KR102562916B1 - Forming composition of ground electrodes comprising conductive polymer and preparation method thereof - Google Patents

Abstract

The present invention relates to a composition for forming a back electrode including a water-based conductive polymer solution having excellent hardness and surface resistance while maintaining stable physical properties, a binder, and a solvent, and a method for preparing the same.
The composition of the present invention has high surface hardness despite the use of a conductive polymer, and is superior to conventional compositions in terms of change in surface resistance over time and storage stability, so that it can replace conventional back electrodes using metal oxides and can be used in various liquid crystal panels.

Description

Composition for forming a back electrode containing a conductive polymer and method for preparing the same {Forming composition of ground electrodes comprising conductive polymer and preparation method thereof}

The present invention relates to a composition for forming a back electrode and a method for manufacturing the same, and more particularly, for forming a back electrode including a water-based conductive polymer solution, a binder, and a solvent to maintain stable physical properties while having excellent hardness and surface resistance. It relates to a composition and a method for preparing the same.

The composition of the present invention has characteristics superior to conventional compositions in terms of surface resistance change over time and storage stability.

It is necessary to form an antistatic layer on a color filter substrate, which serves to prevent static electricity from the outside of an electrode in a panel such as a liquid crystal display, and various materials are used. Specifically, ITO (Indium-Tin-Oxide) or IZO (Indium-Zinc-Oxide) is used, but these require a vacuum deposition process, and have excellent resistance and surface hardness in their characteristics, but have a disadvantage in that transmittance is not excellent.

In addition, the price of ITO or IZO is continuously rising, and the cost of these deposition processes is also very high, so it is necessary to develop new materials that can replace these materials.

Various efforts have been made to utilize conductive polymers that are more flexible and have better permeability than metal oxides while overcoming these disadvantages. can't show

First, the anxiety factor is the instability of the coating liquid composition for the shelf life. In the case of forming a dry coating film immediately after preparation of the composition, the preceding techniques have excellent adhesion to the glass substrate and stably realize surface resistance on the surface of the dry coating film. However, as the storage period of the coating liquid composition as a liquid elapses (expiration of shelf life), when the coating liquid is applied after a certain period of time to form a dry coating film, the adhesion of the dry coating film decreases and the surface resistance value increases. A problem arises Since the preceding technologies have a very short shelf life in which stable physical properties are realized, they must be used limitedly within a certain period after manufacture.

The second anxiety factor is the aging of the dry film. After the dry coating film is heat-cured, the surface resistance changes as time passes. In general, the surface resistance value of the dry coating film shows good results at the beginning, but the surface resistance tends to increase as the hardness increases or micro cracks occur over time. It is very important that the physical properties implemented in the dry film are maintained for a long period of time without any change in the dry film over time.

Therefore, as a silane composition containing a conductive polymer in a liquid crystal panel, it is required to develop a new composition that can be stably maintained while extending the shelf life and can be used in the panel manufacturing process with surface resistance or hardness.

Korean Patent Application No. 2013-0154635 Conductive composition for forming rear electrode of liquid crystal display device Korean Patent Application No. 2015-0191575 Manufacturing method of anti-static film and manufacturing method of display device

In order to solve the problems of the prior art as described above, an object of the present invention is to provide a composition for forming a back electrode with excellent physical properties of hardness and surface resistance and a manufacturing method thereof. In particular, the purpose is to maintain stable surface resistance and hardness even when a conductive polymer is used rather than a metal ion or surfactant, and to enable complete curing of a coating film during heat curing without using a separate curing agent.

In order to achieve the above object, the present invention provides a composition for forming a rear electrode including a water-based conductive polymer solution, a binder and a solvent.

In addition, the present invention comprises the steps of a) preparing a mixed solution by mixing a binder and a solvent;

b) adding a conductive polymer solution to the solution; and

c) hydrolysis of the conductive polymer and the binder;

In addition, the present invention comprises the steps of a) coating a composition for forming a rear electrode on a substrate;

b) heating and curing the coated substrate; and

c) reacting the composition to have a three-dimensional network structure formed by a condensation reaction;

The composition for forming a rear electrode of the present invention has high surface hardness despite the use of a conductive polymer, and excellent surface resistance change over time and storage stability, so it can replace conventional rear electrodes using metal oxides and can be used in various liquid crystal panels. There is an advantage to being

1 shows changes in the molecular structure of TEOS before and after hydrolysis.
2 shows an example of a dehydration condensation reaction of hydrolyzed TEOS (Si-(OH) ₄ ).
3 shows a schematic diagram of a TEOS dry (curing) coating film after a dehydration condensation reaction.
Figure 4 is a graph showing the change in solid percentage (%) according to the number of dehydration condensation reactions.
Figure 5 shows the structures of the four silanes after being hydrolyzed.
Figure 6 is a graph showing the change in solid content of the composition of Table 2 according to the long-term heat curing.
7 shows the stability test results of Example 5 and Comparative Example 5. (a) TEOS with Et-OH, (b) MTES with Et-OH, (c) MTES with IPA.

Hereinafter, the present invention will be described in detail.

The present invention relates to a composition for forming a rear electrode including a water-based conductive polymer solution, a binder, and a solvent.

In one aspect, the binder is a mixture of MTES (methyl triethoxy silane) and DMDES, and preferably, the binder is mixed with 5 to 15 parts by weight of DMDES solid content based on 100 parts by weight of MTES solid content.

The binder is preferably a silane-based compound, and may be one or more compounds selected from the group consisting of alkyloxy silanes, vinyl silanes, epoxy silanes, methacryloxy silanes, isocyanate silanes, and fluorine silanes.

Preferably, they are silazanes, silanes, and siloxanes. Examples of the compound include methyltrichloro silane (MTS), tetraethyl orthosilscate (TEOS), tetramethyl orthosilscate (TMOS), hexamethyldisiloxane (HMDSO), methyltrimethoxy silane (MTMS), methyltriethoxy silane (MTES), vinyltrimethoxy silane (VTMS), vinyltriethoxy silane (VTES), diethyl vinylsilane (diethylvinyl silane; DEVS), ethylmethoxy silane (EMS), tetramethyl silane (TMS), ethyltrimethoxy silane (ETMS), tetraethoxy silane; TES), triethyl silane (TES), dimethyldiethoxy silane (DMDES), cyclohexylmethyl-dimethoxy silane (CMDMS), dicyclophentyl-dimethoxysilane diphenyldimethoxy silane (DCDMS), phenyltriethoxy silane (PES), diphenyldimethoxy silane (DPDMS), tetramethyldisiloxane (TMDSO), hexamethyltrisiloxane (HMTSO), It may be any one compound selected from tetramethylcyclotetrasiloxane (TMCTS) and hexamethyldisilazane (HMDSN) or a mixture of two or more compounds, most preferably MTES (methyl triethoxy silane) and DMDES (dimethyldiethoxy silane). Preferably, the binder is mixed with 5 to 15 parts by weight of DMDES solid content based on 100 parts by weight of MTES solid content.

In one aspect, the solvent is isopropanol (IPA).

The solvent is methyl alcohol, ethyl alcohol, isopropanol, ethylene glycol, butanediol, neopentyl glycol, 1,3-pentanediol, 1,4-cyclohexanedimethanol, diethylene glycol, polyethylene glycol, polybutylene glycol, and dimethylol propane. , trimethylolpropane, propylene glycol monomethyl ether, normal methylpyrrolidone, dimethyl sulfoxide, and may be one or more selected from the group consisting of water, preferably isopropanol (IPA).

