KR101681025B1 - Photosensitive conductive paste composition - Google Patents

Abstract

The present invention relates to a photosensitive conductive paste composition, which comprises (a) a conductive metal powder, (b) an acrylate photosensitive binder having an unsaturated double bond, (c) a siloxane photosensitive crosslinking agent having a polyfunctional group, (d) a dispersant, (e) a photoinitiator, and (f) a solvent. Thus, the photosensitive conductive paste composition according to the present invention can be formed by chemically bonding a glass substrate with a siloxane photosensitive crosslinking agent in combination with a glass substrate in the form of a -Si-O-form upon thermal activation, without using the acrylate photosensitive binder resin alone The adhesion of the pattern electrode can be improved. The photosensitive conductive paste composition according to the present invention can exhibit high resolution, low contact resistance, excellent storage stability and electrical resistivity.

Description

[0001] PHOTOSENSITIVE CONDUCTIVE PASTE COMPOSITION [0002]

The present invention relates to a photosensitive conductive paste composition, and more particularly, to a photosensitive conductive paste composition having alkali solubility capable of realizing an electrode pattern of fine line width on a touch panel and capable of improving adhesion to a substrate.

As the IT industry, the display industry and the semiconductor industry have developed into convergence technologies, the technology of touch screen panel (TSP) has rapidly developed, making the panel slimmer, lighter and more highly integrated. These touch screen panel technologies are making remarkable progress with the growth of touch phones and tablet PCs centered on smart phones, and are attracting attention as new growth engines due to simple design, easy and realistic manipulation

A touch screen panel, also abbreviated to a touch panel, is a device that touches a person's hand or pen to a character or specific position displayed on the screen and processes a specific function according to the contacted position, without a separate input device such as a mouse or a keyboard .

The touch panel consists largely of i) a top plate film on which a transparent conductive thin film such as indium oxide (ITO) is deposited and a lower plate film (or glass), which detects input coordinates according to presence or absence of input touching the screen, A controller IC for converting a signal transmitted from the touch panel to a digital signal and outputting the signal to a display on the display, and iii) a drive software for receiving the signal received from the controller IC and appropriately implementing the touch screen panel.

In order to operate the touch panel, a patterned sensor electrode on a substrate and a wiring electrode for transmitting an electrical signal from the sensor electrode to the controller IC are required.

An indium tin oxide (ITO) electrode having excellent transparency is mainly used for the sensor electrode, and a conductive paste such as silver (Ag) paste is used for the wiring electrode.

Conventionally, as a method of forming a pattern on the wiring electrode, a photosensitive conductive paste is prepared by mixing a conductive powder, a photo-curable resin such as an acrylate, a monomer, a photoinitiator and a solvent. However, the electrode formed by curing the photosensitive conductive paste by using UV has a disadvantage in that it is not excellent in adhesion to a glass substrate or a silicon substrate.

Further, when used alone as an acrylate resin, there is a disadvantage in that the adhesive force with the substrate is not sufficient. In the case of using an acrylate resin or a monomer, there is the disadvantage that the pattern electrode is cracked due to abrupt shrinkage of the paste during the photo-curing reaction or peeled off from the substrate (or substrate).

The present invention provides a photosensitive conductive paste composition having improved adhesion to a substrate.

The present invention provides a photosensitive conductive paste composition capable of forming an electrode pattern having high resolution, low contact resistance, storage stability and low specific resistance.

The present invention is to provide a photosensitive conductive paste composition capable of forming an electrode pattern having a fine line width even by a simple process of directly exposing after screen printing.

(C) a siloxane-based photosensitive crosslinking agent having a polyfunctional group; (d) a dispersing agent; and (d) a dispersing agent. The photosensitive conductive paste composition according to the present invention comprises (e) a photoinitiator and (f) a solvent.

The acrylate-based photosensitive binder has an unsaturated double bond. The siloxane photosensitive crosslinking agent includes a first repeating unit represented by the following formula (1), a second repeating unit represented by the following formula (2), and a third repeating unit represented by the following formula (3).

[Chemical Formula 1]

(2)

(3)

Wherein R1 is -CH = CH2 or -CH2CH2CH2OOCC (CH3) = CH2, R2 is -CH3 or -OCH3, and R3 is -OCH3 or -OCH2CH3.

According to an embodiment of the present invention, the conductive metal powder comprises 70 to 90% by weight of the conductive metal powder, 1 to 20% by weight of the acrylate photosensitive binder, 4 to 10% by weight of the siloxane photosensitive crosslinking agent, 0.1 to 3% To 3% by weight and an excess of solvent.

