WO2024070897A1 - Composition, film, circuit sheet, and sensor sheet - Google Patents

Abstract

With regard to a film for protecting the circuit wiring or the sensor electrode of a circuit sheet or a sensor sheet, the present invention makes it possible to form a protective film which has reduced thickness and has an exceptional ability to protect the circuit wiring or the sensor electrode. The present invention also obtains a composition for forming said film.　The present invention provides a composition that contains a COP resin or a COC resin, and an epoxy group–containing condensed polycyclic hydrocarbon monomer. The present invention alternatively provides a composition that contains a COP resin or a COC resin, a physical property adjusting material, and an epoxy group–containing condensed polycyclic hydrocarbon monomer. The present invention further provides a film that comprises the composition.

Description

Composition, film, circuit sheet and sensor sheet

This disclosure relates to a coating that can be used as a protective layer for a circuit sheet or a sensor sheet, a composition capable of forming the coating, and a circuit sheet and a sensor sheet that include the coating as a protective layer.

The conductive wires on the circuit sheet or the sensor electrodes on the sensor sheet are sometimes made from a silver paste containing silver, or a transparent conductive polymer called PEDOT/PSS. The circuit sheet or sensor sheet has a highly transparent protective layer covering its surface to protect the conductive wires or sensor electrodes from breakage, corrosion, etc.

However, silver paste or transparent conductive polymers are susceptible to deterioration due to water vapor and ultraviolet light, and sulfurization due to sulfur gas. For this reason, it is desirable for the protective layer to have properties that make it difficult for these phenomena to occur. Technology for covering conductive wires with a protective layer is described, for example, in Japanese Patent No. 6167103 (Patent Document 1).

Patent No. 6167103

As the fields in which circuit sheets and sensor sheets are used expand, there is a demand for circuit sheets or sensor sheets with even greater protective performance.

One aspect of the present disclosure is a composition containing a COP resin or a COC resin and an epoxy group-containing condensed polycyclic hydrocarbon monomer.
According to one aspect of the present disclosure, since the composition contains a COP resin or a COC resin, a film having excellent transparency and robustness can be formed. In addition, since the composition contains an epoxy group-containing condensed polycyclic hydrocarbon monomer, the composition can be cured to form a film having improved printability and quality. Furthermore, since the composition contains a solvent, a film can be formed by a method such as printing.

In one embodiment of the present disclosure, the epoxy group-containing condensed polycyclic hydrocarbon monomer is a cycloalkene oxide type condensed ring structure diepoxide.
According to one aspect of the present disclosure, since the epoxy group-containing condensed polycyclic hydrocarbon monomer is a cycloalkene oxide-type condensed ring-structure diepoxide, the composition can be cured to form a coating having excellent qualities such as printability, transparency, robustness, etc. In addition, since the epoxy group-containing condensed polycyclic hydrocarbon monomer is a cycloalkene oxide-type condensed ring-structure diepoxide, the coating has excellent adhesion to a substrate (e.g., a substrate sheet of a circuit sheet) when formed.

One embodiment of the present disclosure is a composition, wherein the epoxy group-containing condensed polycyclic hydrocarbon monomer is at least one selected from bicyclononadiene diepoxide, tricyclopentadiene diepoxide, dicyclopentadiene diepoxide, and 5,12-dioxahexacyclo[7.6.1.0 ^2,8 . 0 ^4,6 . 0 ^10,15 . 0 ^11,13 ]hexadecane.
According to one aspect of the present disclosure, the epoxy group-containing condensed polycyclic hydrocarbon monomer is at least any one selected from bicyclononadiene diepoxide, tricyclopentadiene diepoxide, ^{dicyclopentadiene} diepoxide, and ^5,12 -dioxahexacyclo[ ^{7.6.1.02,8.04,6.010,15.011,13} ] ^hexadecane , and therefore the formed coating has excellent adhesion to a substrate (e.g., a substrate sheet of a circuit sheet).

One aspect of the present disclosure is a composition further comprising a physical property adjuster.
According to one aspect of the present disclosure, the printability of the composition can be improved by containing a physical property adjusting agent. Furthermore, the quality of the film formed by curing the composition can be improved by containing a physical property adjusting agent.

One aspect of the present disclosure is a composition in which the blending ratio of the epoxy group-containing condensed polycyclic hydrocarbon monomer per 100 parts by mass of the COP resin or COC resin is 8 parts by weight or more and 35 parts by weight or less.
According to one aspect of the present disclosure, the blending ratio of the epoxy group-containing condensed polycyclic hydrocarbon monomer to the COP resin or COC resin is 8 parts by weight or more and 35 parts by weight or less, so that a coating can be formed that has high adhesion to the substrate (e.g., the substrate sheet of a circuit sheet) and is not easily peeled off from the substrate.

One aspect of the present disclosure is a composition in which the blending ratio of the physical property adjuster per 100 parts by weight of the COP resin or COC resin is 140 parts by weight or less.
According to one aspect of the present disclosure, the blending ratio of the physical property adjusting material per 100 parts by weight of the COP resin or COC resin is 140 parts by weight or less, so that the adhesion of the coating to the substrate (e.g., the substrate sheet of a circuit sheet) can be increased without deteriorating the heat resistance, sulfidation resistance, or bending whitening resistance or cracking resistance.

One aspect of the present disclosure is a coating formed from a reaction-cured product of any of the compositions described above.
According to one aspect of the present disclosure, the coating is made of a reaction-cured product of any one of the compositions described above, and therefore the coating can be of excellent quality.

One aspect of the present disclosure is a circuit sheet having a base sheet, circuit wiring, and a protective layer made of a reaction-cured product of any one of the compositions described above.
According to one aspect of the present disclosure, the circuit sheet has a base sheet, circuit wiring, and a protective layer made of a reaction-cured product of any of the compositions described above, and therefore can provide excellent protection for the circuit wiring sandwiched between the base sheet and the protective layer.

One aspect of the present disclosure is a circuit sheet having a three-dimensional shape with a curved surface.
According to one aspect of the present disclosure, since the circuit sheet has a three-dimensional shape with curved surfaces, the circuit sheet can be shaped to better fit the space it is to be used in. Therefore, according to one aspect of the present disclosure, the degree of freedom in designing a device that uses the circuit sheet is increased.

