JP2014129491A - Sheet-shaped adhesive, adhesive laminate and method for producing flexible member - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sheet-shaped adhesive in which the generation of bubbles is controllable with an opposite material even after being subjected to a heating step and having satisfactory adhesion properties, an adhesive laminate provided therewith, and a method for producing a flexible member using the sheet-shaped adhesive.SOLUTION: Provided is a sheet-shaped adhesive in which, after the heating of a laminate obtained by pasting a polyethylene naphthalate film with a sheet-shaped adhesive at 180°C for 30 min, bubbles are not substantially present on the grain boundaries between the polyethylene naphthalate film and the sheet-shaped adhesive.

Description

  The present invention relates to a sheet-like pressure-sensitive adhesive, a pressure-sensitive adhesive laminate, and a method for producing a flexible member.

  In recent years, as members in electronic devices and displays, for example, flexible circuit boards (FPC), base substrates in organic EL panels, TFTs (drive circuits) in displays, color filters, touch panel circuit boards, and solar cells, etc. Development of a thin flexible member having impact resistance is in progress.

  In conventional flat devices, patterns are formed on a highly rigid glass substrate, so handling such as fixing and transporting of the substrate can be performed accurately and easily, which allows pattern formation on the substrate without problems. It can be carried out.

  On the other hand, in developing the flexible member as described above, a pattern is formed not on a conventional glass substrate but on a flexible substrate such as a so-called heat-resistant metal foil, plastic substrate, or ultrathin glass. . However, since the flexible substrate alone has low rigidity and inferior handling properties, or the thermal dimensional stability of the flexible substrate itself is inferior, it is difficult to form a highly accurate pattern. A technique is proposed in which a flexible substrate is separately fixed to a hard substrate via a temporary fixing material, a pattern is formed thereon, and then the processed flexible substrate is peeled from the temporary fixing material (patent). Reference 1).

JP 2012-186315 A

  In the above technique, since the flexible substrate, the adhesive layer as the temporary fixing material, and the hard substrate are integrally formed, the adhesive layer is also affected by the heat treatment at that time. If the influence of heat treatment cannot be ignored, bubbles (voids) may be generated between the adhesive and the flexible substrate or hard substrate, and a desired pattern may not be formed. It turns out.

  The present invention solves a newly found problem in processing of a flexible member, and can suppress the generation of bubbles with a counterpart material even after a heating step and has good adhesion. It aims at providing the manufacturing method of a flexible member using a sheet-like adhesive, an adhesive laminated body provided with this, and this sheet-like adhesive.

  The inventors of the present application have conducted intensive studies and found that the object can be achieved by adopting the following configuration, and have completed the present invention.

  In the present invention, a laminate obtained by bonding a polyethylene naphthalate film (hereinafter also referred to as “PEN film”) and a sheet-like pressure-sensitive adhesive is heated at 180 ° C. for 30 minutes, and then the polyethylene naphthalate film and the sheet-like material. It is a sheet-like pressure-sensitive adhesive having substantially no bubbles at the interface with the pressure-sensitive adhesive.

  The sheet-like pressure-sensitive adhesive is substantially free of bubbles at the interface with the counterpart PEN film even after being heated at 180 ° C. for 30 minutes. Can be processed. In the present specification, “substantially no bubbles” means that no bubbles having a maximum diameter of 500 μm or more are generated at the interface with the counterpart material. The procedure for confirming the presence or absence of bubbles is as described in the examples.

  In the said sheet-like adhesive, after heating the laminated body which bonded the glass rigid board | substrate and the said sheet-like adhesive for 30 minutes at 180 degreeC, it is substantially in the interface of the said glass rigid board | substrate and the said sheet-like adhesive. Preferably no bubbles are present. As a result, it is possible to substantially eliminate air bubbles at the interface with the glass hard substrate, which is the opposite material on the opposite side of the object to be processed, and to suppress air bubbles at both interfaces of the sheet-like adhesive. A flexible substrate can be processed stably and with high accuracy.

  The Young's modulus at 25 ° C. of the sheet-like adhesive after heating the sheet-like adhesive at 180 ° C. for 30 minutes is preferably 0.5 MPa or more. It is considered that bubbles at the interface between the sheet-like pressure-sensitive adhesive as the temporary fixing material and the counterpart material are mainly caused by outgas such as moisture contained in each member. The Young's modulus after the predetermined heat treatment of the sheet-like pressure-sensitive adhesive is 0.5 MPa or more, and the sheet-like pressure-sensitive adhesive has an appropriate hardness in the processing step. Leakage to the interface can be prevented and generation of bubbles can be efficiently suppressed. In addition, the measuring method of Young's modulus is based on description of an Example.

  The said sheet-like adhesive may contain the curable composition hardened | cured by heating or energy ray irradiation. Since the curable composition can be cured by heating or energy beam irradiation, the sheet-like pressure-sensitive adhesive has an appropriate hardness before or during the processing of the flexible substrate in which outgas leaks to the interface. And can prevent outgas leakage at a higher level and efficiently.

  In the said sheet-like adhesive, the one part or all hardening reaction of the said curable composition may advance by a 1st hardening process. Thereby, the hardening degree of a curable composition can be adjusted by a 1st hardening process, and the hardness of the said sheet-like adhesive can be set to the level requested | required efficiently. In addition, when the first curing process is heating, it is not necessary to provide a separate process for curing the curable composition by replacing the first curing process with a heating process when processing the flexible substrate. Existing processes can be used effectively.

In the sheet-like pressure-sensitive adhesive, the curable composition contains a carbon-carbon double bond as a curable functional group,
It is preferable that the residual ratio of the carbon-carbon double bond after heating the sheet-like pressure-sensitive adhesive at 180 ° C. for 30 minutes is 60% or less.

  When the curable composition is cured through a carbon-carbon double bond as a curable functional group, the cured composition until the residual ratio of the carbon-carbon double bond after a predetermined heat treatment is 60% or less. When the product is cured, the hardness of the sheet-like pressure-sensitive adhesive can be made moderate, and the generation of bubbles can be suppressed.

In the sheet-like pressure-sensitive adhesive, a partial curing reaction of the curable composition proceeds by the first curing treatment,
It is preferable that the curing reaction of the remainder of the curable composition proceeds by the second curing process performed after the first curing process.

  By curing the curable composition in two steps, in the first curing process, the hardness of the sheet-like pressure-sensitive adhesive is appropriately adjusted to prevent leakage to the outgas interface, and in the second curing process. It is possible to design a process in which the adhesive strength of the sheet-like pressure-sensitive adhesive is reduced by curing and the subsequent flexible substrate is easily peeled off.

