Composition for forming a release layer and a release layer

Abstract

To provide a photocurable composition for peeling layer formation which enables formation of a device composed of a resin substrate on a peeling layer, and gives the peeling layer easily peeled at an interface between the peeling layer and the device composed of the resin substrate.SOLUTION: A composition for peeling layer formation contains (A) a polymer cured by light irradiation which has, for example, a photodemerized structural site such as a cinnamoyl group.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to a composition for forming a release layer and a release layer, and more specifically, to a composition for forming a release layer that is cured by light irradiation and a release layer obtained by photocuring the composition.

Background Art

[0002] In recent years, in addition to the characteristics of thinning and lightening, electronic devices are required to have a function of being bendable. For this reason, instead of the conventional heavy, fragile, and non-bendable glass substrate, it is required to use a lightweight flexible plastic substrate.

[0003] In particular, in next-generation displays, the development of active matrix full-color TFT display panels using lightweight flexible plastic substrates (hereinafter also referred to as resin substrates) is required. In addition, for touch panel type displays, materials corresponding to flexibility, such as transparent electrodes of touch panels and resin substrates used in combination with display panels, have been developed. As transparent electrodes, other transparent electrode materials have been proposed, such as transparent conductive polymers such as PEDOT, metal nanowires, and their mixed systems, instead of ITO that has been conventionally used (Patent Documents 1 to 4).

[0004] On the other hand, the base material of the touch panel film has also changed from glass to a sheet made of plastic such as polyethylene terephthalate (PET), polyimide, cycloolefin, or acrylic, and a transparent flexible touch screen panel with flexibility has been developed (Patent Documents 5 to 7).

[0005] Generally, a flexible touch screen panel is produced by forming a release (adhesive) layer on a support substrate such as a glass substrate to ensure stable productivity and peelability, and then peeling off a device composed of a resin substrate or the like after it is formed (Patent Document 8).

[0006] As the release layer, for example, a curable resin compound containing a predetermined polymer and a crosslinking agent is described (Patent Documents 9 to 10). While these release layers can be easily peeled off from the support substrate, since they peel at the interface between the support substrate and the release layer, the release layer may remain on the device side and have an adverse effect on the device manufacturing process and permeability.

Prior Art Documents

Patent Documents

[0007]

Patent Document 1

Patent Document 2

Patent Document 3

Patent Document 4

Patent Document 5

Patent Document 6

Patent Document 7

Patent Document 8

Patent Document 9

Patent Document 10

Summary of the Invention

Problems to be Solved by the Invention

[0008] The present invention has been made in view of the above circumstances, and an object thereof is to provide a photocurable composition for forming a release layer that can form a device composed of a resin substrate or the like on the release layer and provides a release layer that can be easily peeled at the interface between the release layer and the device composed of the resin substrate or the like.

Means for Solving the Problems

[0009] As a result of intensive studies to achieve the above object, the present inventors have found that a composition for forming a release layer containing a polymer curable by light irradiation can form a device composed of a resin substrate or the like on the release layer by light irradiation, and can reproducibly provide a release layer that easily peels at the interface between the release layer and the device composed of a resin substrate or the like, and thus completed the present invention.

[0010] That is, the present invention provides: 1. A composition for forming a release layer, characterized by containing a polymer curable by light irradiation (A); 2. The composition for forming a release layer according to 1, wherein the polymer (A) curable by light irradiation is a polymer having a structural site that undergoes photodimerization; 3. The composition for forming a release layer according to 1 or 2, wherein the structural site that undergoes photodimerization is a cinnamoyl group; 4. The composition for forming a release layer according to any one of 1 to 3, wherein the polymer (A) curable by light irradiation is a polymer obtained by using a monomer having a structural site that undergoes photodimerization; 5. The composition for forming a release layer according to any one of 1 to 4, wherein the polymer (A) curable by light irradiation is a polymer obtained by using a monomer selected from the group consisting of an acrylate compound, a methacrylate compound, a maleimide compound, an acrylamide compound, acrylonitrile, maleic anhydride, a styrene compound, and a vinyl compound; 6. The polymer (A) curable by light irradiation is a polymer obtained by using a monomer having a structural site that undergoes photodimerization together with a monomer having no structural site that undergoes photodimerization, wherein the content of the monomer having a structural site that undergoes photodimerization is 1 to 50 mol% with respect to 100 mol% of all monomer units, and the content of the monomer having no structural site that undergoes photodimerization is 50 to 99 mol% with respect to 100 mol% of all monomer units, and the composition for forming a release layer according to 4 or 5; 7. The composition for forming a release layer according to 6, wherein the monomer having no structural site that undergoes photodimerization is a monomer having an alicyclic hydrocarbon group; 8. A release layer formed by photocuring any of the release layer-forming compositions of 1 to 7 9. A laminate in which a resin layer having a light transmittance of 80% or more at a wavelength of 400 nm is laminated on the release layer of 8 10. The laminate of 9, wherein the resin layer is a thermosetting film containing an epoxy compound 11. A method for producing a laminate, comprising applying any of the release layer-forming compositions of 1 to 7 onto a substrate and then performing exposure to form a release layer 12. A step of applying any of the release layer-forming compositions of 1 to 7 onto a substrate, exposing the composition to form a release layer, a step of forming a resin substrate having a light transmittance of 80% or more at a wavelength of 400 nm on the release layer, and a step of peeling the resin substrate with a peeling force of 1.0 N / 25 mm or less A method for producing a resin substrate comprising the steps is provided.

