I E first 16 IE 11 Ejecting I E later 17 IE 14 Ejecting I E first 18 IE 14 Ejecting I

E

later b

S

S*

S~

1 .1 59 Table 1 (Cont'd) SLiquid Example composition Ink Printing process 19 IF 11 Ejecting I F first IF 11 Ejecting I F later 21 IF 12 Ejecting I F first 22 I F 12 Ejecting I F later 23 I F 13 Ejecting I F first 24 IF 13 Ejecting I F later IF 14 Ejecting I F first 26 I F 14 Ejecting I F later 27 I F 15 Ejecting I F first 28 IF 15 Ejecting I F later 29 I G 11 Ejecting I G first IG 11 Ejecting IG later 31 IG 12 Ejecting IG first 32 IG 12 Ejecting I G later 33 IG 13 Ejecting I G first 34 I G 13 Ejecting I G later 35 I G 14 Ejecting I G first 36 IG 14 Ejecting I G later 37 I G 15 Ejecting I G first 38 I G 15 Ejecting I G later 39 IH 11 Ejecting I H first 40 IH 11 Ejecting I H later 41 IH 14 Ejecting I H first 42 IH 14 Ejecting IH later

B-BB

.B C@ Brr

B

B.

B. B,

B

B

B

60 1 The resultant recorded images were evaluated in accordance with the following methods.

1. Image density: After a solid image was formed with the combination of the liquid composition and the black ink in each ink set and left over for 12 hours, its reflection density was measured by a reflection densitometer, Macbeth RD915 (manufactured by Macbeth Company) and ranked in accordance with the following standard: AA: Reflection density was not lower than 1.30; A: Reflection density was not lower than 1.25 but lower than 1.30; B: Reflection density was not lower than 1.15 but lower than 1.25; C: Reflection density was lowerthan 1.15.

2. Fixing ability: o.va After a solid print image of a red color was formed e g.

with the combination of the liquid composition and the sea* yellow and magenta inks in each ink set, another white C 20 paper sheet was placed on the recorded image by its own weight, thereby measuring the time required until the recorded image no longer transferred to the back side of °S the paper sheet and no greasing occurred assuming that the 4**C time the recording was completed was zero. The time 25 measured was used as a measure of the fixing ability to rchi P rank it in accordance with the following standard:

C

61 1 AA: Shorter than 20 seconds; A: Not shorter than 20 but shorter than 30 seconds; B: Not shorter than 30 but shorter than 40 seconds; C: Not shorter than 3. Quality of character: Black English characters and numerals were printed with the combination of the liquid composition and the black ink in each ink set to visually evaluate the quality y of character. The quality of character was ranked as AA where feathering was scarcely conspicuous, A where feathering was somewhat conspicuous, but no problem arose from the viewpoint of practical use, or C where the level was lower than the above.

4. Resistance to bleeding: solid print images of yellow, magenta, cyan and black colors were printed in contiguity with one another with the combinations of the liquid composition and the yellow, magenta, cyan and black inks in each ink set in accordance with the same printing mode as the printing *S04 20 mode E (1 pass, one-direction printing) in a Color Bubble Jet Printer BJC-820 (trade name, manufactured by Canon Inc.), thereby visually observing the degree of bleeding at portions of boundaries between the inks of different colors. The resistance to bleeding was ranked as AA where 25 bleeding scarcely occurred, A where bleeding slightly occurred, but no problem arose from the viewpoint of

O*

62 1 practical use, or C where the level was lower than the above.

Water fastness: After solid print images and English characters and numerals of yellow, magenta, cyan and black colors were printed with the combinations of the liquid composition and the yellow, magenta, cyan and black inks in each ink set, and the resulting print samples were left over for 1 hour, they. were immersed for O10 seconds in tap water of 20 0 C. Thereafter, they were taken out of the water, and filter paper was lightly pressed against the print samples to remove water from the surfaces of the-recorded images.

The print samples were then air-dried as they are to visually evaluate the images in water fastness. Among the yellow, magenta, cyan and black inks, the ink poorest in water fastness was taken as the evaluation result of water fastness. The water fastness was ranked in accordance i with the following standard: IlVIVO a AA: No ink running toward the blank portionfof the *aaa 20 recording medium occurred, greasing was scarcely recognized, and blurring of the English characters and numerals also scarcely occurred; A: Ink running toward the blank portion of the SW Sq recording medium slightly occurred, and the 25 English characters and numerals were somewhat bb paoi blurred, but no problem arose from the viewpoint a

~S~

63 1 of practical use; C: Ink running toward the blank portion of the recording medium occurred to a significant extent, greasing was also markedly recognized, and marked blurring of the English characters and numerals also occurred.

In all the above examples and following comparative examples, a region of the recording medium, to which the liquid composition is applied, corresponds to the imageforming region with the inks. The printing duty is 100 in each of the liquid compositions and the inks. The results of the evaluation as to the print samples in Examples 1 to 42 are shown collectively in Table 2.

Comparative Examples 1 to Printing tests and evaluation were performed in exactly the same manner as in Examples 1 to 42 except that *e> Inks 11 to 15 were separately used, but no liquid composition was used. The results are shown in Table 3.

Comparative Example 6: 20 A colorless or pale-colored Liquid composition 0eO composed of the following components was prepared, and printing tests and evaluation were conducted in the same

S.

manner as in Examples 1 to 42 except that this liquid composition and the same inks as those used in Example 1 25 were used.

Benzyltributylammonium chloride 1.5 parts

S.

64 Thiodiglycol Surfactant (Acetylenol EH, product of Kawaken Fine Chemicals Co., Ltd.) Deionized water The results are shown in Table 3.

Table 2 10 parts 0. 5 part 88 parts

L*&

of.a 0 000 040 E. Image -Fixing Quality of Resistance Water density ability character to bleeding fastness 1 A A A A A 2- A A A A A 3 AA AA AA AA A 4 AA A A A A AA A AA AA AA 6 AA A A AA j AA 7 AA AA AA AA A 8 AA A A AA 9 AA A AA AA AA 10 AA A A AA AA 11 AA AA AA AA A 12 AA A A A AA 13 AA A AA AA AA 14- AA A A AA A A 'A A -A

A

16 A A A A A 17 A A AA AA AA 18 A A, A AA AA 65 Table 2 (Corit'd) Image Fixing Quality of Resistance Water EX. density ability character to bleeding fastness 19 AA AA AA AA AA A A A A 21 AA A A AA AA 22 AA A A AA AA 23 A-A AA AA AA AA 24 AA AA A AA AA AA A AA AA AA 26 AA A A AA AA 27 AA AA AA AA AA 28 AA AA AA A AA 29 AA A AA AAA AA A A A A 31 AA A AA AA AA 32 AA A A A AA 33' AA AA, AA AA AA 34 AA AA A A AA 35 AA A AA AA AA 36 AA A A AA AA 37 AA AA AA AA AA 38 AA AA A AA AA 39 A AA AA AA A 40 A AA A A A 41 AA A AA AA AA 42 AA I A A AA i AA

SS

0 0* 0000

S

0@00 0 0 00 0 00 0 S 00 0600 00 *0 S 0000 0 *c 00 0 SOS. Oj 0

SO..

