阅读说明：本技术 感光性纤维形成用组合物及纤维图案的形成方法 (Composition for forming photosensitive fiber and method for forming fiber pattern ) 是由 横山义之 岸冈高广 于 2020-01-16 设计创作，主要内容包括：本发明的课题是提供将表面具有金属层的基材使用具有特定的组成的感光性纤维进行了加工的金属图案的制造方法、金属图案的制造方法、用于制造该感光性纤维的组合物,优选提供便宜且柔软的透明配线图案。解决手段是本发明的感光性纤维为包含正型感光性材料的感光性纤维。正型感光性材料可以包含酚醛清漆树脂等。本发明的金属图案的制造方法包含下述工序：在表面具有金属层的基材上形成由感光性纤维构成的纤维层的第1工序；将该纤维层经由掩模进行曝光的第2工序；将该纤维层通过显影液进行显影,形成感光性纤维图案的第3工序；以及将该金属层利用蚀刻液进行蚀刻,进一步将感光性纤维除去,从而形成网眼状金属图案的第4工序。(The invention provides a method for manufacturing a metal pattern by processing a substrate having a metal layer on the surface thereof with a photosensitive fiber having a specific composition, a method for manufacturing a metal pattern, and a composition for manufacturing the photosensitive fiber, and preferably provides an inexpensive and flexible transparent wiring pattern. The photosensitive fiber of the present invention is a photosensitive fiber containing a positive photosensitive material. The positive photosensitive material may include a novolac resin or the like. The method for manufacturing a metal pattern of the present invention includes the steps of: a step 1 of forming a fiber layer made of a photosensitive fiber on a substrate having a metal layer on the surface thereof; a 2 nd step of exposing the fiber layer through a mask; a 3 rd step of forming a photosensitive fiber pattern by developing the fiber layer with a developer; and a 4 th step of etching the metal layer with an etching solution to further remove the photosensitive fiber, thereby forming a mesh-like metal pattern.)

1. A photosensitive fiber is composed of a positive photosensitive material, wherein the positive photosensitive material contains a (meth) acrylic resin or a polyvinyl phenol resin, and a dissolution inhibitor.

2. A composition for producing a photosensitive fiber, which comprises a (meth) acrylic resin or a polyvinyl phenol resin, a dissolution inhibitor, and a solvent.

3. The composition of claim 2, further comprising an electrolyte.

4. A method for producing a photosensitive fiber, comprising a step of spinning the composition according to claim 2 or 3.

5. A method for producing a photosensitive fiber pattern, comprising the following steps 1,2 and 3,

step 1: spinning the composition of claim 2 or 3 on a substrate to form a fiber layer comprising photosensitive fibers;

and a 2 nd step: exposing the fiber layer through a mask;

and a 3 rd step: the fiber layer is developed with a developer to form a photosensitive fiber pattern.

6. A method for manufacturing a metal pattern, comprising the following steps 1 to 4,

step 1: forming a fiber layer composed of photosensitive fibers on a substrate having a metal layer on a surface thereof;

and a 2 nd step: exposing the fiber layer through a mask;

and a 3 rd step: developing the fiber layer with a developer to form a photosensitive fiber pattern;

and a 4 th step: the metal layer is etched with an etching solution to remove the photosensitive fibers, thereby forming a mesh-like metal pattern.

7. The method for producing a metal pattern according to claim 6, wherein the photosensitive fiber comprises the following (i), the following (ii), the following (iii), or the following (iv),

(i) a novolac resin and a dissolution inhibitor, wherein,

(ii) a polyvinyl phenol resin or a (meth) acrylic resin, and a photoacid generator,

(iii) a polyvinyl phenol resin or a (meth) acrylic resin containing a structural unit having a photoacid generating group in a side chain,

(iv) a polyvinyl phenol resin or a (meth) acrylic resin, and a dissolution inhibitor.

8. The method for producing a metal pattern according to claim 6 or 7, wherein the mesh-like metal pattern has a light transmittance of 5% or more in a wavelength region of visible light.

9. The method for producing a metal pattern according to any one of claims 6 to 8, wherein the metal pattern is a metal pattern having a number of bending times of 10 or more, which can maintain conductivity in a repeated bending test.

10. A method for producing a base material with a metal pattern, comprising the following steps 1 to 4,

step 1: forming a fiber layer composed of photosensitive fibers on a substrate having a metal layer on a surface thereof;

and a 2 nd step: exposing the fiber layer through a mask;

and a 3 rd step: developing the fiber layer with a developer to form a photosensitive fiber pattern;

and a 4 th step: the metal layer is etched with an etching solution to remove the photosensitive fibers, thereby forming a mesh-like metal pattern.

11. The method for producing a substrate with a metal pattern according to claim 10, wherein the photosensitive fiber comprises the following (i), or comprises the following (ii), or comprises the following (iii), or comprises the following (iv),

(i) a novolac resin and a dissolution inhibitor, wherein,

(ii) a polyvinyl phenol resin or a (meth) acrylic resin, and a photoacid generator,

(iii) a polyvinyl phenol resin or a (meth) acrylic resin containing a structural unit having a photoacid generating group in a side chain,

(iv) a polyvinyl phenol resin or a (meth) acrylic resin, and a dissolution inhibitor.

12. A metal-patterned substrate produced by the method for producing a metal-patterned substrate according to claim 10 or 11.

13. The base material with a metal pattern according to claim 12, wherein the mesh-like metal pattern has a light transmittance of 5% or more in a wavelength region of visible light.

14. The metal-patterned substrate according to claim 12 or 13, which is capable of maintaining conductivity 10 or more times in repeated bending tests.

Technical Field

The present invention relates to a composition for forming photosensitive fibers and a method for forming a fiber pattern. For example, a substrate with a metal pattern can be obtained by coating a substrate having a metal layer on the surface thereof with a photosensitive fiber containing a photosensitive material and then etching the metal using the photosensitive fiber as a mask.

Background

In recent years, as the demand for solar cells and touch panels has increased, the market for transparent conductive films and transparent wiring patterns using ITO (Indium Tin Oxide) films has expanded. However, indium, which is a rare metal, is expensive, fragile, and also not very resistant to bending, and therefore development of alternative materials is strongly demanded.

Recently, the use of polymer nanofibers has been advanced in various areas such as clothing, batteries, and medical care due to the development of electrospinning (electric field spinning). Among them, newly studied: a method of forming a transparent conductive film having a metal network structure finer than the wavelength of visible light by etching a metal thin film using a fine mesh structure of a polymer nanofiber as an etching mask. (non-patent documents 1 and 2)

Patent documents 1 and 2 describe techniques (photosensitive nanofiber formation techniques) in which photosensitivity is imparted to polymer nanofibers obtained by an electrospinning method, and stacked nanofiber sheets are patterned into arbitrary shapes by using light.

Documents of the prior art

Patent document

Patent document 1: international publication No. 2015/056789 pamphlet

Patent document 2: international publication No. 2016/171233 pamphlet

Non-patent document

Non-patent document 1: keisuke Azuma, Koichi Sakajiri, Hidetoshi Matsumoto, Sungmin Kang, Junji Watanabe and Masatoshi Tokita, Mat.Lett., 115, 187(2014)

Non-patent document 2: tianda He, Aozhen Xie, Darrell H.Reneker and Yu Zhu, ACS Nano, 8(5), 4782(2014)

Disclosure of Invention

Problems to be solved by the invention

The invention provides a method for manufacturing a metal pattern, and a composition for manufacturing the photosensitive fiber, wherein the method for manufacturing the metal pattern uses a photosensitive fiber with a specific composition to process a substrate with a metal layer on the surface.

As an example of a specific example of the above problem, a photosensitive nanofiber is used for a transparent conductive film, thereby providing an inexpensive and flexible transparent wiring pattern and a film with a transparent wiring pattern in place of an ITO film.

