JP2002179965A - Aqueous fluorescent emission ink composition for jet printing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ink composition excellent in storage stability. SOLUTION: This aqueous fluorescent emission ink composition for jet printing contains a water-soluble resin and an aqueous dispersant containing a resin particle comprising a copolymer having an average particle diameter of not higher than 0.5 μm and obtained by emulsion polymerization of a monomer mixture of total not less than 80 wt.% of 30-80 pts.wt. polymerizable monomer A dyed with an invisible emissive substance and represented by formula (I) X is a hydrogen atom, etc., and Y is an acetoxy group, etc.}, and 20-70 pts.wt. polymerizable monomer B containing a cyano group, and not more than 20 wt.% of a polymerizable monomer C which is copolymerizable with them.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an aqueous fluorescent light-emitting ink composition for jet printing, and more particularly to an aqueous fluorescent light-emitting ink composition for jet printing that is colorless under visible light and emits light when irradiated with ultraviolet light.

[0002]

2. Description of the Related Art Conventionally, in the case of a jet printing ink using an invisible luminescent material, a solvent type is easily obtained due to the solubility of the luminescent material, but it is difficult to obtain an aqueous type. .

[0003]

SUMMARY OF THE INVENTION An object of the present invention is to provide an aqueous fluorescent luminescent ink composition for jet printing having excellent storage stability.

[0004]

According to the present invention, there is provided the following general formula dyed with an invisible luminescent material:

[0005]

Embedded image [Wherein X is a hydrogen atom or a methyl group, and Y is an acetoxy group, a phenyl group or a lower alkoxycarbonyl group represented by ROOC- (where R is an alkyl group having 1 to 4 carbon atoms)]. ] The polymerizable monomer A represented by
A monomer mixture of 30 to 80 parts by weight of one or more of the following and 20 to 70 parts by weight of a polymerizable monomer B containing a cyano group, or one or two or more of the polymerizable monomers A A monomer mixture of a total of 80% by weight or more of 30 to 80 parts by weight of the seeds and 20 to 70 parts by weight of the polymerizable monomer B, and 20% by weight or less of the polymerizable monomer C copolymerizable therewith. An aqueous fluorescent light-emitting ink composition for jet printing, comprising an aqueous dispersion containing resin particles comprising a copolymer having an average particle diameter of 0.5 μm or less obtained by emulsion polymerization and a water-soluble resin. .

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail.

The polymerizable monomer A as a component of the aqueous dispersion containing the resin particles dyed with the invisible light-emitting substance used in the present invention is represented by the above general formula. Specifically, methacrylates such as vinyl acetate, styrene, methyl methacrylate, ethyl methacrylate, butyl methacrylate, methyl acrylate,
Acrylic esters such as ethyl acrylate and butyl acrylate are exemplified. Examples of the polymerizable monomer B include acrylonitrile and methacrylonitrile.

[0008] In the present invention, depending on the blending ratio of the polymerizable monomers A and B, the emission luminance, light fastness and polymerization stability due to ultraviolet irradiation change due to the degree of dyeing of the invisible light emitting substance.

When the amount of the monomer B exceeds the above range, the polymerization stability becomes extremely poor, and an undesired phenomenon of gelation and coarse particles occurs. Also,
On the other hand, when it is less than the above range, the polymerization stability is not hindered, but there are problems in light emission luminance and light fastness. That is, the monomer B having a cyano group has a very strong electron-withdrawing property as a property of the cyano group, and has an effect of suppressing the formation of peroxide that adversely affects light fastness. It is considered to have a role of improving light fastness because of its excellent neutralization property. Further, the monomer having a cyano group has a function as a polar group that uniformly disperses and dyes the luminescent substance without associating the luminescent substance, and also has an effect of improving solvent resistance and softening point.

Examples of the polymerizable monomer C include acrylic acid, methacrylic acid, acrylamide, glycidyl methacrylate, 2-hydroxy-3-chloropropyl methacrylate, sodium methacrylsulfonate, sodium vinylbenzenesulfonate, hydroxyethyl methacrylate, and acid phosphonate. Examples include monomers containing a carboxyl group, a hydroxyl group, a sulfonic acid group, and salts and amide groups thereof, such as oxyethyl methacrylate and acid phosphooxy polyoxypropylene glycol monomethacrylate.
The purpose of using these monomers is to improve the dyeing properties of the luminescent material. In addition, a monomer such as divinylbenzene, ethylene glycol dimethacrylate, or trimethylolpropane trimethacrylate may be used as a monomer for the purpose of improving the solvent resistance and heat resistance by crosslinking the copolymer to make it chemically stable. Can be used as body C.