  As a hardening process of the curable composition of the said sheet-like adhesive, it is preferable that said 1st hardening process is heating and said 2nd hardening process is energy beam irradiation. When performing process design to prevent leakage of outgas to the interface in the first curing process and to achieve easy peeling due to a decrease in the adhesive strength of the sheet adhesive in the second curing process, the first curing Heat treatment during processing of the flexible substrate can be used by making the treatment heat, and the curing reaction mechanism between the two hardening treatments by making the second curing treatment energy beam irradiation different from heating The degree of curing in the first curing process and the second curing process can be set to an appropriate level according to the process design.

  The sheet-like pressure-sensitive adhesive preferably contains 100 ppm or more of a radical generator that generates radicals by heating or energy beam irradiation. Thereby, when hardening of a curable composition is performed via a carbon-carbon double bond, especially the hardening reaction by a 1st hardening process can be performed efficiently.

  The present invention also includes a pressure-sensitive adhesive laminate including a base material and the sheet-like pressure-sensitive adhesive layered on the base material.

The present invention is a method for producing a flexible member using the sheet-like pressure-sensitive adhesive,
A laminate preparation step for preparing a laminate in which a flexible substrate is fixed on a hard substrate via the sheet-like adhesive,
Also included is a method for manufacturing a flexible member, which includes a processing step of processing the flexible substrate to produce a flexible member, and a peeling step of peeling the flexible member from the sheet-like adhesive in this order. It is.

  In the manufacturing method of the present invention, since the flexible substrate is processed using the sheet-like pressure-sensitive adhesive, the generation of bubbles due to heat treatment during processing can be suppressed, which has been difficult in the past. A desired pattern can be easily and efficiently formed.

In the manufacturing method, the sheet-like pressure-sensitive adhesive contains a curable composition,
It is preferable that a first curing treatment is performed before or during the processing step to advance a part or all of the curing reaction of the curable composition.

  With this configuration, the degree of cure of the curable composition can be adjusted by the first curing treatment, and the hardness of the sheet-like pressure-sensitive adhesive can be set to a level required efficiently. Further, by using the heat treatment at the time of processing the flexible substrate as the first curing treatment, there is no need for a separate step for curing the curable composition, and the existing process can be effectively used. .

In the manufacturing method, after the laminate preparation step and before the processing step, or during the processing step, the first curing treatment is performed to advance a partial curing reaction of the curable composition,
After the processing step and before the peeling step, it is preferable to carry out a second curing treatment by irradiation with energy rays to advance the curing reaction of the remainder of the curable composition.

  By adopting such a two-stage curing process of the curable composition, the first curing treatment can be heated, so that the heat treatment during the processing of the flexible substrate can be used, and the second curing treatment can be performed. By using energy beam irradiation different from heating, the mechanism of the curing reaction between the two curing processes can be made different, and the degree of curing in the first curing process and the second curing process depends on the process design. It can be at an appropriate level.

  In the manufacturing method, by setting the glass transition point of the flexible substrate to 50 ° C. or higher, heat resistance against heat treatment during processing can be imparted, and a series of processing including pattern formation is efficiently performed. be able to.

  It is preferable that the thickness of the flexible substrate is 0.5 mm or less. The flexible substrate preferably includes plastic. Thereby, a thin flexible member can be produced suitably.

  The present invention also includes a film-like display device obtained by the method for producing the flexible member.

It is sectional drawing which shows typically the sheet-like adhesive which concerns on one Embodiment of this invention.

<Adhesive laminate>
As shown in FIG. 1, the pressure-sensitive adhesive laminate 10 includes a base material 1 and a sheet-like pressure-sensitive adhesive 2 laminated on the base material 1. Moreover, you may provide the separator 3 further on the exposed surface of the sheet-like adhesive 2 for the purpose of protection of the sheet-like adhesive 2 until actual use.

[Base material]
As the base material 1, a separator, a flexible substrate, a hard substrate, or the like can be used according to the processing process design of the flexible substrate.

(Separator)
When the substrate 1 is a separator, each of the separators 1 and 3 serves as a sheet-like pressure-sensitive adhesive support and also serves to protect the sheet-like pressure-sensitive adhesive until the pressure-sensitive adhesive laminate is put to practical use. Examples of the constituent material of the separator include low density polyethylene, linear polyethylene, medium density polyethylene, high density polyethylene, ultra low density polyethylene, random copolymer polypropylene, block copolymer polypropylene, homopolyprolene, polybutene, and polymethylpentene. Such as polyolefin, ethylene-vinyl acetate copolymer, ionomer resin, ethylene- (meth) acrylic acid copolymer, ethylene- (meth) acrylic acid ester (random, alternating) copolymer, ethylene-butene copolymer, Polyethylene such as ethylene-hexene copolymer, polyurethane, polyethylene terephthalate, polyethylene naphthalate, polycarbonate, polyimide, polyetheretherketone, polyimide, polyetherimide, polyamide, wholly aromatic Polyamide, polyphenyl sulphates id, aramid (paper), glass, glass cloth, fluorine resin, polyvinyl chloride, polyvinylidene chloride, cellulose resin, silicone resin, metal (foil), paper, and the like. The surface of the separator may be subjected to a peeling treatment such as a silicone treatment, a long-chain alkyl treatment, a fluorine treatment, a molybdenum sulfide treatment or the like in order to improve the peelability from the sheet-like pressure-sensitive adhesive. Also, it consists of fluorine-based polymers such as polytetrafluoroethylene, polychlorotrifluoroethylene, polyvinyl fluoride, polyvinylidene fluoride, tetrafluoroethylene / hexafluoropropylene copolymer, chlorotrifluoroethylene / vinylidene fluoride copolymer, etc. A low-adhesive substrate, a low-adhesive substrate made of a nonpolar polymer such as polyethylene or polypropylene, and the like are used.

  Although the thickness of a separator is not specifically limited, When handling property is considered, 10-200 micrometers is preferable and 20-100 micrometers is more preferable.

(Flexible substrate and hard substrate)
As a structure of the adhesion laminated body 10, a flexible substrate or a hard substrate can also be used as the base material 1 so that it can use for subsequent processing of a flexible substrate as it is. When a flexible substrate is used as the substrate 1, the pressure-sensitive adhesive laminate 10 has a structure in which the sheet-like pressure-sensitive adhesive 2 is laminated on the flexible substrate to be processed, and the separator 3 is further laminated as necessary. In the subsequent processing of the flexible substrate, the hard substrate is bonded to the sheet-like pressure-sensitive adhesive side after the separator is peeled off. On the other hand, when a hard substrate is used as the base material 1, the pressure-sensitive adhesive laminate 10 has a structure in which a sheet-like pressure-sensitive adhesive 2 is laminated on a hard substrate, and a separator 3 is further laminated as necessary. When the flexible substrate is processed, the flexible substrate is bonded to the sheet-like adhesive side after the separator is peeled off.

