JP2014118483A - Ink composition, transparent conductive film and electronic component - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ink composition good in storage stability and capable of improving productivity of a transparent conductive film, and to provide the transparent conductive film and an electronic component.SOLUTION: The ink composition contains (A) a polyethylene dioxythiophene/polystyrene sulfonate solution, (B) an epoxysilane compound and (C1) dimethylamino ethanol and has an acidity of 2.55 to 3.00. The ink composition also contains (A) a polyethylene dioxythiophene/polystyrene sulfonate solution, (B) an epoxysilane compound and (C2) an aminosilane compound and has the acidity of 2.75 to 4.15.

Description

  The present invention relates to an ink composition, a transparent conductive film using the same, and an electronic component.

  Transparent conductive films are used in fields such as liquid crystal displays, electroluminescence displays, plasma displays, electrochromic displays, solar cells, and touch panels. Examples of the material for the transparent conductive film include conductive inorganic materials such as ITO (indium-tin oxide), and conductive organic materials such as polyethylenedioxythiophene (PEDOT): polystyrene sulfonic acid (PSS).

  As a transparent conductive film using a conductive organic material, one using an ink composition containing a PEDOT: PSS aqueous solution and an epoxysilane compound has been proposed (for example, see Patent Document 1). In such an ink composition, by including an epoxy silane compound as a coupling agent, the ring-opening addition reaction between the epoxy group of the epoxy silane compound and the sulfonic acid group of PSS after application of the ink composition and the alkoxy silane Hydrolysis reaction and condensation reaction proceed. As a result, a three-dimensional network (crosslink) is formed between the molecular chains of the epoxysilane compound and PEDOT: PSS via a crosslink, so that the transparent conductive material having high mechanical strength with excellent wear resistance. A membrane can be realized.

JP 2009-508341 A

  However, in the ink composition described in Patent Document 1, after preparing an ink composition by mixing an aqueous solution of PEDOT: PSS and an epoxysilane compound, a transparent conductive film using an ink composition that has been allowed to stand overnight or longer is used. When the film is formed, the mechanical strength of the transparent conductive film is extremely deteriorated. For this reason, there was a problem that the ink composition could not be stored and the productivity of the transparent conductive film was affected.

  This invention is made | formed in view of this point, and it aims at providing the ink composition which has favorable storage stability and can improve the productivity of a transparent conductive film.

  The ink composition of the present invention comprises (A) a polyethylenedioxythiophene / polystyrenesulfonic acid aqueous solution, (B) an epoxysilane compound, and (C1) dimethylaminoethanol, and has an acidity of 2.75 or more and 4 .15 or less.

  According to this ink composition, dimethylaminoethanol as an alkaline component having a hydrophilic amino group neutralizes the acid component of the strong acid polyethylenedioxythiophene / polystyrenesulfonic acid aqueous solution. The ring-opening addition reaction between the epoxysilane compound and polyethylenedioxythiophene / polystyrenesulfonic acid in the state, and the hydrolysis reaction and condensation reaction of the epoxysilane compound can be prevented. Thereby, since the storage stability of the ink composition is improved, the productivity of the transparent conductive film can be improved.

  In the ink composition of the present invention, the weight ratio of the (B) epoxysilane compound to the (C1) dimethylaminoethanol is in the range of (B) component: (C1) component = 80: 20 to 85:15. It is preferable that

  The ink composition of the present invention contains (A) an aqueous polyethylenedioxythiophene / polystyrene sulfonic acid solution, (B) an epoxysilane compound, and (C2) an aminosilane compound, and has an acidity of 2.55 or more and 3. It is characterized by being 00 or less.

  According to this ink composition, the acid component based on the polyethylenedioxythiophene / polystyrenesulfonic acid aqueous solution, which is a strong acid, is neutralized by the aminosilane compound as an alkali component having a hydrophilic amino group. The ring-opening addition reaction between the epoxysilane compound and polyethylenedioxythiophene / polystyrenesulfonic acid in the state, and the hydrolysis reaction and condensation reaction of the epoxysilane compound can be prevented. Thereby, since the storage stability of the ink composition is improved, the productivity of the transparent conductive film can be improved. Moreover, since a cross-linking bond is also formed between the aminosilane compound and the epoxysilane compound, a transparent conductive film excellent in sheet resistance can be obtained.

