TW201630861A - Conductive ink and method for manufacturing conductive layer - Google Patents

Abstract

A conductive ink is provided. The conductive ink includes 2,2,6,6-tetramethyl-3,5-heptanedionato silver(I) and an amine-based compound, wherein based on the total weight of the conductive ink, the content of 2,2,6,6-tetramethyl-3,5-heptanedionato silver(I) is 9 wt% to 33 wt%, the content of the amine-based compound is 5 wt% to 74 wt%.

Description

Conductive ink and method for producing conductive layer

The present invention relates to a conductive ink and a method of producing a conductive layer, and more particularly to a conductive ink containing an organometallic complex and a method of producing a conductive layer using the conductive ink.

In order to simplify the complicated steps of fabricating conductive lines via lithography, direct printing of conductive ink onto substrates to form conductive traces has become one of the current research directions. In general, conductive inks containing a metal as a main component are classified into two types: a metal nanoparticle type and an organic metal type, wherein the metal nanoparticle has a high surface area to volume ratio, whereby although it has a large activity, However, it is prone to spontaneous agglomeration to reduce the surface energy. As a result, the metal nanoparticles are prone to agglomeration and precipitation during preparation, storage or transportation, resulting in poor ink stability. Therefore, many studies have gradually evolved toward conductive metals of the organometallic type.

The invention provides a conductive ink which has good stability, simple preparation method and low preparation cost.

The present invention further provides a method of producing a conductive layer which can form a conductive layer having good conductivity under mild heat treatment conditions.

The conductive ink of the present invention comprises (2,2,6,6-tetramethyl-3,5-heptanedione acid) silver (I) and an amine compound, wherein the total weight of the conductive ink is (2, The content of silver (I) of 2,6,6-tetramethyl-3,5-heptanedione acid is from 9 wt% to 33 wt%, and the content of the amine compound is from 5 wt% to 74 wt%.

In an embodiment of the invention, the conductive ink further includes a solvent, wherein the solvent is contained in an amount of 28% by weight to 60% by weight based on the total weight of the conductive ink.

In one embodiment of the present invention, the amine compound is a primary amine compound, a diamine compound or a triamine compound.

In one embodiment of the present invention, the above amine compound is hexylamine, n-octylamine, benzylamine, ethylenediamine, 1,2-propylenediamine, 1,3-propanediamine, tetramethylethyl Diamine or diethylenetriamine.

In one embodiment of the invention, the solvent is an alcohol solvent.

In one embodiment of the invention, the solvent is methanol, ethanol, isopropanol, n-butanol, isobutanol, secondary butanol, tertiary butanol, 1-hexanol or 2-hexanol or combination.

In an embodiment of the invention, the conductive ink further includes an additive, wherein the additive is contained in an amount of from 3 wt% to 14 wt%, based on the total weight of the conductive ink.

The method for producing a conductive layer of the present invention includes the following steps. First, a substrate is provided. Next, the aforementioned conductive ink is supplied onto the substrate. Thereafter, the conductive ink supplied onto the substrate is subjected to heat treatment.

In an embodiment of the invention, the substrate is a rigid substrate or a flexible substrate.

In an embodiment of the present invention, a method of providing a conductive ink to a substrate includes an inkjet printing method, a gravure printing method, a letterpress printing method, an offset printing method, a screen printing method, or a wire bar coating method.

In an embodiment of the invention, the heat treatment has a temperature between 100 ° C and 200 ° C and a time between 10 minutes and 60 minutes.

Based on the above, the conductive ink of the present invention has good properties by including silver (I) having a specific ratio of (2,2,6,6-tetramethyl-3,5-heptanedione acid) and an amine compound. A stable homogeneous solution whereby a conductive layer having good electrical conductivity is formed by printing or coating and under low temperature and short heating conditions.

The above described features and advantages of the present invention will be more apparent from the following description.

In this paper, the range represented by "a value to another value" is one. A summary representation of all numerical values in the range is omitted in the specification. Therefore, the recitation of a particular range of values is intended to include any value in the range of values and the range of values defined by any value in the range of values, as in the specification. The scope is the same.

In order to prepare a conductive ink which has good stability and is simple in preparation method and low in preparation cost, the present invention proposes a conductive ink which can attain the above advantages. Hereinafter, the specific embodiments are described as examples in which the present invention can be implemented.