The mixing ratio of each polymerizable monomer is as described above, but more preferably 50 to 70 parts by weight of one or more of monomer A and a monomer containing a cyano group B is 30 to 50 parts by weight, or a total of 85% by weight or more of the monomer A and the monomer B in the above ratio, and 15% by weight or less of a monomer C copolymerizable therewith.

The aqueous dispersion of the present invention is obtained by aqueous emulsion polymerization, and the particle size of the resin particles comprising the copolymer contained in the aqueous dispersion is 0.5 μm or less.
If the particle size of the resin particles exceeds 0.5 μm, clogging of the nozzle is likely to occur, and the resin particles are likely to settle in the aqueous ink and lack storage stability.

The emulsion polymerization method of the present invention is carried out by appropriately selecting the type and amount of the surfactant according to the purpose, and the polymerization temperature is preferably from 50 to 90 ° C.

The surfactants preferably used in the present invention include alkyl benzene sulfonate, alkyl phenol sulfonate, sulfonate having alkyl diphenyl ring, formalin condensate of alkyl allyl sulfonic acid, and alkyl allyl sulfonate Ketone compounds, sulfosuccinate salts, anionic surfactants such as polyoxyethylene alkylsulfonate salts and fatty acids and esters such as glycerin, glycol, pentaerythritol, sorbitan, or mannitan,
Or nonionic surfactants such as condensates of polyethylene oxide with higher fatty acids, higher alcohols, higher alkylamines, or alkylphenol phosphoric acids, etc., when only anionic surfactants are used or when nonionic surfactants are used Etc., preferably,
Nonionic polymerizable surfactants, specifically, "Adekaria Soap NE-10" and "NEDO" manufactured by Asahi Denka Kogyo Co., Ltd.
-20 "," NE-30 "," NE-40 "," SE-10N "," Latemul S-180 "manufactured by Kao Corporation,
"S-180A", a higher alcohol ether type nonionic surfactant "Emulgen LS-106, 110, 1"
14 "," MS-110 "," S-120A "," Eleminol JS-2 "manufactured by Sanyo Chemical Industries, and the like, and one or more of them are used in combination.

Examples of the polymerization initiator include ammonium persulfate, potassium persulfate, and hydrogen peroxide. If necessary, a reducing agent may be used in combination.

The copolymer used in the aqueous dispersion of the present invention is:
Preferably, the polymerizable monomer, a polymerizable surfactant,
Ammonium persulfate, potassium persulfate, hydrogen peroxide or the like is used as a polymerization initiator or, if necessary, a reducing agent in combination with the polymerization initiator, and is synthesized by a usual emulsion polymerization method.

As the invisible light-emitting substance used in the aqueous dispersion of the present invention, europium may be added to 4,4,4-trifluoro-1- (2-thienyl)-as a red light-emitting substance.
Complexes in which one or more ligands such as 1,3-butanedione and tri-n-octylphosphine oxide are coordinated are exemplified. 3- (2-quinolylmethylene) isoindoline-1-one as a green light-emitting substance, C.I. I.
Basic Yellow 40, C.I. I. Solvent Yellow 160 and the like. As a blue light emitting substance, C.I. I. Fluorescing brightening agent 52, C.I.
I. Fluorescent Brightening Agent 13
5, C.I. I. Fluorescent brightening agents such as Fluorescent Brightening Agent 184.

Dyeing with these luminescent substances can be carried out either at the time of emulsion polymerization or after the polymerization. Regarding the conditions, under atmospheric pressure or under pressure, 40 to 110
C. for 1 to 5 hours, and the amount of the luminescent substance used is preferably 0.01 to 15.0 parts by weight, and more preferably 0.01 to 15.0 parts by weight based on 100 parts by weight of the resin particles (emulsion polymer solid content).
5 to 8.0 parts by weight is more preferred.

The dyeing of the luminescent substance can be carried out by a conventional method, but is preferably carried out using a surfactant. When the emulsion polymer is anionic or nonionic, the luminescent substance is dyed. Regardless of the type, the surfactant is preferably anionic or nonionic. The polarities of the emulsion polymer, the luminescent substance and the surfactant are appropriately selected according to the purpose.

The water-soluble resin used in the present invention stably disperses an aqueous dispersion containing resin particles dyed with an invisible light-emitting substance in ink, improves the storage stability of the ink, and achieves uniform marking. It is a component that is blended so that it can be formed.

As the water-soluble resin, those generally used for inks and paints can be used without any particular limitation. Specifically, polyacrylic acid, polyacrylate, styrene-maleic acid copolymer , Styrene sulfonic acid-maleic acid copolymer, polyester, hydroxyethyl cellulose, polyvinyl alcohol, maltosyl cyclodextrin, polyethylene glycol and the like.

