CN109071938B - Binder resin for conductive composition, conductive pattern-forming composition containing same, and polyurethane - Google Patents

Abstract

The invention provides a binder resin for a conductive composition for improving the conductivity of a conductive pattern with lower sintering energy, a composition for forming the conductive pattern containing the binder resin for the conductive composition, and polyurethane. The binder resin for conductive compositions comprises a polyurethane having a metal carboxylate moiety (M is a metal atom selected from metals belonging to group 11 of the periodic table, and n is the valence of the metal atom M) represented by (COO) nM in the polymer skeleton. The binder resin for conductive composition, the conductive material and a solvent for dissolving the binder resin for conductive composition are mixed to prepare a composition for forming conductive pattern, which improves conductivity with low sintering energy.

Description

Binder resin for conductive composition, conductive pattern-forming composition containing same, and polyurethane

Technical Field

The present invention relates to a binder resin for conductive compositions, a composition for forming conductive patterns containing the binder resin for conductive compositions, and polyurethane.

Background

As a technique for producing a fine wiring pattern, a method of forming a wiring pattern by photolithography using a copper foil and a photoresist in combination has been generally used, but this method also involves a large number of steps, and a large burden is imposed on drainage and waste liquid treatment, and an improvement in environmental aspects is desired. In addition, a method of patterning a metal thin film formed by a thermal evaporation method or a sputtering method by a photolithography method is also known. However, vacuum atmosphere is indispensable for the thermal vapor deposition method and the sputtering method, and the price is also extremely high, and it is difficult to reduce the manufacturing cost when applied to a wiring pattern.

Therefore, a technique of forming wiring by printing using an ink containing a metal or a metal oxide has been proposed. Since a large number of products can be manufactured at low cost and high speed by the printed wiring technique, the manufacture of some practical electronic devices has been studied.

For example, patent document 1 below discloses a method for manufacturing a substrate, which includes the steps of: the method for producing a conductive metal composite material includes a step of discharging a conductive inorganic composition containing conductive inorganic metal particles on a substrate, a step of discharging a conductive organic composition containing a conductive organic metal complex compound on the conductive inorganic composition, and a step of firing the conductive inorganic composition and the conductive organic composition.

However, in the method of heating and firing an ink containing a metal or the like using a heating furnace, it takes time in the heating step, and when the plastic substrate cannot withstand the heating temperature, there is a problem that satisfactory conductivity is not achieved.

Further, in patent document 1, there is also a problem that the conductive inorganic composition and the conductive organic composition need to be discharged separately, and the process is complicated.

Therefore, as described in patent documents 2 to 6, it is conceivable to use a conductive composition (ink) containing nanoparticles and convert the composition into metal wiring by light irradiation.

The method using light energy or microwaves for heating has a possibility that only the ink portion can be heated, and is a very good method.

However, in order to obtain a desired conductivity, light irradiation with high energy may be required, and in this case, similarly to firing in a heating furnace, the substrate may not be able to withstand the energy.

Documents of the prior art

Patent document

Patent document 1: japanese laid-open patent publication No. 2010-183082

Patent document 2: japanese Kokai publication 2008-522369

Patent document 3: booklet of WO2010/110969

Patent document 4: japanese Kokai publication No. 2010-528428

Patent document 5: booklet of WO2013/077447

Patent document 6: booklet of WO2015/064567

Disclosure of Invention

Problems to be solved by the invention

In general, as for the conductive pattern formed on the substrate, the higher the conductivity (the lower the volume resistivity) is desirable, but it can be said that the lower the sintering energy for achieving the same conductivity, the higher the performance of the conductive composition for forming the conductive pattern. Therefore, the conventional conductive composition is also desired to improve the conductivity at a further low sintering energy.

The purpose of the present invention is to provide a binder resin for a conductive composition, which can improve the conductivity of a conductive pattern with low sintering energy, a composition for forming a conductive pattern, which contains the binder resin for a conductive composition, and polyurethane.

Means for solving the problems

In order to achieve the above object, one embodiment of the present invention is a binder resin for a conductive composition, the binder resin comprising a polyurethane having a metal carboxylate moiety (M is a metal atom selected from metals belonging to group 11 of the periodic table, n is the valence number of the metal atom M) represented by (COO) nM in a polymer skeleton.

It is preferable that the polyurethane contains a urethane bond unit formed from (a1) a polyisocyanate compound and (a2) a dihydroxy compound having a carboxyl group as a structural unit.

It is preferable that the metal constituting the metal salt contains either silver or copper.

Further, it is preferable that the dihydroxy compound having a carboxyl group (a2) is at least one of 2, 2-dimethylolpropionic acid and 2, 2-dimethylolbutyric acid.

Further, it is preferable that the polyisocyanate compound (a1) is an alicyclic polyisocyanate, and it is more preferable that the alicyclic polyisocyanate is isophorone diisocyanate (IPDI) or bis- (4-isocyanatocyclohexyl) methane (hydrogenated MDI).

Another embodiment of the present invention is a conductive pattern forming composition including: the binder resin (a) for conductive composition, the conductive material (B), and the solvent (C) for dissolving the binder resin for conductive composition are preferable. As the conductive material (B), metal particles (B1), or metal nanowires and/or metal nanotubes (B2) may be used.

In the case where the metal particles (B1) are used as the conductive material (B), the ratio of the metal particles (B1) is preferably 20 to 95 mass%, the content of the solvent (C) dissolving the binder resin for conductive compositions is preferably 5 to 80 mass%, and the binder resin (a) for conductive compositions is preferably 1 to 15 parts by mass with respect to 100 parts by mass of the metal particles (B1), relative to the entire conductive pattern-forming composition.

In the case where the metal nanowire and/or the metal nanotube (B2) is used as the conductive material (B), the ratio of the metal nanowire and/or the metal nanotube (B2) is preferably 0.01 to 10 mass%, the content of the solvent (C) dissolving the binder resin for conductive compositions is 90 mass% or more, and the binder resin (a) for conductive compositions is preferably 10 to 400 parts by mass with respect to 100 parts by mass of the metal nanowire and/or the metal nanotube (B2), with respect to the entire conductive pattern forming composition.

It is preferable that the metal constituting the conductive material (B) contains any one of silver and copper.

Another embodiment of the present invention is a polyurethane containing at least one of the structural units represented by the following formula (1).

ADVANTAGEOUS EFFECTS OF INVENTION

According to the present invention, the conductivity of the conductive pattern can be improved with lower sintering energy than the case of using a binder resin containing no metal atom in the polymer skeleton.

Drawings

FIG. 1 is a graph showing the results of the differential thermal-thermogravimetry simultaneous measurement of a polyurethane silver salt (using silver nitrate) according to example 1.

FIG. 2 is a graph showing the results of the differential thermal-thermogravimetry of the polyurethane silver salt (using silver oxide) according to example 2.

FIG. 3 is a graph showing the measurement results of the Infrared (IR) absorption spectrum of the polyurethane synthesized in Synthesis example 1.

FIG. 4 is a graph showing the measurement results of the IR absorption spectrum of the silver polyurethane salt according to example 1.

Fig. 5 is a graph showing the results of measurement of Nuclear Magnetic Resonance (NMR) spectra of the polyurethane synthesized in synthesis example 1.

FIG. 6 is a graph showing the results of NMR spectroscopy on the polyurethane silver salt according to example 1.

FIG. 7 is a graph showing the results of the differential thermal-thermogravimetry of the copper salt of polyurethane (copper sulfate was used) according to example 3.

FIG. 8 is a graph showing the results of measuring the IR absorption spectrum of the copper salt of polyurethane according to example 3.

FIG. 9 is a graph showing the results of the differential thermal-thermogravimetry simultaneous measurement of the polyurethane silver salt (using silver nitrate) according to example 4.

FIG. 10 is a graph showing the results of the differential thermal-thermogravimetry of the silver urethane salt (using silver oxide) according to example 5.

FIG. 11 is a graph showing the results of the differential thermal-thermogravimetry simultaneous measurement of a polyurethane silver salt (using silver nitrate) according to example 6.

FIG. 12 is a graph showing the results of the differential thermal-thermogravimetry simultaneous measurement of a polyurethane silver salt (using silver nitrate) according to example 7.

FIG. 13 is a graph showing the results of a differential thermal-thermogravimetry simultaneous measurement of a polyurethane silver salt (using silver nitrate) according to example 8.

FIG. 14 is a graph showing the results of the differential thermal-thermogravimetry of the silver urethane salt (using silver oxide) according to example 9.

FIG. 15 is a graph showing the results of the differential thermal-thermogravimetry of the silver urethane salt (using silver oxide) according to example 10.

FIG. 16 is a graph showing the results of the differential thermal-thermogravimetry performed on the polyurethane silver salt (using silver oxide) according to example 11.

FIG. 17 is a graph showing the results of the differential thermal-thermogravimetry performed on the polyurethane silver salt (using silver oxide) according to example 12.

FIG. 18 is a graph showing the results of a differential thermal-thermogravimetry simultaneous with measurement of a polyurethane silver salt (using silver oxide) according to example 13.

FIG. 19 is a graph showing the results of a differential thermal-thermogravimetry simultaneous with measurement of a polyurethane silver salt (using silver oxide) according to example 14.

FIG. 20 is a graph showing the results of a simultaneous differential thermal-thermogravimetry of a copper salt of polyurethane (using copper hydroxide) according to example 16.

Detailed Description

Hereinafter, a mode for carrying out the present invention (hereinafter, referred to as an embodiment) will be described.

The binder resin for conductive compositions according to the present embodiment has the following features: comprising a polyurethane having a metal carboxylate moiety (M is a metal atom selected from metals belonging to group 11 of the periodic table, and n is the valence of the metal atom M) represented by (COO) nM in the polymer skeleton.

The polyurethane of the present embodiment comprises at least a polyisocyanate compound and a dihydroxy compound having a carboxyl groupThe urethane bond unit formed in the above-mentioned compound is used as a structural unit. Urethane bond units formed from a polyisocyanate compound and a polyol other than a dihydroxy compound having a carboxyl group may be contained. That is, a polyurethane resin obtained by mixing and reacting, if necessary, (a3) a polyol compound other than (a2) with (a1) a polyisocyanate compound and (a2) a dihydroxy compound having a carboxyl group may be used. Having a (COO) group in the polyurethane skeleton can be obtained by reacting a compound containing a metal atom M belonging to group 11 of the periodic table with a carboxyl group (COOH group) in the obtained polyurethane resin_nAnd a metal carboxylate moiety represented by M (n is the valence of the metal atom M).

Hereinafter, each constituent component used for producing the urethane resin included in the binder resin of the present embodiment will be described in more detail.

(a1) Polyisocyanate compound

As the (a1) polyisocyanate compound, a diisocyanate having 2 isocyanate groups per 1 molecule is generally used. Examples of the polyisocyanate compound include aliphatic polyisocyanates, alicyclic polyisocyanates, aromatic polyisocyanates, and araliphatic polyisocyanates. A polyisocyanate having 3 or more isocyanate groups such as triphenylmethane triisocyanate may be used in a small amount within a range in which gelation of the carboxyl group-containing polyurethane does not occur. The alicyclic polyisocyanate is preferable in that yellowing is small.

Examples of the aliphatic polyisocyanate include 1, 3-propane diisocyanate, 1, 4-butane diisocyanate, 1, 6-hexane diisocyanate, 1, 9-nonane diisocyanate, 1, 10-decane diisocyanate, 2, 4-trimethylhexamethylene diisocyanate, 2,4, 4-trimethylhexamethylene diisocyanate, lysine diisocyanate, 2' -diethyl ether diisocyanate, and dimer acid diisocyanate.

Examples of the alicyclic polyisocyanate include 1, 4-cyclohexane diisocyanate, 1, 3-bis (isocyanatomethyl) cyclohexane, 1, 4-bis (isocyanatomethyl) cyclohexane, isophorone diisocyanate (IPDI), bis- (4-isocyanatocyclohexyl) methane (hydrogenated MDI), hydrogenated (1, 3-or 1,4-) xylylene diisocyanate, norbornane diisocyanate and the like.

Examples of the aromatic polyisocyanate include 2,4 ' -diphenylmethane diisocyanate, 4 ' -diphenylmethane diisocyanate, 1, 4-phenylene diisocyanate, 2, 4-tolylene diisocyanate, 2, 6-tolylene diisocyanate, (1,2, 1,3, or 1,4) -xylene diisocyanate, 3 ' -dimethyl-4, 4 ' -diisocyanate biphenyl, 3 ' -dimethyl-4, 4 ' -diisocyanate diphenylmethane, 1, 5-naphthylene diisocyanate, 4 ' -diphenyl ether diisocyanate, tetrachlorophenylene diisocyanate, and the like.

Examples of the araliphatic polyisocyanate include 1, 3-xylylene diisocyanate, 1, 4-xylylene diisocyanate, α, α, α ', α' -tetramethylxylylene diisocyanate, and 3,3 '-methylenexylylene-4, 4' -diisocyanate.

These diisocyanates may be used singly in 1 kind or in combination in 2 or more kinds. Among them, isophorone diisocyanate (IPDI), bis- (4-isocyanatocyclohexyl) methane (hydrogenated MDI), and the like are preferable from the viewpoint of easy industrial availability.

(a2) Dihydroxy compound having carboxyl group

As the dihydroxy compound having a carboxyl group (a2), a carboxylic acid or an aminocarboxylic acid having 2 hydroxyl groups or hydroxyalkyl groups having 1 or 2 carbon atoms and a molecular weight of 200 or less is preferable in that the crosslinking point can be controlled. Specific examples thereof include 2, 2-dimethylolpropionic acid, 2-dimethylolbutyric acid, N-bishydroxyethylglycine, N-bishydroxyethylalanine and the like, and among these, 2-dimethylolpropionic acid and 2, 2-dimethylolbutyric acid are particularly preferable from the viewpoint of solubility in a solvent. These dihydroxy compounds having a carboxyl group (a2) may be used alone in 1 kind or in combination of 2 or more kinds.

