JPH07278479A - Fine polymer particle for ink-jet recording ink - Google Patents

Abstract

PURPOSE:To obtain polymer particles useful for obtaining an ink-jet recording ink excellent in stability to ejection from a nozzle and in drying property and printed-image quality regarding freedom from blurring, image contour sharpness, clearness, durability, etc. CONSTITUTION:The particles are obtained by polymerizing a monomer mixture comprising at least 5wt.% crosslinking monomer having two or more groups having a polymerizable double bond per molecule and at least 2wt.% hydrophilic monomer having a hydrophilic group, e.g. a carboxyl, hydroxyl, sulfonic acid, or amide group. The particles have an average particle diameter of 0.010.1mum.

Description

Detailed Description of the Invention

[0001]

INDUSTRIAL APPLICABILITY The present invention is excellent in drying property when ink is ejected as droplets ejected from an ejection orifice of a recording head to cause bleeding, sharpness of contour, sharpness and durability. The present invention relates to polymer particles which are excellent in printing quality such as, and are excellent in nozzle ejection stability and which can provide an inkjet recording ink suitable for pattern printing on cloth and the like.

[0002]

2. Description of the Related Art Conventionally, those that have a high drying speed after printing are
There is a problem that nozzle ejection stability is deteriorated due to clogging that accompanies drying and solidification of ink, and conversely, those having good ejection stability have poor drying properties. To achieve both of these, JP-A-55-1
No. 6042, JP-A-55-29546, etc.
It has been proposed to use a dye, a specific high-boiling point water-soluble solvent (wetting agent) and water as main components in order to improve nozzle ejection stability, and various surfactants for improving quick drying property.
However, the ink penetrates too much into the paper, causing bleeding,
There were new problems such as sharpness of contour, sharpness, and durability, which deteriorated the printing quality, which was not satisfactory. On the other hand, in JP-A-3-79678, 50-30
A method of adding a 0 angstrom ultrafine particle emulsion is disclosed. Also, JP-A-54-5850
4, JP-A-60-38481, JP-A-55-139.
No. 471, JP-A-3-250069, a hydrophobic dye,
An ink jet recording ink comprising a polymer emulsion colored with a basic dye and a disperse dye is disclosed. However, in these methods, although the blurring and the sharpness of the contour are good, there is a problem that the nozzle is hard to be clogged because the film forming property of the fine particles is too good, the nozzle ejection stability is deteriorated, and the printing is blurred. On the other hand, when an inorganic pigment or an organic pigment such as iron oxide, titanium oxide or carbon black is used as a colorant, a large amount of dispersant is required, and a natural or synthetic water-soluble polymer is usually used. However, when these dispersants are used, the viscosity is increased, the droplets are less likely to fly, and the ejection stability is deteriorated. In particular, it is not possible to faithfully print the design with a cloth or the like.

[0003]

SUMMARY OF THE INVENTION The present invention has been made against the background of the above-mentioned conventional technical problems, and is excellent in drying property and excellent in print quality such as bleeding, sharpness of contour, sharpness and durability. Another object of the present invention is to provide polymer fine particles for inkjet recording ink, which are excellent in nozzle ejection stability and which are suitable for pattern printing on cloth and the like.

[0004]

According to the present invention, 5% by weight or more of a crosslinkable monomer having two or more groups having a polymerizable double bond in one molecule (hereinafter simply referred to as "crosslinkable monomer"). , And a hydrophilic monomer having a hydrophilic group (hereinafter,
An average particle diameter of 0.01 to 0. 5, which is characterized by being obtained by polymerizing a polymerizable monomer containing 2% by weight or more of "a hydrophilic monomer having a functional group").
The present invention provides polymer fine particles for an inkjet recording ink having a size of 1 μm. Hereinafter, the present invention will be described in detail.