(Flexible substrate)
When a flexible substrate is used as the substrate 1, the material of the flexible substrate is not particularly limited as long as it is a material having heat resistance, dimensional stability, and surface smoothness, but the glass transition point (Tg) of the material is not limited. ) Is preferably 50 ° C. or higher, more preferably 100 ° C. or higher, and further preferably 200 ° C. or higher. Moreover, the material which does not have a glass transition point (Tg) can also be used suitably. Examples of such materials include polyesters such as polyethylene terephthalate and polyethylene naphthalate, polycarbonate, polyimide, polyetherimide, polyamide, polyamideimide, wholly aromatic polyamide, polyphenylsulfide, aramid (paper), glass, glass Examples thereof include cloth, fluororesin, silicone resin, metal (foil), paper, FRP, and ultrathin glass. In addition, if necessary, a film for improving the gas barrier property may be formed on these flexible substrates, and copper-clad laminates, membrane wiring boards, multilayer flexible circuit boards, etc. are adopted as materials for the flexible substrates. May be. Furthermore, a substrate subjected to via hole processing or the like can also be used.

  The thickness of the flexible substrate may be set according to the design of the device in which the processed flexible member is incorporated, but the upper limit of the thickness is preferably 0.5 mm or less, more preferably 0.15 mm or less. . Further, the lower limit of the thickness of the flexible substrate is preferably 0.01 mm or more, and more preferably 0.025 mm or more from the viewpoint of strength and durability.

(Hard substrate)
When a hard substrate is used as the base material 1, the material of the hard substrate is not particularly limited as long as the flexible substrate can be held via the sheet-like adhesive 2, but a material harder than the flexible substrate is preferable. Used, for example, silicon, glass, SUS plate, copper plate, acrylic plate and the like. The thickness of the hard substrate is not particularly limited as long as the flexible substrate can be stably held, but is preferably 0.1 to 10 mm, and is 0.4 mm or more (for example, 0.4 to 5.0 mm). More preferred.

[Sheet adhesive]
In the sheet-like pressure-sensitive adhesive 2, after the laminated body obtained by bonding the PEN film and the sheet-like pressure-sensitive adhesive is heated at 180 ° C. for 30 minutes, there are substantially bubbles at the interface between the PEN film and the sheet-like pressure-sensitive adhesive. It is not a sheet-like adhesive. In the said sheet-like adhesive, even after heating at 180 degreeC for 30 minute (s), a bubble does not exist substantially in the interface with the PEN film which is a counterpart material, but it is in the state with high adhesiveness. Thereby, desired processing can be performed without generating bubbles during heating in the processing step of the flexible substrate. Further, in the sheet-like pressure-sensitive adhesive 2, it is preferable that substantially no bubbles exist at the interface with the glass hard substrate after the same heat treatment is performed by bonding to the glass hard substrate. Thereby, it is possible to suppress air bubbles at both interfaces of the sheet-like pressure-sensitive adhesive 2 in the processing step, and it is possible to process a flexible substrate with more stability and high accuracy.

  The sheet-like pressure-sensitive adhesive 2 has a Young's modulus at 25 ° C. after being heated at 180 ° C. for 30 minutes, preferably 0.5 MPa or more, more preferably 1.0 MPa or more, and 3.0 MPa or more. More preferably. Further, the upper limit of the Young's modulus is preferably 500 MPa or less, more preferably 200 MPa or less, and further preferably 100 MPa or more, considering the retention of the subsequent flexible member. It is considered that bubbles at the interface between the sheet-like pressure-sensitive adhesive and the counterpart material are mainly caused by outgas such as moisture contained in each member. With the Young's modulus after a predetermined heat treatment of the sheet-like pressure-sensitive adhesive 2 within the above range, the sheet-like pressure-sensitive adhesive has an appropriate hardness in the processing step, so that the flexible substrate can be heated to the above-mentioned interface of the outgas. Can be prevented and the generation of bubbles can be efficiently suppressed.

  The sheet-like pressure-sensitive adhesive 2 may be a non-curable pressure-sensitive adhesive that does not exhibit curability itself, or may be a curable pressure-sensitive adhesive. In any type, the sheet-like pressure-sensitive adhesive 2 can substantially suppress the generation of bubbles at the interface with the mating material to be bonded, so that the flexible substrate can be processed accurately and efficiently. it can.

(Non-curable sheet adhesive)
As a constituent material of the non-curable sheet-like pressure-sensitive adhesive 2, for example, a commonly used pressure-sensitive pressure-sensitive adhesive can be used, and pressure-sensitive adhesives such as acrylic pressure-sensitive adhesives, rubber-based pressure-sensitive adhesives, and silicone-based pressure-sensitive adhesives. Can be used. In particular, when a sheet-like adhesive undergoes a thermal process in the manufacturing process of electronic devices and displays, an acrylic adhesive based on an acrylic polymer is used from the viewpoint of heat resistance, adherend contamination, and versatility. Agents are preferably used.

  Examples of the acrylic polymer include (meth) acrylic acid alkyl esters (for example, methyl ester, ethyl ester, propyl ester, isopropyl ester, butyl ester, isobutyl ester, s-butyl ester, t-butyl ester, pentyl ester, Isopentyl ester, hexyl ester, heptyl ester, octyl ester, 2-ethylhexyl ester, isooctyl ester, nonyl ester, isononyl ester, lauryl ester, stearyl ester, isostearyl ester, decyl ester, isodecyl ester, undecyl ester, Alkyl such as dodecyl ester, tridecyl ester, tetradecyl ester, hexadecyl ester, octadecyl ester, eicosyl ester Or a cycloalkyl ester of (meth) acrylic acid (for example, cyclopentyl ester, cyclohexyl ester, etc.) or 1 or 2 Examples thereof include acrylic polymers that use more than one species as monomer components. In addition, (meth) acrylic acid ester means acrylic acid ester and / or methacrylic acid ester, and (meth) of the present invention has the same meaning.

  The acrylic polymer includes units corresponding to other monomer components copolymerizable with the (meth) acrylic acid alkyl ester or cycloalkyl ester, as necessary, for the purpose of modifying cohesive strength, heat resistance, and the like. You may go out. Examples of such monomer components include carboxyl group-containing monomers such as acrylic acid, methacrylic acid, carboxyethyl (meth) acrylate, carboxypentyl (meth) acrylate, itaconic acid, maleic acid, fumaric acid, and crotonic acid; maleic anhydride Acid anhydride monomers such as itaconic anhydride; 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 6-hydroxyhexyl (meth) acrylate Hydroxyl group-containing monomers such as 8-hydroxyoctyl (meth) acrylate, 10-hydroxydecyl (meth) acrylate, 12-hydroxylauryl (meth) acrylate, (4-hydroxymethylcyclohexyl) methyl (meth) acrylate; The Sulfonic acid groups such as lensulfonic acid, allylsulfonic acid, 2- (meth) acrylamide-2-methylpropanesulfonic acid, (meth) acrylamidepropanesulfonic acid, sulfopropyl (meth) acrylate, (meth) acryloyloxynaphthalenesulfonic acid Containing monomers; Phosphoric acid group-containing monomers such as 2-hydroxyethylacryloyl phosphate; acrylamide, acrylonitrile, acryloylmorpholine, and the like. One or more of these copolymerizable monomer components can be used. The amount of these copolymerizable monomers used is preferably 40% by weight or less based on the total monomer components.