  In the ink composition of the present invention, the weight ratio of the (B) epoxysilane compound to the (C2) aminosilane compound is within the range of (B) component: (C2) component = 67: 33 to 83:17. Preferably there is.

  In the ink composition of the present invention, the (C2) aminosilane compound is preferably 3-aminopropyltriethoxysilane.

  In the ink composition of the present invention, the (B) epoxysilane compound is preferably 3-glycidoxypropyltrimethoxysilane.

  The transparent conductive film of the present invention is obtained using the above ink composition.

  An electronic component according to the present invention includes the transparent conductive film.

  According to the present invention, it is possible to realize an ink composition that has good storage stability and can improve the productivity of a transparent conductive film.

It is explanatory drawing of the reaction mechanism regarding formation of the crosslink in the ink composition which concerns on this Embodiment. It is a flowchart which shows the outline of the manufacturing process of the transparent conductive film which concerns on this Embodiment.

  Hereinafter, an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

(Ink composition)
First, the outline of the ink composition according to the present invention will be described. The ink composition according to the present invention contains (A) a polyethylenedioxythiophene (PEDOT): polystyrenesulfonic acid (PSS) aqueous solution, (B) an epoxysilane compound, and (C) an amine compound. This ink composition is used for forming a transparent conductive film used for various electronic components. A transparent conductive film is obtained by baking (baking) the ink composition apply | coated on the base material. Since a three-dimensional network is formed between PEDOT: PSS and the epoxysilane compound via a crosslink during this baking, a transparent conductive film having high mechanical strength can be obtained.

  FIG. 1 is an explanatory diagram of a reaction mechanism relating to the formation of a cross-linked bond in the ink composition according to the present invention. As shown in FIG. 1, in the ink composition according to the present invention, when the ink composition applied on the substrate is baked, the sulfonic acid group in the molecule of PEDOT: PSS and the epoxysilane compound are not separated. Then, the ring-opening addition reaction proceeds to bond the PEDOT: PSS molecule and the epoxysilane compound. This PEDOT: PSS-bonded epoxysilane compound undergoes a hydrolysis reaction of an alkoxysilyl group and a condensation reaction between a hydroxyl group generated by this hydrolysis reaction and an alkoxy group of another epoxysilane compound, via a siloxane bond. Two molecules of epoxy silane compounds are bonded. Then, as a result of repeating these ring-opening addition reaction, hydrolysis reaction and condensation reaction, a three-dimensional network (crosslink) is formed between PEDOT: PSS and the epoxysilane compound via a crosslink by a siloxane bond. Is done.

  In the ink composition containing the PEDOT: PSS aqueous solution and the epoxysilane compound, the inventors of the present invention have remarkably improved physical properties of the transparent conductive film obtained by using the ink composition when the ink composition is allowed to stand for a certain period of time. Focused on the decline. The inventors of the present invention have the reason that the physical properties of the transparent conductive film are reduced because protons based on the acid component of the PEDOT: PSS aqueous solution, which is a strong acid having a pH of 1 to 2, function as a catalyst and store the ink composition at room temperature. In this state, the ring-opening addition reaction between PEDOT: PSS and the epoxysilane compound, and the hydrolysis reaction and condensation reaction of the epoxysilane compound proceed rapidly. I found out that a dimensional network is not formed. Furthermore, the present inventors have prevented the generation of unnecessary residues that lower the conductivity of the transparent conductive film by adding (C) amine compound as an alkali component having a hydrophilic amino group to the ink composition. However, they found that these reactions can be suppressed, and completed the present invention based on this finding.

  That is, the gist of the present invention includes (A) a polyethylenedioxythiophene: polystyrene sulfonic acid aqueous solution, (B) an epoxysilane compound, and (C) an amine compound, and has an acidity within a predetermined range. It is a thing. As a result, the acid component based on the PEDOT: PSS aqueous solution, which is a strong acid, is neutralized by the amine compound as an alkali component having a hydrophilic amino group, so that the epoxy in a state where the ink composition is stored at room temperature. The ring-opening addition reaction between a silane compound and PEDOT: PSS, and the hydrolysis reaction and condensation reaction of an epoxy silane compound can be prevented. As a result, the storage stability of the ink composition is improved, and the productivity of the transparent conductive film can be improved. The acidity is a value indicating the degree of strength as an acid, and is usually represented by a hydrogen ion exponent pH.