As the crosslinkable monomer, a non-conjugated polyvinyl compound typified by divinylbenzene or a polyvalent acrylate compound typified by trimethylenepropanetrimethacrylate, which has two or more copolymerizable double bonds described below, is used. Compounds may be mentioned, and these may be used alone or in combination of two or more. Specific examples of the crosslinkable monomer used in the present invention include polyethylene glycol diacrylate, 1,3-butylene glycol diacrylate, 1,6-butylene glycol diacrylate, 1,
6-hexanelene glycol diacrylate, neopentyl glycol diacrylate, polypropylene diacrylate, 2,2'-bis (4-acryloxyproproxyphenyl) propane, 2,2'-bis (4-acryloxydiethoxyphenyl) Diacrylate compounds such as propane, triacrylate compounds such as trimethylolpropane triacrylate, trimethylolethane triacrylate, tetramethylolmethane triacrylate, etc. Acrylate compound, ethylene glycol dimethacrylate,
Diethylene glycol dimethacrylate, triethylene glycol dimethacrylate, polyethylene glycol methacrylate, 1,3-butylene glycol dimethacrylate, 1,4-butylene glycol dimethacrylate,
Methacrylate compounds such as 1,6-hexane glycol dimethacrylate, neopentyl glycol dimethacrylate, dipropylene glycol dimethacrylate, polypropylene glycol dimethacrylate, 2,2-bis (4-methacryloxydiethoxyphenyl) propane, trimethylolpropane tri Examples thereof include trimethacrylate compounds such as methacrylate and trimethylolethanetrimethacrylate, methylenebisacrylamide, and divinylbenzene. Of the above, divinylbenzene, ethylene glycol dimethacrylate, or trimethylolpropane trimethacrylate is preferably used, and divinylbenzene is particularly preferable. The amount of the crosslinkable monomer used is 5% by weight or more of the polymerizable monomer, preferably 7 to 95% by weight, more preferably 10 to 90%.
% By weight. If the content of the crosslinkable monomer is less than 5% by weight of the polymerizable monomer, the dried and solidified ink becomes more clogged and the nozzle ejection stability becomes poor.

As the hydrophilic monomer having a hydrophilic group such as a carboxyl group, a hydroxyl group, a sulfonic acid group and an amide group used in the present invention, a mono- or dicarboxylic acid such as acrylic acid, methacrylic acid, maleic acid or itaconic acid can be used. Monomers, 2-acryloyloxyethyl-2-hydroxyethyl phthalic acid, 2-hydroxy-3-phenoxypropyl acrylate, 2-hydroxyethyl methacrylate, N-methylol acrylamide and other hydroxyl group-containing monomers, sodium styrene sulfonate, sulfonated isoprene, etc. Examples thereof include acid group-containing monomers and amide compound monomers such as acrylamide and methacrylamide. The hydrophilic monomer having a functional group accounts for 2 to 50% by weight, particularly 4 to 30% by weight of the polymerizable monomer.
It is preferable that the content of the polymer particles for the ink jet recording ink is contained in an amount of 1 wt% in order to improve the ink fixing property and the printing durability.

Further, in the present invention, other than the crosslinkable monomer and the hydrophilic monomer having a functional group, other copolymerizable monomers can be mentioned, and these are used alone or in combination of two or more. Examples of the copolymerizable monomer include aromatic monovinyl compounds such as styrene, ethylvinylbenzene, α-methylstyrene, fluorostyrene and vinylpyrine, butyl acrylate, 2-ethylhexyl acrylate, β-methacryloyloxyethylhydrogenphthalate, N, N. Acrylic ester monomers such as ′ -dimethylaminoethyl acrylate, 2-ethylhexyl methacrylate, methoxydiethylene glycol methacrylate, methoxypolyethylene glycol methacrylate, methyl methacrylate,
Ethyl methacrylate, butyl methacrylate, N,
Examples thereof include methacrylic acid ester monomers such as N′-dimethylaminoethyl methacrylate and glycidyl methacrylate, vinyl cyanide compounds such as acrylonitrile and methacrylonitrile, silicon-modified monomers and macromonomers. In addition, butadiene,
Conjugated double bond compounds such as isoprene and vinyl ester compounds such as vinyl acetate, 4-methyl-1-pentene,
Other α-olefin compounds may be mentioned. Among the copolymerizable monomers, styrene, methyl methacrylate, acrylonitrile and the like are preferable. The amount of the copolymerizable monomer used is usually 1 to 93% by weight, preferably 5 to 80% by weight of the polymerizable monomer.

Next, a preferred method for producing the polymer fine particles for ink jet recording ink of the present invention will be described. Examples of the method of adding the polymerizable monomer in the emulsion polymerization for obtaining the above-mentioned polymer fine particles include a method of adding the whole amount at once and a method of adding a part or the whole amount continuously or intermittently. A seed emulsion polymerization method can also be used.
The polymerization initiator used in the above emulsion polymerization is not particularly limited as long as it is used in a usual emulsion polymerization, potassium persulfate, sodium persulfate, persulfate initiators such as ammonium persulfate, azo. The system initiator and hydrogen peroxide, organic peroxide and the like may be used alone or in combination with various reducing agents such as ascorbic acid.

