JP2009227825A - Inkjet printing ink, and manufacturing method of electrode for flat panel display using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide inkjet printing ink which can be manufactured at a low cost and is excellent in dispersion stability. <P>SOLUTION: The inkjet printing ink comprises: (a) an electrically conducting powder; (b) a compound having at least one polymerizable unsaturated bond; (c) a compound having at least two groups represented by the formula (1) [wherein * represents a free valency]; and (d) a photopolymerization initiator. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an ink for inkjet printing and a method for producing a flat panel display member. More specifically, the present invention relates to an ink for inkjet printing suitable for forming an electrode constituting a flat panel display, and a method for producing an electrode for flat panel display using the same.

  Flat panel displays (hereinafter also referred to as “FPD”) such as field emission displays (hereinafter also referred to as “FED”) and plasma display panels (hereinafter also referred to as “PDP”) are manufactured while being large-sized panels. The flat panel display technology has attracted attention because of its easy process, wide viewing angle, high light emission type display quality, and the like. In particular, the color PDP is expected to become the mainstream in the future as a display device for a wall-mounted TV of 30 inches or more.

The FED is a display that displays information by causing a phosphor to emit light by emitting electrons from a cathode into a vacuum by applying an electric field and irradiating the electrons on the anode.
The color PDP can display color by irradiating phosphors with ultraviolet rays generated by gas discharge. In general, in a color PDP, a phosphor portion for red light emission, a phosphor portion for green light emission, and a phosphor portion for blue light emission are formed on a substrate, so that the light emitting display cells of each color are entirely formed. Are uniformly mixed. Specifically, a partition made of an insulating material called a barrier rib is provided on the surface of a substrate made of glass or the like, and a large number of display cells are partitioned by the partition, and the inside of the display cell has a plasma action. It becomes space. Then, a phosphor part is provided in the plasma working space, and an electrode for causing plasma to act on the phosphor part is provided, whereby a plasma display panel having each display cell as a display unit is configured. The said electrode is normally comprised by the lamination pattern which has a white conductive layer containing silver etc., and the dark color layer (black layer) which has a role of an antireflection layer (light-shielding layer) in the lower layer of this white conductive layer. In order to improve the contrast of the normal PDP, a black matrix or a color filter is provided between the electrode patterns.

As a method for producing a panel material in such an FPD, (1) an ion sputtering method, an electron beam evaporation method, or the like, and (2) an inorganic powder-containing resin layer pattern formed by a photolithography method, a screen printing method, or the like. A method is known in which the organic material is removed by baking the organic material. Among them, a photolithography method using a photosensitive paste or a photosensitive dry film is preferably used because of high manufacturing efficiency and in principle excellent pattern accuracy.
Japanese Patent Laid-Open No. 11-162339 JP 2001-84833 A JP 2002-245932 A JP 2003-51250 A JP 2000-268716 A JP 2007-112884 A

However, the photolithography method is excellent in pattern accuracy, but requires processes such as exposure, development, and washing, and the processing of the developer is also expensive. In addition, most of the material is washed away by development, and it is difficult to collect expensive inorganic powder in the developer, which increases the cost. Moreover, a photomask used for exposure is necessary, and time and cost are required when changing the pattern design.

  The screen printing method is a lean process because the electrode pattern is printed directly on the substrate, but only a pattern with a line width of up to about 100 μm can be stably formed. There is a problem that it can not cope.

  In order to solve this problem, a method of forming a fine pattern having a line width of 100 μm or less using an ink jet method has been developed. However, in this method, the dispersibility of the pigment in the ink is poor and the filterability at the time of ink preparation is poor, and the sedimentation stability and ejection stability of the ink after preparation are poor, and a good pattern is continued. There was a problem that it was difficult to form. In order to solve these dispersibility problems, the particle size of the pigment particles used is generally reduced to 50 nm or less. However, such particles are expensive and have the cost merit of de-photolithography. Since it is lost, it is not preferable.

The present invention has been made based on the above situation.
A first object of the present invention is to provide an ink for inkjet printing that is low in cost and excellent in dispersion stability.