According to one embodiment, the siloxane photosensitive cross-linking agent is used in an amount of 10 to 30 mol% for the first recurring unit and 30 to 50 mol% for the second recurring unit based on the total number of moles of the first to third repeating units. Mol% and the third repeating unit in an amount of 20 to 60 mol%.

According to one embodiment, the acrylate-based photosensitive binder may be represented by the following general formula (4).

[Chemical Formula 4]

Wherein R is -CH = CH2 or -CH2CH2CH2OOCC (CH3) = CH2, R2 is -CH3 or -OCH3, R3 is -OCH3 or -OCH2CH3, a is from 10 to 30, b is from 30 to 50, c is 20 to 60, and a + b + c = 100.

According to one embodiment, the conductive metal powder may include at least one selected from the group consisting of silver (Ag), gold (Au), cobalt (Co), nickel (Ni), and copper (Cu).

According to one embodiment, the conductive metal powder may have at least one shape selected from the group consisting of spherical, angular, and plate shapes.

According to one embodiment, the conductive metal powder may be a mixture of two or more metal powders having different average particle diameters (D50).

The photosensitive conductive paste composition according to the present invention may be used in combination with a siloxane photosensitive crosslinking agent in combination with a patterned electrode formed by chemical bonding with a glass substrate in the form of -Si-O- Can be improved. The photosensitive conductive paste composition according to the present invention can exhibit high resolution, low contact resistance, excellent storage stability and electrical resistivity.

In addition, since the photosensitive conductive paste composition according to the present invention can be patterned by utilizing screen printing, time and cost can be saved in terms of the manufacturing process as compared with the conventional thin film photolithography method.

Fig. 1 is a photograph showing the line width (20 占 퐉 / 20 占 퐉) of wiring electrodes of a touch panel using the photosensitive conductive paste composition according to Example 1. Fig.
2 is a photograph before and after the adhesion tests of Examples 1 to 4 and Comparative Example 1. Fig.

The photosensitive conductive paste composition according to one embodiment of the present invention is a photosensitive conductive paste composition comprising (a) a conductive metal powder, (b) an acrylate-based photosensitive binder having an unsaturated double bond, (c) a siloxane photosensitive crosslinking agent having a polyfunctional group, (d) , (e) a photoinitiator, and (f) a solvent.

Hereinafter, each component contained in the photosensitive conductive paste composition according to the present invention will be described in detail.

(a) a conductive metal powder

The conductive metal powder used in the present invention may be an inorganic conductive metal powder that can be used in a display device. Such an inorganic conductive metal powder is for imparting conductivity to an electrode paste of a display element such as a touch panel. As the conductive powder, for example, one or more metal powders may be used.

For example, the conductive metal powder may be silver (Ag), gold (Au), cobalt (Co), nickel (Ni), copper (Cu), or a combination thereof.

The content of the conductive metal powder is preferably 70 wt% to 90 wt% with respect to the total weight of the photosensitive conductive paste composition, and when the content is less than 70 wt%, it is difficult to achieve the conductivity required for the touch panel On the other hand, if it exceeds 90% by weight, the dispersibility may be lowered or the ultraviolet curing may not be sufficiently performed.

The average particle diameter (D50) of the conductive metal powder may be 0.5 to 3 占 퐉. When the average particle diameter (D50) is less than 0.5 占 퐉, the contact probability between the metal powders is lowered, Probability can be increased. On the other hand, if it exceeds 3 탆, the surface smoothness, pattern accuracy, and dimensional accuracy of the pattern after printing may be lowered.

The conductive metal powder may be a mixture of two or more metal powders having different average particle sizes (D50). For example, the following spherical powder (A), spherical powder (B), angular powder (C), square powder (D), plate powder (E) and plate powder (F) Two or more mixed powders having different particle diameters (D50) may be used.

The conductive metal powder used in the present invention may have various shapes such as spherical, angular, and plate shapes. At this time, the average particle diameter range of each of the conductive metal powders to be mixed is not limited. That is, it is also possible to mix a nano-sized conductive metal powder having a small average particle size and a conductive metal powder having a size of a few microns.

Spherical powder (A):

Average particle diameter (D10) of 1.0 to 1.5 占 퐉, average particle diameter (D50) of 1.5 to 2.5 占 퐉, average particle diameter (D90) of 4.0 to 5.0 占 퐉.

Spherical powder (B):

Average particle diameter (D10) of 1.5 to 2.0 占 퐉, average particle diameter (D50) of 2.0 to 3.0 占 퐉, average particle diameter (D90) of 4.5 to 6.5 占 퐉.