Hereinafter, each component will be described in detail.
(A) PEDOT: PSS aqueous solution The PEDOT: PSS aqueous solution is not particularly limited as long as it exhibits the effects of the present invention. Moreover, as this PEDOT: PSS aqueous solution, you may use a commercial item as it is. As a commercial item of PEDOT: PSS aqueous solution, Clevios (trademark: made by Heraeus) P, Clevios PH500, Clevios PH1000 etc. are mentioned, for example.

(B) Epoxy silane compound As long as an epoxy silane compound forms a siloxane bond with PEDOT: PSS through an epoxy group-mediated cycloaddition reaction, hydrolysis reaction, and condensation reaction, the present invention. Various epoxy silane compounds can be used as long as the above effects are exhibited. As the epoxysilane compound, for example, a silane coupling agent such as dialkoxysilane having an epoxy group or trialkoxysilane having an epoxy group can be used. As dialkoxysilane containing an epoxy group, for example, 3-glycidoxypropylmethyldiethoxysilane can be used. Examples of the triepoxysilane containing an epoxy group include 3-glycidoxypropyltrimethoxysilane, 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, and 2- (3,4-epoxycyclohexyl). Examples thereof include ethyltriethoxysilane.

  In the ink composition of the present invention, it is preferable that the (B) epoxysilane compound is 3-glycidoxypropyltrimethoxysilane. Since this 3-glycidoxypropyltrimethoxysilane has an epoxy group at the terminal, the reactivity of the ring-opening addition reaction is high, and since the substituent on silicon is a methoxy group, hydrolysis reaction and The reactivity of the condensation reaction is high. Thereby, since a high-density crosslinked bond can be formed between PEDOT: PSS, a transparent conductive film having high mechanical strength and the like can be formed.

(C) Amine compound In the present invention, the compatibility of the amine compound and the aqueous solution of PEDOT: PSS can be ensured by using an amine compound having a hydrophilic amino group, so that the ink composition is adjusted to an arbitrary acidity. It becomes possible. As the amine compound, various amine compounds can be used as long as they have compatibility with the PEDOT: PSS aqueous solution and the solvent described later and can adjust the acidity of the ink composition within a predetermined range. Hereinafter, embodiments of the amine compound in the present invention will be described in detail.

(First embodiment)
In the first embodiment of the present invention, (C1) dimethylaminoethanol is used as the amine compound. In the first embodiment, the ink composition has an acidity of 2.75 or more and 4.15 or less. By setting it as this range, since the progress of the crosslinking reaction in the state of the ink composition described above can be suppressed, the storage stability of the ink composition is improved. Moreover, since dimethylaminoethanol has a hydroxyl group in addition to a hydrophilic amino group, the compatibility with a PEDOT: PSS aqueous solution and a solvent described later is improved. Furthermore, since dimethylaminoethanol has low reactivity with the epoxysilane compound, it is possible to prevent gelation of the ink composition, and it is possible to store the ink composition for a long period of time.

  In the first embodiment, the weight ratio of (B) the epoxysilane compound and (C1) dimethylaminoethanol is in the range of (B) component: (C1) component = 80: 20 to 85:15. It is preferable. As a result, the acidity is within the above-described range, and the storage stability of the ink composition is improved.

  In the first embodiment, various amine compounds can be included within the range in which the effect of the present invention is achieved as long as the acidity range is satisfied.

(Second Embodiment)
In the second embodiment of the present invention, (C2) aminosilane compound is used as the amine compound. In the second embodiment, the ink composition has an acidity of 2.55 or more and 3.00 or less. By setting it as this range, since the progress of the crosslinking reaction in the state of the ink composition described above can be suppressed, the storage stability of the ink composition is improved. In the second embodiment, as in the first embodiment, various amine compounds can be included within the range in which the effect of the present invention is achieved as long as the acidity range is satisfied.

