JP2006334816A - Conductive composite film - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a top-coated conductive composite film kept or enhanced in its conductive level and sharply enhanced in abrasion resistance and solvent resistance. <P>SOLUTION: The conductive composite film comprises: a base material; a conductive layer, which is composed of a polymer of pyrrole and/or a pyrrole derivative, formed on the base material; and a coating film with a thickness of 10-100 nm which covers the conductive layer and comprises a resin containing an acidic component. This conductive composite film has not only good conductivity but also, excellent abrasion resistance and solvent resistance. This conductive composite film is useful in various fields requiring dust adhesion preventing properties, static electricity shielding properties, etc. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a conductive composite film in which conductivity (surface resistance value) does not change or is improved by coating a conductive layer made of a polymer of pyrrole and / or a pyrrole derivative with a resin containing an acidic component.

Several patents are already known in which another layer is provided on a conductive layer and combined to give a new functionality.
A conductive sheet provided with a conductive layer or an antistatic layer on at least one surface thereof, wherein an ion barrier layer containing an inorganic ion exchanger is formed on the surface of the conductive layer or the antistatic layer. Sex sheets have been proposed. This is because when an antistatic sheet is used as a packaging material for electronic components, cations such as alkali metals that exhibit conductivity and acid ions such as halogen ions and sulfate ester ions that are counter ions are present in the electronic components. The purpose is to prevent damage such as rusting due to transition to. That is, by forming an ion barrier layer containing an inorganic ion exchanger on the surface of the conductive layer or antistatic layer, it is possible to prevent migration of various ions present in the conductive sheet and to eliminate damage to the packaged electronic components. (Patent Document 1).

In addition, it is a release film in which an antistatic layer having a surface resistivity of 1 × 10 ⁵ to 1 × 10 ¹² Ω / mouth is provided on one side of a polyester film, and a release layer is provided on the antistatic layer. Thus, a release film characterized by containing a conductive polymer obtained by polymerizing thiophene and / or a thiophene derivative in the antistatic layer is disclosed. This is related to a release film, which prevents charging during running and running, which was a problem of this conventional film, and release when used as a carrier film for molding in an adhesive film or a resin sheet. The purpose is to prevent charging failure formed on the layer (Patent Document 2).

Further, the surface of the conductive polymer made of polypyrrole on the substrate is 0.05 μm to 5.
A conductive layer is proposed which is coated with a thin layer of an oxygen gas barrier resin having a film thickness in the range of 0 μm and containing a high-molecular-weight ultraviolet absorber. The purpose is to prevent cleavage of the conjugated double bond by oxygen in the inside. That is, an increase in resistance value (decrease in electrical conductivity) due to breaking of a conjugated double bond of a conductive polymer is prevented, and even when left in the air for a long time, the change in resistance value is remarkably small and stable conductivity (Patent Document 3). However, in this case, the purpose is to reduce the increase in resistance value, and the resistance value actually increases.

The conventional technology as described above has been to add a functional performance that has not been heretofore or to try to improve it by forming a layer having another function on the conductive layer or the charged layer. However, in any case, since a layer having no conductive performance is provided on the conductive layer, in the state where these functional performances are given, the thickness of the new layer is also affected. There was a phenomenon in which the level of property (surface resistance value) was clearly reduced. This has led to the drawback of lowering the essential level of conductivity by imparting new performance.
Japanese Patent Laid-Open No. 2000-31808 (Legnos) JP 2000-52495 A (Teijin) Patent No. 2985698 (Achilles)

  The object of the present invention is to maintain or improve the level of conductivity originally held by the conductive layer, and to greatly improve the wear resistance and solvent resistance, and a conductive composite coated with a top coat. To provide a film.

  As a result of intensive studies to solve the above problems, the present inventors have surprisingly found that when the surface of the conductive layer is coated with a resin containing an acidic component, the conductivity (surface resistance value) is the initial conductivity. The present invention was completed by finding that the conductive composite film was not changed or improved as compared with the property level, and that the formed conductive composite film had good wear resistance and solvent resistance.