Square powder (C):

Average particle diameter (D10) of 0.5 to 1.5 占 퐉, average particle diameter (D50) of 1.5 to 2.5 占 퐉, average particle diameter (D90) of 4.0 to 6.0 占 퐉.

Square powder (D):

Average particle diameter (D10) of 1.5 to 2.5 占 퐉, average particle diameter (D50) of 2.5 to 3.5 占 퐉, average particle diameter (D90) of 6.0 to 8.0 占 퐉.

Plate Type Powder (E):

Average particle diameter (D10) of 0.2 to 1.0 占 퐉, average particle diameter (D50) of 1.0 to 1.5 占 퐉, average particle diameter (D90) of 1.5 to 2.5 占 퐉.

Plate Type Powder (F):

An average particle diameter (D10) of 1.0 to 1.5 占 퐉, an average particle diameter (D50) of 2.0 to 3.0 占 퐉, and an average particle diameter (D90) of 4.5 to 5.5 占 퐉.

Here, D10, D50, and D90 mean the average diameter of the particles corresponding to cumulative volumes of 10 vol%, 50 vol%, and 90 vol% in the cumulative distribution curve, respectively.

(b) an acrylate-based photosensitive binder

The acrylate-based photosensitive binder is cured by intermolecular crosslinking under the action of active energy such as ultraviolet rays, electron beams and the like to form a cured film.

The content of the acrylate-based photosensitive binder is preferably 1 to 20 wt%, more preferably 7 to 11 wt%, based on the total weight of the photosensitive conductive paste composition. When the content is less than 1% by weight, the developability deteriorates and patterning due to development may be difficult. On the other hand, when the content exceeds 20% by weight, the proportion of the conductive metal powder is relatively insufficient and the specific resistance may be increased. The content of the acrylate-based photosensitive binder is based on the nonvolatile component (solid content).

The weight average molecular weight of the acrylate-based photosensitive binder is preferably 1,000 to 100,000. When the weight average molecular weight is less than 1,000, the adhesion of the coating film at the time of development deteriorates. On the other hand, when the weight average molecular weight exceeds 100,000, defective development tends to occur. And more preferably from 5,000 to 70,000. In addition, the weight average molecular weight is a value in terms of polystyrene measured by gel permeation chromatography (GPC).

On the other hand, the acid value of the acrylate-based photosensitive binder according to the present invention is preferably 40 to 150 mgKOH / g, and when the acid value is less than 40 mgKOH / g, the solubility in an aqueous alkaline solution is insufficient, On the other hand, if it exceeds 150 mgKOH / g, the adhesion of the coating film may deteriorate during development or dissolution of the photocured portion (exposed portion) may occur.

The glass transition temperature of the acrylate-based photosensitive binder is preferably 20 to 120 ° C. When the glass transition temperature is less than 20 ° C, the shape stability of the binder may be deteriorated. If the glass transition temperature is more than 120 ° C You may lose your sex.

As the acrylate-based photosensitive binder, a resin having a photosensitive group such as an ethylenically unsaturated bond such as a vinyl group, an allyl group, an acryloyl group or a methacryloyl group, or a propargyl group, for example, a resin having an ethylenic unsaturated group in its side chain Various known photosensitive resins (photosensitive prepolymers) such as acrylic copolymers, unsaturated carboxylic acid-modified epoxy resins or resins obtained by addition of polybasic acid anhydrides thereto may be used.

These photocurable organic binders can be used in combination with a compound having at least one ethylenic unsaturated bond in the molecule, that is, a multifunctional photopolymerizable crosslinking agent to be described later. The photocurable organic binder is preferably used in combination with a photopolymerization initiator, which will be described later, in order to promote the photopolymerization more efficiently.

When the resin is used in the photolithography method, a resin having a carboxyl group is particularly preferable from the viewpoint of developability. Specific examples of such a resin having a carboxyl group (which may be an oligomer or a polymer) include the following.

(1) a carboxyl group-containing resin obtained by copolymerizing an unsaturated carboxylic acid such as (meth) acrylic acid with a compound having an unsaturated double bond such as methyl (meth)

(Meth) acrylate, (meth) acrylic acid chloride or the like to a copolymer of an unsaturated carboxylic acid such as (meth) acrylic acid and a compound having an unsaturated double bond such as methyl (meth) A carboxyl group-containing photosensitive resin obtained by adding an unsaturated group as a pendant

(3) To a copolymer of a compound having an unsaturated double bond with an epoxy group such as glycidyl (meth) acrylate and a compound having an unsaturated double bond such as methyl (meth) acrylate, an unsaturated carboxyl group such as (meth) Containing acid labile group is reacted with an acid, and a produced secondary hydroxyl group is reacted with a polybasic acid anhydride such as tetrahydrophthalic anhydride.