  Furthermore, since the acrylic polymer is crosslinked, a polyfunctional monomer or the like can be included as a monomer component for copolymerization as necessary. Examples of such polyfunctional monomers include hexanediol di (meth) acrylate, (poly) ethylene glycol di (meth) acrylate, (poly) propylene glycol di (meth) acrylate, neopentyl glycol di (meth) acrylate, Pentaerythritol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, dipentaerythritol hexa (meth) acrylate, epoxy (meth) acrylate, polyester (meth) acrylate, urethane (meth) Examples include acrylates. These polyfunctional monomers can also be used alone or in combination of two or more. The amount of the polyfunctional monomer used is preferably 30% by weight or less of the total monomer components from the viewpoint of adhesive properties and the like.

  The acrylic polymer can be obtained by subjecting a single monomer or a mixture of two or more monomers to polymerization. The polymerization can be performed by any method such as solution polymerization, emulsion polymerization, bulk polymerization, suspension polymerization, energy ray polymerization and the like. The sheet-like pressure-sensitive adhesive preferably has an appropriate cohesive force from the viewpoint of cutting the sheet-like pressure-sensitive adhesive, peeling the separator, peeling the flexible substrate, and the like. From this point, the weight average molecular weight of the acrylic polymer is preferably 300,000 or more, more preferably about 400,000 to 3 million. The weight average molecular weight is a polystyrene equivalent value using a standard polystyrene calibration curve by gel permeation chromatography (GPC).

(Curable sheet adhesive)
The curable composition contained in the curable sheet-like pressure-sensitive adhesive is a curable composition in which a curing reaction site for curing is introduced into the component system of the non-curable pressure-sensitive adhesive. Although the hardening process of a curable composition is not specifically limited, It is preferable to harden | cure by heating or energy beam irradiation. Such a curable composition is a composition that forms a cured region by being cured (polymerized or crosslinked) by heating or irradiation with energy rays. Whether to select heating or energy beam irradiation as the curing treatment may be determined according to the curing mechanism of the curable composition. The energy ray is not particularly limited, and examples thereof include ultraviolet rays, X-rays, electron beams, neutron rays, α rays, and β rays. However, it is necessary to keep the degree of curing so as not to lose the retainability of the flexible substrate. By the above configuration, or until the processing step of the flexible substrate in which outgas leaks to the interface between the sheet-like pressure-sensitive adhesive and the flexible substrate, preferably to the interface between the sheet-like pressure-sensitive adhesive and the hard substrate, or the processing During the process, the curable composition can be cured by heating or energy beam irradiation, so that the hardness of the sheet-like pressure-sensitive adhesive 2 can be adjusted to an appropriate range, and the outgas leakage can be at a higher level. It can be prevented efficiently.

  In the sheet-like pressure-sensitive adhesive 2, a part or all of the curing reaction of the curable composition may proceed by heating or energy ray irradiation as the first curing treatment. Thereby, the hardening degree of a curable composition can be adjusted by a 1st hardening process, and the hardness of the sheet adhesive 2 can be set to the level requested | required efficiently. In addition, when the first curing process is heating, it is not necessary to provide a separate process for curing the curable composition by replacing the first curing process with a heating process when processing the flexible substrate. Existing processes can be used effectively.

  Further, in the sheet-like pressure-sensitive adhesive 2, a part of the curable composition undergoes a curing reaction by the first curing process, and the curable composition is subjected to a second curing process performed after the first curing process. It is preferable that the remaining curing reaction proceeds. By curing such a curable composition in two stages, in the first curing process, the sheet-like pressure-sensitive adhesive 2 is adjusted to have an appropriate hardness, thereby preventing leakage of the outgas to the interface. It is possible to design a process in which the adhesive force of the sheet-like pressure-sensitive adhesive is reduced by the curing process and the flexible member is easily peeled off thereafter.

  As a 1st hardening process and a 2nd hardening process, it can select independently from a heating and energy beam irradiation, respectively. Examples of the combination of the first curing process and the second curing process include, for example, a combination of heating and energy beam irradiation, a combination of energy beam irradiation and heating, a combination of low temperature heating and high temperature heating, and a low dose energy beam irradiation. And a combination of irradiation with a high dose of energy rays. Especially, as a hardening process of a curable composition, it is preferable that said 1st hardening process is heating and said 2nd hardening process is energy ray irradiation. When performing process design to prevent leakage of outgas to the interface in the first curing process and to achieve easy peeling due to a decrease in the adhesive strength of the sheet adhesive in the second curing process, the first curing Heat treatment during processing of the flexible substrate can be used by making the treatment heat, and the curing reaction mechanism between the two hardening treatments by making the second curing treatment energy beam irradiation different from heating The degree of curing in the first curing process and the second curing process can be set to an appropriate level according to the process design.

  The curable composition does not ask | require the type of heat curable or energy beam irradiation curable. For each type, as an ingredient structure, an additive-type curable composition containing a curable component as a curing reaction site together with an adhesive component used in the above-described non-curable sheet-like adhesive, and the above-described non-curable sheet-like adhesive Forms such as an inherent curable composition in which a curable functional group as a curing reaction site is introduced into the pressure-sensitive adhesive component itself used, and combinations thereof can be adopted.

(Heat curable composition)
As the thermosetting composition cured by heating, a composition containing an external cross-linking agent for cross-linking the pressure-sensitive adhesive component to the pressure-sensitive adhesive component can be appropriately employed. In this case, the crosslinking reaction between the pressure-sensitive adhesive component into which a curable functional group capable of reacting with the crosslinking agent (hydroxyl group, carboxyl group, epoxy group, isocyanate group, etc.) has been introduced in advance and the above-mentioned crosslinking agent proceeds by heating, and is curable. Since the composition is cured, the curable composition is a combination of the additive type and the intrinsic type. Specific examples of the external crosslinking method include a method in which a so-called crosslinking agent such as a polyisocyanate compound, an epoxy compound, an aziridine compound, or a melamine crosslinking agent is added and reacted. A metal chelating agent such as an aluminum chelate compound can also be suitably used as the external cross-linking agent. When an external crosslinking agent is used for the acrylic pressure-sensitive adhesive, the blending amount thereof is appropriately determined depending on the balance with the base polymer to be crosslinked and further depending on the use application as the pressure-sensitive adhesive. In general, the blending amount of the external cross-linking agent is preferably 0.01 to 10 parts by weight and more preferably 0.1 to 5 parts by weight with respect to 100 parts by weight of the base polymer.

