JP2013168575A - Elastic circuit board - Google Patents

Abstract

A circuit board having an organic thin film transistor element, having excellent curved surface followability, can be attached to a human body or a member having a curved surface, and even if attached to such a human body or a member having a curved surface, Provided is a circuit board capable of preventing breakage of an organic thin film transistor element and falling off from a substrate.
A stretchable circuit board according to the present invention includes a substrate, a parylene thin film layer having a thickness of 1 to 1.2 μm formed on the substrate, and a plurality of organic thin film transistor elements formed on the parylene thin film layer. An elastic circuit board having a stretchable conductor connecting the plurality of organic thin film transistor elements, wherein the board contains a (meth) acryloyl group-terminated urethane polymer and an acrylic monomer. The stretchable base material made of the cured product is formed with a partially stretched part made of a specific polymer material partially and integrally, and the plurality of organic thin film transistor elements are placed on the difficultly stretched part of the substrate Has been.
[Selection] Figure 1

Description

  The present invention relates to a stretchable circuit board. More particularly, the present invention relates to a stretchable circuit board having an organic thin film transistor element.

  A thin film transistor (TFT) is used as a switching element for controlling the display operation of each pixel and a driving element for driving each pixel in a flat panel display device such as a liquid crystal display. In addition, since a plastic substrate is used, an organic thin film transistor (OTFT) using an organic semiconductor thin film layer that can be manufactured under a low temperature condition is being developed as a semiconductor thin film layer used for an operation layer of the thin film transistor.

  In Patent Document 1, as a method of manufacturing an organic thin film transistor, a step of forming a gate electrode on a substrate, a step of forming a gate insulating film covering the surface of the gate electrode on the substrate, A step of forming an organic semiconductor film, and a step of forming a source electrode and a drain electrode on the organic semiconductor film, wherein the organic semiconductor film is formed by vacuum evaporation in the organic semiconductor film forming step. In the step of forming the source electrode and the drain electrode, the metal nanoparticle dispersion liquid is applied in a predetermined pattern shape using an ultrafine inkjet printing apparatus to form a metal nanoparticle dispersion liquid coating layer, and the metal nanoparticles An organic thin film transistor characterized by forming a source electrode and a drain electrode composed of a sintered body layer of metal nanoparticles by heating and baking the dispersion coating layer. Method for producing a register is disclosed. Further, in this document, when a thin film layer of an organic semiconductor is formed on a gate insulating film, a “self-assembled monolayer (Self Assembled Monolayer: SAM) "is preferably used. This document also describes that a substrate formed of a plastic material such as polyethylene terephthalate, polyethylene naphthalate, or polyimide can be used as the substrate.

JP 2009-224714 A

  However, when a substrate formed of a material such as polyethylene terephthalate or polyimide is used as the substrate, since the substrate is not stretchable, a circuit substrate having an organic thin film transistor element can be attached to a human body or a member having a curved surface. Have difficulty. On the other hand, when a substrate made of a stretchable material is used as the substrate, although it follows a curved surface, a stress acts on the organic thin film transistor element, and the element may be damaged or fall off from the substrate.

  Accordingly, an object of the present invention is a circuit board having an organic thin film transistor element, which has excellent curved surface followability, can be attached to a human body or a member having a curved surface, and has such a human body or curved surface. An object of the present invention is to provide a circuit board that can prevent the organic thin film transistor element from being damaged or coming off from the board even if it is attached to the board.

  As a result of intensive studies to achieve the above object, the present inventors have found that in a circuit board having an organic thin film transistor element, when a sheet-like stretchable organic base material having a specific structure is used as a board, a member having a human body or a curved surface is used. In addition, the present inventors have found that a circuit board capable of preventing damage to the organic thin film transistor element and falling off from the substrate can be obtained even when attached to such a human body or a member having a curved surface. .

  That is, the present invention relates to a substrate, a parylene thin film layer having a thickness of 1 to 1.2 μm formed on the substrate, a plurality of organic thin film transistor elements formed on the parylene thin film layer, and the plurality of organic thin film transistor elements. A stretchable circuit board having a stretchable conductor connecting between the stretchable circuit boards, the board being stretchable made of a cured product of an energy ray curable composition containing a (meth) acryloyl group-terminated urethane polymer and an acrylic monomer The surface shape or stretchable organic base material surface is made of a polymer material containing an acrylic polymer containing 50% by weight or more of a structural unit derived from a polyfunctional acrylic monomer with respect to all structural units of the polymer Is a sheet-like stretchable organic base material in which a difficult-to-extend portion having a substantially circular projection shape when formed as a projection surface is partially and integrally formed The parylene thin film layer is formed on the surface on the hardly elongated portion side, and the organic thin film transistor element is a p-type semiconductor dinaphtho [2,3-b: 2 ′, 3′-f] thieno [3]. , 2-b] bottom gate top contact type 2V driving thin film transistor (TFT) using thiophene (DNTT), and the stretchable conductor is a carbon nanotube rubber composition comprising single-walled carbon nanotube, rubber and ionic liquid A stretchable circuit board, wherein the stretchable conductive wire is formed of an object, and the plurality of organic thin film transistor elements are placed on the difficultly stretched portion of the substrate via the parylene thin film layer. provide.

  In the vicinity of the interface between the difficultly stretched portion of the sheet-like stretchable organic base material and the stretchable base material, it is preferable that the stretch properties have gradation.

  According to the stretchable circuit board of the present invention, as a substrate, a sheet-like stretchable organic base material in which a stretchable portion having a specific structure is partially and integrally formed in a stretchable base material made of a specific composition. Therefore, the sheet-like stretchable organic substrate can be attached to a human body or a member having a curved surface, and can be attached to a member having a human body or a curved surface. Since the organic thin film transistor element is placed on the difficultly stretched portion of the material, the organic thin film transistor element is not stressed, and the element can be prevented from being damaged or detached from the substrate.

It is a schematic sectional drawing which shows typically the organic thin-film transistor element mounting part which shows an example of the elastic circuit board of this invention. It is a figure (plan view) showing typically an example of the elastic circuit board of the present invention. It is a schematic perspective view which shows an example of the sheet-like stretchable organic base material used as a board | substrate in this invention. It is a schematic perspective view which shows the IV-IV line cross section of the sheet-like stretchable organic base material of FIG. It is the schematic (sectional drawing) which shows an example of the manufacturing method of the sheet-like stretchable organic base material used as a board | substrate in this invention. It is the schematic (plan view) which shows the example of the test sample used with the tension test and hysteresis test of the sheet-like stretchable organic base material used as a board | substrate in this invention. The photograph of the difficulty extension part boundary vicinity in the elastic | stretch base material of the sheet-like elastic organic base material obtained in manufacture example 3 is shown. 4 is a graph showing transistor characteristics when the stretchable circuit board of Example 1 is stretched. 4 is a graph showing transistor characteristics after stretching of the stretchable circuit board of Example 1.

  The stretchable circuit board of the present invention includes a substrate, a parylene thin film layer formed on the substrate, a plurality of organic thin film transistor elements formed on the parylene thin film layer, and a stretchability for connecting the plurality of organic thin film transistor elements. And a conductor.

  FIG. 1 is a schematic sectional view schematically showing an organic thin film transistor element mounting portion showing an example of the stretchable circuit board of the present invention. In this example, a parylene thin film layer 4 is formed on a substrate 1, and an organic thin film transistor element 10 is mounted on the parylene thin film layer 4. The organic thin film transistor element 10 includes a gate electrode 5 in contact with the parylene thin film layer 4, a gate insulating film 6 covering the surface of the gate electrode 5, and a self-assembled monolayer 7 formed on the gate insulating film 6. And an organic semiconductor film 8 formed on the self-assembled monomolecular film 7, and a source electrode 9 a and a drain electrode 9 b formed on the organic semiconductor film 8.

  FIG. 2 is a diagram (plan view) schematically showing an example of the stretchable circuit board of the present invention. In this example, 1 is a substrate, 4 is a parylene thin film layer, 10 is an organic thin film transistor element, and 11 is a stretchable conductor connecting a plurality of organic thin film transistor elements 10.

[substrate]
The substrate is composed of a structural unit derived from a polyfunctional acrylic monomer in a stretchable base material made of a cured product of an energy ray-curable composition containing a (meth) acryloyl group-terminated urethane polymer and an acrylic monomer. A hard-to-extend part which is made of a polymer material containing an acrylic polymer containing 50% by weight or more with respect to all of the structural units, and whose projection shape is substantially circular when the surface shape or the stretchable organic substrate surface is the projection surface It is a sheet-like stretchable organic substrate formed partially and integrally.

  FIG. 3 is a schematic perspective view showing an example of a sheet-like stretchable organic base material used as a substrate in the present invention. 4 is a schematic perspective view showing a cross section taken along line IV-IV of the sheet-like stretchable organic substrate of FIG. 3 and 4, the sheet-like stretchable organic substrate 1 is formed partially and integrally with a stretchable base material 2 (stretchable base material portion) and the stretchable base material 2. It is comprised with the difficult expansion | extension part 3. FIG.

  It is only necessary that a plurality of difficultly stretchable portions 3 are formed partially and integrally in the stretchable base material 2. For example, the stretchable portions 3 are discontinuously scattered or scattered in a plurality of locations in the stretchable base material 2. . The projection shape (the shape seen from the surface side of the stretchable organic substrate 1) when the surface shape of the difficultly stretchable portion 3 or the surface of the stretchable organic substrate 1 is used as the projection surface is substantially circular. The difficultly extending portion 3 is preferably a columnar shape extending in the sheet thickness direction.

  Although the length (for example, diameter) of the long axis (longest part) of the surface direction of the difficult extension part 3 can be suitably selected according to the magnitude | size of an organic thin-film transistor element, it is 0.1-10 mm normally, Preferably 0.5-5 mm. When this length is too small, the mountability and fixing property of the organic thin film transistor element 10 are deteriorated, and when it is too large, it is difficult to manufacture.

  In the vicinity of the interface (boundary part) between the hardly stretchable part 3 and the stretchable base material part 2, a gradation (gradient) in which the composition and / or physical properties (elongation characteristics, hardness, etc.) gradually change may be formed. The stretchable organic base material having such a gradation (for example, a gradation about the elongation rate described later) in the vicinity of the interface between the hardly stretchable part 3 and the stretchable base material part 2 is obtained by, for example, stretching the stretchable organic base material. At this time, it has a characteristic that it is difficult to cut at the interface between the difficultly stretchable portion 3 and the stretchable base material portion 2. Further, gradation is exhibited not only in the vicinity of the interface (boundary portion) between the difficultly stretchable part 3 and the stretchable base material part 2 but also in many or all of the difficult stretchable part 3 and / or the stretchable base material part 2. May be. In the stretchable organic base material having a gradation portion, the boundary between the difficultly stretchable portion 3 and the stretchable base material portion 2 is the hardness of the non-gradient portion of the stretchable base material portion 2 [over the entire stretchable base material portion. When the gradation is exhibited, the hardness of the lowest hardness portion and the hardness of the non-gradient portion of the difficult extension portion 3 [when the gradation is exhibited over the entire difficult extension portion 3, the hardness is the highest. It can be determined by a line connecting the average value of the hardness of the high part].