(4) a compound having a hydroxyl group and an unsaturated double bond such as 2-hydroxyethyl (meth) acrylate in a copolymer of an acid anhydride having an unsaturated double bond such as maleic anhydride and a compound having an unsaturated double bond such as styrene Containing photosensitive resin < RTI ID = 0.0 >

(5) a carboxyl group-containing photosensitive resin obtained by reacting a polyfunctional epoxy compound with an unsaturated carboxylic acid such as (meth) acrylic acid and reacting the produced secondary hydroxyl group with a polybasic acid anhydride such as tetrahydrophthalic anhydride

(6) An organic acid having one carboxyl group per molecule and no ethylenic unsaturated bond in the epoxy group of a copolymer of a compound having an unsaturated double bond such as methyl (meth) acrylate and glycidyl (meth) acrylate is reacted Containing hydroxyl group and reacting the produced secondary hydroxyl group with a polybasic acid anhydride to obtain a carboxyl group-containing photosensitive resin

(7) a carboxyl group-containing resin obtained by reacting a hydroxyl group-containing polymer such as polyvinyl alcohol with a polybasic acid anhydride

Among them, resins of (1), (2), (3) and (6) can be preferably used. These resins may be used alone or in combination. In the present specification, (meth) acrylate is generically referred to as acrylate, methacrylate and a mixture thereof, and the same applies to other similar expressions.

As the alkali-soluble photosensitive binder, an acrylic copolymer can be polymerized and used. The acrylic copolymer is a copolymer containing at least one kind of acrylic monomer in the copolymerization component. As specific examples of the acrylic monomer, all compounds having a carbon-carbon double bond can be used, and preferred examples thereof include methyl acrylate, methyl methacrylate, ethyl acrylate, acrylic acid, methacrylic acid, 2-ethylhexyl acrylate, methacryl But are not limited to, methyl ethyl, n-butyl acrylate, i-butyl acrylate, i-propane acrylate, benzyl methacrylate, cyclohexyl methacrylate, glycidyl acrylate, glycidyl methacrylate, Acrylamide, N-ethoxymethylacrylamide, N-butoxymethylacrylamide, N-isobutoxymethyl acrylamide, butoxy triethylene glycol acrylate, dicyclopentanyl acrylate, dicyclopentenyl acrylate, 2- Hydroxyethyl acrylate, isobornyl acrylate, 2-hydroxypropyl acrylate, isodecyl acrylate, isooctyl acrylate Acrylates such as methacrylic acid, methacrylic acid, methacrylic acid, methacrylic acid, methacrylic acid, methacrylic acid, methacrylic acid, methacrylic acid, Acrylic monomers such as ethyl acrylate, acrylamide, aminoethyl acrylate, phenyl acrylate, phenoxy ethyl acrylate, 1-naphthyl acrylate, 2-naphthyl acrylate, thiophenol acrylate and benzyl mercaptan acrylate And those obtained by replacing these acrylates with methacrylates, styrenes such as styrene, p-methylstyrene, o-methylstyrene, m-methylstyrene,? -Methylstyrene, chloromethylstyrene and hydroxymethylstyrene,? -Methacryl Propyl trimethoxysilane, 1-vinyl-2-pyrrolidone, and the like.

In the present invention, it is preferable to use acrylic acid, methacrylic acid, methyl methacrylate, methyl acrylate, ethyl acrylate, n-butyl acrylate, i-butyl acrylate, benzyl methacrylate, cyclohexyl methacrylate, styrene, glycidyl Acrylate copolymer was polymerized by using a monomer such as methacrylate, and the paste was applied to the paste to secure the characteristics of the paste and the wiring electrode.

(c) a multifunctional siloxane-based photosensitive crosslinking agent

When the polyfunctional siloxane photosensitive crosslinking agent is activated by heat, it can chemically bond with the glass substrate in the form of -Si-O-, thereby improving the adhesion of the electrode.

The content of the polyfunctional siloxane photosensitive crosslinking agent is preferably 4 to 10% by weight, more preferably 4 to 8% by weight based on the total weight of the photosensitive conductive paste composition. When the content of the photosensitive crosslinking agent is less than 4% by weight, the density of the curing of the exposure pattern may be weakened. On the other hand, if the content of the photosensitive crosslinking agent is more than 10% by weight, pattern characteristics may be deteriorated. .

The multifunctional siloxane photosensitive crosslinking agent may include a first repeating unit represented by the following formula (1), a second repeating unit represented by the following formula (2), and a third repeating unit represented by the following formula (3).