Means for solving the problems

The inventors of the present invention found that: the present inventors have completed the present invention by forming a photosensitive polymer having a specific composition into nanofibers (fibers) and depositing the nanofibers on a metal thin film deposited on a film by an electrospinning method, irradiating the photosensitive fibers with light through a photomask to form a pattern into a wiring shape, and etching the metal thin film using the photosensitive fibers as an etching mask to form a wiring pattern having a fine mesh structure of a metal having both bending resistance and conductivity.

Namely, the present invention relates to the following aspects.

1. A photosensitive fiber is composed of a positive photosensitive material, wherein the positive photosensitive material contains a (meth) acrylic resin or a polyvinyl phenol resin, and a dissolution inhibitor.

2. A composition for producing a photosensitive fiber, which comprises a (meth) acrylic resin or a polyvinyl phenol resin, a dissolution inhibitor, and a solvent.

3. The composition of 2 above, further comprising an electrolyte.

4. A method for producing a photosensitive fiber, comprising a step of spinning the composition according to 2 or 3.

5. A method for manufacturing a photosensitive fiber pattern, comprising the following 1 st step, 2 nd step and 3 rd step, wherein the 1 st step: spinning the composition of 2 or 3 on a substrate to form a fiber layer composed of photosensitive fibers; and a 2 nd step: exposing the fiber layer through a mask; and a 3 rd step: the fiber layer is developed with a developer to form a photosensitive fiber pattern.

6. A method for manufacturing a metal pattern, comprising the following steps 1 to 4, wherein the step 1 comprises: forming a fiber layer composed of photosensitive fibers on a substrate having a metal layer on a surface thereof; and a 2 nd step: exposing the fiber layer through a mask; and a 3 rd step: developing the fiber layer with a developer to form a photosensitive fiber pattern; and a 4 th step: the metal layer is etched with an etching solution to remove the photosensitive fibers, thereby forming a mesh-like metal pattern.

7. The method for producing a metal pattern according to claim 6, wherein the photosensitive fiber comprises the following (i), or comprises the following (ii), or comprises the following (iii), or comprises the following (iv),

(i) a novolak resin and a dissolution inhibitor, (ii) a polyvinyl phenol resin or a (meth) acrylic resin, and a photoacid generator, (iii) a polyvinyl phenol resin or a (meth) acrylic resin containing a structural unit having a photoacid generating group in a side chain, (iv) a polyvinyl phenol resin or a (meth) acrylic resin, and a dissolution inhibitor.

8. The method for manufacturing a metal pattern according to the above 6 or 7, wherein the mesh-like metal pattern has a light transmittance of 5% or more in a wavelength region of visible light.

9. The method of manufacturing a metal pattern according to any one of the above 6 to 8, wherein the metal pattern is a metal pattern that can maintain conductivity in a repeated bending test with a number of bending times of 10 or more.

10. A method for manufacturing a base material with a metal pattern, comprising the following steps 1 to 4, wherein the step 1 comprises: forming a fiber layer composed of photosensitive fibers on a substrate having a metal layer on a surface thereof; and a 2 nd step: exposing the fiber layer through a mask; and a 3 rd step: developing the fiber layer by a developing solution to form a photosensitive fiber pattern; and a 4 th step: the metal layer is etched with an etching solution to remove the photosensitive fibers, thereby forming a mesh-like metal pattern.

11. The method for producing a substrate with a metal pattern according to the above 10, wherein the photosensitive fiber comprises the following (i), or comprises the following (ii), or comprises the following (iii), or comprises the following (iv),

(i) a novolak resin and a dissolution inhibitor, (ii) a polyvinyl phenol resin or a (meth) acrylic resin, and a photoacid generator, (iii) a polyvinyl phenol resin or a (meth) acrylic resin containing a structural unit having a photoacid generating group in a side chain, (iv) a polyvinyl phenol resin or a (meth) acrylic resin, and a dissolution inhibitor.

12. A metal-patterned substrate produced by the method for producing a metal-patterned substrate according to item 10 or item 11 above.

13. The metal-patterned substrate according to claim 12, wherein the mesh-like metal pattern has a light transmittance of 5% or more in a visible light wavelength region.

14. The metal-patterned substrate according to 12 or 13, wherein the number of times of bending that can maintain conductivity in a repeated bending test is 10 or more.

ADVANTAGEOUS EFFECTS OF INVENTION

According to the present invention, a photosensitive fiber capable of easily forming a complicated and fine resist pattern, a fiber pattern formed using the photosensitive fiber, and methods for producing the same can be provided.

Further, the present invention can provide a composition for producing the photosensitive fiber (photosensitive fiber-forming composition).

Further, according to the present invention, a metal pattern formed by the above fiber pattern, a base material having the metal pattern, and methods for producing the same can be provided.

Drawings

Fig. 1 is a schematic view of a method for forming a transparent wiring pattern using a photosensitive fiber.

Detailed Description

1. Photosensitive fiber and method for producing same

The fiber of the present invention is mainly characterized by containing a positive photosensitive material. That is, the fiber of the present invention is preferably a fiber obtained by spinning (more preferably, electrospinning) a raw material composition containing at least a positive photosensitive material.

In the present invention, a fiber containing a positive photosensitive material is sometimes referred to as a "positive photosensitive fiber".

The diameter of the fiber of the present invention may be appropriately adjusted depending on the use of the fiber, and is not particularly limited, but from the viewpoint of application to an etching mask, a medical material, a cosmetic material, and the like in processing various substrates used in a display and a semiconductor, the fiber of the present invention is preferably a fiber (nanofiber) having a diameter of nanometer order (for example, 1 to 1000nm) and/or a fiber (microfiber) having a diameter of micrometer order (for example, 1 to 1000 μm). In the present invention, the diameter of the fiber is measured by a Scanning Electron Microscope (SEM).

The "positive photosensitive material" in the present invention refers to a material that changes from being poorly alkali-soluble or insoluble to being readily alkali-soluble by the action of light (for example, a positive photoresist, a positive photosensitive resin composition, and the like).

The positive photosensitive material is not particularly limited as long as it can be in a fiber form, and any known material conventionally used as a positive photoresist, a positive photosensitive resin composition, or the like can be used. There may be mentioned, for example, (i) a novolak resin and a dissolution inhibitor; (ii) a polyvinyl phenol resin or a (meth) acrylic resin, and a photoacid generator; (iii) a polyvinyl phenol resin or a (meth) acrylic resin containing a structural unit having a photoacid generating group in a side chain; and the like.

Alternatively, (iv) the polyvinyl phenol resin, the (meth) acrylic resin, and the dissolution inhibitor are also positive photosensitive materials used as positive photosensitive resin compositions and the like.

The positive photosensitive material used in the present invention may contain the above-mentioned (i), or contain the above-mentioned (ii), or contain the above-mentioned (iii), or contain the above-mentioned (iv).

The novolak resin can be used without limitation as a material conventionally used for a positive photosensitive material, and examples thereof include resins obtained by polymerizing phenols and aldehydes in the presence of an acid catalyst.

Examples of the phenols include cresols such as phenol, o-cresol, m-cresol, and p-cresol; xylenols such as 2, 3-xylenol, 2, 4-xylenol, 2, 5-xylenol, 2, 6-xylenol, 3, 4-xylenol, and 3, 5-xylenol; alkylphenols such as o-ethylphenol, m-ethylphenol, p-ethylphenol, 2-isopropylphenol, 3-isopropylphenol, 4-isopropylphenol, o-butylphenol, m-butylphenol, p-butylphenol, and p-tert-butylphenol; trialkylphenols such as 2,3, 5-trimethylphenol and 3,4, 5-trimethylphenol; polyhydric phenols such as resorcinol, catechol, hydroquinone monomethyl ether, pyrogallol, phloroglucinol and the like; alkyl polyphenols such as alkylresorcinol, alkylcatechol, and alkylhydroquinone (any alkyl group has 1 to 4 carbon atoms); alpha-naphthol, beta-naphthol, hydroxybiphenyl, bisphenol A, etc. These phenols may be used alone, or 2 or more of them may be used in combination.

Examples of the aldehydes include formaldehyde, paraformaldehyde, furfural, benzaldehyde, nitrobenzaldehyde, and acetaldehyde. These aldehydes may be used alone, and 2 or more kinds thereof may be used in combination.