Advantages of the Invention

[0011] By using the release layer-forming composition of the present invention, a device composed of a resin substrate or the like can be formed on the release layer, and a release layer that can be easily peeled at the interface between the release layer and the device composed of the resin substrate or the like can be obtained with good reproducibility by light irradiation. Further, in the manufacturing process of a flexible electronic device, the resin substrate formed on the substrate and the circuit provided thereon can be separated from the substrate together with the circuit without damaging the resin substrate or the circuit. Therefore, the release layer-forming composition of the present invention can contribute to speeding up the manufacturing process of a flexible electronic device provided with a resin substrate and improving its yield.

Embodiments for Carrying Out the Invention

[0012] Hereinafter, the present invention will be described in more detail. [Release Layer-Forming Composition] The release layer-forming composition of the present invention is characterized by containing (A) a polymer that cures by light irradiation. [1] Component (A) Component (A) in the composition for forming a release layer of the present invention is a polymer that cures upon light irradiation. The polymer that cures upon light irradiation is preferably a polymer having a structural moiety that undergoes photodimerization. Examples of the structural moiety that undergoes photodimerization include a cinnamoyl group, a chalcone group, a coumarin group, an anthracene group, etc. Among them, the cinnamoyl group is preferred due to its high photodimerization reactivity. Examples of suitable substituents containing a cinnamoyl group and a cinnamoyl structure include structures represented by the following formula [1] or formula [2]. In this specification, groups in which the benzene ring in the cinnamoyl group is a naphthalene ring are also included in the "cinnamoyl group" and "substituents containing a cinnamoyl structure".

[0013]

Chemical formula

[0014] In the above formula [1], X 1 represents an alkyl group having 1 to 18 carbon atoms, a phenyl group, or a biphenyl group. In the above formula [2], X 2 represents a hydrogen atom, a cyano group, an alkyl group having 1 to 18 carbon atoms, a phenyl group, a biphenyl group, or a cyclohexyl group, X 1 and X 2 in which, the phenyl group and the biphenyl group may be substituted with a halogen atom or a cyano group, and X 1 and X 2 may be a combination in which a plurality of an alkyl group having 1 to 18 carbon atoms, a phenyl group, a biphenyl group, and a cyclohexyl group are bonded via one or more bonds selected from a covalent bond, an ether bond, an ester bond, an amide bond, a urea bond, a urethane bond, an amino bond, a carbonyl, and combinations thereof. In the above formula [1] and formula [2], A represents any one of the following formula [A1], formula [A2], formula [A3], formula [A4], formula [A5], and formula [A6].

[0015] [Chemistry]

[0016] In the above formulas [A1] to [A6], R 1 ~R 8 each independently represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, a halogen atom, a trifluoromethyl group, or a cyano group. The alkyl group having 1 to 4 carbon atoms may be linear, branched, or cyclic, and specific examples thereof include methyl, ethyl, n-propyl, i-propyl, n-butyl, t-butyl groups, and the like. The alkoxy group having 1 to 4 carbon atoms may have a linear, branched, or cyclic alkyl group therein, and specific examples thereof include methoxy, ethoxy, n-propoxy, i-propoxy, n-butoxy, t-butoxy groups, and the like. Examples of the halogen atom include fluorine, chlorine, bromine, and iodine atoms.

[0017] To introduce such a photo-dimerizable structural site into a polymer, methods such as polymerizing a monomer having a photo-dimerizable structural site can be mentioned, but the present invention is not limited thereto.