[Chemical Formula 1]

(2)

(3)

Wherein R1 is -CH = CH2 or -CH2CH2CH2OOCC (CH3) = CH2, R2 is -CH3 or -OCH3, and R3 is -OCH3 or -OCH2CH3.

For example, the multifunctional siloxane photosensitive crosslinking agent may contain 10 to 30 mol% of the first repeating unit and 30 to 50 mol% of the second repeating unit, based on the total moles of the first to third repeating units % And the third repeating unit in an amount of 20 to 60 mol%. For example, the multifunctional siloxane photosensitive crosslinking agent may be a compound represented by the following general formula (4).

[Chemical Formula 4]

Wherein a is 10 to 30, b is 30 to 50, c is 20 to 60, and a and b are the same as defined in the above Chemical Formulas 1 to 3, The order of arrangement of the first to third repeating units included in Formula 4 is not limited and may be randomly arranged or arranged in blocks. In the present specification, "*" means a connecting portion between repeating units.

For example, the weight average molecular weight of the polyfunctional siloxane photosensitive crosslinking agent may be 1,000 to 5,000.

For example, the multifunctional siloxane photosensitive crosslinking agent included in the conductive paste composition of the present invention may be at least one selected from the group consisting of vinyltrimethoxysilane, vinyltriethoxysilane, vinylbutyltriethoxysilane, vinyltri (beta-methoxy) silane, But are not limited to, vinyltri (beta-ethoxy) silane, acryloxypropyltrimethoxysilane, acryloxypropyltriethoxysilane, acryloxypropylmethyldimethoxysilane, gamma-methacryloxypropyltrimethoxysilane, gamma-methacryloxy Methacryloxypropylmethyldimethoxysilane, gamma-methacryloxypropylmethyldiisopropoxysilane, gamma-methacryloxybutyltrimethoxysilane tetramethoxysilane, tetraethoxysilane, tetraethoxysilane, , Tetrapropoxysilane, tetraisopropoxysilane, tetra-n-butoxysilane, tetra-sec-butoxysilane, tetra-tert-butoxysilane, methyltrimethoxysilane, Methyltriethoxysilane, methyltriethoxysilane, ethyltrimethoxysilane, ethyltriisopropoxysilane, ethyltributoxysilane, butyltrimethoxysilane, phenyltrimethoxysilane, 3-methyltrimethoxysilane , Dimethyldimethoxysilane, diphenyldimethoxysilane, dibutyldimethoxysilane, trimethyldimethoxysilane, trimethylethoxysilane, tributylmethoxysilane, tributylethoxysilane, trifluoromethyltrimethoxysilane, But are not limited to, trifluoromethyltriethoxysilane, trifluoromethyltriethoxysilane, trifluoropropyltrimethoxysilane, trifluoropropyltriethoxysilane, nonafluorobutylethyltrimethoxysilane, nonafluorobutylethyltriethoxysilane, nonafluoro Hexyltrimethoxysilane, nonafluorohexyltriethoxysilane, tridecafluorooctyltrimethoxysilane, tridecafluorooctyltriethoxysilane, heptadecafluorodecyltrimethoxysilane, heptadecafluorodecyltrimethoxysilane, heptadecafluorodecyltrimethoxysilane, Heptadecafluorodecyltriisopropylsilane, 3-trimethoxysilylpropylpentadecafluorooctate, 3-triethoxysilylpropylpentadecafluorooctate, 3-trimethoxysilylpropylpentadecafluorooctate, 3- Trimethoxysilylpropylpentadecafluoroctiamide, 3-triethoxysilylpropylpentadecafluoroctiamide, 2-trimethoxysilylethylpentadecafluorodecylsulfide, 2-triethoxysilylethylpentadeca Pentafluorophenyltrimethoxysilane, pentafluorophenyltriethoxysilane, 4- (perfluorotolyl) trimethoxysilane, 4- (perfluorotolyl) triethoxysilane, pentafluorophenyltrimethoxysilane, (1) selected from the group consisting of dimethoxybis (pentafluorophenyl) silane, diethoxybis (4-pentafluorotolyl) silane, 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, More than two species of monomers are polymerized Can be used.

(d) Dispersant

The dispersant is contained in order to impart dispersion stability of the conductive metal powder in the photosensitive conductive paste composition. Examples thereof include oleic acid, polyethylene glycol fatty acid esters, glycerin esters, sorbitan esters, propylene glycol esters, At least one of fatty acid alkanolamide, polyoxyethylene fatty acid amide, polyoxyethylene alkylamine, amine oxide and poly 12-hydroxystearic acid can be used.