In one aspect, the conductive polymer is Pedot-PSSA. The conductive polymer may be at least one compound selected from the group consisting of polyaniline-based polymers, polypyrrole-based polymers, and polythiophene-based polymers, and preferably, poly(3,4-ethylene, which is a kind of polythiophene-based polymers). deoxythiophene) (Pedot). Dopants are dodecylbenzenesulfonic acid, toluenesulfonic acid, camphorsulfonic acid, benzenesulfonic acid, hydrochloric acid, styrenesulfonic acid, 2-acrylamido-2-methylpropanesulfonic acid, 2-sulfosuccinic acid ester salt, sodium 5-sulfoisophthalic acid, dimethyl It may be one or more compounds selected from the group consisting of -5-sodium sulfoisophthalate and 5-sodium sulfo-bis(β-hydroxyethylisophthalate), preferably poly(4-styrenesulfonate) is PSS. Preferably, a dopant is mixed with a polymer and used, and most preferably, PEDOT-PSS is obtained by adding PSS as an anionic dopant to PEDOT.

When MTES (tri-functional group) is used instead of TEOS (tetra-functional group), MTES is a substance with lower polarity than TEOS, and its compatibility with water is not as good as TEOS.

In the present invention, in order to impart conductivity to the surface of the dry film, the conductive polymer (Pedot-PSSA number in the range of at least 20% to 30% by weight (range of 20g to 30g with respect to 100g of the composition by weight) of 100% by weight of the total composition dispersion) can be used. Preferably, 25% by weight of the conductive polymer may be used.

In one aspect, the water-based conductive polymer solution is 20 to 30% by weight; A composition comprising 2 to 5% by weight of a binder and 65 to 75% by weight of a solvent. Preferably, the water-based conductive polymer solution is 20 to 25% by weight; 2 to 5% by weight of the binder and 70 to 73% by weight of the solvent. In one aspect, the solid content of the conductive polymer is 14 to 21 parts by weight based on 100 parts by weight of the binder solid content.

In addition, the preferred binder solids content should be in the range of 2% to 2.5% in 100 g of the total composition.

Including 25 g of the conductive polymer (1.4% solid content, 98.6% water content) in 100 g of the composition is equivalent to containing about 25 g of water in 100 g of the composition.

In addition, the present invention comprises the steps of a) preparing a mixed solution by mixing a binder and a solvent;

b) adding a conductive polymer solution to the solution; and

It relates to a method for preparing a composition for forming a back electrode, including c) hydrolyzing the conductive polymer and the binder.

In one aspect, step c) is reacted for 24 hours or more.

If it is shorter than 24 hours, sufficient hydrolysis may not occur, so it is preferable to secure sufficient time.

In addition, the present invention comprises the steps of a) coating a composition for forming a rear electrode on a substrate;

b) heating and curing the coated substrate; and

c) reacting the composition to have a three-dimensional network structure formed by a condensation reaction;

In one aspect, step b) is preferably heat-cured at 110 to 130°C for 2 to 4 hours or 140 to 160°C for 1 to 3 hours. The temperature and time ranges are optimal ranges considering high hardness and low surface resistance through experiments on physical properties of pencil hardness and surface resistance.

In one aspect, the back electrode has a pencil hardness of 7H or more and a surface resistance of 10_7 or less.

As the coating method on the substrate, a conventional coating method in the technical field to which the present invention pertains may be applied without limitation, and preferably may be a spray method, a roll coating method, a dipping method, and the like.

<Selection of Binder>

Among the inorganic materials used as conventional binders, Tetra-Ethyl Ortho-Silicate (TEOS) is a typical silane-based coupling agent and has four alkoxy groups (TEOS is an ethoxy group). Hydrolysis (addition) of water with an acid catalyst can decompose 4 alkoxy groups (ethoxy groups) into 4 alcohols (ethanol), which is collectively referred to as the hydrolysis reaction of TEOS. In the hydrolyzed TEOS, -OH is generated in place of the alkoxy group, and finally four hydroxyl groups (-OH) are given. TEOS before hydrolysis is a water-insoluble material that does not mix directly with water. However, in hydrolyzed TEOS, the alkoxy group at the end of the molecule is replaced with a hydroxyl group (-OH) to increase polarity and increase hydrophilicity, making it a substance that can be mixed stably with water. That is, the hydrophilicity is also increased to become a material that can be stably mixed with water.

Figure 1 shows the change in the molecular structure of TEOS before and after hydrolysis. At this time, the molecular weight of the TEOS molecule by the hydrolysis reaction is 208.33 g / mol (before hydrolysis) to 96.114 g / mol (hydrolysis) After decomposition), it is changed (reduced).

Although the substance produced after hydrolysis (Si-(OH) ₄ ) has a chemical structure distinctly different from that of TEOS (Si-(OCH ₂ CH ₃ ) ₄ ) before hydrolysis, “hydrolyzed TEOS (Si-(OH) ) ₄ )”. Hydrolyzed TEOS (Si-(OH) ₄ ) undergoes a dehydration condensation reaction as water and solvents evaporate under high-temperature heating and drying conditions, resulting in a cross-linking reaction, ultimately resulting in a hardened coating film of high hardness. . As shown in the example of the dehydration condensation reaction of hydrolyzed TEOS (Si-(OH) ₄ ) in FIG. 2 , the hydrolyzed TEOS (Si-(OH) ₄ ) produces one molecule of H ₂ as one dehydration condensation reaction proceeds. Release O and share one O (oxygen). Therefore, when calculated based on two molecules of hydrolyzed TEOS (Si-(OH) ₄ ), one dehydration condensation reaction causes a loss of mass by the molecular weight corresponding to one molecule of dehydrated water (H ₂ O).

The molecular weight loss due to dehydration condensation can be defined as nx (1/2) x (molecular weight of H ₂ O), where n is the number of dehydration condensations.

When all 4 -OH groups present in TEOS undergo dehydration condensation, ₄ water molecules are generated, which is calculated based on one Si group. : 96.114 g/mol), a loss occurs as much as 1/2 of the dehydrated water molecule.

In this case, the weight loss can be defined as the number of reactors x 0.5 x molecular weight of water, and since 4 reactors have undergone dehydration, it can be calculated as 4x0.5x18.015 g/mol = 36.03g/mol.

The case where all reactive groups (-OH) of hydrolyzed TEOS (Si-(OH) ₄ ) are completely dehydrated condensation can be defined as “complete curing” of the dry coating film, and the actual weight measured at this time is the dehydration-condensed TEOS (Si -O ₂ ) becomes the molecular weight.

3 shows a schematic diagram of a TEOS dried (cured) coating film after a dehydration condensation reaction. In this case, the molecular weight per molecule of fully cured TEOS (dehydration condensed TEOS (Si-O ₂ )) will be 60.084 g/mol.

The molecular weight of TEOS (Si-(OCH ₂ CH ₃ ) ₄ before hydrolysis is 208.33 g/mol, and the molecular weight of TEOS (Si-(OH) ₄ after hydrolysis is 96.114 g/mol, compared to TEOS before hydrolysis) After complete curing, the molecular weight of TEOS (Si-O ₂ ) is 60.084 g/mol (=96.114 g/mol -36.03 g/mol), which is about 72% lower than that of TEOS before hydrolysis. .

Under ideal conditions, when TEOS is fully cured through hydrolysis and dehydration condensation, the yield of fully cured TEOS (Si-O ₂ ) after hydrolysis is higher than that of TEOS (Si-(OCH ₂ CH ₃ ) ₄ before hydrolysis. The solid content can be calculated as about 28.84% (solid content = molecular weight after dehydration/molecular weight before hydrolysis x 100 = 60.084 g / 208.33 g x 100).

This means that if 100 g of TEOS (Si-(OCH ₂ CH ₃ ) ₄ before hydrolysis, which acts as a binder in the water-soluble coating composition, is added, 28 g of solid content can be obtained in the dry coating film.

Based on the general common sense described above, in the dehydration condensation reaction of TEOS, the change in solid content loss according to the progress of the dehydration condensation reaction can be summarized in more detail.