That is, the present invention
1. A base material, a conductive layer made of a polymer of pyrrole and / or a pyrrole derivative formed on the base material, and a coating layer having a thickness of 10 nm to 100 nm made of a resin containing an acidic component that covers the conductive layer A conductive composite film comprising:
2. The pyrrole and / or pyrrole derivative polymer is obtained by adding a monomer of pyrrole and / or a pyrrole derivative to an O / W type emulsion obtained by mixing and stirring an organic solvent, water, and an anionic surfactant, It consists of conductive fine particles obtained by oxidative polymerization of the monomer. The conductive composite film according to the description,
3. The covering layer has a thickness of 20 nm to 50 nm. Or 2. The conductive composite film according to the description,
It is about.

  According to the present invention, it is possible to provide a conductive composite film having good conductivity and excellent wear resistance and solvent resistance. The conductive composite film is useful in various fields that require dust adhesion prevention, electrostatic shielding, and the like.

The conductive fine particles prepared from pyrrole and / or a pyrrole derivative and an anionic surfactant used in the present invention do not use an acidic dopant and only an anionic surfactant in an amount that does not liberate. Since it is not used, unlike conventional conductive paints, it has excellent characteristics that it shows a resistance value independent of humidity and is not corrosive to metals due to liberation of acid. Although the anionic surfactant in the system is presumed to act as a dopant that lowers the resistance value, the amount thereof is extremely small with respect to the amount of the conductive polymer. The resistance value of the conductive layer prepared using 10 ⁷ ~
The range of 10 ¹⁰ Ω is not low. The reason why the conductive performance was maintained or improved when the conductive layer was coated with a resin having an acidic component this time is that the acidic component mixed in the resin plays a role of a dopant for the underlying conductive polymer. It is presumed that the resistance value of the conductive polymer itself was further reduced, thereby preventing the increase in resistance value due to the coating. Moreover, since this coating layer is a very thin film, it is thought that the influence of the lower conductive polymer layer reflects more strongly than the insulation performance by a coating layer.

The present invention relates to a conductive composite film in which a conductive layer composed of a polymer of pyrrole and / or a pyrrole derivative is coated with a resin containing an acidic component in order to impart wear resistance and solvent resistance. The present invention relates to a conductive composite film whose conductivity is maintained or improved.
In order to maintain or improve conductivity, it is considered necessary that the acidic component contained in the coating layer acts as a dopant. Therefore, the acidic component, particularly its type and acidity are considered important.

As said acidic component, the salt which shows an acid and acidity is preferable. Specific examples thereof include inorganic or organic acids and acidic salts, which are also used as dopants for improving conductivity.
Inorganic acids include hydrochloric acid, sulfuric acid, phosphoric acid, perchloric acid, and inorganic salts include aluminum chloride, ammonium chloride, sodium perchlorate, aluminum sulfate, sodium persulfate, ammonium persulfate, ammonium sulfate, phosphoric acid. Ammonium etc. are mentioned.
Organic acids and their salts include acetic acid, acetate, acetate, ethylamine hydrochloride, triethanolamine hydrochloride, methylamine hydrochloride, ethylamine hydrochloride, formic acid, formate, oxalic acid, oxalate, methanesulfonic acid Trifluoromethanesulfonic acid, benzenesulfonic acid, p-toluenesulfonic acid, anthraquinonesulfonic acid, naphthalenesulfonic acid, sulfosalicylic acid, n-dodecylbenzenesulfonic acid, allylsulfonic acid, alkyl acidic phosphate, and the like.
Preferable acidic components include hydrochloric acid, p-toluenesulfonic acid, alkyl acidic phosphate ester, and the like.
In addition, as said alkyl acidic phosphate ester, the monoalkyl ester of phosphoric acid, dialkyl ester, or these mixtures are mentioned, As alkyl, methyl, butyl, 2-ethylhexyl, stearyl, oleyl, and these 2 or more types of these A mixture etc. are mentioned.

The acidity is preferably adjusted when preparing a solution in which a resin, an acidic component, and, if desired, an additive and the like are dissolved in water or a suitable organic solvent for forming the coating layer.
For example, when the solution is an aqueous solution, it is preferable to adjust the pH value to a range of 1 to 5. In the case of an organic solution, the pH value is 1 although it cannot be indicated by pH. It is preferable to set the acidity to be in the range of ˜5.