[0018] Examples of the monomer having a photo-dimerizable structural site include acrylic acid ester compounds, methacrylic acid ester compounds, maleimide compounds, acrylamide compounds, acrylonitrile, maleic anhydride, styrene compounds, vinyl compounds, etc. having a photo-dimerizable structural site. Preferably, acrylic acid ester compounds and methacrylic acid ester compounds having a structure represented by the above formula [1] or formula [2] are suitable. Preferable examples of the monomer having a photo-dimerizable structural site include compounds represented by the following formulas M1-1 to M1-13, but are not limited thereto. The monomer having a photo-dimerizable structural site may be used alone or in combination of two or more.

[0019] [Chemical formula]

[0020] [Chemical formula] (In the formula, M 1 is a hydrogen atom or a methyl group, s1 represents the number of methylene groups and is a natural number from 2 to 9, and R is methoxy or ethoxy.)

[0021] The polymer that cures upon light irradiation of component (A) in the composition for forming a release layer of the present invention may contain a monomer having a structure site that undergoes photodimerization (structural unit (a)) and a monomer having no structure site that undergoes photodimerization (structural unit (b)). The monomer of structural unit (b) is not particularly limited as long as it is copolymerizable with structural unit (a), and examples thereof include acrylate compounds, methacrylate compounds, maleimide compounds, acrylamide compounds, acrylonitrile, maleic anhydride, styrene compounds, vinyl compounds, and the like.

[0022] Specific examples of the acrylate compound include methyl acrylate, ethyl acrylate, isopropyl acrylate, benzyl acrylate, naphthyl acrylate, anthryl acrylate, anthryl methyl acrylate, phenyl acrylate, glycidyl acrylate, 2,2,2-trifluoroethyl acrylate, tert-butyl acrylate, cyclohexyl acrylate, isobornyl acrylate, 2-methoxyethyl acrylate, methoxy triethylene glycol acrylate, 2-ethoxyethyl acrylate, tetrahydrofurfuryl acrylate, 3-methoxybutyl acrylate, 2-methyl-2-adamantyl acrylate, 2-propyl-2-adamantyl acrylate, 8-methyl-8-tricyclodecyl acrylate, 8-ethyl-8-tricyclodecyl acrylate, and the like.

[0023] Specific examples of the methacrylic acid ester compound include methyl methacrylate, ethyl methacrylate, isopropyl methacrylate, benzyl methacrylate, naphthyl methacrylate, anthryl methacrylate, anthryl methyl methacrylate, phenyl methacrylate, glycidyl methacrylate, 2,2,2-trifluoroethyl methacrylate, tert-butyl methacrylate, cyclohexyl methacrylate, isobornyl methacrylate, 2-methoxyethyl methacrylate, methoxytriethylene glycol methacrylate, 2-ethoxyethyl methacrylate, tetrahydrofurfuryl methacrylate, 3-methoxybutyl methacrylate, stearyl methacrylate, adamantyl methacrylate, 2-methyl-2-adamantyl methacrylate, γ-butyrolactone methacrylate, 2-propyl-2-adamantyl methacrylate, 8-methyl-8-tricyclodecyl methacrylate, 8-ethyl-8-tricyclodecyl methacrylate, and the like.

[0024] Specific examples of the vinyl compound include methyl vinyl ether, benzyl vinyl ether, vinyl naphthalene, vinyl carbazole, allyl glycidyl ether, 3-ethenyl-7-oxabicyclo[4.1.0]heptane, 1,2-epoxy-5-hexene, 1,7-octadiene monoepoxide, and the like. Specific examples of the styrene compound include styrene, methyl styrene, chlorostyrene, bromostyrene, and the like. Specific examples of the maleimide compound include maleimide, N-methyl maleimide, N-phenyl maleimide, N-cyclohexyl maleimide, and the like.

[0025] In particular, from the viewpoints of the heat resistance and hydrophobicity of the resulting release layer, the monomer of structural unit (b) is preferably a monomer having an alicyclic hydrocarbon group, and more preferably a (meth)acrylic acid ester having an alicyclic hydrocarbon group with 6 to 20 carbon atoms. Examples of the alicyclic hydrocarbon group include a cyclohexyl group, a t-butylcyclohexyl group, an isobornyl group, a dicyclopentanyl group, a dicyclopentenyl group, an adamantyl group, and the like. Specific examples of the monomer having an alicyclic hydrocarbon group include isobornyl methacrylate, isobornyl acrylate, dicyclopentanyl methacrylate, dicyclopentanyl acrylate, dicyclopentenyl methacrylate, dicyclopentenyl acrylate, adamantyl methacrylate, cyclohexyl methacrylate, t-butylcyclohexyl methacrylate, and the like. Note that the monomers of structural unit (b) may be used alone or in combination of two or more of the same kind.