The tetrafunctional TEOS can undergo 4 dehydration condensation reactions, and the change in average molecular weight was calculated by dividing them into stages. The result is shown in the table below.

number State of TEOS constitutional formula Molecular Weight active ingredient,
Solid content (%) One before hydrolysis (OCH ₂ CH ₃ ) ₄ -Si 208.33 g/mol 100% 2 after hydrolysis (OH) ₄ -Si 96.114 g/mol 46.14% 3 1 dehydration condensation (OH) ₃ -Si-O _(1x0.5) 87.106 g/mol 41.81% 4 2 dehydration condensation (OH) ₂ -Si-O _(2x0.5) 78.096 g/mol 37.49% 5 3 dehydration condensation (OH) ₁ -Si-O _(3x0.5) 69.091 g/mol 33.16% 6 Dehydration condensation 4 Si-O _(4x0.5) 60.084g/mol 28.84%

Table 1 shows the calculated values of changes in molecular weight (g/mol) and solid content (%) according to hydrolysis and dehydration condensation of TEOS. Figure 4 is a graph showing the change in solid percentage (%) according to the number of dehydration condensation reactions. The solid content (%) value of the second stage of dehydration condensation of TEOS is 37.49%, and the solid content (%) value of the third stage is 33.16%. Calculating and predicting the change in solid content according to each reaction step can be an important basis for confirming the two indicators of the coating liquid.

The first is the cured state of the dry film. By measuring the solid content after preparing the coating solution, it becomes a basis for understanding the degree of dehydration and condensation of the dried coating film.

Second, it is possible to grasp the curing conditions to reach the theoretical final solid content, that is, the optimal heating temperature and heat curing time required to realize complete curing of the coating film.

<Optimization of curing conditions>

In order to optimize the curing conditions, an experiment was conducted with the composition shown in Table 2 below to confirm the relationship between the drying temperature and time and the degree of crosslinking through the change in solid content according to the drying temperature and time based on TEOS.

% note Ethanol 81.313 TEOS (NV=28.84%) 13.870 (NV=28.84%) Di Water 4.797 35% HCL aqueous solution 0.020 Total 100.00 NV (%) theoretical value 4

With the composition of Table 2, the solid content value for each temperature according to dehydration condensation heat curing was measured, and the results are shown in FIG. 6. According to the above results, the theoretical solid content value of 28.84% that can be reached when 100% dehydration of TEOS was reached was not reached in all temperature ranges. However, the dry coating film (300 nm) of the TEOS composition satisfies the hardness of 9H even under curing conditions of 120°C for 1 hour. However, it can be seen that under this condition, there is a possibility that a large amount of TEOS (uncured) without dehydration condensation may remain.

Only TEOS having 4 reactive functional groups will realize high hardness. Generally, when a composition is prepared using silanes having tri-functional groups and less functional groups, and then thermally cured and dried, the pencil hardness of the dry film is about 3H. is judged to appear. Almost all silanes and silane derivatives, except for TEOS, are trifunctional or less functional groups that can induce dehydration condensation reactions, so it is judged that the experiments are not conducted in practice. The conclusions obtained with respect to the drying characteristics of the composition using TEOS as a binder through the preceding experiments of the present invention are as follows.

1) When the curing temperature of the composition is 200° C., the degree of crosslinking of the dried coating film can achieve three levels within 2 hours of drying time.

2) When the heat curing temperature of the composition is 200°C or less (eg, 120°C, 150°C), the degree of crosslinking in the dry film of the composition is achieved between the second and third stages.

3) When the heating temperature is low and the heating time is short, when the degree of crosslinking of the composition is close to the second stage, cracks do not occur in the dry coating film.

4) When the heating time is extended or the heating temperature is increased, the degree of crosslinking of the dry film moves toward the third step.

5) Cracks occurred when the degree of crosslinking of the dry coating film was very close to step 3 or exceeded step 3.

6) At an unspecified point in time when the degree of crosslinking goes beyond step 2 and progresses to step 3, the hardness of the dry film is 9H, and the hardness of the dry film does not become 9H only when the degree of crosslinking is 4.

From a conventional point of view, a general organic polymer (polymer) that is cured by forming a three-dimensional network structure has a very long distance between functional groups where a crosslinking reaction is generated. In addition, as the distance between the crosslinking reactors increases, the flexibility of the dry coating film increases and the hardness decreases. In general, when the hardness of a dry coating film due to a crosslinking reaction of organic materials is about 3H, it is also the reason for classifying it as a high hardness dry coating film.

In the previous experiment, it was confirmed that the reason why the dry film hardness of the inorganic composition using TEOS is high may be a preconceived notion that the tetrafunctional TEOS composition achieves a hardness of 9H by implementing 4 stages of crosslinking in the dry film, In TEOS, the distance between the dehydration-condensation functional groups is very close, rather than determining that high hardness is realized due to the large number of reactive groups crosslinked by dehydration condensation, so the distance between the “crosslinking points” crosslinked by dehydration condensation in the dry film is very close and tight. Because of this, high hardness is realized, and the actual crosslinking degree shows that a hardness of 9H can be sufficiently realized if the degree of crosslinking is in the range of 2 to 3 steps instead of 4 steps.

Due to the characteristics of the dry film of TEOS, which is very hard and has severe shrinkage, when the degree of crosslinking exceeds the third level, the hardness of the dry film continues to increase, but cracks occur, which is very unfavorable for the ability to maintain a stable film.

Although it is possible to set heat-curing conditions that realize a crack-free 9H hardness for the dry coating film of tetrafunctional TEOS, it is necessary to artificially prevent the change in crosslinking degree that occurs during the shelf life or shelf life of the dry coating film after heat-curing is completed. difficult.

As an idea to solve the problem occurring in such a dry film, the present invention tried to solve it by using a trifunctional silane instead of a tetrafunctional TEOS.

Among trifunctional silanes, triethoxymethylsilane (Methyl Tri-Ethoxy Silane, Tri EthoxyMethylSilane, hereinafter referred to as “MTES”) having a relatively similar molecular weight was selected.

Di-methyl Di-Ethoxy Silane (hereinafter referred to as “DMDES”) having a similar molecular weight was selected as a bifunctional silane for crosslinking control.

Table 3 below shows the structural formula and molecular weight of trifunctional silane and bifunctional silane.

abbreviation MTES DMDES name Methyltriethoxysilane
(MethylTriethoxySilane)
triethoxymethylsilane
(TriethoxyMethylSilane) Dimethyldiethoxysilane
(Dimethyldiethoxysilane)
Diethoxydimethylsilane constitutional formula chemical formula CH ₃ Si(OC ₂ H ₅ ) ₃ (CH ₃ ) ₂ Si(OC ₂ H ₅ ) ₂ Molecular Weight 178.30 g/mol 148.28g/mol

Table 4 below is a calculation table of changes in molecular weight (solids content (%)) according to dehydration condensation of hydrolyzed silanes.

division TEOS
[Si(OC ₂ H ₅ ) ₄ ] MTES
[CH ₃ Si(OC ₂ H ₅ ) ₃ ] DMDES
[ (CH ₃ ) ₂ Si(OC ₂ H ₅ ) ₂ ] MW
(g/mol) % MW
(g/mol) % MW
(g/mol) % before hydrolysis 208.33 100% 178.3035 100% 148.2775 100% after hydrolysis 96.114 46.14% 94.1415 52.80 92.1695 62.16 1 dehydration condensation 87.106 41.81% 85.134 47.75 83.162 56.09 2 dehydration condensation 78.096 37.49% 76.1265 42.69 74.1545 50.01 3 dehydration condensation 69.091 33.16% 67.119 37.64 - - Dehydration condensation 4 60.084 28.84% - - - -

When the hydrolysis is performed by mixing the trifunctional silane and the bifunctional silane, the degree of crosslinking was calculated in the following manner in order to theoretically calculate the final degree of crosslinking of the mixed composition.

The degree of dehydration condensation crosslinking was calculated assuming that the bifunctional group was considered as a maximum of 2 steps and the trifunctional group as a maximum of 3 steps.

The calculation method is based on the assumption that the theoretical solid content of the pure inorganic binder is 100 parts by weight, excluding materials for other purposes such as conductive polymers from the total solid content of the composition when calculating the degree of crosslinking, and then the solid content of MTES (%) among the estimated total solid content of the binder. ) x 3 + solid content (%) of DMDES x 2 to calculate the final degree of crosslinking of the binder mixture.