  In the present invention, the difficultly stretchable portion 3 may be formed in any part of the stretchable base material 2, but is formed in a state where it is exposed on at least one surface in terms of the fixing property of the organic thin film transistor element 10. It is preferable. The difficult extension part 3 may be formed in the state which is not exposed to the surface of an extensible organic base material. Moreover, in order to ensure smooth stretchability of the extensible organic base material, it is preferable that the difficultly stretchable portion 3 is formed at a place other than the end portion in the surface direction of the extensible base material 2. That is, it is preferable that the difficultly stretchable portion 3 is formed in a state of being included in the stretchable base material 2 (excluding both surfaces). However, when the end portion in the surface direction of the stretchable base material 2 is reinforced, or when different properties are imparted to the end portion, the hardly stretchable portion 3 may be formed at the end portion.

  The plurality of difficultly elongated portions 3 formed in the stretchable base material 2 may be formed randomly, but are preferably formed in a regular pattern from the viewpoint of usability. In the case where the plurality of difficultly elongated portions 3 are formed in a regular pattern, the distance (shortest distance) between adjacent difficultly elongated portions 3 is, for example, 0.1 to 10 mm, preferably 0.5 to 5 mm. is there.

  The thickness of the sheet-like stretchable organic substrate 1 is, for example, 50 μm or more, and preferably 100 μm or more. The upper limit of the thickness of the sheet-like stretchable organic substrate 1 is, for example, 1000 μm, and preferably 500 μm.

  The difficultly stretchable portion 3 may be formed continuously from one surface of the sheet-like stretchable organic base material 1, and continues from one surface of the sheet-like stretchable organic base material 1 to the other surface. May be formed. Further, the difficultly stretched portion 3 may be formed by being buried in the sheet-like stretchable organic base material 1. In any case, the length (thickness) in the thickness direction of the difficultly stretchable portion 3 is preferably at least 1/50 of the thickness of the sheet-like stretchable organic substrate 1, more preferably from the viewpoint of usefulness. It is at least 1/20, more preferably at least 1/10, particularly preferably at least 1/4. In addition, from the viewpoint of retention of the organic thin film transistor element 10, for example, when the hardly stretchable portion 3 is continuously formed from one surface of the sheet-like stretchable organic base material 1, the hardly stretchable portion is used. The length (thickness) in the thickness direction of 3 is preferably at least 1/3 of the thickness of the sheet-like stretchable organic base material 1, more preferably at least 1/2 (especially at least 2/3).

  In the present invention, the elongation (breaking elongation) of the sheet-like stretchable organic substrate 1 in the tensile test (test piece width 20 mm, distance between chucks 50 mm, temperature 25 ° C., tensile speed 200 mm / min) is preferably 50. % Or more, more preferably 70% or more, further preferably 120% or more, and the strength (breaking stress) is preferably 1.0 MPa or more, more preferably 2.0 MPa or more, and further preferably 3.0 MPa or more. . The higher the strength, the better, but the upper limit is, for example, 100 MPa, and usually 50 MPa or less. An example of a test sample of the sheet-like stretchable organic substrate 1 used for a tensile test using a tensile tester is shown in FIG.

In the sheet-like stretchable organic base material, the stretchable base material 2 is excellent in stretchability and stretchability, but the difficult stretch portion 3 has low stretchability. When the stretchable organic substrate is stretched to 1.5 times (150% of the original length) in an elongation test (temperature: 25 ° C.) using a tensile tester. (However, for an organic base material that does not extend up to 1.5 times, when it is extended up to 1.25 times), the extension rate S ₁ (%) of the difficult extension part 3 (of the extended length relative to the original length) The ratio is preferably 49% or less, more preferably 40% or less, still more preferably 25% or less, and particularly preferably 10% or less.

The sheet-like stretchable organic base material is 1.5 times (150% of the original length) of the sheet-like stretchable organic base material in an extension test (temperature 25 ° C.) using a tensile tester. When stretched (however, when the organic base material does not stretch up to 1.5 times, when stretched up to 1.25 times), the stretch rate S ₂ (%) of the stretchable base material part 2 (original length) It is preferable that the ratio [S ₂ (%) / S ₁ (%)] of the elongation ratio to the elongation ratio S ₁ (%) of the difficult extension part 3 is larger than 1. In such a sheet-like stretchable organic base material, when the base material is stretched in one direction, even if the stretchable base material portion 2 is stretched, the difficult stretch portion 3 is difficult to stretch and the shape is difficult to change. Therefore, the organic thin film transistor element 10 can be stably fixed and held on the difficult extension portion 3. The ratio [S ₂ (%) / S ₁ (%)] is more preferably 2 or more, and further preferably 5 or more (particularly 10 or more).

Furthermore, the sheet-like stretchable organic base material is 1.5 times (150% of the original length) of the sheet-like stretchable organic base material in an elongation test (temperature 25 ° C.) using a tensile tester. When stretched (however, when the organic base material does not stretch up to 1.5 times, when stretched up to 1.25 times), the stretch rate S ₂ (%) of the stretchable base material part 2 and the difficult stretch part 3 The difference [S ₂ (%) − S ₁ (%)] in the elongation rate S ₁ (%) of the resin is preferably 20% or more, and more preferably 40% or more.

In the present invention, the extensibility of the sheet-like stretchable organic base material is preferably isotropic. For example, the stretch rate S ₂ (1) (%) of the stretchable base material part 2 in one direction and the stretch rate S ₂ (2) (2) of the stretchable base material part 2 in a direction orthogonal to the direction %) [S ₂ (1) / S ₂ (2)] [where S ₂ (1) ≧ S ₂ (2)] is preferably 1 to 1.3, preferably 1 to 1.2. Is more preferable, and 1 to 1.1 is particularly preferable.

  In the present invention, the sheet-like stretchable organic base material has stretchability. In the sheet-like stretchable organic substrate, elongation recovery obtained by a hysteresis test at 50% elongation using a tensile tester (test piece width 20 mm, distance between chucks 50 mm, temperature 25 ° C., tensile speed 200 mm / min) The rate is preferably 10% or more, more preferably 30% or more, still more preferably 50% or more (particularly preferably 70% or more).

Moreover, in the said sheet-like stretchable organic base material, the stretchable base material 2 is usually soft, and the difficult extension part 3 is hard. For example, in the sheet-like stretchable organic base material, a hardness test using a rubber hardness tester (10 pieces of a stretchable organic base material having a test piece of 30 mm × 30 mm, hardness after 10 seconds of needle pressing, temperature is preferably greater than the ratio of the hardness _{H 1} of the flame extension portion 3 and the hardness of _{H 2} stretchable base material _{2 (H} 1 / H 2) is 1 as determined by 25 ° C.), more preferably 1.01 More preferably, it is 1.10 or more, and particularly preferably 1.20 or more.

Moreover, a tensile elasticity modulus can also be used as a scale of the hardness of the stretchable base material 2 and the difficultly stretchable portion 3. In the sheet-like stretchable organic substrate, a solid viscoelasticity measuring device (sample size: length 25 mm × width 3 mm, distance between chucks: 5 mm, mode: time dispersion, temperature: 27 ° C., frequency: 1 Hz, initial strain: 0.2%, measurement time: 120 sec, number of measurements: 10 times) the tensile modulus of the flame extension portion 3 as measured by E _'1 (Pa) and a tensile modulus E of the elastic base material 2' ₂ (Pa) The ratio (E ′ ₁ / E ′ ₂ ) is preferably greater than 1, more preferably 5 or more, still more preferably 10 or more, and particularly preferably 100 or more.

Furthermore, the load in the nanoindentation measurement can also be used as a measure of the hardness of the stretchable base material 2 and the hardly stretchable part 3. The stretch in the organic substrate, the nano-indentation measurements the load P ₁ of the flame extension portion 3 in (indentation depth 4 [mu] m, indentation rate 1.5 [mu] m / sec, the temperature 25 ° C.) stretchable base material 2 of the load P ₂ The ratio (P ₁ / P ₂ ) is preferably greater than 1, more preferably 1.01 or more, still more preferably 1.10 or more, and particularly preferably 1.50 or more.

  In addition, the surface roughness Ra of the surface (at least one surface) of the stretchable base material portion 2 and the surface (at least one surface) of the formation site of the hardly stretchable portion 3 is preferably 100 nm or less, more preferably 50 nm or less. Preferably, it is 30 nm or less. In particular, the smaller the surface roughness of the difficult extension portion 3, the more accurately the organic thin film transistor element can be installed, and the performance of the organic thin film transistor element can be surely exhibited. Ra can be measured by an AFM (atomic force microscope).

[Elastic base material]
In the present invention, the stretchable base material 2 is composed of a cured product of an active energy ray-curable composition containing a (meth) acryloyl group-terminated urethane polymer and an acrylic monomer.

  The (meth) acryloyl group-terminated urethane polymer can be produced by a known method, for example, by reacting a urethane polymer having an isocyanate group at a terminal with hydroxylalkyl (meth) acrylate.

  The urethane polymer having an isocyanate group at the terminal is obtained by reacting a polyisocyanate compound, a long-chain polyol compound, and a chain extender or other isocyanate-reactive compound used as necessary by a conventional method. be able to.

  Examples of the polyisocyanate compound include aliphatic diisocyanates such as hexamethylene diisocyanate and trimethylhexamethylene diisocyanate; alicyclic diisocyanates such as isophorone diisocyanate, dicyclohexylmethane diisocyanate, hydrogenated xylylene diisocyanate, norbornene diisocyanate, and norbornane diisocyanate; naphthalene diisocyanate, Aromatic diisocyanates, such as phenylene diisocyanate, tolylene diisocyanate, diphenyl diisocyanate, diphenylmethane diisocyanate, diphenyl ether diisocyanate, diphenylpropane diisocyanate; xylylene diisocyanate, tetramethylene xylylene diisocyanate, etc. ; And dimer acid diisocyanate.

  Examples of the long-chain polyol compound include polyether polyol, polyester polyol, polycarbonate polyol, polyolefin polyol, and polyacryl polyol. The number average molecular weight of the long-chain polyol is usually 500 or more, preferably 500 to 10000, more preferably 550 to 4000. Long chain polyols can be used alone or in combination of two or more.

  Examples of the polyether polyol include polyalkylene ether glycols such as polyethylene ether glycol, polypropylene ether glycol, polytetramethylene ether glycol (PTMG), and a plurality of alkylene oxides as monomer components such as an ethylene oxide-propylene oxide copolymer. (Alkylene oxide-other alkylene oxide) copolymer containing etc. are mentioned.

  Examples of the polyester polyol include a condensation polymer of a polyhydric alcohol and a polyvalent carboxylic acid; a ring-opening polymer of a cyclic ester (lactone); a reaction by three kinds of components: a polyhydric alcohol, a polyvalent carboxylic acid, and a cyclic ester. Things can be used. In the condensation polymerization product of polyhydric alcohol and polycarboxylic acid, examples of polyhydric alcohol include ethylene glycol, diethylene glycol, propylene glycol, 1,3-propanediol, 1,4-butanediol, 2-methyl-1 , 3-propanediol, 1,5-pentanediol, neopentyl glycol, 1,6-hexanediol, 1,9-nonanediol, 1,10-decanediol, glycerin, trimethylolpropane, trimethylolethane, cyclohexanediol (Such as 1,4-cyclohexanediol), cyclohexanedimethanols (such as 1,4-cyclohexanedimethanol), bisphenols (such as bisphenol A), sugar alcohols (such as xylitol and sorbitol), etc. Kill. On the other hand, examples of the polyvalent carboxylic acid include aliphatic dicarboxylic acids such as malonic acid, maleic acid, succinic acid, adipic acid, suberic acid, azelaic acid, sebacic acid, and dodecanedioic acid; 1,4-cyclohexanedicarboxylic acid, etc. And aromatic dicarboxylic acids such as terephthalic acid, isophthalic acid, orthophthalic acid, 2,6-naphthalenedicarboxylic acid and trimellitic acid. In the ring-opening polymer of cyclic ester, examples of the cyclic ester include propiolactone, β-methyl-δ-valerolactone, and ε-caprolactone. In the reaction product of the three types of components, those exemplified above can be used as the polyhydric alcohol, polycarboxylic acid, and cyclic ester.