  A second object of the present invention is to provide an FPD electrode manufacturing method capable of forming an electrode, which is an FPD panel member, with high accuracy and at low cost.

As a result of intensive studies to solve the above problems, the present inventors have completed the present invention.
That is, the ink for inkjet printing of the present invention comprises (a) conductive powder, (b) a compound having at least one polymerizable unsaturated bond, (c) at least two groups represented by the following formula (1). And (d) a photopolymerization initiator.

[In the formula, * represents a bond. ]
The method for producing an electrode for a flat panel display of the present invention includes a step of forming a pattern by inkjet printing on the substrate using the ink for inkjet printing, and a step of obtaining a cured pattern by irradiating the pattern with energy rays. And a step of firing the cured pattern.

The ink for inkjet printing of the present invention has excellent dispersibility, good filterability during ink preparation, and excellent sedimentation stability after preparation. Therefore, workability improvement at the time of ink preparation and reduction of the number of filter replacements can be expected, so that stable ink discharge performance can be obtained continuously, and nozzle clogging can be suppressed. And according to the ink for inkjet printing of this invention and the manufacturing method of the electrode for FPD using the same, the electrode for FPD which has a highly accurate pattern can be manufactured efficiently.

  Further, in the ink jet method, only ink is ejected to a necessary portion on the substrate to form a member. Therefore, according to the ink for ink jet printing of the present invention and the method for manufacturing an FPD electrode using the ink, Not only can the process be simplified, waste of materials can be eliminated. In addition, it is possible to form a circuit directly by simply connecting a PC on which a CAD is drawn to an ink jet printer, thereby reducing time and cost.

Hereinafter, (1) ink for inkjet printing of the present invention, and (2) a method for producing an electrode for FPD using the ink will be described in detail.
[(1) Ink for inkjet printing]
The ink for inkjet printing of the present invention comprises (a) conductive powder, (b) a compound having at least one polymerizable unsaturated bond (hereinafter also referred to as “(b) polymerizable unsaturated compound”), (c). ) It contains a compound having at least two groups represented by the following formula (1), and (d) a photopolymerization initiator.

[In the formula, * represents a bond. ]
(A) Conductive powder
The (a) conductive powder used in the present invention is not particularly limited, and depends on the usage (type of FPD member), specifications (resistance), etc. of the sintered body formed by ink for inkjet printing. It can be selected appropriately.

  Examples of the conductive powder exhibiting excellent conductivity include gold, silver, copper, platinum, nickel, aluminum, palladium, iron, tin, indium metal fine particles, oxide fine particles thereof, and alloy fine particles. The ink for inkjet printing of the present invention preferably contains at least one of these fine particles.

  In addition, (a) the average particle diameter (D50) of the conductive powder is preferably 0.05 μm or more and 5 μm or less from the viewpoints of ink dispersibility, sedimentation, ejection from an inkjet nozzle, patterning accuracy, and cost.

  In the inkjet printing ink of the present invention, (a) the amount of the conductive powder used is usually 10 to 90% by mass, preferably 30 to 80% by mass, based on the total amount of the inkjet printing ink. .

(B) polymerizable unsaturated compound
As the polymerizable unsaturated compound (b) used in the present invention, a compound having at least one methacryloyl group (CH ₂ ═C (CH ₃ ) —CO—) as the polymerizable unsaturated group (hereinafter referred to as “methacrylic compound”). ), A compound having at least one acryloyl group (CH ₂ ═CH—CO—) (hereinafter referred to as “acrylic compound”), a vinyl group (CH ₂ ═CH—
) And the like (hereinafter referred to as “vinyl compounds”). Said (b) polymerizable unsaturated compound can be used individually or in combination of 2 or more types.

  Here, the advantage of using the (b) polymerizable unsaturated compound is that the pattern formed immediately after the ejection can be maintained by curing the pattern formed by the inkjet ejection with an energy ray such as ultraviolet rays. is there.