Examples of the acid catalyst include inorganic acids such as hydrochloric acid, sulfuric acid, nitric acid, phosphoric acid, and phosphorous acid; organic acids such as formic acid, oxalic acid, acetic acid, diethyl sulfuric acid, and p-toluenesulfonic acid; and metal salts such as zinc acetate.

The weight average molecular weight of the novolac resin is not particularly limited, but is preferably 500 to 50,000, and more preferably 1,500 to 15,000 from the viewpoint of resolution and spinnability.

The "weight average molecular weight" in the present invention means a molecular weight in terms of polystyrene measured by Gel Permeation Chromatography (GPC).

The dissolution inhibitor can be used without limitation as a photosensitizer conventionally used in a positive photosensitive material, and examples thereof include naphthoquinone diazo compounds such as1, 2-naphthoquinone diazo-5-sulfonate and 1, 2-naphthoquinone diazo-4-sulfonate, and preferably 1, 2-naphthoquinone diazo-5-sulfonate.

The content of the dissolution inhibitor is usually 5 to 50 parts by weight, preferably 10 to 40 parts by weight, based on 100 parts by weight of the novolak resin.

The polyvinyl phenol resin may be any one conventionally used for positive photosensitive materials, and examples thereof include resins obtained by polymerizing hydroxystyrenes in the presence of a radical polymerization initiator.

Examples of the hydroxystyrene include o-hydroxystyrene, m-hydroxystyrene, p-hydroxystyrene, 2- (o-hydroxyphenyl) propylene, 2- (m-hydroxyphenyl) propylene, and 2- (p-hydroxyphenyl) propylene. These hydroxystyrenes may be used alone or in combination of 2 or more.

Examples of the radical polymerization initiator include organic peroxides such as benzoyl peroxide, dicumyl peroxide, and dibutyl peroxide; and azobisisobutyronitrile, azobisvaleronitrile and other azobis compounds.

The weight average molecular weight of the polyvinyl phenol resin is not particularly limited, but is preferably 500 to 50,000, and more preferably 1,500 to 25,000 from the viewpoint of resolution and spinnability.

The (meth) acrylic resin may be any one conventionally used for positive photosensitive materials, and examples thereof include resins obtained by polymerizing a polymerizable monomer having a (meth) acryloyl group in the presence of a radical polymerization initiator.

Examples of the polymerizable monomer having a (meth) acryloyl group include alkyl (meth) acrylates such as methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, pentyl (meth) acrylate, hexyl (meth) acrylate, heptyl (meth) acrylate, octyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, nonyl (meth) acrylate, decyl (meth) acrylate, undecyl (meth) acrylate, dodecyl (meth) acrylate, trifluoroethyl (meth) acrylate, and tetrafluoropropyl (meth) acrylate; acrylamides such as diacetone acrylamide; tetrahydrofurfuryl (meth) acrylate, dialkylaminoethyl (meth) acrylate, glycidyl (meth) acrylate, (meth) acrylic acid, α -bromo (meth) acrylic acid, α -chloro (meth) acrylic acid, β -furyl (meth) acrylic acid, and β -styryl (meth) acrylic acid, and the like. These polymerizable monomers having a (meth) acryloyl group may be used alone, or 2 or more kinds may be used in combination.

Examples of the radical polymerization initiator include organic peroxides such as benzoyl peroxide, dicumyl peroxide, and dibutyl peroxide; and azobisisobutyronitrile, azobisvaleronitrile and other azobis compounds.

In addition to the polymerizable monomer having a (meth) acryloyl group, the (meth) acrylic resin may be copolymerized with a polymerizable styrene derivative substituted at the α -position or in an aromatic ring, such as styrene, vinyltoluene, or α -methylstyrene; vinyl alcohol esters such as acrylonitrile and vinyl-n-butyl ether; maleic acid monoesters such as maleic acid, maleic anhydride, monomethyl maleate, monoethyl maleate, and monoisopropyl maleate; 1 or 2 or more polymerizable monomers such as fumaric acid, cinnamic acid, alpha-cyanocinnamic acid, itaconic acid, crotonic acid, etc.

In the present specification, "(meth) acrylic acid" means both "acrylic acid" and "methacrylic acid".

The weight average molecular weight of the (meth) acrylic resin is not particularly limited, but is preferably 500 to 500,000, and more preferably 1,500 to 100,000 from the viewpoint of resolution and spinnability.

The polyvinyl phenol resin or the (meth) acrylic resin preferably contains a structural unit having a side chain with an alkali-soluble group protected by an acid-labile protecting group.

Examples of the acid-labile protecting group include, t-butyl, t-butoxycarbonyl, t-butoxycarbonylmethyl, t-pentyloxycarbonyl, t-pentyloxycarbonylmethyl, 1-diethylpropyloxycarbonyl, 1-diethylpropyloxycarbonylmethyl, 1-ethylcyclopentyloxycarbonyl, 1-ethylcyclopentyloxycarbonylmethyl, 1-ethyl-2-cyclopentenyloxycarbonyl, 1-ethyl-2-cyclopentenyloxycarbonylmethyl, 1-ethoxyethoxycarbonylmethyl, 2-tetrahydropyranyloxycarbonylmethyl, 2-tetrahydrofuranyloxycarbonylmethyl, tetrahydrofuran-2-yl, 2-methyltetrahydrofuran-2-yl, tetrahydropyran-2-yl, 2-methyltetrahydropyran-2-yl and the like.

Examples of the alkali-soluble group include a phenolic hydroxyl group and a carboxyl group.

The polyvinyl phenol resin or (meth) acrylic resin containing a structural unit having a side chain with an alkali-soluble group protected with an acid-labile protecting group can be produced, for example, by introducing an acid-labile protecting group into the polyvinyl phenol resin or (meth) acrylic resin by chemically reacting the alkali-soluble group with the polyvinyl phenol resin or (meth) acrylic resin. Alternatively, the resin composition can be produced by mixing a monomer corresponding to a structural unit having an alkali-soluble group protected by an acid-labile protecting group in a side chain with a raw material monomer of a polyvinyl phenol resin or a (meth) acrylic resin, and copolymerizing the resulting monomer mixture.

The photoacid generator being one which passes lightThe compound which generates an acid directly or indirectly by the action of the acid is not particularly limited, and examples thereof include diazomethane compounds, acetic acid, and acetic acid,Salt compounds, sulfonimide compounds, nitrobenzyl compounds, iron arene coordination compounds, benzoin tosylate compounds, triazine compounds containing halogen, oxime sulfonate compounds containing cyano groups, naphthalimide compounds, and the like.

The content of the photoacid generator is usually 0.1 to 50 parts by weight, preferably 3 to 30 parts by weight, based on 100 parts by weight of the polyvinyl phenol resin or the (meth) acrylic resin.

The polyvinyl phenol resin or (meth) acrylic resin containing a structural unit having a photoacid generating group in a side chain can be produced, for example, by mixing the photoacid generator as a monomer with a raw material monomer of the polyvinyl phenol resin or (meth) acrylic resin and copolymerizing the resulting monomer mixture.

The weight average molecular weight of the polyvinyl phenol resin containing a structural unit having a photoacid generating group in a side chain is not particularly limited, but is preferably 500 to 50,000, and more preferably 1,500 to 25,000 from the viewpoint of resolution and spinnability.

The weight average molecular weight of the (meth) acrylic resin containing a structural unit having a photoacid generating group in a side chain is not particularly limited, but is preferably 500 to 500,000, and more preferably 1,500 to 10,000 from the viewpoint of resolution and spinnability.