  In the second embodiment, the weight ratio of (B) epoxysilane compound to (C2) aminosilane compound is within the range of (B) component: (C2) component = 67: 33 to 83:17. Is preferred. As a result, the acidity is within the above-described range, and the properties of the transparent conductive film obtained from the ink composition are sufficient.

  As the aminosilane compound, for example, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, and 3-aminopropyltripropoxysilane can be used. By using such an aminosilane compound having an alkoxysilyl group, a cross-linking bond can be formed with the epoxysilane compound by hydrolysis reaction and condensation reaction of the alkoxysilyl group. Thereby, it becomes possible to produce a transparent conductive film excellent in mechanical strength and sheet resistance as compared with the case where dimethylaminoethanol is used.

  In the second embodiment, the (C2) aminosilane compound is preferably 3-aminopropyltriethoxysilane. Since this 3-aminopropyltriethoxysilane has a triethoxysilyl group at the terminal, the reactivity of hydrolysis reaction and condensation reaction is moderately high. Thereby, since a high-density cross-linking bond can be formed with the epoxysilane compound, a transparent conductive film having high mechanical strength and the like can be formed.

  Further, as the amine compound, the dimethylaminoethanol according to the first embodiment described above and the aminosilane compound according to the second embodiment may be mixed and used within a range where the effects of the present invention are exhibited.

(D) Other components In the ink composition according to the present invention, a highly viscous compound as an enhancer may be used as long as the effects of the present invention are exhibited. Examples of such highly viscous compounds include dimethyl sulfoxide (DMSO).

(E) Solvent In the ink composition according to the present invention, the properties of the transparent conductive film obtained from the ink composition can be obtained as long as they are compatible with the PEDOT: PSS aqueous solution, the epoxysilane compound, and the amine compound. Various solvents can be included as long as they are satisfied. As the solvent, for example, various alcohols such as isopropanol (IPA) can be used.

  Next, the manufacturing method of the ink composition and transparent conductive film according to the present invention will be described. FIG. 2 is a flowchart showing an outline of the manufacturing process of the ink composition and the transparent conductive film according to the present embodiment.

  As shown in FIG. 2, first, a mixed solution is prepared by adding an epoxysilane compound in an amount equal to the solid content of PEDOT: PSS to a PEDOT: PSS stock solution (an aqueous solution containing only PEDOT: PSS) (step ST1). In this state, the acidity of the mixed solution is a strong acid of about 2.4. Next, dimethylaminoethanol or an aminosilane compound is added to the prepared mixed solution to adjust the acidity to the above range (step ST2).

  Next, an ink composition is prepared by adding an epoxy silane compound, isopropanol as a solvent, dimethyl sulfoxide as an enhancer, and the like to the mixed solution with adjusted acidity (step ST3). Next, the produced ink composition is filtered (step ST4). Next, a polyethylene terephthalate (PET) film or the like is cut into a desired size, and the cut PET film is attached onto a glass wafer to produce a substrate (step ST5).

  Next, an ink composition is formed on the prepared substrate by a spin coat method or the like (step ST6). Next, after pre-baking the deposited ink composition at a predetermined temperature and for a predetermined time (step ST7), a transparent conductive film is produced by performing the main baking for a predetermined temperature and a predetermined time (step ST8).

  Next, examples performed for clarifying the effects of the present invention will be described. The present invention is not limited to the following examples.

  In the following examples, the ink composition according to the above embodiment and the ink composition according to the comparative example were prepared, a transparent conductive film was prepared using the prepared ink composition, and the physical properties were evaluated. The measurement conditions for various physical properties are shown below.

(Measurement of acidity)
The acidity (pH) was measured with a pH meter (trade name: D-51, manufactured by HORIBA, Ltd.). As the standard solution, a standard solution (pH: 1.68, 4.01, 6.86) manufactured by Kanto Chemical Co., Ltd. was used.