One embodiment of the present invention provides a conductive ink comprising (2,2,6,6-tetramethyl-3,5-heptanedione acid) silver (I) ((2,2,6,6-tetramethyl) -3,5-heptanedionato)silver(I), Ag(tmhd)) and an amine compound. Hereinafter, the various components described above will be described in detail.

In the conductive ink, (2,2,6,6-tetramethyl-3,5-heptanedione acid) silver (I) acts as a precursor of silver. In detail, when energy (for example, thermal energy or light energy) is supplied to the conductive ink, the positive monovalent in (2,2,6,6-tetramethyl-3,5-heptanedione acid) silver (I) The silver ions are reduced to metallic silver. In one embodiment, the (2,2,6,6-tetramethyl-3,5-heptanedione acid) silver (I) is present in an amount of from 9 wt% to 33 wt%, based on the total weight of the conductive ink.

Further, (2,2,6,6-tetramethyl-3,5-heptanedione acid) silver (I) can be obtained by silver acid acid and 2,2,6,6-tetramethyl-3. 5-heptanedione (2,2,6,6-tetramethyl-3,5-heptanedione, tmhd) obtained by reaction in the presence of triethylamine and a solvent, or (2, 2, 6, 6- Commercially available products can be used as the silver (I) tetramethyl-3,5-heptanedione acid.

In the conductive ink, the amine compound reacts with (2,2,6,6-tetramethyl-3,5-heptanedionone) silver (I) to form a silver amine complex to further stabilize the silver ion. And increase the solubility, thereby making the conductive ink have good stability. In one embodiment, the amine compound is present in an amount of from 5 wt% to 74 wt%, based on the total weight of the conductive ink.

Specifically, examples of the amine compound include, but are not limited to, a primary amine compound such as hexylamine, n-octylamine or benzylamine; ethylenediamine, 1,2-propylenediamine, 1,3-propanediene a diamine compound such as an amine or tetramethylethylenediamine; or a triamine compound such as diethylenetriamine. In one embodiment, the amine compound is preferably a first amine compound or a diamine compound.

In addition, the conductive ink may further include a solvent within a range that does not impair the effect of the conductive ink of the present invention. In detail, the solvent is used to dissolve (2,2,6,6-tetramethyl-3,5-heptanedione acid) silver (I) and an amine compound to form a homogeneous conductive ink. In one embodiment, the solvent is, for example, an alcohol solvent. Specifically, examples of the solvent include, but are not limited to, methanol, ethanol, isopropanol, n-butanol, isobutanol, secondary butanol, tertiary butanol, 1-hexanol or 2-hexanol. In one embodiment, the solvent is present in an amount of from 28% by weight to 60% by weight based on the total weight of the conductive ink.

Further, the solvents listed above may be used singly or in combination of two or more kinds. That is, the solvent system can be adjusted to the ink characteristics required for different applications. For example, the conductive ink of the present invention can be adapted to obtain suitable properties by adjusting the solvent system.

In addition, the conductive ink may further include an additive for adjusting the adhesion of the conductive ink, the surface sheet, within a range of effects that do not impair the conductive ink of the present invention. Force or viscosity. In one embodiment, the additive comprises ethyl cellulose, carboxymethyl cellulose, a bismaleimide resin or a decane coupling agent. However, the invention is not limited to the disclosed content. Further, in an embodiment, the content of the additive is from 3 wt% to 14 wt%, based on the total weight of the conductive ink.

In addition, the conductive ink of the present invention has a simple preparation method and a low production cost. In detail, in one embodiment, a method of preparing a conductive ink includes the following steps. First, an amine compound is mixed with (2,2,6,6-tetramethyl-3,5-heptanedionone) silver (I) in an ice bath environment and stirred for 1 hour to 2 hours. Thereafter, the resulting solution was subjected to a filtration step to remove trace particles. In addition, in the case where the conductive ink further includes a solvent, the method for preparing the conductive ink further comprises: uniformly mixing the amine compound with the solvent before performing the filtering step, and then (2, 2, 6, 6-tetramethyl- 3,5-Heptanedione acid) Silver (I) was added. In addition, in the case where the conductive ink further includes an additive, the method of preparing the conductive ink further includes adding an additive before performing the filtering step.