  As another heat-curable composition, a curable composition containing a radical generator that generates radicals upon heating and a pressure-sensitive adhesive component containing a carbon-carbon double bond can be suitably used. In this case, a carbon-carbon double bond as a curable functional group is introduced into the pressure-sensitive adhesive component, and the pressure-sensitive adhesive component itself contributes to the curing reaction, so that it becomes an inherently curable composition. When the first curing treatment of the sheet-like pressure-sensitive adhesive is heating, the cross-linking reaction between the carbon-carbon double bonds of the curable composition proceeds by this heating, so that the sheet-like pressure-sensitive adhesive is cured to a desired degree. be able to. In addition, the method of introduce | transducing a carbon-carbon double bond into an adhesive component is mentioned later.

  The internal heat-curable sheet-like pressure-sensitive adhesive 2 preferably contains 100 ppm or more, more preferably 200 ppm or more, and still more preferably 300 ppm or more of a radical generator that generates radicals upon heating. Thereby, when performing one part or all part hardening of a curable composition via a carbon-carbon double bond, the hardening reaction in a 1st hardening process can be performed efficiently. In addition, the upper limit of the content of the radical generator is preferably 2000 ppm or less, and more preferably 1000 ppm or less, from the viewpoint of the stability of the sheet-like pressure-sensitive adhesive. Such a radical generator may be added to a curable composition containing an acrylic polymer or other components, and is aged at a high temperature during the radical polymerization reaction of the constituent monomer of the acrylic polymer. Alternatively, the polymerization reaction may be stopped and the radical generator may be contained so as to remain in the system.

  Examples of radical generators that generate radicals by heating include organic peroxides and inorganic peroxides such as benzoyl peroxide (BPO) and potassium persulfate, and azo such as azobisisobutyronitrile (AIBN). Compounds and the like.

(Energy ray curable composition)
As the energy ray-curable composition that is cured by irradiation with energy rays, those having an energy ray-curable functional group such as a carbon-carbon double bond and exhibiting tackiness can be used without particular limitation. As the energy ray-curable composition, those whose adhesive strength is reduced by irradiation with energy rays (particularly ultraviolet rays) are desirable.

(Additive energy beam curable composition)
Examples of the energy beam curable composition include an additive type energy beam curable composition in which an energy beam curable monomer component or oligomer component is blended as a curable component in a general pressure-sensitive adhesive. Examples of general pressure-sensitive adhesives include those similar to pressure-sensitive pressure-sensitive adhesives such as the acrylic pressure-sensitive adhesive and rubber pressure-sensitive adhesive.

  Examples of the energy ray-curable monomer component to be blended include urethane (meth) acrylate oligomer, trimethylolpropane tri (meth) acrylate, tetramethylolmethanetetra (meth) acrylate, pentaerythritol tri (meth) acrylate, and pentaerythritol. Examples include tetra (meth) acrylate, dipentaerystol monohydroxypenta (meth) acrylate, dipentaerythritol hexa (meth) acrylate, 1,4-butanediol di (meth) acrylate, and the like. Examples of the energy ray curable oligomer component include various oligomers such as urethane, polyether, polyester, polycarbonate, and polybutadiene, and those having a molecular weight in the range of about 100 to 30,000 are suitable. The amount of the energy ray-curable monomer component or oligomer component is, for example, about 5 to 500 parts by weight, preferably about 10 to 150 parts by weight with respect to 100 parts by weight of the base polymer such as an acrylic polymer constituting the pressure-sensitive adhesive. is there.

(Internal energy ray curable composition)
In addition to the additive-type energy ray-curable adhesive described above, the energy ray-curable composition includes, as a base polymer of the adhesive component, a carbon-carbon double bond as a curable functional group on the polymer side. A preferred example is an internal energy ray-curable composition using a chain or a polymer having a chain or main chain terminal. The internal energy ray curable composition does not need to contain an oligomer component, which is a low molecular component, or does not contain many components, so that the oligomer component does not move through the adhesive over time and is stable. This is preferable because a sheet-like pressure-sensitive adhesive having a layered structure can be formed.

  The curable composition preferably contains a carbon-carbon double bond as a curable functional group as described above. In this case, it is preferable that the residual ratio of the carbon-carbon double bond after heating the sheet-like pressure-sensitive adhesive at 180 ° C. for 30 minutes is 60% or less. When the curable composition (that is, the energy ray curable composition) is cured through the carbon-carbon double bond as the curable functional group, the carbon-carbon double bond remains after the predetermined heat treatment. When cured such that the rate is 60% or less, the hardness of the sheet-like pressure-sensitive adhesive can be adjusted to an appropriate level, and the generation of bubbles can be suppressed.

  As the base polymer having a carbon-carbon double bond, those having a carbon-carbon double bond and having adhesiveness can be used without particular limitation. As such a base polymer, an acrylic polymer having a basic skeleton is preferable. Examples of the basic skeleton of the acrylic polymer include the acrylic polymers exemplified above.

  The method for introducing the carbon-carbon double bond into the acrylic polymer is not particularly limited, and various methods can be adopted. However, when the carbon-carbon double bond is introduced into the polymer side chain, the molecular design is easy. For example, after a monomer having a functional group is copolymerized in advance with an acrylic polymer, a compound having a functional group capable of reacting with the functional group and a carbon-carbon double bond is cured with energy rays of the carbon-carbon double bond. Examples of the method include condensation or addition reaction while maintaining the properties.

  Examples of combinations of these functional groups include carboxylic acid groups and epoxy groups, carboxylic acid groups and aziridyl groups, hydroxyl groups and isocyanate groups. Among these combinations of functional groups, a combination of a hydroxyl group and an isocyanate group is preferable because of easy tracking of the reaction. In addition, the functional group may be on either side of the acrylic polymer and the compound as long as the acrylic polymer having the carbon-carbon double bond is generated by the combination of these functional groups. In the preferable combination, it is preferable that the acrylic polymer has a hydroxyl group and the compound has an isocyanate group. In this case, examples of the isocyanate compound having a carbon-carbon double bond include methacryloyl isocyanate, 2-methacryloyloxyethyl isocyanate, m-isopropenyl-α, α-dimethylbenzyl isocyanate, and the like. Further, as the acrylic polymer, those obtained by copolymerizing the above-exemplified hydroxy group-containing monomers, ether compounds of 2-hydroxyethyl vinyl ether, 4-hydroxybutyl vinyl ether, diethylene glycol monovinyl ether, or the like are used.