[0026] (A) In the polymer obtained by using a monomer (structural unit (a)) having a photo-dimerizable structural site, the content of the monomer of structural unit (a) is preferably 1 to 70 mol%, more preferably 3 to 50 mol%, and even more preferably 5 to 30 mol% with respect to 100 mol% of all monomer units. When the content of the monomer of structural unit (a) of the crosslinking agent is too small, the solvent resistance and heat resistance of the release layer may decrease, and the releasability may decrease. On the other hand, when the content is too large, the reaction with the resin substrate or the like on the release layer may proceed, and the releasability may decrease.

[0027] The method for obtaining the polymer used in the composition for forming a release layer of the present invention is not particularly limited. For example, a method of reacting in a solvent in which a monomer of structural unit (a), a monomer of structural unit (b), a polymerization initiator, etc. coexist at a temperature of 50 to 110 °C can be mentioned. For this polymerization reaction, a solvent that dissolves the monomer of structural unit (a), the monomer of structural unit (b), the polymerization initiator, etc. may be used, and specific examples thereof include the solvents listed in the section [Solvent] below.

[0028] The obtained polymer is usually in a state of a solution dissolved in a solvent. In the present invention, the powdery polymer taken out from the solvent may be used as the component (A), or the obtained polymer solution may be used as the component (A) as it is. Further, a solution obtained by redissolving the powdery polymer taken out from the solvent in a solvent may be used as the component (A). Also, as a method for taking out the polymer from the solution of the polymer obtained as described above, for example, the polymer solution is mixed with a poor solvent such as hexane, diethyl ether, water, etc. under any stirring to reprecipitate the polymer, and the generated precipitate is filtered and washed, and then dried under normal pressure or reduced pressure at normal temperature or under heating to obtain a powder. By such an operation, not only the solvent but also the polymerization initiator and unreacted monomer coexisting with the polymer can be removed, and as a result, a purified polymer powder can be obtained. If purification is not sufficient by a single operation, the obtained powder may be redissolved in a solvent and the above operation may be repeated.

[0029] In the composition for forming a release layer of the present invention, as the polymer of the component (A), a single type of polymer or a mixture of a plurality of types of polymers may be used.

[0030] [2] Other additives The composition for forming a release layer of the present invention may contain other additives as necessary as long as the effects of the present invention are not impaired. Examples of other additives include surfactants, silane coupling agents, rheology modifiers, pigments, dyes, storage stabilizers, antifoaming agents, antioxidants, and the like. In particular, from the viewpoint of enhancing the coatability with respect to the substrate, the composition for forming a release layer of the present invention preferably contains a surfactant. As the surfactant, known surfactants such as nonionic surfactants, fluorine-based surfactants, and silicone-based surfactants can be used.

[0031] Specific examples of nonionic surfactants include polyoxyethylene alkyl ethers such as polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, polyoxyethylene cetyl ether, and polyoxyethylene oleyl ether; polyoxyethylene alkyl aryl ethers such as polyoxyethylene octyl phenyl ether and polyoxyethylene nonyl phenyl ether; polyoxyethylene - polyoxypropylene block copolymers; sorbitan fatty acid esters such as sorbitan monolaurate, sorbitan monopalmitate, sorbitan monostearate, sorbitan monooleate, sorbitan trioleate, and sorbitan tristearate; and polyoxyethylene sorbitan fatty acid esters such as polyoxyethylene sorbitan monolaurate, polyoxyethylene sorbitan monopalmitate, polyoxyethylene sorbitan monostearate, polyoxyethylene sorbitan trioleate, and polyoxyethylene sorbitan tristearate, etc.

[0032] Specific examples of fluorine - based surfactants include Eftop (registered trademark) EF301, EF303, EF352 (manufactured by Mitsubishi Materials Electronic Chemicals Co., Ltd.), Megafac (registered trademark) F171, F173, F554, F559, F563, R - 30, R - 40, R - 40 - LM, DS - 21 (manufactured by DIC Corporation), Fluorad FC430, FC431 (manufactured by 3M Company), Asahi Guard (registered trademark) AG710, Surfron (registered trademark) S - 382, SC101, SC102, SC103, SC104, SC105, SC106 (manufactured by Asahi Glass Co., Ltd.), etc. Specific examples of silicone - based surfactants include organosiloxane polymer KP341 (manufactured by Shin - Etsu Chemical Co., Ltd.), etc.