0 0* '0 5 0 0 66 1 Table 3 9* 9@SS 0*S@ *5 0eI* 9 fe e0* 5**

S

S. 0* 9.

9 0 OS 0

S

Comp. Image Fixing Quality of Resistance Water Ex. density ability character to bleeding fastness 1 AA B AA C C 2 AA B AA C C 3 B AA C C C 4 C C AA C AA C C AA C AA 6 B B C C C The present invention will.hereinafter be described in more detail by other examples and comparative examples.

Incidentally, the weight average molecular weights of the dispersants in the pigment inks in the following examples were determined by the GPC method using a styrene polymer as a standard.

Example 43: The following components were first mixed into a solution, and the resultant solution was then filtered under pressure through a membrane filter (Fluoropore Filter, trade name: product of Sumitomo Electric Industries, Ltd.) having a pore size of 0.22 pm, thereby obtaining a colorless Liquid Composition IIA the pH of which was adjusted to 4.8.

Components of Liquid Composition IIA: Polyallylamine hydrochloride 5.0 parts 67 1 (peak of molecular weight distribution in terms of polyoxyethylene oxide: 800) Nonionic polymer, PVP-K-15 5.0 parts (polyvinyl pyrrolidone, Mw 7,000) Thiodiglycol 10.0 parts Deionized water 80.0 parts.

(Preparation of Ink 21) The following respective components were then mixed into solutions, and the resultant solutions were separately filtered under pressure through a membrane filter (Fluoropore Filter, trade name: product of Sumitomo Electric Industries, Ltd.) having a pore size of 0.22 pm, thereby obtaining a yellow ink Y2 1 a magenta ink M2 1 a cyan ink C2 1 and a black ink Bk2 1 which were adjusted to pH 4.8 and contained their corresponding dyes having an anionic group. These inks were called Ink 21 collectively.

Yellow Ink Y21: C.I. Direct Yellow 86 2 parts Thiodiglycol 10 parts EO adduct of acetylene glycol 0.05 part (Acetylenol EH, product of Kawaken Fine Chemicals Co., Ltd.) Deionized water 87.95 parts.

25 Magenta Ink M2 C.I. Acid Red 289 2.5 parts 68 1 Thiodiglycol 10 parts EO adduct of acetylene glycol 0.05 part (Acetylenol EH, product of Kawaken Fine Chemicals Co., Ltd.) Deionized water 87.45 parts.

Cyan Ink C2 1 C.I. Direct Blue 199 2.5 parts Thiodiglycol 10 parts EO adduct of acetylene glycol 0.05 part (Acetylenol EH, product of Kawaken Fine Chemicals Co., Ltd.) Deionized water 87.45 parts.

Black Ink Bk21: C.I. Food Black 2 4.0 parts Thiodiglycol 10 parts EO adduct of acetylene glycol 0.05 part (Acetylenol EH, product of Kawaken Fine Chemicals Co., Ltd.) Deionized water 85.95 parts.

Using, as an ink set, the combination of the thusobtained Liquid Composition II A and Ink 21 according to goo this example, recording was then conducted on PPC paper (product of Canon Inc.). As an ink-jet recording apparatus, was used a recording apparatus similar to that S 25 shown in Fig. 4. Color images were formed using recording heads as illustrated in Fig. 7. In this '904, S0 SO 69 1 recording, Liquid Composition II A was first ejected to apply it to the recording paper in advance, after which Ink 21 was applied. Incidentally, individual recording heads used in this example had a recording density of 360 dpi, and were driven with a drive frequency of 5 kHz. In view of the ejection volume per dot, heads from which an ink can be ejected at a rate of 40 pl/dot was used for the yellow, magenta and cyan inks and the liquid composition, while a head from which an ink can be ejected at a rate of 80 pl/dot was used for the black ink.

Incidentally, these recording conditions are the same throughout examples and comparative examples, which will be described subsequently and use inks containing a dye. The environmental conditions upon printing tests were controlled to 25 0 C and 55 RH.

Example 44: Recording was conducted under the same conditions as those in Example 43 except that the combination of Liquid .Composition IIA and Ink 21 using a dye as a coloring material, which had'been used in Example 43, was used as an ink set according to this example, and Ink 21 was first applied to the recording paper and Liquid Composition IIA was then ejected.

Example *oo S 25 Liquid Composition IIB of this example composed of the following components was first prepared in the same 5 S Se 4, 70 1 manner as in the preparation of Liquid Composition IIA according to Example 43.

Components of Liquid Composition IIB: Cationic oligomer represented by 5.0 parts the following formula (peak of molecular weight distribution in terms of polyoxyethylene oxide: 900) (C2H40)mH

C

18

H

37

-N-CH

2

C

6

H

*W

9 99** 6..

9 9 *09@ 9 9. 9 9 99 .9*9 (C2H40)nH Nonionic polymer, PVP-K-15 5.0 parts (polyvinyl pyrrolidone, Mw 7,000) Thiodiglycol 10.0 parts Deionized water 80.0 parts.

(Preparation of Ink 22) Ink 22 composed of inks Y2 2 M2 2 C22 and Bk2 2 having yellow, magenta, cyan and black colors, respectively, and containing their corresponding dyes having an anionic group was prepared in the same manner as in the preparation of Ink 21 of Example 43 except that an anionic polymeric substance (Johncryl 61J, styrene-acrylic acid copolymer, Mw 10,000, product of Johnson Company, Ltd.) was added in an amount of 1.0 part to the respective 25 components of Ink 21 used in Example 43, and the amount of water in each ink was controlled in such a manner that the 71 1 total amount of the components amounted to 100 parts.

Using, as an ink set, the combination of the thusprepared Liquid Composition IIB and Ink 22 according to this example, recording was then conducted on PPC paper (product of Canon Inc.) under the same conditions as in Example 43. In this example, also, Liquid Composition

IIB

was first ejected to apply it to the recording paper in advance, after which Ink 22 was applied to conduct the recording.