(Abrasion resistance evaluation)
The abrasion resistance was evaluated by an abrasion test using a wet swab abrasion tester. This wet swab wear tester is an apparatus that rubs back and forth while pressing a sufficiently wetted swab against the surface of a transparent conductive film under a condition of 30 mm / s while controlling the load to 250 g with a spring balance. After the abrasion test, the transparent conductive film was visually scratched and scratched, and evaluated by the number of rubs when the damage was detected. The evaluation criteria are shown below.
A: 101 times or more B: 51 times or more and 100 times or less C: 26 times or more and 50 times or less D: 2 times or more and 25 times or less E: 1 time or less

(Area resistance value)
The area resistance value (sheet resistance value) of the transparent conductive film was determined by measuring the surface resistance of the transparent conductive film using a four-probe type area resistance meter (LORESTA EP MCP-1360, manufactured by Mitsubishi Chemical Corporation).

(Total light transmittance)
The total light transmittance of the transparent conductive film was measured using a haze meter (trade name: HZ-2, manufactured by Suga Test Instruments Co., Ltd.), and measurement based on JIS-K7361-1 was performed.

((C) Identification of amine compound)
The introduction of the amine compound into the transparent conductive film was confirmed by a photoelectron spectrometer (trade name: ESCA5500, manufactured by ULVAC-PHI). It measured about three arbitrary points of the produced transparent conductive film, and the amine compound in a transparent conductive film was identified by the average value.
Measurement conditions X-ray source: Al Photoemission angle: 45 °

  First, the inventors prepared an ink composition having an acidity adjusted to a predetermined value by changing the content of dimethylaminoethanol for the ink composition according to the first embodiment of the present invention. After the ink composition was allowed to stand for a predetermined period, the abrasion resistance, the sheet resistance value, and the total light transmittance when a transparent conductive film was produced were examined. Hereinafter, the contents investigated by the inventors with reference to Examples 1 to 4 and Comparative Examples 1 to 4 will be described.

<Example 1>
(Preparation of ink composition)
(A) As a PEDOT: PSS aqueous solution, a commercial product (trade name: PH1000, manufactured by Heraeus) having a solid content of 1.1% by weight was used. In 47 parts by weight of this PEDOT: PSS aqueous solution, (B) 3-glycidoxypropyltrimethoxysilane (trade name: Z-6040, manufactured by Toray Dow Corning) as an epoxysilane compound and (C) an amine compound ( C1) An ink composition was prepared by mixing 0.5 parts by weight of dimethylaminoethanol, 5 parts by weight of dimethyl sulfoxide (DMSO) as an enhancer, and 47.5 parts by weight of isopropanol as a solvent. The component (B) and the component (C1) were mixed and used so that the acidity of the ink composition was 2.75. The weight ratio of component (B) and component (C1) and the acidity of the ink composition are shown in Table 1 below.

(Preparation of transparent conductive film)
A PET film cut out in a 70 mm square was pasted on a glass wafer to prepare a substrate. On the PET film of this substrate, an ink composition stored for 0 day (1 hour after preparation) to 21 days was formed by spin coating under conditions of 2000 rpm to 4000 rpm for 10 seconds. Next, the ink composition thus formed was pre-baked at 90 ° C. for 5 minutes, and then subjected to main baking at 120 ° C. for 20 minutes to produce a transparent conductive film. Dimethylaminoethanol was detected from each of the produced transparent conductive films. The prepared transparent conductive film was subjected to abrasion resistance test, area resistance value and total light transmittance measurement. The evaluation results are shown in Table 2 and Table 3 below.

<Example 2>
A transparent conductive film was prepared and evaluated in the same manner as in Example 1 except that the components (B) and (C1) were mixed so that the acidity of the ink composition was 3.00. Dimethylaminoethanol was detected from each of the produced transparent conductive films. The weight ratio of the component (B) and the component (C1) and the acidity of the ink composition are shown in Table 1 below, and the evaluation results are shown in Table 2 and Table 3 below.

<Example 3>
A transparent conductive film was prepared and evaluated in the same manner as in Example 1 except that the components (B) and (C1) were mixed so that the acidity of the ink composition was 3.50. Dimethylaminoethanol was detected from each of the produced transparent conductive films. The weight ratio of the component (B) and the component (C1) and the acidity of the ink composition are shown in Table 1 below, and the evaluation results are shown in Table 2 and Table 3 below.