(a3) Polyol compounds

The number average molecular weight of the polyol compound (a3) (however, the polyol compound (a3) does not contain the dihydroxy compound having a carboxyl group (a 2)) which may be used in combination as needed is usually 250 to 50,000, preferably 400 to 10,000, and more preferably 500 to 5,000. The molecular weight is a value in terms of polystyrene measured by GPC under the conditions described later. A number average molecular weight of 50,000 or less is preferable in that it is highly soluble in a solvent and also has an appropriate viscosity after dissolution, and thus is easy to use.

(a3) Examples of the polyol compound include polycarbonate polyols, polyether polyols, polyester polyols, polylactone polyols, polybutadiene polyols, both-terminal hydroxylated polyorganosiloxanes, and polyol compounds in which only hydroxyl groups contain oxygen atoms and the number of carbon atoms is 18 to 72.

The polycarbonate polyol can be obtained by reacting a diol having 3 to 18 carbon atoms as a raw material with a carbonate or phosgene, and is represented by, for example, the following structural formula (2).

In the formula (2), R¹Is derived from the corresponding diol (HO-R)¹-OH) residue after removal of hydroxyl groups, n₁Is a positive integer, preferably 2 to 50. If n is₁When the molecular weight is 50 or less, the deterioration of solubility due to the excessively large molecular weight can be suppressed.

Specifically, the polycarbonate polyol represented by the formula (2) can be produced by using 1, 3-propanediol, 1, 4-butanediol, 1, 5-pentanediol, 1, 6-hexanediol, 3-methyl-1, 5-pentanediol, 1, 8-octanediol, 1, 3-cyclohexanedimethanol, 1, 4-cyclohexanedimethanol, 1, 9-nonanediol, 2-methyl-1, 8-octanediol, 1, 10-decanediol, 1, 2-tetradecanediol, or the like as a raw material.

The polycarbonate polyol may be a polycarbonate polyol having a plurality of alkylene groups in the skeleton thereof (copolymerized polycarbonate polyol). The use of the copolymerized polycarbonate polyol is often advantageous from the viewpoint of preventing crystallization of the polyurethane having a carboxyl group. In addition, in consideration of solubility in a solvent, it is preferable to use a polycarbonate polyol having a branched skeleton and a hydroxyl group at the end of a branch in combination.

The polyether polyol is obtained by dehydrating and condensing a glycol having 2 to 12 carbon atoms, or ring-opening polymerization of an oxirane compound, oxetane compound or tetrahydrofuran compound having 2 to 12 carbon atoms, and is represented by, for example, the following structural formula (3).

In the formula (3), R²Is derived from the corresponding diol (HO-R)²-OH) residue after removal of hydroxyl groups, n₂Is a positive integer, preferably 4 to 50. The above-mentioned C2-12 diol may be used alone to prepare a homopolymer, or may be used in combination with 2 or more kinds to prepare a copolymer. If n is₂When the molecular weight is 50 or less, the deterioration of solubility due to the excessively large molecular weight can be suppressed.

Specific examples of the polyether polyol represented by the above formula (3) include polyalkylene glycols such as polyethylene glycol, polypropylene glycol, poly-1, 2-butanediol, polytetramethylene glycol (poly-1, 4-butanediol), poly-3-methyltetramethylene glycol, and poly-neopentyl glycol. In addition, copolymers thereof, for example, 1, 4-butanediol neopentyl glycol, may be used for the purpose of improving the compatibility of (polyether polyol) and the hydrophobicity of (polyether polyol).

The polyester polyol is obtained by subjecting a dicarboxylic acid and a diol to dehydration condensation or an ester exchange reaction between a lower alcohol of the dicarboxylic acid and the diol, and is represented by, for example, the following structural formula (4).

In the formula (4), R³Is derived from the corresponding diol (HO-R)³-OH) residue after removal of the hydroxyl group, R⁴Is from the corresponding twoCarboxylic acid (HOCO-R)⁴-COOH) 2 carboxyl groups removed, n₃Is a positive integer, preferably 2 to 50. If n is₃When the molecular weight is 50 or less, the deterioration of solubility due to the excessively large molecular weight can be suppressed.

As the above diol (HO-R)³Specific examples thereof include ethylene glycol, 1, 2-propanediol, 1, 3-propanediol, 1, 2-butanediol, 1, 3-butanediol, 1, 4-butanediol, 1, 5-pentanediol, 1, 6-hexanediol, 3-methyl-1, 5-pentanediol, 1, 8-octanediol, 1, 3-cyclohexanedimethanol, 1, 4-cyclohexanedimethanol, 1, 9-nonanediol, 2-methyl-1, 8-octanediol, 1, 10-decanediol or 1, 2-tetradecanediol, 2, 4-diethyl-1, 5-pentanediol, butylethylpropanediol, 1, 3-cyclohexanedimethanol, 3-benzenedimethanol, 1, 4-benzenedimethanol, 1, 3-benzenedimethanol, Diethylene glycol, triethylene glycol, dipropylene glycol, and the like.

As the above dicarboxylic acid (HOCO-R)⁴-COOH), specific examples thereof include succinic acid, glutaric acid, adipic acid, azelaic acid, sebacic acid, decanedicarboxylic acid, brassylic acid, 1, 4-cyclohexanedicarboxylic acid, hexahydrophthalic acid, methyltetrahydrophthalic acid, endomethylenetetrahydrophthalic acid, methylendomethylenetetrahydrophthalic acid, chlorendic acid, fumaric acid, maleic acid, itaconic acid, citraconic acid, phthalic acid, isophthalic acid, terephthalic acid, 1, 4-naphthalenedicarboxylic acid, and 2, 6-naphthalenedicarboxylic acid.

The polylactone polyol is obtained by a condensation reaction between a ring-opened lactone polymer and a diol, or a condensation reaction between a diol and a hydroxyalkanoic acid, and is represented by, for example, the following structural formula (5).

In the formula (5), R⁵From the corresponding hydroxy alkanoic acid (HO-R)⁵-COOH) residue after removal of hydroxyl and carboxyl groups, R⁶Is derived from the corresponding diol (HO-R)⁶-OH) residue after removal of hydroxyl groups, n₄Is a positive integer, preferably 2 to 50. If n is₄When the molecular weight is 50 or less, the molecular weight can be suppressed from becoming too largeThe deterioration of solubility of (c).

As the above-mentioned hydroxyalkanoic acid (HO-R)⁵-COOH), specific examples thereof include 3-hydroxybutyric acid, 4-hydroxyvaleric acid, 5-hydroxyhexanoic acid and the like.

The polybutadiene polyol is, for example, a diol obtained by polymerizing butadiene and isoprene by anionic polymerization and introducing hydroxyl groups at both ends by terminal treatment, and a diol obtained by hydrogen-reducing the double bond of these diols.

Specific examples of the polybutadiene polyol include hydroxylated polybutadienes having mainly 1, 4-repeating units (e.g., Polybd R-45HT, Polybd R-15HT (manufactured by Shiko corporation)), hydroxylated hydrogenated polybutadienes (e.g., ポリテール (registered trademark) H, ポリテール (registered trademark) HA (manufactured by Mitsubishi chemical corporation)), hydroxylated hydrogenated polybutadienes having mainly 1, 2-repeating units (e.g., G-1000, G-2000, G-3000 (manufactured by Nippon Kao corporation)), hydroxylated hydrogenated polybutadienes (e.g., GI-1000, GI-2000, GI-3000 (manufactured by Nippon Kao corporation)), hydroxylated polyisoprenes (e.g., Poly IP (manufactured by Kao corporation))), and hydroxylated polyisoprenes (e.g., PolyIP (manufactured by Kao corporation))), Hydroxylated hydrogenated polyisoprene (for example, エポール (registered trademark, manufactured by Kyoto Co., Ltd.)).

The both-terminal-hydroxylated polyorganosiloxane is represented by, for example, the following structural formula (6).

In the formula (6), R⁷Independently a divalent residue of an aliphatic hydrocarbon or a divalent residue of an aromatic hydrocarbon having 2 to 50 carbon atoms, n₅Is a positive integer, preferably 2 to 50. They may contain ether groups, a plurality of R⁸Each independently is an aliphatic or aromatic hydrocarbon group having 1 to 12 carbon atoms. If n is₅When the molecular weight is 50 or less, the deterioration of solubility due to the excessively large molecular weight can be suppressed.

Examples of commercially available products of the above-mentioned both-terminal-hydroxylated polyorganosiloxanes include "X-22-160 AS", KF6001, KF6002 and KF-6003 ", manufactured by shin-Etsu chemical Co., Ltd. The "polyol compound having 18 to 72 carbon atoms and only hydroxyl groups containing oxygen atoms" includes, specifically, a diol compound having a skeleton obtained by hydrogenating a dimer acid, and its commercially available product includes, for example, "SOVERMOL (registered trademark) 908" manufactured by コグニス.

In addition, a diol having a molecular weight of 300 or less, which does not have a repeating unit, may be used as the (a3) polyol compound within a range not impairing the effects of the present invention. Specific examples of such low molecular weight diols include ethylene glycol, 1, 2-propanediol, 1, 3-propanediol, 1, 2-butanediol, 1, 3-butanediol, 1, 4-butanediol, 1, 5-pentanediol, 1, 6-hexanediol, 3-methyl-1, 5-pentanediol, 1, 8-octanediol, 1, 3-cyclohexanedimethanol, 1, 4-cyclohexanedimethanol, 1, 9-nonanediol, 2-methyl-1, 8-octanediol, 1, 10-decanediol, 1, 2-tetradecanediol, 2, 4-diethyl-1, 5-pentanediol, butylethylpropanediol, 1, 3-cyclohexanedimethanol, 1, 3-benzenedimethanol, 1, 4-benzenedimethanol, 1, 3-benzenedimethanol, Diethylene glycol, triethylene glycol, dipropylene glycol, or the like.

The polyurethane having a carboxyl group can be synthesized from only the above-mentioned components (a1), (a2) or only (a1), (a2) and (a3), but can be synthesized by further reacting (a4) a monohydroxy compound and/or (a5) a monoisocyanate compound for the purpose of further imparting radical polymerizability and cationic polymerizability to the polyurethane or for the purpose of suppressing the influence of the isocyanate group or the residue of a hydroxyl group at the terminal of the polyurethane.

(a4) Monohydroxy compound

Examples of the monohydroxy compound (a4) include compounds having a radical polymerizable double bond such as 2-hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, hydroxybutyl (meth) acrylate, cyclohexanedimethanol mono (meth) acrylate, caprolactone or alkylene oxide adducts of the above-mentioned (meth) acrylates, glycerol di (meth) acrylate, trimethylol di (meth) acrylate, pentaerythritol tri (meth) acrylate, dipentaerythritol penta (meth) acrylate, ditrimethylolpropane tri (meth) acrylate, allyl alcohol, and allyloxyethanol, and compounds having a carboxylic acid such as glycolic acid and hydroxypivalic acid.

(a4) The monohydroxy compound may be used alone in 1 kind or in combination of 2 or more kinds. Among these compounds, 2-hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, hydroxybutyl (meth) acrylate, allyl alcohol, glycolic acid, and hydroxypivalic acid are preferable, and 2-hydroxyethyl (meth) acrylate and 4-hydroxybutyl (meth) acrylate are more preferable.

Examples of the monohydroxy compound (a4) include methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, sec-butanol, tert-butanol, pentanol, hexanol, and octanol.

(a5) Monoisocyanate compound

Examples of the monoisocyanate compound (a5) include compounds having a radical carbon-carbon double bond such as (meth) acryloyloxyethyl isocyanate and monoadducts of the following compounds to diisocyanate compounds: 2-hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, hydroxybutyl (meth) acrylate, cyclohexanedimethanol mono (meth) acrylate, caprolactone or alkylene oxide adducts of the above-mentioned (meth) acrylates, glycerol di (meth) acrylate, trimethylol di (meth) acrylate, pentaerythritol tri (meth) acrylate, dipentaerythritol penta (meth) acrylate, ditrimethylolpropane tri (meth) acrylate, allyl alcohol, allyloxyethanol.

Further, the monoisocyanate hydroxyl compound used for the purpose of suppressing the influence of the terminal hydroxyl residue includes phenyl isocyanate, hexyl isocyanate, dodecyl isocyanate and the like.

The polyurethane having a carboxyl group can be synthesized by reacting the above-mentioned polyisocyanate compound (a1), (a2) dihydroxy compound having a carboxyl group, (a3) polyol compound, and if necessary, (a4) monohydroxy compound, and (a5) monoisocyanate compound, using an appropriate organic solvent in the presence or absence of a known urethanization catalyst such as dibutyltin dilaurate.

The organic solvent is not particularly limited as long as it is an organic solvent having low reactivity with an isocyanate compound, and when the polyurethane obtained after the reaction is used as it is in a solution state as a raw material of the composition for forming a conductive pattern (conductive ink), a solvent having a boiling point of 110 ℃ or higher, preferably 150 ℃ or higher, and more preferably 200 ℃ or higher is preferable. If the boiling point is 110 ℃ or higher, volatilization of the solvent in ink production can be suppressed. Examples of such solvents include toluene, xylene, ethylbenzene, nitrobenzene, isophorone, diethylene glycol dimethyl ether, ethylene glycol diethyl ether, ethylene glycol monomethyl ether monoacetate, propylene glycol monoethyl ether monoacetate, dipropylene glycol monomethyl ether monoacetate, diethylene glycol monoethyl ether monoacetate, methyl methoxypropionate, ethyl methoxypropionate, methyl ethoxypropionate, ethyl ethoxypropionate, N-butyl acetate, isoamyl acetate, ethyl lactate, cyclohexanone, N-dimethylformamide, N-dimethylacetamide, N-methylpyrrolidone, γ -butyrolactone, and dimethylsulfoxide.