Example 46: Recording was conducted under the same conditions as those in Example 43 except that the combination of Liquid Composition IIB and Ink 22 using a dye as a coloring material, both, used in Example 45, was used as an ink set according to this example, and Ink 22 was first applied to

S.

the recording paper and Liquid Composition II was then e** ejected.

i Example 47:

C

too Liquid Composition IIC of this example composed of 5 the following components was first prepared in the same manner as in the preparation of Liquid Composition

IIA

i according to Example 43.

Components of Liquid Composition IIC: Polyallylamine hydrochloride 5.0 parts S 25 (peak of molecular weight distribution in terms of polyoxyethylene oxide: 800) o* C 72 1 Nonionic polymer, PVP-K-15 5.0 parts (polyvinyl pyrrolidone, Mw 7,000) Thiodiglycol 10.0 parts Benzalkonium chloride represented by 3.0 parts the following formula

[CI

2

H

2 5-N (CH3CH) H 2 C1 Deionized water 77.0 parts.

Using, as an ink set, the combination of the thusprepared Liquid Composition II C according to this example, and Ink 21 using a dye as a coloring material, which had been used in Example 43, recording was then conducted on PPC paper (product of Canon Inc.) under the same conditions as in Example 43. In this example, also, Liquid Composition II c was first ejected to apply it to the recording paper in advance, after which Ink 21 was applied to conduct the recording.

Example 48: Recording was conducted under the same conditions as those in Example 43 except that the combination of Liquid Composition II c and Ink 21 using a dye as a coloring material, both, used in Example 47, was used as an ink set

S**

according to this example, and Ink 21 was first applied to the recording paper and Liquid Composition II c was then ejected.

S 25 Example 49: Recording was conducted under the same conditions as 73 1 those in Example 43 except that the combination of Liquid Composition II c used in Example 47, and Ink 22 using a dye as a coloring material, which had been used in Example was used as an ink set according to this example, and Liquid Composition II c was first applied to the recording paper and Ink 22 was then applied.

Example Recording was conducted under the same conditions as those in Example 43 except that the combination of Liquid Composition II c used in Example 47, and Ink 22 using a dye as a coloring material, which had been used in Example was used as an ink set according to this example, and Ink 22 was first applied to the recording paper and Liquid Composition IIC was then ejected.

Example 51: Recording was conducted under the same conditions as those in Example 43 except that the combination of Liquid Composition IIC used in Example 47, and Ink 23 using a dye .o as a coloring material and obtained in the following manner was used as an ink set according to this example, and Liquid Composition IIC was first applied to the

S*

recording paper and Ink 23 was then applied.

(Preparation of Ink 23) Ink 23 composed of inks Y2 3 M2 3 C2 3 and Bk2 3 S 25 having yellow, magenta, cyan and black colors, respectively, and containing their corresponding dyes 74 1 having an anionic group was prepared in the same manner as in the preparation of Ink 21 of Example 43 except that an anionic surfactant (Emal D, sodium lauryl sulfate, product of Kao Corporation) was added in an amount of 1.0 part to the respective components of Ink 21 used in Example 43, and the amount of deionized water in each ink was controlled in such a'manner that the total amount of the components amounted to 100 parts.

Example 52: Recording was conducted under the same conditions as those in Example 43 except that the combination of Liquid Composition IIc used in Example 47, and Ink 23 using a dye as a coloring material, which had been used in Example 51, was used as an ink set according to this example, and Ink 23 was first applied to the recording paper and Liquid Composition II C was then ejected.

Example 53: Liquid Composition IID of this example composed of

C

the following components was first prepared in the same manner as in the preparation of Liquid Composition II

A

according to Example 43.

Components of liquid composition IID: Cationic oligomer represented by 5.0 parts 0 ,the following formula (peak of molecular weight distribution in terms of polyoxyethylene oxide: 900) e 75 1 (C 2

H

4 0)mH 18

H

3 7

-N-CH

2

C

6

H

(C

2

H

4 0)nH Nonionic polymer, PVP-K-15 5.0 parts (polyvinyl pyrrolidone, Mw 7,000) Thiodiglycol 10.0 parts Benzalkonium chloride represented by 3.0 parts the following formula

[C

1 2

H

2 5 -N (CH 3 2

CH

2 ]Cle Deionized water 77.0 parts.

Using, as an ink set, the combination of the thusprepared liquid composition IID according to this example, and Ink 21 using a dye as a coloring material, which had been used in Example 43, recording was then conducted on PPC paper (product of Canon Inc.) under the same conditions as in Example 43. In this example, also, Liquid Composition IID was first ejected to apply it to fo. the recording paper in advance, after which Ink 21 was applied to conduct the recording.

Example 54: a.

Recording was conducted under the same conditions as those in Example 43 except that the combination of Liquid Composition IID and Ink 21 using a dye as a coloring 25 material, both, used in Example 53, was used as an ink set according to this example, and Ink 21 was first applied to ip 76 1 the recording paper and Liquid Composition IID was then ejected.

Example Recording was conducted under the same conditions as those in Example 43 except that the combination of Liquid Composition IID used in Example 53, and Ink 22 using a dye as a coloring material, which had been used in Example was used as an ink set according to this example, and Liquid Composition IID was first applied to the recording paper and Ink 22 was then applied.

Example 56: Recording was conducted under the same conditions as those in Example 43 except that the combination of Liquid Composition IID used in Example 53, and Ink 22 using a dye as a coloring material, which had been used in Example was used as an ink set according to this example, and Ink **0 22 was first applied to the recording paper and Liquid *0 Composition IID was then ejected.

Example 57: Recording was conducted under the same conditions as Sthose in Example 43 except that the combination of Liquid Composition IID used in Example 53, and Ink 23 using a dye as a coloring material, which had been used in Example 51, was used as an ink set according to this example, and 00609: 25 Liquid Composition IID was first applied to the recording paper and Ink 23 was then applied.

*S

77 1 Example 58: Recording was conducted under the same conditions as those in Example 43 except that the combination of Liquid Composition IID used in Example 53, and Ink 23 using a dye as a coloring material, which had been used in Example was used as an ink set according to this example, and Ink 23 was first applied to the recording paper and Liquid Composition IID was then ejected.

Example 59: Inks Y2 4 M2 4 C2 4 and Bk2 4 having yellow, magenta, cyan and black colors, respectively, and containing their corresponding pigments and an anionic compound were prepared in the following manner. These inks were called Ink 24 collectively. An ink set of this example was 15 prepared from Ink 24 and Liquid Composition II c used in #9 Example 47. Using this ink set, recording was conducted O• on PPC paper (product of Canon Inc.). In this example, 9~9* Liquid Composition IIC was first ejected to apply it to *the recording paper in advance, after which Ink 24 was applied to conduct the recording.