The content of the dispersant is preferably 0.1 to 3.0% by weight, more preferably 0.2 to 1.5% by weight based on the total weight of the photosensitive conductive paste composition. If the content of the dispersant is less than 0.1% by weight, the dispersion stability may be deteriorated. If the content of the dispersant is more than 3.0% by weight, dispersion stability may be deteriorated due to agglomeration of the metal powder.

(e) Photopolymerization Photoinitiator

The photopolymerization photoinitiator is a compound which generates a radical by generating radicals by irradiating light such as ultraviolet rays, and is a compound which generates benzophenone, methyl o-benzoylbenzoate, 4,4'-bis (dimethylamino) benzophenone, (Diethylamino) benzophenone, 4,4'-dichlorobenzophenone, 4-benzoyl-4'-methyldiphenyl ketone, dibenzyl ketone, fluorenone, 2,2'-diethoxyacetophenone, 2,2- Dimethoxy-2-phenylacetophenone, 2-hydroxy-2-methylpropiophenone, pt-butyldichloroacetophenone, thioxanthone, 2-methylthioxanthone, 2- chlorothioxanthone, Bis (p-azidobenzylidene) cyclohexanone, 6-bis (p-azidobenzylidene) -4-methyl Phenyl-1,2-butanedione-2- (o-methoxycarbonyl) oxime, 1-phenyl-propanedione 2- (o- ethoxycarbonyl) oxime, Propanedione-2- (o-benzoyl) oxime, 1,3-diphenyl-p- 2- (o-benzoyl) oxime, 1,2-octanedione, 1- [4- (2-oxo- (Phenylthio) -2- (O-benzoyloxime), 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide, bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide, Ketone, 2-methyl- [4- (methylthio) phenyl] -2-morpholino-1-propanone, naphthalenesulfonyl chloride, quinoline sulfonyl chloride, N-phenylthioacridone, Azobisisobutyronitrile, diphenyl disulfide, benzothiazole disulfide, triphenylphosphine, benzoin peroxide, and a light reducing pigment such as eosin and methylene blue, ascorbic acid, and triethanolamine Or more can be used.

The content of the photopolymerization photoinitiator is preferably 0.1 to 3% by weight based on the total weight of the photosensitive conductive paste composition. If the content of the photo-polymerizable photoinitiator is less than 0.1% by weight, the curing density of the exposed portion may decrease, and the cured film may be affected in the developing process. On the other hand, when the content of the photoinitiator exceeds 3% by weight, the light absorption at the upper portion of the coating film becomes excessive, which may cause problems in pattern formation.

(f) Solvent

The solvent is contained to adjust the viscosity of the photosensitive conductive paste composition and form a uniform coating film, and functions to dissolve or disperse the photosensitive binder and the photoinitiator. It is preferred that the solvent does not participate in the curing reaction and has a suitable boiling point to vaporize slowly at the drying temperature. In the case of using a solvent having a boiling point lower than the drying temperature, volatile voids are formed by the solvent during curing, which may result in poor workability. On the other hand, in the case of using a solvent having a high boiling point, Causing volume expansion, thereby causing cracks in the cured product, thereby lowering the reliability.

For example, the solvent may be at least one selected from the group consisting of N, N-dimethylacetamide, N, N-dimethylformamide, N-methylpyrrolidone, dimethylimidazolidinone, dimethylsulfoxide, At least one selected from the group consisting of methoxy-2-propanol, 1-ethoxy-2-propanol, ethylene glycol mono-n-propyl ether, diacetone alcohol, tetrahydrofurfuryl alcohol and propylene glycol monomethyl ether acetate Can be used.

The content of the solvent is preferably 1: 1) a solvent remaining in the binder obtained in the step of producing an acrylate-based photosensitive binder, and 2) a dosage of a solvent to be added as needed for controlling the viscosity of the photosensitive conductive paste composition comprising the binder . The content of such a solvent is preferably 5 to 15% by weight based on the total weight of the photosensitive conductive paste composition, and if the content of the solvent is less than 5% by weight, the milling workability may be deteriorated. On the other hand, The binder content is decreased and the adhesive strength may be rapidly lowered.

(g) Other additives

The photosensitive conductive paste composition of the present invention may further include other additives for improving properties such as conductivity, storage stability, and printability. Examples of such additives include plasticizers, coupling agents, antioxidants, curing accelerators, scattering inhibitors, thermal polymerization inhibitors, leveling agents, acid additives, defoamers and the like.

The content of the other additives is preferably 0.1 to 3.0% by weight based on the total weight of the photosensitive conductive paste composition, and when the content of the additive is less than 0.1% by weight, it may be difficult to exhibit a desired function, , A phenomenon of deterioration such as conductivity, printability and developability may be caused.