The positive photosensitive material may be produced by a method known per se, and for example, a positive photosensitive material (positive photoresist) containing (i) a novolak resin and a dissolution inhibitor may be produced by a method described in Japanese patent publication No. 7-66184, etc., a positive photosensitive material (positive photoresist) containing (ii) a polyvinyl phenol resin or an acrylic resin and a photoacid generator may be produced by a method described in Japanese patent publication No. 7-66184, Japanese patent publication No. 2007-79589, or Japanese patent publication No. 10-207066, etc., and a positive photosensitive material (positive photoresist) containing (iii) a polyvinyl phenol resin or an acrylic resin containing a structural unit having a photoacid generating group at a side chain may be produced by Japanese patent publication No. 9-189998, Japanese patent publication No. 2002-72483, The method described in, for example, Japanese patent application laid-open No. 2010-85971 or No. 2010-256856. Alternatively, commercially available products may be used.

The positive photosensitive material (iv) can be produced by the method described in japanese patent No. 5093525, for example.

The fiber of the present invention is suitably produced by spinning a composition for producing a photosensitive fiber, which contains a positive photosensitive material and a solvent.

The solvent is not particularly limited as long as it can uniformly dissolve or disperse the positive photosensitive material and does not react with each material, but is preferably a polar solvent.

Examples of the polar solvent include water, methanol, ethanol, 2-propanol, propylene glycol monomethyl ether acetate, acetone, dimethylformamide, dimethylacetamide, N-methylpyrrolidone, and hexafluoroisopropanol, and propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, and hexafluoroisopropanol are preferable from the viewpoint of ease of spinning of the composition for producing a photosensitive fiber.

The solvent may be used alone, or 2 or more kinds may be used in combination.

The fiber of the present invention is suitably produced by spinning a composition for producing a photosensitive fiber (hereinafter, also simply referred to as "the composition of the present invention") containing a positive photosensitive material, a solvent, and an electrolyte.

Examples of the electrolyte include tetrabutylammonium chloride.

The content of the positive photosensitive material in the composition of the present invention is preferably 60 to 100% by weight, more preferably 60 to 95% by weight, and particularly preferably 70 to 90% by weight, based on the solid content of the composition for producing a photosensitive fiber other than the solvent, from the viewpoints of resolution and spinning property.

The composition of the present invention may contain, if necessary, additives generally used in compositions for producing fibers, in addition to the positive photosensitive material, as long as the object of the present invention is not significantly impaired. Examples of the additive include a surfactant, a rheology modifier, a drug, and fine particles.

The composition of the present invention is prepared by mixing a positive photosensitive material with a solvent or further mixing the additive with the solvent. The mixing method is not particularly limited as long as the mixing is performed by a method known per se or a method based on a method known per se.

The method for spinning the composition of the present invention is not particularly limited as long as it can form a fiber, and examples thereof include a melt blowing method, a composite melt spinning method, an electrospinning method, and the like.

The electrospinning method is a known spinning method and can be carried out using a known electrospinning device. The speed (discharge speed) at which the composition of the present invention is discharged from the tip of a nozzle (e.g., needle, etc.); applying a voltage; various conditions such as the distance from the tip of the nozzle for discharging the composition of the present invention to the substrate receiving the composition (discharge distance) can be appropriately set according to the diameter of the fiber to be produced. The discharge rate is usually 0.1 to 100. mu.l/min, preferably 0.5 to 50. mu.l/min, and more preferably 1 to 20. mu.l/min. The applied voltage is usually 0.5 to 80kV, preferably 1 to 60kV, and more preferably 3 to 40 kV. The discharge distance is usually 1 to 60cm, preferably 2 to 40cm, and more preferably 3 to 30 cm.

Further, the electrospinning method can be performed using a roll collector or the like. The orientation of the fibers can be controlled by using a roll collector or the like. For example, a nonwoven fabric or the like can be obtained when the drum is rotated at a low speed, and an oriented fiber sheet or the like can be obtained when the drum is rotated at a high speed. It is effective for the production of an etching mask material or the like when processing a semiconductor material (for example, a substrate or the like).

The method for producing a fiber of the present invention may further include a step of heating the spun fiber at a specific temperature in addition to the spinning step. The fibers used need to be in close contact with the conductive layer because they function as a mask for the conductive layer. If the adhesion is insufficient, defects such as disconnection of the resulting fiber network structure may occur, and the conductivity may be lowered. As a method for improving the adhesion of the applied fiber to the conductive layer, for example, heating under a temperature condition of the glass transition temperature of the fiber or higher is effective.

The temperature for heating the spun fiber is usually in the range of 70 to 300 ℃, preferably 80 to 250 ℃, and more preferably 90 to 200 ℃.

The method of heating the spun fiber is not particularly limited as long as it can be heated at the above-mentioned heating temperature, and the fiber can be appropriately heated by a method known per se or a method based on a method known per se. Specific examples of the heating method include a method using an electric heating plate, an oven, or the like under the atmosphere.

The time for heating the spun fiber can be appropriately set depending on the heating temperature and the like, but from the viewpoint of the crosslinking reaction rate and the production efficiency, the time is preferably 1 minute to 48 hours, more preferably 5 minutes to 36 hours, and particularly preferably 10 minutes to 24 hours.

The fiber of the present invention has photosensitivity. Therefore, the method can be used for manufacturing an etching mask material, a medical material, a cosmetic material, or the like when processing a semiconductor material (for example, a substrate or the like). In particular, nanofibers and microfibers can be suitably used for the production of etching masks having fine pores, cell culture substrates having patterns (biomimetic substrates, for example, substrates for co-culture with vascular cells and the like for preventing the degradation of cultured cells), and the like.

2. Photosensitive fiber pattern and method for producing substrate having photosensitive fiber pattern

Since the fiber of the present invention has photosensitivity, a fiber layer in which fibers are gathered is formed, and the fiber layer is directly subjected to a photolithography process, and thus the fiber of the present invention is a positive photosensitive fiber, and therefore, a fiber pattern in which fibers in an exposed portion are solubilized and removed and fibers in an unexposed portion remain is formed. By performing a photolithography process on the fiber layer of the nanofibers and/or microfibers, a complicated and fine fiber pattern can be formed.

The fibers in the fiber layer are assembled in a one-dimensional, two-dimensional or three-dimensional state, and the assembled state may or may not have regularity. In the present invention, the "pattern" means a substance that is recognized as a form of a space object, such as a pattern or a pattern mainly composed of straight lines, curved lines, and a combination thereof. The pattern may have any shape, and the pattern itself may or may not have regularity.

The invention provides a method for forming a photosensitive fiber pattern, which comprises the following steps: a step 1 of spinning the photosensitive fiber-producing composition on a substrate to form a fiber layer made of a photosensitive fiber (preferably, the fiber of the present invention); a 2 nd step of exposing the fiber layer through a mask; and a 3 rd step of forming a photosensitive fiber pattern by developing the fiber layer with a developer. This method can also be referred to as a method of manufacturing a fiber pattern. Further, since the base material with the fiber pattern can be manufactured by this method, this method can also be referred to as a method for manufacturing a base material with a fiber pattern.

[ step 1 ]

The 1 st step is a step of spinning the composition for producing a photosensitive fiber on a substrate to form a fiber layer made of a photosensitive fiber (preferably, the fiber of the present invention).

The method for forming a fiber layer composed of a photosensitive fiber (preferably, the fiber of the present invention) on a substrate is not particularly limited, and for example, the composition of the present invention may be directly spun on a substrate to form a fiber layer.

The substrate is not particularly limited as long as it is a substrate of a material that does not deform or modify the lithographic process, and examples thereof include a semiconductor such as resin, glass, ceramic, plastic, or silicon, a film, a sheet, a plate, a cloth (woven fabric, knitted fabric, nonwoven fabric), and a thread.

The resin as a material of the base material may be any of natural resins and synthetic resins. As the natural resin, Cellulose Triacetate (CTA), cellulose immobilized with dextran sulfate, or the like is preferably used, and as the synthetic resin, Polyacrylonitrile (PAN), polyester polymer alloy (PEPA), Polystyrene (PS), Polysulfone (PSF), polymethyl methacrylate (PMMA), polyvinyl alcohol (PVA), Polyurethane (PU), Ethylene Vinyl Alcohol (EVAL), Polyethylene (PE), Polyester (PE) (for example, polyethylene terephthalate (PET)), polypropylene (PP), poly 1, 1-difluoroethylene (PVDF), various ion exchange resins, Polyether Sulfone (PEs), or the like is preferably used in order to have repeated flexibility (bending resistance) described later, and among the Polyester (PE), polyethylene terephthalate (PET) is particularly preferable.