Individual recording heads used in this example had a recording density of 360 dpi, and were driven with a drive frequency of 5 kHz. In view of the ejection volume per dot, heads from which an ink can be ejected at a rate of 40 pl/dot was used for the yellow, magenta and cyan inks and the liquid composition, while a head from which 0 78 1 an ink can be ejected at a rate of 60 pl/dot was used for the black ink.

Incidentally, these recording conditions are the.

same throughout examples, which will be described subsequently and use inks containing a pigment. The environmental conditions upon printing tests were controlled to 25*C and 55 RH.

(Preparation Ink 24) Black Ink Bk24: (Preparation of pigment dispersion) Styrene-acrylic acid-ethyl acrylate 1.5 parts copolymer (acid value: 140, weight average molecular weight: 5,000) Monoethanolamine 1 part 15 Diethylene glycol 5 parts 0 4 SDeionized water 81.5 parts ,ooo The above components were mixed, and heated to 70 0

C

0000 on a water bath to completely dissolve the resin. To this solution, were added 10 parts of carbon black (MCF 88, product of Mitsubishi Chemical Industries Limited) and 1 part of isopropyl alcohol to premix them for 30 minutes.

Thereafter, the resulting premix was subjected to a dispersion treatment under the following conditions: Dispersing machine: Sand Grinder (manufactured by Igarashi Kikai K.K.) Gu Grinding medium: zirconium beads (diameter: 1 mm) 79 1 Packing rate of the grinding medium: (by volume) Grinding time: 3 hours.

The dispersion was further subjected to a centrifugal treatment (12,000 rpm, 20 minutes) to remove coarse particles into a dispersion.

(Preparation of black ink) The above-prepared dispersion was used, and components of the following compositional proportion were mixed to prepare an ink containing the pigment, thereby providing this ink as Black Ink Bk2 4 Dispersion described above 30.0 parts Glycerol 10.0 parts Ethylene glycol 5.0 parts 15 N-Methylpyrrolidone 5.0 parts a* U Isopropyl alcohol 2.0 parts Deionized water 48.0 parts.

Yellow Ink Y2 4 4 Yellow Ink Y2 4 containing a pigment was prepared in the same manner as in the preparation of Black Ink Bk2 4 except that 10 parts of carbon black (MCF 88, product of Mitsubishi Chemical Industries Limited) used in the #to preparation of Black Ink Bk2 4 were changed to Pigment e* Yellow 74.

Magenta Ink M24: *ae Magenta Ink M2 4 containing a pigment was prepared in 80 1 the same manner as in the preparation of Black Ink Bk2 4 except that 10 parts of carbon black (MCF 88, product of Mitsubishi Chemical Industries Limited) used in the preparation of Black Ink Bk2 4 were changed to Pigment Red 7.

Cyan Ink C2 4 Cyan Ink C2 4 containing a pigment was prepared in the same manner as in the preparation of Black Ink Bk2 4 except that 10 parts of carbon black (MCF 88, product of Mitsubishi Chemical Industries Limited) used in the preparation of Black Ink Bk2 4 were changed to Pigment Blue Example Recording was conducted under the same conditions as S. 15 those in Example 59 except that the combination of Liquid Composition IIC used in Example 47, and Ink 24 using a pigment as a coloring material, which had been used in Example 59, was used as an ink set according to this example, and Ink 24 was first applied to the recording paper and Liquid Composition II C was then ejected.

Example 61: t Recording was conducted under the same conditions as those in Example 59 except that the combination of Liquid Composition IID used in Example 53, and Ink 24 using a pigment as a coloring material, which had been used in Example 59, was used as an ink set according to this 81 1 example, and Liquid Composition IID was first applied to the recording paper and Ink 24 was then applied.

Example 62: Recording was conducted under the same conditions as those in Example 59 except that the combination of Liquid Composition IID used in Example 53, and Ink 24 using a pigment as a coloring material, which had been used in Example 59, was used as an ink set according to this example, and Ink 24 was first applied to the recording paper and Liquid Composition IID was then ejected.

[Evaluation] The recorded images obtained in Examples 43 to 62, which are summarized in Table 4, were evaluated in accordance with the methods described above. The results 15 are shown collectively in Table see a*s see 9 a a o

U.

82 Table 4 Example Liquid Ik Pitn rcs composition Ik Pitn rcs "3IA 21 Ejecting "IA first 44"A 21 Ejecting "IA later 22 Ejecting JIB f irst 46 "IB 22 Ejecting "IB later 47 I 21 Ejecting IIC first 48 11 c 21 'Ejecting I1 later 9II 22 Ejecting C first C 22 Ejecting IIc later 51 IIc 23 Ejecting IIC first 52 IID 23 Ejecting "ID later 21 Ejecting IID first 54 ID21 Ejecting IID later 22 Ejecting IID first 56 "ID 22 Ejecting "ID later 23 Ejecting IID first 58 "ID 23 Ejecting "ID later 59 IC24 Ejecting IIC first 60 IeC 24 Ejecting IIC later 61 "ID 24 Ejecting IID first 62 ID- 24 Ejecting IID later 0* 0 0e0 0000 0 00 a0 0 83 Table 5 Evaluation results Ex.

Image density Fixing ability Quality of character Resistance, to bleeding Water fastness 43 AA A AA A AA 44 AA A A A A AA AA AA AA AA 46 AA AA A A A 47 A AA AA AA A 48 A NA A A A 49 NA NA NA NA A NA NA A A A 51 A NA A NA A 52 A NA A A A 53 A AA A NA NA 54 A NA NA A A 55 NA NA A NA A 56 NA NA A A A 57 A NA A NA A 58 A NA A A A 59 AA A NA NA A 60 NA A NA A A 61 ANA A NA NA A 62 NA A NA A A As apparent from Table 5, images excellent in all the fixing ability, quality of character, image density, 0* 9 0eOO OeeS 9 S. S.

5555

S

s..

0@S* S e S@ S 55 S 0 @5 S S 55 0 0500

S

9S @0 050 0 0 0 0500 S 05

S

S

84 1 resistance to bleeding and water fastness were obtained in the examples, while only images low in the density and poor in the quality of character were provided in Comparative Example 6. These images were poor even in the water fastness.

Example 63: Using Liquid Composition II A used in Example 43 and 3 inks of Yellow Ink Y2 1 Magenta Ink M21 and Cyan Ink C2 1 in Ink 21 used in Example 43, a solid print image was recorded with each duty controlled to 100 thereby forming an image of the so-called process black. The conditions for the printing were exactly the same as those in Example 43. In this case, the results of the evaluation as to the image density, fixing ability, quality of character and bleeding at portions of \o boundaries between the image of the process black and images of other colors were all good. Therefore, it was confirmed that the present invention is effective.

The present invention will hereinafter be described in more detail by further examples and comparative .0999 examples.

