JP2010177259A - Transfer paper and method of manufacturing the same, and method of manufacturing functional thin film - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a transfer paper on which a pattern formation layer having excellent use efficiency of a conductive material can be efficiently formed and which can have the pattern formation layer and an overcoat layer transferred to a flexible film substrate, to provide a manufacturing method of the transfer paper, and to provide a manufacturing method of a functional thin film using the transfer paper. <P>SOLUTION: The manufacturing method of the transfer paper includes: a pattern formation layer forming process of forming the pattern formation layer by supplying a liquid for pattern formation layer which contains metal particulates each having a surface coated with a dispersion stabilizer, a polymer component, and a compound capable of capturing the dispersion stabilizer onto a transfer paper base having, on a base paper surface, a slowly water-soluble remoistenable adhesive layer and a quickly water-soluble remoistenable adhesive layer; a heating process of heating the transfer paper base having the pattern formation layer formed; and an overcoat layer forming process of forming the overcoat layer on the pattern formation layer. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a transfer sheet on which a conductive pattern for a thin film element is formed, a method for manufacturing the transfer sheet, and a method for manufacturing a functional thin film.

The printed wiring board plays an important role in satisfying the electrical and mechanical specification characteristics of electronic devices. Conventionally, as a substrate serving as a base of a printed wiring board, for example, an insulator such as glass, silicone wafer, ceramic, quartz, or sapphire is used, and various conductive patterns are formed on the substrate. As a method for forming such a conductive pattern, (1) a step of providing a thin film conductive material on an insulator by a method such as vacuum deposition, and (2) a step of applying a photoresist with a photosensitive resin or the like. (3) a step of exposing using a separately prepared photomask pattern, (4) a step of developing the pattern portion by removing the resist other than the pattern portion, (5) dry etching, wet etching, electrolytic etching, etc. A desired conductive pattern was formed by the step of removing the conductive material other than the pattern portion by the method and (6) the step of removing the resist.
The method for forming the conductive pattern requires at least six steps. In addition, since the manufacturing method is to delete the thin film formed on the entire surface of the substrate, the utilization efficiency of the material is poor, and a waste liquid treatment process accompanying the thin film deletion is also required. Furthermore, since it is necessary to separately prepare various masks for obtaining a desired pattern for each pattern, a complicated process has to be taken.

In recent years, electronic devices have been required to have specifications such as downsizing, weight reduction, and resistance to cracking. Further, by satisfying high specifications such as flexibility, bendability, and elasticity, it is expected to improve the performance and convenience of portable devices and image display devices. Furthermore, development to various application devices such as electronic paper and attachable image display devices is being promoted.
From such a background, a manufacturing method of a semiconductor device thin film composed of a thin film transistor (TFT) on a flexible film substrate has attracted attention. This semiconductor device thin film functions various application devices using printed wiring and semiconductor characteristics. Since the manufacturing process of the semiconductor device thin film goes through a harsh environment such as high temperature processing and solvent processing, there is a problem that it is difficult to form printed wiring and TFT on a flexible film substrate having low heat resistance and solvent resistance. is there.

For this reason, a separation layer is provided on the surface of a heat-resistant solid substrate such as a glass substrate, and the printed wiring formed on the separation layer and various element device thin films having semiconductor properties are separated from the separation substrate from the separation substrate. However, a method of transferring onto a flexible film has been proposed.
However, although this proposed method can form a device on a flexible film, the utilization efficiency of a material for obtaining a conductive pattern is poor, and a waste liquid treatment process associated with thin film removal is also required. Moreover, it has not led to a fundamental solution to the problem that it is necessary to separately prepare various masks for obtaining a desired pattern for each pattern.

Therefore, a method for directly forming a conductive pattern on a flexible film using a pattern portion forming method such as an ink jet method, a screen printing method, or a micro contact printing method has been proposed as a means for solving the above-described problems. Among these, the method using the ink jet technology used in the printer is particularly expected because the pattern can be directly formed without separately preparing a mask and a fine convex stamp base material necessary for each pattern. Has been sent.
In the inkjet method, a liquid repellent treatment is performed on the surface of the flexible film to form a region having a high affinity and a region having a low affinity for ink containing a conductive material, and a conductive ink pattern is formed in the region having a high affinity. The method of forming is common. In addition, a method of forming a conductive pattern on a flexible film subjected to various surface treatment modification treatments has been attempted. For example, a method has been proposed in which a hydrophilic graft polymer is formed on the entire surface of a flexible film, and a conductive material is formed on the surface of the flexible film in a pattern using an inkjet technique (see Patent Document 1).
In addition, a silane coupling agent (organosilicon compound) or thiol compound is formed on the substrate by spin coating, dipping, etc., and a liquid repellent treatment is applied to selectively remove the surface modification compound in the pattern area by light irradiation. A method of forming a conductive pattern has been proposed (see Patent Document 2).
By forming the conductive pattern by these methods, the utilization efficiency of the material is remarkably improved, and a desired pattern can be formed without a mask.

  However, in these proposals, it is necessary to use a limited combination of flexible film and material, which is limited to a flexible film having a surface modification. Further, in order to use the conductive pattern as the switching electrode circuit wiring, it is necessary to provide at least an insulating layer film on the pattern, and it is difficult to practically apply to thin film elements. Furthermore, it is said that the bonding state between the conductive pattern forming portion material and the interface between the binder resin, which is a polymer component, is greatly involved in the conductivity. However, these points have not yet been fully studied. There is no current situation.

  An object of the present invention is to solve various problems in the prior art and achieve the following objects. That is, the present invention can efficiently form a pattern forming layer with good utilization efficiency of the conductive material without using a mask separately prepared for each pattern or a dedicated transfer substrate, and the pattern forming layer and the overcoat. It is an object of the present invention to provide a transfer sheet capable of transferring a layer to a flexible film substrate, a method for manufacturing the transfer sheet, and a method for manufacturing a functional thin film using the transfer sheet.