  Examples of the methacrylic compound include ethylene glycol dimethacrylate, ethylene glycol monomethacrylate, diethylene glycol dimethacrylate, diethylene glycol monomethacrylate, triethylene glycol dimethacrylate, triethylene glycol monomethacrylate, tetraethylene glycol dimethacrylate, tetraethylene glycol monomethacrylate, 1 , 3-propanediol dimethacrylate, 1,3-propanediol monomethacrylate, 1,4-butanediol dimethacrylate, 1,4-butanediol monomethacrylate, 1,5-pentanediol dimethacrylate, 1,5-pentanediol Monomethacrylate, 1,6-hexanediol dimethacrylate, 1,6-hexanedi It can be exemplified over mono methacrylate, and the like, but is not limited thereto.

  Among these methacrylic compounds, ethylene glycol dimethacrylate, ethylene glycol monomethacrylate, diethylene glycol dimethacrylate, diethylene glycol monomethacrylate, triethylene glycol dimethacrylate, triethylene glycol monomethacrylate, 1,3-propane are low in viscosity. Diol dimethacrylate, 1,3-propanediol monomethacrylate, 1,4-butanediol dimethacrylate, 1,4-butanediol monomethacrylate and the like are preferable, and ethylene glycol dimethacrylate and diethylene glycol dimethacrylate are particularly preferable.

In the present invention, the methacrylic compounds can be used alone or in admixture of two or more.
Examples of the acrylic compound include tetrahydrofurfuryl acrylate, 2-phenoxyethyl acrylate, phenoxydiethylene glycol acrylate, isobornyl acrylate, ethylene glycol diacrylate, ethylene glycol monoacrylate, diethylene glycol diacrylate, diethylene glycol monoacrylate, and triethylene glycol diacrylate. , Triethylene glycol monoacrylate, tetraethylene glycol diacrylate, tetraethylene glycol monoacrylate, polyethylene glycol monoacrylate (5 to 9 structural units derived from ethylene glycol), tripropylene glycol diacrylate, polypropylene glycol diacrylate (proprene) Derived from glycol 5 to 14), 1,3-propanediol diacrylate, 1,3-propanediol monoacrylate, 1,4-butanediol diacrylate, 1,4-butanediol monoacrylate, 1,5-pentane Diol diacrylate, 1,5-pentanediol monoacrylate, 1,6-hexanediol diacrylate, 1,6-hexanediol monoacrylate, dimethylol tricyclodecane diacrylate, monomethylol tricyclodecane monoacrylate, trimethylolpropane Monoacrylate, trimethylolpropane diacrylate, trimethylolpropane triacrylate, pentaerythritol diacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate , Dipentaerythritol pentaacrylate, dipentaerythritol hexaacrylate, ethoxylated pentaerythritol tetraacrylate (tetraacrylate of addition reaction product of pentaerythritol and ethylene oxide), etc. is not.

Of these acrylic compounds, isobornyl acrylate, tetraethylene glycol diacrylate, tetraethylene glycol monoacrylate, polyethylene glycol diacrylate, polyethylene glycol monoacrylate, 1,6-hexanediol are low skin irritation. Diacrylate, 1,6-hexanediol monoacrylate, pentaerythritol tetraacrylate, dipentaerythritol pentaacrylate, dipentaerythritol hexaacrylate, ethoxylated pentaerythritol tetraacrylate, and the like are preferable, especially isobornyl acrylate, tetraethylene glycol diacrylate Acrylate, tetraethylene glycol monoacrylate, polyethylene glycol monoacrylate, Data pentaerythritol tetraacrylate, dipentaerythritol pentaacrylate, dipentaerythritol hexaacrylate, ethoxylated pentaerythritol tetraacrylate are preferred.

In this invention, the said acrylic compound can be used individually or in mixture of 2 or more types.
Examples of the vinyl compound include N-vinylpyrrolidone, N-vinyl-ε-caprolactam, ethylene glycol divinyl ether, ethylene glycol monovinyl ether, diethylene glycol divinyl ether, diethylene glycol monovinyl ether, triethylene glycol divinyl ether, triethylene glycol mono Examples include, but are not limited to, vinyl ether, tetraethylene glycol divinyl ether, tetraethylene glycol monovinyl ether, 2- (2-vinyloxyethoxy) ethyl acrylate, 2- (2-vinyloxyethoxy) ethyl methacrylate, and the like. It is not a thing.