The basis weight (the amount of the fibers supported per unit area on the base material) of the fiber layer after the pattern formation is not particularly limited, and may be, for example, an amount for forming a fiber layer having a thickness of about 5 to 50 μm.

[ 2 nd step ]

The 2 nd step is a step of exposing the fibers formed on the base material in the 1 st step through a mask. The exposure can be performed by, for example, g-ray (wavelength 436nm), h-ray (wavelength 405nm), i-ray (wavelength 365nm), a mercury lamp, various lasers (e.g., excimer lasers such as KrF excimer laser (wavelength 248nm), ArF excimer laser (wavelength 193nm), and F2 excimer laser (wavelength 157 nm)), EUV (extreme ultraviolet, wavelength 13nm), and LED.

After the photosensitive fiber is exposed to light, the fiber may be heated (Post Exposure Bake: PEB) as necessary. The heating temperature may be appropriately set according to the heating time, but is usually 80 to 200 ℃. The heating time may be appropriately set according to the heating temperature, but is usually 1 to 20 minutes.

[ 3 rd step ]

The 3 rd step is a step of developing the fiber exposed in the 2 nd step and heated as necessary with a developer. As the developer, a developer generally used for patterning a photosensitive composition can be suitably used. The developer used in the above-mentioned step 3 more preferably contains water or an organic solvent.

The water may be used alone or in various aqueous alkaline solutions (for example, aqueous alkaline solutions such as inorganic bases including sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, and aqueous ammonia, primary amines including ethylamine and N-propylamine, secondary amines including diethylamine and di-N-butylamine, tertiary amines including triethylamine and methyldiethylamine, ethanolamines including dimethylethanolamine and triethanolamine, quaternary ammonium salts including tetramethylammonium hydroxide, tetraethylammonium hydroxide, and choline, cyclic amines including pyrrole and piperidine, and the like).

Examples of the organic solvent include alcohols (e.g., 1-butanol, 2-butanol, isobutanol, t-butanol, 1-pentanol, 2-pentanol, 3-pentanol, 1-heptanol, 2-heptanol, t-pentanol, neopentyl alcohol, 2-methyl-1-propanol, 2-methyl-1-butanol, 2-methyl-2-butanol, 3-methyl-1-butanol, 3-methyl-3-pentanol, cyclopentanol, 1-hexanol, 2-hexanol, 3-hexanol, 2, 3-dimethyl-2-butanol, 3-dimethyl-1-butanol, 3-dimethyl-2-butanol, 2-diethyl-1-butanol, and mixtures thereof, 2-methyl-1-pentanol, 2-methyl-2-pentanol, 2-methyl-3-pentanol, 3-methyl-1-pentanol, 3-methyl-2-pentanol, 3-methyl-3-pentanol, 4-methyl-1-pentanol, 4-methyl-2-pentanol, 4-methyl-3-pentanol, 1-butoxy-2-propanol, and cyclohexanol, and the like) and a solvent (for example, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, methyl cellosolve acetate, ethyl cellosolve acetate, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, propylene glycol monomethyl ether acetate, and the like) used for a general resist composition and the like, Propylene glycol propyl ether acetate, toluene, xylene, methyl ethyl ketone, cyclopentanone, cyclohexanone, ethyl 2-hydroxypropionate, ethyl 2-hydroxy-2-methylpropionate, ethyl ethoxyacetate, ethyl glycolate, methyl 2-hydroxy-3-methylbutyrate, methyl 3-methoxypropionate, ethyl 3-ethoxypropionate, methyl pyruvate, ethyl acetate, butyl acetate, ethyl lactate, butyl lactate, etc.), and the like.

The developer used in step 3 is preferably water, an aqueous solution of ethyl lactate or tetramethylammonium hydroxide, and particularly preferably water or ethyl lactate. The pH of the developer is preferably near neutral or alkaline, and the developer may contain an additive such as a surfactant.

The photosensitive fiber pattern of the present invention produced on the substrate through the above-described steps is used together with the substrate or separated from the substrate.

When the photosensitive fiber pattern of the present invention is used together with a substrate, the substrate (i.e., the substrate having the photosensitive fiber pattern of the present invention on the surface) can be suitably used as an etching mask, a cell culture scaffold material, or the like used for processing a substrate such as a semiconductor, as long as the photosensitive fiber pattern of the present invention is formed of nanofibers and/or microfibers. In the case of using the substrate having the photosensitive fiber pattern of the present invention on the surface as a cell culture scaffold material, the substrate is preferably glass or plastic.

3. Metal pattern and method for manufacturing base material with metal pattern

The present invention can provide a method for manufacturing a metal pattern, including the steps of: a step 1 of forming a fiber layer composed of a photosensitive fiber (preferably, the fiber of the present invention) on a substrate having a metal layer on the surface thereof; a 2 nd step of exposing the fiber layer through a mask; a 3 rd step of forming a photosensitive fiber pattern by developing the fiber layer with a developer; and a 4 th step of etching the metal layer with an etching solution to further remove the photosensitive fiber, thereby forming a metal pattern.

The difference between the 1 st step of the method for manufacturing a metal pattern and the 1 st step of the method for manufacturing a photosensitive fiber pattern is a portion having a metal layer on the surface of a base material.

[ step 1 ]

The 1 st step is a step of forming a fiber layer made of a photosensitive fiber on a substrate having a metal layer on the surface thereof.

Examples of the metal include metals such as cobalt, nickel, copper, zinc, chromium, molybdenum, ruthenium, rhodium, palladium, silver, cadmium, osmium, titanium, iridium, platinum, gold, and aluminum, and alloys of these metals, but the metal pattern of the present invention is not limited thereto, and can be applied to any conductive metal. In addition, in order to provide a transparent conductive film using the metal pattern of the present invention, copper, silver, and aluminum are preferable from the viewpoint of conductivity, and in order to provide a flexible transparent electrode (transparent conductive film), a metal or an alloy such as aluminum and copper is preferable, and further in order to achieve light weight and low cost, aluminum is more preferable.

[ 2 nd step ]

The 2 nd step is a step of exposing the fibers formed on the base material having the metal layer on the surface thereof in the 1 st step through a mask.

The exposure light and the post-exposure fiber heating in the 2 nd step can be referred to the contents described in the 2 nd step of the above-mentioned "2".

[ 3 rd step ]

The 3 rd step is a step of developing the fiber exposed in the 2 nd step and heated as necessary with a developer.

The developer used in the 3 rd step can be referred to as described in the 3 rd step of the above-mentioned "2".

[ 4 th step ]

The 4 th step is a step of etching the metal layer corresponding to the fiber layer portion developed in the 3 rd step with an etching solution to further remove the photosensitive fiber, thereby forming a metal pattern.

As a method for removing the metal layer region not covered with the fibers by etching, although it depends on the characteristics of the metal forming the metal layer, there is a wet method in which the metal is dissolved in an acidic aqueous solution such as hydrochloric acid or nitric acid, or an aqueous solution of sodium hydroxide or potassium hydroxide by ionizing or complex ionizing the metal. The immersion time, temperature, and the like may be appropriately selected depending on the type and concentration of the aqueous solution used and the type and thickness of the metal layer to be dissolved, and may be replaced with a dry method using an organic gas or a halogen gas, if necessary.

After the region of the metal layer not coated with the photosensitive fiber is removed, it is preferable to sufficiently wash the substrate including the metal pattern coated with the photosensitive fiber with water or the like in order to remove impurities such as a compound obtained by ionizing or complexing the metal and a solute contained in an aqueous solution. Then, the photosensitive fiber covering the metal pattern is removed. The photosensitive fiber can be usually completely removed with an organic solvent. For example, it can be removed with acetone.

Thus, a metal pattern having a fine mesh structure of metal, that is, a mesh-like metal pattern, or a wiring pattern having the mesh-like metal pattern as wiring can be formed on the substrate.