In addition, when considering that an organic solvent having low solubility of the resulting polyurethane is not preferable and that the polyurethane is used as a raw material of ink in electronic material applications, propylene glycol monomethyl ether monoacetate, propylene glycol monoethyl ether monoacetate, dipropylene glycol monomethyl ether monoacetate, diethylene glycol monoethyl ether monoacetate, diethylene glycol monobutyl ether monoacetate, γ -butyrolactone, and the like are particularly preferable among them.

In addition, when the obtained polyurethane is used as a raw material of a conductive ink after solvent substitution, it is preferable to use a solvent having a boiling point lower than 110 ℃. Examples of such a solvent include cyclohexane, ethyl acetate, acetone, methyl ethyl ketone, chloroform, and methylene chloride. In addition, in the case of using the above-mentioned solvent having a boiling point of 110 ℃ or higher, there is no problem in carrying out the solvent substitution.

The order of adding the raw materials is not particularly limited, but usually, (a2) a dihydroxy compound having a carboxyl group and (a3) a polyol compound are added first, dissolved in a solvent, and then (a1) a polyisocyanate compound is added dropwise at 20 to 150 ℃, more preferably 50 to 120 ℃, and then they are reacted at 30 to 160 ℃, more preferably 50 to 130 ℃. The dihydroxy compound having a carboxyl group (a2) is easily dissolved when the temperature at the time of dropping is 20 ℃ or higher, and runaway caused by rapid progress of the reaction at the time of dropping can be prevented when the temperature is 150 ℃ or lower. Further, if the temperature during the reaction is 30 ℃ or higher, the polymerization reaction proceeds rapidly, and if it is 160 ℃ or lower, the coloration of the polyurethane can be suppressed. In addition, in the case where the (a3) polyol compound is not used, only the (a2) dihydroxy compound having a carboxyl group is added first.

The molar ratio of the raw materials added is adjusted depending on the molecular weight and acid value of the target polyurethane resin, but when the (a4) monohydroxy compound is introduced into the polyurethane resin, in order to make the terminal of the polyurethane molecule an isocyanate group, it is necessary to use the (a1) polyisocyanate compound in excess of the (a2) dihydroxy compound having a carboxyl group and the (a3) polyol compound (so that the isocyanate group becomes excess of the total of hydroxyl groups).

Specifically, regarding their addition molar ratio, (a1) isocyanate group of polyisocyanate compound: (the hydroxyl group of the (a2) dihydroxy compound having a carboxyl group + (the hydroxyl group of the a3) polyol compound) is 0.5 to 1.5: 1, preferably 0.8-1.2: 1, more preferably 0.95 to 1.05. When the molar ratio of the isocyanate groups in the polyisocyanate compound (a1) is 0.5 or more and 1.5 or less, it becomes easy to obtain a polyurethane having a high molecular weight.

Further, the ratio of (a2) the hydroxyl group of the dihydroxy compound having a carboxyl group to ((a2) the hydroxyl group of the dihydroxy compound having a carboxyl group + (a3) the hydroxyl group of the polyol compound) was 1: 0.05-1, preferably 1: 0.35 to 1, more preferably 1: 0.45 to 1. If the ratio of the hydroxyl group in the dihydroxy compound having a carboxyl group (a2) is 0.05 or more, the metal salt portion can be introduced into the polyurethane in an amount necessary for improving the conductivity.

When the (a4) monohydroxy compound is used, it is preferable that the molar amount of the (a1) polyisocyanate compound is more than the molar amount of the ((a2) carboxyl group-containing dihydroxy compound + (a3) polyol compound), and the molar amount of the (a4) monohydroxy compound is used in an amount of 0.5 to 1.5 times, preferably 0.8 to 1.2 times, the molar amount of the excess molar amount of the isocyanate group. When the molar amount of the monohydroxy compound (a4) is 0.5 times or more the molar amount, the isocyanate groups at the terminal of the polyurethane can be reduced, and when the molar amount is 1.5 times or less the unreacted monohydroxy compound can be prevented from remaining and adversely affecting the subsequent steps.

In order to introduce the (a4) monohydroxy compound into the polyurethane having a carboxyl group, at a time when the reaction of the (a2) dihydroxy compound having a carboxyl group and the (a3) polyol compound with the (a1) polyisocyanate compound is substantially completed, (a4) monohydroxy compound is added dropwise to the reaction solution at 20 to 150 ℃, more preferably 70 to 120 ℃, and then the reaction is maintained at that temperature to complete the reaction, so that the isocyanate groups remaining at both ends of the polyurethane having a carboxyl group are reacted with the (a4) monohydroxy compound. When the dropping and reaction temperature is 20 ℃ or higher, the reaction between the remaining isocyanate group and the monohydroxy group (a4) proceeds rapidly, and when the temperature is 150 ℃ or lower, the reaction is prevented from proceeding rapidly and running away at the time of dropping.

When the (a5) monoisocyanate compound is used, the molar amount of the (a2) dihydroxy compound having a carboxyl group + (a3) polyol compound is in excess of the molar amount of the (a1) polyisocyanate compound, and the molar amount of the excess molar amount with respect to the hydroxyl group is 0.5 to 1.5 times, preferably 0.8 to 1.2 times. When the molar amount of the monoisocyanate compound (a5) is 0.5 times or more, the hydroxyl group can be prevented from remaining at the terminal of the polyurethane, and when the molar amount is 1.5 times or less, the monoisocyanate compound can be prevented from remaining and adversely affecting the subsequent steps.

In order to introduce the (a5) monoisocyanate compound into the polyurethane having a carboxyl group, at the time when the reaction of the (a2) dihydroxy compound having a carboxyl group and the (a3) polyol compound with the (a1) polyisocyanate compound is substantially completed, the (a5) monoisocyanate compound is added dropwise to the reaction solution at 20 to 150 ℃, more preferably 50 to 120 ℃ and then held at that temperature to complete the reaction, in order to react the hydroxyl groups remaining at both ends of the polyurethane having a carboxyl group with the (a5) monoisocyanate compound. When the dropping and reaction temperature is 20 ℃ or higher, the reaction between the remaining hydroxyl group and the (a5) monoisocyanate compound proceeds rapidly, and when the temperature is 150 ℃ or lower, the reaction is prevented from proceeding rapidly and running away at the time of dropping.

The number average molecular weight of the polyurethane having a carboxyl group is preferably 1,000 to 100,000, and more preferably 3,000 to 50,000. Here, the molecular weight is a value in terms of polystyrene measured by gel permeation chromatography (hereinafter, referred to as GPC). When the number average molecular weight is 1,000 or more, adhesion between the finally formed conductive pattern and the substrate is exhibited, and when the number average molecular weight is 100,000 or less, deterioration of solubility in a solvent due to an excessively large molecular weight and an excessively high viscosity after dissolution can be suppressed.

In the present specification, GPC measurement conditions are as described in the examples described below.

The acid value of the polyurethane having a carboxyl group is preferably 5 to 160mgKOH/g, and more preferably 10 to 150 mgKOH/g. When the acid value is 5mgKOH/g or more, a metal salt portion in an amount necessary for improving the conductivity can be introduced into the polyurethane. In addition, if 160mgKOH/g or less, the solubility in the solvent is good, and the kind of solvent that can be used is also large.

In the present specification, the acid value of the resin is a value measured by a method described in examples described later.

Further, the metal atom M forming a salt with all or a part of the carboxyl groups of the polyurethane having carboxyl groups is a metal belonging to group 11 of the periodic table. The metal atom M is preferably silver or copper in terms of small volume resistivity.

The metal salts of the polyurethanes can be synthesized by any method. For example, the carboxyl group in the polyurethane is neutralized with a base, and then reacted with a metal salt of an inorganic acid such as nitric acid, sulfuric acid, or carbonic acid. Alternatively, the carboxyl group may be directly reacted with a basic oxide or hydroxide of a metal such as silver oxide, silver hydroxide, copper oxide, cuprous oxide, or copper hydroxide. In the case of directly reacting a carboxyl group with a basic oxide or hydroxide of a metal, a powder of the basic oxide or hydroxide may be directly added to the polyurethane solution, or the powder may be dispersed in a solvent in advance and then added to the polyurethane solution. In the case where the reaction is stopped by the adhesion of the powder to the bottom of the container or the like in the reaction, the latter method is adopted, whereby the powder is less likely to be agglomerated and the adhesion can be prevented. Further, the reaction may be carried out by heating as necessary. The reaction temperature is 20 ℃ to 150 ℃, more preferably 20 ℃ to 120 ℃. If the temperature is 20 ℃ or higher, the reaction proceeds rapidly, and even if the solid content concentration of the metal salt obtained as a solution becomes high, the fluidity increases, so that the reaction can be accelerated. Therefore, the degree of freedom in composition of the ink (conductive pattern forming composition) can be improved. Further, in the case of 150 ℃ or lower, thermal decomposition of polyurethane due to overheating can be prevented. The following methods are particularly exemplified as a method for synthesizing a metal salt of polyurethane.

< Synthesis of silver salt >

(1) A method in which carboxyl groups in polyurethane are neutralized with sodium hydroxide to prepare sodium salts, and then the sodium salts are reacted with silver nitrate to bind the carboxyl groups to silver.

(2) And a method of reacting the carboxyl group in the polyurethane with silver oxide to bond the carboxyl group to silver.

< Synthesis of copper salt >

(1) The carboxyl group in the polyurethane is neutralized with sodium hydroxide to prepare a sodium salt, and then the sodium salt is reacted with copper sulfate to bond the carboxyl group to copper.

(2) A method of reacting carboxyl groups in polyurethane with copper hydroxide to bond carboxyl groups to copper.

The proportion of the metal salt formed in the carboxyl group of the polyurethane is not generally determined because it is influenced by the chemical structure, molecular weight and acid value of the original polyurethane, but is preferably 5 to 100 mol%, more preferably 35 to 100 mol%. When the ratio of the metal salt to be formed is 5 mol% or more, the effect of improving the conductivity can be exhibited.

The composition for forming a conductive pattern according to an embodiment includes the binder resin (a) for a conductive composition, a conductive material (B), and a solvent (C) in which the binder resin for a conductive composition is dissolved.

The conductive material (B) that can be used is not particularly limited as long as it has conductivity. It is preferable to mainly use at least 1 of metal particles (including metal nanoparticles), metal nanowires, and metal nanotubes. The metal nanowire and/or the metal nanotube are fine linear metals having a diameter of nanometer order, the metal nanowire is a conductive material having a linear shape, and the metal nanotube is a conductive material having a porous or non-porous tubular shape. In the present specification, "linear" and "tubular" are both linear, but the former means a shape in which the central portion is not hollow (hollow) in the longitudinal direction, and the latter means a shape in which the central portion is hollow (hollow) in the longitudinal direction. The shape may be soft or rigid. The metal nanowire or the metal nanotube may be used alone, or a mixture of both may be used. The metal constituting the conductive material may be the same metal as or different from the metal forming the metal salt in the binder resin for a conductive composition. The kind of metal is appropriately selected depending on the conductivity, corrosion resistance and other physical properties required for the composition for forming a conductive pattern (conductive ink). Examples thereof include silver, copper, nickel, gold, platinum, palladium, and aluminum. In particular, silver or copper is preferably used from the viewpoint of the level of conductivity.

The shape of the metal particles is not particularly limited, but if flat particles are used, the area where the particles are in contact with each other is increased, which is preferable in that the resistance is easily lowered. If the aspect ratio of the flat metal particles (width/thickness of the flat metal particles) is large, the contact area between the metal particles becomes large, which is advantageous in terms of conductivity, but if it is too large, printing accuracy is lowered (printing of a fine pattern is difficult), and dispersibility is also lowered. Therefore, the width/thickness ratio is preferably in the range of 3 to 200, more preferably in the range of 5 to 100. The shape of the flat metal particles is measured by 10-point SEM observation with the observation position changed at a magnification of 1 ten thousand times, and the thickness and width of the flat metal particles are measured, and the thickness is determined as the number average value thereof, and the thickness is preferably 5nm to 2 μm, and more preferably in the range of 20nm to 1 μm.

The average particle diameter of the metal particles of other shapes including flat metal particles (in the case of spherical particles, the average particle diameter thereof) close to the sphere can be, for example, an average particle diameter in the range of 0.01 to 100 μm, preferably in the range of 0.02 to 50 μm, and more preferably in the range of 0.04 to 10 μm. The average particle diameter here is a median particle diameter (D) measured by a laser diffraction method₅₀) For example, SALD-3100 (manufactured by Shimadzu corporation) and LA-950V2 (manufactured by horiba corporation) can be used for the measurement.

The average thickness of the diameters of the metal nanowires and the metal nanotubes is preferably small from the viewpoint of conductivity, but is preferably large from the viewpoint of strength and ease of handling. Therefore, the average value of the wire diameter is preferably 500nm or less, more preferably 200nm or less, further preferably 100nm or less, and particularly preferably 80nm or less from the viewpoint of conductivity. On the other hand, from the viewpoint of strength and ease of handling, it is preferably 1nm or more, more preferably 5nm or more, and still more preferably 10nm or more.

The average length of the major axis of the metal nanowire or the metal nanotube is preferably long from the viewpoint of conductivity, but the length needs to be limited to some extent if a fine pattern is to be formed. Therefore, the average value of the line length is preferably 1 μm or more, more preferably 2 μm or more, and further preferably 5 μm or more from the viewpoint of conductivity. On the other hand, from the viewpoint of coping with fine patterns, it is preferably 100 μm or less, more preferably 50 μm or less, and still more preferably 30 μm or less.