Among these vinyl compounds, N-vinylpyrrolidone, N-vinyl-ε-caprolactam, ethylene glycol divinyl ether, ethylene glycol monovinyl ether, diethylene glycol divinyl ether, diethylene glycol monovinyl ether, triethylene glycol are low in viscosity. Divinyl ether, triethylene glycol monovinyl ether, 2- (2′-vinyloxyethoxy) ethyl acrylate, 2
-(2′-vinyloxyethoxy) ethyl methacrylate and the like are preferable, and in particular, N-vinylpyrrolidone, N-vinyl-ε-caprolactam, diethylene glycol divinyl ether, diethylene glycol monovinyl ether, triethylene glycol divinyl ether, triethylene glycol monovinyl ether, 2- (2-vinyloxyethoxy) ethyl acrylate and 2- (2-vinyloxyethoxy) ethyl methacrylate are preferred.

In the present invention, the vinyl compounds can be used alone or in admixture of two or more.
In the ink for inkjet printing of the present invention, the amount of the (b) polymerizable unsaturated compound used is usually 30 to 300 parts by mass, preferably 50 to 200 parts by mass with respect to 100 parts by mass of the conductive powder (a). Part.

(C) Compound having at least two groups represented by formula (1)
In the present invention, by using (c) a compound having at least two groups represented by the formula (1) (hereinafter, also simply referred to as “(c) compound”), the dispersibility is excellent and the ink is prepared. It is possible to prepare an ink for ink jet printing having good filterability at the time and excellent sedimentation stability after the preparation, and it is possible to obtain a stable ink ejection property continuously. For this reason, the electrode which has a highly accurate pattern can be manufactured efficiently.

  The content of the group represented by the formula (1) in the compound (c) is 2 or more, preferably 2 to 6, and more preferably 2 to 4. When the content of the group represented by the formula (1) is in the above range, the balance between the dispersibility and the storage stability of the ink for inkjet printing is excellent.

  Examples of the compound (c) include trimethylolpropane tris (3-mercaptopropionate), pentaerythritol tetrakis (3-mercaptopropionate), tetraethylene glycol bis (3-mercaptopropionate), dipenta And erythritol hexakis (3-mercaptopropionate).

In this invention, (c) compound can be used individually or in mixture of 2 or more types.
In the ink for inkjet printing of the present invention, the amount of the compound (c) used is usually 0.1 to 30 parts by weight, preferably 0.5 to 20 parts by weight, based on 100 parts by weight of the conductive powder (a). Part.

(D) Photopolymerization initiator
Examples of the photopolymerization initiator (d) used in the present invention include benzyl, benzoin, benzophenone, camphorquinone, 2,2-dimethoxy-1,2-diphenylethane-1-one, 4,4′-bis ( Dimethylamino) benzophenone, 4,4′-bis (diethylamino) benzophenone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1-hydroxycyclohexyl phenyl ketone, 2,2-dimethoxy-2-phenylacetophenone 2-methyl-1- [4 ′-(methylthio) phenyl] -2-morpholinopropan-1-one, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butane-1- Carbonyl compounds such as ON;
Azoisobutyronitrile, 4-azidobenzaldehyde, ethanone-1- [9-ethyl-6- [2-methyl-4- (2,2-dimethyl-1,3-dioxolanyl) methoxybenzoyl] -9. H. An azo compound or an azide compound such as -carbazol-3-yl] -1- (O-acetyloxime);
Organic sulfur compounds such as 2-mercaptobenzothiazole and mercaptan disulfide;
Organic peroxides such as benzoyl peroxide, di-tert-butyl peroxide, tert-butyl hydroperoxide, cumene hydroperoxide, paraffin hydroperoxide;
1,3-bis (trichloromethyl) -5- (2′-chlorophenyl) -1,3,5-triazine, 2- [2- (2-furanyl) ethylenyl] -4,6-bis (trichloromethyl)- Trihalomethanes such as 1,3,5-triazine;
Imidazole dimers such as 2,2′-bis (2-chlorophenyl) 4,5,4 ′, 5′-tetraphenyl 1,2′-biimidazole;
Thioxanthone compounds such as 2-isopropylthioxanthone, 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, 2,4-dichlorothioxanthone;
Phosphine oxide compounds such as 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide;
Examples include O-acyl oxime compounds such as 1,2-octanedione, 1- [4- (phenylthio)-, 2- (O-benzoyloxime)].