Examples 64 to 109: .9 9 [Preparation of colorless of pale-colored liquid composition] The following respective components were mixed into solutions, and the resultant solutions were then filtered

S

.1 85 1 under pressure through a membrane filter (Fluoropore Filter, trade name: product of Sumitomo Electric Industries, Ltd.) having a pore size of 0.22 pm, thereby obtaining colorless or pale-colored Liquid Compositions IIIA through

III

G

Composition of Liquid Composition

IIIA:

Stearyltrimethylammonium chloride 2 parts (Electrostripper QE, trade name, product of Kao Corporation) Polyamine sulfone hydrochloride 10 parts (PAS-A-1, trade name, product of Nitto Boseki Co., Ltd., peak of molecular weight distribution: 2,000) Thiodiglycol 10 parts Deionized water 78 parts.

Composition of Liquid Composition IIIB: Stearyltrimethylammonium chloride 2 parts (Electrostripper QE, trade name, **o product of Kao Corporation) Polyamine sulfone hydrochloride 6 parts (PAS-A-5, trade name, product of Nitto Boseki Co., Ltd., peak of molecular weight distribution: 3,500) Thiodiglycol 10 parts Deionized water 82 parts.

Composition of Liquid Composition

IIIC:

86 1 Stearyltrimethylammonium chloride 2 parts (Electrostripper QE, trade name, product of Kao Corporation) Polyamine sulfone hydrochloride 4 parts (PAS-92, trade name, product of Nitto Boseki Co., Ltd., peak of molecular weight distribution: 5,000) Thiodiglycol 10 parts Deionized water 84 parts.

Composition of Liquid Composition IIID: Stearyltrimethylammonium chloride 2 parts (Electrostripper QE, trade name, product of Kao Corporation) Polyallylamine hydrochloride 3 parts (synthesized in our company, peak of molecular weight distribution: 8,500) Thiodiglycol 10 parts Deionized water 85 parts.

The polyallylamine was synthesized in accordance with the method described in "Kino Zairyo (Functional Material)", Vol. 5, 29 (1986). The same shall apply to the following examples.

Composition of Liquid Composition IIIE: .Polyallylamine 3 parts (synthesized in our company, peak of molecular weight distribution: 800) 87 1 Polyamine sulfone hydrochloride 10 parts (PAS-A-1, trade name, product of Nitto Boseki Co., Ltd., peak of molecular weight distribution: 2,000) Thiodiglycol 10 parts Deionized water 77 parts.

The polyallylamine oligomer was also synthesized in accordance with the method described in "Kino Zairyo (Functional Material)", Vol. 5, 29 (1986). The same shall apply to the following examples.

Composition of Liquid Composition

IIIF:

Polyallylamine 5 parts (synthesized in our company, peak of molecular weight distribution: 650) Polyallylamine hydrochloride 3 parts (synthesized in our company, peak of molecular weight distribution: 8,500) 9** Thiodiglycol 10 parts Deionized water 82 parts.

Composition of Liquid Composition

IIIG:

Behzyltri-n-butylammonium chloride 3 parts (product of Tokyo Kasei Kogyo Co., Ltd., reagent grade) too.

Polyallylamine hydrochloride 3 parts (synthesized in our company, peak of i molecular weight distribution: 8,500) 9 9 88 1 Thiodiglycol 10 parts Deionized water 84 parts.

[Preparation of Recording Ink] (Preparation of Recording Ink 31) The following respective components were mixed and then filtered under pressure through a membrane filter (Fluoropore Filter, trade name: product of Sumitomo Electric Industries, Ltd.) having a pore size of 0.22 pm, thereby obtaining Recording Ink 31 composed of yellow, magenta, cyan and black inks.

Yellow Ink Y31 of Recording Ink 31 C.I. Direct Yellow 142 2 parts Thiodiglycol 10 parts Acetylenol EH (EO adduct of acetylene 0.05 part glycol, product of Kawaken Fine Chemicals Co., Ltd.) Deionized water 87.95 parts.

Cyan Ink C31 of Recording Ink 31 The same composition as that of Yellow Ink Y3 1 20 except that C.I. Direct Yellow 142 in Y3 1 was changed to parts of C.I. Direct Blue 199, and the amount of deionized water was changed to 87.45 parts.

Magenta Ink M31 of Recording Ink 31: The same composition as that of Cyan Ink C3 1 except 25 that C.I, Direct Blue 199 in C3 1 was changed to 2.5 parts of C.I. Acid Red 92.

a.

a a.

a..

a. pa pa a aa p a p a

S

-p 89 1 Black Ink Bk3 1 of Recording Ink 31 The same composition as that of Magenta Ink M31 except that 2.5 parts of C.I. Acid Red 92 in M3 1 were changed to 4.0 parts of C.I. Food Black 2, and the amount of deionized water was changed to 85.95 parts.

(Preparation of Recording Ink 32) Recording Ink 32 composed of inks Y3 2 M3 2 C32 and Bk3 2 having yellow, magenta, cyan and black colors, respectively, was prepared in exactly the same manner as in the preparation of Recording Ink 31 of Y3 1 M3 1 C31 and Bk3 1 except that a styrene-acrylic acid copolymer (Johncryl 61J, trade name, product of Johnson Company, Ltd., Mw 10,000) was added in an amount of 0.5 part to the respective inks of Recording Ink 31, and the amount of deionized water in each-ink was controlled in such a ago* manner that the total amount of the ink amounted to 100 parts.

(Preparation of Recording Ink 33) Recording ink 33 composed of inks Y3 3 M3 3 C3 3 and Bk3 3 having yellow, magenta, cyan and black colors, respectively, was prepared in exactly the same manner as in the preparation of Recording Ink 31 of Y3 1 M3 1 C31 and Bk3 1 except that an anionic surfactant [Viewlight ESS, trade name, product of Sanyo Chemical Industries, Ltd., 9 disodium polyoxyethylene aikyl(C 12

-C

16 )sulfosuccinate was added in an amount of 1.0 part to the p 90 1 respective inks of Recording Ink 31, and the amount of deionized water in each ink was controlled in such a manner that the total amount of the ink amounted to 100 parts.

(Preparation of Recording Ink 34) Yellow Ink Y34 of Recording Ink 34: An alkali-soluble resin (styrene-acrylic acid-ethyl acrylate; acid value: 160; weight average molecular weight: 8,000) was used as a dispersant to prepare the following dispersion for a yellow ink. Incidentally, monoethanolamine was used as a neutralizer for the alkalisoluble resin.

Aqueous alkali-soluble resin 35 parts solution P3 1 (solids content: 20 C.I. Pigment Yellow 83 24 parts .Triethylene glycol 10 parts Diethylene glycol 10 parts Ethylene glycol monobutyl ether 1.0 part Isopropyl alcohol 0.5 part Deionized water 135 parts.