<Example 4>
A transparent conductive film was prepared and evaluated in the same manner as in Example 1 except that the component (B) and the component (C1) were mixed so that the acidity of the ink composition was 4.15. Dimethylaminoethanol was detected from each of the produced transparent conductive films. The weight ratio of the component (B) and the component (C1) and the acidity of the ink composition are shown in Table 1 below, and the evaluation results are shown in Table 2 and Table 3 below.

<Comparative Example 1>
A transparent conductive film ink composition was prepared in the same manner as in Example 1 except that the component (C1) was not added to the ink composition. The acidity of the ink composition was 2.40. Dimethylaminoethanol was not detected from each of the produced transparent conductive films. The weight ratio of the component (B) and the component (C1) and the acidity of the ink composition are shown in Table 1 below, and the evaluation results are shown in Table 2 and Table 3 below.

<Comparative example 2>
A transparent conductive film was prepared and evaluated in the same manner as in Example 1 except that the components (B) and (C1) were mixed so that the acidity of the ink composition was 2.45. Dimethylaminoethanol was detected from each of the produced transparent conductive films. The weight ratio of the component (B) and the component (C1) and the acidity of the ink composition are shown in Table 1 below, and the evaluation results are shown in Table 2 and Table 3 below.

<Comparative Example 3>
A transparent conductive film was prepared and evaluated in the same manner as in Example 1 except that the components (B) and (C1) were mixed so that the acidity of the ink composition was 2.50. Dimethylaminoethanol was detected from each of the produced transparent conductive films. The weight ratio of the component (B) and the component (C1) and the acidity of the ink composition are shown in Table 1 below, and the evaluation results are shown in Table 2 and Table 3 below.

<Comparative example 4>
A transparent conductive film was prepared and evaluated in the same manner as in Example 1 except that the components (B) and (C1) were mixed so that the acidity of the ink composition was 5.50. Dimethylaminoethanol was detected from each of the produced transparent conductive films. The weight ratio of the component (B) and the component (C1) and the acidity of the ink composition are shown in Table 1 below, and the evaluation results are shown in Table 2 and Table 3 below.

  As can be seen from Tables 1 to 3, the ink composition having an acidity of 2.75 to 4.15 can produce a transparent conductive film having excellent mechanical strength even after 7 days or more after production. It turns out that the total light transmittance and sheet resistance of the transparent conductive film obtained are good (Examples 1 to 4). In particular, it can be seen that an ink composition having an acidity of 3.00 or more and 3.50 or less can produce a transparent conductive film having excellent mechanical strength even when 21 days or more have elapsed after production (Example 2). And Example 3). Therefore, it can be seen that these ink compositions can be stored after production, and the productivity of the transparent conductive film can be improved. In this example, the sheet resistance value decreased after 4 days of the transparent conductive film. This result is considered to be due to the aging effect of dimethyl sulfoxide as an enhancer.

  On the other hand, when acidity is less than 2.75, it turns out that the mechanical strength of the transparent conductive film obtained when 1 day passes after preparation falls remarkably (Comparative Examples 1 to 3). . This result is considered to be because the addition ring-opening reaction between PEDOT: PSS and the epoxysilane compound, and the hydrolysis and condensation reaction of the epoxysilane compound proceeded in the ink composition because the acidity of the ink composition was low. It is done. Therefore, it can be seen that when these ink compositions are used, it is necessary to use the ink composition immediately after production for production of the transparent conductive film, which affects the productivity of the transparent conductive film. Moreover, when acidity exceeds 4.15, it turns out that the mechanical strength of the transparent conductive film obtained when 1 hour passes after preparation falls (comparative example 4). This result is considered to be due to the progress of gelation in the ink composition. As described above, in the ink compositions according to Comparative Examples 1 to 4, since the mechanical strength of the transparent conductive film obtained when the ink composition is stored for 1 day or longer is reduced, the area is increased by the aging effect by the enhancer. It turns out that a resistance value falls and the transparent conductive film excellent in mechanical strength is not obtained.

  Next, the inventors prepared an ink composition in which the acidity was adjusted to a predetermined value by changing the content of the aminosilane compound in the ink composition according to the second embodiment of the present invention. After the ink composition was allowed to stand for a predetermined period, the abrasion resistance, the sheet resistance value, and the total light transmittance when a transparent conductive film was produced were examined. Hereinafter, the contents examined by the present inventors with reference to Examples 5 to 8 and Comparative Examples 5 to 8 will be described.