In the present invention, the photopolymerization initiator (d) can be used alone or in admixture of two or more.
In the ink for inkjet printing of the present invention, the amount of the (d) photopolymerization initiator used is usually 0.1 to 30 parts by mass, preferably 0 with respect to 100 parts by mass of the (b) polymerizable unsaturated compound. .5 to 20 parts by mass.

(E) Optional component
The ink for inkjet printing of the present invention may contain a binder glass for the purpose of increasing the adhesion to the substrate after firing and the mechanical strength of the structure.

Moreover, the ink for inkjet printing of this invention may contain the solvent and plasticizer for viscosity adjustment, an acrylic resin, and a cellulose resin.
In addition, a silane coupling agent for improving adhesion to the substrate, a dispersant other than the compound (c) aimed at improving dispersibility and suppressing sedimentation, an adhesion assistant, an antihalation agent, a leveling agent, a storage stabilizer, Various additives such as an antifoaming agent, an antioxidant, an ultraviolet absorber, a sensitizer, a tackifier, a surface tension modifier, and a drying inhibitor may be contained.

  Examples of the binder glass include glass powder having a softening point in the range of 350 to 700 ° C, preferably 400 to 620 ° C. When the softening point of the glass powder is below the lower limit of the above range, the glass in the stage where the organic material such as the plasticizer is not completely decomposed and removed in the firing process of the ink film for ink jet printing with the ink containing the glass powder. The powder may melt. Therefore, a part of the organic substance remains in the formed member, and as a result, there is a possibility that the resistance value increases. On the other hand, when the softening point of the glass powder exceeds the upper limit of the above range, since it is necessary to fire at a high temperature, distortion or the like is likely to occur in a glass substrate or the like that is a printing material.

Specific examples of suitable glass powder include
1. A mixture of lead oxide, boron oxide, silicon oxide (PbO—B ₂ O ₃ —SiO ₂ system),
2. A mixture of zinc oxide, boron oxide, silicon oxide (ZnO—B ₂ O ₃ —SiO ₂ system),
3. Lead oxide, boron oxide, silicon oxide, aluminum oxide (PbO—B ₂ O ₃ —SiO ₂ —
A mixture of Al ₂ O ₃ system),
4). A mixture of lead oxide, zinc oxide, boron oxide, silicon oxide (PbO—ZnO—B ₂ O ₃ —SiO ₂ system),
5. A mixture of bismuth oxide, boron oxide, silicon oxide (Bi ₂ O ₃ —B ₂ O ₃ —SiO ₂ system),
6). A mixture of zinc oxide, phosphorus oxide, silicon oxide (ZnO—P ₂ O ₅ —SiO ₂ system),
7). A mixture of zinc oxide, boron oxide, potassium oxide (ZnO—B ₂ O ₃ —K ₂ O system),
8). A mixture of phosphorus oxide, boron oxide, aluminum oxide (P ₂ O ₅ —B ₂ O ₃ —Al ₂ O ₃ system),
9. Zinc oxide, phosphorus oxide, silicon oxide, aluminum oxide (ZnO—P ₂ O ₅ —SiO ₂ —
A mixture of Al ₂ O ₃ system),
10. A mixture of zinc oxide, phosphorus oxide, titanium oxide (ZnO—P ₂ O ₅ —TiO ₂ system),
11. Zinc oxide, boron oxide, silicon oxide, potassium oxide (ZnO—B ₂ O ₃ —SiO ₂ —
K ₂ O-based) mixture,
12 A mixture of zinc oxide, boron oxide, silicon oxide, potassium oxide, calcium oxide (ZnO—B ₂ O ₃ —SiO ₂ —K ₂ O—CaO system),
13. Examples thereof include a mixture of zinc oxide, boron oxide, silicon oxide, potassium oxide, calcium oxide, and aluminum oxide (ZnO—B ₂ O ₃ —SiO ₂ —K ₂ O—CaO—Al ₂ O ₃ system).