Means for solving the problems are as follows. That is,
<1> Metal fine particles having a surface coated with a dispersion stabilizer, a polymer component, and a dispersion stabilizer on a transfer paper base material including a slow water re-wetting paste layer and a fast water-soluble re-wetting paste layer on the base paper surface A pattern forming layer forming step of forming a pattern forming layer by applying a liquid for a pattern forming layer containing a compound capable of capturing
A heating step of heating the transfer paper substrate on which the pattern forming layer is formed;
An overcoat layer forming step of forming an overcoat layer on the pattern forming layer;
A transfer sheet manufacturing method characterized by comprising:
<2> The method for producing a transfer paper according to <1>, wherein the metal fine particles are at least one selected from gold, nickel, copper, platinum, palladium, silver, and alloys thereof.
<3> The dispersion stabilizer is a compound having a group capable of coordinating with a metal element, and the group capable of coordinating with the metal element includes a group containing a nitrogen atom, a group containing an oxygen atom, and a sulfur atom. The transfer paper manufacturing method according to any one of <1> to <2>, wherein the transfer paper is any one of the groups included.
<4> The method for producing a transfer paper according to any one of <1> to <3>, wherein the dispersion stabilizer is desorbed from the metal fine particles by heating and becomes a dopant of a polymer component.
<5> The method for producing a transfer paper according to any one of <1> to <4>, wherein the polymer component is a π-conjugated polymer compound.
<6> The method for producing a transfer paper according to any one of <1> to <5>, wherein the compound capable of trapping the dispersion stabilizer is either an acid anhydride or a derivative thereof.
<7> The method for producing a transfer paper according to any one of <1> to <6>, wherein the pattern forming layer is formed by an inkjet method.
<8> A transfer sheet manufactured by the transfer sheet manufacturing method according to any one of <1> to <7>.
<9> The transfer paper according to <8>, wherein the Beck type smoothness of the transfer paper is 1,000 seconds or more.
<10> Transfer paper for transferring a laminated film including a pattern forming layer and an overcoat layer to a transfer target,
The transfer sheet according to any one of <8> to <9>, wherein the transfer target is a flexible film subjected to a gas barrier property treatment.
<11> Water is applied to the transfer paper according to any one of <8> to <10> to dissolve the adhesive layer and contact the transfer paper, thereby overcoating the pattern forming layer on the transfer paper. It is a method for producing a functional thin film, comprising at least a transfer step of transferring a laminated film including a coat layer to a flexible film subjected to a gas barrier treatment.
<12> The method for producing a functional thin film according to <11>, including a circuit pattern formation layer forming step of forming a circuit pattern formation layer on the laminated film.
<13> The method for producing a functional thin film according to any one of <11> to <12>, wherein the transfer step is repeated a plurality of times and laminated on the laminated film.

  According to the present invention, conventional problems can be solved, and without using a separately prepared mask or dedicated transfer base material for each pattern, a pattern forming layer with good utilization efficiency of the conductive material can be formed, A transfer paper capable of transferring the pattern forming layer and the overcoat layer to a flexible film substrate, a method for producing the transfer paper, and a method for producing a functional thin film using the transfer paper can be provided.

FIG. 1 is a diagram showing an example of a transfer paper substrate used in the present invention. FIG. 2 is a diagram showing an example of the transfer paper of the present invention. FIG. 3 is a conceptual diagram showing an action mechanism during heating in the transfer paper of the present invention. FIG. 4 is a schematic process diagram showing an example in the case of continuously producing the transfer paper of the present invention.

(Transfer paper manufacturing method)
The method for producing a transfer paper of the present invention includes a pattern forming layer forming step, a heating step, and an overcoat layer forming step, and further includes other steps as necessary.

<Pattern forming layer forming step>
The pattern forming layer forming step includes a fine metal particle having a surface coated with a dispersion stabilizer, a polymer component on a transfer paper base material including a slow water re-wetting paste layer and a fast water-soluble re-wetting paste layer on the base paper surface. And forming a pattern forming layer by applying a liquid for a pattern forming layer containing a compound capable of trapping the dispersion stabilizer.

-Transfer paper substrate-
The transfer paper base has a base paper, a slow water re-wetting paste layer and a fast water-soluble re-wetting paste layer on the base paper surface, and further has other layers as necessary.

There is no restriction | limiting in particular as said base paper, According to the objective, it can select suitably, For example, what made paper of natural pulp, such as a conifer and a hardwood, a mixture of this natural pulp and a synthetic pulp, etc. are mentioned.
In the pulp slurry obtained after beating the pulp that is the raw material of the base paper, if necessary, various additives such as filler, dry paper strength enhancer, sizing agent, wet paper strength enhancer, fixing agent, A pH adjuster, other chemicals, etc. are added.
The pulp slurry is made using a paper machine such as a hand paper machine, a long paper machine, a round paper machine, a twin wire machine, or a combination machine, and then dried to produce a base paper. If desired, surface sizing is performed either before or after the drying.

Examples of the material constituting the slow water re-wetting paste layer include water-soluble resins such as soluble starch, carboxymethyl cellulose, polyvinyl alcohol, dextrin, and gum arabic for suppressing water absorption. These may be used individually by 1 type and may use 2 or more types together.
Examples of the material constituting the quick water-soluble re-wetting paste layer include synthetic water-soluble adhesives such as yellow dextrin or carboxymethyl cellulose (CMC), carboxy-modified polyvinyl alcohol, carboxymethyl cellulose; oxidized starch, esterified starch, enzyme-modified starch , Natural water-soluble adhesives such as cold water-soluble starch obtained by flash drying them; hydrophobic resins such as styrene-butadiene copolymers, styrene-acrylic copolymers, ethylene-vinyl acetate copolymers An emulsion etc. are mentioned. These may be used individually by 1 type and may use 2 or more types together.