[0033] These surfactants may be used alone or in combination of two or more. When using a surfactant, its amount used is preferably 0.0001 to 1 part by mass, more preferably 0.001 to 0.5 part by mass, based on 100 parts by mass of the polymer (A).

[0034] [3] Solvent The composition for forming a release layer of the present invention may contain a solvent. As the solvent, as long as it has the solubility of the component (A), the component (B) used as necessary, and / or other additives, the type, structure, etc. thereof are not particularly limited. In the present invention, glycol ether solvents having 3 to 20 carbon atoms, ester solvents having 3 to 20 carbon atoms, ketone solvents having 3 to 20 carbon atoms, and amide solvents having 3 to 20 carbon atoms are preferable.

[0035] Specific examples of the glycol ether solvent include propylene glycol monomethyl ether (PGME), propylene glycol monomethyl ether acetate (PGMEA), propylene glycol monoethyl ether, propylene glycol monopropyl ether, and the like. Specific examples of the ester solvent include ethyl lactate, γ-butyrolactone, methyl 2-hydroxyisobutyrate, ethyl 2-hydroxyisobutyrate, and the like. Specific examples of the ketone solvent include methyl ethyl ketone, cyclohexanone, cyclopentanone, benzophenone, and the like. Specific examples of the amide solvent include N-methylpyrrolidone, N,N-dimethylacetamide, 3-methoxy-N,N-dimethylpropanamide, and the like. The solvent may be used alone or in combination of two or more.

[0036] The content of the solvent is preferably an amount such that the solid content concentration in the composition for forming a release layer of the present invention is 0.1 to 40% by mass, more preferably an amount such that it is 0.5 to 20% by mass, and even more preferably an amount such that it is 0.5 to 10% by mass. The solid content is a general term for those other than the solvent among all the components of the composition for forming a release layer.

[0037] The method for preparing the composition for forming a release layer of the present invention is not particularly limited. For example, a method of mixing other additives at a predetermined ratio into a solution of component (A) dissolved in a solvent to form a uniform solution, or a method of further adding and mixing other additives as needed at an appropriate stage of the above preparation method can be mentioned. In addition, the solution of the composition for forming a release layer prepared is preferably filtered using a filter having a pore size of about 0.2 μm or the like before use.

[0038] The viscosity of the composition for forming a release layer of the present invention is appropriately set in consideration of the thickness of the release layer to be produced, etc. However, particularly when the purpose is to reproducibly obtain a film having a thickness of about 0.01 to 5 μm, usually, at 25 ° C, about 1 to 5,000 mPa·s is preferable, and about 1 to 2,000 mPa·s is more preferable.

[0039] Here, the viscosity can be measured using a commercially available viscometer for measuring the viscosity of a liquid, for example, referring to the procedure described in JIS K7117-2, under the condition that the temperature of the composition is 25 ° C. Preferably, as the viscometer, a cone-plate type rotational viscometer is used. Preferably, using the same type of viscometer and 1°34’×R24 as the standard cone rotor, the measurement is carried out under the condition that the temperature of the composition is 25 ° C. Examples of such a rotational viscometer include TVE-25L manufactured by Toki Sangyo Co., Ltd.

[0040] [Release layer] The release layer can be obtained by a method including a heating step of applying the composition for forming a release layer of the present invention described above onto a substrate to form a coating film and then heating it, and an exposure step of irradiating light such as ultraviolet light after the heating step. In this case, the heating time varies depending on the temperature and cannot be generally specified, but it is usually 1 minute to 5 hours. As a preferable example of the heating mode, a method of heating at 50 to 150 ° C for 1 minute to 1 hour can be mentioned. Note that the heating temperature may include a step of heating at a temperature lower than the above range as long as the maximum temperature is within the above range.

[0041] The light irradiation such as ultraviolet light is arbitrary in terms of its conditions as long as the component (A) is photocured. For example, a method of irradiating ultraviolet light at a level of 500 to 2,000 mJ / cm 2 is mentioned, such as irradiating ultraviolet light to this extent.

[0042] When forming the release layer of the present invention on a substrate, the release layer may be formed on a part of the surface of the substrate or on the entire surface. As an aspect of forming a release layer on a part of the surface of the substrate, there are aspects such as forming a release layer only in a predetermined range of the substrate surface, and forming a release layer in a pattern such as a dot pattern or a line-and-space pattern on the entire surface of the substrate. In the present invention, the substrate means that the composition for forming the release layer of the present invention is coated on its surface, and it is used in the manufacture of flexible electronic devices and the like.