  The thickness of the formed coating layer is extremely important from the viewpoint of imparting abrasion resistance and solvent resistance and maintaining or improving conductivity, and a thickness of 10 to 100 nm is necessary after drying. is there. In particular, a thickness of 20 to 50 nm is more preferable. If it is 10 nm or less, this coating layer does not provide “abrasion resistance, solvent resistance” or the like for the purpose of improvement, and if it is 100 nm or more, the influence of the coating layer as an insulating material increases and the surface resistance increases ( A decrease in conductive performance is inevitable.

  As a resin used for forming the coating layer, any of a water-soluble resin and a water-insoluble resin can be used. Examples of water-soluble resins include polyvinyl alcohol (PVA) resins such as polyvinyl alcohol and polyethylene vinyl alcohol, water-soluble polyester resins, alkyl vinyl ether resins, maleic acid copolymer resins, polyvinyl pyrrolidone resins, cellulose resins, and water-soluble resins. Examples include alkyd resins and non-cellulose water-soluble polysaccharides. Non-water-soluble resins include polypropylene, polyethylene, polyethylene oxide, polyvinyl alcohol, polyacrylamide, polyvinyl acetal, polyvinyl pyrrolidone, polyvinyl chloride, polyester, polycarbonate, alkyd resin, amino resin, epoxy resin, polyurethane, acrylate or methacrylate. Polymer, ethylene- (meth) acrylate copolymer, ethylene- (meth) acrylic acid copolymer, acrylic resin such as ethylene-acrylonitrile copolymer, styrene-maleic anhydride copolymer, polyethylene-unsaturated carboxylic acid Graft copolymer, modified resin such as polypropylene-unsaturated carboxylic acid graft copolymer, ethylene-vinyl acetate copolymer, ethylene-methacrylic acid-acrylonitrile terpolymer Various thermoplastic resins or thermosetting resins related to vinyl polymers, binary or ternary copolymers, graft copolymers, block copolymers, such as polymethyl methacrylate, cellulose, and polyvinyl acetate It is done.

However, when an organic solvent is used, since the conductive fine particles themselves are hydrophobic, some of the conductive fine particles may fall off depending on the coating (coating) conditions, resulting in poor uniformity. Therefore, in order to prevent such non-uniformity, it is preferable to prepare an aqueous solution using a water-soluble resin that can be prepared as an aqueous solution. As the water-soluble resin to be used, polyvinyl alcohol, polyethylene vinyl alcohol, and the like are preferable. In addition, in order to improve the strength of the surface, it is possible to give a crosslinked structure by adding isocyanate, melamine or the like.

  By applying a solution prepared by dissolving the above-listed resin, acidic components and, if necessary, additives in water or an appropriate organic solvent onto the conductive layer, and heating and drying as necessary. A coating layer can be formed.

  The pyrrole and / or pyrrole derivative polymer used in the present invention is composed of conductive fine particles, and the conductive fine particles are formed by mixing and stirring an organic solvent, water, and an anionic surfactant. It is produced by adding a monomer of pyrrole and / or a pyrrole derivative to a W-type emulsion and subjecting the monomer to oxidative polymerization.

  Examples of the pyrrole and / or pyrrole derivative include pyrrole, N-methylpyrrole, N-ethylpyrrole, N-phenylpyrrole, N-naphthylpyrrole, N-methyl-3-methylpyrrole, N-methyl-3-ethylpyrrole, N-phenyl-3-methylpyrrole, N-phenyl-3-ethylpyrrole, 3-methylpyrrole, 3-ethylpyrrole, 3-n-butylpyrrole, 3-methoxypyrrole, 3-ethoxypyrrole, 3-n-propoxy Pyrrole, 3-n-butoxypyrrole, 3-phenylpyrrole, 3-toluylpyrrole, 3-naphthylpyrrole, 3-phenoxypyrrole, 3-methylphenoxypyrrole, 3-aminopyrrole, 3-dimethylaminopyrrole, 3-diethylaminopyrrole , 3-diphenylaminopyrrole, 3-methyl Le phenylamino pyrrole, 3-phenyl naphthyl amino pyrrole, and the like. Particularly preferred is pyrrole.