One aspect of the present disclosure may be a sensor sheet having a base sheet, circuit wiring, a sensor electrode, and a protective layer made of a reaction-cured product of any one of the compositions described above.
According to one aspect of the present disclosure, a sensor sheet is provided having a base sheet, circuit wiring, sensor electrodes, and a protective layer made of a reaction-cured product of any of the compositions described above, thereby providing a sensor sheet that is excellent in protecting the circuit wiring and sensor electrodes sandwiched between the base sheet and the protective layer.

One aspect of the present disclosure is a sensor sheet having a three-dimensional shape with a curved surface.
According to one aspect of the present disclosure, since the sensor sheet has a three-dimensional shape with a curved surface, the sensor sheet can be formed to better fit the space it is to be used in. Therefore, according to one aspect of the present disclosure, the degree of freedom in designing devices that use the sensor sheet is increased.

According to one aspect of the present disclosure, a printable composition can be provided.
According to one aspect of the present disclosure, a coating having excellent protective performance can be provided.
According to one aspect of the present disclosure, a circuit sheet or a sensor sheet having a coating with excellent protective performance can be provided.

1A and 1B are schematic diagrams of a circuit sheet according to one embodiment of the present disclosure, with FIG. 1A being a front view and FIG. 1B being a plan view. 2A and 2B are schematic diagrams of a sensor sheet according to one embodiment of the present disclosure, in which FIG. 2A is a front view and FIG. 2B is a plan view. 3A and 3B are schematic diagrams of a sensor sheet according to another embodiment of the present disclosure, in which FIG. 3A is a cross-sectional view taken along line IIIA-IIIA in FIG. 3B, and FIG. 3B is a plan view.

Below, an embodiment according to one aspect of the present disclosure will be described with reference to the drawings. The embodiment described below does not unduly limit the scope of the claims, and not all of the configurations described in this embodiment are necessarily essential as a solution to the present disclosure.

In one embodiment of the present disclosure, a "range" is defined in the form of a lower limit and an upper limit, and a "predetermined range" is defined by selecting one lower limit and one upper limit that specify the boundaries of the range. Such a defined range may or may not include the end values. That is, any lower limit and any upper limit may be combined to form a range. For example, if ranges of 5 to 10 and 6 to 9 are listed for a particular parameter, the ranges of 5 to 9 and 6 to 10 are also understood. If the minimum range values listed are 1 and 2, and the maximum range values listed are 3, 4, and 5, then the ranges of 1 to 3, 1 to 4, 1 to 5, 2 to 3, 2 to 4, and 2 to 5 are all contemplated. Unless otherwise specified in this disclosure, the numerical ranges "a to b" and "a to b" are shorthand for all real number combinations between a and b, where a and b are both real numbers. For example, a numerical range of "0 to 5" means that all real numbers between "0 and 5" are listed in this specification, with "0 to 5" being merely a shorthand for combinations of these numbers. Also, when a parameter is described as an integer ≧2, this is equivalent to disclosing that the parameter is, for example, the integers 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc.

All of the embodiments and optional embodiments contained in this disclosure may be combined with each other to form new technical solutions.

All technical features and optional technical features of this application may be combined with each other to form a new technical solution.

Unless otherwise stated, all steps in the methods of the present disclosure may be performed sequentially or randomly. For example, when the method includes steps Sa and Sb, it means that the method may include steps Sa and Sb performed sequentially, or may include steps Sb and Sa performed sequentially. For example, when the method may further include step Sc, it also means that step Sc can be added to the method in any order. For example, the method may include steps Sa, Sb, Sc, or may include steps Sa, Sc, Sb, or may include steps Sc, Sa, and Sb, etc.

As used in this disclosure, "comprise" and "include" refer to open forms and may also be closed forms. For example, the terms "comprise" and "include" may further include or include other ingredients not listed, or may include or include only the ingredients listed.

The term "or" as used in this disclosure is inclusive. For example, the phrase "A or B" means "A, B, or both A and B." More specifically, any of the following three conditions each satisfy "A or B": A is true (or exists) and B is false (or does not exist), A is false (or does not exist) and B is true (or exists), or A and B are both true (or exist).

In this specification and claims, when the terms "first," "second," ... "nth (n is any natural number)" are used, they are used to distinguish between different components, and are not used to indicate a specific order or superiority or inferiority. In addition, components that are common to each embodiment and have the same effect are given the same reference numerals and duplicated explanations are omitted.

<Composition>
The composition described in this embodiment is applied to a substrate sheet such as a circuit sheet or a sensor sheet to form a film, and is used as a protective layer for protecting circuit wiring (conductive wire) or sensor electrodes, and has high transparency and high protective performance for the object to be covered. This composition contains a COP resin or a COC resin and an epoxy group-containing condensed polycyclic hydrocarbon monomer. The composition of this composition will be described below.

COP resin or COC resin: When dissolved in a solvent, COP resin or COC resin has a high cohesive force and tends to form threads when used as a coating liquid such as printing ink, and is generally not suitable for printing. In addition, COP resin or COC resin has poor adhesion to resin films such as PET, which serve as base sheets, and is easily peeled off. Therefore, although COP resin or COC resin may be used as a pre-formed plate material, it is difficult to say that it is a binder resin suitable for printing, and it is difficult to use it as a coating liquid. However, since COP resin or COC resin is amorphous, it has the characteristics of high transparency and low birefringence. In addition, since COP resin or COC resin has an alicyclic structure, it has a high glass transition point Tg and is excellent in heat resistance and robustness. Furthermore, since COP resin or COC resin has a hydrocarbon structure with few polar groups, it has low moisture absorption and is also excellent in light resistance and chemical resistance. Therefore, the inventor of the present invention has considered how to use this COP resin or COC resin as a binder resin for coating materials.

COP resin or COC resin is a polymer with an alicyclic structure in the polymer main chain, and is obtained by polymerizing cycloolefin. COP resin is a ring-opening polymer of cycloolefins or a hydrogenated product thereof, and examples thereof include norbornene, tetracyclododecene, or derivatives thereof. COC resin is a cycloolefin copolymer, which is a copolymer of a cyclic olefin and an olefin, and examples thereof include copolymers in which a cyclopentyl residue or a substituted cyclopentyl residue is inserted in the molecular chain by polymerization of a cycloolefin such as norbornene, tetracyclododecene, or a derivative thereof, with ethylene or propylene. The cycloolefin used as the raw material for COP resin or COC resin may be monocyclic or polycyclic.