[0043] Also, when irradiating light such as ultraviolet light, a mask having a predetermined pattern is attached to irradiate light such as ultraviolet light, and by developing with an alkaline developer or the like, unexposed portions are developed, and a release layer can be formed in a pattern such as a line-and-space pattern.

[0044] Examples of the substrate (base material) include glass, metal (such as a silicon wafer), and slate. In particular, since the release layer obtained from the composition for forming the release layer of the present invention has sufficient adhesion to it, glass is preferred. Note that the substrate surface may be composed of a single material or may be composed of two or more materials. As an aspect in which the substrate surface is composed of two or more materials, in a certain range of the substrate surface, it is composed of a certain material, and the remaining surface is composed of other materials. There are aspects such as a pattern in which a material such as a dot pattern or a line-and-space pattern exists in other materials on the entire substrate surface.

[0045] The coating method is not particularly limited. For example, there are a cast coating method, a spin coating method, a blade coating method, a dip coating method, a roll coating method, a bar coating method, a die coating method, an inkjet method, a printing method (letterpress, gravure, lithography, screen printing, etc.).

[0046] Examples of the instrument used for heating include, for example, a hot plate, an oven, etc. The heating atmosphere may be under air or under an inert gas, and may be under normal pressure or under reduced pressure. Examples of the device used for light irradiation include, for example, a high-pressure mercury lamp, a metal halide lamp, etc.

[0047] The thickness of the release layer is usually about 0.01 to 50 μm, preferably about 0.01 to 20 μm, more preferably about 0.01 to 5 μm from the viewpoint of productivity, and the desired thickness is realized by adjusting the thickness of the coating film before heating.

[0048] The release layer of the present invention has good releasability of the resin substrate provided thereon. Therefore, the release layer of the present invention can be suitably used in the manufacturing process of a flexible electronic device to peel the resin substrate together with a circuit or the like formed on the resin substrate from the substrate without damaging the resin substrate of the device.

[0049] An example of a method for manufacturing a flexible electronic device using the release layer of the present invention will be described. First, using the composition for forming the release layer of the present invention, a release layer is formed on a glass substrate by the aforementioned method. A solution for forming a resin substrate for forming a resin substrate is applied on this release layer, and the obtained coating film is fired to form a resin substrate fixed to the glass substrate through the release layer of the present invention.

[0050] The firing temperature of the coating film is appropriately set according to the type of resin and the like. In the present invention, it is preferable that the maximum temperature during this firing is 200 to 250 °C, more preferably 210 to 250 °C, and even more preferably 220 to 240 °C. By setting the maximum temperature during firing when manufacturing the resin substrate within this range, the releasability between the release layer and the resin substrate can be further improved. Also in this case, as long as the maximum temperature is within the above range, a step of firing at a temperature lower than that may be included.

[0051] The resin substrate is preferably formed with an area larger than the area of the release layer so as to entirely cover the release layer. Examples of the resin substrate include a resin substrate made of an acrylic polymer and a resin substrate made of a cycloolefin polymer. The method for forming the resin substrate may follow a conventional method. Further, as the resin substrate, those having a light transmittance of 80% or more at a wavelength of 400 nm are preferable.

[0052] Next, a desired circuit is formed, if necessary, on the resin substrate fixed to the substrate via the release layer of the present invention. Then, for example, the resin substrate is cut along the release layer, and the resin substrate together with this circuit is peeled off from the release layer to separate the resin substrate from the substrate. At this time, a part of the substrate may be cut together with the release layer. By using the release layer of the present invention, the resin substrate can be peeled off from the release layer with a peeling force of 1.0 N / 25 mm or less.

Examples

[0053] Hereinafter, the present invention will be described in more detail with reference to synthesis examples, preparation examples, examples, and comparative examples, but the present invention is not limited to the following examples.

[0054] The meanings of the abbreviations used in the following examples are as follows. 〔Polymer raw materials〕 ADMA: 2 - Adamantyl methacrylate DCPMA: Dicyclopentanyl methacrylate AIBN: Azobisisobutyronitrile

[0055] Cin1: A compound represented by the following formula

Chemical formula

[0056] Cin2: A compound represented by the following formula

Chemical formula

[0057] 〔Solvents〕 CHN: Cyclohexanone

[0058] [Measurement of Polymer Molecular Weight] The molecular weight of the acrylic copolymer in the synthesis example was measured as follows using a normal temperature gel permeation chromatography (GPC) apparatus (GPC-101) manufactured by Shodex Corporation and columns (KD-803, KD-805) manufactured by Shodex Corporation. The following number average molecular weight (hereinafter referred to as Mn) and weight average molecular weight (hereinafter referred to as Mw) were expressed as polystyrene conversion values. Column temperature: 40 °C Eluent: Tetrahydrofuran Flow rate: 1.0 mL / min Standard sample for calibration curve preparation: Standard polystyrene (molecular weights of approximately 197,000, 55,100, 12,800, 3,950, 1,260, 580) manufactured by Showa Denko K.K.