Hereinafter, the present invention will be described by way of examples, but the present invention is not limited to these examples.

Example 1

≪ Preparation of siloxane photosensitive crosslinking agent &

Vinyltrimethoxysilane, diphenylsilanediol, and dimethyldimethoxysilane were prepared as monomers for the production of the siloxane-based photosensitive crosslinking agent.

First, 50 g of acetone as a solvent was charged into a reaction vessel, 30 g of the vinyltrimethoxysilane, 100 g of diphenylsilanediol, 35 g of dimethyldimethoxysilane and 1 g of barium hydroxide monohydrate as a catalyst were added thereto, Followed by stirring. Subsequently, the temperature was raised to 60 占 폚, and a condensation reaction was carried out for 24 hours. Thereafter, 4 g of an adsorbent (KYOWAAD 700SL®) was added to remove the catalyst, the adsorbent was removed with a pressurizing filter, and the solvent was removed to prepare a siloxane photosensitive crosslinking agent.

≪ Preparation of acrylic binder &

130 g of Texanol was charged into the reaction vessel and the temperature was raised to 60 캜. A mixture of 30 g of methacrylic acid, 17 g of methyl methacrylate, 45 g of benzyl methacrylate and 3.7 g of 2,2'-azobisisobutyronitrile was added thereto, and polymerization was carried out for 6 hours. Subsequently, after the reaction temperature was raised to 70 占 폚, a mixture of 20 g of glycidyl methacrylate and 1 g of tetrabutylammonium chloride was added. After the addition, the addition reaction was carried out for 4 hours.

≪ Preparation of photosensitive organic composition >

The photosensitive organic composition was prepared by adding 4 g of the prepared siloxane photosensitive crosslinking agent vinylphenylmethylsiloxane to 13 g of the acrylate binder component, adding 0.54 g of oleic acid as a fatty acid-based dispersing agent and 0.54 g of an additive, Mix with a stirrer while pre-mixing. Then, 0.54 g of 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide as a photoinitiator was added thereto, and the mixture was stirred with a Thinky Mixer stirrer capable of revolution. The initiator was dissolved and homogeneously mixed to prepare a photosensitive organic composition.

≪ Preparation of Photosensitive Conductive Paste >

80 g of circular silver powder having an average particle diameter of 2.6 .mu.m was added to the photosensitive organic composition, and the mixture was pre-mixed using a Thinky Mixer stirrer, mixed and passed through a 3-roll mill several times to disperse uniformly. Thereafter, it was defoamed in a vacuum with a deaerator to prepare a photosensitive conductive paste. The viscosity was adjusted by adding a solvent if necessary.

≪ Pattern Formation of Photosensitive Conductive Paste &

The photosensitive conductive paste prepared above was printed and coated on a substrate using a plate of POLY 420 mesh by a screen printing method. Baked at 90 ° C for 10 minutes, cured by ultraviolet rays (UV) at 150 mJ / cm 2, developed by dissolving non-exposed areas with an aqueous solution of sodium carbonate (Na 2 CO 3) 0.5% To form a pattern. The development time is measured by measuring the dissolution time of the front printing portion after the electrothermal treatment process. After completion of the development and cleaning process, the conductive coating film was formed through a post-heat treatment process at 160 ° C for 30 minutes.

Examples 2 and 3, Comparative Examples 1 and 2

The procedure of Example 1 was repeated except that the contents of silver powder, an acrylate binder, a siloxane crosslinker, a trifunctional crosslinker, a dispersant, an additive, a photoinitiator and a solvent were controlled as shown in Table 1 below, . The content units of the ingredients listed in the following Table 1 are% by weight.

ingredient Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Silver powder ¹⁾ 80 80 80 80 80 Binder ²⁾ 11 9 7 11 13 Siloxane crosslinking agent ³⁾ 4 6 8 - 2 Trifunctional cross-linking agent ⁴⁾ - - - 4 - Dispersant ⁵⁾ 0.5 0.5 0.5 0.5 0.5 Additive ⁶⁾ 0.5 0.5 0.5 0.5 0.5 Photoinitiator ⁷⁾ 0.5 0.5 0.5 0.5 0.5 Solvent ⁸⁾ 3.5 3.5 3.5 3.5 3.5 Sum 100 100 100 100 100

1) silver powder (Ag Powder): 2.6 탆 average particle size spherical powder

2) Acrylate type binder (solid content 50%)

3) Siloxane crosslinking agent (solid content 80%)

4) Trifunctional crosslinking agent: Trimethylolpropane triacrylate (Sigma aldrich)

5) Dispersant: Oleic acid (Sigma aldrich)

6) Additives: leveling agent (BYK-354, BYK)

7) Photoinitiator: Phosphine oxide photoinitiator (BASF Japan.Ltd.)