Here, FIG. 1 is a diagram showing an example of a transfer paper base material 10 used in the present invention. The transfer paper base 10 has three types of coat layers 13, 14, 15 on a base paper 12. In addition, 11 in FIG. 1 is a backcoat layer.
The base paper 12 is a no-size base paper made from hardwood or the like, and the first coat layer 13 is formed by coating the base paper 12 with the first coat layer coating solution. Thereby, the smoothness of the base paper 12 is improved, which contributes to the improvement of the smoothness of the transfer paper substrate 10 shown in FIG.
The first coating layer coating solution may contain pigments such as clay, light calcium carbonate, calcium bicarbonate, various latexes, lubricants, and water retention agents. The second coat layer 14 on the first coat layer 13 is composed of a slow water re-wetting paste layer, and the third coat layer 15 is composed of a fast water-soluble re-wetting paste layer.
Controlling the wettability of the ink droplets of the pattern forming layer liquid (ink liquid) discharged by the ink jet method and the surface of the third coat layer 15 with the fast water-soluble rewet paste composition in the third coat layer 15. It becomes possible. Similarly, the wettability between the surface of the third coat layer 15 and the ink droplets can also be controlled by adjusting the composition of the pattern forming layer liquid (ink liquid). The formation layer 16 and the overcoat layer 17 can be formed satisfactorily.

When the base paper 12 is made, the transfer paper base shown in FIG. 1 is made by making the base paper 12 with a Yankee paper machine having a single large-diameter dryer in the drying section and highly polished on the dryer surface. This contributes to improving the smoothness of the surface of the material 10 and can improve the smoothness of the transfer paper 20 of the present invention shown in FIG.
The method for applying the first coat layer to the third coat layer to the base paper 12 made by a Yankee machine is not particularly limited and can be appropriately selected according to the purpose. For example, a blade coater, an air knife coater, The coating is preferably performed on one side of the base paper 12 made by a Yankee machine using an on-machine or an off-machine coater provided with a coating device such as a roll coater, brush coater, curtain coater, champreg coater, bar coater or the like.
In addition, after providing the first coat layer to the third coat layer, in order to further impart smoothness to the transfer paper substrate, a mild treatment is performed by a surface treatment device such as a super calender or a soft calender as necessary. You may implement.

The transfer paper substrate has a Beck smoothness (JIS P8119) of preferably 50 seconds to 2,000 seconds, and more preferably 100 seconds to 2,000 seconds.
The Beck-type smoothness is measured by using a Beck-type smoothness tester to pass a certain amount of air through the space between the evaluation sample surface and the optical flat-finished glass standard surface and in a hermetically evacuated measuring instrument. This is a measurement of the time (seconds) required to enter. By using the transfer paper base material that has been smoothed as described above, the transfer paper 20 with the overcoat layer 17 having the pattern forming layer 16 shown in FIG.

-Pattern forming layer liquid (pattern forming layer ink)-
The pattern forming layer solution contains metal fine particles whose surface is coated with a dispersion stabilizer, a polymer component, and a compound capable of trapping the dispersion stabilizer, and contains a solvent and, if necessary, other components. It becomes.

--Metal fine particles--
As the metal component of the metal fine particles, one kind of metal selected from gold, silver, copper, platinum, palladium, tungsten, nickel, tantalum, bismuth, lead, indium, tin, zinc, titanium, and aluminum, or 2 Examples include alloys made of more than one kind of metal. Among these, for the purpose of forming a pattern such as an electrode, it is preferable to use a metal having excellent electrical conductivity such as gold, silver, copper, or platinum.
In addition, an oxide such as In ₂ O ₃ , SnO ₂ , ZnO, CdO, TiO ₂ , CdIn ₂ O ₄ , Cd ₂ SnO ₂ , Zn ₂ SnO ₄ , In ₂ O ₃ —ZnO, or an impurity compatible therewith is used. A dopant material; spinel compounds such as MgInO and CaGaO can also be used depending on the purpose.
The method for producing the metal fine particles is described in, for example, Chapter 3, “Inkjet Fine Wiring of Metal Nanoparticle Paste” (supervised by Katsuaki Suganuma) published by CM Publishing Co., Ltd. in March 2006. Various production methods have been reported in “Paste Properties”, and they can be synthesized by these methods.

-Dispersion stabilizer-
The surface of the metal fine particles is coated (protected) with a dispersion stabilizer.
The dispersion stabilizer protects the metal fine particles in a stable state by forming a coordinate bond with the metal element that is a metal component of the metal fine particles. A group having a lone electron pair such as nitrogen, oxygen and sulfur atoms is used. For example, a group containing a nitrogen atom includes an amino group. Examples of the group containing a sulfur atom include a sulfanyl group and a sulfide-type sulfanediyl group. Examples of the group containing an oxygen atom include a hydroxy group and an ether type oxy group.
Examples of the dispersion stabilizer having an amino group include alkylamine. As the alkylamine, the alkyl group preferably has 4 to 20 carbon atoms, more preferably 8 to 18 carbon atoms, and an alkyl group having an amino group at the terminal of the alkyl chain is used. In general, in forming a coordination bond, a primary amine type compound is preferable because it shows a higher binding ability, but secondary amine type and tertiary amine type compounds can also be used. Moreover, the compound in which two or more adjacent amino groups participate in a coupling | bonding, such as a 1, 2- diamine type compound and a 1, 3- diamine type compound, can also be utilized.
Examples of the dispersion stabilizer having a sulfanyl group include alkanethiols. As the alkanethiol, the alkyl group preferably has 4 to 20 carbon atoms, more preferably 8 to 18 carbon atoms, and an alkyl group having a sulfanyl group at the terminal of the alkyl chain is used. In general, primary thiol type compounds are preferred because they exhibit higher binding ability, but secondary thiol type and tertiary thiol type compounds can also be used. In addition, those in which two or more sulfanyl groups such as 1,2-dithiol type are involved in the binding can also be used.
Examples of the compound having a hydroxy group include alkanediol.

  In general, it is known that ultrafine metal particles having an average particle diameter of several nanometers to several tens of nanometers are sintered at a temperature much lower than their melting point. The reason why the melting point is lowered when the metal particle diameter is reduced to about nano-size is that the ratio of the active state atoms present on the surface of the metal particle to the whole of the high active state is increased, and the particle is diffused due to the surface diffusion of the metal atom. This is because the activation energy such as heat required for stretching the interface between each other becomes low.