Hydrocarbon structures with fewer polar groups result in reduced hygroscopicity, but it is a preferred embodiment to use COP or COC resins that have polar groups in the cyclo ring in order to improve adhesion, adhesion, and miscibility. COP or COC resins with such polar groups are preferred in that they have good solubility in highly polar solvents, such as ethyl acetate and butyl acetate, and the types and amounts of compatible physical property adjusters can be increased. COP or COC resins may have functional groups such as hydroxyl, amino, carbonyl, carboxyl, nitro, sulfo, ester, and amide groups. Reactive functional groups such as epoxy, methacryl, vinyl, mercapto, and amino groups can improve the adhesion of the composition to the substrate sheet or circuit wiring to which it is applied.

Commercially available COP resins include, for example, Zeonex (registered trademark; manufactured by Zeon Corporation), Zeonor (registered trademark; manufactured by Zeon Corporation), and Arton (registered trademark; manufactured by JSR Corporation). Commercially available COC resins include, for example, Apel (registered trademark; manufactured by Mitsui Chemicals), and Topas (registered trademark; manufactured by Polyplastics).

The amount of COP resin or COC resin in the composition including the solvent can be 5% by weight or more and 70% by weight or less, preferably 20% by weight or more and 60% by weight or less. When the amount of COP resin or COC resin in the composition is 5% by weight or more, the desired thickness can be formed. Furthermore, when the amount is 70% by weight or less, the viscosity does not become too high and the composition has excellent printability. When the amount is 20% by weight or more and 60% by weight or less, the composition has suitable printability.

Epoxy group-containing condensed polycyclic hydrocarbon monomer: By adding an epoxy group-containing condensed polycyclic hydrocarbon monomer to a liquid in which a COP resin or COC resin has been dissolved or dispersed, the epoxy group-containing condensed polycyclic hydrocarbon monomer gives the liquid properties that cannot be obtained by simply dissolving or dispersing the COP resin or COC resin. As an example, by adding an epoxy group-containing condensed polycyclic hydrocarbon monomer to a COP resin or COC resin, the COP resin or COC resin can be used as a binder for coating materials such as printing ink. In addition, it is possible to maintain or improve adhesion to the base sheet, heat resistance, sulfurization resistance, resistance to whitening due to folding, cracking resistance, etc.

The epoxy group-containing condensed polycyclic hydrocarbon monomer is a monomer containing an epoxy group among condensed polycyclic hydrocarbons having a condensed ring hydrocarbon formed by two or more single rings supplying (condensing) only one side of each ring to each other, and is preferably a cycloalkene oxide type condensed ring structure diepoxide.

Specific examples of epoxy group-containing condensed polycyclic hydrocarbon monomers include bicyclononadiene diepoxide (1,2:5,6-diepoxyhexahydroindan) (Epocalic THI-DE (trade name) manufactured by ENEOS Corporation), 5,12-dioxahexacyclo[7.6.1.0 ^2,8 . 0 ^4,6 . 0 ^10,15 . 0 ^11,13 ]hexadecane (Epocalic DE-102 (trade name) manufactured by ENEOS Corporation), tricyclopentadiene diepoxide (5,12-dioxaheptacyclo[7.6.1.1 ^3,7 .0 ^2,8 .0 ^4,6 .0 ^10,15 .0 ^11,13 ]heptadecane) (Epocalic DE-103 (trade name) manufactured by ENEOS Corporation), dicyclopentadiene diepoxide (4,5:8,9-diepoxytricyclo[5.2.1.0 ^2,6 ]decane) (DCPD-DE (trade name) manufactured by Japan Material Technology Co., Ltd.), and the like.

These compounds have a more rigid skeleton than other epoxy group-containing monomers that do not have a condensed ring structure, and due to their alicyclic skeleton they have high light resistance, high heat resistance and low water absorption, and can function as light resistance improvers, heat resistance improvers and moisture resistance improvers. In addition, bicyclononadiene diepoxide (1,2:5,6-diepoxyhexahydroindan) also functions as a viscosity adjuster that reduces viscosity and a reactivity improver that shortens the curing reaction time.

The amount of epoxy group-containing condensed polycyclic hydrocarbon monomer can be 8 parts by weight or more and 35 parts by weight or less per 100 parts by weight of COP resin or COC resin, and can be 9 parts by weight, 10 parts by weight, 30 parts by weight, 31 parts by weight, 32 parts by weight, 33 parts by weight, or 34 parts by weight. When the amount of epoxy group-containing condensed polycyclic hydrocarbon monomer is 8 parts by weight or more per 100 parts by weight of COP resin or COC resin, adhesion to the base sheet and sulfurization resistance are excellent. On the other hand, when the amount of epoxy group-containing condensed polycyclic hydrocarbon monomer is 35 parts by weight or less per 100 parts by weight of COP resin or COC resin, adhesion to the base sheet, resistance to whitening due to bending, and resistance to cracking are excellent.

　Solvent: The solvent dissolves or disperses the COP resin or COC resin, and imparts an appropriate viscosity to the solution or dispersion, thereby resulting in a composition with properties suitable for the coating liquid. Such solvents include organic solvents such as hydrocarbons, aromatics, ethers, and ketones, and more specifically, pentane, hexane, octane, cyclohexane, methylcyclohexane, ethylcyclohexane, 1,2-dimethylcyclohexane, cyclohexene, toluene, xylene, ethyl ether, tetrahydrofuran, cyclohexanone, methyl ethyl ketone, methyl isobutyl ketone (MIBK), cyclohexyl propionate, 2-cyclohexyl-4-methyl-1,3-dioxane, terpineol, dihydroterpineol, dihydroterpinyl acetate, isobornyl acetate, isobornyl propionate, isobornyl butyrate, isobornyl isobutyrate, etc. Since COP resin or COC resin has polar groups in the molecular chain such as cyclo rings, it is preferable to use ester-based solvents such as ethyl acetate and butyl acetate. Solvents with high boiling points are preferable because they improve printability.