[Equation 1]

How to Calculate Composition Crosslinking Degree

According to the above calculation method, the bridging value of the experimental example was applied.

<Improve storage stability>

Apart from the improvement in the change of the dry coating film over time, the hydrolyzed TEOS-based conductive polymer composition has a very short storage period of liquid while maintaining stable physical properties. Compared to the average storage stability of a mixture of a water-based polymer and a conductive polymer of 6 months or more, the short storage period of the inorganic binder and the conductive polymer composition cannot be determined as a phenomenon caused by the instability of the conductive polymer.

It is reasonable to assume that the cause of the extremely short storage period of the inorganic binder and the conductive polymer composition is the effect of dehydration condensation of the hydrolyzed inorganic binder at room temperature in the liquid.

When the hydrolyzed TEOS prepared in this study and the conductive polymer composition were stored at room temperature (25 ℃), refrigerated storage (4 ℃), and warm storage (60 ℃), respectively, the storage stability of the liquid showed a very large difference. This is understood to be a phenomenon that occurs as the dehydration condensation rate in the composition liquid increases as the temperature increases, and the reactivity decreases as the temperature decreases, resulting in a slow dehydration condensation reaction rate.

In order to improve the storage stability of the composition prepared in this study, it was confirmed in previous studies that it was necessary to extremely lower the content of the catalyst, and this is already one component of improving the storage stability of the composition. In addition to this, if the storage temperature of the composition is lowered in the distribution of the composition using the refrigeration storage method, it can be sufficiently predicted that the storage period of the composition can be extended.

After hydrolysis, the four silanes have a similar type of structure. A simple diagram of this is shown in FIG. 5 .

Referring to FIG. 5, that is, the space occupied form of hydroxy (-OH) may change depending on the size of the alkyl group, which will affect the "reaction rate" in the dehydration condensation reaction.

In the hydrolyzate of triethoxysilane (TES) where the hydrogen atom (H) is located, which is a case where the size is very small at the position of the R group, the three hydroxyl groups (-OH) in the molecular structure are widely distributed at almost flat positions something to do. And the dehydration condensation reaction between different molecules can be expected to proceed very quickly compared to other trifunctional silanes compared in this study.

Conversely, in the case of a very large size of R, the hydrolyzate of 3-glycidoxypropyltriethoxysilane (3-GPTES) has three hydroxyl groups (-OH) narrowed to a very narrow space in the molecular structure and can be distributed. will be. And the dehydration condensation reaction between the hydrolyzate molecules can be expected to be very slow.

Finally, as the size of the R group increases, the rate of dehydration condensation reaction will be more affected by the second-step dehydration-condensation reaction than the first-step dehydration-condensation reaction, and will have a greater effect on the third-step dehydration-condensation reaction.

This means that when heating hardening a hydrolyzate having a large R group, the drying of the coating film becomes very slow or a higher heating temperature than average may be required, but conversely, the dehydration condensation reaction occurring in the liquid at room temperature is very slow. As it will appear, it will be a more effective way to improve the room temperature stability of liquids.

In addition, this will be a sufficient reason for the fact that the hydrolyzed composition of trifunctional or bifunctional silanes has better storage stability at room temperature than the hydrolyzate of tetrafunctional TEOS.

<Selection of solvent>

TEOS before hydrolysis is incompatible with water, but TEOS after hydrolysis is substituted with 4 hydroxyl groups (-OH) to increase hydrophilicity, and for this reason, has good compatibility with water. In contrast, in trifunctional MTES, after hydrolysis, three hydroxyl groups (-OH) are substituted and one methyl group (-CH ₃ ) remains. Therefore, after hydrolysis, the water compatibility is poor compared to TEOS. As a way to solve this problem, reducing the water content and increasing the solvent content is a direction that can be considered, but since the water content supplied to the present composition means the water content contained in the conductive polymer, artificially adjusting the water content It is very difficult.

In order to improve the aqueous solution stability of hydrolyzed MTES, the composition prepared in the present invention uses IPA, which has better solubility than ethanol, to improve phase stability.

<Selection of conductive polymer>

General Pedot-PSSA aqueous dispersion sold commercially as a polythiophene-based polymer dispersion has the following characteristics.

O solid content (NV %): around 1.5%

O average particle diameter (Size, nm): less than 100 nm

O pH (25°C): less than 2 acidic solution.

O Solvent: More than 98% water content.

The dopant of Pedot-PSSA aqueous dispersion is unneutralized Poly-Styrene Sulfonic Acid (PSSA) or neutralized Poly-Styrene Sulfonic Acid (PSS) with an alkaline substance such as Na.

In the present invention, among various Pedot-PSSA-based conductive polymer aqueous products on the market, an aqueous conductive polymer dispersion prepared by using non-neutralized acidic polystyrenesulfonic acid (PSSA) as a dopant is intended to be used.

Since aqueous conductive polymers of this type are generally strongly acidic materials with a pH of 2 or less, they can smoothly serve as acidic catalysts required in the hydrolysis process requiring a catalyst in preparing the composition.

Conventional prior art generally uses a catalyst for preparing the composition, and serves to accelerate the hydrolysis reaction of the binder material. All kinds of acidic substances can be used as catalysts. It is common to use aqueous hydrochloric acid as a standard acidic catalyst. However, in recent years, inorganic acids such as sulfuric acid and phosphoric acid or organic acids such as formic acid and acetic acid have been used to avoid environmental regulations on halogen compounds. However, various problems arise with the use of catalysts. 1) As the content of the catalyst increases, the storage stability of the liquid phase quickly deteriorates, 2) As the content of the catalyst increases, seeding and precipitation occur quickly, and 3) As the content increased, the surface resistance quickly deteriorated.

On the other hand, the Pedot-PSSA aqueous dispersion, an acidic material of the present invention, was used as a catalyst and showed the best storage stability despite not using a separate catalyst. This is because when the composition is prepared using the acidic Pedot-PSSA aqueous dispersion as a catalyst, there is a problem in that the production process is prolonged due to low heat generation and low reactivity during the hydrolysis reaction of the composition, but it is difficult to implement stable storage stability of the composition. It was confirmed that a catalyst is unnecessary for this.

[Example 1 and Comparative Example 1]

In order to confirm the storage stability according to the type of binder of the present invention, Examples and Comparative Examples were prepared with the compositions shown in Table 5 below. The input amount of TEOS was calculated as 33.16% of the expected solid content (%) based on the degree of crosslinking 3. The higher the inorganic binder content of the composition, the faster the storage property deteriorates. In order to compare the storability of the composition and the propensity for cracking of dry coating films, the solid content (%) of the composition was prepared at 5%. In order to accurately observe the liquid phase stability, water was used instead of the colored conductive polymer as much as the expected amount of conductive polymer. The water content required for hydrolysis was indicated as Di-water (1), and water was additionally added to control the water content deviation between the comparison test groups to the same content, and this was indicated as Di-Water (2). As a catalyst, 0.02% of 35% aqueous hydrochloric acid was used. Hydrolysis was carried out at room temperature for 25 hours.

division Comparative Example 1-1 Comparative Example 1-2 Example 1 Comparative Example 1-3 note (hydrolysis) (3.0) (3.0) (3.0) M.W (g/mol) One IPA 790.10 794.02 811.96 861.56 2 TES (NV: 32.32%) 154.70 164.28 g/mol 3 TEOS (NV: 33.16%) 150.78 208.44g/mol 4 MTES (37.64%) 132.84 178.30g/mol 5 3GPTES (NV: 60.07%) 83.24 278.42 g/mol 6 Di-Water (1) 50.89 52.13 40.26 16.16 for hydrolysis 7 35% HCL aqueous solution 0.20 0.20 0.20 0.20 8 Di-Water (2) 4.11 2.87 14.74 38.84 for content control Total 1000.00 1000.00 1000.00 1000.00 Composition solids (theoretical value, %) 5.0 5.0 5.0 5.0

[Experimental Example 1]

<1-1> Comparison of composition liquid storage stability according to silane functional groups. (Based on 5% solid content)

The composition of Table 5 was stored at room temperature in order to see the liquid storage properties of Example 1 and Comparative Example 1. The results are shown in Table 6 below.

division Comparative Example 1-1 Comparative Example 1-2 Example 1 Comparative Example 1-3 (Inorganic type) TES TEOS MTES 3GPTES One after manufacturing Haze occurs Good Good Good 2 3 days (72 hours) gel generation Good Good Good 3 1 week later X settling, seeding Good Good 4 2 weeks later X gel generation Good Good 5 3 weeks later X X Good Good 6 After 4 weeks (1 month) X X fine seeding Good 7 6 weeks later X X floor separation Good 8 After 8 weeks (2 months) X X X Good 9 After 25 weeks (6 months) X X X Good

As shown in Table 6, the triethoxy silane (TES) hydrolyzate of Comparative Example 1-1 gelled at a very rapid rate compared to the tetraethoxysilane (TEOS) hydrolyzate of Comparative Example 1-2. .