When the metal fine particles are used for forming a pattern that requires conductivity such as an electrode, the particle diameter of the metal fine particles is preferably large enough to produce the melting point lowering effect described above. In order to disperse the metal fine particles in a nano-size colloidal form, for example, it is necessary to protect the metal component with a dispersion stabilizer. However, if the molecular layer covering the surface of the metal fine particles remains as it is, the fusion of the contact interface at a low temperature between the metal fine particles, which is indispensable for achieving excellent conductivity, is hindered. In addition, when the metal fine particles are used for pattern formation that requires conductivity, such as electrodes, the metal component involved in the conductivity after sintering needs to be in close contact with a substrate or an overcoat layer that becomes an insulating layer described later. For example, a polymer component is required as an adhesion component.
As the polymer component, a thermosetting resin is mainly used, and the resin is cured during sintering and contributes to adhesion. Similar to the dispersion stabilizer on the surface of the metal fine particles, the resin component contributing to the adhesion is also a factor that hinders the fusion of the contact interface at a low temperature between the metal fine particles and hinders the excellent conductivity of the metal component. Become.

  Thus, the dispersion stabilizer and polymer component of the metal fine particles inhibit the conductivity of the metal component. Therefore, an attempt has been made to effectively remove the dispersion stabilizer that covers the surface of the metal ultrafine particles in the process of heat-curing the thermosetting resin that is a polymer component. For example, an acid anhydride is used as a compound capable of trapping the dispersion stabilizer, and the dispersion stabilizer coordinated to the metal component is captured at a temperature at which the polymer component is thermally cured. Although this method inhibits the conductivity of the metal component to some extent, the removed dispersion stabilizer and polymer component are interposed between the metal particles, and the phenomenon of conductivity inhibition has not been solved.

  The transfer paper of the present invention includes metal fine particles coated (protected) with a dispersion stabilizer and a polymer component, and the metal particle dispersion stabilizer acts as a dopant for the polymer component. It is characterized in that it adheres to an overcoat layer that becomes a substrate or an insulating layer without impairing the properties.

--Polymer component--
The polymer component is not particularly limited as long as it is a π-conjugated polymer, and can be appropriately selected according to the purpose. For example, substituted and unsubstituted conductive polyaniline, polyparaphenylene, polyparaphenylene vinylene, polythiophene , Polyfuran, polypyrrole, polyselenophene, polyisothianaphthene, polyphenylene sulfide, polyacetylene, polypyridylvinylene, polyazine, and the like. These may be used individually by 1 type and may use 2 or more types together.

--Compound capable of trapping dispersion stabilizer--
In order for the dispersion stabilizer of the metal fine particles to act as a polymer dopant, it is effective to add a compound capable of capturing the dispersion stabilizer.
Examples of the compound capable of capturing the dispersion stabilizer include organic acids, acid anhydrides or derivatives thereof.
Examples of the organic acid include linear or branched saturated carboxylic acids having 1 to 10 carbon atoms such as formic acid, acetic acid, propionic acid, butanoic acid, hexanoic acid, and octylic acid; acrylic acid, methacrylic acid, crotonic acid, and cinnamic Examples thereof include unsaturated carboxylic acids such as acid, benzoic acid and sorbic acid; organic acids such as oxalic acid, malonic acid, sebacic acid, maleic acid, fumaric acid and itaconic acid.
Examples of the acid anhydride or derivative thereof include phthalic anhydride, trimellitic anhydride, pyromellitic anhydride, benzophenone tetracarboxylic anhydride, ethylene glycol bis (anhydro trimellitate), glycerol tris (anhydro trimellitate). Aromatic acid anhydrides such as maleic anhydride, succinic anhydride, tetrahydrophthalic anhydride, methyltetrahydrophthalic anhydride, methyl nadic anhydride, alkenyl succinic anhydride, hexahydrophthalic anhydride, methylhexahydrophthalic anhydride, etc. Cyclic aliphatic acid anhydrides; aliphatic acid anhydrides such as polyadipic acid anhydride, and the like. Among these, methyltetrahydrophthalic anhydride, methylhexahydrophthalic anhydride, or derivatives thereof are particularly preferable.

--Solvent--
As the solvent for dispersing the metal fine particles whose surface is coated with the dispersion stabilizer, the polymer component, and the compound capable of capturing the metal fine particle dispersion stabilizer, the wettability of the surface layer of the transfer paper base material or the outermost layer is used. An organic solvent is preferable in consideration of the solubility of the coated aqueous rewet paste layer.
As the organic solvent, saturated hydrocarbons, nonpolar or low polarity solvents are preferably used. The saturated hydrocarbon is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include heptane, octane, nonane, decane, undecane, dodecane, tridecane, tetradecane, pentadecane, and hexadecane. Among these, decane, undecane, dodecane, tridecane, and tetradecane are particularly preferable.
Examples of the nonpolar or low polarity solvent include xylene, toluene, ethylbenzene, mesitylene, hexane, heptane, octane, decane, dodecane, tetradecane, and cyclohexanecyclooctane.

The pattern forming layer liquid (pattern forming layer ink liquid) is appropriately prepared in consideration of the wettability between the surface of the transfer paper substrate and the ink droplets in order to form a pattern by an ink jet method. The wettability is controlled by appropriately adjusting the surface tension and viscosity (viscosity) of the ink liquid. In the case of the ink liquid used in the present invention, the surface tension and viscosity are appropriately adjusted by the type of solvent, the inclusions, and the surface tension adjusting agent.
In general, ink having a high surface tension has a stable ink droplet shape at the time of flight, but has poor wettability with a member used in a recording apparatus, and makes it difficult to supply ink. In order to eliminate such problems, it is preferable to add a surface tension adjusting agent.
Examples of the surface tension adjusting agent include acrylic surface tension adjusting agents, silicone surface tension adjusting agents, vinyl surface tension adjusting agents, fluorine surface tension adjusting agents, alcohols that can also be used as solvents, glycols, and the like. Is mentioned.
Examples of alcohols having a surface tension of 40 mN / m or less and a viscosity at 25 ° C. of 100 mPa · s or less include 1-butanol, 1-pentanol, 4-methyl-2-pentanol, 2-ethoxyethanol, 2-n-butoxyethanol, n-butyl carbitol, etc. are mentioned. Among these, 2-n-butoxyethanol and 1-butanol are particularly preferable from the viewpoint of maintaining long-term quality stability as an ink liquid.