After the removal of the photosensitive fiber, the light transmittance of the metal mesh pattern in the visible light wavelength region is, for example, 5% or more, for example, 8% or more, for example, 10% or more, for example, 15% or more, for example, 20% or more, for example, 30% or more, for example, 40% or more, for example, 50% or more, for example, 60% or more.

The metal pattern of the present invention produced on the base material through the above-described steps is used together with the base material or separated from the base material. When used together with a substrate, the substrate is provided with a metal pattern.

< repeated flexibility (bending resistance) >

The metal pattern and the base material with the metal pattern have resistance to repeated bending. Specifically, even when the metal pattern is bent with a bending radius of 2mm as described in the examples, for example, 2 or more, 5 or more, 10 or more, 50 or more, 100 or more, or 200 or more times, the rate of change in sheet resistance of the metal pattern is small (for example, the rate of change in sheet resistance is within 10% compared to before bending).

Examples of the relationship among the light transmittance, the sheet resistance value, and the fiber coverage include the following combinations, but are not limited thereto.

When the light transmittance of the mesh-like metal pattern in the wavelength region of visible light is 5 to 11%, the sheet resistance value is 5 to 9 Ω/□, and the fiber coverage is 75 to 90%, and when the light transmittance of the mesh-like metal pattern in the wavelength region of visible light is 12% or more (for example, 15% or more, for example, 20% or more, for example, 30% or more, for example, 40% or more, for example, 50% or more, for example, 60% or more), the sheet resistance value is 10 to 500 Ω/□, and the fiber coverage is 1 to 70%.

Examples

Specific examples of the present invention will be described below, but the present invention is not limited to these specific examples.

[ measurement of weight average molecular weight ]

In this example, the weight average molecular weight of the polymer was determined by Gel Permeation Chromatography (GPC). The apparatus and measurement conditions used for the measurement are as follows.

The device comprises the following steps: TOSOH HLC-8320GPC system

Column: shodex (registered trademark) KF-803L, KF-802 and KF-801

Column temperature: 40 deg.C

Eluent: DMF (dimethyl formamide)

Flow rate: 0.6 ml/min

A detector: RI (Ri)

Standard sample: polystyrene

"example 1"

Production of copolymer

10g of benzyl acrylate and 1.12g of acrylic acid were dissolved in 50ml of tetrahydrofuran, and nitrogen bubbling was performed for 10 minutes. Subsequently, 0.018g of dimethyl 2, 2' -azobis (isobutyrate) was added as a polymerization initiator, and polymerization was carried out for 6 hours under nitrogen atmosphere and heating reflux at 70 ℃. After the polymerization, the solution was poured into 1L of n-hexane to precipitate a polymer, which was then separated by filtration and dried to obtain a white polymer. The structure of the obtained polymer was found to be a polymer having a molar fraction of benzyl acrylate structure of 80% and a molar fraction of acrylic acid structure of 20% by various analytical methods. The molecular weight of the polymer in tetrahydrofuran was examined by Gel Permeation Chromatography (GPC) in terms of polystyrene, and the weight average molecular weight (Mw) was 25,900.

Production of composition for producing photosensitive fiber

10g of the copolymer, 3g of a dissolution inhibitor (naphthoquinone diazosulfonate compound), and 0.1g of an electrolyte (tetrabutylammonium chloride) were dissolved in 40g of an organic solvent (hexafluoroisopropanol), to prepare a positive photosensitive fiber-producing composition. In addition, the glass transition temperature of the solid component obtained by drying and removing the solvent component from the composition was examined by a Differential Scanning Calorimeter (DSC), and the glass transition temperature was 28.5 ℃.

< c. method for producing fiber by electrospinning

In this example, fibers produced by the electrospinning method were used エスプレイヤー ES-2000 (manufactured by フューエンス). The fiber-producing composition was injected into a 1ml lock glass syringe (manufactured by アズワン K.K.) equipped with a lock metal needle 24G (manufactured by K.K.: 12456 ンジニアリング) having a needle length of 13 mm. The distance from the needle tip to the fiber-receiving substrate (discharge distance) was set to 10cm, the applied voltage was set to 5kV, the discharge speed was set to 10. mu.l/min, and the discharge time was set to 5 seconds. The temperature in the laboratory during electrospinning was set at 23 ℃.

< d. patterning of photosensitive fiber >

The photosensitive fiber-producing composition was spun by an electrospinning method onto the surface of an aluminum deposited film of a still-standing aluminum deposited PET film (the thickness of the PET film was 12 μm, and the thickness of the aluminum deposited film was 50nm), to form a fiber layer formed by winding fibers having a diameter of about 300 nm. At this time, the coverage (the ratio of the fibers of the fiber layer covering the aluminum-deposited PET film) was about 40%. Subsequently, the fiber layer was heated in an oven at 40 ℃ for 5 minutes to adhere the fiber layer and the aluminum deposited PET film by removing the residual solvent in the fiber layer and by heat sagging of the fibers. Next, using an ultrahigh pressure mercury lamp as a light source, the fiber layer was subjected to contact exposure through a photomask on which a circuit pattern including a wiring pattern having a minimum line width of 50 μm was drawn. Exposure wavelength is set to 350-450 nm, exposure amount is measured at i-ray wavelength and set to 1000mJ/cm². After exposure of the fibre layer, in a developer (alkaline aqueous solution containing a metal corrosion inhibitor (tetramethyl)Ammonium hydroxide 0.0238%) for 2 minutes, followed by rinsing with pure water for 5 minutes. Then, the resultant was dried by heating in an oven at 40 ℃ for 5 minutes to obtain a fiber layer having a wiring pattern with a line width of 50 μm on an aluminum-deposited PET film.

Etching of aluminum-deposited PET film

The aluminum vapor deposited PET film on which the fiber layer having the wiring pattern with a line width of 50 μm was formed was immersed in an aluminum etching solution Pure Etch AS1 (phosphoric acid/nitric acid/acetic acid system, manufactured by linkon chemical industries, ltd.), and wet etching of aluminum was performed with the fiber layer AS an etching mask (25 ℃,5 minutes). When the fiber layer was completely removed with an organic solvent (acetone), a circuit pattern including a wiring pattern having a minimum line width of 50 μm, which is constituted by a mesh-like network structure of fine aluminum having a line width of about 300nm, was formed on the PET film.

Electrical/optical/mechanical characteristics of wiring pattern < f >

The electrical characteristics of the circuit pattern portion constituted by a fine mesh network structure of aluminum having a line width of about 300nm were measured by a 4-terminal resistance measurement method. As a result, it was confirmed that the sheet showed conductivity and the sheet resistance was about 10. omega./□. At this time, anisotropy of the conductivity was not observed. Next, the optical characteristics were measured/observed by an ultraviolet-visible spectrophotometer and visual observation. As a result, the portion of the wiring pattern formed by the mesh-like metal pattern showed a light transmittance of about 60% in a visible light wavelength range of 380nm to 780nm, and was visually confirmed to be transparent. Next, a bending test was performed with a bending radius of 2 mm. Even when the bending was performed 100 times, the sheet resistance did not change, and high conductivity could be maintained.

"example 2"

Production of copolymer

10g of 4-hydroxyphenyl methacrylate, 20.04g of benzyl acrylate, and 7.92g of benzyl methacrylate were dissolved in 120ml of tetrahydrofuran, and nitrogen bubbling was performed for 10 minutes. Subsequently, 0.26g of dimethyl 2, 2' -azobis (isobutyrate) was added as a polymerization initiator, and the mixture was heated under reflux at 70 ℃ in a nitrogen atmosphere to conduct polymerization for 6 hours. After the polymerization, a solution was poured into 2l of n-hexane to precipitate a polymer, which was then separated by filtration and dried to obtain a white polymer. The structure of the obtained polymer was found to be a polymer having a mole fraction of 4-hydroxyphenyl methacrylate structure of 25%, benzyl acrylate structure of 55%, and benzyl methacrylate structure of 20% by various analytical methods. The molecular weight of the polymer in tetrahydrofuran was examined by Gel Permeation Chromatography (GPC) in terms of polystyrene, and the weight average molecular weight (Mw) was 31,000.