  Examples of the polycarbonate polyol include a reaction product of a polyhydric alcohol and phosgene, chloroformate, dialkyl carbonate or diaryl carbonate; a ring-opening polymer of a cyclic carbonate (such as alkylene carbonate). Specifically, in the reaction product of polyhydric alcohol and phosgene, the polyhydric alcohol includes the polyhydric alcohols exemplified above (for example, ethylene glycol, propylene glycol, 1,3-butanediol, 1,4-butanediol). , Neopentyl glycol, 1,6-hexanediol, etc.) can be used. In the ring-opening polymer of cyclic carbonate, examples of the alkylene carbonate include ethylene carbonate, trimethylene carbonate, tetramethylene carbonate, hexamethylene carbonate, and the like. In addition, the polycarbonate polyol should just be a compound which has a carbonate bond in a molecule | numerator, and the terminal is a hydroxyl group, and may have an ester bond with a carbonate bond. Representative examples of polycarbonate polyols include polyhexamethylene carbonate diol, diol obtained by ring-opening addition polymerization of lactone to polyhexamethylene carbonate diol, and cocondensate of polyhexamethylene carbonate diol with polyester diol or polyether diol. Etc.

  The polyolefin polyol is a polyol having an olefin as a component of the skeleton (or main chain) of the polymer or copolymer and having at least two hydroxyl groups in the molecule (particularly at the terminal). The olefin may be an olefin having a carbon-carbon double bond at the terminal (for example, an α-olefin such as ethylene or propylene), or an olefin having a carbon-carbon double bond at a position other than the terminal. (For example, isobutene and the like) and diene (for example, butadiene, isoprene and the like) may be used. Typical examples of polyolefin polyols include butadiene homopolymers, isoprene homopolymers, butadiene-styrene copolymers, butadiene-isoprene copolymers, butadiene-isoprene copolymers such as butadiene-modified polymers modified with hydroxyl groups at the ends. .

The polyacrylic polyol is a polyol having (meth) acrylate as a component of the polymer (or copolymer) skeleton (or main chain) and having at least two hydroxyl groups in the molecule (particularly at the terminal). As the (meth) acrylate, (meth) acrylic acid alkyl ester [for example, (meth) acrylic acid C _1-20 alkyl ester, etc.] is preferably used.

  As the chain extender, a chain extender usually used in the production of thermoplastic polyurethane can be used, and the kind thereof is not particularly limited, but a low molecular weight polyol, polyamine or the like can be used. The molecular weight of the chain extender is usually less than 500, preferably 300 or less. A chain extender can be used individually or in combination of 2 or more types.

  Representative examples of chain extenders include, for example, ethylene glycol, propylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, neopentyl glycol, 1,6-hexanediol, Polyols (especially diols) such as 1,4-cyclohexanediol and 1,4-cyclohexanedimethanol; hexamethylenediamine, 3,3'-dimethyl-4,4'-diaminodicyclohexylmethane, 4,4'-methylenebis- Examples include polyamines such as 2-chloroaniline (particularly diamines).

  The urethane polymer having an isocyanate group at the terminal includes a polyisocyanate compound, a long-chain polyol compound, and optionally a chain extender and other isocyanate-reactive compounds, and the number of moles of isocyanate groups of the polyisocyanate. It is obtained by reacting within a range where the ratio (NCO / isocyanate reactive group) to the number of moles of isocyanate reactive groups (hydroxyl group, amino group, etc.) of the long-chain polyol and chain extender is 1 or more. In this reaction, in order to accelerate the reaction, a catalyst such as a tertiary amine, an organometallic compound, or a tin compound may be used as necessary.

  As said hydroxyalkyl (meth) acrylate, hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, hydroxybutyl (meth) acrylate etc. can be used, for example. These hydroxyalkyl (meth) acrylates can be used singly or in combination of two or more.

  The reaction between the urethane polymer having an isocyanate group at the terminal and hydroxylalkyl (meth) acrylate can be performed by a known or conventional method.

In the present invention, as the acrylic monomer, for example, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, isopropyl (meth) acrylate, n-butyl (meth) acrylate, Isobutyl (meth) acrylate, s-butyl (meth) acrylate, t-butyl (meth) acrylate, pentyl (meth) acrylate, isopentyl (meth) acrylate, hexyl (meth) acrylate, (meth) acryl Heptyl acid, octyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, isooctyl (meth) acrylate, nonyl (meth) acrylate, isononyl (meth) acrylate, decyl (meth) acrylate, (meth) Isodecyl acrylate, undecyl (meth) acrylate, dodecy (meth) acrylate , Tridecyl (meth) acrylate, tetradecyl (meth) acrylate, pentadecyl (meth) acrylate, hexadecyl (meth) acrylate, heptadecyl (meth) acrylate, octadecyl (meth) acrylate, nonadecyl (meth) acrylate, (Meth) acrylic acid C _1-20 alkyl ester such as (meth) acrylic acid eicosyl; having an alicyclic group such as (meth) acrylic acid cyclopentyl, (meth) acrylic acid cyclohexyl, (meth) acrylic acid isobornyl (meta) ) Acrylic acid ester; (meth) acrylic acid ester having an aromatic hydrocarbon group such as phenyl (meth) acrylate, benzyl (meth) acrylate, phenoxyethyl (meth) acrylate; methoxyethyl (meth) acrylate, (Meth) Ethoxyethyl acrylate, etc. (Meth) acrylic acid alkoxyalkyl; (meth) acrylic acid 2-hydroxyethyl, (meth) acrylic acid 2-hydroxypropyl, (meth) acrylic acid 3-hydroxypropyl, (meth) acrylic acid 4-hydroxybutyl, Hydroxyl group-containing monomers such as 6-hydroxyhexyl (meth) acrylate; (meth) acrylic acid, 2-carboxyethyl (meth) acrylate, 2- (meth) acryloyloxyethyl succinic acid, 2- (meth) acryloyl Examples thereof include carboxyl group or acid anhydride group-containing monomers such as oxyethyl phthalic acid; epoxy group-containing monomers such as glycidyl (meth) acrylate and methyl glycidyl (meth) acrylate.

  As the acrylic monomer, in addition to the above, 1,6-hexanediol di (meth) acrylate, 1,4-butanediol di (meth) acrylate, (poly) ethylene glycol di (meth) acrylate, (poly) propylene Glycol di (meth) acrylate, neopentyl glycol di (meth) acrylate, pentaerythritol di (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol hexa (meth) acrylate, tri Methylolpropane tri (meth) acrylate, tetramethylolmethane tri (meth) acrylate, trimethylolpropane EO-added tri (meth) acrylate, glycerin PO-added tri (meth) acrylate , Can be used allyl (meth) acrylate, vinyl (meth) acrylate, divinylbenzene, epoxy acrylate, polyester acrylate, a polyfunctional monomer such as urethane acrylate. “EO” represents ethylene oxide, and “PO” represents propylene oxide.

In the present invention, it is preferable to use at least (meth) acrylic acid C _1-20 alkyl ester as the acrylic monomer. In order to improve the adhesion strength at the interface between the stretchable base material 2 and the hardly stretchable portion 3, it is also preferable to use at least the same monomer as the polymer monomer constituting the difficult stretch portion 3 as the acrylic monomer.

When (meth) acrylic acid C _1-20 alkyl ester (meth) acrylic acid C _1-20 alkyl ester is used as the acrylic monomer, (meth) acrylic acid C _1-20 alkyl ester occupying the entire acrylic monomer. The ratio is, for example, 10% by weight or more (10 to 100% by weight), preferably 40% by weight or more (40 to 100% by weight), more preferably 50% by weight or more (50 to 100% by weight), and still more preferably 60%. % By weight (60 to 100% by weight). In addition, (meth) acrylic acid C _1-20 alkyl ester as the acrylic monomer, (meth) acrylic acid ester having an alicyclic group such as isobornyl (meth) acrylate, carboxyl group such as (meth) acrylic acid Alternatively, an acid anhydride group-containing monomer or a hydroxyl group-containing monomer such as 2-hydroxyethyl (meth) acrylate may be used. In this case, the amount of (meth) acrylic acid ester having a cycloaliphatic group such as isobornyl (meth) acrylate, a carboxyl group or acid anhydride group-containing monomer, and a hydroxyl group-containing monomer is used with respect to the entire curable monomer. , For example, can be selected from the range of 0 to 90% by weight (about 0.1 to 90% by weight), preferably 0 to 50% by weight (about 0.1 to 50% by weight), and 1 to 45% by weight. About% may be used.

  The ratio of the (meth) acryloyl group-terminated urethane polymer and the acrylic monomer [the former / the latter (weight ratio)] is, for example, 1/99 to 99/1, preferably 20/80 to 95/5, more preferably. Is 25/75 to 90/10, more preferably 30/70 to 75/25. When this ratio is too small, extensibility and stretchability tend to be lowered.

  The proportion (total amount) of the (meth) acryloyl group-terminated urethane polymer and the acrylic monomer in the active energy ray-curable composition is, for example, 50% by weight or more, preferably 80% by weight or more, more preferably 90% by weight. % Or more.

  The stretchable base material 2 can be formed by irradiating the active energy ray-curable composition with an energy ray such as ultraviolet rays and curing it. At this time, a photopolymerization initiator is usually used. Examples of photopolymerization initiators include benzoin ether photopolymerization initiators, acetophenone photopolymerization initiators, α-ketol photopolymerization initiators, aromatic sulfonyl chloride photopolymerization initiators, and photoactive oxime photopolymerization initiators. Benzoin photopolymerization initiators, benzyl photopolymerization initiators, benzophenone photopolymerization initiators, ketal photopolymerization initiators, thioxanthone photopolymerization initiators, and the like are used.

  Examples of the benzoin ether photopolymerization initiator include benzoin methyl ether, benzoin ethyl ether, benzoin propyl ether, benzoin isopropyl ether, benzoin isobutyl ether, 2,2-dimethoxy-1,2-diphenylethane-1-one, Anisole methyl ether etc. are mentioned. Examples of the acetophenone photopolymerization initiator include 2,2-diethoxyacetophenone, 2,2-dimethoxy-2-phenylacetophenone, 1-hydroxycyclohexyl phenyl ketone, 4-phenoxydichloroacetophenone, and 4- (t-butyl). ) Dichloroacetophenone and the like. Examples of the α-ketol photopolymerization initiator include 2-methyl-2-hydroxypropiophenone and 1- [4- (2-hydroxyethyl) phenyl] -2-methylpropan-1-one. It is done. Examples of the aromatic sulfonyl chloride photopolymerization initiator include 2-naphthalenesulfonyl chloride. Examples of the photoactive oxime photopolymerization initiator include 1-phenyl-1,1-propanedione-2- (o-ethoxycarbonyl) -oxime. Examples of the benzoin photopolymerization initiator include benzoin. Examples of the benzyl photopolymerization initiator include benzyl. Examples of the benzophenone photopolymerization initiator include benzophenone, benzoylbenzoic acid, 3,3′-dimethyl-4-methoxybenzophenone, polyvinyl benzophenone, α-hydroxycyclohexyl phenyl ketone, and the like. Examples of the ketal photopolymerization initiator include benzyl dimethyl ketal. Examples of the thioxanthone photopolymerization initiator include thioxanthone, 2-chlorothioxanthone, 2-methylthioxanthone, 2,4-dimethylthioxanthone, isopropylthioxanthone, 2,4-diisopropylthioxanthone, dodecylthioxanthone, and the like.