The glass powder preferably has an average particle diameter (D50) of 0.1 to 5 μm.
Moreover, it is preferable that the addition amount of the said glass powder is 0-20 mass parts with respect to 100 mass parts of (a) electroconductive powder.

  The ink for inkjet printing of the present invention comprises (a) a conductive powder, (b) a polymerizable unsaturated compound, (c) a compound, and (d) a photopolymerization initiator, and optionally (e) The components can be prepared by kneading using a kneader such as a roll kneader, mixer, homomixer, ball mill, or bead mill.

  The ink for inkjet printing prepared as described above is an ink-like composition having fluidity suitable for ejection by inkjet, and its viscosity is usually 1 to 1000 cP, preferably 3 to 100 cP at 25 ° C. Is done.

  The ink for ink jet printing of the present invention can be used for any type of ink jet without being particularly limited, such as a piezo type, a bubble jet (registered trademark) type, and a beam jet type.

The ink for inkjet printing of the present invention can be suitably used for the production of members that require electrical conductivity, particularly for the production of FPD electrodes such as PDP electrodes.
[(2) FPD electrode manufacturing method]
Hereinafter, the manufacturing method of the electrode for FPD using the ink for inkjet printing of this invention is demonstrated.

  The manufacturing method of the electrode for FPD of the present invention includes: [1] a step of forming a pattern by inkjet printing on the substrate using the ink for inkjet printing; [2] a cured pattern by irradiating the pattern with energy rays. And [3] baking the cured pattern. In the present invention, “energy rays” means visible rays, ultraviolet rays, far ultraviolet rays, X rays, electron rays, molecular rays, γ rays, synchrotron radiation, proton beam rays, and the like.

Hereinafter, each process in the bus electrode formation process on the front substrate of the PDP will be described. Other electrodes can be manufactured by basically the same method.
-Process [1]-
In this step, a pattern is formed on a substrate which is a printing material by inkjet printing using the inkjet printing ink of the present invention.

  The formation of the pattern in this step can be performed according to a known ink-jet pattern formation method. For example, by ejecting ink from an inkjet head while moving the glass substrate or inkjet head on a transparent electrode formed on a glass substrate (for example, PD200 manufactured by Asahi Glass) that is a printing material, Form the desired pattern. At this time, the drawing time is shortened by increasing the number of nozzles, and the electrodes can be formed efficiently.

  In this step, the ink for inkjet printing and the nozzle head are maintained at a constant temperature of, for example, usually 10 to 100 ° C., preferably 15 to 60 ° C. so that stable continuous ejection is possible.

Moreover, the discharge amount of the ink for inkjet printing from a nozzle is 2-15 picoliter / second normally, for example, Preferably it is 4-12 picoliter / second.
-Step [2]-
In this step, a cured pattern is formed by irradiating the pattern with energy rays and exposing the pattern.

  Curing by exposure is usually performed for 0.001 to 2.0 seconds, preferably 0.001 to 1.0 seconds after landing of the ink for inkjet printing. In order to perform high-definition printing, it is desirable to perform exposure immediately after landing of the ink for inkjet printing.

As the energy ray, ultraviolet rays or visible rays having a wavelength of usually 200 to 500 nm, preferably 240 to 420 nm are used. The exposure amount is usually 1 to 1000 mJ / cm ² . As an exposure method, for example, a method described in Japanese Patent Application Laid-Open No. 60-132767 and US Pat. No. 6,145,579, more specifically, a shuttle method or a fiber method can be employed.