Production of composition for producing photosensitive fiber

10g of the copolymer, 3g of a dissolution inhibitor (naphthoquinone diazosulfonate compound), and 0.5g of an electrolyte (tetrabutylammonium chloride) were dissolved in 90g of an organic solvent (hexafluoroisopropanol), to prepare a positive photosensitive fiber-producing composition. Further, the glass transition temperature of the solid content obtained by drying and removing the solvent component from the composition was examined by a Differential Scanning Calorimeter (DSC), and the glass transition temperature was 85.6 ℃.

< c. method for producing fiber by electrospinning

In this example, fibers produced by the electrospinning method were used エスプレイヤー ES-2000 (manufactured by フューエンス). The fiber-producing composition was injected into a 1ml lock glass syringe (manufactured by アズワン K.K.) equipped with a lock metal needle 24G (manufactured by K.K.: 12456 ンジニアリング) having a needle length of 13 mm. The distance from the needle tip to the fiber-receiving substrate (discharge distance) was set to 20cm, the applied voltage was set to 5kV, the discharge speed was set to 10. mu.l/min, and the discharge time was set to 5 seconds. The temperature in the laboratory during electrospinning was set at 23 ℃.

< d. patterning of photosensitive fiber >

The photosensitive fiber-producing composition was spun by an electrospinning method onto the surface of an aluminum deposited film of a still-standing aluminum deposited PET film (thickness of PET film: 12 μm, thickness of aluminum deposited film: 50nm), to form a fiber layer formed by winding fibers having a diameter of about 500 nm. At this time, the coverage (the fiber of the fiber layer covered with the aluminum-deposited PET film)Proportion) was about 20%. Subsequently, the fiber layer was heated in an oven at 90 ℃ for 5 minutes to adhere to the aluminum deposited PET film by removing the residual solvent in the fiber layer and by thermally sagging the fibers. Next, using an ultrahigh pressure mercury lamp as a light source, the fiber layer was subjected to contact exposure through a mask on which a circuit pattern including a wiring pattern having a minimum line width of 50 μm was drawn. Exposure wavelength is set to 350-450 nm, exposure amount is measured at i-ray wavelength and is set to 280mJ/cm². After the exposure of the fiber layer, the fiber layer was exposed to a developer (an alkaline aqueous solution containing a metal corrosion inhibitor (tetramethylammonium hydroxide, 3.3%) for 2 minutes, followed by rinsing with pure water for 5 minutes, and then dried by heating in an oven at 40 ℃ for 5 minutes to obtain a fiber layer having a wiring pattern with a line width of 50 μm on an aluminum-deposited PET film.

Etching of aluminum-deposited PET film

The aluminum vapor deposited PET film on which the fiber layer having the wiring pattern with a line width of 50 μm was formed was immersed in an aluminum etching solution Pure Etch AS1 (phosphoric acid/nitric acid/acetic acid system, manufactured by linkon chemical industries, ltd.), and wet etching of aluminum was performed with the fiber layer AS an etching mask (25 ℃,1 minute). When the fiber layer was completely removed with an organic solvent (acetone), a circuit pattern including a wiring pattern having a minimum line width of 50 μm, which is constituted by a mesh-like network structure of fine aluminum having a line width of about 500nm, was formed on the PET film.

Electrical/optical/mechanical characteristics of wiring pattern < f >

The electrical characteristics of the circuit pattern portion constituted by a fine mesh network structure of aluminum having a line width of about 500nm were measured by a 4-terminal resistance measurement method. As a result, it was confirmed that the sheet showed conductivity and the sheet resistance was about 20. omega./□. At this time, the conductivity was not anisotropic. Next, the optical characteristics were measured/observed by an ultraviolet-visible spectrophotometer and visual observation. As a result, the portion of the wiring pattern formed by the mesh-like metal pattern showed a light transmittance of about 65% in a visible light wavelength range of 380nm to 780nm, and was visually confirmed to be transparent. Next, a bending test was performed with a bending radius of 2 mm. Even when the bending was performed 100 times, the sheet resistance did not change, and high conductivity could be maintained.

"example 3" (when the ratio of the fiber layer to the aluminum deposited PET film (coverage) is low)

A method for producing a fiber by electrospinning

In this example, fibers produced by the electrospinning method were used エスプレイヤー ES-2000 (manufactured by フューエンス). The fiber-producing composition was injected into a 1ml lock glass syringe (manufactured by アズワン K.K.) equipped with a lock metal needle 24G (manufactured by K.K.: 12456 ンジニアリング) having a needle length of 13 mm. The distance from the needle tip to the fiber-receiving substrate (discharge distance) was set to 20cm, the applied voltage was set to 5kV, the discharge speed was set to 10. mu.l/min, and the discharge time was set to 1 second. The temperature in the laboratory during electrospinning was set at 23 ℃.

Patterning of photosensitive fibers

The composition for producing photosensitive fibers adjusted so as to satisfy the requirement < b > in example 2 was spun by an electrospinning method onto the surface of an aluminum deposited film of a still-standing aluminum deposited PET film (thickness of PET film 12 μm, thickness of aluminum deposited film 50nm), to form a fiber layer formed by winding fibers having a diameter of about 500 nm. At this time, the coverage (the ratio of the fibers of the fiber layer covering the aluminum-deposited PET film) was about 3%. Subsequently, the fiber layer was heated in an oven at 90 ℃ for 5 minutes to adhere to the aluminum deposited PET film by removing the residual solvent in the fiber layer and by thermally sagging the fibers. Next, using an ultrahigh pressure mercury lamp as a light source, the fiber layer was subjected to contact exposure through a photomask on which a circuit pattern including a wiring pattern having a minimum line width of 50 μm was drawn. Exposure wavelength is set to 350-450 nm, exposure amount is measured at i-ray wavelength and is set to 280mJ/cm². After the exposure of the fiber layer, the fiber layer was exposed to a developer (an alkaline aqueous solution containing a metal corrosion inhibitor (tetramethylammonium hydroxide, 3.3%) for 2 minutes, followed by rinsing with pure water for 5 minutes, and then dried by heating in an oven at 40 ℃ for 5 minutes to obtain a fiber layer having a wiring pattern with a line width of 50 μm on an aluminum-deposited PET film。

Etching of aluminum-deposited PET film

The aluminum vapor deposited PET film on which the fiber layer having the wiring pattern with a line width of 50 μm was formed was immersed in an aluminum etching solution Pure Etch AS1 (phosphoric acid/nitric acid/acetic acid system, manufactured by linkon chemical industries, ltd.), and wet etching of aluminum was performed with the fiber layer AS an etching mask (25 ℃,1 minute). Then, the fiber layer was completely removed with an organic solvent (acetone), and a circuit pattern including a wiring pattern having a minimum line width of 50 μm, which is constituted by a mesh-like network structure of fine aluminum having a line width of about 500nm, was formed on the PET film.

Electrical/optical/mechanical characteristics of wiring pattern < d >

The electrical characteristics of the circuit pattern portion constituted by a fine mesh network structure of aluminum having a line width of about 500nm were measured by a 4-terminal resistance measurement method. As a result, it was confirmed that the sheet showed conductivity and the sheet resistance was about 250. omega./□. Next, the optical characteristics were measured/observed by an ultraviolet-visible spectrophotometer and visual observation. As a result, the wiring pattern formed by the mesh-like metal pattern exhibited a light transmittance of about 87% in a visible light wavelength range of 380nm to 780nm in the mesh-like metal pattern portion. Next, a bending test was performed with a bending radius of 2 mm. Even when 100 times of bending was performed, no change was observed in sheet resistance, and high conductivity was maintained.