<Example 5>
(Preparation of ink composition)
(C1) Instead of dimethylaminoethanol, (C2) 3-aminopropyltriethoxysilane (trade name: Z-6011, manufactured by Toray Dow Corning) as an aminosilane compound is used, and the acidity of the ink composition is 2. An ink composition was prepared in the same manner as in Example 1 except that the components (B) and (C2) were mixed so as to be 55. The weight ratio of the component (B) and the component (C2) and the acidity of the ink composition are shown in Table 4 below.

(Preparation of transparent conductive film)
A transparent conductive film was prepared and evaluated in the same manner as in Example 1 except that the storage period of the prepared ink composition was 0 days (1 hour after preparation) to 4 days. 3-aminopropyltriethoxysilane was detected from each of the produced transparent conductive films. The evaluation results are shown in Table 5 and Table 6 below.

<Example 6>
A transparent conductive film was prepared and evaluated in the same manner as in Example 5 except that the components (B) and (C2) were mixed so that the acidity of the ink composition was 2.60. 3-aminopropyltriethoxysilane was detected from each of the produced transparent conductive films. The weight ratio of the component (B) and the component (C2) and the acidity of the ink composition are shown in Table 4 below, and the evaluation results are shown in Table 5 and Table 6 below.

<Example 7>
A transparent conductive film was prepared and evaluated in the same manner as in Example 5 except that the components (B) and (C2) were mixed so that the acidity of the ink composition was 2.70. 3-aminopropyltriethoxysilane was detected from each of the produced transparent conductive films. The weight ratio of the component (B) and the component (C2) and the acidity of the ink composition are shown in Table 4 below, and the evaluation results are shown in Table 5 and Table 6 below.

<Example 8>
A transparent conductive film was prepared and evaluated in the same manner as in Example 5 except that the components (B) and (C2) were mixed so that the acidity of the ink composition was 2.85. 3-aminopropyltriethoxysilane was detected from each of the produced transparent conductive films. The weight ratio of the component (B) and the component (C2) and the acidity of the ink composition are shown in Table 4 below, and the evaluation results are shown in Table 5 and Table 6 below.

<Comparative Example 5>
A transparent conductive film ink composition was prepared in the same manner as in Example 5 except that the component (C2) was not added to the ink composition. The acidity of the ink composition was 2.40. 3-Aminopropyltriethoxysilane was not detected from each of the produced transparent conductive films. The weight ratio of the component (B) and the component (C2) and the acidity of the ink composition are shown in Table 4 below, and the evaluation results are shown in Table 5 and Table 6 below.

<Comparative Example 6>
A transparent conductive film was prepared and evaluated in the same manner as in Example 5 except that the components (B) and (C2) were mixed so that the acidity of the ink composition was 2.45. 3-aminopropyltriethoxysilane was detected from each of the produced transparent conductive films. The weight ratio of the component (B) and the component (C2) and the acidity of the ink composition are shown in Table 4 below, and the evaluation results are shown in Table 5 and Table 6 below.

<Comparative Example 7>
A transparent conductive film was prepared and evaluated in the same manner as in Example 5 except that the components (B) and (C2) were mixed so that the acidity of the ink composition was 2.50. 3-aminopropyltriethoxysilane was detected from each of the produced transparent conductive films. The weight ratio of the component (B) and the component (C2) and the acidity of the ink composition are shown in Table 4 below, and the evaluation results are shown in Table 5 and Table 6 below.

<Comparative Example 8>
A transparent conductive film was prepared and evaluated in the same manner as in Example 5 except that the components (B) and (C2) were mixed so that the acidity of the ink composition was 3.10. 3-aminopropyltriethoxysilane was detected from each of the produced transparent conductive films. The weight ratio of the component (B) and the component (C2) and the acidity of the ink composition are shown in Table 4 below, and the evaluation results are shown in Table 5 and Table 6 below. In Comparative Example 8, the ink composition gelled during storage, and a transparent conductive film could not be produced.