[0059] (1) Synthesis of Component (A) [Synthesis Example 1] 3.50 g (15.89 mmol) of ADMA as a non-crosslinkable monomer, 1.38 g (3.97 mmol) of Cin1 as a crosslinkable monomer, and 0.10 g (0.60 mmol) of AIBN as a polymerization catalyst were dissolved in 50.0 g of THF, and reacted under heating and reflux for 20 hours to obtain an acrylic copolymer solution. The acrylic copolymer solution was gradually dropped into 500.0 g of hexane to precipitate a solid, and the acrylic polymer (PA-1) was obtained by filtration and drying under reduced pressure. The Mw of the obtained acrylic copolymer was 15,000.

[0060] [Synthesis Examples 2 - 6] Polymers (PA-2) - (PA-6) were obtained by operating in the same manner as in Synthesis Example 1 except that the types and amounts of the raw material compounds were as shown in Table 1 below. The Mw of the obtained polymers is shown in Table 1.

[0061]

Table 1

[0062] (2) Preparation of Composition for Forming Resin Substrate [Preparation Example 1] Preparation of Composition F1 for Forming Resin Substrate To a eggplant flask containing 100 g of carbon tetrachloride as a solvent, 10 g of Zeonor (registered trademark) 1020R (cycloolefin polymer manufactured by Zeon Corporation, Japan) and 3 g of Epolead (registered trademark) GT401 (manufactured by Daicel Corporation) were added. This solution was stirred and dissolved for 24 hours under a nitrogen atmosphere to prepare Composition F1 for forming a resin substrate.

[0063] (3) Preparation of Composition for Forming Release Layer [Example 1-1] CHN was added to 100 parts by mass of the polymer (PA-1) obtained in Synthesis Example 1 which is Component (A) to prepare Composition (A-1) for forming a release layer having a solid content concentration of 5.0% by mass.

[0064] [Examples 1-2 to 1-5, Comparative Example 1-1] Release layer forming compositions A-2 to A-12 were prepared in the same manner as in Example 1-1, except that the types and amounts of the respective components were as described in Table 2.

[0065] [Table 2]

[0066] (4) Production of Release Layer and Resin Substrate [Example 2-1] The release layer forming composition A-1 prepared in Example 1-1 was applied onto a glass substrate (Eagle XG manufactured by Corning, 100 mm × 100 mm × 0.7 mm, the same applies hereinafter) as a substrate using a spin coater (condition: rotation speed 2,000 rpm for about 30 seconds). The obtained coating film was heated at 100 °C for 2 minutes using a hot plate, and then irradiated with ultraviolet rays at 2,000 mJ / cm 2 to form a release layer having a thickness of about 0.1 μm on the glass substrate, thereby obtaining a glass substrate with a release layer. Subsequently, using a spin coater (condition: rotating at 200 rpm for about 15 seconds), the composition F1 for forming a resin substrate was applied onto the release layer (resin thin film) on the glass substrate. The obtained coating film was heated at 80°C for 2 minutes using a hot plate, and then heated at 230°C for 30 minutes using a hot plate to form a resin substrate with a thickness of about 3 μm on the release layer, thereby obtaining a glass substrate with a resin substrate and a release layer.

[0067] [Examples 2-2 to 2-5, Comparative Example 2-1] The same operations as in Example 2-1 were performed except that (A-2) to (A-6) were used as the release layer forming composition, and glass substrates with resin substrates and release layers of Examples 2-2 to 2-5 and Comparative Example 2-1 were obtained.

[0068] [Comparative Example 2-2] The same operations as in Example 2-1 were performed except that ultraviolet irradiation was not performed using a high-pressure mercury lamp, and a glass substrate with a resin substrate and a release layer of Comparative Example 2-2 was obtained.