Various anionic surfactants can be used, but those having a plurality of hydrophobic ends (for example, those having a branched structure in a hydrophobic group or those having a plurality of hydrophobic groups) are preferred. By using such an anionic surfactant having a plurality of hydrophobic ends, stable micelles can be formed.
Among anionic surfactants having multiple hydrophobic ends, di-2-ethylhexyl sodium sulfosuccinate (4 hydrophobic ends), di-2-ethyloctyl sodium sulfosuccinate (4 hydrophobic ends) and branched type Alkyl benzene sulfonate (two hydrophobic ends) can be preferably used.

  The amount of the anionic surfactant in the reaction system is preferably less than 0.2 mol, more preferably 0.05 mol to 0.15 mol, with respect to 1 mol of pyrrole and / or pyrrole derivative monomer. If the amount is less than 0.05 mol, the yield and the dispersion stability are lowered. On the other hand, if the amount is 0.2 mol or more, the resulting conductive fine particles may have a conductivity humidity dependency.

  In the production, the organic solvent forming the organic phase of the emulsion is preferably hydrophobic. Especially, toluene and xylene which are aromatic organic solvents are preferable from the viewpoint of the stability of the O / W emulsion and the affinity with the pyrrole monomer. Although the polypyrrole can be polymerized with an amphoteric solvent, it becomes difficult to separate the organic phase and the aqueous phase when the produced conductive fine particles are recovered.

The ratio of the organic phase to the aqueous phase in the emulsion is preferably 75% by volume or more in the aqueous phase. When the water phase is 20% by volume or less, the amount of pyrrole monomer dissolved is reduced and the production efficiency is deteriorated.

  Examples of the oxidizing agent used in the production include inorganic acids such as sulfuric acid, hydrochloric acid, nitric acid and chlorosulfonic acid, organic acids such as alkylbenzenesulfonic acid and alkylnaphthalenesulfonic acid, potassium persulfate, ammonium persulfate and peroxidation. Peroxides such as hydrogen can be used. These may be used alone or in combination of two or more. Polypyrrole can be polymerized even with a Lewis acid such as ferric chloride, but the produced particles may aggregate and the polypyrrole may not be finely dispersed. Particularly preferred oxidizing agents are persulfates such as ammonium persulfate.

  The amount of the oxidizing agent in the reaction system is preferably 0.1 mol or more and 0.8 mol or less, more preferably 0.2 to 0.6 mol with respect to 1 mol of the monomer of pyrrole and / or pyrrole derivative. . If the amount is less than 0.1 mol, the degree of polymerization of the monomer decreases, making it difficult to separate and collect the conductive fine particles. Stability and transparency of the coating deteriorate.

The method for producing the conductive fine particles is performed, for example, in the following steps:
(A) a step of preparing an emulsion by mixing and stirring an anionic surfactant, an organic solvent and water;
(B) a step of dispersing a monomer of pyrrole and / or a pyrrole derivative in an emulsion, (c) a step of oxidative polymerization of the monomer to cause polyanol to contact and adsorb on an anionic surfactant,
(D) A step of separating the organic phase and collecting the conductive fine particles.

  Each of the above steps can be performed using means known to those skilled in the art. For example, the mixing and stirring performed at the time of preparing the emulsion is not particularly limited. For example, a magnetic stirrer, a stirrer, a homogenizer, or the like can be selected as appropriate. The polymerization temperature is 0 to 25 ° C, preferably 20 ° C or less. If the polymerization temperature exceeds 25 ° C., side reactions occur, which is not preferable.

  When the oxidative polymerization reaction is stopped, the reaction system is divided into an organic phase and an aqueous phase. At this time, unreacted monomers, oxidizing agents and salts remain dissolved in the aqueous phase. When the organic phase is separated and recovered and washed several times with ion exchange water, polypyrrole fine particles dispersed in an organic solvent can be obtained.

  The conductive fine particles obtained by the above production method are fine particles mainly composed of pyrrole and / or a pyrrole derivative and containing an anionic surfactant. And the characteristic is that it can disperse | distribute in a fine particle size and an organic solvent.