The amount of the solvent can be 25% by weight or more and 90% by weight or less, preferably 35% by weight or more and 80% by weight or less, based on the total amount of the composition. If the amount of the solvent in the composition is 25% by weight or more, the non-volatile components will not be too high, and the composition will have excellent printability. If the amount is 90% by weight or less, the non-volatile components will not be too low, and the composition can be formed to the desired thickness. If the amount is 35% by weight or more and 80% by weight or less, the composition will have suitable printability.

Physical property adjusters: Physical property adjusters are added to liquids in which COP resin or COC resin has been dissolved or dispersed, to give the liquid properties that cannot be obtained by simply dissolving or dispersing the polymer. In this respect, they are similar to epoxy group-containing condensed polycyclic hydrocarbon monomers, but in this specification and claims, when referring to physical property adjusters, this excludes epoxy group-containing condensed polycyclic hydrocarbon monomers.

Physical property adjusting agents include viscosity adjusting agents such as plasticizers, low molecular weight compounds, monomers, and oligomers that adjust the viscosity, thixotropy imparting agents that impart thixotropy, foam suppressing agents such as defoamers that suppress foaming during printing, stringing inhibitors that suppress stringing, wettability improving agents that prevent repellency on the printing substrate and prevent the occurrence of uneven printing and mottled patterns, cutting improving agents that enable continuous printing, and coating liquid stabilizers such as silane coupling agents, polymerization inhibitors, or antioxidants that stabilize the properties of the composition.

Furthermore, the physical property adjusting materials include film quality improving materials that improve the quality of the film itself, and smoothing materials that improve the surface smoothness when the film is formed. Also, from the viewpoint of the film functioning as a protective layer and protecting the quality of the conductive part that is covered inside, examples include moisture resistance improving materials that improve moisture resistance, sulfurization resistance improving materials that improve sulfurization resistance, gas barrier improving materials that suppress the permeability of gases such as oxygen, heat resistance improving materials that improve heat resistance, light resistance improving materials that prevent discoloration, ultraviolet light inhibitors that suppress the transmission of ultraviolet light, and adhesion improving materials that improve adhesion to the base sheet. Among these, moisture resistance improving materials, sulfurization resistance improving materials, gas barrier improving materials, heat resistance improving materials, light resistance improving materials, and ultraviolet light inhibitors from the viewpoint of a protective layer are included in weather resistance improving materials. They can also be said to be names that express the barrier improving materials in terms of their functions.

Examples of physical property adjusting agents include petroleum-based hydrocarbons such as aromatic, paraffinic, and naphthenic, polyolefins and their derivatives such as liquid polyisobutylene, liquid polybutene, and hydrogenated liquid polyisoprene, petroleum-based asphalts, etc. These substances improve printability and also improve film quality, such as weather resistance. These can be used alone or in combination.

Physical property adjusting materials having polar groups such as hydroxyl, amino, carbonyl, carboxyl, nitro, sulfo, ester, and amide groups are adhesion improving materials that contribute to improving the adhesion of the composition to the substrate sheet or circuit wiring to which it is applied. Physical property adjusting materials having reactive functional groups such as epoxy, methacryl, vinyl, mercapto, and amino groups contribute to improving the adhesion of the composition to the substrate sheet or circuit wiring to which it is applied.

Functional fillers such as titanium oxide or zinc oxide function as film quality improvers, such as moisture resistance improvers that suppress water vapor permeability, ultraviolet light inhibitors that suppress ultraviolet light transmission, sulfurization resistance improvers that suppress sulfur gas permeability, or gas barrier improvers. In addition, they also function as printability improvers, such as viscosity adjusters, foam inhibitors, or thixotropic agents.

Polyolefin resins such as maleic anhydride-modified polypropylene have adhesion to non-polar resins and function as an agent for improving adhesion to the base sheet and an agent for improving solvent resistance.
In addition, copolymers of isobutylene and maleic anhydride, copolymers of olefin resins and maleic anhydride, maleated hydrogenated styrene butadiene styrene block copolymers, etc. also have adhesion to non-polar resins and function as adhesion improvers to base sheets.

The amount of the physical property adjuster can be 140 parts by weight or less per 100 parts by weight of COP resin or COC resin, and can be 130 parts by weight, 120 parts by weight, 110 parts by weight, or 100 parts by weight. It is also preferable that the amount of the physical property adjuster is 80 parts by weight or more and 90 parts by weight or less. When the amount of the physical property adjuster is 140 parts by weight or less per 100 parts by weight of COP resin or COC resin, the resin has excellent sulfur resistance, permeability, and heat resistance. Furthermore, when the amount is 80 parts by weight or more and 90 parts by weight or less, the effect of adding the physical property adjuster can be fully expected, and a high transmittance can be obtained from the perspective of permeability.

Initiator: The initiator is added to react the COP resin or COC resin with the epoxy group-containing condensed polycyclic hydrocarbon monomer. To initiate polymerization using heat or light, a thermal polymerization initiator or a photopolymerization initiator is used. As a thermal radical polymerization initiator, an azo compound such as 2,2'-azobisisobutyronitrile (AIBN) or a peroxide such as benzoyl peroxide (BPO) can be used as an initiator. As a thermal cationic polymerization initiator, a sulfonium salt compound such as a benzenesulfonate ester or an alkylsulfonium salt can be used. The photopolymerization initiator generates active species such as radicals, cations, and anions, and photoradical initiators (such as benzoin derivatives) that generate radicals when irradiated with ultraviolet rays or electron beams, photoacid generators that generate cations (acids), and photobase generators that generate anions (bases) can be used. Among them, a thermal cationic polymerization initiator is preferable because it has excellent storage stability of the composition, and a sulfonium salt compound is particularly preferable. Examples of anions that pair with sulfonium salt compounds include phosphorus-based anions, antimony-based anions, and borate-based anions, with phosphorus-based anions being preferred because they pose fewer safety concerns.

The amount of initiator can be 0.1% by weight or more and 10.0% by weight or less based on the epoxy group-containing condensed polycyclic hydrocarbon monomer. If it is 0.1% by weight or more, the epoxy group-containing condensed polycyclic hydrocarbon monomer can be sufficiently reacted. Also, if it is 10.0% by weight or less, there is no waste because no initiator that does not contribute to the curing reaction of the monomer is included.