The above components were charged in a batch-wise vertical sand mill (manufactured by Aimex Company), and glass beads having a diameter of 1 mm were charged as a grinding medium to conduct a dispersion treatment for 3 hours while cooling with water. The dispersion was centrifuged to remove coarse particles, thereby obtaining 1 i 91 1 a dispersion having an average particle size of 100 nm.

After 100 parts of deionized water were added to the dispersion, the mixture was thoroughly stirred to obtain Yellow Ink Y3 4 of pH Cyan Ink C34 of Recording Ink 34: The same aqueous alkali-soluble resin solution P3 1 as that used in the preparation of Y3 4 was used. After the following components were mixed, a dispersion treatment was conducted under the same conditions as in the preparation of Y3 4 Aqueous alkali-soluble resin 30 parts solution P3 1 (solids content: 20 C.I. Pigment Blue 15:3 24 parts Triethylene glycol 10 parts 15 Diethylene glycol 10 parts Ethylene glycol monobutyl ether 1.0 part Isopropyl alcohol 3 parts Deionized water 135 parts.

**re The thus-obtained dispersion had an average particle size of 120 nm.

After 100 parts of deionized water were added to the dispersion, the mixture was thoroughly stirred to obtain Cyan Ink C3 4 of pH 9.2.

Magenta Ink M34 of Recording Ink 34 4 The same aqueous alkali-soluble resin solution P3 1 *as that used in the preparation of Y34 was used. After as that used in the preparation of Y3 4 was used. After 9 92 1 the following components were mixed, a dispersion treatment was conducted under the same conditions as in the preparation of Y3 4 Aqueous alkali-soluble resin 20 parts solution P31 (solids content: 20 Pigment Red 122 24 parts Glycerol 15 parts Isopropyl alcohol 3 parts Deionized water 135 parts.

The thus-obtained dispersion had an average particle size of 115 nm.

After 100 parts of deionized water were added to the dispersion, the mixture was thoroughly stirred to obtain Magenta Ink M3 4 of pH 9.4.

S. 15 Black Ink Bk34 of Recording Ink 3 The following components were mixed and heated to 70*C on a water bath, thereby completely dissolving a S resin.

Styrene-acrylic acid-ethyl acrylate 1.5 parts copolymer (acid value: 160; weight average molecular weight: 8,000) 1 Monoethanolamine 1.2 parts Deionized water 81.5 parts.

To this solution, were added 10 parts of carbon 25 black (MCF 88, product of Mitsubishi Chemical Industries 9* Limited) and 1 part of isopropyl alcohol to premix them 93 1 for 30 minutes. Thereafter, the resultant premix was subjected to a dispersion treatment under the following conditions: Dispersing machine: Sand Grinder (manufactured by Igarashi Kikai K.K.) Grinding medium: zirconium beads Packing rate of the grinding medium: (by volume) Grinding time: 3 hours.

The dispersion was further subjected to a centrifugal treatment (12,000 rpm, 20 minutes) to remove coarse particles into a dispersion.

The following components were then mixed to obtain Black Ink Bk3 4 of Recording Ink 34 having a pH of 15 Dispersion described above 30 parts fe* Glycerol 10 parts Ethylene glycol 5 parts N-Methylpyrrolidone 5 parts Isopropyl alcohol 2 parts De'ionized water 48 parts.

(Preparation of Recording Ink 1 Inks of yellow, magenta, cyan and black colors were prepared in exactly the same manner as in the preparation of Recording Ink 34 except that the dispersant in 25 Recording Ink 34 was changed to an equiamount of polyvinyl .S pyrrolidone PVP K-15 (product of International Specialty 94 1 Chemicals, Mw 7,000).

Then, an anionic surfactant [Viewlight ESS, trade name, product of Sanyo Chemical Industries, Ltd., disodium polyoxyethylene alkyl(C 1 2

-C

1 6 )sulfosuccinate was added to the thus-obtained inks in a proportion of part per 100 parts of the respective inks, and the resultant mixtures were thoroughly mixed, thereby obtaining Recording Ink 35 composed of inks Y3 5 M3 5 C3 and Bk3 5 having yellow, magenta, cyan and black colors, respectively.

Using the combinations of the thus-obtained liquid compositions and recording inks as ink sets, recording was then conducted on Canon PPC paper. As an ink-jet recording apparatus, was used a recording apparatus 15 similar to that shown in Fig. 4. Color images were formed using 5 recording heads as illustrated in Fig. 7.

Incidentally, the individual recording heads used had a recording density of 360 dpi, and were driven with a drive frequency of 5 kHz. In view of the ejection volume per dot, heads from which an ink can be ejected at a rate of 40 pl/dot was used for the yellow, magenta and cyan inks and the liquid compositions, while a head from which an ink can be ejected at a rate of 80 pl/dot was used for the black inks using a dye as a coloring material, or a head 25 from which an ink can be ejected at a rate of 60 pl/dot was used for the black inks using apigment as a coloring was used for the black inks using a pigment as a coloring 11 11 1 95 1 material.

The printing was performed in accordance with the combinations of the colorless or pale-colored liquid compositions and the recording inks and their printing order shown in Table 6.

Table 6 i.

*i

S

S. -r 5

S

8O a

S

S

S.

15 Example Liquid Ink Printing process composition 64 IIIA 31 Ejecting IIIA first IIIA 31 Ejecting IIIA later 66 IIIA 34 Ejecting IIIA first 67 IIIA 34 Ejecting IIIA later 68 III B 31 Ejecting III B first 69 III B 31 Ejecting IIIB later 70 III B 34 Ejecting IIIB first 71 III B 34 Ejecting IIIB later 72 IIIC 31 Ejecting IIIc first 73 III C 31 Ejecting IIIC later 74 III C 34 Ejecting IIIC first 75 III C 34 Ejecting III C later 76 IIID 31 Ejecting IIID first 77 III D 31 Ejecting III D later 78 IIID 34 Ejecting IIID first 79 III

D

34 Ejecting IIID later 96 Table 6 (Cont'd) Example Liquid Ink Printing process composition IIIE 3 1 Ejecting "'IE first 81 "'IE 31* Ejctng"E later 82 IIIE 32 Ejecting IIIE first 83 "'IE 32 Ejecting IIIE later 84, IIE 33 Ejecting "'IE first IIIE 33 Ejecting IIIE later 86 IIIE 34 Ejecting IIIE first 87 IIIE 34 Ejecting "'IE later 88 IIIE 35 Ejecting 'IE first 89 IIIE 35 Ejecting IIIE later "'IF 31 Ejecting "'IF first 91 "'IF 31 Ejecting "'IF later 92 "'IF 32 Ejecting "'IF first 93IIF 32 Ejecting "'IF later 33 Ejecting "'IF first 33 Ejecting "'IF later 96"F34 Ejecting "'IF first 97'IF 34 Ejecting "'IF later 98 "IF. 35 Ejecting "'IF first 35 Ejecting I"'IF lat er 4.4. 4. 6~e S. *5 0 4.060

S

*Se.