  The particle diameter of the conductive fine particles is specifically 1 to 30 nm. This particle size is much smaller than the particle size of several hundred nm that the conventional conductive fine particles have. Further, the conductive fine particles have a narrow particle size distribution close to monodispersion in which 90% or more of all the fine particles are included in the range of ± 5 nm of the average particle size. This is different from conventional conductive fine particles having a large width. This very small particle size is considered to be one of the factors of long-term dispersion stability of the conductive fine particles. Further, since the particle size is small, it is considered that the coating film has transparency when it is made a conductive paint.

The conductive fine particles obtained by the method described above have high dispersion stability in an organic solvent. Therefore, after dispersing conductive fine particles in an organic solvent, the conductive layer can be easily formed on the base material by applying to the base material, heating as necessary, and drying. The organic solvent to be used is not particularly limited as long as it does not damage the conductive fine particles and can disperse the conductive fine particles. Preferably, aromatic hydrocarbons such as benzene, toluene, and xylene are listed. It is done. Furthermore, it is also possible to add a resin such as a dispersion stabilizer, a thickener, and an ink binder to the dispersion according to the needs of the application and application object. Moreover, the coating method to a base material is not specifically limited, either, For example, it can print or coat using a gravure printer, an inkjet printer, a dipping, a spin coater, a roll coater etc. The conductive layer thus obtained exhibits a resistance value of 10 ⁷ to 10 ¹⁰ Ω.

  The substrate used in the present invention is not particularly limited, but is not limited to polyester resin such as polyethylene terephthalate, acrylic resin such as polymethyl methacrylate, polypropylene resin, polycarbonate resin, polystyrene resin, polyvinyl chloride resin, polyamide resin, polyimide resin, glass Etc.

  The conductive composite film manufactured by the method described above is used in the field of optical films such as displays (prevention of dust adhesion), the surface protection field of display devices (prevention of dust adhesion), such as liquid crystal and PDP, and the appearance parts of electronic devices. It can be used in fields such as the field of protective films (prevention of dust adhesion), the field of template films such as resist films and polarizing films (prevention of dust adhesion), and the field of CRT / liquid crystal displays (electrostatic shield).

  EXAMPLES Next, although an Example demonstrates this invention still in detail, this invention is not limited to an Example. The measurement and test methods used in this example are as follows.

表１中のポリピロール系塗料は以下の方法により作成した。
スルホコハク酸ジ−２−エチルヘキシルナトリウム１．５ｍｍｏｌをトルエン５０ｍＬに溶解し、さらにイオン交換水１００ｍＬを加え２０℃に保持しつつ乳化するまで攪拌した。得られた乳化液にピロールモノマー２１．２ｍｍｏｌを加え、３０分攪拌し、次いで０．１２Ｍ過硫酸アンモニウム水溶液５０ｍＬ（６ｍｍｏｌ相当）を少量ずつ滴下し、４時間反応を行った。反応終了後、有機相を回収し、イオン交換水で数回洗浄して、トルエン中に黒色の導電性微粒子が分散した状態のポリピロール系塗料を得た。
１〜５までの導電性塗料をスピンコーターを用いてガラス基板に、導電層の厚みが０．１μｍとなるように塗布し、１４０℃で５分間乾燥させた。 [Examples and Comparative Examples]
The conductive layer and the coating layer were prepared by the following method.
1, conductive layer Table 1

The polypyrrole paint in Table 1 was prepared by the following method.
1.5 mmol of di-2-ethylhexyl sodium sulfosuccinate was dissolved in 50 mL of toluene, and further 100 mL of ion-exchanged water was added and stirred until emulsification was maintained at 20 ° C. To the obtained emulsion, 21.2 mmol of pyrrole monomer was added and stirred for 30 minutes, and then 50 mL (corresponding to 6 mmol) of a 0.12 M aqueous ammonium persulfate solution was added dropwise little by little and reacted for 4 hours. After completion of the reaction, the organic phase was recovered and washed several times with ion-exchanged water to obtain a polypyrrole paint with black conductive fine particles dispersed in toluene.
1 to 5 conductive coatings were applied to a glass substrate using a spin coater so that the thickness of the conductive layer was 0.1 μm, and dried at 140 ° C. for 5 minutes.