  Although it does not specifically limit as the usage-amount of a photoinitiator, For example, it is 0.01-3 weight part with respect to 100 weight part of total amounts of the curable compound in an active energy ray curable composition, The upper limit is Preferably it is 1 weight part, More preferably, it is 0.5 weight part, The lower limit becomes like this. Preferably it is 0.02 weight part, More preferably, it is 0.05 weight part.

  If necessary, the stretchable base material part 2 may be, for example, a crosslinking agent (for example, an isocyanate crosslinking agent, an epoxy crosslinking agent, a melamine crosslinking agent, a peroxide crosslinking agent, a urea crosslinking agent, a metal alkoxide). Crosslinking agent, metal chelate crosslinking agent, metal salt crosslinking agent, carbodiimide crosslinking agent, oxazoline crosslinking agent, aziridine crosslinking agent, amine crosslinking agent, etc.), crosslinking accelerator, silane coupling agent, tackifying resin (Rosin derivatives, polyterpene resins, petroleum resins, oil-soluble phenols, etc.), anti-aging agents, fillers, colorants (pigments and dyes, etc.), UV absorbers, antioxidants, plasticizers, softeners, surfactants, Additives such as antistatic agents may be included within the range not impairing the properties of the present invention.

[Difficult to stretch]
In the present invention, the difficultly stretched portion 3 has a structural unit derived from a polyfunctional acrylic monomer in an amount of 50% by weight or more (more preferably 60% by weight or more, more preferably 80% by weight or more) with respect to all the structural units of the polymer. It is comprised from the polymer material containing the acrylic polymer to contain. The polymer in the polymer material may be a single type or a mixture of two or more types.

  The proportion of the acrylic polymer containing the structural unit derived from the polyfunctional acrylic monomer in an amount of 50% by weight or more based on the total structural unit of the polymer in the entire polymer material constituting the difficult extension part is, for example, 5% by weight or more, preferably Is 10% by weight or more, more preferably 15% by weight or more, and may be 50% by weight or more (for example, 90% by weight or more).

  Examples of polyfunctional acrylic monomers include 1,6-hexanediol di (meth) acrylate, 1,4-butanediol di (meth) acrylate, (poly) ethylene glycol di (meth) acrylate, and (poly) propylene glycol di (Meth) acrylate, neopentyl glycol di (meth) acrylate, pentaerythritol di (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol hexa (meth) acrylate, trimethylolpropane Such as tri (meth) acrylate, tetramethylolmethane tri (meth) acrylate, trimethylolpropane EO-added tri (meth) acrylate, and glycerin PO-added tri (meth) acrylate. And the like. Among the polyfunctional monomers, those having 3 or more functional groups (for example, 3 to 6 functional groups) are most preferable.

  Acrylic polymer containing difficult-to-extend part 3 with 50% by weight or more (more preferably 60% by weight or more, more preferably 80% by weight or more) of structural units derived from polyfunctional acrylic monomers with respect to all structural units of the polymer For example, the energy ray-curable composition containing the monomer component containing the polyfunctional acrylic monomer in an amount of 50% by weight or more of the whole monomer is formed in the stretchable base material forming material layer. It can be formed by irradiating with energy rays and curing (polymerization) after being disposed on the site. In this case, as a monomer other than the polyfunctional acrylic monomer, a monofunctional monomer can be appropriately selected from the monomers exemplified as the acrylic monomer for forming the stretchable base material.

  When forming the difficult elongation part 3, a photopolymerization initiator is usually used to cure the curable group. It does not specifically limit as a photoinitiator, The photoinitiator similar to the case where the said elastic base material 2 is formed can be used. Although it does not specifically limit as the usage-amount of a photoinitiator, It is 0.01-3 weight part with respect to 100 weight part of sclerosing | hardenable compound whole quantity, The upper limit becomes like this. Preferably it is 1 weight part, More preferably The lower limit is preferably 0.02 parts by weight, more preferably 0.05 parts by weight.

  In the difficult extension part 3, for example, a crosslinking agent (for example, an isocyanate crosslinking agent, an epoxy crosslinking agent, a melamine crosslinking agent, a peroxide crosslinking agent, a urea crosslinking agent, a metal alkoxide crosslinking agent) is used. Agents, metal chelate crosslinking agents, metal salt crosslinking agents, carbodiimide crosslinking agents, oxazoline crosslinking agents, aziridine crosslinking agents, amine crosslinking agents), crosslinking accelerators, silane coupling agents, tackifying resins (rosin) Derivatives, polyterpene resins, petroleum resins, oil-soluble phenols, etc.), anti-aging agents, fillers, colorants (pigments, dyes, etc.), UV absorbers, antioxidants, plasticizers, softeners, surfactants, antistatic agents Additives such as an agent may be included as long as the characteristics of the present invention are not impaired.

[Production of sheet-like stretchable organic substrate]
The sheet-like stretchable organic base material in the present invention can be produced, for example, through the following step A, step B and step C.

Step A: Step of forming a stretchable base material forming material layer on a support using an energy ray-curable composition containing the (meth) acryloyl group-terminated urethane polymer and an acrylic monomer Step B: The energy beam-curable composition for forming the difficultly stretched portion is disposed at a predetermined portion of the stretchable base material forming material layer so that the surface shape of the difficultly stretched portion or the projected surface shape of the base material has a desired shape. Step C: Energy ray curing for forming the difficultly stretched portion by irradiating the stretchable base material forming material layer provided with the energy beam curable composition for forming the difficultly stretchable portion. The process of obtaining the sheet-like stretchable organic base material in which the difficultly stretched part is partially and integrally formed in the stretchable base material by curing the stretchable composition and the stretchable base material forming material layer. Schematic illustration showing the above method (cross-sectional view) It is. In FIG. 5, (a) is step A, (b) is step B, (c), (d), (e), (f) [or (d '), (e'), (f)] It corresponds to process C.

  In step A, the stretchable base material forming material layer 20 is formed on the support 40. Although it does not specifically limit as the support body 40, For example, a separator can be used. The separator is not particularly limited, and a conventional release paper, a separator having a release treatment layer, a low adhesive substrate made of a fluoropolymer, a low adhesive substrate made of a nonpolar polymer, and the like can be used. Examples of the separator having the release treatment layer include a plastic film or paper surface-treated with a release treatment agent such as silicone-based, long-chain alkyl-based, fluorine-based, or molybdenum sulfide. Examples of the fluorine-based polymer in the low adhesion substrate made of the above-mentioned fluoropolymer include polytetrafluoroethylene, polychlorotrifluoroethylene, polyvinyl fluoride, polyvinylidene fluoride, tetrafluoroethylene-hexafluoropropylene copolymer, chloro Examples include fluoroethylene-vinylidene fluoride copolymer. Moreover, as said nonpolar polymer, olefin resin (for example, polyethylene, a polypropylene, etc.) etc. are mentioned, for example. The separator can be manufactured by a known or conventional method. Further, the thickness of the separator is not particularly limited.

  The stretchable base material forming material layer 20 has an energy ray curable composition (including a photopolymerization initiator) 30 containing the (meth) acryloyl group-terminated urethane polymer and an acrylic monomer on a support 40. It can be formed by coating.

  A solvent may be added to the energy beam curable composition as necessary, but it is preferable not to use a solvent because a process for removing the solvent later increases. Moreover, in order to prevent superposition | polymerization by a heat | fever, you may add a polymerization inhibitor to the said energy beam curable composition as needed.

  The energy beam curable composition is preferably in the form of a syrup. The viscosity of the energy beam curable composition is, for example, 0.1 to 50 Pa at a coating temperature (for example, a predetermined temperature within a range of 10 to 40 ° C., particularly 25 ° C.) from the viewpoint of workability and the like. S, the upper limit is preferably 30 Pa · s, more preferably 20 Pa · s, and the lower limit is preferably 0.5 Pa · s, more preferably 1 Pa · s. If the viscosity is too low, the shape tends to be difficult to maintain. Conversely, if the viscosity is too high, the coating workability tends to decrease.

  The coating method of the energy beam curable composition is not particularly limited, and for example, a coater such as a Mayer bar, a blade coater, an air knife coater, a roll coater, a die coater, an extruder, a printing machine, or the like can be used. The stretchable base material forming material layer 20 can also be formed using an appropriate mold. In this case, the viscosity of the energy beam curable composition may be lower than the above range.

  The thickness of the stretchable base material forming material layer 20 is, for example, 10 to 2000 μm, the upper limit is preferably 1000 μm, more preferably 500 μm, and the lower limit is preferably 50 μm, more preferably 100 μm. .

  In step B, the energy beam curable composition for forming the hardly stretchable portion is formed so that the surface shape of the difficultly stretched portion or the projected surface shape of the base material has a desired shape at a predetermined portion of the stretchable base material forming material layer. Dispose (include) the product 30.

  Step B is an energy beam curable composition containing a monomer component containing 50% by weight or more (more preferably 60% by weight or more, more preferably 80% by weight or more) of a polyfunctional acrylic monomer, and a photopolymerization initiator. Is added (dropped) from above to a predetermined portion of the stretchable base material forming material layer 20.

  It is preferable that the energy beam curable composition 30 for forming a difficultly stretched portion has a syrup shape. From the viewpoint of workability and the like, the viscosity of the energy beam curable composition 30 for forming a difficult elongation part is, for example, a temperature at the time of coating (for example, a predetermined temperature within a range of 10 to 40 ° C., particularly 25 ° C.). The upper limit is preferably 30000 mPa · s, more preferably 20000 mPa · s, and the lower limit is preferably 20 mPa · s, more preferably 30 mPa · s. If the viscosity is too low, it is difficult to obtain a desired shape. Conversely, if the viscosity is too high, the coating workability tends to be lowered.

  The addition and injection method of the energy beam curable composition 30 for forming a difficult-to-extend part is not particularly limited, and for example, a syringe, an appropriate dropping device, or the like can be used.

  By adjusting the amount of use and the viscosity of the energy beam curable composition 30 for forming a hardly stretchable part, the size (size and height in the surface direction) of the difficultly stretched part 3 after curing can be controlled. In the case of forming a plurality of the hardly stretchable polymer portions 3, the energy ray curable composition 30 for forming the hardly stretchable portion is applied at an appropriate interval. In addition, the shape of the hard extension part 3 after hardening is controllable by using the means which regulates the addition or injection | pouring location of the energy beam curable composition 30 for hard extension part formation.

  After application (coating, dripping, printing) of the energy ray-curable composition for forming difficult stretchable parts to the stretchable base material forming material layer, the hard stretchable part forming material is stretchable base material as necessary. It is left until it penetrates and shifts to a predetermined depth of the forming material layer.

  In step C, the stretchable base material-forming material layer 20 provided with the hardly stretchable part forming energy beam curable composition 30 is irradiated with energy rays to form the difficultly stretchable part energy beam curable composition 30. Then, the stretchable base material forming material layer 20 is cured to obtain a sheet-like stretchable organic base material in which the stretchable portions 3 are partially and integrally formed in the stretchable base material 2.

  Although ultraviolet rays (UV) are used as energy rays in FIG. 5, ionizing radiation such as α rays, β rays, γ rays, neutron rays, electron rays, and visible rays may be used.

  The irradiation energy, irradiation time, irradiation method, and the like of the energy beam are not particularly limited as long as the photopolymerization initiator can be activated to cause the monomer component to react.