"example 4" (when the ratio of the fiber layer to the aluminum deposited PET film (coverage) is high)

A method for producing a fiber by electrospinning

In this example, fibers produced by the electrospinning method were used エスプレイヤー ES-2000 (manufactured by フューエンス). The fiber-producing composition was injected into a 1ml lock glass syringe (manufactured by アズワン K.K.) equipped with a lock metal needle 24G (manufactured by K.K.: 12456 ンジニアリング) having a needle length of 13 mm. The distance from the needle tip to the fiber-receiving substrate (discharge distance) was set to 20cm, the applied voltage was set to 5kV, the discharge speed was set to 10. mu.l/min, and the discharge time was set to 20 seconds. The temperature in the laboratory during electrospinning was set at 23 ℃.

Patterning of photosensitive fibers

The composition for producing photosensitive fibers adjusted so as to satisfy the requirement < b > in example 2 was spun by an electrospinning method onto the surface of an aluminum deposited film of a still-standing aluminum deposited PET film (thickness of PET film 12 μm, thickness of aluminum deposited film 50nm), to form a fiber layer formed by winding fibers having a diameter of about 500 nm. At this time, the coverage (the ratio of the fibers of the fiber layer covering the aluminum-deposited PET film) was about 80%. Subsequently, the fiber layer was heated in an oven at 90 ℃ for 5 minutes to adhere to the aluminum deposited PET film by removing the residual solvent in the fiber layer and by thermally sagging the fibers. Next, using an ultrahigh pressure mercury lamp as a light source, the fiber layer was subjected to contact exposure through a photomask on which a circuit pattern including a wiring pattern having a minimum line width of 50 μm was drawn. Exposure wavelength is set to 350-450 nm, exposure amount is measured at i-ray wavelength and is set to 280mJ/cm². After the exposure of the fiber layer, the fiber layer was exposed to a developer (an alkaline aqueous solution containing a metal corrosion inhibitor (tetramethylammonium hydroxide, 3.3%) for 2 minutes, followed by rinsing with pure water for 5 minutes, and then dried by heating in an oven at 40 ℃ for 5 minutes to obtain a fiber layer having a wiring pattern with a line width of 50 μm on an aluminum-deposited PET film.

Etching of aluminum-deposited PET film

The aluminum vapor deposited PET film on which the fiber layer having the wiring pattern with a line width of 50 μm was formed was immersed in an aluminum etching solution Pure Etch AS1 (phosphoric acid/nitric acid/acetic acid system, manufactured by linkon chemical industries, ltd.), and wet etching of aluminum was performed with the fiber layer AS an etching mask (25 ℃,1 minute). Then, when the fiber layer was completely removed with an organic solvent (acetone), a circuit pattern including a wiring pattern having a minimum line width of 50 μm, which is constituted by a mesh-like network structure of fine aluminum having a line width of about 500nm, was formed on the PET film.

Electrical/optical/mechanical characteristics of wiring pattern < d >

The electrical characteristics of the circuit pattern portion constituted by a fine mesh network structure of aluminum having a line width of about 500nm were measured by a 4-terminal resistance measurement method. As a result, it was confirmed that the sheet showed conductivity and the sheet resistance was about 8. omega./□. Next, the optical characteristics were measured/observed by an ultraviolet-visible spectrophotometer and visual observation. As a result, the wiring pattern formed by the mesh-like metal pattern exhibited a light transmittance of about 10% in a visible light wavelength range of 380nm to 780nm in the mesh-like metal pattern portion. Next, a bending test was performed with a bending radius of 2 mm. Even when 100 times of bending was performed, no change was observed in sheet resistance, and high conductivity was maintained.

"example 5" (case where the diameter of the fiber is large)

Production of composition for producing photosensitive fiber

10g of the copolymer synthesized in < a > of example 2, 3g of a dissolution inhibitor (naphthoquinone diazosulfonate compound), and 0.5g of an electrolyte (tetrabutylammonium chloride) were dissolved in 40g of an organic solvent (hexafluoroisopropanol) to prepare a positive photosensitive fiber-producing composition.

Production method of fiber by electrospinning

In this example, fibers produced by the electrospinning method were used エスプレイヤー ES-2000 (manufactured by フューエンス). The fiber-producing composition was injected into a 1ml lock glass syringe (manufactured by アズワン K.K.) equipped with a lock metal needle 24G (manufactured by K.K.: 12456 ンジニアリング) having a needle length of 13 mm. The distance from the needle tip to the fiber-receiving substrate (discharge distance) was set to 20cm, the applied voltage was set to 5kV, the discharge speed was set to 10. mu.l/min, and the discharge time was set to 5 seconds. The temperature in the laboratory during electrospinning was set at 23 ℃.

< c. Pattern formation of photosensitive fiber >

The photosensitive fiber-producing composition was spun by an electrospinning method onto the surface of an aluminum deposited film of a still-standing aluminum deposited PET film (thickness of PET film 12 μm, thickness of aluminum deposited film 50nm), to form a fiber layer formed by winding fibers having a diameter of about 2 μm. At this time, the coverage (the ratio of the fibers of the fiber layer covering the aluminum-deposited PET film) was about 20%. Then, the fiber layer was heated in an oven at 90 ℃ for 5 minutes using the residual solvent in the fiber layerThe agent was removed and the fibers were thermally sagging, so that the fiber layer was in close contact with the aluminum deposited PET film. Next, using an ultrahigh pressure mercury lamp as a light source, the fiber layer was subjected to contact exposure through a photomask on which a circuit pattern including a wiring pattern having a minimum line width of 50 μm was drawn. Exposure wavelength is set to 350-450 nm, exposure amount is measured at i-ray wavelength and is set to 280mJ/cm². After the exposure of the fiber layer, the fiber layer was exposed to a developer (an alkaline aqueous solution containing a metal corrosion inhibitor (tetramethylammonium hydroxide, 3.3%) for 2 minutes, followed by rinsing with pure water for 5 minutes, and then dried by heating in an oven at 40 ℃ for 5 minutes to obtain a fiber layer having a wiring pattern with a line width of 50 μm on an aluminum-deposited PET film.

Etching of aluminum-deposited PET film >

The aluminum vapor deposited PET film on which the fiber layer having the wiring pattern with a line width of 50 μm was formed was immersed in an aluminum etching solution Pure Etch AS1 (phosphoric acid/nitric acid/acetic acid system, manufactured by linkon chemical industries, ltd.), and wet etching of aluminum was performed with the fiber layer AS an etching mask (25 ℃,1 minute). When the fiber layer was completely removed with an organic solvent (acetone), a circuit pattern including a wiring pattern having a minimum line width of 50 μm, which is constituted by a mesh-like network structure of aluminum having a line width of about 2 μm, was formed on the PET film.

Electric/optical/mechanical characteristics of wiring pattern

The electrical characteristics of the circuit pattern portion constituted by the mesh network structure of aluminum having a line width of about 2 μm were measured by a 4-terminal resistance measurement method. As a result, it was confirmed that the sheet showed conductivity and the sheet resistance was about 25. omega./□. Next, the optical characteristics were measured/observed by an ultraviolet-visible spectrophotometer and visual observation. As a result, the wiring pattern formed by the mesh-like metal pattern exhibited a light transmittance of about 60% in a visible light wavelength region of 380nm to 780nm in the mesh-like metal pattern portion. It can be confirmed to be transparent by visual observation. Next, a bending test was performed with a bending radius of 2 mm. Even when 100 times of bending was performed, no change was observed in sheet resistance, and high conductivity was maintained.

"comparative example 1" (bending resistance of ITO film)

< Electrical/optical/mechanical Properties of ITO transparent conductive film >

The electrical characteristics of an ITO transparent conductive film (thickness of ITO film is about 75nm) formed on a PET film were measured by a 4-terminal resistance measuring method. As a result, the sheet resistance was about 100. omega./□. At this time, the conductivity was not anisotropic. Next, the optical characteristics were measured/observed by an ultraviolet-visible spectrophotometer and visual observation. As a result, the film exhibited a light transmittance of about 78% in a wavelength region 550nm of visible light, and was visually confirmed to be transparent. Next, a bending test was performed with a bending radius of 2 mm. At the time of 1-time bending, the sheet resistance increased to about 4k Ω/□, and a large decrease in conductivity was observed.