  In the intrinsic energy ray-curable composition, the base polymer (particularly acrylic polymer) having the carbon-carbon double bond can be used alone, but the energy ray-curable composition is not degraded to the extent that the properties are deteriorated. A monomer component and an oligomer component can also be mix | blended. In this case, the energy ray-curable oligomer component or the like is usually in the range of 200 parts by weight or less, preferably 0 to 100 parts by weight, based on 100 parts by weight of the base polymer.

  The energy ray curable composition contains a photopolymerization initiator when cured by ultraviolet rays or the like. Examples of the photopolymerization initiator include 4- (2-hydroxyethoxy) phenyl (2-hydroxy-2-propyl) ketone, α-hydroxy-α, α′-dimethylacetophenone, 2-methyl-2-hydroxypropio Α-ketol compounds such as phenone and 1-hydroxycyclohexyl phenyl ketone; methoxyacetophenone, 2,2-dimethoxy-2-phenylacetophenone, 2,2-diethoxyacetophenone, 2-methyl-1- [4- ( Acetophenone compounds such as methylthio) -phenyl] -2-morpholinopropane-1; benzoin ether compounds such as benzoin ethyl ether, benzoin isopropyl ether and anisoin methyl ether; ketal compounds such as benzyldimethyl ketal; 2-naphthalenesulfo D Aromatic sulfonyl chloride compounds such as luchloride; 1,2-octanedione, 1- [4- (phenylthio)-, 2- (0-benzoyloxime)], 1-phenyl-1,2-propanedione-2- Photoactive oxime compounds such as (O-ethoxycarbonyl) oxime; benzophenone compounds such as benzophenone, benzoylbenzoic acid, 3,3′-dimethyl-4-methoxybenzophenone; thioxanthone, 2-chlorothioxanthone, 2-methylthio Thioxanthone compounds such as xanthone, 2,4-dimethylthioxanthone, isopropylthioxanthone, 2,4-dichlorothioxanthone, 2,4-diethylthioxanthone, 2,4-diisopropylthioxanthone; camphor Quinone; Halogenated ketone; Acylphosphino Sid; and acyl phospholipase diisocyanate, and the like. The compounding quantity of a photoinitiator is 0.1-10 weight part with respect to 100 weight part of base polymers, such as an acryl-type polymer which comprises an adhesive, Preferably it is about 0.5-5 weight part.

(Other ingredients)
Furthermore, in addition to the above-described components, additives such as various conventionally known tackifiers, plasticizers, pigments, fillers and anti-aging agents may be used in the sheet-like pressure-sensitive adhesive as necessary.

  The thickness of the sheet-like pressure-sensitive adhesive can be appropriately determined, but is preferably 1 to 500 μm, more preferably 5 to 300 μm, and still more preferably 20 to 50 μm, particularly from the viewpoint of workability such as cutting.

  In addition, when using an energy ray-curable adhesive, depending on the use conditions, composition, and compounding, it may be pre-irradiated with energy rays and bonded in a state in which the adhesive strength is reduced before bonding with the counterpart material. Is possible.

[Method for producing adhesive laminate]
The separator 1 can be formed by a conventionally known film forming method. Examples of the film forming method include a calendar film forming method, a casting method in an organic solvent, an inflation extrusion method in a closed system, a T-die extrusion method, a co-extrusion method, and a dry lamination method. Then, a separator can be produced by performing a known release treatment on the film formed.

  Next, a pressure-sensitive adhesive composition solution for forming a sheet-shaped pressure-sensitive adhesive is prepared. In the adhesive composition solution, a resin, an additive, or the like as described in the section of the sheet-like adhesive is blended. After the prepared pressure-sensitive adhesive composition solution is applied on the separator 1 to form a coating film, the coating film is dried under predetermined conditions (heat-crosslinked as necessary) to form a sheet-shaped pressure-sensitive adhesive 2 To do. It does not specifically limit as a coating method, For example, roll coating, screen coating, gravure coating, etc. are mentioned. As drying conditions, for example, the drying temperature is 50 to 150 ° C. and the drying time is 0.5 to 5 minutes. Thereafter, the sheet-like pressure-sensitive adhesive 2 is bonded to the separator 3 together with the separator 1. Thereby, the adhesion laminated body provided with the sheet-like adhesive 2 pinched | interposed between the separators 1 and 3 is produced.

  The above shows an example in which a separator is used as the base material. However, when a flexible substrate or a hard substrate is used as the base material, the target substrate is prepared in the same manner as the separator, or a commercially available substrate is preferably used. Can be.

<Method for producing flexible member>
The manufacturing method of the flexible member of this embodiment includes a laminate preparation step of preparing a laminate in which a flexible substrate is fixed on a hard substrate via the sheet-like adhesive, and processing the flexible substrate. Then, a processing step for producing a flexible member and a peeling step for peeling the flexible member from the sheet-like adhesive are included in this order.

[Laminated body preparation process]
The preparation procedure of a laminated body can be changed according to the structure of an adhesion laminated body. A description will be given based on a form in which both sides of a sheet-like pressure-sensitive adhesive generally employed as an adhesive laminate are sandwiched between separators. In this case, one separator is peeled off, and the exposed sheet-like adhesive and the flexible substrate are bonded together. Next, a predetermined laminate can be prepared by peeling off the other separator and bonding the exposed sheet-like pressure-sensitive adhesive and the hard substrate together. In contrast to this procedure, a procedure in which a hard substrate is first bonded and then a flexible substrate is bonded can also be employed.

  When the pressure-sensitive adhesive laminate has a form in which the sheet-like pressure-sensitive adhesive and the flexible substrate are laminated in this order on the separator, after the separator is peeled off, the exposed sheet-like pressure-sensitive adhesive and the hard substrate are bonded together. Thus, a predetermined laminate can be prepared.

  Further, when the pressure-sensitive adhesive laminate has a form in which the sheet-like pressure-sensitive adhesive and the separator are laminated in this order on the hard substrate, the exposed sheet-like pressure-sensitive adhesive and the flexible substrate are pasted after the separation of the separator. By combining them, a predetermined laminate can be prepared.

  As a separator, a flexible substrate, and a hard substrate, what was demonstrated in the term of the board | substrate of an adhesion laminated body can be employ | adopted suitably.

  The members may be bonded to each other as long as they can be brought into close contact with each other. For example, the members can be bonded using a roller, a spatula, a press machine, or the like.