  As the energy beam irradiation device, a conventional device can be used. For example, when irradiating ultraviolet rays, a mercury lamp, a fluorescent lamp, a sodium lamp, a metal halide lamp, a xenon lamp, a neon tube, a neon lamp, a high-intensity discharge lamp, or the like can be used.

  A stretchable base material forming material layer containing the energy beam curable composition 30 for forming a hardly stretchable part for the purpose of preventing curing inhibition by oxygen and the purpose of smoothing the surface during irradiation with energy rays. The cover film 50 may be laminated on the surface of 20. As the cover film 50, a separator similar to the support 40 can be used. Lamination | stacking of the cover film 50 can be performed using a hand roller etc., for example.

Energy beam irradiation may be performed in several stages. For example, in the case of irradiating ultraviolet rays, as shown in FIG. 5C, irradiation is performed for a short time (for example, an integrated irradiation amount of 10 to 1000 mJ / cm ² ) at a high illuminance (for example, 50 to 1000 mW / cm ² ). Then, as shown in FIG. 5 (d), the cover film 50 is laminated, and after that, as shown in FIG. 5 (e), it is long at a low illuminance (for example, 1 to 40 mW / cm ² ). You may perform time irradiation (for example, integrated irradiation amount 500-10000mJ / cm < ² >). Thus, the workability at the time of lamination | stacking of the cover film 50 by a hand roller can be improved by dividing energy beam irradiation in several steps. In the figure, 200 is a partially cured stretchable base material forming material layer, and 300 is a partially cured energy beam curable composition for forming a difficultly stretched portion.

In the case where the energy beam irradiation is performed in a single stage, for example, after step B, as shown in FIG. 5 (d ′), the stretchability containing the energy beam curable composition 30 for forming a hardly stretchable portion is contained. A cover film 50 may be laminated on the surface of the base material forming material layer 20 and irradiated with ultraviolet rays as shown in FIG. Illuminance of ultraviolet in this case, for example 1~40mW / cm ^2, integrated dose is, for example, 500~10000mJ / cm ^2.

  After curing the energy beam curable composition 30 for forming a difficultly stretched portion and the stretchable base material forming material layer 20 as described above, as shown in FIG. The film 50 and the support 40 are peeled off and cut to an appropriate size as necessary, and used as the sheet-like stretchable organic substrate 1. The cutting operation may be performed before the cover film 50 or the support 40 is peeled off.

  In addition, the sheet-like stretchable organic base material having gradation regarding the composition and / or physical properties (elongation characteristics, hardness, etc.) in the vicinity of the interface between the difficultly stretched portion and the stretchable base material portion is formed by, for example, stretchable base material. It can be manufactured by using materials that are common or similar to each other (monomers, etc.) or materials that are compatible with each other (solvents, monomers, etc.). Such gradation is formed by diffusion and migration of monomer components, solvents, and the like, and subsequent curing, solvent removal, and the like. Therefore, the gradation part of the extensible organic base material having the gradation is different from the composition assumed from the material for forming each part (difficult to stretch part, stretchable base material part). The gradation level (width) can be adjusted by the type and amount of the stretchable base material forming material and the difficult stretch portion forming material (monomer or the like). In addition, as described above, when a polymer is blended in the energy ray curable composition as the material for forming a difficultly stretched portion, the degree of gradation (width) is determined depending on the type, amount, weight average molecular weight, and the like of the polymer. It can also be adjusted.

  The sheet-like stretchable organic substrate thus obtained is used as a substrate in the stretchable circuit board of the present invention.

[Parylene thin film layer]
In this invention, it has the parylene thin film layer 4 on the surface at the side of the difficult extension part 3 of the board | substrate 1. FIG. By providing the parylene thin film layer 4, the heat resistance of the surface on which the organic thin film transistor element 10 is placed is improved, the hardness of the surface of the substrate 1 is increased, and damage such as bending of the base material due to process heat can be reduced. The thin film transistor element 10 can be stably placed on the difficult extension 3 of the substrate 1. Further, by providing the parylene thin film layer 4 on the substrate 1, the substrate 1 and the device used in the elastic circuit board manufacturing process and its components are adhered to each other by the tack of the surface of the elastic base material 2 of the substrate 1. The above trouble can be prevented.

  Parylene is a general term for paraxylylene-based polymers, and includes Parylene N, Parylene C, Parylene D, Parylene HT, Parylene diX-SR, and the like. In the present invention, any of these parylenes can be used, among which parylene diX-SR having high heat resistance is preferable.

  The parylene thin film layer 4 is not particularly limited, but can be formed, for example, by depositing parylene on the surface of the substrate 1 by a known vapor deposition method (for example, a vacuum vapor deposition method, a thermal CVD method, or the like).

  The parylene thin film layer 4 has a thickness of 1 to 1.2 μm. If the thickness of the parylene thin film layer 4 is less than 1 μm, it cannot be said that the heat resistance of the difficultly stretched portion for mounting the organic thin film transistor element 10 is sufficient, and a metal mask used for patterning at the time of gate electrode film formation by the vacuum evaporation method is stuck. End up. On the other hand, when the thickness of the parylene thin film layer 4 exceeds 1.2 μm, the stretchability of the sheet-like stretchable organic base material that is the substrate tends to be impaired, and the flatness of the surface of the difficultly stretchable portion 3 is impaired.

[Organic thin film transistor element]
In the present invention, the organic thin film transistor element is a bottom gate top contact type 2V using p-type semiconductor dinaphtho [2,3-b: 2 ′, 3′-f] thieno [3,2-b] thiophene (DNTT). A driving thin film transistor (TFT) is used.

  The organic thin film transistor element 10 shown in FIG. 1 is an example thereof (see, for example, JP 2009-224714 A).

  In FIG. 1, the organic thin film transistor element 10 is formed on the gate insulating film 6 as described above, the gate electrode 5 in contact with the parylene thin film layer 4, the gate insulating film 6 covering the surface of the gate electrode 5. A self-assembled monolayer film 7, an organic semiconductor film 8 formed on the self-assembled monolayer film 7, and a source electrode 9 a and a drain electrode 9 b formed on the organic semiconductor film 8. Has been.

In the organic thin-film transistor element 10, for example, the size of the gate electrode 5, the gate length: _{L G} is in the range of 5 m to 30 m, preferably, selected in the range of 7Myuemu～20myuemu, gate width: _{W G} is 100 m to 300 m Select the range. The channel _{length: L channel,} the gate length: based on the _{L G,} the range of _{2L G ≧ L channel ≧ L G} , preferably, selected within the range of _{4/3 · L G ≧ L} channel ≧ L G. That is, it is formed so as to sandwich the gate electrode 5. The source electrode 9a and the drain electrode 9b spacing between the side edge of the gate electrode side: LS-D has a gate length: based on the _{L G,} the range of _{2L G ≧ L S-D ≧} L G, preferably, 4 / 3 · _{L G} ≧ _L selected from the range of _S-D ≧ _{L G.}

The gate electrode 5 is located below the gate insulating film 6 and the source electrode 9a and the drain electrode 9b are located above the gate insulating film 6, but when viewed from directly above, the shape of the source electrode 9a and the drain electrode 9b is substantially each short side of length L _S, rectangle having long sides of length W _S, the short side length L _D, be regarded as a rectangle having a long side length W _D can, the shape of the gate insulating film 6, as can be regarded as rectangular having short sides, the long side length W _G of the length L _G, to select a pattern of the electrodes preferable.

Usually, the gate electrode 5, when selecting the shape of the source electrode 9a and the drain electrode 9b as described above, to one side of the rectangular pattern of the source electrode 9a and the drain electrode 9b, five rectangular pattern of the gate electrode length W _G Arrange so that the long sides are parallel. For example, the long side length W _S of the rectangular pattern of the source electrode 9a and the drain electrode 9b, the long side length W _D is located such that a long side length W _G of the rectangular pattern of the gate electrode is parallel To do. At that time, the long side length W _S of the rectangular pattern of the source electrode 9a and the drain electrode 9b, the long side length W _D is shorter than the long side length W _G of the rectangular pattern of the gate electrode 5, also , it selects the long side of the long side and the length W _D of the length W _S equal length. That _is, selected to satisfy the condition of _{W G> W S = W D} . For _example, the condition of _{W G> W S = W D} ≧ 1/2 · W G, _preferably selected so as to satisfy the condition _{W G> W S = W D} ≧ 2/3 · W G. For example, the long side length _{W S} of the rectangular pattern of the source electrode 9a and the drain electrode 9b, the long side length _{W D,} satisfy the condition of _{W G> W S = W D} ≧ 2/3 · W G to The range is selected from the range of 70 μm to 250 μm.

On the other hand, an organic semiconductor thin film layer (organic semiconductor film) 8 used as an operation layer of the organic thin film transistor element 10 has at least a channel region of channel length: L _channel , substantially a short side of length L _channel , Patterning is performed so that it can be regarded as a rectangle having a long side of length W _channel . The width of the channel region: W _channel is made smaller than the gate width of the gate electrode 5: WG. Usually, the width of the channel _{region: W channel} is preferably smaller than the long sides of the long sides, the length _{W D} of the length _{W S} of the rectangular pattern of the source electrode 9a and the drain electrode 9b. That is, at least the condition of W _G > W _channel is satisfied, and preferably, the condition of W _G > W _S = W _D ≧ W _channel is satisfied. For _example, the condition of _{W G> W S = W D} ≧ W channel ≧ 1/2 · W G, more _preferably, satisfies the conditions of _{W G> W S = W D} ≧ W channel ≧ 2/3 · W G To choose. For example, the width of the channel _region: a _{W channel,} the _{W G>} W S = W condition _{D ≧ W channel ≧ 2/3} · W G in full to the range, to select the range of 70Myuemu～250myuemu.

In the organic thin film transistor, the length of the channel region: L _channel corresponds to the distance between the side edges of the source electrode 9a and the drain electrode 9b on the gate electrode 5 side: L _SD . When viewed from directly above the channel region, and a side edge of the gate electrode 5 side source electrode 9a, the gap between the side edge of the gate electrode 5: and [Delta] L _S-G, and the side edge of the gate electrode 5 side drain electrode 9b The sum of the gap with the side edge of the gate electrode 5: ΔL _D−G is (L _S−D −L _G ) = (ΔL _S−G + ΔL _D−G ). Therefore, L _G ≧ (ΔL _S−G + ΔL _D−G ) ≧ 0, preferably 1/3 · L _G ≧ (ΔL _S−G + ΔL _D−G ) ≧ 0. For example, gate length: _{L G} is in the range of 5 m to 30 m, preferably, when it is selected in the range of _{7μm~20μm, (ΔL S-G +} ΔL D-G) is in the range of 0Myuemu～20myuemu, preferably, A range of 0 μm to 10 μm is selected.

When forming a rectangular pattern of the source electrode 9a and the drain electrode 9b, the pattern drawing accuracy needs to be higher than the value of (ΔL _S−G + ΔL _D−G ). In other words, the pattern drawing accuracy is preferably selected so that the minimum space width is in the range of 1 μm to 10 μm. Further, it is preferable to maintain the pattern drawing accuracy so that the line width variation (fluctuation width from the straight line) to be drawn is in the range of 1 μm to 10 μm. When drawing using an ultra-fine inkjet printer, droplet diameter is applied so that the dot diameter (diameter) to which each droplet is applied is in the range of 0.5 μm to 5 μm, depending on the drawing accuracy. Set conditions.