The average of the thicknesses of the diameters and the average of the lengths of the long axes of the metal nanowires and the metal nanotubes satisfy the above ranges, and the average of the aspect ratios is preferably more than 5, more preferably 10 or more, further preferably 100 or more, and particularly preferably 200 or more. Here, the aspect ratio is a value obtained from a/b when the average thickness of the diameters of the metal nanowire and the metal nanotube is approximated to b and the average length of the major axis is approximated to a. The values of a and b can be determined as an average value by measuring 20 arbitrary roots using a scanning electron microscope.

In addition to the metal particles, metal nanowires, and metal nanotubes, metal oxides and carbon-based materials may be used. The metal constituting the metal oxide particles may be the same metal as or different from the metal forming the metal salt in the binder resin for the conductive composition. The metal species is appropriately selected according to the conductivity, corrosion resistance and other properties required for the composition for forming a conductive pattern. Examples of the metal oxide include Indium Tin Oxide (ITO), zinc oxide, tin oxide, and indium oxide. Examples of the carbon-based material include carbon black, graphite, and carbon nanotubes.

The shape of the metal oxide particles is not particularly limited, and flat particles are preferably used as in the case of the metal particles. The preferred average particle diameter is equivalent to that of the metal particles.

The solvent (C) is a solvent capable of dissolving the polyurethane having a carboxyl group used for the binder resin for the conductive composition, and may be used as long as an appropriate viscosity can be imparted when the composition for forming a conductive pattern is used as an ink. Specific examples thereof include ethyl carbitol acetate, ethyl carbitol, butyl carbitol acetate, butyl carbitol, terpineol, dihydroterpineol, isobornyl cyclohexanol and the like.

The ratio of the binder resin (a) for conductive compositions, the ratio of the conductive material (B), and the ratio of the solvent (C) in the composition for forming conductive patterns are different from the case of using metal nanowires and/or metal nanotubes (B2) in the case of using the metal particles (B1). In the case of the metal particles (B1), the expression of conductivity is a contact between the metal particles at points or surfaces, whereas in the case of the metal nanowires and/or the metal nanotubes (B2), the metal nanowires and/or the metal nanotubes (B2) are used because the metal nanowires and/or the metal nanotubes are in contact (connection) only at intersecting (overlapping) portions, and therefore the ratio of the metal nanowires and/or the metal nanotubes (B2) to the entire composition is smaller than that in the case of the metal particles (B1). Further, regarding the ratio of the binder resin (a) and the ratio of the solvent (C), the case of using the metal nanowire and/or the metal nanotube (B2) becomes relatively larger than the case of using the metal particle (B1).

When the metal particles (B1) are used as the conductive material (B), the proportion of the binder resin (a) for conductive compositions is 1 to 15 parts by mass, preferably 2 to 10 parts by mass, and more preferably 2.5 to 5 parts by mass, based on 100 parts by mass of the metal particles (B1) in the composition. When the ratio is 1 part by mass or more, the adhesion between the conductive pattern and the base material is expressed while maintaining the dispersibility of the conductive material. Further, if the proportion is 15 parts by mass or less, deterioration of conductivity due to an excessive increase in the polymer component contained in the finally formed conductive pattern can be suppressed.

The proportion of the metal particles (B1) is 20 to 95 mass%, preferably 30 to 92 mass%, and more preferably 45 to 90 mass% with respect to the entire composition. If the ratio of the metal particles is 20 mass% or more, the conductivity of the finally formed conductive pattern can be obtained. Further, if the proportion of the metal particles is 95 mass% or less, the viscosity of the composition for forming a conductive pattern does not become too high, and problems such as blooming and the like occur when a conductive pattern is formed by printing or coating.

When the metal particles (B1) are used as the conductive material (B), the proportion of the solvent (C) is 5 to 80 mass%, preferably 10 to 70 mass%, and more preferably 15 to 60 mass% with respect to the entire composition. If the content is 5% by mass or more, the binder resin (A) for the conductive composition can be sufficiently dissolved. Further, if the content is 80% by mass or less, the viscosity of the composition for forming a conductive pattern, which can be pattern-printed, may be set.

The proportion of the binder resin (a) for conductive compositions in the case of using metal nanowires and/or metal nanotubes (B2) as the conductive material (B) is 10 to 400 parts by mass, preferably 50 to 300 parts by mass, and more preferably 100 to 250 parts by mass, based on 100 parts by mass of the metal nanowires and/or metal nanotubes (B2) in the composition. When the amount is 10 parts by mass or more, the effect of reducing the electric resistance derived from the metal salt site can be expected. Further, if the proportion is 400 parts by mass or less, deterioration of conductivity due to an excessive increase in the polymer component contained in the finally formed conductive pattern can be suppressed.

The ratio of the metal nanowires and/or metal nanotubes (B2) is 0.01 to 10% by mass, preferably 0.02 to 5% by mass, and more preferably 0.05 to 2% by mass, based on the entire composition. If the metal nanowires and/or metal nanotubes are 0.01 mass% or more, it is not necessary to print the transparent conductive film layer thick to ensure desired conductivity, and printing is easy. Further, if the content is 10 mass% or less, it is not necessary to print the transparent conductive film layer thinly in order to secure desired optical characteristics, and printing is also easy in this case.

When the metal nanowire and/or the metal nanotube (B2) is used as the conductive material (B), the proportion of the solvent (C) is 90 mass% or more, and more preferably 98 mass% or more, based on the entire composition. When the ratio is 90% by mass or more, deterioration of conductivity due to excessive increase of the polymer component and deterioration of optical characteristics due to excessive increase of the conductive component in the finally formed conductive pattern can be suppressed.

In addition, as the binder resin, a resin other than polyurethane having a metal carboxylate moiety represented by (COO) nM (M is a metal atom selected from metals belonging to group 11 of the periodic table, and n is the valence number of the metal atom M) in the polymer skeleton may be used in combination within a range not impairing the effect of the present invention. When used in combination, the proportion of the polyurethane is preferably 50% by mass or more, more preferably 70% by mass or more, and still more preferably 90% by mass or more, based on the entire binder resin. If the proportion of the polyurethane to the entire binder resin is 50% by mass or more, the high molecular weight component which does not have the effect of lowering the resistance in the finally formed conductive pattern can be prevented from becoming excessive and the conductivity is prevented from being increased. Examples of the binder resin that can be used in combination include poly-N-vinylpyrrolidone, poly-N-vinylacetamide, poly-N-vinyl compounds such as poly-N-vinylcaprolactam, polyalkylene glycols such as polyethylene glycol, polypropylene glycol and poly-THF, cellulose and its derivatives, epoxy resins, polyesters, chlorinated polyolefins, thermoplastic resins such as polyacrylic resins, and thermosetting resins.

In the composition for forming a conductive pattern according to the embodiment, other additives may be used as needed within a range that does not impair the characteristics of the composition for forming a conductive pattern. The additive that can be used in combination may include additives such as a surfactant, an antioxidant, a filler, a thixotropy-imparting agent, a leveling agent, and an ultraviolet absorber. Fillers such as fumed silica can be used to adjust the viscosity of the composition. The amount of these components (ratio to the whole composition) is preferably 5% by mass or less in total.

The composition for forming a conductive pattern according to an embodiment can be produced by blending the binder resin (a) for a conductive composition, the conductive material (B), and the solvent (C) for dissolving the binder resin for a conductive composition described above, and additives that may be added as needed in the above blending ratio (mass%) so that the total amount of the binder resin (a) for a conductive composition, the conductive material (B), and the solvent (C) for dissolving the binder resin for a conductive composition becomes 100 mass% or less. The blending method is not particularly limited, and the blend may be produced by mixing with a rotation and revolution mixer, a homogenizer, a three-roll mixer, a high shear mixer, a propeller mixer, a mixer (mix roller), or the like.

When the composition for forming a conductive pattern (conductive ink) according to the embodiment is used, the conductivity of the conductive pattern can be improved with low sintering energy. In the present specification, the conductive pattern refers to a pattern formed by printing a conductive pattern-forming composition on a base material in a predetermined pattern and applying energy as necessary to sinter the conductive material. The pattern is not necessarily a thin line, and a so-called full pattern such as a square having a certain area is also included in the pattern.

The shape of the substrate on which the composition for forming a conductive pattern according to the present embodiment is applied and printed is not particularly limited as long as it is an insulating substrate. From the viewpoint of ease of coating and printing, the shape is preferably a plate, sheet or film. Examples thereof include ceramics such as glass and alumina, thermoplastic resins such as polyester resins, cellulose resins, vinyl alcohol resins, vinyl chloride resins, cycloolefin resins, polycarbonate resins, acrylic resins, ABS resins, and polyimide resins, photocurable resins, and thermosetting resins. Further, these base material surfaces may be subjected to an activation treatment using a treatment for further improving adhesion. Among the above-mentioned base materials, glass, polyester resin, cellulose resin, vinyl alcohol resin, acrylic resin, polyimide resin, and the like having a functional group (hydroxyl group, carbonyl group, amino group, and the like) having an interaction (hydrogen bond, and the like) with a urethane bond in the binder resin are preferable.

The printing method of the conductive pattern is not particularly limited as long as it is a known method, and spray coating, bar coating, roll coating, die coating, inkjet coating, screen coating, dip coating, relief printing, gravure printing, or the like can be used. The coating method and the conditions of the material may include a process of heating the substrate after wet coating to remove the coated material and the solvent used, a process of washing off the solvent and the like by washing, and the like.

Examples

Hereinafter, examples of the present invention will be specifically described. In addition, the following examples are examples for facilitating understanding of the present invention, and the present invention is not limited to these examples.

< method for measuring physical Property value >

(GPC)

The weight average molecular weight is a value in terms of polystyrene measured by GPC, and the measurement conditions are as follows.

Shodex GPC-101 as a measuring apparatus

Column Shodex column LF-804

Mobile phase Tetrahydrofuran (THF)

Flow rate 1.0mL/min

Measurement time 40min

Detector Shodex RI-71S

Temperature 40.0 deg.C

Sample volume sample loop 100 μ L

The sample concentration was adjusted so as to be about 1 mass% in a THF solution

(acid value)

The acid value of the resin was measured by the following method.

About 1g of a sample was precisely weighed in a 100ml flask by a precision balance, and 30ml of methanol was added thereto for dissolution. Further, as an indicator, 1 to 3 drops of phenolphthalein ethanol solution was added, and the mixture was sufficiently stirred until the sample became homogeneous. This was titrated with a 0.1N potassium hydroxide-ethanol solution, and the end point of neutralization was determined when the reddish color of the indicator lasted for 30 seconds. From the results, the value obtained by using the following calculation formula was defined as the acid value of the resin.

Acid value (mgKOH/g) [ B × f × 5.611 ]/S

B: amount of 0.1N Potassium hydroxide-ethanol solution used (ml)

f: factor of 0.1N potassium hydroxide-ethanol solution

S: sample Collection volume (g)

(TG-DTA)

The differential thermal-thermogravimetric measurement was performed under the following measurement conditions.

Measurement apparatus TG/DTA6200(エスアイアイ, ナノテクノロジー, Inc.) as a simultaneous measurement apparatus for differential thermogravimetry

Temperature range 30 ℃ to 500 DEG C

Temperature rise rate 10 ℃/min

Atmospheric nitrogen atmosphere

< Metal salt of polyurethane containing Polypropylene glycol 1000 (acid value: 40mgKOH/g) >

Synthesis example 1 (Synthesis of polyurethane PU-1 having carboxyl group)

Into a 500mL 4-neck separable flask equipped with a dropping funnel, a stirring device, a thermocouple for temperature measurement, and a Liebez cooling tube, 62.11g (62mmol, 0.45 equivalent to diisocyanate) of polypropylene glycol 1000 (weight average molecular weight 1000, manufactured by Nichizhi oil Co., Ltd.) as a diol compound, 11.42g (77mmol, 0.55 equivalent to diisocyanate) of dimethylolbutyric acid (hereinafter abbreviated as DMBA) (manufactured by Nippon chemical Co., Ltd.) as a dihydroxy compound having a carboxyl group, and 104.41g of ethylcarbitol acetate (manufactured by ダイセル) (manufactured by Nippon chemical Co., Ltd.) as a solvent were charged, and all the raw materials were dissolved at 45 ℃. 30.89g (139mmol) of isophorone diisocyanate (hereinafter abbreviated as IPDI) (デスモジュール (registered trademark) I, manufactured by KANTO バイエルウレタン Co., Ltd.) as a diisocyanate compound was added dropwise over 5 minutes using a dropping funnel. After the completion of the dropwise addition, the temperature was raised to 110 ℃ over 1 hour, and the reaction was continued at 110 ℃ for 5 hours. Confirmed by infrared absorption spectrum at 2270cm^-1After the absorption spectrum of the isocyanate group was substantially disappeared, 0.17g of isobutanol as a blocking agent (manufactured by Wako pure chemical industries, Ltd.) was added thereto, and the mixture was reacted at 110 ℃ for 1 hour, and then cooled to room temperature to obtain a uniform polyurethane solution having a carboxyl group. The solid content concentration determined by heating under reduced pressure using a vacuum dryer (120 ℃ C., 3 hours) was 50% by mass.

The obtained polyurethane has a structural unit represented by the following formula (7).

In the formula, x1+ y1 is 1, x1 is 0.55, and y1 is 0.45. n is₆Is a positive integer of about 17 in view of the value of the weight average molecular weight.