Usual surfactants can be used as the surfactant used in the above emulsion polymerization.
Dodecylbenzene sulfonate, dodecyl sulfate, lauryl sulfate, dialkyl sulfosuccinate, polyoxyethylene alkyl phenyl ether sulfate, polyoxyethyne alkenyl propenyl phenyl ether sulfate,
Anionic surfactants such as a formalin condensate of naphthalene sulfonic acid can be exemplified. Here, examples of the salt include sodium and ammonium. Furthermore, it is also possible to use nonionic surfactants such as polyoxyethylene nonylphenyl ether, polyethylene glycol monostearate, polyoxyethylene alkylpropenyl phenyl ether, sorbitan monostearate.

Further, it is possible to use a generally known reactive emulsifier such as sodium naphthalenesulfonate alone or in combination with the above-mentioned surfactant. These may be used alone or in combination. As a method for synthesizing the polymer ultrafine particles of the present invention, it is also possible to polymerize using polystyrene ultrafine particles as a seed. The average particle diameter of the polymer fine particles for inkjet recording ink of the present invention is 0.01 to 0.1 μm, preferably 0.02 to 0.09 μm, and more preferably 0.03 to 0.08 μm. The average particle diameter here is measured by the following method. The average particle diameter of the polymer fine particles for ink jet recording ink is measured by directly measuring 100 particles by a transmission electron micrograph (if the particles are not spherical, the long diameter and the short diameter are measured and the average value thereof is measured). Is calculated.) Is performed.

The polymer fine particles for ink jet recording ink of the present invention can be basically mixed with a dye (or pigment) and a medium to prepare an ink jet recording ink. Examples of dyes that can be used in the present invention include acid dyes, basic dyes, direct dyes, disperse dyes, and reactive dyes. Specifically, as the black dye, Direct Black # 19 (C.I.
5), Direct Black # 154, Hood Black #
2 (C.I. 27755), Solvent Black # 3,
Solvend Block # 22, Solvent Black # 2
3, acid yellow # 23 as a yellow dye such as Disperse Black # 1 (C.I. 11365)
(CI.19140), Solvent Yellow # 19,
Solvent Yellow # 21, Solvent Yellow # 6
1, Solvent Yellow # 80, Disperse Yellow #
7 (CI.26090) and the like, as a magenta dye, Acid Red # 87 (CI.45380), Acid Red # 106 (CI.45100) and the like, Solvent Red # 8, Solvent Red # 49, Solvent. Red # 81, Solvent Red # 82, Solvent Red # 83, Solvent Red # 84, Solvent Red # SO100, Solvent Red # 109, Solvent Red # 121, Disperse Red 1 (C.I.111).
10) Acid Blue # 9 (C.I.I.) as a cyan dye such as Disperse Red 4 (C.I. 60755).
42090), Direct Blue # 86 (C.I. 74)
180), Solvent Blue # 11, Solvent Blue # 12, Solvent Blue # 25, Solvent Blue #
36, Solvent Blue # 55, Solvent Blue # 7
3, Disperse Blue # 1 (CI.64500), Disperse Blue # 3 (CI. 61505), Disperse Blue # 5 (CI. 62035), and the like.

As the pigment, those in which ordinary organic pigments or inorganic pigments are dispersed in fine particles are used, and those in which the particle diameter of the pigment is 0.1 μm or less are preferable. If the amount of the dye or pigment added is less than 0.5% by weight of the ink jet recording ink, sufficient color tone and density cannot be obtained, and if it exceeds 10% by weight, clogging is likely to occur. % Is preferred. Further, as the medium, water or other aqueous medium, for example, ethylene glycol, prolene glycol butylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol 200, 400, 600, 150.
0, glycerin, n-methylolprolidone, ethylene glycol monobutyl ether, ethylene glycol monoethyl ether, ethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol diethyl ether and the like.
These aqueous media are usually added in an amount of 10 to 99% by weight of the inkjet recording ink. The polymer fine particles for an inkjet recording ink of the present invention have a total solid content of the inkjet recording ink of 0.1 to 90% by weight, preferably 1 to
70% by weight is added. In addition to the above, water-soluble polymers, polymer emulsions, surfactants, pH adjustors, antiseptic and antifungal agents, antirust agents, chelating agents, ultraviolet absorbers, infrared absorbers, etc. should be added to the inkjet recording ink. You can

The ink jet recording ink containing the fine polymer particles of the present invention is suitable for printing on cloth such as woven cloth and non-woven cloth, and the material of cloth is natural materials such as wool, cotton, silk and hemp. A wide variety of chemical fibers such as viscose, rayon, polyester, polyacrylonitrile, nylon 6 and nylon 66 can be used. Further, a waterproofing agent, a water repellent agent or the like may be applied to these cloths.