*004

S

4.5*.

~O94.

4.9 Sg U S e,~ *9.4.

Oh

S

5000

U

4..

4.

9.4.5w.

S

4.0.4.4.

4.

S.

8. 4.

8.

97 Table 6 (Cont'd) Example Liquid Ink Printing process composition 100 IIIG 3, Ejecting III G first 101 IILG 3 1 Ejecting IIIG later 102 IIIG 32 Ejecting III G first 103 IIIG 32 Ejecting IIIG later 104 III G 33 Ejecting IIIG first 105 III G 33 Ejecting III G later 106 III G 34 Ejecting IIIG first 107 III G 34 Ejecting III G later 108 III G 35 Ejecting IIIG first 109 III G 35 Ejecting III G later 15 The resultant recorded images were evaluated in accordance with the methods described above. The results are shown collectively in Table 7.

Comparative Example 7 to 11: Printing test and evaluation were performed in exactly the same manner as in Examples 1 to 42 except that Inks 31 to 35 were separately used, but no liquid composition was used. The results are shown in Table 8.

.r 'eig *0 p, a. eq

U

a a. a) a a ar r a 0 0 0 98 Table 7 E.Image Fixing Quality of Resistance Water E.density ability character to bleeding fastness 64 AA AA AA AA AA AA AA A AA AA 66 AA AA AA AA AA 67 AA AA, AA AA AA 68 AA AA-- AA AA AA 69 AA AA A AA AA AA AA AA AA AA 71 AA AA AA AA AA 72 AA AA AA AA AA 73 AA AA A AA AA 74 AA AA- AA AA AA AA AA AA AA AA 76 AA AA AA AA AA 77 AA AA AA AA AA 78 AA AA A AA AA 79 AA AA AA AA AA 0e

S

06v *Oae *00 99 Table 7 (Cont'd) E.Image .Fixing Quality ofj Resistance Water x.density ability character to bleeding fastness AA A AA AA AA 81 AA- A A AA AA 82 AA A AA AA AA 83 AA A AA AA AA 84 AA AA AA AA AA AA AA A AA AA 86 AA A AA AA AA 87 AA A AA AA AA 88 AA AA AA AA AA 89 AA AA AA AA AA AA A AA AA AA 91 'AA A AAA. AA 92 AA A A.A AA AA 93 AA A AA AA AA 94 AA AA A AA AA 95 AA AA AA AA AA 96 AA A AA. AA AA 97 AA A AA AA AA 98 AA AA AA AA AA 99 AA AA AA AA AA 9* 4e.e 5.S Se..

CUSS

0 0 00 S C S 05 5005

S.

CS S *Sf~0

S

egOS

S

5e0050 0 55'0 S C S 55@5 S. 05 .0 0 S S 100 Table 7 (Cont'd) Ex.

Image density Fixing ability Quality of character Resistance to bleeding.

Water fastness 66 6 6666 i 6666 6066 6 0606 6606 6 *600 6 0 66 0 66 6 6 66 0660 9 9 0 66 6 *0p6 9 6666 6 66666.

6 6666 6 *666 66 66 6 6 100 AA A AA AA AA 101 AA A A AA AA 102 AA A AA AA AA 103 AA A AA AA AA 104 AA AA AA AA AA 105 AA AA A AA AA 106, AA A AA AA AA 107 AA A AA AA AA 108 AA AA AA AA AA 109 AA AA AA AA AA Table 8 Comp. Image Fixing Quality of Resistance Water Ex. density ability character to bleeding fastness 7 AA B AA C C 8 AA B AA C C 9 B AA C CC 10 CC AA C AA 11 C C AA C AA As has been described above, the practice of the present invention permits the provision of images satisfying high-speed fixing, high print quality, 101 1 resistance to bleeding and perfect water fastness even when conducting color ink-jet recording on plain paper.

While the present invention has been described with respect to what is presently considered to be the preferred embodiments, it is to be understood that the invention is not limited to the disclosed embodiments. To the contrary, the invention is intended .to cover various modifications and equivalent .arrangements included within the spirit and scope of the appended claims. The scope of the following claims is to be accorded to the broadest interpretation so as to encompass all such modifications and equivalent structures and functions.

9**S s9' 9 e

Claims (43)

1. A liquid composition for use in an ink-jet image forming process with an ink containing an anionic dye or an anionic compound and a pigment, and for use in an ink- jet ejecting process, comprising a cationic substance and a nonionic polymeric substance, the liquid composition reacting with the ink to cause the anionic dye or anionic compound in the ink to aggregate when the liquid composition contacts with the ink, wherein the cationic substance has a weight average molecular weight of at most 1,000, and the nonionic polymeric substance has a weight average molecular weight of at least 2,000.

2. The liquid composition according to claim 1, wherein the cationic substance and the nonionic polymeric substance are contained in the liquid composition in a range of from 0.05 to 20% by weight in total.

3. The liquid composition according to claim 1 or claim 2, wherein the cationic substance is a surfactant.

4. The liquid composition according to any one of the preceding claims, wherein the mixing ratio of the cationic substance to the nonionic polymeric substance is within a range of from 10:1 to 1:10 by weight. The liquid composition according to any one of the preceding claims, wherein the cationic substance has a weight average molecular weight of from 100 to 700.

6. The liquid composition according to any one of the preceding claims, wherein the pH of the liquid composition is from 3 to 12.

7. The liquid composition according to claim 6, wherein the pH is from 3 to 8.

8. A liquid composition for use in an ink-jet image forming process with an ink containing an anionic dye or an anionic compound and a pigment,, and for use in an ink- 25 jet ejecting process, comprising a cationic oligomer having a weight average molecular weight distribution in which a peak exists when being measured by GPC method, and a, nonionic polymeric substance, wherein the cationic oligomer reacts with the anionic dye or anionic compound in the ink to cause the anionic dye or anionic compound to aggregate when the liquid 30 composition contacts with the ink, and wherein the peak exists in -the weight average molecular weight distribution of not higher than 1,000, and the nonionic polymeric substance has a weight average molecular weight of at least2,000. The liquid composition according to claim 8, wherein the peak exists in a weight average molecular weight distribution of not higher than 1,000, and the nonionic polymeric substance has a weight average molecular weight of not lower than 2,000, but not higher than 10,000.