　Preparation of the composition: The composition is prepared by dissolving or dispersing the COP resin or COC resin in a solvent, adding and mixing the epoxy group-containing condensed polycyclic hydrocarbon monomer and, if desired, a physical property adjusting agent. The viscosity of the obtained composition, measured using a rotational viscometer at a rotation speed of 5 rpm and 25°C, is preferably 0.1 Pa·s or more and 300 Pa·s or less, and can be appropriately changed depending on the application method. For example, when spray application is performed, it is preferable to set the viscosity to 0.1 Pa·s or more and less than 1.0 Pa·s, when applying by screen printing or a coater, it is preferable to set the viscosity to 1.0 Pa·s or more and less than 5.0 Pa·s, and when applying by a dispenser, it is preferable to set the viscosity to 5.0 Pa·s or more and less than 300 Pa·s. If the viscosity of the composition is 0.1 Pa·s or more, the coating liquid will not flow from the desired application surface. Also, if the viscosity is 300 Pa·s or less, the composition spreads well on the application surface. The viscosity can be adjusted by adjusting the amount of the solvent or physical property adjusting agent, or by adding a filler, etc.

The composition described above has a suitable viscosity and is suitable for printing on a substrate sheet. Furthermore, the composition is less likely to produce pinholes or the like during application, such as printing, and can form a smooth film. In addition, when the composition hardens, it forms a film that can function as a high-quality protective layer.

　Film formation: The composition can be applied by screen printing or the like to a base sheet made of a resin film or the like, and solidified to form a film that can function as a protective layer for the base sheet. The protective layer can be a highly transparent film due to the properties of the COP or COC resin. The average light transmittance of the protective layer in the visible light range of 400 nm to 800 nm can be preferably 80% or more, more preferably 85% or more. In addition to screen printing, other application methods that can be used include spray application, dispenser application, coater printing, transfer printing, and immersion methods.

The thickness of the film as a protective layer that protects the circuit wiring or sensor electrodes can be 0.5 μm to 50 μm, preferably 3 μm to 30 μm, and more preferably 5 μm to 15 μm. The thickness of the film as a protective layer can also be greater than 50 μm. However, a film that is too thick goes against the demand for thin films. On the other hand, if the film is 3 μm or thicker, it is possible to protect the circuit wiring or sensor electrodes. Furthermore, the film can be laminated to increase the thickness. This makes it possible to thicken the film to about 100 μm.

The coating has excellent moisture resistance, light resistance, and sulfuration resistance, low reactivity to chemicals, and solvent barrier properties. The coating itself is low volatile and does not bleed out. In addition, the coating does not migrate to other components that adhere to the surface of the coating, does not attack resins, and is less likely to contaminate these other components.

In another embodiment of the present disclosure, a composition having a desired viscosity can be prepared by mixing pulverized solid COP resin or COC resin with an epoxy group-containing condensed polycyclic hydrocarbon monomer without using a solvent, and adding a viscosity adjuster that does not dissolve the COP resin or COC resin.
In yet another embodiment, a composition can be prepared by mixing a pulverized solid COP resin or COC resin with an epoxy group-containing condensed polycyclic hydrocarbon monomer without using a solvent or a viscosity modifier.
All of these embodiments may be combined, and both may be added to compensate for insufficient solvent function with a viscosity modifier.

<Circuit sheet>
An embodiment of a circuit sheet having a protective layer that protects the circuit wiring provided on the base sheet by forming a coating film by applying a composition on the base sheet is shown in a front view in Fig. 1A and a plan view in Fig. 1B. The circuit sheet 10 shown in these figures is formed by applying a composition to cover conductive wires 12 provided on a base sheet 11 to form a protective layer 13, and these figures show only one conductive wire 12 that forms a circuit. Note that the thickness is shown thicker than the width in the drawings in order to clearly show the layer structure, so the aspect ratio is different from the actual one.

　Base sheet: It is preferable to use a transparent resin film for the base sheet 11, which is the base material of the circuit sheet. Examples of such resin films include polyethylene terephthalate (PET) resin, polyethylene naphthalate (PEN) resin, polycarbonate (PC) resin, methacrylic (PMMA) resin, polypropylene (PP) resin, polyurethane (PU) resin, polyamide (PA) resin, polyethersulfone (PES) resin, polyetheretherketone (PEEK) resin, triacetylcellulose (TAC) resin, and COP resin (cycloolefin polymer). A film made of a composition may also be used as the base sheet 11. Alternatively, the base sheet 11 may be provided with a primer layer for improving adhesion with the conductive wire 12 or protective layer 13, a surface protective layer, or an overcoat layer for the purpose of antistatic, or may be surface-treated by corona treatment, plasma treatment, ultraviolet irradiation, or the like.

Circuit wiring: For ease of explanation, only one conductive wire 12 that constitutes the circuit wiring is shown in FIG. 1, but generally, such conductive wires 12 are arranged in a pattern on the base sheet 11 to form a circuit (circuit wiring network). Examples of materials for the conductive wires 12 include conductive pastes and conductive inks that contain powder of highly conductive metals such as copper, aluminum, silver, or alloys containing these metals. Of these metals and alloys, it is preferable to use silver wiring that mainly uses silver because it has high conductivity and is less susceptible to oxidation than copper. The conductive wires 12 can also be wiring that uses graphite powder, carbon powder such as carbon fiber or carbon black, or wiring made from materials that mix these with metals.

In addition to printing, the circuit wiring can be formed by forming conductive parts on the base sheet 11 using metal vapor deposition, and then generating a circuit pattern by etching or the like. When performing metal vapor deposition, metals such as copper, aluminum, nickel, chromium, zinc, and gold can be used. Of these, copper is preferred because of its low electrical resistance and low cost.

The circuit sheet 10 is manufactured by printing circuit wiring (conductive wires 12) at predetermined locations on a transparent resin film that serves as the base sheet 11. A composition is then applied onto the circuit wiring and cured to form a protective layer 13. In this manner, the circuit sheet 10 can be obtained. If the COP resin or COC resin, epoxy group-containing condensed polycyclic hydrocarbon monomer, or physical property adjuster contains a reactive functional group, it can also be reacted with the base film.

<Sensor sheet (part 1)>
Another embodiment having a coating formed by applying the composition onto a base sheet as a protective layer is shown in the front view of Fig. 2A and the plan view of Fig. 2B. A sensor sheet 20 such as a capacitance sensor sheet shown in these figures is formed by applying a composition so as to cover conductive wires 22 and sensor electrodes 24 provided on a base sheet 21 to form a protective layer 23. Here, only one sensor electrode 24 is shown for convenience, and an explanation is given as an example of a sensor sheet 20 having the sensor electrode 24 together with circuit wiring.