The solid content of the obtained carboxyl group-containing polyurethane solution had an acid value of 43mgKOH/g and a weight-average molecular weight of 1.2X 10⁴。

Example 1

(Synthesis of silver polyurethane salt PU-1Ag1 Using silver nitrate)

2.03g (containing 0.73mmol of carboxyl groups) of the carboxyl group-containing polyurethane solution obtained in Synthesis example 1 was dissolved in 20ml of acetone (manufactured by Wako pure chemical industries, Ltd.), and 3ml of water was added thereto and stirred until the solution became homogeneous, the solution being 0.03g (0.73mmol) of sodium hydroxide (manufactured by Wako pure chemical industries, Ltd.). To this solution, 0.13g (0.73mmol) of silver nitrate (manufactured by Wako pure chemical industries, Ltd.) dissolved in 5ml of water was added dropwise to generate a precipitate. The supernatant was removed by decantation, air-dried overnight, and dried under reduced pressure using a vacuum drier for 1 hour while heating at 100 ℃ to completely remove the residual solvent, to obtain a silver salt of polyurethane (yield 0.56 g).

The results of the differential thermal-thermogravimetry (TG-DTA) of the polyurethane silver salt are shown in FIG. 1. The mass ratio of the residue after the completion of the TG-DTA measurement was 9.9 mass%, which is a value close to 7.4 mass% which is a theoretical value of the silver content calculated from the molecular formula.

Example 2

(Synthesis of silver polyurethane salt PU-1Ag2 Using silver oxide)

6.04g (containing 2.2mmol of carboxyl groups) of the carboxyl group-containing polyurethane solution obtained in Synthesis example 1 was dissolved in 14.05g of diethylene glycol monoethyl ether (manufactured by Wako pure chemical industries, Ltd.), and 0.26g of silver oxide (manufactured by Wako pure chemical industries, Ltd.) (1.1mmol, 2.2mmol in terms of silver) was added. After stirring for 10 hours at room temperature in the shade, it was confirmed that the silver oxide disappeared and became a uniform solution.

A part of the obtained silver salt solution (solid content concentration: 16% by mass) was dried under reduced pressure for 1 hour by using a vacuum dryer while heating at 100 ℃. After drying, TG-DTA measurement of the obtained solid silver urethane salt was carried out. The measurement results are shown in fig. 2. The mass ratio of the residue after the completion of the TG-DTA measurement was 8.1 mass%, which is a value close to 7.4 mass% which is a theoretical value of the silver content calculated from the molecular formula. As is confirmed from fig. 1 and 2, the same material was obtained for the silver urethane salt obtained by the method using silver nitrate and the silver urethane salt obtained by the method using silver oxide.

In order to confirm that the silver atom coordinates to the carboxyl group portion of the resin, IR measurement of the obtained solid was performed. The IR spectrum of the polyurethane obtained in synthesis example 1 is shown in fig. 3, and the IR spectrum of the silver salt of polyurethane obtained in example 1 is shown in fig. 4. It is generally known that 1600cm is a length of a coordination structure in which a salt is formed with a carboxylic acid and a C ═ O double bond and a C-O single bond in a carboxyl group are equivalent^-1Near and 1400cm^-1A peak was observed in the vicinity. In comparison between fig. 3 and fig. 4, such a change is not observed, and therefore, it is suggested that the silver atom is coordinated to only one oxygen atom in the silver salt.

In order to confirm that the silver atom is coordinated to the carboxyl group portion of the resin, NMR measurement was performed in addition to the above IR measurement. Preparation of the resin obtained in Synthesis example 1¹The H-NMR spectrum is shown in FIG. 5, which shows the silver salt of polyurethane obtained in example 1¹The H-NMR spectrum is shown in FIG. 6. To prevent the contamination of water, the sample was dried under reduced pressure for 1 hour using a vacuum dryer immediately before the measurement, and deuterated dimethyl sulfoxide filled in an ampoule was used as the deuterated solvent. As a result, the peak of the carboxyl group observed in the vicinity of 12ppm in fig. 5 disappeared in fig. 6, and it was confirmed that the silver atom was coordinated to the carboxyl group portion.

The silver salt of the polyurethane thus obtained has a structural unit represented by the following formula (8).

In the formula, x1+ y1 is 1, x1 is 0.55, and y1 is 0.45. n is₆Is a positive integer of about 17 in view of the value of the weight average molecular weight.

Example 3

(Synthesis of copper polyurethane salt PU-1Cu Using copper sulfate)

2.02g (containing 0.73mmol of carboxyl groups) of the carboxyl group-containing polyurethane solution obtained in Synthesis example 1 was dissolved in 20ml of acetone (manufactured by Wako pure chemical industries, Ltd.), and 0.03g (0.73mmol) of sodium hydroxide (manufactured by Wako pure chemical industries, Ltd.) was dissolved in 3ml of water, followed by stirring until the mixture became homogeneous. To this solution, 0.092g (0.37mmol, 0.5 equivalent to the carboxyl group) of copper sulfate pentahydrate (manufactured by Wako pure chemical industries, Ltd.) dissolved in 5ml of water was added dropwise to generate a precipitate. After stirring at room temperature for 2 hours, the supernatant was removed by decantation, and dried under reduced pressure using a vacuum drier for 1 hour while heating at 100 ℃ to completely remove the residual solvent, to obtain a copper salt of polyurethane (yield 0.62 g).

The results of TG-DTA measurement of the obtained copper salt are shown in FIG. 7. The mass ratio of the residue after the completion of the TG-DTA measurement was 2.3 mass%, which agrees with 2.3 mass% which is a theoretical value of the copper content calculated from the molecular formula.

In order to confirm that the copper atom coordinates to the carboxyl group portion of the resin, IR measurement of the obtained solid was performed. An IR spectrum of the copper salt of polyurethane obtained in example 3 is shown in fig. 8. If FIG. 3 is compared with FIG. 8, 1618cm is shown in FIG. 8^-1And 1410cm^-1A new peak was observed, and therefore, it was confirmed that the copper atom forms a salt with the carboxyl group, and the C ═ O double bond and the C — O single bond are equivalent coordination structures.

The copper salt of the polyurethane thus obtained has a structural unit represented by the following formula (9). For the sake of simplicity, the following formula shows only the coordination structure around the copper atom.

Wherein the dotted line represents a coordinate bond. The urethane bond units crosslinked by copper atoms may be contained in the same polyurethane skeleton, or may be contained in different polyurethane skeletons. In fact, divalent copper atoms are substitution-active metal species, and therefore it is considered that polyurethane chains crosslinked by copper atoms are exchanged with time. Further, it is considered that there is a possibility that a lantern type dinuclear coordination compound in which 4 carboxyl groups are coordinated to 2 copper atoms is partially generated, but in any case, the ratio of the carboxyl groups to the copper atoms is 2: 1 form a salt.

Silver salt of polyurethane containing polyethylene glycol 400

Synthesis example 2 (Synthesis of polyurethane PU-2 having carboxyl group)

In a 500mL 4-neck separable flask equipped with a dropping funnel, a stirring device, a thermocouple for temperature measurement, and a Liebez cooling tube, 24.95g (62mmol, 0.45 equivalent to diisocyanate) of polyethylene glycol 400 (weight average molecular weight 400, manufactured by Nichisu oil Co., Ltd.) as a diol compound, 11.41g (77mmol, 0.55 equivalent to diisocyanate) of DMBA (manufactured by Nippon chemical Co., Ltd.) as a dihydroxy compound having a carboxyl group, and 100.90g of ethylcarbitol acetate (manufactured by ダイセル Co., Ltd.) as a solvent were charged, and all the raw materials were dissolved at 55 ℃. 30.90g (139mmol) of IPDI (デスモジュール (registered trademark) I, manufactured by Suzuki バイエルウレタン Co., Ltd.) as a diisocyanate was added dropwise over 5 minutes using a dropping funnel. After the completion of the dropwise addition, the temperature was raised to 110 ℃ over 1 hour, and the reaction was continued at 110 ℃ for 5 hours. Confirmed by infrared absorption spectrum at 2270cm^-1After the absorption spectrum of the isocyanate group was substantially disappeared, 0.17g of isobutanol as a blocking agent (manufactured by Wako pure chemical industries, Ltd.) was added thereto, and the mixture was reacted at 110 ℃ for 1 hour, and then cooled to room temperature to obtain a uniform polyurethane solution having a carboxyl group. The solid content concentration determined by heating under reduced pressure using a vacuum dryer (120 ℃ C., 2 hours) was 40% by mass.

The polyurethane obtained has a structural unit represented by the following formula (10).

In the formula, x2+ y2 is 1, x2 is 0.55, and y2 is 0.45. n is₇Is a positive integer of about 9 in view of the value of the weight average molecular weight.

The solid content of the obtained carboxyl group-containing polyurethane solution had an acid value of 65mgKOH/g and a weight-average molecular weight of 1.0X 10⁴。

Example 4

(silver polyurethane salt PU-2Ag Using silver nitrate₁Synthesis of (2)

2.53g (containing 1.1mmol of carboxyl groups) of the carboxyl group-containing polyurethane solution obtained in Synthesis example 2 was dissolved in 20ml of acetone (manufactured by Wako pure chemical industries, Ltd.), and 0.046g (1.1mmol) of sodium hydroxide (manufactured by Wako pure chemical industries, Ltd.) was added to 5ml of water, followed by stirring until the mixture became homogeneous. To this solution, 0.20g (1.1mmol) of silver nitrate (manufactured by Wako pure chemical industries, Ltd.) dissolved in 5ml of water was added dropwise to generate a precipitate. After stirring at room temperature for 30 minutes, the supernatant was removed by decantation, air-dried overnight, and then dried under reduced pressure using a vacuum drier for 1 hour while heating at 100 ℃ to completely remove the residual solvent, to obtain a silver salt of polyurethane (yield 0.47 g).

The results of TG-DTA measurement of the polyurethane silver salt are shown in FIG. 9. The mass ratio of the residue after the completion of the TG-DTA measurement was 15.2 mass%, which is a value close to 11.0 mass% which is a theoretical value of the silver content calculated from the molecular formula.

Example 5

(silver urethane salt PU-2Ag Using silver oxide₂Synthesis of (2)

5.02g (containing 2.2mmol of carboxyl groups) of the carboxyl group-containing polyurethane solution obtained in Synthesis example 2 was dissolved in 15.02g of diethylene glycol monoethyl ether (manufactured by Wako pure chemical industries, Ltd.), and 0.26g of silver oxide (manufactured by Wako pure chemical industries, Ltd.) (1.1mmol, 2.2mmol in terms of silver) was added. After stirring for 15 hours at room temperature in the shade, it was confirmed that the silver oxide disappeared and became a uniform solution.

A part of the obtained silver salt solution of polyurethane (solid content concentration: 11% by mass) was dried under reduced pressure for 1 hour by a vacuum dryer while being heated at 100 ℃. The TG-DTA measurement of the obtained solid silver salt was performed after drying. The measurement results are shown in fig. 10. The mass ratio of the residue after the completion of the TG-DTA measurement was 10.9 mass%, which is a value close to 11.0 mass% which is a theoretical value of the silver content calculated from the molecular formula. As is confirmed from fig. 9 and 10, the same material was obtained for the silver urethane salt obtained by the method using silver nitrate and the silver urethane salt obtained by the method using silver oxide.

The silver salt of the polyurethane thus obtained has a structural unit represented by the following formula (11).

In the formula, x2+ y2 is 1, x2 is 0.55, and y2 is 0.45. n is₇Is a positive integer of about 9 in view of the value of the weight average molecular weight.

Silver salt of carboxyl group-containing polyurethane formed from DMBA and IPDI

Synthesis example 3 (Synthesis of polyurethane PU-3)

20.59g (139mmol, 1.0 equivalent to diisocyanate) of DMBA (manufactured by Takeku Seisakusho Co., Ltd.) as a dihydroxy compound having a carboxyl group and 120.27g of ethylcarbitol acetate (manufactured by ダイセル, Ltd.) as a solvent were put into a 500mL 4-neck separable flask equipped with a dropping funnel, a stirring device, a thermocouple for temperature measurement and a Liebez cooling tube, and after confirming that DMBA was dissolved at 65 ℃, 30.97g (139mmol) of IPDI (manufactured by バイエルウレタン, デスモジュール (registered trademark) I) as a diisocyanate compound was dropped over 5 minutes using the dropping funnel. After the completion of the dropwise addition, the reaction solution was heated up to 110 ℃ over 1 hour, and then the reaction was continued at 110 ℃ for 5 hours. Confirmed by infrared absorption spectrum at 2270cm^-1After the absorption spectrum of the isocyanate group was substantially disappeared, 0.17g of isobutanol as a blocking agent (manufactured by Wako pure chemical industries, Ltd.) was added thereto, and the mixture was reacted at 110 ℃ for 1 hour, and then cooled to room temperature, whereby 91.21g of a viscous paste-like urethane composition having a carboxyl group was precipitated. The solid content concentration determined by heating under reduced pressure using a vacuum dryer (120 ℃ C., 2 hours) was 54% by mass.

The structural unit of the polyurethane obtained is represented by the following formula (12).

In the formula, n₈Is a positive integer of about 18 in view of the value of the weight average molecular weight.

The obtained pasty carboxyl group-containing polyurethane composition had an acid value of 150mgKOH/g as a solid component and a weight-average molecular weight of 6.5X 10³。

Example 6

(polyurethane silver salt PU-3 Ag)₁Synthesis of (2)

1.74g (containing 2.6mmol of carboxyl groups) of the pasty carboxyl group-containing polyurethane composition obtained in Synthesis example 3 was dissolved in 30ml of methanol (manufactured by Wako pure chemical industries, Ltd.), and 0.10g (2.6mmol) of sodium hydroxide (manufactured by Wako pure chemical industries, Ltd.) was added to 1ml of water, followed by stirring until the mixture became homogeneous. To this solution, 0.44g (2.6mmol) of silver nitrate (manufactured by Wako pure chemical industries, Ltd.) dissolved in 5ml of water was added dropwise to generate a precipitate, and the resulting solution was stirred at room temperature for 30 minutes. The precipitate was suction-filtered, and dried under reduced pressure for 1 hour by a vacuum drier while heating at 110 ℃ to completely remove the residual solvent, to obtain a silver salt of polyurethane (yield 0.72 g).