The hydrolyzate of methyltriethoxysilane (MTES) in Example 1 showed markedly improved storage stability at room temperature compared to the hydrolyzate of tetraethoxysilane (TEOS).

3-glycidoxypropyl triethoxysilane (3GPTES) of Comparative Examples 1-3 showed very good solution storage stability compared to methyltriethoxysilane (MTES) and tetraethoxysilane (TEOS), and 6 months Stability was maintained even after the storage period above.

<1-2> Dry film thickness and crack test method of Example 1 and Comparative Example 1

The composition was coated on tempered glass having a thickness of 5 mm and a size of 150 mm x 150 mm with a wet film thickness of 12.5 μm using Baker Applicator YBA-3. Curing was performed by heating immediately according to each drying temperature after coating without performing a preheating process. Curing was carried out at room temperature (25 ° C) under heat curing conditions, and then the temperature was raised by 20 ° C from 60 ° C to 200 ° C, and curing was performed for 1 hour each. When the specific gravity value of the liquid is not corrected, the thickness of the theoretical final dry film is defined as wet film thickness x solid content (%). It was assumed to be the coating thickness. When cracks did not occur after drying, the dry state was predicted by measuring pencil hardness, and when cracks occurred, pencil hardness was not measured.

These are the pencil hardness and crack test results for each temperature of Example 1 and Comparative Example 1, and the dry film thickness is about 600 to 650 nm.

division 7-1 7-2 7-3 7-4 (inorganic
type) TES TEOS MTES 3GPTES One Normal temperature (25℃) X/ Cracks after drying Crack after 7 days 2 months later fine crack undried 2 60℃ x 1hr X/crack 2B/ 3 day hook rack 3B/Good undried 3 80℃ x 1hr X/crack Crack after 4H/1 day 3H/Good undried 4 100℃ x 1hr X/crack 6H/crack 4H/Good undried 5 120℃ x 1hr X/crack X/crack 5H/Good 2H/Good 6 150℃ x 1hr X/crack X/crack 7H/Good 6H/Good 7 180℃ x 1hr X/crack X/crack X/crack 7H/fine crack 8 200℃ x 1hr X/crack X/crack X/crack X/crack

Note: X = not measurable

<1-3> Pencil hardness and crack test

These are the pencil hardness and crack test results of Example 1 and Comparative Example 1 at 120° C. heat curing, and the dry film thickness is about 600 to 650 nm.

division 7-1 7-2 7-3 7-4 (inorganic
type) TES TEOS MTES 3GPTES One 120℃ x 1hr X/crack X/crack 5H/Good 2H/Good 2 120℃ x 2hr X/crack X/crack 7H/Good 3H/Good 3 120℃ x 3hr X/crack X/crack 8H/Good 4-5H/Good 4 120℃ x 4hr X/crack X/crack X/fine crack 6H/Good 5 120℃ x 24hr X/crack X/crack X/crack 8H/fine crack 6 120℃ x 48hr X/crack X/crack X/crack 8H/fine crack

Note: X = not measurable

As shown in the results of Tables 7 and 8, the triethoxy silane (TES) hydrolyzate was unstable due to haze in the liquid phase and high viscosity after 24 hours of hydrolysis. In addition, it showed a very fast drying speed when drying after coating, but the film formation was poor, so it could not be meaningful as a comparison group.

Tetraethoxysilane (TEOS) hydrolyzate showed a drying speed fast enough to measure pencil hardness even under the drying condition of 60 ° C. x 1 hour, but cracks occurred when the dried film was left at room temperature for a certain period of time.

Tetraethoxysilane (TEOS) hydrolyzate does not crack when the dry film thickness is less than about 300 nm and under the drying conditions of 120 ° C x 1 hour. However, as in this experiment, when the dry film thickness is about 600 nm, it Cracks occurred immediately under the drying conditions of the time.

The hydrolyzate of methyltriethoxysilane (MTES) did not generate cracks up to a temperature of 150° C. based on heating for 1 hour at a dry film thickness of about 600 nm. However, considering that the hardness of the dry coating film is low, it can be seen that the dehydration condensation reaction is remarkably slow compared to the hydrolyzate of tetraethoxysilane (TEOS).

3-Glycidoxypropyl triethoxysilane (3GPTES) was undried at a temperature of 120° C. or lower and cured by heating for 1 hour. 7H pencil hardness was measured at 150 ° C x 2 hours or 180 ° C x 1 hour heat curing conditions, and 8H hardness was measured at 120 ° C x 24 hours heat curing condition.

Therefore, from the above results, as a binder, trifunctional MTES is mainly used rather than tetrafunctional TEOS, and a small amount of bifunctional DMDES is mixed to control the crosslinking degree of the dry film to lower the crosslinking degree of the entire dry film, resulting in a dry film with high hardness. It can be confirmed that it is most desirable to prevent cracks as much as possible while implementing.

[Example 2 and Comparative Example 2]

In order to compare the stability of the aqueous solution of TES hydrolyzate according to the type of solvent in the composition, Et-OH and IPA compositions in Table 9 were prepared respectively. In order to confirm the transparency, a hydrolyzate was prepared using water and a hydrochloric acid catalyst instead of the 25% Pedot-PSSA aqueous dispersion.

solution stability Comparative Example 2-1 Comparative Example 2-2 Example 2 TEOS (Et-OH) MTES (Et-OH) MTES (IPA) One EtOH 611.10 643.53 - 2 IPA - - 643.53 3 TEOS (NV; 28.84%) 138.70 - - 4 MTES (NV: 37.64%) - 106.27 106.27 5 DW* 250.00 250.00 250.00 6 35% HCL aqueous solution* 0.20 0.20 0.20 Total 1000.00 1000.00 1000.00 NV (%) theoretical value 4.0 4.0 4.0 Silane Binder NV(%) 4.00 4.00 4.00

[Experimental Example 2]

The stability comparison results are shown in FIG. 7 . (a) TEOS with Et-OH, (b) MTES with Et-OH, and (c) MTES with IPA, respectively.

The compatibility and stability of the MTES hydrolyzate containing about 25% of water is more stable when isopropyl alcohol (IPA) is mixed than when ethanol (Et-OH) is mixed. In addition, there is no side effect that can be caused by other high boiling point solvents, and there is no side effect in improving the drying speed of inorganic binders.