[0015]

EXAMPLES Examples of the present invention will be described below, but the present invention is not limited thereto. In the following description, "part" means "part by weight" and "%" means "% by weight". Example 1 Divinylbenzene (manufactured by Sankyo Kasei, purity 55%, residual 4
0% is ethyl vinyl benzene, the remaining 5% is diethylbenzene) 18 parts, styrene 77 parts, acrylic acid 10 parts,
15 parts of sodium dodecylbenzenesulfonate, 900 parts of ion-exchanged water and 1 part of sodium persulfate were charged into a reaction vessel, and polymerization was carried out at 80 ° C. for 1 hour under stirring. The average particle size of the obtained polymer fine particles a for inkjet recording ink (hereinafter referred to as particle a) was measured and found to be 0.03 μm.
It was m. An ink jet recording ink having the following composition was prepared using the obtained polymer fine particles a. Disperse black # 1 3% Glycerin 4% Polymer fine particles a 10% Water 83% The above components were thoroughly mixed and stirred with a tabletop sand mill (Kansai Paint Co., Ltd.), and filtered with a pore size 5 μm polyester filter (Nippon Pall Ltd.). Then, an inkjet recording ink was prepared.

Using the ink jet recording ink thus obtained, printing was carried out using a commercially available ink jet printer, and the following evaluations were carried out. The results are shown in Table 1. As the evaluation paper, PPC paper having a size of 17 seconds and stock form paper having a size of 16 seconds were used. (1) Drying speed After printing for 5 seconds, the printed portion was rubbed with a finger and the presence or absence of deviation of the ink was observed. ◯: No misalignment was found between the two types of paper. X: A slight deviation is recognized on either of the two types of paper. (2) Sharpness After printing, bleeding of the screen and uneven density were visually observed. ◯: Both types of paper bleed at all and no density unevenness is observed. X: Bleeding and density unevenness are recognized even on either of the two types of paper. (3) Jetting stability After the ink was filled in the printer and left for 3 months, reprinting was performed to evaluate whether or not printing could be performed smoothly. ◯: Printing was successful. X: Clogging was observed in the nozzle and printing was impossible.

Examples 2 to 8 and Comparative Examples 1 to 4 Emulsion polymerization was carried out in the same manner as in Example 1 except that the amounts of various monomers and emulsifiers were changed as shown in Table 1 to produce various polymer fine particles. did. An inkjet recording ink was prepared in the same manner as in Example 1 using the obtained various polymer fine particles, and the drying rate, sharpness, and jetting stability were evaluated in the same manner as in Example 1. The results are shown in Table 1. Comparative Example 5 An inkjet recording ink was prepared in the same manner as in Example 1 except that no polymer fine particles were used.
The sharpness and jetting stability were evaluated in the same manner as in Example 1.
The results are shown in Table 1.

[0018]

[Table 1]

Example 9 An ink jet recording ink was evaluated in the same manner as in Example 1 except that the paper used for evaluation in Example 1 was replaced with a woven polyester fiber cloth, and the drying speed, sharpness and jetting were evaluated. All of the stability were good.

[0020]

INDUSTRIAL APPLICABILITY The ink jet recording ink using the polymer fine particles for ink jet recording ink of the present invention is excellent in quick-drying property, is excellent in print quality such as bleeding, sharpness of contour, sharpness and durability, and further has a nozzle Excellent discharge stability.

Claims (1)

[Claims] 1. A polymerizable composition containing 5% by weight or more of a crosslinkable monomer having two or more groups having a polymerizable double bond in one molecule and 2% by weight or more of a hydrophilic monomer having a hydrophilic group. Polymer fine particles for inkjet recording ink having an average particle diameter of 0.01 to 0.1 μm, which are obtained by polymerizing a monomer.