The structural unit of the silver salt of the polyurethane is represented by the following formula (13).

In the formula, n₈Is a positive integer of about 18 in view of the value of the weight average molecular weight.

The results of TG-DTA measurement of the obtained silver polyurethane salt are shown in FIG. 11. The mass ratio of the residue after the completion of the TG-DTA measurement was 20.5 mass%, which is a value close to the theoretical value of the silver content calculated from the molecular formula of 22.6 mass%.

Silver salt of polyurethane containing 2-butyl-2-ethyl-1, 3-propanediol

Synthesis example 4 (Synthesis of polyurethane PU-4)

A500 mL 4-neck separable flask equipped with a dropping funnel, a stirring device, a thermocouple for temperature measurement, and a Liebez cooling tube was charged into the flask8.81g (55mmol, 0.4 equivalent to diisocyanate) of 2-butyl-2-ethyl-1, 3-propanediol (manufactured by Tokyo Kasei Kogyo Co., Ltd.) as a diol compound, 12.45g (84mmol, 0.6 equivalent to diisocyanate) of DMBA (manufactured by Takara Shuzo Co., Ltd.) as a dihydroxy compound having a carboxyl group, and 121.70g of ethyl carbitol acetate (manufactured by ダイセル Co., Ltd.) as a solvent were dissolved at 50 ℃. 30.90g (139mmol) of IPDI (デスモジュール (registered trademark) I, manufactured by Tokyo バイエルウレタン Co., Ltd.) as a diisocyanate compound was added dropwise over 5 minutes using a dropping funnel. After the completion of the dropwise addition, the temperature was raised to 110 ℃ over 1 hour, and the reaction was continued at 110 ℃ for 5 hours. Confirmed by infrared absorption spectrum at 2270cm^-1After the absorption spectrum of the isocyanate group was substantially disappeared, 0.17g of isobutanol as a blocking agent (manufactured by Wako pure chemical industries, Ltd.) was added thereto, and the mixture was reacted at 110 ℃ for 1 hour, and then cooled to room temperature to obtain a uniform polyurethane solution having a carboxyl group. The solid content concentration determined by heating under reduced pressure using a vacuum dryer (120 ℃ C., 2 hours) was 30% by mass.

The obtained polyurethane has a structural unit represented by the following formula (14).

In the formula, x3+ y3 is 1, x3 is 0.60, and y3 is 0.40. In the formula, Et represents an ethyl group, and Bu represents an n-butyl group.

The solid content of the resulting carboxyl group-containing polyurethane solution had an acid value of 93mgKOH/g and a weight-average molecular weight of 9.0X 10³。

Example 7

(polyurethane silver salt PU-4 Ag)₁Synthesis of (2)

1.56g (containing 0.78mmol of carboxyl groups) of the carboxyl group-containing polyurethane solution obtained in Synthesis example 4 was dissolved in 10ml of ethanol (manufactured by Wako pure chemical industries, Ltd.), and 3ml of water was added thereto and stirred until the mixture became homogeneous, the solution being 0.03g (0.78mmol) of sodium hydroxide (manufactured by Wako pure chemical industries, Ltd.). To this solution, 0.12g (0.78mmol) of silver nitrate (manufactured by Wako pure chemical industries, Ltd.) dissolved in 5ml of water was added dropwise to generate a precipitate, and the resulting solution was stirred at room temperature for 30 minutes. The precipitate was suction-filtered, and dried under reduced pressure for 1 hour by a vacuum drier while heating at 110 ℃ to completely remove the residual solvent, to obtain a silver salt of polyurethane (yield 0.41 g).

The results of TG-DTA measurement of the silver salt thus obtained are shown in FIG. 12. The mass ratio of the residue after the TG-DTA measurement was 14.8% by mass, which is in agreement with 14.8% of the theoretical value of the silver content calculated from the molecular formula.

The silver salt of the polyurethane thus obtained has a structural unit represented by the following formula (15).

In the formula, x3+ y3 is 1, x3 is 0.60, and y3 is 0.40. In the formula, Et represents an ethyl group, and Bu represents an n-butyl group.

< silver salt of polyurethane containing Polypropylene glycol 1000 (acid value: 90mgKOH/g) >)

Synthesis example 5 (Synthesis of polyurethane PU-5)

In a 500mL 4-neck separable flask equipped with a dropping funnel, a stirring device, a thermocouple for temperature measurement, and a Liebez cooling tube, 24.06g (24mmol, 0.17 equivalent to diisocyanate) of polypropylene glycol 1000 (weight average molecular weight 1000, manufactured by Nichisu oil Co., Ltd.) as a diol compound, 17.04g (115mmol, 0.83 equivalent to diisocyanate) of DMBA (manufactured by Nippon chemical Co., Ltd.) as a dihydroxy compound having a carboxyl group, and 108.04g of ethyl carbitol acetate (manufactured by ダイセル Co., Ltd.) as a solvent were charged, and all the raw materials were dissolved at 60 ℃. 30.88g (139mmol) of IPDI (デスモジュール (registered trademark) I, manufactured by Tokyo バイエルウレタン Co., Ltd.) as a diisocyanate compound was added dropwise over 5 minutes using a dropping funnel. After the completion of the dropwise addition, the temperature was raised to 110 ℃ over 1 hour, and the reaction was continued at 110 ℃ for 5 hours. Confirmed by infrared absorption spectrum at 2270cm^-1ObservedAfter the absorption spectrum of the isocyanate group had substantially disappeared, 0.17g of isobutanol as a blocking agent (manufactured by Wako pure chemical industries, Ltd.) was added thereto, and the mixture was reacted at 110 ℃ for 1 hour, and then allowed to cool to room temperature to obtain a uniform polyurethane solution having a carboxyl group. The solid content concentration determined by heating under reduced pressure using a vacuum dryer (120 ℃ C., 2 hours) was 38% by mass.

The polyurethane obtained has a structural unit represented by the following formula (16).

In the formula, x4+ y4 is 1, x4 is 0.83, and y4 is 0.17. n is₉Is a positive integer of about 17 in view of the value of the weight average molecular weight.

The measured value of the acid value of the solid content of the resulting carboxyl group-containing polyurethane solution was 85mgKOH/g, and the weight-average molecular weight was 9.4X 10³。

Example 8

(polyurethane silver salt PU-5 Ag)₁Synthesis of (2)

2.00g (containing 1.3mmol of carboxyl groups) of the carboxyl group-containing polyurethane solution obtained in Synthesis example 5 was dissolved in 20ml of acetone (manufactured by Wako pure chemical industries, Ltd.), and 0.05g (1.3mmol) of sodium hydroxide (manufactured by Wako pure chemical industries, Ltd.) was dissolved in 5ml of water, followed by stirring until the mixture became homogeneous. To this solution, 0.23g (1.3mmol) of silver nitrate (manufactured by Wako pure chemical industries, Ltd.) dissolved in 5ml of water was added dropwise to generate a precipitate. After stirring at room temperature for 30 minutes, the supernatant was removed by decantation. In order to completely remove the residual solvent, the reaction mixture was dried under reduced pressure using a vacuum dryer for 1 hour while heating at 100 ℃ to obtain a silver salt of polyurethane (yield 0.56 g).

The results of TG-DTA measurement of the obtained silver polyurethane salt are shown in FIG. 13. The mass ratio of the residue after the completion of the TG-DTA measurement was 20.6 mass%, which is a value close to 14.7 mass% of the theoretical value of the silver content calculated from the molecular formula.

The silver salt of the polyurethane thus obtained has a structural unit represented by the following formula (17).

In the formula, x4+ y4 is 1, x4 is 0.83, and y4 is 0.17. n is₉Is a positive integer of about 17 in view of the value of the weight average molecular weight.

Silver salt of polyurethane containing polycarbonate diol

Synthesis example 6 (Synthesis of polyurethane PU-6)

To a 500mL 4-neck separable flask equipped with a dropping funnel, a stirring device, a thermocouple for temperature measurement, and a Liebez cooling tube were charged 31.20g (62mmol, 0.45 equivalent to diisocyanate) of polycarbonate diol (weight average molecular weight 500, manufactured by Asahi Kasei ケミカルズ Co., Ltd., デュラノール (registered trademark) T5650E) as a diol compound, 11.41g (77mmol, 0.55 equivalent to diisocyanate) of DMBA (manufactured by Wako Junyaku chemical Co., Ltd.) as a dihydroxy compound having a carboxyl group, and 73.50g of ethyl carbitol acetate (manufactured by ダイセル Co., Ltd.) as a solvent, and all the raw materials were dissolved at 55 ℃. Using a dropping funnel, 30.96g (139mmol) of IPDI (デスモジュール (registered trademark) I, manufactured by Tokusho バイエルウレタン Co., Ltd.) as a diisocyanate compound was added dropwise over 5 minutes. After the completion of the dropwise addition, the temperature was raised to 110 ℃ over 1 hour, and the reaction was continued at 110 ℃ for 5 hours. Confirmed by infrared absorption spectrum at 2270cm^-1After the absorption spectrum of the isocyanate group was substantially disappeared, 0.19g of isobutanol as a blocking agent (manufactured by Wako pure chemical industries, Ltd.) was added thereto, and the mixture was reacted at 110 ℃ for 1 hour, and then cooled to room temperature to obtain a uniform polyurethane solution having a carboxyl group. The solid content concentration determined by reduced-pressure heat drying using a vacuum dryer (drying at 120 ℃ C. for 5 hours, and then at 135 ℃ C. for 1 hour) was 50% by mass.

The solid content of the resulting carboxyl group-containing polyurethane solution had an acid value of 62mgKOH/g and a weight-average molecular weight of 2.6X 10⁴。

The obtained polyurethane has a structural unit represented by the following formula (18).

In the formula, x5+ y5 is 1, x5 is 0.55, and y5 is 0.45. n is₁₀Is a positive integer, and is about 3 in view of the value of the weight average molecular weight. Furthermore R⁹Is an aliphatic hydrocarbon group having 5 or 6 carbon atoms.

(Synthesis of a polyurethane silver salt PU-6Ag having silver atoms bonded to part or all of the carboxyl groups)

The polyurethane solution obtained in synthesis example 6 was reacted with silver oxide to obtain a silver salt in which silver atoms and a part or all of carboxyl groups were bonded. The ratio of the formed silver salt is difficult to accurately determine by an experimental method such as IR spectrometry, NMR spectrometry, or acid value titration, and therefore, a value calculated from the addition ratio of the raw material under visual confirmation that the added silver oxide is completely dissolved (complete reaction) is used.

Example 9

(silver urethane salt PU-6Ag having silver atoms bonded to 8% of carboxyl groups₍₈₎Synthesis of (2)

4.01g (containing 2.10mmol of carboxyl groups) of the carboxyl group-containing polyurethane solution obtained in Synthesis example 6 was dissolved in 5.96g of diethylene glycol monoethyl ether (manufactured by Wako pure chemical industries, Ltd.), and 0.02g of silver oxide (0.16 mmol as Ag, manufactured by Wako pure chemical industries, Ltd.) was added. After stirring for 6 hours at room temperature in the shade, it was confirmed that the silver oxide disappeared and became a uniform solution.

A part of the obtained silver salt solution of polyurethane (solid content concentration: 21% by mass) was dried under reduced pressure for 2 hours by a vacuum dryer while being heated at 120 ℃. After drying, TG-DTA measurement of the obtained solid silver urethane salt was carried out. The measurement results are shown in fig. 14. The mass ratio of the residue after the completion of the TG-DTA measurement was 2.0 mass%, which is a value close to 0.8 mass% which is a theoretical value of the silver content calculated from the molecular formula.

Example 10

(silver urethane salt PU-6Ag having 63% of the silver atoms and carboxyl groups bound thereto₍₆₃₎Synthesis of (2)

2.06g (containing 1.08mmol of carboxyl groups) of the carboxyl group-containing polyurethane solution obtained in Synthesis example 6 was dissolved in 7.99g of diethylene glycol monoethyl ether (manufactured by Wako pure chemical industries, Ltd.), and 0.08g of silver oxide (0.68 mmol as Ag, manufactured by Wako pure chemical industries, Ltd.) was added. After stirring for 6 hours at room temperature in the shade, it was confirmed that the silver oxide disappeared and became a uniform solution.

A part of the obtained silver salt solution of polyurethane (solid content concentration: 11% by mass) was dried under reduced pressure for 2 hours by a vacuum dryer while being heated at 120 ℃. The TG-DTA measurement of the obtained solid silver salt was performed after drying. The measurement results are shown in fig. 15. The mass ratio of the residue after the completion of the TG-DTA measurement was 8.5 mass%, which is a value close to 6.4 mass% which is a theoretical value of the silver content calculated from the molecular formula.

Example 11

(silver urethane salt PU-6Ag having 50% of the silver atoms bonded to the carboxyl groups₍₅₀₎Synthesis of (2)

8.00g (containing 4.20mmol of carboxyl groups) of the carboxyl group-containing polyurethane solution obtained in Synthesis example 6 was dissolved in 8.01g of diethylene glycol monoethyl ether (manufactured by Takara Shuzo Co., Ltd.). Subsequently, 0.25g of silver oxide (2.10 mmol of Ag, manufactured by Wako pure chemical industries, Ltd.) was dispersed in 4.06g of diethylene glycol monoethyl ether (manufactured by Takara Shuzo Co., Ltd.), and the dispersion was added to a polyurethane solution. After stirring at 85 ℃ for 10 hours, it was confirmed that the silver oxide disappeared and became a uniform solution.