[Example 3 and Comparative Example 3]

In order to evaluate the effect of the catalyst on the preparation of the composition, surface resistance and storage resistance were tested with the composition shown in Table 10 below, and the results are shown in Table 10.

number division Comparative Example 3-1 Comparative Example 3-2 Example 3 One Ethanol 656.16 656.46 656.66 2 TEOS (NV=28.84%) 69.35 69.35 69.35 3 Di Water 23.99 23.99 23.99 4 35% HCL aqueous solution 0.500 0.20 0.00 5 Huclawn N3 250.00 250.00 250.00 Total 1000.00 1000.00 1000.00 TEOS NV (%) theoretical value 2.00 2.00 2.00 Conductive Polymer NV (%) 0.35 0.35 0.35 NV (%) Sum 2.35 2.35 2.35

[Experimental Example 3]

<3-1> Surface resistance and liquid stability test

The surface resistance and liquid phase stability test results of Example 3 and Comparative Example 3 are shown.

item Comparative Example 3-1 Comparative Example 3-2 Example 3 One surface resistance after manufacturing 4.9 4.8 4.9 1 week later 6.5 4.9 4.9 2 weeks later 11.2 5.2 5.1 3 weeks later OVER 12.3 6.2 4 weeks later OVER can't measure 2 liquid safety after manufacturing seeding occurs Good Good 1 week later floor separation Good Good 2 weeks later seeding occurs Good 3 weeks later floor separation Good 4 weeks later floor separation

As described above, in the coating experiment conducted at intervals of one week after storage of the composition as the content of the catalyst in Comparative Example increased, the surface resistance of the dry coating film rapidly deteriorated.

On the other hand, the aqueous dispersion of Pedot-PSSA, an acidic material of the present invention, of Example 3 was used as a catalyst, and showed the best storage stability despite not using a separate catalyst. This is because when the composition is prepared using the acidic Pedot-PSSA aqueous dispersion as a catalyst, there is a problem in that the production process is prolonged due to low heat generation and low reactivity during the hydrolysis reaction of the composition, but it is difficult to implement stable storage stability of the composition. It was concluded that it is most preferable not to use a catalyst for this purpose.

[Example 4 and Comparative Example 4]

In order to examine the hardness and surface resistance according to the content of the conductive polymer, a composition was prepared with the composition of Example 4 as shown in Table 12 below.

Example
4-1 Example
4-2 Example
4-3 Example
4-4 Example
4-5 Example
4-6 Example
4-7 conductive polymer
content 5% 10% 15% 20% 25% 30% 35% IPA 598.18 598.18 598.18 598.18 598.18 598.18 598.18 DMDES
(NV: 50.01%) 4.00 4.00 4.00 4.00 4.00 4.00 4.00 MTES
(NV: 37.64%) 47.82 47.82 47.82 47.82 47.82 47.82 47.82 Huclawn N3
(NV: 1.4%) 50.00 100.00 150.00 200.00 250.00 300.00 350.00 Di Water
(for water correction) 300.0 250.00 200.00 150.00 100.00 50.00 Total 1000.0 1000.0 1000.0 1000.0 1000.0 1000.0 1000.0 Binder solid content (theoretical value, %) 2.0 2.0 2.0 2.0 2.0 2.0 2.0 Conductive polymer (NV(%)) 0.07 0.14 0.21 0.28 0.35 0.42 0.49 NV (%) Sum 2.07 2.14 2.21 2.28 2.35 2.42 2.42 Part by weight of solid content of conductive polymer based on solid content of inorganic binder 100g 3.5 7.0 10.5 14.0 17.5 21.0 24.5

[Experimental Example 4]

<4-1> Pencil hardness measurement

This is the pencil hardness measurement result according to the heating conditions of Example 4, and is based on a dry film thickness of 250 to 300 nm.

Pencil hardness was evaluated by drawing on the surface of the dry film while applying a load of about 750 g according to the ISO 15184 standard, and confirmed by gradually increasing until a clear defect appeared on the surface of the film.

division Example
4-1 Example
4-2 Example
4-3 Example
4-4 Example
4-5 Example
4-6 Example
4-7 conductive polymer
content 5% 10% 15% 20% 25% 30% 35% 120℃ x 1hr 6H 5~6H 5~6H 5H 5H 4~5H 4H 120℃ x 2hr 7H 7H 6~7H 6~7H 6H 6H 4~5H 120℃ x 3 hours 8H 7~8H 7H 6~7H 7H 6~7H micro crack 120℃ x 4hr micro crack 8H 7~8H 7~8H 7~8H micro crack micro crack

<4-2> Pencil hardness measurement

This is the pencil hardness measurement result according to the heating conditions of Example 4, and is based on a dry film thickness of 250 to 300 nm.

division Example
4-1 Example
4-2 Example
4-3 Example
4-4 Example
4-5 Example
4-6 Example
4-7 conductive polymer
content 5% 10% 15% 20% 25% 30% 35% 150℃ x 1hr 7-8 7 7 6-7 6-7 6 5-6 150℃ x 2hr micro crack 8-9 7-8 7-8 7 7 micro crack 150℃ x 3hr micro crack micro crack micro crack micro crack micro crack micro crack micro crack 150℃ x 4hr micro crack micro crack micro crack micro crack micro crack micro crack micro crack

<4-3> Measurement of surface resistance

This is the surface resistance measurement result according to the heating conditions of Example 4, and is based on a dry film thickness of 250 to 300 nm.

Surface resistance was measured using SIMCO ST-4 (Voltage: 100V, Simco, Japan).

Surface resistance is a logarithmic function and is usually expressed in the form of a number*EX. In the present invention, it is expressed in the form of EX. It should be determined that the higher the measured value is, the higher the surface resistance value is, and the lower the measured value is, the lower the surface resistance value is.

division Example
4-1 Example
4-2 Example
4-3 Example
4-4 Example
4-5 Example
4-6 Example
4-7 Inorganic solid content (%)
(theoretical value) 2 2 2 2 2 2 2 Pedot-PSSA
Aqueous dispersion (%) content 5% 10% 15% 20% 25% 30% 35% Surface Resistance (Ω/□)
(After 120℃ x 1 hr) E8.9 E6.2 E5.8 E5.5 E5.0 E4.6 E4.3 (After 120℃ x 2 hr) E 10.3 E8.1 E6.2 E5.9 E5.2 E4.8 E4.5 (After 120℃ x 3 hr) E11.2 E9.8 E6.7 E6.2 E5.3 E5.1 - (After 120℃ x 4 hr) - E11.0 E7.1 E6.6 E5.5 - -

<4-4> Measurement of surface resistance

This is the surface resistance measurement result according to the heating conditions of Example 4, and is based on a dry film thickness of 250 to 300 nm.

division Example
4-1 Example
4-2 Example
4-3 Example
4-4 Example
4-5 Example
4-6 Example
4-7 Inorganic solid content (%)
(theoretical value) 2 2 2 2 2 2 2 Pedot-PSSA
Aqueous dispersion (%) content 5% 10% 15% 20% 25% 30% 35% Surface Resistance (Ω/□)
(After 150℃ x 1 hr) E9.5 E8.1 E6.8 E5.9 E5.3 E4.9 E4.5 (After 150℃ x 2 hr) E 12.8 E 10.2 E7.2 E6.1 E5.3 E5.1 - (After 150℃ x 3 hr) - - - E5.8 E5.4 - - (After 150℃ x 4 hr) - - - E5.5 - -

Summarizing the above results, the physical properties were the best in the 20 to 30% content of Examples 4-4 to 4-6, and the most excellent properties were shown in the composition with the 25% content of Examples 4-5. In the heat curing condition, it was generally excellent in the condition of heat curing at 110 to 130 ° C for 2 to 4 hours or at 140 to 160 ° C for 1 to 3 hours, and among them, curing at 150 ° C for 2 hours showed the best properties. .

[Example 5 and Comparative Example 5]

For comparison of compositions according to the mixing ratio of MTES and DMDES, the compositions in Table 17 below were prepared by varying the solid content of DMDEs based on parts by weight of 100 g of MTES solid content. The IPA content was adjusted so that the total amount was 1000 g.

A direct hydrolysis method using a conductive polymer was used. As shown in Table 17 below, the prescribed amount of isopropanol (IPA) and MTES and DMDES before hydrolysis were added to a 2-liter reaction vessel weighed according to the composition of each composition and stirred at a linear speed of 0.4 m/s to obtain a mixed solution ( A) prepare Prepare 250g of the aqueous conductive polymer solution and slowly add it to the mixture of isopropanol under stirring and TEOS before hydrolysis (A). After sealing the reaction vessel well and adjusting the linear speed to 0.8 m/s, hydrolysis was performed by stirring at room temperature for 24 hours. After 24 hours, the total weight of the reaction container containing the composition is measured, and isopropanol is added to each composition according to the lost weight, and mixed by stirring again.