[0069] [Evaluation of Peeling Force] The glass substrate with the resin substrate and the release layer obtained above was cut into strips of 25 mm × 50 mm using a cutter. Further, after sticking cellophane tape (registered trademark) (CT-24 manufactured by Nichiban Co., Ltd.), peeling was performed at a peeling angle of 90° and a peeling speed of 300 mm / min using an autograph AGS-X500N (manufactured by Shimadzu Corporation) to measure the peeling force. Those that could not be peeled were regarded as non-peelable. The evaluation results were regarded as "peeling force", and the results are summarized in Table 3.

[0070] [Evaluation of Peeling Interface] The thickness of the release layer remaining on the glass substrate after the evaluation of the peeling force was measured using a stylus type film thickness meter. Comparison was made with the film thickness at the time of forming the release layer to determine the peeling interface. The evaluation results were regarded as "peeling interface". When the residual film ratio (residual film ratio (%) = film thickness of the release layer after peeling / film thickness of the release layer at the time of forming the release layer × 100) was 90% or more, it was the release layer / resin interface; when it was 10% or more and less than 90%, it was the cohesive failure of the release layer; when it was less than 10%, it was the glass substrate / release layer interface. The evaluation results are summarized in Table 3.

[0071]

Table 3

[0072] As shown in Table 3, it can be seen that the release layers of the respective examples exhibit low release force and are excellent in releasability. Further, it was confirmed that the release layers of the examples peel at the interface between the release layer and the resin substrate. On the other hand, it can be seen that the films of Comparative Examples 2-1 and 2-2 do not function as release layers.

Claims

1. A composition for forming a release layer that is interposed between a substrate and a resin substrate and forms a release layer that peels off at the interface with the resin substrate, (A) containing a polymer that cures by light irradiation, The polymer is a polymer obtained using a monomer having a structure site that undergoes photo-dimerization, The monomer having a structure site that undergoes photo-dimerization is one or more selected from an acrylate compound and a methacrylate compound having a substituent containing a cinnamoyl group or a cinnamoyl structure represented by the following formula [1] or formula [2], and is characterized in that the composition for forming a release layer. 【Chemical 1】 〔In formula [1], X 1 represents an alkyl group having 1 to 18 carbon atoms, a phenyl group or a biphenyl group, In formula [2], X 2 represents a hydrogen atom, a cyano group, an alkyl group having 1 to 18 carbon atoms, a phenyl group, a biphenyl group or a cyclohexyl group, In formula [1] and formula [2], A represents any one of the following formula [A1], formula [A2], formula [A3], formula [A4], formula [A5] and formula [A6]. [Chemical Formula 2] (In Formulae [A1] to [A6], R 1 to R 8 each independently represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, a halogen atom, a trifluoromethyl group or a cyano group.)]]

2. The composition for forming a release layer according to claim 1, wherein in the formula [1] and the formula [2], A represents the formula [A1].

3. The composition for forming a release layer according to claim 1 or 2, wherein the monomer having a structure site that undergoes photo-dimerization is one or more selected from an acrylate compound and a methacrylate compound having a substituent containing a cinnamoyl group or a cinnamoyl structure represented by the formula [1].

4. The polymer (A) that cures by light irradiation is a polymer obtained using a monomer having a structure site that does not undergo photo-dimerization together with a monomer having a structure site that undergoes photo-dimerization, The content of the monomer having a structure site that undergoes photo-dimerization is 1 to 50 mol% based on 100 mol% of all monomer units, and the content of the monomer having no structure site that undergoes photo-dimerization is 50 to 99 mol% based on 100 mol% of all monomer units. The composition for forming a release layer according to any one of claims 1 to 3.

5. The composition for forming a release layer according to claim 4, wherein the monomer having no structure site that undergoes photo-dimerization is a monomer having an alicyclic hydrocarbon group.

6. A release layer obtained by photocuring the composition for forming a release layer according to any one of claims 1 to 5.

7. A laminate in which a resin layer having a light transmittance of 80% or more at a wavelength of 400 nm is laminated on the release layer according to claim 6.

8. The laminate according to claim 7, wherein the resin layer is a thermosetting film containing an epoxy compound.

9. A method for manufacturing a laminate, comprising applying the composition for forming a release layer according to any one of claims 1 to 5 on a substrate and then performing exposure to form a release layer.

10. A step of applying the composition for forming a release layer according to any one of claims 1 to 5 to a substrate, exposing the substrate to form a release layer, a step of forming a resin substrate having a light transmittance of 80% or more at a wavelength of 400 nm on the release layer, and a step of peeling the resin substrate with a peeling force of 1.0 N / 25 mm or less A method for manufacturing a resin substrate, comprising the steps.

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