A part of the obtained silver salt solution of polyurethane (solid content concentration: 23% by mass) was dried under reduced pressure for 2 hours by a vacuum dryer while being heated at 120 ℃. The TG-DTA measurement of the obtained solid silver salt was performed after drying. The measurement results are shown in fig. 16. The mass ratio of the residue after the completion of the TG-DTA measurement was 5.5 mass%, which is a value close to 5.1 mass% which is a theoretical value of the silver content calculated from the molecular formula.

Example 12

(silver urethane salt PU-6Ag having silver atoms 100% bonded to carboxyl groups₍₁₀₀₎Synthesis of (2)

8.00g (containing 4.20mmol of carboxyl groups) of the carboxyl group-containing polyurethane solution obtained in Synthesis example 6 was dissolved in 8.00g of diethylene glycol monoethyl ether (manufactured by Takara Shuzo Co., Ltd.). Subsequently, 0.49g of silver oxide (4.20 mmol of Ag, manufactured by Wako pure chemical industries, Ltd.) was dispersed in 4.01g of diethylene glycol monoethyl ether (manufactured by Takara Shuzo Co., Ltd.), and the dispersion was added to a polyurethane solution. After stirring at 85 ℃ for 10 hours, it was confirmed that the silver oxide disappeared and became a uniform solution.

A part of the obtained silver salt solution of polyurethane (solid content concentration: 23% by mass) was dried under reduced pressure for 2 hours by a vacuum dryer while being heated at 120 ℃. The TG-DTA measurement of the obtained solid silver salt was performed after drying. The measurement results are shown in fig. 17. The mass ratio of the residue after the completion of the TG-DTA measurement was 9.5 mass%, which is a value close to 10.2 mass% which is a theoretical value of the silver content calculated from the molecular formula.

The silver salt of the polyurethane obtained by bonding a silver atom to a part or all of the carboxyl groups has a structural unit represented by the following formula (19).

In the formula, x6+ x7+ y5 is 1, in example 9, x6 is 0.04, x7 is 0.51, and y5 is 0.45. In example 10, x6 is 0.35, x7 is 0.20, and y5 is 0.45. In example 11, x6 is 0.275, x7 is 0.275, and y5 is 0.45. In example 12, x6 is 0.55, x7 is 0, and y5 is 0.45. n is₁₀Is a positive integer, and is about 3 in view of the value of the weight average molecular weight. Furthermore R⁹Is an aliphatic hydrocarbon group having 5 or 6 carbon atoms.

Silver salt of polycarbonate diol-containing polyurethane with DMBA as DMPA (dimethylolpropionic acid) >

Synthesis example 7 (Synthesis of polyurethane PU-7)

The stirring device is provided with a dropping funnelA500 mL 4-neck separable flask equipped with a thermocouple for measuring temperature and a Liebez cooling tube was charged with 31.19g (62mmol, 0.45 equivalent to diisocyanate) of polycarbonate diol (weight average molecular weight 500, product name デュラノール T5650E of Asahi Kasei ケミカルズ Co., Ltd.), 10.13g (77mmol, 0.55 equivalent to diisocyanate) of DMPA (product name of Tokyo Kasei Co., Ltd.) as a dihydroxy compound having a carboxyl group, and 72.40g of ethyl carbitol acetate (product name ダイセル Co., Ltd.) as a solvent, and heated to 55 ℃. 30.92g (139mmol) of IPDI (デスモジュール (registered trademark) I, manufactured by Tokusho バイエルウレタン Co., Ltd.) as a diisocyanate compound was added dropwise over 10 minutes using a dropping funnel. After the end of the dropwise addition, the temperature was raised to 110 ℃ over 1 hour, and after complete dissolution of DMPA, the reaction was continued at 110 ℃ for 5 hours. Confirmed by infrared absorption spectrum at 2270cm^-1After the absorption spectrum of the isocyanate group was substantially disappeared, 0.22g of isobutanol as a blocking agent (manufactured by Wako pure chemical industries, Ltd.) was added thereto, and the mixture was reacted at 110 ℃ for 1 hour, and then cooled to room temperature to obtain a uniform polyurethane solution having a carboxyl group. The solid content concentration determined by reduced-pressure heat drying (drying at 120 ℃ C. for 4 hours) using a vacuum dryer was 51% by mass.

The solid content of the resulting carboxyl group-containing polyurethane solution had an acid value of 59mgKOH/g and a weight-average molecular weight of 2.8X 10⁴。

The obtained polyurethane has a structural unit represented by the following formula (20).

In the formula, x8+ y6 is 1, x8 is 0.55, and y6 is 0.45. n is₁₁Is a positive integer, and is about 3 in view of the value of the weight average molecular weight. Furthermore R¹⁰Is an aliphatic hydrocarbon group having 5 or 6 carbon atoms.

Example 13

(Synthesis of polyurethane silver salt PU-7 Ag)

8.00g (containing 4.20mmol of carboxyl groups) of the carboxyl group-containing polyurethane solution obtained in Synthesis example 7 was dissolved in 7.99g of diethylene glycol monoethyl ether (manufactured by Takara Shuzo Co., Ltd.). Subsequently, 0.49g of silver oxide (4.20 mmol of Ag, manufactured by Wako pure chemical industries, Ltd.) was dispersed in 4.00g of diethylene glycol monoethyl ether (manufactured by Takara Shuzo Co., Ltd.), and the dispersion was added to a polyurethane solution. After stirring at 85 ℃ for 5 hours, it was confirmed that the silver oxide disappeared and became a uniform solution.

A part of the obtained silver salt solution of polyurethane (solid content concentration: 23% by mass) was dried under reduced pressure for 2 hours by a vacuum dryer while being heated at 100 ℃. The TG-DTA measurement of the obtained solid silver salt was performed after drying. The measurement results are shown in fig. 18. The mass ratio of the residue after the completion of the TG-DTA measurement was 9.4 mass%, which is a value close to 10.3 mass% which is a theoretical value of the silver content calculated from the molecular formula.

The silver salt of the polyurethane thus obtained has a structural unit represented by the following formula (21).

In the formula, x8+ y6 is 1, x8 is 0.55, and y6 is 0.45. n is₁₁Is a positive integer, and is about 3 in view of the value of the weight average molecular weight. Furthermore R¹⁰Is an aliphatic hydrocarbon group having 5 or 6 carbon atoms.

Synthesis example 8 silver salt of polyurethane containing polyethylene glycol 1000

(Synthesis of polyurethane PU-8)

To a 500mL 4-neck separable flask equipped with a dropping funnel, a stirring device, a thermocouple for temperature measurement, and a Liebez cooling tube were charged 62.72g (62mmol, 0.45 equivalent to diisocyanate) of polyethylene glycol 1000 (weight average molecular weight 1000, manufactured by Nichio oil Co., Ltd.) as a diol compound, 11.41g (77mmol, 0.55 equivalent to diisocyanate) of DMBA (manufactured by Huzhou Seisakusho chemical Co., Ltd.) as a dihydroxy compound having a carboxyl group, 105.05g of ethyl carbitol acetate (manufactured by ダイセル Co., Ltd.) as a solvent, and the mixture was stirred at 5 ℃ CAll raw materials were dissolved at 5 ℃. 30.91g (139mmol) of IPDI (デスモジュール (registered trademark) I, manufactured by Tokusho バイエルウレタン Co., Ltd.) as a diisocyanate compound was added dropwise over 5 minutes using a dropping funnel. After the completion of the dropwise addition, the temperature was raised to 110 ℃ over 1 hour, and the reaction was continued at 110 ℃ for 5 hours. Confirmed by infrared absorption spectrum at 2270cm^-1After the absorption spectrum of the isocyanate group was substantially disappeared, 0.17g of isobutanol as a blocking agent (manufactured by Wako pure chemical industries, Ltd.) was added thereto, and the mixture was reacted at 110 ℃ for 1 hour, and then cooled to room temperature to obtain a uniform polyurethane solution having a carboxyl group. The solid content concentration determined by reduced-pressure heat drying (drying at 120 ℃ C. for 1 hour) using a vacuum dryer was 51% by mass.

The solid content of the resulting carboxyl group-containing polyurethane solution had an acid value of 42mgKOH/g and a weight-average molecular weight of 1.5X 10⁴。

The obtained polyurethane has a structural unit represented by the following formula (22).

In the formula, x9+ y7 is 1, x9 is 0.55, and y7 is 0.45. n is₁₂Is a positive integer of about 22 in view of the value of the weight average molecular weight.

Example 14

(Synthesis of silver polyurethane salt PU-8Ag (TP) Using terpineol as reaction solvent)

2.01g (containing carboxyl groups corresponding to 0.73mmol) of the carboxyl group-containing polyurethane solution obtained in Synthesis example 8 was dissolved in 8.00g of terpineol C (manufactured by Japan テルペン chemical Co., Ltd.), and 0.08g of silver oxide (manufactured by Wako pure chemical industries, Ltd., Ag: 0.73mmol) was added thereto. After stirring for 6 hours at room temperature in the shade, it was confirmed that the silver oxide disappeared and became a uniform solution.

A part of the obtained silver salt solution of polyurethane (solid content concentration: 11% by mass) was dried under reduced pressure for 2 hours by a vacuum dryer while being heated at 100 ℃. The TG-DTA measurement of the obtained solid silver salt was performed after drying. The measurement results are shown in fig. 19. The mass ratio of the residue after the completion of the TG-DTA measurement was 7.7 mass%, which is a value close to 7.4 mass% which is a theoretical value of the silver content calculated from the molecular formula.

The silver salt of the polyurethane thus obtained has a structural unit represented by the following formula (23).

In the formula, x9+ y7 is 1, x9 is 0.55, and y7 is 0.45. n is₁₂Is a positive integer of about 22 in view of the value of the weight average molecular weight.

Example 15

(Synthesis of polyurethane silver salt PU-8Ag (ECA/EC) Using ECA/EC as reaction solvent)

2.01g (containing 0.73mmol of carboxyl groups) of the carboxyl group-containing polyurethane solution obtained in Synthesis example 8 was dissolved in 8.00g of diethylene glycol monoethyl ether (manufactured by Wako pure chemical industries, Ltd.), and 0.08g of silver oxide (0.73mmol of Ag, manufactured by Wako pure chemical industries, Ltd.) was added. After stirring for 7 hours at room temperature in the shade, it was confirmed that the silver oxide disappeared and became a uniform solution.

The obtained silver salt solution of polyurethane was dried under reduced pressure while heating by the method shown in example 14, and TG-DTA measurement of the obtained solid silver salt was carried out after drying, and as a result, the same results as those shown in example 14 were obtained.

Example 16

(Synthesis of copper salt of polyurethane Using copper hydroxide PU-8 Cu)

4.02g (containing 1.46mmol of carboxyl groups) of the carboxyl group-containing polyurethane solution obtained in Synthesis example 8 was dissolved in 15.99g of diethylene glycol monoethyl ether (manufactured by Wako pure chemical industries, Ltd.), and 0.07g of copper hydroxide (manufactured by Wako pure chemical industries, Ltd.) (0.73mmol) was added thereto. After heating to 120 ℃ in an oil bath, the mixture was stirred for 6 hours, and it was confirmed that copper hydroxide disappeared and became a uniform solution.

A part of the obtained copper salt polyurethane solution (solid content concentration: 11 mass%) was dried under reduced pressure for 2 hours by a vacuum dryer while heating at 120 ℃. The TG-DTA measurement of the obtained solid silver salt was performed after drying. The measurement results are shown in fig. 20. The mass ratio of the residue after the TG-DTA measurement was 3.2 mass%, which is a value close to 2.3 mass% which is a theoretical value of the copper content calculated from the molecular formula.

The copper salt of the polyurethane thus obtained has a crosslinked structure represented by the formula (9).

(silver salt of polyurethane containing polyethylene glycol 1000 using MDI as diisocyanate)

Synthesis example 9 (Synthesis of polyurethane PU-9)

In a 500mL 4-neck separable flask equipped with a dropping funnel, a stirring device, a thermocouple for temperature measurement, and a Liebez cooling tube, 62.68g (62mmol, 0.45 equivalent to diisocyanate) of polyethylene glycol 1000 (weight average molecular weight 1000, manufactured by Nichio oil Co., Ltd.) as a diol compound, 11.41g (77mmol, 0.55 equivalent to diisocyanate) of DMBA (manufactured by Huzhou chemical Co., Ltd.) as a dihydroxy compound having a carboxyl group, and 108.90g of ethyl carbitol acetate (manufactured by Tokuwa ダイセル Co., Ltd.) as a solvent were charged, and all the raw materials were dissolved at 55 ℃. 34.82g (139mmol) of MDI (product name ルプラネート (registered trademark) MI, manufactured by BASF INOAC ポリウレタン Co., Ltd.) as a diisocyanate compound was added dropwise over 30 minutes using a dropping funnel. After the end of the dropwise addition, the temperature was raised to 110 ℃ over 2 hours, and the reaction was continued at 110 ℃ for 4 hours. Confirmed by infrared absorption spectrum at 2270cm^-1After the absorption spectrum of the isocyanate group was substantially disappeared, 0.17g of isobutanol as a blocking agent (manufactured by Wako pure chemical industries, Ltd.) was added thereto, and the mixture was reacted at 110 ℃ for 1 hour, and then cooled to room temperature to obtain a uniform polyurethane solution having a carboxyl group. The solid content concentration determined by reduced-pressure heat drying (drying at 120 ℃ C. for 1 hour) using a vacuum dryer was 50% by mass.

The solid content of the obtained carboxyl group-containing polyurethane solution had an acid value of 43mgKOH/g and a weight-average molecular weight of 2.0X 10⁴。

The obtained polyurethane has a structural unit represented by the following formula (24).

In the formula, x10+ y8 is 1, x10 is 0.55, and y8 is 0.45. n is₁₃Is a positive integer of about 22 in view of the value of the weight average molecular weight.