※１ 塩酸は０．１Ｍに調整したものを使用した。
※２ 大日本インキ工業（株)製の塗料用アミノ樹脂溶液である（アミノ樹脂、イソブ
チルアルコ
ール他混合溶媒溶液）。
※３ 大日本インキ工業（株)製の塗料用硬化促進剤（アルキル酸性リン酸エステル混
合溶媒溶液
）。 2. Coating layer The topcoat agent to be applied on the conductive layer is prepared by dissolving the amount of the topcoat resin and acidic components shown in Table 2 in water for A1 to E in Table 2, and the solid content is It was prepared to be 3%. Similarly, F and G were diluted with isopropyl alcohol so that the solid content was 3% to prepare a topcoat agent.
Table 2

* 1 Hydrochloric acid adjusted to 0.1M was used.
* 2 Amino resin solution for paints manufactured by Dainippon Ink Industries, Ltd. (amino resin, isobutyl alcohol and other mixed solvent solutions).
* 3 A curing accelerator for coatings (alkyl acid phosphate mixed solvent solution) manufactured by Dainippon Ink & Chemicals, Inc.

The topcoat agent thus prepared was applied to the glass on which the conductive layer was formed using a spin coater, and dried at 140 ° C. for 3 minutes to coat the conductive layer with the coating layer. The thickness of the coating layer was controlled by the rotation speed of the spin coater. Table 3 shows the thickness and surface resistance value of each coating layer.
Table 3

3. Measurement / Evaluation Measurement / evaluation was performed as follows.
(1) Thickness The thickness of the coating layer was measured by using an optical thin film measuring instrument (FilmTek 3000, manufactured by SCI).
(2) Surface resistance value Surface resistance value is measured by Diains Co., Ltd. resistivity meter Hiresta UP, MCP-HT450
It measured using. The measurement was performed by the two-terminal method, and a UA probe (MCP-HTP11) was used.
(3) Resistance value change The resistance value change after coating the top coat was measured by measuring the resistance value before and after coating, and the difference was not allowed to increase in resistance value by more than half digits. And other things were good.
(4) Abrasion resistance
A friction test was carried out in accordance with JIS L 0849 “Test method for dyeing fastness to friction”, and the transfer of the paint onto cotton cloth after 100 times of vibration at a load of 200 g was compared and evaluated. As evaluation criteria, evaluation was made with ○ as no coloration on the cotton cloth, Δ as slight coloration, and × as coloration due to complete transfer of the paint.
(5) Solvent resistance Abrasion test was conducted with a cotton cloth soaked with IPA in accordance with JIS L 0849 “Test method for fastness to dyeing to friction” in the same manner as abrasion resistance. The evaluation was performed according to the same criteria as the above-mentioned wear resistance.

4. Evaluation results As shown in the examples and comparative examples, the conductivity was maintained or improved by coating a conductive layer made of a polymer of pyrrole and / or a pyrrole derivative with a resin containing an acidic component. Moreover, when the thickness of the coating layer was 5 nm, the intended “abrasion resistance and solvent resistance” could not be obtained. On the other hand, when the thickness was 150 nm, the conductivity decreased.
In addition, the maintenance or improvement of the conductivity shown above is observed when a similar coating layer is formed using another conductive material (thiophene paint, aniline paint, ATO paint, ITO paint). Therefore, it was shown that the effect of maintaining or improving conductivity is observed only when a conductive layer made of a polymer of pyrrole and / or a pyrrole derivative is used.

Claims (3)

A base material, a conductive layer made of a polymer of pyrrole and / or a pyrrole derivative formed on the base material, and a coating layer having a thickness of 10 nm to 100 nm made of a resin containing an acidic component that covers the conductive layer A conductive composite film comprising: The pyrrole and / or pyrrole derivative polymer is obtained by adding a monomer of pyrrole and / or a pyrrole derivative to an O / W type emulsion obtained by mixing and stirring an organic solvent, water, and an anionic surfactant, The conductive composite film according to claim 1, comprising conductive fine particles obtained by oxidative polymerization of the monomer. The conductive composite film according to claim 1, wherein the coating layer has a thickness of 20 nm to 50 nm.