Filter with #300 fine mesh and pack in a plastic container.

Mixture of MTES and DMDES Example 5-1 Example 5-2 Example 5-3 Example 5-4 Example 5-5 Example 5-6 Example 5-7 DMDEs by weight of MTES solids 100 g
solid content - 42g 25g 15g 11g 5g - (expected degree of crosslinking) (2.0) (2.7) (2.8) (2.85) (2.9) (2.95) (3.0) IPA 710.00 700.81 699.49 698.80 698.20 697.50 696.87 DMDES (NV: 50.01%) 39.99 12.00 8.00 6.0 4.00 2.0 0.00 MTES (NV: 37.64%) 0.00 37.19 42.51 45.2 47.82 50.5 53.13 Huclawn N3 (NV: 1.4%) 250.00 250.00 250.00 250.00 250.00 250.00 250.00 Total 1000.00 1000.00 1000.00 1000.00 1000.00 1000.00 1000.00 Composition solid content (NV (%)) 2.35 2.35 2.35 2.35 2.35 2.35 2.35 binder solids
(Theoretical value, %) 2.0 2.0 2.0 2.0 2.0 2.0 2.0 DMDES Solids
(Theoretical value, %) 2.00 0.60 0.40 0.3 0.20 0.1 0 MTES solids
(Theoretical value, %) 0.00 1.40 1.60 1.70 1.80 1.90 2.00

And in order to compare the composition of the mixed binder of MTES and DMDES, the composition of Comparative Example 5 as shown in Table 18 was prepared.

number division Comparative Example 5 reference formulation For NV 33.16% For NV 28.84% One IPA 668.62 656.46 2 TEOS (NV=33.16%) 60.31 TEOS (NV=28.84%) 69.35 3 Di Water 20.86 23.99 4 35% HCL aqueous solution 0.200 0.20 5 Huclawn N3 250.00 250.00 Total 1000.00 1000.00 TEOS NV (%) theoretical value 2.00 2.00 Conductive Polymer NV (%) 0.35 0.35 NV (%) Sum 2.35 2.35

[Experimental Example 5]

The composition of Example 5 and Comparative Example 5 was coated to a thickness of 12.5 μm using Baker Applicator YBA-3 on tempered glass having a thickness of 5 mm and a size of 150 mm x 150 mm. The solvent is evaporated by preliminary heating at 80°C for 15 minutes. Curing is induced by heating at 120°C for 1 hour. After measuring the surface resistance and hardness, heating and hardening at 120°C for 1 hour was repeated three more times. When the specific gravity value of the liquid is not corrected, the theoretical final dry film thickness is defined as wet film thickness x solid content (%). = 294 nm (about 300 nm). The dry film test results of Example 5 and Comparative Example 5 are as follows.

<5-1> Crack Comparison Experiment

This is the result of a crack comparison experiment under 120 ° C heat curing conditions.

Mixture of MTES and DMDES comparative example
5 Example 5-1 Example 5-2 Example 5-3 Example 5-4 Example 5-5 Example 5-6 Example 5-7 (expected degree of crosslinking) (3.0) (2.0) (2.7) (2.8) (2.85) (2.9) (2.95) (3.0) 120℃ x 1hr O O O O O O O O 120℃ x 2hr △ O O O O O O O 120℃ x 3hr X O O O O O O O 120℃ x 4hr X O O O O O O △

(Note: X = cracks, △ = fine cracks.)

<5-2> Crack comparison test

This is the result of a crack comparison test under 150 ° C heat curing conditions.

Mixture of MTES and DMDES comparative example
5 Example 5-1 Example 5-2 Example 5-3 Example 5-4 Example 5-5 Example 5-6 Example 5-7 (expected degree of crosslinking) (3.0) (2.0) (2.7) (2.8) (2.85) (2.9) (2.95) (3.0) 150℃ x 1hr X O O O O O O O 150℃ x 2hr X O O O O O O △ 150℃ x 3hr X O O O O △ △ X 150℃ x 4hr X O O △ △ △ △ X

(Note: X = cracks, △ = fine cracks)

<5-3> Pencil hardness measurement

This is the pencil hardness measurement result under 120 ° C. heat curing conditions.

Mixture of MTES and DMDES comparative example
5 Example 5-1 Example 5-2 Example 5-3 Example 5-4 Example 5-5 Example 5-6 Example 5-7 (expected degree of crosslinking) (3.0) (2.0) (2.7) (2.8) (2.85) (2.9) (2.95) (3.0) 120℃ x 1hr 8H 2B 3H 4H 4~5H 5H 5~6H 6H 120℃ x 2hr 9H 2B 3H 5H 5~6H 6H 6H 6~7H 120℃ x 3hr X 2B 4~5H 6H 6~7H 6~7H 6~7H 7H 120℃ x 4hr X H 6H 7H 7~8H 7~8H 8H 8H

(Note: X= not measurable.)

<5-4> Pencil hardness measurement

This is a pencil hardness measurement result under 150 ° C. heat curing conditions.

Mixture of MTES and DMDES comparative example
5 Example 5-1 Example 5-2 Example 5-3 Example 5-4 Example 5-5 Example 5-6 Example 5-7 (expected degree of crosslinking) (3.0) (2.0) (2.7) (2.8) (2.85) (2.9) (2.95) (3.0) 150℃ x 1hr X HB 5~6H 6H 6~7H 6~7H 6~7H 7H 150℃ x 2hr X H 6H 6~7H 7H 7H 7~8H 8H 150℃ x 3hr X H 6~7H 7~8H 7~8H 8H 8~9H X 150℃ x 4hr X H 7H 8H 8H 8~9H 8~9H X

(Note: X= not measurable.)

<5-5> Measurement of surface resistance (Ω/□)

These are the surface resistance (Ω/□) measurement results under 120°C heat curing conditions.

Mixture of MTES and DMDES comparative example
5 Example 5-1 Example 5-2 Example 5-3 Example 5-4 Example 5-5 Example 5-6 Example 5-7 (expected degree of crosslinking) (3.0) (2.0) (2.7) (2.8) (2.85) (2.9) (2.95) (3.0) 120℃ x 1hr E4.5 E5.7 E5.1 E5.0 E5.0 E5.0 E5.0 E4.8 120℃ x 2hr E8.7 E5.8 E5.1 E5.1 E5.0 E5.0 E4.9 E4.8 120℃ x 3hr X E5.8 E5.2 E5.2 E5.2 E5.1 E5.1 E5.0 120℃ x 4hr X E5.9 E5.5 E5.3 E5.3 E5.3 E5.3 E5.4

(Note: X= not measurable.)

<5-6> Measurement of surface resistance (Ω/□)

These are the surface resistance (Ω/□) measurement results under 150°C heat curing conditions.

Mixture of MTES and DMDES comparative example
5 Example 5-1 Example 5-2 Example 5-3 Example 5-4 Example 5-5 Example 5-6 Example 5-7 (expected degree of crosslinking) (3.0) (2.0) (2.7) (2.8) (2.85) (2.9) (2.95) (3.0) 150℃ x 1hr X E5.9 E5.3 E5.3 E5.3 E5.3 E5.3 E5.2 150℃ x 2hr X E5.9 E5.4 E5.4 E5.4 E5.3 E5.3 E5.4 150℃ x 3hr X E6.0 E5.5 E5.4 E5.4 E5.4 E5.5 X 150℃ x 4hr X E6.3 E5.7 E5.6 E5.5 E5.5 E5.6 X

(Note: X= not measurable.)

In the following <5-7> and <5-8>, the compositions of Example 5 and Comparative Example 5 prepared for the storage stability test were re-coated at intervals of 1 week for 4 weeks and 7 days immediately after preparation to 120 ° C. Heat and harden under conditions of x 2 hr. Changes in physical properties of the composition are measured by measuring the hardness and surface resistance of each specimen.

<5-7> Storage test

It shows the storage test results of Example 5 and Comparative Example 5, and is a hardness measurement value (120 ° C x 2 hr).