Example 17

(silver urethane salt PU-9Ag having 50% of the silver atoms bonded to the carboxyl groups₍₅₀₎Synthesis of (2)

8.00g (containing 2.85mmol of carboxyl groups) of the carboxyl group-containing polyurethane solution obtained in Synthesis example 9 was dissolved in 8.00g of diethylene glycol monoethyl ether (manufactured by Takara Shuzo Co., Ltd.). Subsequently, 0.17g of silver oxide (1.43 mmol of Ag, manufactured by Wako pure chemical industries, Ltd.) was dispersed in 4.00g of diethylene glycol monoethyl ether (manufactured by Takara chemical industries, Ltd.), and the dispersion was added to a polyurethane solution. After stirring at 85 ℃ for 3 hours, it was confirmed that the silver oxide disappeared and became a uniform solution.

The silver salt of the polyurethane thus obtained has a structural unit represented by the following formula (25).

In the formula, x11+ x12+ y9 is 1, x11 is 0.275, x12 is 0.275, and y9 is 0.45. n is₁₃Is a positive integer of about 22 in view of the value of the weight average molecular weight.

< conductive pattern formation 1 >

As the silver particles, AgC239 (Flat shape, D) manufactured by Futian Metal foil powder industries, Ltd₅₀2.3 μm and 0.67 μm thick) in the proportions (parts by mass [ g ]) indicated in table 1]) Then, the resultant was mixed with a rotation-revolution mixer あわとり terang (manufactured by Kabushiki Kaisha シンキー) at normal temperature and pressure (rotation at 600rpm and revolution at 1200rpm was carried out for 3 times for 3 minutes) to prepare 10g of an electrically conductive pasteA paste (composition for forming a conductive pattern). The solvent (dispersion medium) used was Ethyl Carbitol Acetate (ECA) manufactured by ダイセル and Ethyl Carbitol (EC) manufactured by ダイセル. The obtained conductive paste was printed on a polyimide film (product name カプトン (registered trademark) 150EN-C, manufactured by Chinese imperial レ & デュポン, Inc.) by screen printing in a square pattern of 2cm × 2cm with a film thickness of 10 μm or more. After the ink pattern was formed, the conductive pattern was formed by performing thermal firing at 140 ℃ in air using a dryer VO-420 (manufactured by アドバンテック corporation) for the time shown in table 1.

< evaluation of Performance 1 >

(1) Volume resistivity

After the film thickness of the conductive pattern was measured by a micrometer, the surface resistance of the conductive pattern was measured by a resistivity meter ロレスタ GP (manufactured by mitsubishi chemical アナリテック, ltd.) by a 4-terminal method. The measurement mode and the use terminal use the ESP mode. The volume resistivity of the thin film was determined by multiplying the obtained film thickness by the surface resistance. The results are shown in table 1.

As shown in Table 1, in the same baking time and the use of carboxyl group polyurethane, the use of carboxyl group polyurethane with all or a part of the carboxyl group is a metal salt (silver salt or copper salt) with the evaluation of examples 1 ~ 19 and not changed into a metal salt with carboxyl group polyurethane compared with the comparative evaluation of examples 1 ~ 11 reduce the volume resistivity. In addition, it is found that when a part of the carboxyl groups is changed to a metal salt, the volume resistivity decreases as the proportion of the part changed to the metal salt increases. From this, it is understood that the conductive paste using the urethane having a carboxyl group in which all or a part of the carboxyl groups in the examples are changed to a metal salt can improve the conductivity of the conductive pattern with a lower sintering energy than the conductive paste using the urethane having a carboxyl group which is not changed to a metal salt. In the examples, the metal atoms in the metal (silver or copper) salt of the polyurethane as the binder resin were present in a larger amount as compared with the comparative examples, but the amount was 0.3 parts by mass or less per 100 parts by mass of the metal particles and was a trace amount, and therefore the influence on the change in the conductivity was almost negligible.

(2) Adhesion Property

In addition to the volume resistivity, the characteristics required for the conductive pattern include adhesion to the substrate. Therefore, the adhesion between the conductive pattern and the base material was evaluated by the following method.

The conductive pattern was drawn into 11 cuts at 1mm intervals using a cutter knife and a cross guide (cross cut guide) CCJ-1 (manufactured by コーテック corporation), and then further drawn out 11 cuts in a 90 ° direction to form 100 1mm square grids. Cellophane adhesive tape was adhered to the cut printed surface, and the cellophane adhesive tape was rubbed to adhere the tape to the coating film. And (3) after the tape is attached for 1-2 minutes, holding the end of the tape, keeping a right angle with the printing surface, and instantly peeling off the tape. The number of the peeled lattices was set as checkerboard peeling. The results are shown in table 1.

As shown in table 1, even when all or part of the carboxyl groups in the polyurethane having carboxyl groups were changed to metal salts (silver salts or copper salts), the chequer peeling was 0, and thus it was found that the adhesion was maintained. From these results, it is understood that the conductive paste using the polyurethane having a carboxyl group in which all or a part of the carboxyl groups in the examples are changed to a metal salt has good volume resistivity and adhesiveness, and also has 2 properties required for a conductive pattern.

[ Table 1]

< formation of conductive pattern 2/evaluation of Property 2 >

Next, a conductive paste was prepared in which the sum of the amount of silver derived from the silver salt and the amount of silver derived from the particles was constant, and the performance was evaluated. The same methods as those for the conductive pattern formation 1 and the performance evaluation 1 were used for the conductive pattern formation and the performance evaluation, and further the results of firing at 120 ℃ and 170 ℃ were added.

As shown in Table 2, it is understood that in the case where the firing conditions are the same as the urethane skeleton, the volume resistivity of the samples of the examples 1 to 21 in which all or a part of the carboxyl groups are silver salts is reduced without impairing the adhesion as compared with the samples of the comparative examples 1 to 18 in which the carboxyl groups are not silver salts. Further, as shown in examples 1 to 9 and comparative examples 1 to 6, the increase in the ratio of the carboxysilvering decreases the volume resistivity, and thus it was confirmed again that the improvement in the conductivity is derived from the silver salt portion. In this way, even when the amount of silver derived from the silver salt and the amount of silver derived from the particles were made constant, the same results as the above performance evaluation were obtained, and it was found that the improvement in conductivity was not caused only by the increase in the amount of silver in the paste.

[ Table 2]

< formation of conductive pattern 3/evaluation of Property 3 >

Next, a conductive paste using silver particles other than AgC239 was prepared. The same methods as those for the conductive pattern formation 1 and the performance evaluation 1 were used for the conductive pattern formation and the performance evaluation. The newly used silver particles were AgC-A (Flat shape, D) manufactured by Futian Metal foil powder industries, Ltd₅₀3.1 μm, thickness 0.90 μm) and AgC-201Z (flat shape, D)₅₀2.6 μm, thickness 0.76 μm).

As shown in Table 3, it is understood that in the case where the firing conditions are the same as the urethane skeleton, the volume resistivity of the samples of the examples 1 to 12 in which all or a part of the carboxyl groups are silver salts is reduced without impairing the adhesion as compared with the samples of the comparative examples 1 to 12 in which the carboxyl groups are not silver salts. As described above, even when silver particles other than AgC239 are used, the same results as those of the above performance evaluation can be obtained, and therefore the effect of improving the conductivity is not limited to the case of using specific particles, and the polyurethane silver salt of the present invention can be applied to a wide range.

[ Table 3]

< conductive pattern formation 4 composition for conductive pattern formation using silver nanoparticles >

Using DF-AT-5100 (spherical, 40nm average 1-order particle size) manufactured by DOWA エレクトロニクス co., ltd., as silver particles, and mixing the components and blending ratios (parts by mass [ g ]) shown in table 4 using a rotation-revolution mixer あわとり teran (manufactured by corporation, シンキー) AT normal temperature and pressure (rotation 600rpm and revolution 1200rpm for 3 times and 3 minutes), 10g of a conductive paste (composition for forming a conductive pattern) was prepared. The solvent used was Ethyl Carbitol Acetate (ECA) manufactured by ダイセル K.K., Ethyl Carbitol (EC) manufactured by ダイセル K.K., and テルソルブ MTPH manufactured by テルペン K.K., Japan. The obtained conductive paste was printed on an alkali-free glass (product name: イーグル XG, manufactured by コーニング Co.) by screen printing so as to form a square pattern of 2cm × 2cm having a thickness of about 1 μm. After the ink pattern was formed, the resultant was thermally baked at 200 ℃ for 1 hour under air using a dryer VO-420 (manufactured by アドバンテック corporation), thereby forming a conductive pattern.

< evaluation of Performance 4 >

(1) Volume resistivity

The thickness of the conductive pattern was measured by a stylus type surface texture measuring instrument DEKTAK-6M (manufactured by Bruker Nano). The surface resistance of the conductive pattern was measured in a measurement mode using a resistivity meter ロレスタ GP (manufactured by mitsubishi chemical アナリテック, ltd.) by a 4-terminal method and in an ESP mode using a terminal. The volume resistivity of the thin film was determined by multiplying the obtained film thickness by the surface resistance. The results are shown in table 4.

(2) Adhesion Property

The evaluation was performed by the same method as in the above performance evaluation 1. The results are shown in table 4.

As shown in table 4, when the firing conditions and the urethane skeleton were the same, the volume resistivity was lower in the examples than in the comparative examples without impairing the adhesion, as in the above-described evaluation results. From the results, it is shown that the silver urethane salt of the present invention exerts an effect of improving the conductivity not only when combined with the micron-sized silver particles but also when combined with the nano-sized silver particles.

[ Table 4]

< conductive pattern formation 5 composition for conductive pattern formation using silver nanowires >

Silver nanowires were used as the conductive components, and each component and the blending ratio (parts by mass [ g ]) shown in table 5 were mixed at normal temperature and pressure using a rotation-revolution mixer あわとり teran (manufactured by corporation シンキー) (rotation 600rpm and revolution 1200rpm were performed 3 times for 3 minutes), thereby preparing 10g of a conductive paste (composition for forming a conductive pattern). Silver nanowires (average length 20 μm, average diameter 35nm) synthesized by the polyol method were used as silver nanowires, and terpineol C and テルソルブ MTPH (both manufactured by テルペン chemical Co., Ltd.) were used as solvents. Further, although printing and firing were possible using only polyurethane and a silver urethane salt as the binder resin, polyvinylpyrrolidone K-90 (manufactured by BASF) was used in combination in order to maintain the pattern shape after firing more satisfactorily. The obtained conductive paste was printed on a PET film (ルミラー (registered trademark) 125T60, manufactured by imperial レ (ltd)) by screen printing in a square pattern of 2cm × 2 cm. After the ink pattern was formed, the conductive pattern was formed by performing thermal firing at a temperature shown in table 1 for 1 hour under air using a dryer VO-420 (manufactured by アドバンテック corporation).

< evaluation of Performance 5 >

Silver nanowires are used as a material for a transparent conductive film for a touch panel, and since a value of surface resistance is important in comparison with volume resistivity in evaluation of the transparent conductive film, only surface resistance is evaluated. The measuring apparatus was a resistivity meter ロレスタ GP (manufactured by mitsubishi chemical アナリテック, ltd.) based on the 4-terminal method, and the ESP mode was used for the measurement mode and the use terminal. The results are shown in table 5.

As shown in table 5, it is understood that when the firing conditions and the urethane skeleton are the same, the surface resistance of the example evaluation examples is lower than that of the comparative evaluation examples, similarly to the above-described evaluation results. From the results, it was revealed that the silver urethane salt of the present invention exerts an effect of improving conductivity even when combined with silver nanowires.

[ Table 5]

Claims (9)

1. A binder resin for a conductive composition, which comprises a polymer having a structure represented by formula (COO) in its polymer skeleton_nA polyurethane having a metal carboxylate moiety represented by M, wherein M is silver, n is 1,

the polyurethane comprises, as a structural unit, a urethane bond unit formed from (a1) a polyisocyanate compound and (a2) a dihydroxy compound having a carboxyl group.

2. The binder resin for conductive compositions as claimed in claim 1, wherein said dihydroxy compound having a carboxyl group (a2) is at least one of 2, 2-dimethylolpropionic acid and 2, 2-dimethylolbutyric acid.

3. The binder resin for conductive compositions according to claim 1, wherein the polyisocyanate compound (a1) is an alicyclic polyisocyanate.

4. The binder resin for conductive compositions according to claim 3, wherein the alicyclic polyisocyanate is isophorone diisocyanate (IPDI) or bis- (4-isocyanatocyclohexyl) methane (hydrogenated MDI).

5. A composition for forming a conductive pattern, comprising:

the binder resin (A) for conductive compositions according to claim 1;

a conductive material (B); and

a solvent (C) for dissolving the binder resin (A) for the conductive composition.

6. The composition for forming a conductive pattern according to claim 5, wherein the conductive material (B) is metal particles (B1), the proportion of the metal particles (B1) is 20 to 95% by mass, the content of the solvent (C) dissolving the binder resin for a conductive composition is 5 to 80% by mass, and the binder resin (A) for a conductive composition is 1 to 15 parts by mass with respect to 100 parts by mass of the metal particles (B1), with respect to the entire composition for forming a conductive pattern.

7. The composition for forming a conductive pattern according to claim 5, wherein the conductive material (B) is a metal nanowire and/or a metal nanotube (B2), the proportion of the metal nanowire and/or the metal nanotube (B2) is 0.01 to 10% by mass relative to the entire composition for forming a conductive pattern, the content of the solvent (C) for dissolving the binder resin for a conductive composition is 90% by mass or more, and the binder resin (A) for a conductive composition is 10 to 400 parts by mass relative to 100 parts by mass of the metal nanowire and/or the metal nanotube (B2).

8. The composition for forming a conductive pattern according to claim 5, wherein the metal constituting the conductive material (B) is any one of silver and copper.

9. A polyurethane comprising at least one of the structural units represented by the following formula (1),

Images