8) Solvent: Tecanol (Sigma aldrich)

Resistivity, resolution and adhesion of the conductive coating films prepared according to Examples 1 to 3 and Comparative Examples 1 and 2 were evaluated by the following evaluation methods, and the results are shown in the following Table 2 and FIG.

Resistivity (Ω · cm):

The surface resistances of the conductive coatings prepared according to Examples 1 to 3 and Comparative Examples 1 and 2 were measured using a 4-point probe surface resistance meter (FPD-RS 8, DASOL ENG). The thickness of the patterned film was measured with an illuminometer (SURFCOM 130A, Tokyo Precision), and the resistivity value was calculated from the surface resistance and the film thickness.

Resolution (L / S, 탆):

The line-and-space (L / S) line width of the conductive coating film pattern was measured with an optical microscope (LS540IM, TESCO).

Adhesion:

The adhesion test of the electrode formed of the photosensitive conductive paste prepared according to Examples 1 to 3 and Comparative Examples 1 and 2 was carried out according to the method of ASTM D 3359 and the shape of the pattern electrode was measured with an optical microscope (LS540IM, TESCO) Respectively. This is shown in Fig.

Resistivity (Ω · cm) Resolution (L / S, 탆) Example 1 6.1 X 10 ^-5 20/20 Example 2 1.1 X 10 ^-4 20/20 Example 3 2.5 X 10 ^-4 20/20 Comparative Example 1 8.9 X 10 ^-5 20/20 Comparative Example 2 4.3 X 10 ^-5 20/20

As shown in Table 2, it was confirmed that the photosensitive conductive paste compositions of Examples 1 to 3 prepared according to the present invention had a low-resistance conductive coating film having a fine line width of 20 μm / 20 μm (L / S) have. However, the photosensitive conductive paste composition of Comparative Example 1 which did not include the siloxane crosslinking agent exhibited a relatively low specific resistance, but the adhesive strength was relatively low as compared with the case of containing the siloxane crosslinking agent. 2, the adhesion of the photosensitive conductive paste composition of Comparative Example 2 containing 2% by weight of the siloxane crosslinking agent is lowered.

Claims (7)

(a) 70 to 90% by weight of a conductive metal powder;
(b) 1 to 20% by weight of an acrylate-based photosensitive binder having an unsaturated double bond;
(c) 4 to 10 weight parts of a siloxane photosensitive crosslinking agent having a polyfunctional group containing a first repeating unit represented by the following formula (1), a second repeating unit represented by the following formula (2) and a third repeating unit represented by the following formula %;
(d) 0.1 to 3% by weight of a dispersant;
(e) 0.1 to 3% by weight of a photoinitiator; And
(f) an extra solvent.

[Chemical Formula 1]

(2)

(3)
(Wherein R1 is -CH = CH2 or -CH2CH2CH2OOCC (CH3) = CH2, R2 is -CH3 or -OCH3, and R3 is -OCH3 or -OCH2CH3. delete The photosensitive resin composition according to claim 1, wherein the siloxane photosensitive cross-
Wherein the first repeating unit is contained in an amount of 10 to 30 mol%, the second repeating unit is contained in an amount of 30 to 50 mol%, and the third repeating unit is contained in an amount of 20 to 60 mol% based on the total number of moles of the first to third repeating units %, Based on the total weight of the photosensitive conductive paste composition. 4. The photosensitive conductive paste composition according to claim 3, wherein the siloxane photosensitive crosslinking agent is represented by the following formula (4)

[Chemical Formula 4]
Wherein R 1 is -CH = CH 2 or -CH 2 CH 2 CH 2 OCC CH 3 = CH 2, R 2 is -CH 3 or -OCH 3, R 3 is -OCH 3 or -OCH 2 CH 3,
a is from 10 to 30, b is from 30 to 50, c is from 20 to 60, and a + b + c = 100. The method according to claim 1, wherein the conductive metal powder comprises at least one selected from the group consisting of silver (Ag), gold (Au), cobalt (Co), nickel (Ni), and copper (Cu) Conductive paste composition. The photosensitive conductive paste composition according to claim 1, wherein the conductive metal powder has at least one shape selected from the group consisting of spherical, angular, and plate shapes. The photosensitive conductive paste composition according to claim 1, wherein the conductive metal powder is a mixture of two or more metal powders having different average particle sizes (D50).

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