[Processing process]
The processing for the flexible substrate is not particularly limited, and a conventionally known process can be adopted depending on the device design to which the processed flexible member is applied, but a typical example is pattern formation. . Patterns include flexible substrates, flexible circuit boards (FPCs) for which they are used, base substrates for organic EL panels, electronic paper, LCDs, display circuits using organic EL as display units, color filters, Includes a circuit, a thin film, an element, and the like formed on the flexible substrate that are required for use in applications such as a touch panel circuit board and a solar cell film forming process. Any pattern may be used as long as it is necessary for the above application, and the shape and material of the pattern can be appropriately selected.

  When the flexible member is a member on which a circuit board such as a TFT (driving circuit) or a color filter is formed, the circuit board can be manufactured through a known photolithography process. As a typical photolithography process, procedures such as formation of an organic or inorganic thin film, application of a resist composition, baking of a resist coating, exposure, etching of the resist coating, etching of the thin film, removal of the resist film are repeated. Thus, a desired pattern circuit can be formed.

  In the processing step, the sheet-like adhesive is heated in the formation of a thin film, baking of the resist film, cleaning after etching, and drying. Conventionally, due to such heat treatment, bubbles may be generated at the interface between the temporary fixing material and the flexible substrate or the interface between the temporary fixing material and the hard substrate, and a desired pattern may not be formed. . In the present invention, since a sheet-like pressure-sensitive adhesive that can substantially suppress the generation of bubbles at the interface is used, a desired pattern can be formed.

  When the sheet-like pressure-sensitive adhesive contains a curable composition, the sheet-like pressure-sensitive adhesive can be adjusted to an appropriate hardness without changing the existing process by using the heat treatment as the first curing process. Leakage of outgas from each member to the interface can be efficiently suppressed. The heat treatment conditions are conditions in accordance with the pattern formation procedure (formation of a thin film, baking of a resist coating film, drying after etching, etc.), but generally 50 in consideration of the heat resistance of the flexible substrate. What is necessary is just to heat at -230 degreeC for 1-360 minutes. In the case where the heat treatment is performed a plurality of times, the above conditions can be adopted as the heat treatment per one time.

  In the case where the sheet-like pressure-sensitive adhesive contains an energy ray-curable composition and energy ray irradiation is adopted as the first curing treatment, it is preferably performed at least before the heat treatment in the processing step. Thereby, the hardness of a sheet-like adhesive can be adjusted to a suitable level before heat processing, and the leakage of outgas to this interface can be suppressed. In this case, the sheet-like pressure-sensitive adhesive 2 preferably contains 100 ppm or more of a radical generator that generates radicals upon energy irradiation, more preferably 1000 ppm or more, and even more preferably 10000 ppm or more. Thereby, when performing one part or all part hardening of a curable composition via a carbon-carbon double bond, the hardening reaction in a 1st hardening process can be performed efficiently. In addition, the upper limit of the content of the radical generator is preferably 100000 ppm or less and more preferably 50000 ppm or less from the viewpoint of the stability of the sheet-like pressure-sensitive adhesive. As the radical generator that generates radicals by energy irradiation, the above photopolymerization initiator can be suitably used.

  The flexible circuit board can be a flexible circuit board such as a single-sided circuit, a double-sided circuit, or a multilayer circuit. In addition to forming a circuit, an element or the like can be mounted. In order to form a circuit on both sides of a flexible substrate, the circuit is formed on one side, and then the circuit forming surface is fixed to a rigid substrate via an adhesive and a circuit is formed on the other side. it can.

  For example, when an organic transistor is formed on a flexible substrate, the material is not particularly limited, and a low molecular organic semiconductor material, a high molecular organic semiconductor material, or an organic / inorganic hybrid semiconductor material can be used. As the gate insulating material, an organic polymer material or an inorganic material can be used.

  As a means for forming the organic transistor, there is a transfer method or the like, and the electrode and the wiring can be formed by drawing directly on the film. As these materials, a metal nano paste or ink containing metal nanoparticles such as silver, or a paste or ink containing metal oxide nanoparticles can be employed. Alternatively, a conductive polymer solution or the like may be employed. As a method for drawing such transistors and electrodes / wirings, an inkjet method, a screen printing method, a gravure printing, a flexographic printing, and a nanoprinting technique can be employed. Further, a TFT circuit or the like may be formed on the film by transfer.

  It is possible to form a layer necessary for forming a display layer such as a liquid crystal display or an organic EL display on the flexible circuit board manufactured in this way, and a layer structure corresponding to each display and It is processed to become.

[Peeling process]
The flexible member obtained by processing the flexible substrate is peeled from the sheet-like adhesive by an appropriate means. When the sheet-like pressure-sensitive adhesive contains a curable composition that is cured by heating or energy ray irradiation, only a part of the curing reaction of the curable composition by the heat treatment in the processing step is allowed to proceed, and the heating or energy in the peeling step. The curing reaction of the remainder of the curable composition is advanced by irradiation with rays (for example, ultraviolet rays). Thereby, the adhesive force of a sheet-like adhesive can be reduced and peeling can be performed easily. Irradiation conditions such as the heating temperature, the heating time, the irradiation intensity of energy beam irradiation, and the irradiation time are not particularly limited and can be appropriately set as necessary.

  Hereinafter, preferred embodiments of the present invention will be described in detail by way of example. However, the materials, blending amounts, and the like described in the examples are not intended to limit the scope of the present invention only to those unless otherwise specified.

  First, a separator obtained by treating a PET film (trade name “Lumirror S27”, manufactured by Toray Industries, Inc.) with a silicone release agent was prepared as a base separator. Moreover, the separator which processed with the silicone mold release agent was prepared for PET film (Brand name "Lumirror S27", Toray Industries, Inc. make) as a cover separator. These separators were used in each example and comparative example.

[Example 1]
100 parts by weight of 2-ethylhexyl acrylate (2-EHA) and 4 parts by weight of acrylic acid (AA) are charged into a reaction vessel equipped with a cooling pipe, a nitrogen introduction pipe, a thermometer and a stirrer. On the other hand, 0.2 part by weight of 2,2 azobisisobutyronitrile (AIBN) and 155.3 parts by weight of ethyl acetate were added, and polymerization treatment was performed at 60 ± 2 ° C. for 4-5 hours in a nitrogen stream, 70 ± 2 Aging treatment was carried out at 4 ° C. for 4-5 hours to obtain an acrylic polymer.

  Next, 5 parts by weight of an epoxy-based crosslinking agent (T / C) (trade name “Tetrad C”, manufactured by Mitsubishi Gas Chemical Co., Ltd.) was added to 100 parts by weight of the acrylic polymer to prepare an adhesive solution. .

  The pressure-sensitive adhesive solution prepared above was applied onto the surface of the base separator that had been subjected to the silicone release treatment, and was heat-dried at 120 ° C. for 3 minutes to form a sheet-shaped pressure-sensitive adhesive having a thickness of 20 μm. Subsequently, the surface of the sheet-like pressure-sensitive adhesive that had been subjected to the silicone release treatment of the cover separator was bonded together to prepare a pressure-sensitive adhesive laminate.