  As a metal for forming the gate electrode 5, a metal species conventionally used for forming the gate electrode 5 of the organic thin film transistor element can be used. In the present invention, it is preferable to employ a metal selected from Au, Ag, Cu, Al, Cr, Ni, and Ti as the metal that forms the gate electrode 5. Among these, Al is preferable. When forming the gate electrode 5 on the parylene thin film layer 4, a technique of forming a metal thin film by using a vapor deposition method or a sputtering method and applying a photolithographic method to pattern the desired shape pattern can be used. . Also in the formation process of the gate electrode 5, the metal nanoparticle dispersion liquid is applied in a predetermined pattern shape using an ultrafine ink jet printing apparatus to form a metal nanoparticle dispersion liquid coating layer on the substrate, and the metal The gate electrode 5 made of a sintered body layer of metal nanoparticles can also be formed by heating and baking the nanoparticle dispersion coating layer.

As an insulating material for forming the gate insulating film 6, an insulating material conventionally used for forming a gate insulating film of an organic thin film transistor element can be used. In the present invention, as the insulating material for forming the gate insulating film 6, inorganic insulating materials such as SiO ₂ , SiN, AlOx (aluminum oxide; Al ₂ O _3, etc.) and Ta ₂ O ₅ can be suitably used. Among these, AlOx is preferable. The gate insulating film 6 made of these inorganic insulating materials is formed by using a PE-CVD (Plasma-Enhanced Chemical Vapor Phase Deposition) method or a sputtering method to form an insulating film having a desired film thickness, and using a photolithography method. A method of applying and patterning a desired shape pattern can be used. The film thickness of the gate insulating film 6 is selected in a range in which a desired gate breakdown voltage can be achieved in consideration of the relative dielectric constant: ε _{r-I of the} insulating film to be used and the insulation resistance.

  The thickness of the gate electrode: Tgate is usually preferably selected to be smaller than the film thickness: Tinsulator of the gate insulating film 6 covering the surface. That is, the selection is made so as to satisfy the condition of Tinsulator ≧ Tgate. For example, the thickness of the gate electrode: Tgate is set so as to satisfy the condition of 3/4 · Tinsulator ≧ Tgate ≧ 1/8 · Tinsulator, preferably 2/3 · Tinsulator ≧ Tgate ≧ 1/6 · Tinsulator. select.

  As long as the above conditions are satisfied, since the gate insulating film thickness: Tinsulator is thicker than the step (Tgate) due to the side edge of the gate electrode, the gate insulating film is also formed on the side wall surface of the step portion. The coating by is reliably achieved.

Alternatively, in the present invention, as the insulating material for forming the gate insulating film 6, an organic insulating material, for example, an insulating resin material such as an epoxy resin can be used. Even when an insulating resin material is used, the film thickness of the gate insulating film 6 is within a range in which a desired gate breakdown voltage can be achieved in consideration of the relative dielectric constant: ε _{r-I of the} insulating film to be used and the insulation resistance. select.

An organic semiconductor thin film layer formed on the gate insulating film 6 is used as an operation layer. At that time, in the channel region, an effective channel layer is formed immediately above the gate electrode at the interface between the gate insulating film 6 and the organic semiconductor film 8. That is, when the gate voltage: V _G applied to the gate electrode exceeds the threshold bias: V _th (V _G <V _th ), the drain current passing through the effective channel layer: I _d-ON Flows into the “ON state”.

  Also in the present invention, when the organic semiconductor thin film layer (organic semiconductor film) 8 is formed on the gate insulating film 6, the “self-assembled monolayer (Self Assembled Monolayer) of the organic compound is previously formed on the surface of the gate insulating film 6. : SAM) "7 is preferably used. Regarding this method, for example, US Pat. No. 6,433,359 (Patent Document 1), Frank-J. Meyer zu Heringdorf, et al. “Growth Dynamics of Pentacene Thin Films”, Nature Vol. 412 517 (2001) discloses the details.

  Examples of the method for forming the self-assembled monomolecular film 7 of the organic compound constituting the organic semiconductor film 8 include an immersion method and a stamp method.

  In the dipping method, the surface on which the self-assembled monomolecular film 7 is formed is subjected to an ashing treatment (for example, 300 W for 5 minutes), and then immersed in a monomolecular dispersion in which the organic compound is dispersed in a single molecule. Thereby, a monomolecular film grows in a “self-organizing” lateral direction with the monomolecule adsorbed on the surface of the gate insulating film 6 as a nucleus, and finally, a self-assembled monomolecular film having a regular molecular orientation. 7 is formed.

  In the stamp method, a support such as polydimethylsiloxane is heated and dried, and then immersed in a monomolecular dispersion and dried to form a self-assembled monolayer 7 on the surface of the support, thereby obtaining a stamp. Thereafter, the surface of the gate insulating film 6 is subjected to an ashing process (for example, at 300 W for 5 minutes), the self-assembled monolayer 7 is adhered, and then the self-assembled monolayer 7 is peeled off from the support. The organized monolayer 7 is transferred. According to this stamp method, swelling of the sheet-like stretchable organic base material can be prevented.

For example, when a “self-assembled monomolecular film” is formed using n-octadecylphosphonic acid (C ₁₈ H ₃₇ PO ₃ H), an n-octadecyl phosphonic acid is formed on the base insulating film formed on the surface of the gate electrode. - it is preferable that the fixing of the octadecyl phosphonic acid _{(C 18 H 37 PO 3 H} ) is made. Specifically, it is preferable that fixation is performed through an ester bond between the hydroxy group (—OH) present on the surface of the base insulating film and the phosphonic acid. As a base insulating film used for this purpose, a film made of a metal oxide that can be formed by oxidizing a metal constituting a gate electrode, such as aluminum oxide, silver oxide, or tantalum oxide, is adopted. Is preferred.

  Thereafter, when the organic compound is deposited using the self-assembled monomolecular film 7 as an underlayer using a vacuum evaporation method, the deposited layer also has an organic structure that maintains the ordered arrangement reflecting the regularity of the underlayer. A semiconductor thin film layer (organic semiconductor film) 8 is formed.

  The organic semiconductor thin film layer (organic semiconductor film) 8 using the self-assembled monomolecular film 7 as an underlayer can be evaporated because the deposition process on the underlayer uses a vacuum evaporation method. It can be applied to low molecular organic semiconductor materials. For example, acenes such as tetracene and pentacene, oligothiophene derivatives, phthalocyanines, dinaphtho [2,3-b: 2 ′, 3′-f] thieno [3,2-b] thiophene (dinaphthothiofetaphene, DNTT The organic semiconductor thin film layer 8 can be suitably used. When the organic semiconductor layer to be produced is a layer made of pentacene, which is a typical p-type organic semiconductor, or hexadecafluorocopper phthalocyanine, which is a typical n-type organic semiconductor, this is a particularly effective means. Also in the present invention, the organic semiconductor layer to be formed is made of pentacene or hexadecafluoro copper phthalocyanine and dinaphtho [2,3-b: 2 ', 3'-f] thieno [3,2-b] thiophene (DNTT). A layer is preferred.

Usually, it is preferable to select the film thickness T _channel of the organic semiconductor film 8 in the range of 30 nm to 100 nm.

For example, when an organic semiconductor film formed of pentacene, which is a p-type organic semiconductor material, is employed, the thickness of the organic semiconductor film: T _channel is preferably selected in the range of 30 nm to 50 nm. When an organic semiconductor film formed of hexadecafluorocopper phthalocyanine, which is an n-type organic semiconductor material, is employed, the thickness of the organic semiconductor film: T _channel should be selected in the range of 30 nm to 50 nm. preferable. Further, when an organic semiconductor film formed of dinaphtho [2,3-b: 2 ′, 3′-f] thieno [3,2-b] thiophene (DNTT) is employed, the film of the organic semiconductor film Thickness: T _channel is preferably selected in the range of 30 nm to 50 nm.

  After forming the organic semiconductor film 8 on the gate insulating film 6, the source electrode 9 a and the drain electrode 9 b are formed on the surface of the organic semiconductor film 8. As a method for forming the source electrode 9a and the drain electrode 9b, a metal nanoparticle dispersion liquid is applied in a predetermined pattern shape using a known method, for example, an ultrafine inkjet printing apparatus, and a metal nanoparticle dispersion liquid coating is performed. A method of forming a source electrode 9a and a drain electrode 9b made of a sintered body layer of metal nanoparticles by forming a layer and subjecting the metal nanoparticle dispersion liquid coating layer to heat baking treatment can be adopted (Japanese Patent Application Laid-Open No. 2009-224714). No. publication).

  In the said method, the minimum line | wire width of the said metal nanoparticle dispersion liquid coating layer can be selected in the range of 1 micrometer-10 micrometers, and the coating film thickness of a metal nanoparticle dispersion liquid coating layer can be selected in the range of 30 nm-600 nm. Moreover, the average particle diameter of the metal nanoparticle currently disperse | distributed in the said metal nanoparticle dispersion liquid can be made into the range of 1-100 nm.

  The metal nanoparticles may be selected from the group consisting of metals consisting of gold, silver, copper, platinum, palladium, nickel, tantalum, bismuth, indium, tin, titanium, and aluminum. Examples thereof include a mixture of nanoparticles composed of two or more kinds of metals, or nanoparticles composed of an alloy of two or more kinds of metals selected from the group of the metals. Among these, gold is particularly preferable.

  In the stretchable circuit board of the present invention, a plurality of organic thin film transistor elements 10 are mounted on the difficultly stretched portion 3 of the substrate 1 (via the parylene thin film layer 4). In the stretchable circuit board of the present invention, even if the sheet-like stretchable organic base material 1 is stretched, the hardly stretchable portion 3 hardly stretches and the deformation is very small. Further, the organic thin film transistor element 10 can be prevented from being damaged or dropped off.

[Elastic conductor]
In the stretchable circuit board of the present invention, the plurality of organic thin film transistor elements 10 mounted on the upper portion of the difficult extension portion 3 are connected by the stretchable conductor 11.

  The stretchable conductor 11 includes a word line 11a connected to the gate electrode and a bit line 11b connected to the drain electrode 9b. The overlapping portion between the word line 11a and the bit line 11b is electrically insulated by a known method.

  This stretchable conductor 11 is formed of a carbon nanotube rubber composition comprising carbon nanotubes, rubber and ionic liquid. As this carbon nanotube rubber composition, a well-known thing, for example, the carbon nanotube rubber composition described in the international 2009/102077 pamphlet can be used.

  The carbon nanotube is not particularly limited, and various known carbon nanotubes can be used. Preferable carbon nanotubes include powder-like single-walled carbon nanotubes in which an aligned aggregate of carbon nanotubes grown vertically aligned from a substrate is peeled off from the growth substrate. The length of the carbon nanotube is, for example, 1 μm or more and 10 cm or less.

  The ionic liquid preferably has a high affinity for carbon nanotubes and becomes a gel when dispersed. Examples of ionic liquids include 1-ethyl-3-methylimidazolium tetrafluoroborate, 1-ethyl-3-methylimidazolium hexafluorophosphate, 1-ethyl-3-methylimidazolium bis (trifluoromethylsulfonyl) imide 1-butyl-3-methylimidazolium tetrafluoroborate, 1-butyl-3-methylimidazolium hexafluorophosphate, 1-butyl-3-methylimidazolium bis (trifluoromethylsulfonyl) imide and the like.