Mixture of MTES and DMDES comparative example
5 Example 5-1 Example 5-2 Example 5-3 Example
5-4 Example 5-5 Example 5-6 Example 5-7 (expected degree of crosslinking) (3.0) (2.0) (2.7) (2.8) (2.85) (2.9) (2.95) (3.0) coating after manufacturing 9H 2B 3H 5H 5~6H 6H 6~7H 6~7H Re-coating after 1 week X 2B 3H 5H 5~6H 6H 6H 6~7H Re-coating after 2 weeks X 2B 3H 5H 5~6H 6H 6H 6~7H Re-coating after 3 weeks X 2B 3H 4~5H 6H 5~6H 5~6H 5~6H Recoating after 4 weeks X 2B 3H 4H 4~5H 5H 5H 5H

(Note: X= not measurable.)

<5-8> Storage test results

It shows the storage test results of Example 5 and Comparative Example 5, and is a surface resistance measurement value (120 ° C x 2 hr).

Mixture of MTES and DMDES comparative example
5 Example 5-1 Example 5-2 Example 5-3 Example
5-4 Example 5-5 Example
5-6 Example 5-7 (expected degree of crosslinking) (3.0) (2.0) (2.7) (2.8) (2.85) (2.9) (2.95) (3.0) coating after manufacturing E8.7 E5.8 E5.1 E5.1 E5.0 E5.0 E4.9 E4.8 Re-coating after 1 week E 12.5 E6.2 E5.2 E5.1 E5.0 E5.2 E4.9 E4.8 Re-coating after 2 weeks X E6.5 E5.4 E5.3 E5.2 E5.2 E5.0 E5.0 Re-coating after 3 weeks X E6.9 E5.7 E5.4 E5.4 E5.3 E5.2 E5.2 Recoating after 4 weeks X E7.2 E6.2 E5.7 E5.6 E5.5 E5.4 E5.4

(Note: X= not measurable.)

The following <5-9> and <5-10> are for testing the change over time of the dry film of Example 5 and Comparative Example 5. The prepared compositions of Experimental Example were coated and cured under conditions of 120°C x 2 hr and 150°C x 2 hr. After each specimen was stored in an oven at a temperature of 80 ° C. for 7 days (hours), the presence or absence of cracks and surface resistance were measured.

<5-9> Time-lapse change of dry coating films of Example 5 and Comparative Example 5

The heat-drying conditions show the test results of the dry film change over time of Example 5 and Comparative Example 5 at 120 ° C. x 2 hr. The theoretical value of dry film thickness is the result of measurement after storage at 294 nm (about 300 nm), 80 ° C oven x 7 days (168 hr).

Mixture of MTES and DMDES comparative example
5 Example 5-1 Example 5-2 Example 5-3 Example 5-4 Example 5-5 Example 5-6 Example 5-7 (expected degree of crosslinking) (3.0) (2.0) (2.7) (2.8) (2.85) (2.9) (2.95) (3.0) pencil hardness after coating 9H 2B 3H 5H 5~6H 6H 6H 6~7H 7 days later X H 5~6H 6~7H 6~7H 7H 7~8H 7~8H Crack (after 7 days) X O O O O O O O surface resistance
(Ω/□) after coating E8.7 E5.8 E5.1 E5.1 E5.0 E5.0 E4.9 E4.8 7 days later X E6.0 E5.4 E5.4 E5.3 E5.3 E5.2 E5.3

(Note: X = unmeasurable, cracks, △ = fine cracks, O = no cracks (visual observation))

<5-10> Dry coating film over time change test

The heat-drying conditions show the test results of the dry film change over time of Example 5 and Comparative Example 5 at 150 ° C. x 2 hr. The theoretical value of dry film thickness is the result of measurement after storage at 294 nm (about 300 nm), 80 ° C oven x 7 days (168 hr).

Mixture of MTES and DMDES comparative example
5 Example 5-1 Example 5-2 Example 5-3 Example
5-4 Example 5-5 Example 5-6 Example 5-7 (expected degree of crosslinking) (3.0) (2.0) (2.7) (2.8) (2.85) (2.9) (2.95) (3.0) pencil hardness after coating X H 6H 6~7H 7H 7H 7~8H 8H 7 days later X H 6~7H 7~8H 8H 8H 8~9H 8~9H Crack (after 7 days) X X O O O O O O surface resistance
(Ω/□) after coating X E5.9 E5.4 E5.4 E5.4 E5.3 E5.3 E5.4 7 days later X E6.0 E5.6 E5.7 E5.7 E5.6 E5.7 E5.8

(Note: X = unmeasurable, cracks, △ = fine cracks, O = no cracks (visual observation))

In the binder composition, the composition of Example 5 showed excellent effects in most physical properties and stability compared to Comparative Example 5, and in particular, the compositions of Examples 5-4 to 5-6 showed the most excellent physical properties. Therefore, the solid content of DMDEs is preferably 5 to 15 g based on parts by weight of 100 g of MTES solid content.

As a result of the above experiment, in preparing a hydrolyzed composition of a conductive polymer aqueous dispersion (Pedot-PSSA aqueous dispersion) and an inorganic binder, a silane-based compound, rather than using a tetrafunctional TEOS, a trifunctional silane with an alkyl group substituted The composition prepared by mixing with the inorganic material had low dehydration condensation reactivity, and thus the composition had excellent shelf life.

The inorganic conductive polymer composition prepared by mixing with the trifunctional silane-based inorganic material in which the alkyl group is substituted has lower reactivity than the inorganic conductive polymer composition prepared using the tetrafunctional group TEOS, so that the heat curing temperature for dehydration condensation is higher than that of the tetrafunctional group composition. A longer heat-curing time is required. If the curing time cannot be increased, the curing temperature must be increased.

When a dry film coated with an inorganic composition having excellent room temperature stability is subjected to heat curing under sufficient conditions, crack generation is suppressed, and consequently, the change in the dry film with time is small. The dry coating film of the mixed composition of MTES and DMDES was more stable than the composition using MTES alone, and at this time, the range of stable mixing ratio can be seen as 2,8 or more and 3.0 or less based on the degree of crosslinking. More preferably, the range of 2.9 is stable.

From the above experimental results, this composition has a surface resistance of 10_6 or less on the basis of curing at 150 degrees for 2 hours, a hardness of 7H or more, and a change in dry coating film over time after storage at 80 ° C for 168 hr. showed excellent physical properties compared to TEOS.

Claims (12)

water-based conductive polymer solution; bookbinder; and a solvent;
The binder is a mixture of MTES (methyl triethoxy silane) and DMDES,
The binder is mixed with 5 to 15 parts by weight of DMDES solids based on 100 parts by weight of MTES solids. delete delete According to claim 1,
The solvent is isopropanol (IPA) composition for forming a back electrode. According to claim 1,
The conductive polymer is a composition for forming a back electrode of Pedot-PSSA. According to claim 1,
20 to 30% by weight of the water-based conductive polymer solution; 2 to 5% by weight of a binder; and 65 to 75% by weight of a solvent for forming a back electrode composition. According to claim 1,
The solid content of the conductive polymer is 14 to 21 parts by weight based on 100 parts by weight of the binder solid content of the back electrode forming composition. a) preparing a mixed solution by mixing a binder and a solvent;
b) adding a conductive polymer solution to the solution; and
c) hydrolyzing the conductive polymer and the binder;
Step c) is a method for preparing a composition for forming a back electrode, wherein the reaction is performed for 24 hours or more. delete As a method for manufacturing a back electrode,
a) coating a substrate with the composition for forming a rear electrode of claim 1;
b) heating and curing the coated substrate; and
c) reacting the composition to have a three-dimensional network structure formed by a condensation reaction; According to claim 10,
Wherein step b) is heat curing at 110 to 130 ° C for 2 to 4 hours or 140 to 160 ° C for 1 to 3 hours. According to claim 10,
The back electrode is a method of manufacturing a back electrode having a pencil hardness of 7H or more and a surface resistance of 10_7 or less.