  As can be seen from Tables 4 to 6, the ink composition having an acidity (pH) of 2.55 to 3.00 can produce a transparent conductive film excellent in mechanical strength even after 1 day or more after the production. It becomes possible, and it turns out that the total light transmittance and sheet resistance of the transparent conductive film obtained are favorable (Examples 5 to 8). In particular, it can be seen that an ink composition having an acidity of 2.60 or more and 2.70 or less can produce a transparent conductive film having excellent mechanical strength even after 4 days or more after production (Example 6). And Example 7). Therefore, it can be seen that these ink compositions can be stored after production, and the productivity of the transparent conductive film can be improved.

  Further, in this example, the area resistance value decreased after 4 days of the transparent conductive film, but this result was obtained by aging with dimethyl sulfoxide as an enhancer as in Examples 1 to 4 described above. This is probably due to the effect. In addition, the transparent conductive film using the ink composition according to Examples 5 to 8 is better in area resistance than the transparent conductive film using the ink composition according to Examples 1 to 4. . As a result, (C2) aminosilane compound forms a cross-linking bond with (B) epoxysilane compound by hydrolysis reaction and condensation reaction, and therefore a stronger three-dimensional network is formed in the transparent conductive film. it is conceivable that.

  On the other hand, when the acidity is less than 2.55, it can be seen that the mechanical strength of the transparent conductive film obtained when one day has elapsed after the production is remarkably reduced (Comparative Example 5 to Comparative Example 7). . This result is considered to be because the addition ring-opening reaction between PEDOT: PSS and the epoxysilane compound, and the hydrolysis and condensation reaction of the epoxysilane compound proceeded in the ink composition because the acidity of the ink composition was low. It is done. Therefore, it can be seen that when these ink compositions are used, it is necessary to use the ink composition immediately after production for production of the transparent conductive film, which affects the productivity of the transparent conductive film. When the acidity was 3.10, the transparent conductive film could not be formed because gelation proceeded in the ink composition immediately after the ink composition was prepared (Comparative Example 8). As described above, in the ink compositions according to Comparative Examples 5 to 8, the mechanical strength of the transparent conductive film obtained when the ink composition is stored for 1 day or more after the ink composition is prepared is reduced. It turns out that a resistance value falls and the transparent conductive film excellent in mechanical strength is not obtained.

  In addition, this invention is not limited to the said embodiment, It can change and implement variously. In the above-described embodiment, the PEDOT: PSS aqueous solution, the epoxysilane compound, and the amine compound are not limited thereto, and can be appropriately changed and used within a range in which the effects of the present invention are exhibited. In addition, the present invention can be appropriately modified and implemented without departing from the scope of the object of the present invention.

  INDUSTRIAL APPLICABILITY The present invention has an effect that a storage stability is good and an ink composition, a transparent conductive film, and an electronic component that can improve the productivity of a transparent conductive film can be realized. The present invention is applicable to devices using various transparent conductive films such as transparent electrodes and electromagnetic wave shields used for displays, electrochromic displays, solar cells, touch panels, electronic papers, and the like.

Claims (8)

(A) a polyethylenedioxythiophene / polystyrenesulfonic acid aqueous solution;
(B) an epoxy silane compound;
(C1) dimethylaminoethanol,
An ink composition having an acidity of 2.75 or more and 4.15 or less.   The weight ratio of the (B) epoxysilane compound to the (C1) dimethylaminoethanol is in the range of (B) component: (C1) component = 80: 20 to 85:15. The ink composition according to 1. (A) a polyethylenedioxythiophene / polystyrenesulfonic acid aqueous solution;
(B) an epoxy silane compound;
(C2) an aminosilane compound,
An ink composition having an acidity of 2.55 or more and 3.00 or less.   The weight ratio of the (B) epoxysilane compound and the (C2) aminosilane compound is in the range of (B) component: (C2) component = 67: 33 to 83:17. The ink composition as described.   5. The ink composition according to claim 3, wherein the (C2) aminosilane compound is 3-aminopropyltriethoxysilane.   The ink composition according to any one of claims 1 to 4, wherein the (B) epoxysilane compound is 3-glycidoxypropyltrimethoxysilane.   A transparent conductive film obtained by using the ink composition according to claim 1.   An electronic component comprising the transparent conductive film according to claim 7.

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