  The rubber is not particularly limited, and natural rubber and synthetic rubber can be used. For example, fluorine rubber, natural rubber, propylene rubber, butadiene rubber, isoprene rubber, styrene butadiene rubber, chloroprene acrylo rubber, nitrile butadiene rubber, butyl rubber. Ethylene propylene rubber, urethane rubber, silicone rubber, chlorostyrenated polyethylene rubber, chlorinated polyethylene rubber, acrylic rubber, epichlorohydrin rubber, polysulfide rubber and the like. Among these, fluororubber and silicone rubber are preferable from the viewpoints of handleability and elasticity.

  The carbon nanotube rubber composition is obtained, for example, by adding carbon nanotubes and an ionic liquid to an organic solvent, stirring and mixing to obtain a carbon nanotube ionic liquid gel, adding rubber thereto, and stirring and mixing. Can do. Examples of the organic solvent include toluene, xylene, acetone, carbon tetrachloride, 4-methyl-2-pentanone, and the like.

  Carbon nanotubes and ionic liquids have high affinity, and the carbon nanotubes are gelled by dispersing the carbon nanotubes in the ionic liquid. When a rubber miscible with the ionic liquid is added and mixed in the carbon nanotube ionic liquid gel, the rubber is uniformly dispersed in the carbon nanotube ionic liquid gel.

  In the carbon nanotube rubber composition, the amount of the ionic liquid is, for example, 50 to 1000 parts by weight with respect to 100 parts by weight of the carbon nanotubes, the lower limit is preferably 100 parts by weight, and the upper limit is preferably 500 parts. Parts by weight. The amount of the rubber is, for example, 100 to 10,000 parts by weight with respect to 100 parts by weight of the carbon nanotubes, the lower limit is preferably 150 parts by weight, and the upper limit is preferably 7000 parts by weight.

  The stretchable conductor 11 is formed by printing the carbon nanotube rubber composition in a predetermined pattern on the parylene thin film layer on the substrate 1 (so that the organic thin film transistor elements are connected) by screen printing, die cutting printing, It can be formed by printing, applying and drying using inkjet printing, a dispenser or the like.

  Thereby, an elastic circuit board can be obtained.

When such a stretchable circuit board is stretched 145% in the plane direction (uniaxial direction), the electrical characteristics of the transistor do not change, and when it is stretched 20% in the plane direction (uniaxial direction). The carrier mobility of the organic thin film transistor element is, for example, 0.1 to 1.0 cm ² / Vs.

  Note that the carrier mobility is an amount indicating the ease of movement of electrons in a solid substance, and is one of the parameters that determine the electrical characteristics of the substance. The mobility is inversely proportional to the resistance value, and in the case of a semiconductor, carriers are electrons and holes, and are defined as values indicating the ease of carrier movement.

  The carrier mobility can be measured with a semiconductor parameter analyzer.

  If the carrier mobility is in the above range, good contact between the semiconductor and the insulating film is realized, and the reciprocal hysteresis of the transfer curve that affects the input / output characteristics of the transistor is small, so that the carrier stays stationary. Can be suppressed.

  In the stretchable circuit board of the present invention, the plurality of organic thin film transistor elements 10 are connected by the stretchable conductor 11 and are electrically connected. Since the stretchable base material 1 and the stretchable conductor 11 are both stretchable, the stretchable circuit board of the present invention has excellent curved surface followability and can be attached to a human body or a member having a curved surface. And as mentioned above, even if the sheet-like stretchable organic base material 1 is stretched, the hardly stretchable portion 3 hardly stretches, so that the organic thin film transistor element 10 placed and fixed on the difficult stretchable portion 3 is damaged. , Can prevent falling out.

  Therefore, the stretchable circuit board of the present invention can be used in ambient electronics, for example, electronic devices that are interactive with humans, or electrical devices that are used in human bodies for health care.

  EXAMPLES Hereinafter, although an Example and a comparative example are given and this invention is demonstrated more concretely, this invention is not limited at all by these.

Production Example 1 (Manufacture of base material syrup)
In a reaction vessel equipped with a condenser, a thermometer, and a stirrer, 71 parts by weight of isobornyl acrylate (trade name “IBXA”, manufactured by Osaka Organic Chemical Industry Co., Ltd.) as a (meth) acrylic monomer, n -Poly (oxytetramethylene) glycol having a number average molecular weight of 650 using 19 parts by weight of butyl acrylate (BA, manufactured by Toa Gosei Co., Ltd.), 10 parts by weight of acrylic acid (AA, manufactured by Toa Gosei Co., Ltd.), and polyol. (PTMG650, manufactured by Mitsubishi Chemical Co., Ltd.) 68.4 parts by weight and 0.01 part by weight of dibutyltin dilaurate (DBTL) as a catalyst were added, and while stirring, hydrogenated xylylene diisocyanate (HXDI, Mitsui Chemicals Polyurethane ( 25.5 parts by weight) was added dropwise and reacted at 65 ° C. for 5 hours to obtain a urethane polymer-acrylic monomer mixture. Thereafter, 6.1 parts by weight of hydroxyethyl acrylate (trade name “Acrix HEA”, manufactured by Toa Gosei Co., Ltd.) was further added and reacted at 65 ° C. for 1 hour, whereby an acryloyl group-terminated urethane polymer-acrylic monomer mixture. Got. Thereafter, 0.15 parts by weight of 2,2-dimethoxy-1,2-diphenylethane-1-one (trade name “Irgacure 651”, manufactured by BASF) was added as a photopolymerization initiator. The isocyanate group-containing component and polyol (hydroxyl group-containing component) had an NCO / OH (functional group equivalent ratio) of 1.25 and a polymer concentration of 50 wt%. The viscosity (25 ° C.) of the obtained syrup (base material syrup) was 8 Pa · s.

Production Example 2 (Manufacture of Syrup for Forming Difficult Extensions)
100 parts by weight of trimethylolpropane EO-added triacrylate (trade name “Biscoat # 360”, manufactured by Osaka Organic Chemical Industry Co., Ltd.) and blue dye (trade name “SZ7620”, manufactured by Dainichi Seika Kogyo Co., Ltd.) 1 part by weight and 2,2-dimethoxy-1,2-diphenylethane-1-one (trade name “Irgacure 651” 0.1 parts by weight as a photoinitiator were added and dispersed, and an acrylic monomer mixture (difficult A syrup for forming an extensible polymer part (hardly stretchable part) was obtained, and the viscosity (25 ° C.) of the syrup for forming a difficultly stretched part was 66 mPa · s.

Production Example 3 (Production of sheet-like stretchable organic base material)
The base material syrup obtained in Production Example 1 was applied to the surface of a separator (trade name “MRF38”, manufactured by Mitsubishi Plastics Co., Ltd., thickness 38 μm) with an applicator to form a base material syrup layer having a thickness of 200 μm. . From above, the difficultly stretched part forming syrup (about 0.01 g) obtained in Production Example 2 is dropped onto a predetermined portion of the base material syrup layer, and the island-shaped difficultly stretched part forming syrup part is elongated in the longitudinal direction. Patterns were formed at 30 mm intervals (center-to-center distance). From above, ultraviolet rays are irradiated by an ultraviolet lamp (black light type) (ultraviolet illuminance: 3.4 mW / cm ² , integrated irradiation amount: 100 mJ / cm ² ), and a base material syrup and a syrup for forming an inextensible polymer part After semi-curing, a cover separator (trade name “MRF38”, manufactured by Mitsubishi Plastics Co., Ltd., thickness 38 μm) is pasted onto the semi-cured syrup with a hand roller, and then UV light is applied with an ultraviolet lamp (black light type). (Ultraviolet light illuminance: 3.4 mW / cm ² , integrated irradiation amount: 2000 mJ / cm ² ), for forming a substantially columnar difficult stretch portion in a cured product of the base material syrup (= easily stretchable polymer base material) Stretchable organic base material in which syrup hardened portions (= hardly stretchable polymer portions) (diameter of about 8 mm) are arranged at a predetermined interval [30 mm spacing (distance between centers)] (Thickness: 200 μm) was obtained.

  FIG. 7 shows a photograph of the vicinity of the hardly stretchable part boundary in the stretchable base material of the obtained sheet-like stretchable organic base material.

Example 1
Parylene diX-SR (manufactured by Daisan Kasei Co., Ltd.) was vapor-deposited by a chemical vapor deposition method on the surface of the stretchable organic substrate A obtained in Production Example 3 on the difficultly stretched portion side, and a parylene thin film having a thickness of 1.1 μm. A layer was formed.

  Next, in the same manner as in Example 1 in Japanese Patent Application Laid-Open No. 2009-224714, a gate electrode and a gate insulating film are formed on the surface of the obtained parylene thin film layer corresponding to the difficultly stretched portion of the stretchable organic base material A. After forming the self-assembled monolayer, an organic semiconductor layer, a source electrode, and a drain electrode were further formed on the surface. Thereby, the organic thin-film transistor element was laminated | stacked on the parylene thin film layer.

That is, in the gate electrode, the shape of the portion of the channel region used for the TFT switching operation is a rectangular shape. In the rectangular shape, the gate length: _{L G} is the 1 [mu] m, the gate width: _{W G} is selected 300 [mu] m. The metal species of the gate electrode was aluminum, and a deposited film having a film thickness: Tgate = 20 nm was patterned into the above-described shape pattern.

Further, a gate insulating film made of self-assembled monolayer (SAM film) / AlO _x was formed so as to cover the gate electrode and cover the entire surface of the substrate 1. At that time, the thickness of the AlO _x layer immediately above the gate electrode: T _AlOx was set to T _AlOx = 200 nm. In the region on the surface of the parylene thin film layer, a self-assembled monomolecular film (SAM film) was formed on the AlO _x film.

  Further, a coating film of the metal nanoparticle dispersion for forming the source electrode and the drain electrode is formed on the gate insulating film at a position sandwiching the gate electrode. The metal nanoparticle dispersion was prepared by forming a coating molecular layer of dodecylamine (melting point: 28.3 ° C., boiling point: 248 ° C.) on the surface of silver nanoparticles having an average particle diameter D: 3 nm. (Tetradecane, viscosity 2.0-2.3 mPa · s (20 ° C.), melting point 5.86 ° C., boiling point 253.57 ° C., manufactured by Nikko Petrochemical Co., Ltd.). The metal nanoparticle dispersion contained 20 parts by mass of the coating molecule dodecylamine and 52 parts by mass of N14 as the dispersion solvent per 100 parts by mass of the silver nanoparticles. In addition, the liquid viscosity of this silver nanoparticle dispersion liquid was 10 mPa * s (20 degreeC).

Using silver nanoparticle dispersion of the bore diameter of the discharge hole of the ultra-fine inkjet device: Select D _open to 0.2 [mu] m, and set the droplet volume to be injected into 0.7FL, to form a coating film . Assuming that a droplet having a droplet volume VO of 0.7 fL at the time of ejection has a spherical shape, the droplet diameter: D ₀ (diameter) corresponds to 1 μm. Under these coating conditions, the average diameter of dots drawn with one droplet of 0.7 fL of droplet volume at the time of ejection was 1 to 2 μm.

The shape of the metal nanoparticle dispersion liquid coating film for forming the source electrode is a rectangle with a short side: L _S = 2 μm and a long side: W _S = 300 μm, and the thickness of the coating film: T _S-draw is 0.3 μm. Selected. The space between the long side of the rectangular pattern of the coating film and the side edge on the source electrode side of the gate electrode: ΔL _S−G was selected to be ΔL _S−G = 1 μm.

The shape of the coating film of the metal nanoparticle dispersion liquid for forming the drain electrode 5 is a rectangle having a short side: L _D = 2 μm and a long side: W _D = 300 μm, and the thickness of the coating film: T _D-draw is 0. 3 μm was selected. The space between the long side of the rectangular pattern of the coating film and the side edge of the gate electrode on the drain electrode side: ΔL _D−G was selected to be ΔL _D−G = 1 μm.