  When printing, it may be printed in a single layer or in multiple layers. In addition, when printing in a multi-layered stack, it is desirable to cure with an energy beam after each layer is printed.

-Process [3]-
In this step, the cured pattern is baked. In this step, since the inorganic powder-containing resin pattern layer, which is a cured pattern layer, is baked, the organic material remaining in the inorganic powder-containing resin pattern layer is burned off to form an electrode.

  The temperature of the baking treatment needs to be a temperature at which the organic substance in the residual portion of the inorganic powder-containing resin layer is burned off, and is usually 400 to 600 ° C. The firing time is usually 10 to 90 minutes.

Examples of the present invention will be described below, but the present invention is not limited to these examples. In the following, “part” means “part by mass”.
-Filterability-
As for the filterability of the ink, it is filtered by pressure feeding using a SUS 2000 mesh filter (reference value of passing particle sphere 12 μm), and the filterability is good when the number of times of clogging is 0 to 1 (◯). When the number of clogging was 2 to 3 times, the filterability was slightly bad (Δ), and when the number of clogging was 4 times or more, the filterability was poor (x).

-Sedimentation stability-
In addition, regarding the sedimentation stability of the ink, after the ink obtained was filled in a sample bottle and sealed, the sedimentation condition when allowed to stand at room temperature for 3 days was evaluated. In the present invention, the sedimentation could not be completely suppressed. Among them, the sedimentation stability is good (◯), and the first to the third days when the conductive particles are suspended in the ink supernatant for the first time after three days. The sedimentation stability was evaluated in three stages: sedimentation stability was slightly poor (Δ), and sedimentation was completely settled within one day, and sedimentation stability was poor (x).

-Viscosity-
The viscosity of the ink was measured using an E-type clay meter at a temperature of 25 ° C. and a rotation speed of 20 rpm.

[Example 1]
(A) 100 parts of silver powder (average particle size (D50) 0.5 μm) as the conductive powder, (b) 100 parts of N-vinylpyrrolidone, 100 parts of tripropylene glycol diacrylate as the polymerizable unsaturated compound, ( c) 5 parts of tetraethylene glycol bis (3-mercaptopropionate) as the compound, and (d) 2-methyl-1- [4 ′-(
4 parts of methylthio) phenyl] -2-morpholinopropan-1-one and 2 parts of 2,4-diethylthioxanthone were kneaded using a disperser to obtain an ink for ink jet printing. The viscosity of the ink at 25 ° C. was 9.3 cP.

[Example 2]
(A) 100 parts of silver powder (average particle size (D50) 0.5 μm) as the conductive powder, (b) 100 parts of N-vinylpyrrolidone, 100 parts of tripropylene glycol diacrylate as the polymerizable unsaturated compound, ( c) 5 parts of pentaerythritol tetrakis (3-mercaptopropionate) as the compound, and (d) 2-methyl-1- [4 ′-(methylthio) phenyl] -2-morpholinopropane-1 as the photopolymerization initiator -4 parts of ON and 2 parts of 2,4-diethylthioxanthone were kneaded using a disperser to obtain an ink for ink jet printing. The viscosity of the ink at 25 ° C. was 9.4 cP.

[Comparative Example 1]
(A) 100 parts of silver powder (average particle size (D50) 0.5 μm) as the conductive powder, (b) 100 parts of N-vinylpyrrolidone, 100 parts of tripropylene glycol diacrylate as the polymerizable unsaturated compound, ( d) 2 parts of 2-methyl-1- [4 ′-(methylthio) phenyl] -2-morpholinopropan-1-one, 1 part of 2,4-diethylthioxanthone as a photopolymerization initiator, β- Using 5 parts of mercaptopropionic acid, these were kneaded using a disperser to obtain an ink for inkjet printing. The viscosity of the ink at 25 ° C. was 8.8 cP.