It is worth noting that, as described above, the conductive ink of the present invention is a homogeneous solution having good stability, and (2,2,6,6-tetramethyl-3,5-heptanedione acid) is used. Silver (I) acts as a precursor to silver, whereby the conductive ink of the present invention is quite suitable for forming a conductive layer having good electrical quality by printing or coating. For example, in an electronic device, the conductive layer can function as a wire. Hereinafter, a method of manufacturing a conductive layer using a conductive ink will be described in detail with reference to an embodiment, and as an example, the present invention can be carried out.

Another embodiment of the present invention provides a method of manufacturing a conductive layer, comprising the following steps. First, a substrate is provided. In the present embodiment, the substrate is for example It is a rigid substrate including a glass substrate, a rigid plastic substrate, a metal substrate or a ceramic substrate, or a polyimide substrate, a polyethylene terephthalate substrate, a polycarbonate substrate, a polypropylene substrate, a polyethylene substrate, A flexible substrate such as a polystyrene substrate or a thin metal or alloy substrate.

Next, any of the conductive inks described above are supplied onto the substrate. In detail, the method of performing the above steps is, for example, a printing method or a coating method. The printing method includes an inkjet printing method, a gravure printing method, a letterpress printing method, an offset printing method, or a screen printing method, and the coating method includes a wire bar coating method.

Thereafter, the conductive ink supplied onto the substrate is subjected to heat treatment. In detail, the heat treatment may cause the solvent in the conductive ink to be completely removed, and then solidified to form a conductive layer. In one embodiment, the temperature of the heat treatment is, for example, between 100 ° C and 200 ° C, and the heating time is, for example, between 10 minutes and 60 minutes. In addition, in one embodiment, the sheet resistance of the conductive layer is, for example, between 0.45 Ω/sq and 190 Ω/sq, which means that the conductive layer has good electrical conductivity.

In general, nano metal inks need to be sintered at a high temperature of 200 ° C to 300 ° to form a conductive layer with good electrical quality. Therefore, nano metal inks cannot be effectively applied to flexible substrates that cannot withstand high temperatures, resulting in applications. The field is limited. In detail, the polyethylene terephthalate substrate can only withstand temperatures below 120 °C. In view of this, the conductive ink of the present invention can form a conductive layer having good electrical quality at a lower temperature than the conventional nano ink, and thus can have a wider application field.

In addition, the conductive ink further includes, for example, a viscosity modifier or In the case of an additive of a decane coupling agent, the adhesion between the conductive ink and the substrate is increased.

Features of the present invention will be more specifically described below with reference to Embodiment 1 to Embodiment 17. Although the following examples are described, the materials used, the amounts and ratios thereof, the processing details, the processing flow, and the like can be appropriately changed without departing from the scope of the invention. Therefore, the invention should not be construed restrictively by the examples described below.

Information on the materials and equipment used to prepare the conductive layers of Examples 1 to 17 is as follows.

(2,2,6,6-Tetramethyl-3,5-heptanedione acid) Silver (I): It was produced by the production method shown below.

Under a nitrogen atmosphere, 4.2 g of silver nitrate was dissolved in 1.4 ml of acetonitrile and 50 ml of methanol in a three-necked flask. After stirring and mixing well, the temperature was lowered to 0 ° C, and the solution was slowly added to contain 5.5 ml of 2,2,6,6-tetramethyl-3,5-heptanedione, 3.5 ml of triethyl A solution of amine and 50 ml of methanol. Then, after continuously stirring the reaction at 0 ° C for 1 hour, the resulting solution was quickly filtered to obtain a white solid powder. Thereafter, the obtained white solid powder was washed with methanol several times, and dried by vacuum to obtain (2,2,6,6-tetramethyl-3,5-heptanedione acid) in a yield of about 60%. Silver (I).

Double Malay Polyimine Resin (Additive): The trade name is BMI 3000.

Resistivity meter: Model No. Loresta-EP MCP-T360, manufactured by Mitsubishi Chemical Corporation.

Example 1 Preparation of conductive ink

First, 0.7 g of n-octylamine was uniformly mixed with 1 g of isopropyl alcohol in an ice bath environment (0 ° C to 15 ° C). Next, 1 g of (2,2,6,6-tetramethyl-3,5-heptanedionone) silver (I) was added to the resulting solution and stirred for 1 hour to form a silver amine complex solution. . Thereafter, 0.3 g of ethyl cellulose was added to the silver amine complex solution and stirred well. Next, filtration was carried out with a 0.45 μm filter membrane to obtain a conductive ink of Example 1.