Sensor electrode: The base sheet 21 or conductive wire 22 that serves as the base material for the sensor sheet 20 is the same as that used for the circuit sheet 10. The sensor electrode 24 can be formed from a conductive paste or conductive ink that forms circuit wiring, a metal deposition film, etc., but it can also be formed from a transparent conductive polymer, etc. If a highly transparent material is used, it becomes possible to illuminate the sensor position by transmitting backlight illumination.

Examples of transparent conductive polymers include polythiophene, polypyrrole, polyaniline, polyparaphenylene, and polyacetylene. Specific examples include PEDOT/PSS (poly-3,4-ethylenedioxythiophene-polystyrene sulfonic acid). Transparent conductive polymers that are commercially available as paints or printing inks can be used. Alternatively, the sensor electrode 24 can be made using a conductive paste or ink that contains a highly transparent material, such as metal nanoparticles such as silver nanoparticles, carbon nanoparticles, or indium tin oxide (ITO) powder.

The sensor sheet 20 is manufactured by printing circuit wiring (conductive wires 22) and sensor electrodes 24 at predetermined locations on a transparent resin film that serves as a base sheet 21. A composition is then applied onto the substrate, and the solvent is evaporated and cured to form a protective layer 23. In this manner, the sensor sheet 20 can be obtained.

<Sensor sheet (part 2)>
Another embodiment of the sensor sheet 30 is shown in a cross-sectional view seen from the front direction in Fig. 3A and a plan view in Fig. 3B. The sensor sheet 30 shown in these figures is the same as the sensor sheet 20 described above in that the circuit wiring (conductive wires 32) and the sensor electrodes 34 on the base sheet 31 are covered with a protective layer 33 formed by applying a composition. However, the sensor sheet 30 of this embodiment is different in that it is bent or stretched on an uneven surface to be formed into a three-dimensional shape having a curved surface. The raw materials of each component can be selected in the same way.

The sensor sheet 30 can be formed by forming the circuit wiring (conductive wires 32), the sensor electrodes 34, and the protective layer 33 on a flat base sheet 31 in the same manner as the sensor sheet 20, and then thermally deforming the same, or by forming the circuit wiring (conductive wires 32), the sensor electrodes 34, and the protective layer 33 on the base sheet 31 formed into a three-dimensional shape by printing or deposition, etc. When the base sheet 31 is thermally deformed in a later process, it is preferable that the glass transition point Tg of the COP resin or COC resin contained in the composition that will become the protective layer 33 is close to the glass transition point Tg of the base sheet 31. This is because the closer the glass transition points Tg are, the more similar the deformation of the base sheet 31 and the protective layer 33 will be, and distortion, deformation, cracking, etc. will be less likely to occur.

<Sensor sheet (part 3)>
The sensor sheet may be formed into a three-dimensional shape having a curved surface by bending or stretching the uneven surface, and then covered with a protective layer. The protective layer can be provided by applying a composition to the three-dimensional surface using a spray coating method or the like.

<Sensor sheet (part 4)>
The sensor sheet may be integrated with a resin housing on its upper or lower surface. The integration of the sensor sheet and the resin housing may be achieved by a bonding method using a pressure sensitive adhesive or a bonding agent, a method of engaging with an engaging structure provided on the resin housing, or an integral molding method such as insert molding.

It will be readily apparent to those skilled in the art that many modifications are possible that do not substantially depart from the novel features and effects of the present invention. Therefore, all such modifications are included in the scope of the present invention. For example, a term described at least once in the specification or drawings together with a different term having a broader or similar meaning can be replaced with that different term anywhere in the specification or drawings. Furthermore, the configuration of the embodiment is not limited to that described in the above embodiment, and various modifications are possible.

<Preparation of Samples 1 to 68>
Next, the present disclosure will be further described based on examples (comparative examples). The materials shown in the following tables were mixed in the amounts (parts by weight) shown in each table to prepare compositions as samples 1 to 68. In addition, a PET film was used as a base sheet, and a conductive film having a thickness of 0.5 μm was formed on the surface of the film using PEDOT/PSS (trade name: Orgacon EL-P3145, manufactured by AGFA) and a conductive wire having a thickness of 7 μm was formed in parallel using silver paste (trade name: FA-323, manufactured by Fujikura Kasei Co., Ltd.). Then, on the surface of the base sheet on which these conductive films and conductive wires were formed, any of the compositions of samples 1 to 68 was applied to a thickness of 10 μm, and the resulting mixture was heated and cured at 90° C. to prepare a test circuit sheet having a film covering the conductive film and conductive wire. However, at both ends of the conductive film, no film was provided for resistance measurement, and exposed portions (exposed portions) of the conductive film were provided. The same sample number as the composition applied was assigned to each of the obtained test circuit sheets.

In each table, the type of base polymer "COP resin" is a COP resin (cycloolefin copolymer, product name: R-5000, manufactured by JSR Corporation, Tg 137°C).
"Monomer A" is an epoxy group-containing condensed polycyclic hydrocarbon monomer (bicyclononadiene diepoxide, trade name: Epocalic THI-DE, manufactured by ENEOS Corporation),
"Monomer B" is an epoxy group-containing condensed polycyclic hydrocarbon monomer (5,12-dioxahexacyclo[7.6.1.0 ^2,8 .0 ^4,6 .0 ^10,15 .0 ^11,13 ]hexadecane, product name: Epocalic DE-102, manufactured by ENEOS Corporation),
"Monomer C" is an epoxy group-containing condensed polycyclic hydrocarbon monomer (tricyclopentadiene diepoxide, also known as 5,12-dioxaheptacyclo[7.6.1.1 ^3,7 .0 ^2,8 .0 ^4,6 .0 ^10,15 .0 ^11,13 ]heptadecane, product name: Epocalic DE-103, manufactured by ENEOS Corporation),
As "monomer D", an epoxy group-containing condensed polycyclic hydrocarbon monomer (dicyclopentadiene diepoxide, also known as 4,5:8,9-diepoxytricyclo[5.2.1.0 ^2,6 ]decane, trade name: DCPD-DE, manufactured by Japan Material Technology Co., Ltd.) was used.