The solvent used in the present invention is water, preferably distilled water or ion-exchanged water, and if necessary, methyl alcohol, ethyl alcohol, isopropyl alcohol, dioxane, acetone, methyl ethyl ketone, carbitol, dimethyl. It is also possible to partially use a water-miscible organic solvent such as sulfoxide.

The aqueous fluorescent light-emitting ink composition for jet printing of the present invention contains the above-described components as essential components. The mixing ratio of these components is as follows. % By weight, preferably 5-2
0% by weight, 0.1-20% by weight of water-soluble resin, preferably 0.5-10% by weight,
Suitably, it is 50% by weight, preferably 5 to 30% by weight.

The aqueous fluorescent light-emitting ink for jet printing according to the present invention further comprises a conductivity adjusting agent such as lithium nitrate, lithium nitrite, ammonium sulfite, ammonium formate, ammonium acetate, lithium halide, sodium thiocyanate, and amine. Dispersants such as modified silicone dispersants,
Additives such as preservatives can be included in amounts of 0.1 to 5% by weight.

Further, the aqueous fluorescent light emitting ink for jet printing of the present invention needs to have characteristics suitable for printing by an ink jet printer. Accordingly, the aqueous fluorescent ink for jet printing of the present invention has a viscosity of about 1 to 100 m.
Pa · sec (20 ° C), resistivity about 50-30000
Ω · cm, specific gravity about 0.8-1.2, surface tension about 20
It is desirable to be in the range of 60 dynes / cm.

The aqueous fluorescent light-emitting ink for jet printing of the present invention may be prepared by mixing and stirring all the above-mentioned components at once or mixing a fluorescent dye, water-dispersible acrylic resin fine particles, a water-soluble resin and a part of a solvent in advance. The fluorescent dye is adsorbed on the fine particles by stirring, and the remaining components are mixed and stirred, and then filtered and purified through a filter having a pore size of about 1/10 or less of the nozzle diameter of the ink jet printer to be used.

In the present invention, conventionally known various printers can be used as the ink jet printer, and examples thereof include a charge control system, an ink-on-demand system, and a system in which ink is ejected by a thermal head. Can be

In the aqueous fluorescent light-emitting ink composition for jet printing of the present invention, a mark is formed by discharging the above-mentioned aqueous fluorescent light-emitting ink on the surface of a printing substrate by an ink jet printer and printing in a desired form. By irradiating excitation energy having a wavelength of 250 to 380 nm on the mark after the marking, the mark emits fluorescence, and the mark can be read visually or by a device such as a photodetector.

[0029]

The present invention will be described below with reference to examples.

Example 1 A 2 liter flask was equipped with a cooling tube, a thermometer, a 500 ml separating funnel for charging monomers, and a stirrer, and was set in a hot water layer.

Next, 600 g of water, 10 g of Neoperex No. 6 (manufactured by Kao Corporation; sodium dodecylbenzenesulfonate) and 5.5 g of Emulgen LS-114 (manufactured by Kao Corporation; higher alcohol ether) were added to the flask and stirred. The internal temperature was raised to 80 ° C. while heating.

On the other hand, after mixing 252 g of styrene, 108 g of acrylonitrile, and 40 g of acrylic acid, 3.5 g of potassium persulfate was charged into a flask maintained at 80 ° C., and the mixed monomers were stirred from a separating funnel for 3 hours. The mixture was added dropwise, and the polymerization was completed over 1 hour.

To the above mixture, 24 g of Demol SC-30 (manufactured by Kao Corporation; sodium salt of a special aromatic sulfonic acid formalin condensate) and FP Yellow M (manufactured by Mitsui Chemicals; 3-
(2-quinolylmethylene) isoindoline-1-one)
4 g was added at room temperature under stirring and mixed uniformly. Then, the temperature was gradually raised and dyed for 1 hour at 80 ° C.
A fine yellow aqueous dispersion of fine particles was obtained at μm.

After uniformly mixing 1.8 g of the fine particle aqueous dispersion, 24.0 g of maltosyl cyclodextrin, 39.2 g of water and 35.0 g of ethyl alcohol, the mixture was filtered and purified through a membrane filter having a pore size of 1.0 μm. An ink composition for jet printing was prepared.

The ink composition for jet printing was dot-printed on art paper by a charge control type ink jet printer.

The coated paper looks the same as before coating under visible light, but when irradiated with ultraviolet light (black light), it shows a clear yellow-green luminescent color.

Example 2 18 g of Neocol SW (manufactured by Daiichi Kogyo Seiyaku; sodium dialkyl sulfosuccinate) and Ubitex ERN Conc (manufactured by Ciba Geigy) were added to the aqueous dispersion obtained in the same manner as in Example 1. CI Fluorescent Brightening Agent 135) 8
g was added at room temperature with stirring and mixed well. Then, the mixture was heated to 80 ° C., dyed for 1 hour and dyed with a particle diameter of 0.1 g.
A milky white fine particle aqueous dispersion of 1 μm was obtained.