The viscosity of the ink liquid is preferably 3 mPa · s to 40 mPa · s at 25 ° C., more preferably 5 mPa · s to 30 mPa · s, and still more preferably 7 mPa · s to 15 mPa · s. The ink liquid in the viscosity range has excellent high frequency characteristics and is suitable for high-speed printing.
When the viscosity is less than 3 mPa · s, the shape and frequency characteristics of ink droplets are likely to be poor.
The surface tension of the ink is preferably 15 mN / m to 50 mN / m, and more preferably 20 mN / m to 30 mN / m at 25 ° C.
As an ink jet type apparatus, various modes such as an on-demand type ink jet type using a piezoelectric element, a line type, and a serial type can be used.

<Heating process>
The heating step is a step of heating the transfer paper substrate on which the pattern forming layer is formed.
The heating temperature in heating after pattern formation is preferably 150 ° C. or higher, and more preferably 300 ° C. or higher. The heating temperature is preferably 400 ° C. or lower in consideration of deterioration of the transfer paper.
The heating time is preferably 10 minutes or more, and more preferably 30 minutes to 60 minutes.
Here, the concept of the mechanism of the present invention by heat treatment is as shown in FIG.
Since the dispersion stabilizer removed from the metal fine particles by heating acts as a dopant of the polymer component, even if the polymer component or the dispersion stabilizer is interposed between the metal fine particles, the conductivity of the portion is maintained, and the pattern forming layer The conductivity is not impaired.

<Overcoat layer forming step>
The overcoat layer forming step is a step of forming an overcoat layer on the pattern forming layer.

The overcoat layer is not particularly limited when it is intended to be simply transferred, and can be appropriately selected according to the purpose, but when the overcoat layer is used as a functional thin film. For example, epoxy resin, phenol resin, unsaturated polyester resin, vinyl ester resin, diallyl phthalate resin, oligoester acrylate resin, xylene resin, bismaleimide triazine resin, furan resin, urea resin, polyurethane resin, melamine resin, silicone resin, etc. Thermosetting resins are preferred. Among these, PAI (polyamideimide), PEI (polyetherimide), PES (polyethersulfone), and PVPh (polyvinylphenol) have high insulation and heat resistance, and can be dissolved in a solvent. Preferred as an organic insulating layer. For example, polyimides that are soluble in NMP, polyamide-imide resins such as Viromax (registered trademark) (manufactured by Toyobo Co., Ltd.), HR-11NN, HR-13NX, HR-14ET, HR-15ET, HR-16NN, etc. Is mentioned.
By using such an organic insulating layer, the overcoat layer 7 can be provided with insulating properties.

In addition, as shown in FIG. 2, good insulation can be obtained by applying the inorganic insulating layer 18 before the overcoat layer 17 is formed. In addition, after forming the pattern formation layer 16, the transfer base material can be cut into an appropriate size, the inorganic insulating layer 18 can be formed using a sputtering method, and then the overcoat layer 17 can be formed.
Examples of the inorganic insulating layer 18 include silicon nitride oxide by a vapor deposition method, a sputtering method, a PVD method (Physical Vapor Deposition), a low pressure CVD method (LPCVD method), or a CVD method (Chemical Vapor Deposition) such as a plasma CVD method. It is also possible to form an insulating layer using an inorganic insulating material such as a film (SiON). Among these, the sputtering method is particularly preferable because the inorganic insulating layer 18 can be formed without damaging the production of the transfer paper.

  The transfer paper overcoat layer 17 (see FIG. 2) of the present invention is used, for example, when a transfer paper base material is continuously supplied from roll paper, for example, blade coater, air knife coater, roll coater, brush coater, curtain coater. When using as a cut paper using a coating apparatus such as a Champec coater or a bar coater, it is coated using a spin coater and dried to form an overcoat layer.

(Transfer paper)
The transfer paper of the present invention is manufactured by the transfer paper manufacturing method of the present invention.
The transfer paper has a Beck smoothness (JIS P8119) of preferably 1,000 seconds or more, and more preferably 1,100 seconds or more. If the Beck smoothness is less than 1,000 seconds, interlayer separation may occur when the transfer layer is laminated.
The transfer sheet is for transferring a laminated film including a pattern forming layer and an overcoat layer onto a transfer target, and the transfer target is preferably a flexible film subjected to a gas barrier property treatment.

-Transferee-
As the flexible film to be transferred, various film forms such as PEN (polyethylene naphthalate), PET (polyethylene terephthalate), PES (polyether sulfone), and PC (polycarbonate) can be used.
When the transistor is required to have characteristics such as flexibility, bendability, elasticity, and durability, a flexible film is preferable as the substrate, and a flexible film imparted with gas barrier properties is particularly preferable.
There is no restriction | limiting in particular as a manufacturing method of the flexible film which provided the said gas barrier property, According to the objective, it can select suitably, For example, (1) knead | mixing an inorganic planar material to the said flexible film resin, etc. A method of kneading, (2) a method of mixing a montmorillonite or the like as an inorganic planar material with an insulating resin solution that can be dissolved in a solvent used for an overcoat layer, and applying and drying to form a flexible film having gas barrier properties; 3) A method of directly applying an inorganic planar material to an insulating resin solution that can be dissolved in a solvent used for an overcoat layer on a flexible film having no gas barrier property. Among these, the method of imparting gas barrier properties by directly applying (3) is particularly preferable because it can be applied to any flexible film and can be applied to both sides thereof.