Further, as the epoxy group-containing monomer,
"Monomer E" is an epoxy group-containing alicyclic monomer (3',4'-epoxycyclohexylmethyl 3,4-epoxycyclohexanecarboxylate, trade name: CELLOXIDE 2021P, manufactured by Daicel Corporation),
As "monomer F", an epoxy group-containing alicyclic monomer (1,2-epoxy-4-(2-oxiranyl)cyclohexane adduct of 2,2-bis(hydroxymethyl)-1-butanol, trade name: EHPE3150CE, manufactured by Daicel Corporation) was used.

As the "physical property adjusting material", polyolefin resin (maleic anhydride modified polypropylene, product name: Surflen P-1000, manufactured by Mitsubishi Chemical Corporation) was used.
As the "initiator", a thermal cationic polymerization initiator (sulfonium salt compound, trade name: San-Aid SI-300, manufactured by Sanshin Chemical Industry Co., Ltd.) was used.
As the "solvent", dihydroterpinyl acetate (boiling point 225°C) was used.

<Various tests>
The samples were subjected to the various tests described below.

[Printability] Viscosity: To measure printability, the viscosity of each sample composition was measured using a rotational viscometer (Brookfield rotational viscometer DV-E) (spindle SC4-14, chamber SC4-6R/RP, rotation speed 5 rpm, measurement temperature 25°C). The results are shown in the "Printability (viscosity)" column of each table. The viscosity values in the tables indicate Pa·s.

　[Film quality 1] Adhesion: In order to evaluate the film quality from the viewpoint of adhesion to the base sheet, the cross-cut method was performed on each sample based on JIS K5600-5-6:1999 to perform an adhesion test. More specifically, a single-blade cutting tool (a typical Olfa cutter) was used to make multiple 1 mm-wide lattice-shaped cuts in the film, and a 24 mm-wide transparent pressure-sensitive adhesive tape (product name: Cellotape (registered trademark) CT-24, manufactured by Nichiban Co., Ltd.) was applied to the surface of the film and then peeled off.

The results are shown in the "Adhesion" column of each table. In each table, six numbers from 0 to 5 indicate the classification of the test results using the cross-cut method. Classification 0 is when there is no peeling of any of the grids, Classification 1 is when there is small peeling of the coating at the intersections of the cuts but does not clearly exceed 5%, Classification 2 is when the coating has peeled off at the intersections along the cut lines but the peeling covers between 5% and 15% of the entire area where the tape is applied, Classification 3 is when the coating has peeled off partially or completely along the cut lines and the peeling is between 15% and 35%, Classification 4 is when there is large peeling of the coating partially or completely along the cut lines and the peeling is between 35% and 65%, and Classification 5 is when the adhesion exceeds Classification 4. Therefore, if it is 0 or 1, the adhesion is good.

　[Film quality 2] Moisture and heat resistance: In order to evaluate the film quality from the viewpoint of moisture and heat resistance, a moisture and heat resistance test was conducted on each of the above samples. More specifically, the test circuit sheet of each sample was left in an atmosphere of 85% humidity and 85°C temperature for 250 hours, 500 hours, 750 hours, and 1000 hours, and the color of the conductive film made of transparent conductive polymer was observed after each time, and the moisture and heat resistance was evaluated from the change in color. At the same time, moisture and heat resistance was also evaluated from the change in resistance value of the conductive film made of transparent conductive polymer after each time. The "Moisture and heat resistance color change" column in each table shows the color difference ΔE after 1000 hours. The "Moisture and heat resistance resistance change rate" column in each table also shows the resistance change rate Δ after 1000 hours.

The color change of the conductive film was evaluated as color difference ΔE based on an index defined as the distance between coordinates in the CIE1976 L*a*b* color space in accordance with JIS Z 8781-4. This color difference can be determined, for example, using a handy spectrophotometer ("JX777" manufactured by Color Techno Systems Co., Ltd.) or a color difference meter ("CR-400" manufactured by Konica Minolta, Inc.). The resistance value was measured using a resistance meter (tester) from the exposed parts at both ends of the conductive film made of transparent conductive polymer.

　[Film quality 3] Heat resistance: In order to evaluate the film quality from the viewpoint of heat resistance, a heat cycle test was conducted on the test circuit sheet of each sample. More specifically, each test circuit sheet was placed in a thermo-hygrostat with a temperature setting range of -40°C to +85°C, a heating rate of 3°C/min, and a cooling rate of 2°C/min. Heat resistance was then evaluated from the change in color and resistance value of the conductive film made of transparent conductive polymer after 1000 hours. The "Heat resistance color change" column in each table shows the color difference ΔE after 1000 hours. Additionally, the "Heat resistance resistance change rate" column in each table shows the resistance change rate Δ after 1000 hours.

　[Film quality 4] Sulfuration resistance: A sulfuration resistance test was conducted to evaluate the film quality from the viewpoint of sulfuration resistance. More specifically, each test circuit sheet was placed in an airtight space containing sulfur powder and left in a saturated sulfur vapor atmosphere at 85°C for 250 hours. After 250 hours, the condition of the conductive wire made of silver paste was observed visually and by measuring the resistance value. Those that remained at a low resistance value compared to before the sulfuration resistance test and did not break were rated as "A", and those that showed blackened areas across the entire width of the conductive wire and were judged to have broken because the resistance value exceeded 2 MΩ, the maximum value that can be displayed on the tester, were rated as "C".

　[Film quality 5] Resistance to whitening and cracking due to bending: In order to evaluate the quality of the film from the viewpoint of film strength, the condition of the base film on which the film was formed was observed when it was bent. If it was strong enough to not whiten or crack even when bent 30 times at 180 degrees with a radius of 1 mm, it was rated as "A". If it was strong enough to not crack even when bent 30 times at 180 degrees with a radius of 1 mm, but the bent parts turned white, it was rated as "B". If the film cracked when folded in half with a radius of 1 mm, it was rated as "C".

　[Film quality 6] Transparency: In order to evaluate the film quality from the transparency of the film, the composition of each sample was applied to a PET film to form a film with a thickness of 8 μm to 25 μm. The film was then measured for parallel light transmittance at wavelengths of 200 nm to 800 nm using a spectrophotometer (Shimadzu Corporation's "UV-1900i"). A transmittance of 80% or more was rated as "A," a transmittance of 70% to less than 80% was rated as "B," and a transmittance of less than 70% was rated as "C."