  The metal nanoparticle dispersion coating film was subjected to a low-temperature firing treatment in a nitrogen gas stream at a temperature of 130 ° C. for 60 minutes to form a sintered body layer of silver nanoparticles.

Separately, in a sintered body layer of rectangular silver nanoparticles having a width of 2 μm and a length of 100 μm, which is produced under the same conditions on a SAM film used as a gate insulating film, the average film thickness of the sintered body layer: When T _baked was measured, it was 0.3 μm. The resistivity of the silver nanoparticle sintered body layer was 25 μΩ · cm.

The sintered body layer of silver nanoparticles obtained by low-temperature firing treatment was used as a source electrode and a drain electrode. Accordingly, the film thicknesses T _S and T _D of the source electrode and the drain electrode are estimated to be 0.3 μm on average. Further, the line width disturbance (micro unevenness): δL _S , δL _D at each side of the rectangular pattern of the silver nanoparticle sintered body layer was estimated to be 100 nm.

The distance between the produced source electrode and drain electrode: L _SD was 2 μm. The length of the design value of the channel _region: For _{L channel} = 3 [mu] m, the difference _{(L channel} -L _S-D) was slightly 1 [mu] m.

Formation of the gate insulating film made of self-assembled monomolecular film (SAM film) / AlO _x was performed by the following steps. That is, first, plasma oxidation treatment was performed on the surface of the Al gate electrode, and an AlO _x layer was formed on the Al surface. Thereafter, when a water washing treatment was performed, Al—OH type hydroxy groups were present at a high density on the surface of the AlO _x layer. Thereafter, it was immersed in a monomolecular dispersion solution to form a monomolecular film in a self-compositional manner on the surface of the AlO _x layer. The monomolecular dispersion solution is obtained by dispersing n-octadecylphosphonic acid (C ₁₈ H ₃₇ PO ₃ H) in a dispersion solvent 2 propanol at a dispersion concentration of 1-5 mmol / L or more. After being immersed in the monomolecular dispersion solution at a liquid temperature of 30 ° C. for 2 hours, it was taken out, and the remaining dispersion liquid was removed by nitrogen blowing treatment, followed by annealing in an oven at 100 ° C. for 10 minutes. n- octadecyl phosphonic acid _{(C 18 H 37 PO 3 H} ) reacts with Al-OH type hydroxy groups of the AlO _x layer surface, result in the formation of an ester bond, SAM to AlO _x layer surface A film was formed.

Pentacene was deposited on the surface of the gate insulating film in which the “self-assembled monolayer” was formed on the surface of the AlO _x layer by an evaporation method. The film thickness of the deposited pentacene vapor deposition film: T _channel is selected to be 30 nm. As the pentacene vapor deposition conditions, a pentacene vapor deposition source temperature of 230 ° C. and a substrate temperature of 60 ° C. are selected. In addition, the film thickness of the deposited pentacene vapor film: T _channel is separately prepared on the SAM film / AlOx laminated film used for the gate insulating film under the same vapor deposition conditions, and the vapor deposition time and vapor deposition film. This is an estimated value based on the result of measuring the correlation of thickness. At that time, the thickness of the pentacene vapor-deposited film can be measured by ellipsometry, assuming that the relative refractive index of the pentacene vapor-deposited film is equal to the relative refractive index of the solid.

Finally, the organic semiconductor layer was patterned into a rectangular shape having a predetermined pattern shape, length: L _OS = 40 μm, and width: W _OS = 300 μm.

  In addition, 400 (40 (longitudinal direction) × 10 (width direction)) organic thin film transistor elements were formed on the parylene thin film layer.

  On the other hand, a carbon nanotube rubber paste (carbon nanotube rubber composition) is prepared in the same manner as in Example 1 in International Publication No. 2009/102077 pamphlet, and the organic thin film transistor elements are connected by printing the paste. It was applied to. Thereafter, the carbon nanotube rubber paste was dried and the organic thin film transistor elements were connected by wiring made of carbon nanotube rubber in the same manner as in Example 1 in the pamphlet of International Publication No. 2009/102077.

That is, as a carbon nanotube, a powder-like shape in which a carbon nanotube alignment aggregate which has been grown vertically aligned from a substrate using the method described in Japanese Patent Application Nos. 2009-001586 and 2006-527894 is peeled off from the growth substrate. Single-walled carbon nanotubes (hereinafter SWNT) were used. The carbon nanotube has a density of 0.03 g / cm ³ , a BET-specific surface area of 1200 m ² / g, an average outer diameter of 2.5 nm, a half width of 2 nm, a carbon purity of 99.9%, a Herman orientation coefficient of 0.8, It has a length of 300 μm or more and 800 μm or less.

  SWNT (typical amount 30 mg) and ionic liquid BMITFSI (typical amount 60 mg) are added to the organic solvent 4-methyl-2-pentanone (typical amount 20 ml), and the mixture is stirred at room temperature under a rotation speed of over 700 rpm using a stirrer. The mixture obtained was stirred in a jet mill disperser (NANO-JET PAL, JN10, JOKOH Co., Ltd.) and jetted at 60 MPa to uniformly disperse the carbon nanotubes in an organic solvent. A liquid gel is obtained.

  Next, this carbon nanotube ionic liquid gel is a fluororubber having a miscibility and compatibility with the organic solvent 4-methyl-2-pentanone (typical amount 80 ml) and the ionic liquid (Daikin Kogyo Daiel-G912) ( A typical amount of 50-1500 mg) is added and stirred with a stirrer at about 300 rpm at room temperature for 16 hours to obtain a carbon nanotube rubber paste.

  This carbon nanotube / rubber dispersion gel is dried at room temperature for 12 hours to obtain a carbon nanotube rubber. The composition of the carbon nanotube rubber was 21 wt% SWNT, 43 wt% BMITFSI, 36 wt% G912, and the conductivity was 73 S / cm.

  Then, the carbon nanotube rubber paste is dried at room temperature for 6 hours, and a part of 4-methyl-2-pentanone is evaporated to adjust the viscosity, then printed between the organic thin film transistor elements, dried, and dried to have a width of 100 μm. A wiring made of carbon nanotube rubber on a PDMS substrate patterned to a line width was obtained.

  Thereby, an elastic circuit board was obtained.

[Evaluation test]
<Measurement of elongation>
Place the sample (20mm width) of the sheet-like extensible organic base material obtained in Example 3 so that two or more hardly extensible polymer parts can be inserted between the chucks (50mm) (between the centers of the two hard polymer parts) Distance: 30 mm), tensile test (temperature: 25 ° C., tensile speed: 200 mm / min) with a tensile tester (trade name “Autograph AG-X 200N”, manufactured by Shimadzu Corporation), 50% elongation The elongation rate S ₁ (%) (average value) in the elongation direction of the hardly extensible polymer portion at the time (150% of the original length) and the site other than the hardly extensible polymer portion [easily extensible polymer base ( = Easy extension part)] is measured in the extension direction S ₂ (%) (average value), and the ratio (S ₂ / S ₁ ) and difference (S ₂ -S ₁ ) (%) are calculated. Asked. When S ₁ = 0, S ₂ / S ₁ = ∞.

The elongation rate S ₁ (%) is determined by measuring the elongation direction diameter of the hardly extensible polymer portion (substantially the diameter of the substrate surface) before and after elongation, and the formula: {(length after elongation−length before elongation) Length) / (length before stretching)} × 100).

Elongation rate S ₂ (%) is marked with 6 marks in the extension direction of the part other than the hardly-extensible polymer part (easily-extensible polymer base material part), and the length between adjacent marks before and after extension. And calculated by the formula: {(length after stretching−length before stretching) / (length before stretching)} × 100).

As a result, S ₁ (%) = 1, S ₂ (%) = 78, (S ₂ / S ₁ ) = 78, and (S ₂ −S ₁ ) (%) = 77.

  In addition, the sheet-like extensible organic base material obtained in Production Example 3 also had stretchability.

<Transistor characteristics during and after extension>
The stretchable circuit board obtained in Example 1 was stretched in the surface direction, and the properties of the transistors provided on the stretchable circuit board were examined in the stretched state.

  That is, the stretchable circuit board was stretched in various directions up to 0 to 145% in the uniaxial direction (1.0 to 2.45 times the original length), and the electrical characteristics of the transistor during stretching were measured. .

  Note that when the elongation ratio exceeded 145%, the electrical characteristics of the transistor could not be measured because the sheet-like extensible organic base material was broken.

  Further, the elongation strain was released, and the electrical characteristics of the stretched transistor were measured.

  The obtained electrical characteristics are shown in FIGS. 8 and 9, respectively.

  As can be seen from FIG. 8 and FIG. 9, even when the elongation ratio was extended to 145%, the electrical characteristics of the transistor showed almost no change and showed excellent characteristics.

<Measurement of carrier mobility>
The stretchable circuit board obtained in Example 1 was stretched by 20% in the plane direction, and the carrier mobility of the organic thin film transistor element was measured using a semiconductor parameter analyzer (part number: 4156C, manufactured by Agilent). And field effect mobility was measured. As a result, the carrier mobility was 0.1 to 1.0 cm ² / Vs.

1 Sheet-like stretchable organic substrate (substrate)
2 Elastic base material (part)
20 Polymer matrix forming material layer (stretchable matrix forming energy beam curable composition layer)
200 Partially cured energy ray curable composition layer for forming stretchable base material 3 Difficult elongation part 30 Difficult elongation part forming material (energy ray curable composition for difficult elongation part formation)
300 Partially cured energy beam curable composition for formation of difficultly stretched portion 4 Parylene thin film layer 5 Gate electrode 6 Gate insulating film 7 Self-assembled monolayer 8 Organic semiconductor film 9a Source electrode 9b Drain electrode 10 Organic thin film transistor element 11 Stretchable Conductor 40 Support 50 Cover film

Claims (2)

A substrate, a parylene thin film layer having a thickness of 1 to 1.2 μm formed on the substrate, a plurality of organic thin film transistor elements formed on the parylene thin film layer, and a stretchability for connecting the plurality of organic thin film transistor elements A stretchable circuit board having a conductor,
The substrate is composed of a structural unit derived from a polyfunctional acrylic monomer in a stretchable base material made of a cured product of an energy ray-curable composition containing a (meth) acryloyl group-terminated urethane polymer and an acrylic monomer. A hard-to-extend part which is made of a polymer material containing an acrylic polymer containing 50% by weight or more with respect to all of the structural units, and whose projection shape is substantially circular when the surface shape or the stretchable organic substrate surface is the projection surface It is a sheet-like stretchable organic substrate that is partially and integrally formed,
The parylene thin film layer is formed on the surface of the difficult extension portion side, and
The organic thin film transistor element is a bottom gate top contact type 2V driving thin film transistor (TFT) using p-type semiconductor dinaphtho [2,3-b: 2 ′, 3′-f] thieno [3,2-b] thiophene (DNTT). ) And
The stretchable conductor is a stretchable conductor formed of a carbon nanotube rubber composition comprising single-walled carbon nanotubes, rubber and ionic liquid, and
The stretchable circuit board, wherein the plurality of organic thin film transistor elements are placed on the difficultly stretched portion of the substrate via the parylene thin film layer.   The stretchable circuit board according to claim 1, wherein the stretch characteristic has gradation in the vicinity of the interface between the hardly stretchable portion of the sheet-like stretchable organic base material and the stretchable base material.