Here, the transfer paper shown in FIG. 2 has a pattern forming layer 16 and an overcoat layer 17 as the outermost layer on the transfer paper base material 10 shown in FIG. 1, and an inorganic insulating layer 18 as necessary. Do it.
A pattern forming layer 16 is formed on the transfer paper substrate shown in FIG. 1 by an ink jet method, an inorganic insulating layer 18 is formed if necessary, and an overcoat layer 17 is formed thereon, as shown in FIG. The transfer paper 20 is the present invention.
When the transfer paper 20 is immersed in water, the paste dissolves, and the inorganic insulating layer 18 and the pattern forming layer 16 that are protected by the overcoat layer 17 and formed as necessary are separated from the first coat layer 13. By sticking this on a flexible film transfer object, a laminated film including an overcoat layer and a pattern forming layer can be transferred. A flexible film having functionality can be obtained by repeating this transfer step a plurality of times.

  When the transfer paper of the present invention is used as a cut paper, the back coat layer 11 made of ethylene glycol or the like may be formed on the back surface of the base paper 12 in order to prevent curling. A functional thin film such as an organic thin film transistor can be produced by sequentially transferring to the flexible film transfer body in a state where the smoothness of the outermost layer is high.

Here, FIG. 4 is a schematic diagram of a manufacturing flow when continuously producing the transfer paper of the present invention.
First, a transfer paper base material is supplied in a roll shape, a conductive pattern is formed by an inkjet printer in zone A, and an overcoat layer is applied in zone B through first drying. After passing through the second drying, it is cut into a desired size in zone C and transferred to a flexible film in zone D. The roll-shaped transfer paper base material supply and zones A to D are linked to an operation panel (not shown) and are controlled by a personal computer. In the zone C, the transfer paper of the present invention can be rolled up and collected and shipped. Similarly, a transfer sheet having a different pattern forming layer, a transfer sheet having a semiconductor, or the like may be collected in a roll shape, and the transfer process of zone D may be performed separately. In addition, when the transfer paper of the present invention is prepared using a cut paper (not shown) as a transfer substrate, it is obtained by applying a constant pressure load with a highly smooth film when drying the insulating film as a smoothness imparting method. The reliability of imparting smoothness to the transfer paper is improved.

-Use-
The transfer paper of the present invention is used for production of various functional thin films, for example, rigid and flexible printed boards, organic thin film transistors (TFTs), IC chips, LSI circuits, electronic paper, transparent electrodes for displays, light control devices, solar It is suitably used for batteries, touch panels and the like.

(Method for producing functional thin film)
The method for producing a functional thin film of the present invention includes at least a transfer step, a circuit pattern forming layer formation step, and further includes other steps as necessary.

<Transfer process>
In the transfer step, a laminated film including a pattern forming layer and an overcoat layer on the transfer paper is formed by applying water to the transfer paper of the present invention to dissolve the glue layer and bringing it into contact with the transfer paper. It is the process of transferring to the flexible film which performed the gas barrier process.
It is preferable that the transfer step is repeated a plurality of times to be laminated on the laminated film.
Here, “multiple layers” means that a transfer sheet having a pattern forming layer is prepared and sequentially transferred onto a flexible film as a transfer target and laminated, thereby producing a functional thin film such as an organic thin film transistor. It becomes possible.

-Circuit pattern formation layer formation process-
The circuit pattern forming layer forming step is a step of forming a circuit pattern forming layer on the laminated film.

  According to the method for producing a functional thin film of the present invention, a functional thin film such as an organic thin film transistor can be efficiently produced even on a flexible film.

EXAMPLES Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited thereto.
In the following examples, the smoothness, viscosity, surface tension, and specific resistance are values measured as follows.

<Smoothness>
The smoothness of the transfer paper was measured using a Digibeck smoothness tester (manufactured by Toyo Seiki Seisakusho Co., Ltd.).

<Viscosity>
The viscosity at 25 ° C. was measured with a VISCOMATE VM-150III type (manufactured by Toki Sangyo Co., Ltd.).

<Surface tension>
The surface tension at 25 ° C. was measured with a Kyowa Interface Science CBVP-Z type (manufactured by Kyowa Interface Science Co., Ltd.).

<Specific resistance value>
The specific resistance value of the pattern formation layer was measured with a Mitsubishi MC-T400, 4 deep needle probe (manufactured by Dia Instruments).

(Production Example 1)
-Production of transfer paper substrate 1-
Hardwood (L-BKP 100%) was made using a Yankee paper machine to produce a base paper. After applying a light calcium carbonate dispersion to this base paper, a carboxycellulose: polyvinyl alcohol = 1: 1 (mass ratio) mixed solution was applied as a slow water re-wetting paste and dried. Next, yellow dextrin and an ethylene-vinyl acetate copolymer mixed solution were applied as a rapid aqueous rewetting paste, and a surface treatment was performed with a super calender to prepare a transfer paper substrate 1. The transfer paper base material 1 had a Beck smoothness of 800 seconds.

(Production Example 2)
-Production of transfer paper base material 2-
A PET film (smoothness of 3,000 seconds or more) is used in place of the base paper of the transfer paper base material 1 and the slow water re-wetting paste and the fast water re-wetting paste used in the transfer paper base material 1 are applied and super Surface treatment was performed with a calender to prepare a transfer paper substrate 2. The transfer paper substrate 2 had a Beck smoothness of 3,000 seconds.

(Production Example 3)
-Preparation of ink liquid 1 for conductive pattern forming layer-
Silver particle dispersion manufactured by Vacuum Metallurgical Co., Ltd. (Ag1T: Silver fine particle liquid having an average particle diameter of 5 nm using dodecylamine as a dispersion stabilizer in a toluene solvent / solid content concentration of 7% by mass of dodecylamine and 35% of silver component %) Was concentrated under reduced pressure and then redispersed in tetradecane. The solid content concentration of this liquid was 42% by mass.
Further, 3% by mass of methylhexahydrophthalic anhydride and 6% by mass of polyaniline (CAS number: 25233-30-1) were added as acid anhydrides to prepare a conductive pattern forming layer ink liquid 1. This ink liquid 1 had a viscosity at 25 ° C. of 24 mPa · s and a surface tension of 33 N / m.