10. The liquid composition according to claim 8 or claim 9, wherein the cationic oligomer and the nonionic polymer substance are contained in a range of from 0.05 to by weight in total. [N:\libaa]00978:rmn 103

11. The liquid composition according to any one of claims 8 to 10, wherein the cationic oligomer is selected from the group consisting of polyvinylamine, polyallylamine, polyvinylpyridine, polyethyleneimine and the hydrochlorides, acetates and, sulfates thereof.

12. The liquid composition according to any one of claims 8 to 10, wherein the cationic oligomer is selected from quaternary ammonium salts or polyoxyethylene derivatives having the following structure (C 2 H 4 0)mH I X' (C 2 H 4 0)nH wherein R and R' denote individually an alkyl or benzyl, m+n is an integer of 2 to 10, X- denotes Br-, I, CH 3 COO, or C 2 H 5 S0 3

13. The liquid composition according to any one of claims 8 to 12, further comprising a cationic surfactant.

14. The liquid composition according to any one of claims 8 to 13, wherein the mixing ratio of the cationic oligomer to the nonionic polymeric substance is within a range of from 10:1 to 1:10 by weight. The liquid composition according to any one of claims 8 to 14, wherein the pH of the liquid composition is from 3 to 12.

16. The liquid composition according to claim 15, wherein the pH is from 3 to 8.

17. An ink set comprising in combination the liquid composition according to any 20 one of claims 1 to 16, and at least one ink selected from the group consisting of yellow, magenta, cyan, black, red, blue and green inks, wherein the ink contains an anionic dye, or an anionic compound and a pigment.

18. The ink set according to claim 17, wherein the ink containing the anionic dye further contains an anionic compound.

19. The ink set according to claim 17 or claim 18, wherein the anionic compound is a polymeric substance having a weight average molecular weight of at least 1,000.

20. The ink set according to claim 17 or claim 18, wherein the anionic compound is a surfactant.

21. The ink set according to any one of claims 17 to 20, wherein the anionic dye S 30 is a water-soluble dye having an anionic group.

22. The ink set according to any one of claims 17 to 21, wherein the anionic compound is a dispersant for the pigment. S 23. The ink set according to any one of claims 17 to 22, wherein the pH of the ink is from 7 to

24. An ink set comprising in combination the liquid composition according to any one of claims 1 to 16, and four inks of yellow, magenta, cyan and black, wherein each of the inks contains an anionic dye or an anionic compound and a pigment. [N:\libaa]00978:rmn The ink set according to claim 24, wherein the ink containing the anionic dye further contains an anionic compound.

26. The ink set according to claim 24 or claim 25, wherein the anionic compound is a polymeric substance having a weight average molecular weight of at least 1,000.

27. The ink set according to any one of claims 24 to 26, wherein the anionic compound is a surfactant.

28. The ink set according to any one of claims 24 to 27, wherein the anionic dye is a water-soluble dye having an anionic group.

29. The ink set according to any one of claims 24 to 28, wherein the anionic compound is a dispersant for the pigment. The ink set according to any one of claims 24 to 29, wherein the pH of the ink is from 7 to

31. An ink set comprising in combination the liquid composition according to any one of claims 1 to 16, and three inks of yellow, magenta and cyan, wherein each of the inks contains an anionic dye or an anionic compound and a pigment.

32. The ink set according to claim 31, wherein'the ink containing the anionic dye further contains an anionic compound.

33. The ink set according to claim 31 or claim 32, wherein the anionic compound is a polymeric substance having a weight average molecular weight of at least 1,000.

34. The ink set according to any one of claims 31 to 33, wherein the anionic compound is a surfactant.

35. The ink set according to any one of claims 31 to 34, wherein the anionic dye is a water-soluble dye having an anionic group.

36. The ink set according to any one of claims 31 to 35, wherein the anionic compound is a dispersant for the pigment. ,37. The ink set according to any one of claims 31 to 36, wherein the pH of the ink is from 7 to

38. A recording unit for use in an ink-jet image forming process, comprising cartridges, one of which contains the liquid composition according to any one of claims 1 o 30 to 16, and another of which contains an ink containingan anionic dye or an anionic compound and a pigment; and a head for ejecting the liquid composition and the ink.

39. A cartridge capable of attaching to a recording unit for use in an ink-jet image forming process, the recording unit having a head, which cartridge contains the liquid o composition according to any one of claims 1 to 16.

40. A process for forming an image, which comprises the steps of: applying the liquid composition according to any one of claims 1 to 16 to at S least an image-forming region of a recording medium; and applying an ink comprising an anionic dye, or anionic compound and a pigment to the region on the recording medium, [N:\ibaa]00978:JJN ir ~q; 105 wherein the steps and are conducted so that the liquid composition and the ink coexist on the region.

41. The image-forming process according to claim 40, wherein at least one of the steps and is carried out by an ink-jet system.

42. The image-forming process according to claim 41, wherein the ink-jet system is an On-Demand type ink-jet system.

43. The image-forming process according to claim 42, wherein the ink-jet system is an ink-jet system in which thermal energy is applied to the ink.

44. The image-forming process according to claim 41, wherein the ink-jet system is an ink-jet system in which thermal energy is applied to the ink. The image-forming process according to claim 40, wherein the step is conducted prior to the step a.

46. The image-forming process according to claim 40, wherein the step is conducted subsequently to the step ao.. 15 47. The image-forming process according to claim 45 or 46, wherein the steps (A) and are conducted within 1 second.

48. An image-forming apparatus comprising the ink set according to any one of a claims 17 to 37, and an ink-jet means.

49. The image-forming apparatus according to claim 48, wherein the ink-jet means 20 is a means in which thermal energy is applied to the ink to eject the ink.

50. A recording unit for use in an ink-jet image forming process, comprising cartridges one of which contains the liquid composition according to any one of claims 1 to 16, and a head for ejecting the liquid composition and ink, said head being substantially S: as hereinbefore defined by reference to any one of Figures 1, 2 or 3. 25 51. A recording unit for use in an ink-jet image forming process, comprising cartridges, one of which contains the liquid composition according to any one of claims 1 to 16, substantially as hereinbefore described with reference to any one of Figures 4, 6 or 7.

52. A cartridge capable of attaching to a recording unit for use in an ink-jet system forming process, said cartridge containing the liquid composition according to any one of claims 1 to 16 and wherein said cartridge is substantially as hereinbefore described with reference to Figure

53. An image formed by the process of any one of claims 40 to 47. Dated 13 November, 1998 Canon Kabushiki Kaisha Patent Attorneys for the Applicant/Nominated Person A.SPRUSON FERGUSON [N:\libaa]00978:ssd