Conductive layer manufacturing

First, the conductive ink of Example 1 was coated on a polyimide substrate with a wire bar (Model No. RDS No. 26). Next, heat treatment was performed at 100 ° C for 30 minutes to obtain a conductive layer of Example 1.

Example 2 to Example 17

The conductive inks of Examples 2 to 17 were prepared by the same preparation procedure as in Example 1, except that the kinds and amounts of the respective components shown in Table 1 below were used. Next, the conductive layers of Examples 2 to 17 were produced in the same manufacturing procedure as in Example 1, except that the types of substrates shown in Table 1 and the heating temperatures and times shown in Table 1 were used.

Example 18 to Example 19

The difference between Example 18 to Example 19 and Example 1 is that the solvent is not used in the preparation of the conductive ink, and the amine compound and (2,2,6,6-tetramethyl-3,5-heptane are directly used. The diketo acid) silver (I) was mixed and stirred, and the types and amounts of the respective components are shown in Table 1 below. Next, the conductive layers of Examples 18 to 19 were produced in the same manufacturing procedure as in Example 1, except that the types of substrates shown in Table 1 and the heating temperatures and times shown in Table 1 were used.

Thereafter, the sheet resistances of the conductive layers of Examples 1 to 19 were respectively measured by a four-point probe method using a resistivity meter, and the measurement results are shown in Table 2.

As is apparent from the above Tables 1 and 2, the conductive layers of Examples 1 to 19 which were obtained by heat treatment under the conditions of a heating temperature of less than 200 ° C and a heating time of 60 minutes or less had good electrical conductivity. . Further, as is apparent from the above Tables 1 and 2, in the third embodiment, the conductive ink of the present invention can form a conductive layer having good conductivity on the polyethylene terephthalate substrate, which means the conductive ink of the present invention. The conductive layer having good electrical quality can be formed by low-temperature heat treatment for several minutes, whereby the field in which the conductive ink can be applied can be improved.

Although the invention has been disclosed above in the embodiments, it is not intended to be limiting The scope of the present invention is defined by the scope of the appended claims, and the scope of the present invention is defined by the scope of the appended claims. Prevail.

Claims (11)

A conductive ink comprising: (2,2,6,6-tetramethyl-3,5-heptanedione acid) silver (I); and an amine compound; wherein the total weight of the conductive ink is , (2,2,6,6-tetramethyl-3,5-heptanedione acid) silver (I) is contained in an amount of 9 wt% to 33 wt%, and the amine compound is contained in an amount of 5 wt% to 74 wt% . The conductive ink according to claim 1, further comprising a solvent, wherein the solvent is contained in an amount of 28% by weight to 60% by weight based on the total weight of the conductive ink. The conductive ink according to claim 1, wherein the amine compound is a primary amine compound, a diamine compound or a triamine compound. The conductive ink according to claim 1, wherein the amine compound is hexylamine, n-octylamine, benzylamine, ethylenediamine, 1,2-propylenediamine, 1,3-propanediamine. , tetramethylethylenediamine or diethylenetriamine. The conductive ink of claim 2, wherein the solvent is an alcohol solvent. The conductive ink according to claim 2, wherein the solvent is methanol, ethanol, isopropanol, n-butanol, isobutanol, secondary butanol, tertiary butanol, 1-hexanol, 2 -hexanol or a combination thereof. The conductive ink according to claim 1 or 2, further comprising an additive, wherein the additive has a content of 3 based on the total weight of the conductive ink Wt% to 14wt%. A method of manufacturing a conductive layer, comprising: providing a substrate; providing a conductive ink to the substrate, wherein the conductive ink is a conductive ink according to claim 1; and providing a substrate to the substrate The conductive ink on the upper surface is subjected to heat treatment. The method of producing a conductive layer according to claim 8, wherein the substrate is a rigid substrate or a flexible substrate. The method for producing a conductive layer according to claim 8, wherein the method of providing the conductive ink to the substrate comprises an inkjet printing method, a gravure printing method, a letterpress printing method, an offset printing method, a screen printing method Printing method or wire bar coating method. The method for producing a conductive layer according to claim 8, wherein the temperature of the heat treatment is between 100 ° C and 200 ° C, and the heat treatment time is between 10 minutes and 60 minutes.