(Production Example 4)
-Preparation of ink liquid 2 for conductive pattern forming layer-
To 500 ml of silver perchlorate ethanol solution (10 mM), add 15 g of bis (1,1-trimethylammoniumdecanoylaminoethyl) disulfide, and slowly drop 300 ml of sodium borohydride solution (0.8 M) with vigorous stirring. Ions were reduced to obtain a dispersion of silver particles coated with quaternary ammonium. The dispersion was concentrated and diluted with tetradecane to prepare a conductive pattern forming layer ink liquid 2 having a solid content concentration of 67% by mass.
This ink liquid 2 had a viscosity at 25 ° C. of 16 mPa · s and a surface tension of 28 N / m. When the size of the silver particles was measured with an electron microscope, the average particle size was 350 nm.

(Production Example 5)
-Preparation of ink liquid 3 for conductive pattern forming layer-
A conductive pattern forming layer ink liquid 3 was produced in the same manner as in Production Example 3 except that methylhexahydrophthalic anhydride was not added as an acid anhydride in Production Example 3. This ink liquid 3 had a viscosity at 25 ° C. of 19 mPa · s and a surface tension of 30 N / m.

(Production Example 6)
-Production of overcoat layer liquid 1-
Polyvinylphenol resin was dissolved in propylene glycol monomethyl ether so that the solid content was 11.5% by mass. This was designated as overcoat layer solution 1.

(Production Example 7)
-Preparation of overcoat layer liquid 2-
A thermosetting resin solution (brand: MIG-N, manufactured by Jujo Chemical Co., Ltd.) was diluted to 20% by mass with a Tetron solvent. This was designated as overcoat layer liquid 2.

Example 1
A conductive pattern forming layer ink liquid 1 is loaded into an ink jet apparatus (Ricoh Co., Ltd., Ypsio GX3000), and a linear pattern having a length of 10 cm is placed at a pitch of 63 μm on a 10 cm portion from the center of the transfer paper substrate 1. A pattern forming layer was formed.
Next, after drying at 200 ° C. for 30 minutes (first drying), one of the pattern forming layers was arbitrarily selected and the specific resistance value was measured. As a result, a good value of 4.1 × 10 ⁻⁶ Ω · cm was obtained. Indicated.
Next, after measuring the specific resistance value, the overcoat layer solution 1 was coated with a spin coater. It was dried at 100 ° C. for 30 minutes (second drying), a 12 cm ² square including the linear pattern portion of the transfer paper was cut out, and its Beck smoothness was measured and found to be 1,800 seconds.
Water was applied to the produced transfer paper and transferred to a polyethylene terephthalate (PET) film as a transfer target. As a result, a good transfer product could be obtained.
<Adhesion evaluation>
Next, an adhesive tape is applied to both surfaces of the obtained transfer material, and the adhesive tape is peeled off at the same time, thereby performing an adhesion test between the transfer material comprising the pattern forming layer and the overcoat layer and the PET film as the transfer object. went. As a result, the adhesion was good.

(Comparative Example 1)
In Example 1, a pattern forming layer was formed in the same manner as in Example 1 except that the conductive pattern forming layer ink liquid 3 was used instead of the conductive pattern forming layer ink liquid 1.
Subsequently, after drying at 200 ° C. for 30 minutes (first drying), one of the pattern forming layers was arbitrarily selected and the specific resistance value was measured. As a result, a high value of 2.4 Ω · cm was shown.
Next, when the overcoat layer liquid 1 was coated with a spin coater in the same manner as in Example 1, a problem that the pattern forming layer floated occurred, and the overcoat layer could not be formed.

(Comparative Example 2)
A pattern forming layer was formed in the same manner as in Example 1 except that the conductive pattern forming layer ink liquid 1 was replaced with the conductive pattern forming layer ink liquid 2 in Example 1.
Next, after drying at 200 ° C. for 30 minutes (first drying), one of the pattern forming layers was arbitrarily selected and the specific resistance value was measured. As a result, a high value of 1.8 Ω · cm was shown.
Next, when the overcoat layer solution 1 was coated with a spin coater in the same manner as in Example 1, the smoothness of this transfer paper was 880 seconds.
Next, as a result of performing an adhesion test similar to that of Example 1, the adhesion was good, but it could not be expected to be used as a functional film such as a transistor because the specific resistance of the pattern forming layer was high.

(Example 2)
A pattern forming layer was formed in the same manner as in Example 1.
Next, after drying at 400 ° C. for 1 hour (first drying), one of the pattern forming layers was arbitrarily selected and the specific resistance value was measured. As a result, a good value of 3.8 × 10 ⁻⁶ Ω · cm was obtained. Indicated.
Next, as a result of performing transfer in the same manner as in Example 1, a satisfactory transfer product could be obtained. The transfer paper obtained had a Beck smoothness of 1,400 seconds. Moreover, the result of the adhesion test performed in the same manner as in Example 1 was also good.

(Example 3)
In the same manner as in Example 1, a linear pattern having a length of 10 cm was formed at a pitch of 63 μm in a 10 cm portion from the center of the transfer paper base material 1 to the left and right.
Subsequently, it was dried at 300 ° C. for 30 minutes (first drying). Thereafter, 12 cm ² including the linear pattern portion of the transfer paper is cut out to form a ZnS—SiO ₂ layer by sputtering, and then the overcoat layer liquid 2 is used to produce a transfer paper in the same manner as in Example 1. did. The transfer paper obtained had a Beck smoothness of 2,300 seconds.
Next, as a result of applying water to the obtained transfer paper and transferring it to a PET film, the transfer paper was successfully transferred. Moreover, the result of the adhesion test performed in the same manner as in Example 1 was also good.