Using the above aqueous dispersion, an ink composition for jet printing was prepared in the same manner as in Example 1 and printed on art paper.

The coated paper looked the same as before coating under visible light, but when irradiated with ultraviolet light (black light), it emitted a clear blue luminescent color.

Example 3 28 g of Demol NL (manufactured by Kao Corporation; sodium salt of β-naphthalenesulfonic acid formalin condensate) was added to the aqueous dispersion obtained in the same manner as in Example 1, and europium: 4,4,4- Trifluoro-1- (2-thienyl) -1,3-butanedione complex (Sinloich)
After adding 5 g while stirring at room temperature and mixing well,
The mixture was heated to 80 ° C. and dyed for 1 hour to obtain a milky white fine particle aqueous dispersion having a particle diameter of 0.1 μm.

Using the above aqueous dispersion, an ink composition for jet printing was prepared in the same manner as in Example 1 and printed on art paper.

The coated paper looked the same as before coating under visible light, but when irradiated with ultraviolet light (black light), it emitted a bright red luminescent color.

Comparative Example 1 Styrene 32 was used as a monomer.
0 g, acrylonitrile 40 g, and acrylic acid 40 g were used, and the others were polymerized in the same manner as in Example 1;
4 g of yellow M was dyed to obtain a pale yellow aqueous dispersion of fine particles having a particle diameter of 0.1 μm. The composition for jet printing is
Prepared in the same manner as in Example 1.

The following comparative tests were conducted to show the usefulness and superiority of the present invention.

<Ultraviolet light resistance test> Using an ultraviolet light (black light main wavelength: 365 nm), 3200 μW / c
With a strength of m ² , the coated paper of Examples 1 to 3 and Comparative Example 1
Irradiated for 0 hours. The coated paper before and after the irradiation test was irradiated with an ultraviolet light to visually determine the emission luminance. Table 1 shows the results.

Judgment Criteria 5: No Luminance Brightness Decay 4: Slight Decay 3: Significant Decay 2: Slight Decay 1: Slight Decay

<Storage Stability Test> The inks of Examples 1 to 3 and Comparative Example 1 were placed in a glass container and stored in a thermostat kept at 60 ° C. for 30 days. The ink after the storage test was dot-printed on art paper by a charge control type ink jet printer, irradiated with an ink coated paper before the test and an ultraviolet light, and the emission luminance was visually determined. Table 1 shows the results.

The criterion is the same as in the above-mentioned ultraviolet light resistance test.

[0049]

[Table 1] As is clear from the above table, the ink for jet printing obtained as a result of the practice of the present invention is excellent in various physical properties.

[0050]

The aqueous fluorescent light-emitting ink composition for jet printing of the present invention has a small emission luminance decay due to ultraviolet irradiation and has excellent storage stability.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Tsuneo Shirota 1-18-3 Nakazato, Minato-ku, Yokohama-shi, Kanagawa Prefecture No. 31 102 F-term (reference) 2C056 EA13 FC01 2H086 BA56 BA59 BA60 BA62 4J039 AD03 BC59 BE02 BE08 GA24

Claims (2)

[Claims] 1. The following general formula dyed with an invisible luminescent material: [Wherein X is a hydrogen atom or a methyl group, and Y is an acetoxy group, a phenyl group or a lower alkoxycarbonyl group represented by ROOC- (where R is an alkyl group having 1 to 4 carbon atoms)]. ] The polymerizable monomer A represented by
A monomer mixture of 30 to 80 parts by weight of one or more of the following and 20 to 70 parts by weight of a polymerizable monomer B containing a cyano group, or one or two or more of the polymerizable monomers A A monomer mixture of a total of 80% by weight or more of 30 to 80 parts by weight of the seeds and 20 to 70 parts by weight of the polymerizable monomer B, and 20% by weight or less of the polymerizable monomer C copolymerizable therewith. An aqueous fluorescent light-emitting ink composition for jet printing, comprising: an aqueous dispersion containing resin particles comprising a copolymer having an average particle diameter of 0.5 μm or less obtained by emulsion polymerization; and a water-soluble resin. 2. The resin particles according to claim 1, wherein said invisible light-emitting substance is a europium complex as a red light-emitting substance, 3- (2-quinolylmethylene) isoindoline-1-one as a green light-emitting substance, and a blue light-emitting substance. The fluorescent whitening agent is used alone or in combination with the resin particles in an amount of 0.05 to
The aqueous fluorescent luminescent ink composition for jet printing according to claim 1, which is dyed at 8.0% by weight.