[Comparative Example 2]
(A) 100 parts of silver powder (average particle size (D50) 0.5 μm) as the conductive powder, (b) 100 parts of N-vinylpyrrolidone, 100 parts of tripropylene glycol diacrylate as the polymerizable unsaturated compound, ( d) 2 parts of 2-methyl-1- [4 ′-(methylthio) phenyl] -2-morpholinopropan-1-one, 1 part of 2,4-diethylthioxanthone as a photopolymerization initiator, 2- Using 5 parts of ethylhexyl-3-mercaptopropionate, these were kneaded using a disperser to obtain an ink for inkjet printing. The viscosity of the ink at 25 ° C. was 9.3 cP.

[Comparative Example 3]
(A) 100 parts of silver powder (average particle size (D50) 0.5 μm) as the conductive powder, (b) 100 parts of N-vinylpyrrolidone, 100 parts of tripropylene glycol diacrylate as the polymerizable unsaturated compound, ( d) 2 parts of 2-methyl-1- [4 ′-(methylthio) phenyl] -2-morpholinopropan-1-one, 1 part of 2,4-diethylthioxanthone as a photopolymerization initiator, 1, Using 5 parts of 6-hexanedithiol, these were kneaded using a disperser to obtain an ink for inkjet printing. The viscosity of the ink at 25 ° C. was 8.9 cP.

[Comparative Example 4]
(A) 100 parts of silver powder (average particle size (D50) 0.5 μm) as the conductive powder, (b) 100 parts of N-vinylpyrrolidone, 100 parts of tripropylene glycol diacrylate as the polymerizable unsaturated compound, ( d) 2 parts of 2-methyl-1- [4 ′-(methylthio) phenyl] -2-morpholinopropan-1-one, 1 part of 2,4-diethylthioxanthone as a photopolymerization initiator, 1- Using 5 parts of pentanethiol, these were kneaded using a disperser to obtain an ink for inkjet printing. The viscosity of the ink at 25 ° C. was 8.8 cP.

[Comparative Example 5]
(A) 100 parts of silver powder (average particle size (D50) 0.5 μm) as the conductive powder, (b) 100 parts of N-vinylpyrrolidone, 100 parts of tripropylene glycol diacrylate, d) Disperser using 2 parts of 2-methyl-1- [4 ′-(methylthio) phenyl] -2-morpholinopropan-1-one and 1 part of 2,4-diethylthioxanthone as a photopolymerization initiator These were kneaded to obtain ink for inkjet printing. The viscosity of the ink at 25 ° C. was 8.8 cP.

  Table 1 shows the evaluation results of the inks for inkjet printing obtained in Examples and Comparative Examples. In Table 1, a compound having a group represented by the formula (1) is described as a β-mercaptopropionic acid derivative.

[Example 3]
Using the inkjet printing ink obtained in Example 1, using an inkjet patterning apparatus (MicroPrint, NanoPrinter-1500S) and a nozzle head having a nozzle diameter of 35 μm (Dimatix SE-128), a glass substrate The ink was discharged on top and a linear conductive pattern was printed. Then, the mixed light of g line (436 nm), h line (405 nm), and i line (365 nm) was irradiated with the ultrahigh pressure mercury lamp. The exposure amount at that time was 20 mJ / cm ^{2 in} terms of illuminance measured by a 365 nm sensor.
When the pattern after exposure was observed with a scanning electron microscope, it was confirmed that a fine pattern having a line width of 75 μm and a height of 5 μm was obtained.

[Example 4]
The same procedure as in Example 3 was performed except that the ink for inkjet printing obtained in Example 2 was used. When the pattern after exposure was observed with a scanning electron microscope, it was confirmed that a fine pattern having a line width of 75 μm and a height of 5 μm was obtained.

Claims (2)

(A) conductive powder, (b) a compound having at least one polymerizable unsaturated bond, (c) a compound having at least two groups represented by the following formula (1), and (d) a photopolymerization initiator. An ink for ink jet printing, comprising:

[In the formula, * represents a bond. ] Forming a pattern by ink jet printing on the substrate using the ink for ink jet printing according to claim 1,
Irradiating the pattern with energy rays to obtain a cured pattern; and firing the cured pattern;
The manufacturing method of the electrode for flat panel displays characterized by including these.