(Comparative Example 3)
In Example 1, an overcoat layer was formed in the same manner as in Example 1 except that the transfer paper base 2 was used instead of the transfer paper base 1.
The specific resistance value of the pattern forming layer was as good as 4.1 × 10 ⁻⁶ Ω, and the Beck smoothness was also good as 3,300 seconds.
Next, water was applied to the obtained transfer paper, and even if it was transferred to a PET film in the same manner as in Example 1, it could not be separated, so transfer could not be performed.

Example 4
When the transfer paper obtained in Example 1 was transferred onto the PET film transfer obtained in the same manner as in Example 1 by the same method as in Example 1, it could be transferred well, and PET A film laminate was obtained.
About the obtained PET film laminated body, the result of the adhesive test which affixed an adhesive tape on both surfaces of the PET film side and the outermost layer of a laminated body, and peeled an adhesive tape simultaneously was favorable.

(Example 5)
When the transfer paper obtained in Example 1 was transferred onto the PET film laminate obtained in Example 4 by the same method as in Example 4, it was possible to transfer it satisfactorily. About the obtained PET film laminated body, the result of the adhesiveness test done like Example 4 was favorable.

(Example 6)
-Adhesion test-
The transfer surface of the transfer paper having a Beck smoothness of 1,800 seconds prepared in Example 1 was adjusted with a sand blaster. 1 to 8 Beck type smoothness transfer paper was prepared.
Next, according to the same method as in Examples 4 and 5, first, No. 1 was applied to the PET film. Transfer papers having different smoothness of 1 to 8 were transferred, and then the transfer paper used in Example 1 was transferred.
Using the obtained PET film transfer product, an adhesion test was conducted in the same manner as in Example 1 and evaluated according to the following criteria. The results are shown in Table 1.
〔Evaluation criteria〕
×: The transfer layer adheres to the adhesive tape ○: The transfer layer does not adhere to the adhesive tape

(Example 7)
-Durability test-
In the same manner as in Example 6, transfer paper (Nos. 1 to 8 in Table 1) having different smoothness is transferred to a PET film, and then the transfer paper used in Example 1 is transferred to transfer a PET film. Was made.
Next, the obtained PET film was transferred to a bendable durability tester capable of giving the film expansion and contraction by driving the left and right rubber fixing jigs 4 cm inward at a cycle of 60 times per minute. Both ends of the object were fixed with a fixing jig with rubber, and an endurance test was conducted for 1 hour to evaluate the presence or absence of abnormality such as breakage or peeling. The results are shown in Table 1.

From the result of Table 1, No. whose Beck type smoothness is 1,000 seconds or more. 5-8 were found to have excellent adhesion and durability.

  The transfer paper manufactured by the transfer paper manufacturing method of the present invention can be applied to various functional thin films. For example, rigid and flexible printed boards, organic thin film transistors (TFTs), IC chips, LSI circuits, electronic paper, displays It is suitably used for transparent electrodes, light control devices, solar cells, touch panels and the like.

DESCRIPTION OF SYMBOLS 1 Roll-shaped transfer paper base material 2 Transfer paper base material 3 Inkjet printer 4 Conductive pattern 5 Overcoat layer liquid 6 Smooth roller 7 Cutting machine 8 Water bath 10 Transfer paper base material 11 Backcoat layer 12 Base paper 13 First coat layer 14 Second coating layer 15 Third coating layer 16 Pattern forming layer 17 Overcoat layer 18 Inorganic insulating layer 20 Transfer paper

Japanese Patent Laid-Open No. 2003-234561 Japanese Patent Laid-Open No. 2004-111818

Claims (13)

Capable of capturing fine metal particles, polymer components, and dispersion stabilizers coated with a dispersion stabilizer on a transfer paper base material that includes a slow water-repellent paste layer and a fast water-soluble wet paste layer on the base paper surface A pattern forming layer forming step of forming a pattern forming layer by applying a liquid for a pattern forming layer containing an appropriate compound;
A heating step of heating the transfer paper substrate on which the pattern forming layer is formed;
An overcoat layer forming step of forming an overcoat layer on the pattern forming layer.   The method for producing a transfer paper according to claim 1, wherein the metal fine particles are at least one selected from gold, nickel, copper, platinum, palladium, silver, and alloys thereof.   The dispersion stabilizer is a compound having a group capable of coordinating with a metal element, and the group capable of coordinating with the metal element includes a group containing a nitrogen atom, a group containing an oxygen atom, and a group containing a sulfur atom. The transfer paper manufacturing method according to claim 1, wherein the transfer paper is any one of the methods.   4. The method for producing a transfer paper according to claim 1, wherein the dispersion stabilizer is desorbed from the metal fine particles by heating to become a dopant of a polymer component.   The method for producing a transfer paper according to claim 1, wherein the polymer component is a π-conjugated polymer compound.   The method for producing a transfer paper according to any one of claims 1 to 5, wherein the compound capable of capturing the dispersion stabilizer is either an acid anhydride or a derivative thereof.   The method for producing a transfer sheet according to claim 1, wherein the pattern forming layer is formed by an ink jet method.   A transfer sheet manufactured by the transfer sheet manufacturing method according to claim 1.   The transfer paper according to claim 8, wherein the transfer paper has a Beck smoothness of 1,000 seconds or more. Transfer paper for transferring a laminated film including a pattern forming layer and an overcoat layer to a transfer target,
The transfer sheet according to claim 8, wherein the transfer target is a flexible film that has been subjected to a gas barrier treatment.   A laminate including a pattern forming layer and an overcoat layer on the transfer paper by applying water to the transfer paper according to any one of claims 8 to 10 to dissolve the glue layer and bringing it into contact with the transfer paper. The manufacturing method of a functional thin film characterized by including the transfer process which transfers a film | membrane to the flexible film which performed the gas barrier process at least.   The method for producing a functional thin film according to claim 11, comprising a circuit pattern forming layer forming step of forming a circuit pattern forming layer on the laminated film.   The method for producing a functional thin film according to any one of claims 11 to 12, wherein the transfer step is repeated a plurality of times to be laminated on the laminated film.