<Considerations>
Based on the results of each of the above tests, the following considerations were made.

[Printing suitability] Viscosity: The viscosity of each sample in each table was greater than or equal to 1.0 Pa·s and less than 5.0 Pa·s, indicating that all samples had suitable viscosities for screen printing.

　[Film quality 1] Adhesion: From the adhesion test, there was no effect due to the difference in material, whether the base sheet was PET or PC. However, it was found that differences occurred depending on the type of epoxy-containing monomer. In the samples using the epoxy-containing alicyclic monomers E and F, all samples except for sample 54, which was monomer E with 10.0 parts by weight of a property modifier added, were rated 2 or higher for adhesion, and suitable adhesion was not obtained. On the other hand, in the samples using the epoxy-containing condensed polycyclic hydrocarbon monomers A, B, C, or D, except for sample 17 and sample 18, the monomer content was 0 or 1 when it was 10% or more and 30% or less of the COP resin content. However, when the monomer content was 5% or less or 50%, it was rated 2 or more. In addition, although the monomer content of sample 17 and sample 18 was 20%, the property modifier was contained in an amount of 7.5 parts by weight or more, and it was found that excessive mixing of the property modifier had a negative effect on adhesion.

In addition, sample 27, which contains 40% of monomer B, an epoxy group-containing condensed polycyclic hydrocarbon monomer, relative to the COP resin content, had an adhesion of 2, but sample 40, which contains 40% of monomer B but has a property-adjusting agent added, had an adhesion of 0, a dramatic improvement in adhesion. The same results were obtained when comparing other samples that differ only in the presence or absence of a property-adjusting agent.

[Film quality 2] Moisture and heat resistance: From the viewpoint of moisture and heat resistance, the addition of property-adjusting agents appears to be somewhat undesirable, but it was favorable when the content of epoxy-containing condensed polycyclic hydrocarbon monomer was in the range of 10% to 40%. On the other hand, it was found that the heat resistance of samples using epoxy-containing alicyclic monomers was easily deteriorated by the addition of property-adjusting agents.

　[Film quality 3] Heat resistance When examining each sample from the standpoint of heat resistance, the results were almost the same as those for moist heat resistance. In other words, the addition of a property-adjusting agent appears to be slightly undesirable, but it was preferable when the content of epoxy-containing condensed polycyclic hydrocarbon monomer was in the range of 10% to 40% of the COP resin content. On the other hand, it was found that the addition of a property-adjusting agent tended to deteriorate heat resistance in samples that used epoxy-containing alicyclic monomers.

[Film quality 4] Sulfuration resistance: From the viewpoint of sulfuration resistance, the same can be said as for adhesion, and the evaluation was C when the epoxy group-containing condensed polycyclic hydrocarbon monomer content was 5% or less of the COP resin content, and the content of physical property adjusters was 150% (7.5 parts by weight) or more of the COP resin content. It was also found that when epoxy-containing alicyclic monomers were used, the resistance was more likely to deteriorate than when epoxy group-containing condensed polycyclic hydrocarbon monomers were used.

[Film quality 5] Resistance to whitening due to bending, resistance to cracking: From the viewpoint of film strength, if the content of epoxy group-containing condensed polycyclic hydrocarbon monomer is 40% or more of the COP resin content, it may be rated as C, but if it is 30% or less, it is rated as A, and it is found to have resistance to whitening due to bending and resistance to cracking. From this, it was found that if the content of epoxy group-containing condensed polycyclic hydrocarbon monomer is 30% or less of the COP resin content, bending processing and thermoforming into three-dimensional shapes can be carried out without any problems.

[Film quality 6] Transmittance: Looking at the transmittance, samples 16 and 36, which contain 5.0 parts by weight of property-adjusting agent, were rated B, indicating that the amount of property-adjusting agent added should be 4.0 parts by weight or less, i.e., 80% or less of the COP resin content.

10 Circuit sheet 11 Base sheet 12 Conductive wire (circuit wiring)
13 Protective layer (film)
20: sensor sheet 21: base sheet 22: conductive wire (circuit wiring)
23 Protective layer (film)
24 Sensor electrode 30 Sensor sheet 31 Base sheet 32 Conductive wire (circuit wiring)
33 Protective layer (film)
34 Sensor electrode

Claims (11)

1. A composition containing a COP resin or a COC resin and an epoxy group-containing condensed polycyclic hydrocarbon monomer.
2. 2. The composition according to claim 1, wherein the epoxy group-containing condensed polycyclic hydrocarbon monomer is a cycloalkene oxide type condensed ring diepoxide.
3. The composition according to claim 1 or 2, wherein the epoxy group-containing condensed polycyclic hydrocarbon monomer is at least one selected from the group consisting of bicyclononadiene diepoxide, tricyclopentadiene diepoxide, dicyclopentadiene diepoxide, and 5,12-dioxahexacyclo[7.6.1.0 ^2,8 . ^{0 4,6} . 0 ^10,15 . 0 ^11,13 ]hexadecane.
4. The composition according to any one of claims 1 to 3, further comprising a property adjusting material.
5. 5. The composition according to claim 4, wherein the mixing ratio of said physical property adjusting agent per 100 parts by weight of said COP resin or COC resin is 140 parts by weight or less.
6. The composition according to any one of claims 1 to 5, wherein the mixing ratio of the epoxy group-containing condensed polycyclic hydrocarbon monomer to 100 parts by weight of the COP resin or COC resin is 8 parts by weight or more and 35 parts by weight or less.
7. A coating formed by reaction and curing the composition described in any one of claims 1 to 6.
8. A base sheet;
   Circuit wiring,
   A circuit sheet having a protective layer made of a reaction-cured product of the composition according to any one of claims 1 to 6.
9. The circuit sheet according to claim 8 , wherein the circuit sheet has a three-dimensional shape having a curved surface.
10. A base sheet;
    Circuit wiring,
    A sensor electrode;
    A sensor sheet having a protective layer made of a reaction-cured product of the composition according to any one of claims 1 to 6.
11. The sensor sheet according to claim 10 , wherein the sensor sheet has a three-dimensional shape having a curved surface.

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