[Example 2]
In a reaction vessel equipped with a cooling tube, a nitrogen introduction tube, a thermometer, and a stirring device, 75 parts by weight of 2-ethylhexyl acrylate (2-EHA), 25 parts by weight of acryloylmorpholine (ACMO), 2.4 parts of acrylic acid (AA) Parts by weight, 0.1 part by weight of 2-hydroxyethyl acrylate (HEA) is added, 0.2 part by weight of 2,2 azobisisobutyronitrile (AIBN) and 188. 75 parts by weight was added and polymerized in a nitrogen stream at 57 ± 3 ° C. for 6-7 hours to obtain an acrylic polymer.

  Next, 3 parts by weight of an epoxy crosslinking agent (T / C) (trade name “Tetrad C”, manufactured by Mitsubishi Gas Chemical Co., Ltd.) was added to 100 parts by weight of the acrylic polymer to prepare a pressure-sensitive adhesive solution. .

  The pressure-sensitive adhesive solution prepared above was applied onto the surface of the base separator that had been subjected to the silicone release treatment, and was heat-dried at 120 ° C. for 3 minutes to form a sheet-shaped pressure-sensitive adhesive having a thickness of 20 μm. Subsequently, the surface of the sheet-like pressure-sensitive adhesive that had been subjected to the silicone release treatment of the cover separator was bonded together to prepare a pressure-sensitive adhesive laminate.

[Example 3]
In a reaction vessel equipped with a cooling tube, a nitrogen introduction tube, a thermometer and a stirring device, 100 parts by weight of 2-ethylhexyl acrylate (2-EHA), 2.4 parts by weight of acryloylmorpholine (ACMO), 2-hydroxyethyl acrylate 14 parts by weight of (HEA) is added, 0.2 part by weight of benzoyl peroxide (BPO) and 66.7 parts by weight of toluene are added to 100 parts by weight of the monomer, and 6 ° C. at 60 ± 2 ° C. in a nitrogen stream. A time polymerization treatment was carried out to obtain an acrylic polymer A.

  To this acrylic polymer A, 0.72 equivalent of 2-methacryloyloxyethyl isocyanate (MOI) is added to 1 equivalent of hydroxyl group of 2-hydroxyethyl acrylate (HEA) of the acrylic polymer A, and 50% in an air stream. An addition reaction treatment was performed at ± 1 ° C. for 6 hours to obtain an acrylic polymer A ′.

  Next, 0.1 part by weight of an isocyanate-based crosslinking agent (C / L) (trade name “Coronate L”, manufactured by Nippon Polyurethane Industry Co., Ltd.) and 100% by weight of the acrylic polymer A ′ and a photopolymerization initiator. (Irg127) (trade name “IRGACURE127”, manufactured by BASF) 2 parts by weight was added to prepare an adhesive solution.

  The pressure-sensitive adhesive solution prepared above was applied onto the surface of the base separator that had been subjected to silicone treatment, and dried by heating at 120 ° C. for 3 minutes to form a sheet-shaped pressure-sensitive adhesive having a thickness of 20 μm. Subsequently, the surface of the sheet-like pressure-sensitive adhesive that had been subjected to the silicone release treatment of the cover separator was bonded together to prepare a pressure-sensitive adhesive laminate.

[Example 4]
In a reaction vessel equipped with a cooling tube, a nitrogen introduction tube, a thermometer and a stirrer, 100 parts by weight of 2-ethylhexyl acrylate (2-EHA), 0.4 parts by weight of acrylic acid (AA), 2-hydroxyethyl acrylate (HEA) 12.7 parts by weight was charged, 0.2 parts by weight of benzoyl peroxide (BPO) and 66.7 parts by weight of toluene were added to 100 parts by weight of the monomer, and the temperature was adjusted to 61 ± 2 ° C. in a nitrogen stream. For 6 hours to obtain an acrylic polymer A.

  To this acrylic polymer A, 0.8 equivalent of 2-methacryloyloxyethyl isocyanate (MOI) is added to 1 equivalent of the hydroxyl group of 2-hydroxyethyl acrylate (HEA) of the acrylic polymer A, and 50 in an air stream. An addition reaction treatment was performed at ± 1 ° C. for 8 hours to obtain an acrylic polymer A ′.

  Next, 3 parts by weight of aluminum tris (acetylacetonate) (Alh) (trade name “aluminum chelate A (W)”, manufactured by Kawaken Fine Chemicals Co., Ltd.) and 100 parts by weight of acrylic polymer A ′ 2 parts by weight of a polymerization initiator (Irg127) (trade name “IRGACURE127”, manufactured by BASF) was added to prepare an adhesive solution.

  The pressure-sensitive adhesive solution prepared above was applied onto the surface of the base separator that had been subjected to silicone treatment, and dried by heating at 120 ° C. for 3 minutes to form a sheet-shaped pressure-sensitive adhesive having a thickness of 20 μm. Subsequently, the surface of the sheet-like pressure-sensitive adhesive that had been subjected to the silicone release treatment of the cover separator was bonded together to prepare a pressure-sensitive adhesive laminate.

[Example 5]
In a reaction vessel equipped with a cooling tube, a nitrogen introduction tube, a thermometer and a stirrer, 100 parts by weight of 2-ethylhexyl acrylate (2-EHA), 0.5 parts by weight of acrylic acid (AA), 40 parts by weight of isononyl acrylate In addition, 18 parts by weight of 2-hydroxyethyl acrylate (HEA) was added, 0.2 parts by weight of benzoyl peroxide (BPO) and 66.7 parts by weight of toluene were added to 100 parts by weight of the monomer, and in a nitrogen stream. Polymerization was performed at 61 ± 2 ° C. for 6 hours to obtain an acrylic polymer A.

  To this acrylic polymer A, 0.8 equivalent of 2-methacryloyloxyethyl isocyanate (MOI) is added to 1 equivalent of the hydroxyl group of 2-hydroxyethyl acrylate (HEA) of the acrylic polymer A, and 50 in an air stream. An addition reaction treatment was performed at ± 1 ° C. for 8 hours to obtain an acrylic polymer A ′.

  Next, 3 parts by weight of aluminum tris (acetylacetonate) (Alh) (trade name “aluminum chelate A (W)”, manufactured by Kawaken Fine Chemicals Co., Ltd.) and 100 parts by weight of acrylic polymer A ′ 2 parts by weight of a polymerization initiator (Irg127) (trade name “IRGACURE127”, manufactured by BASF) was added to prepare an adhesive solution.

  The pressure-sensitive adhesive solution prepared above was applied onto the surface of the base separator that had been subjected to silicone treatment, and dried by heating at 120 ° C. for 3 minutes to form a sheet-shaped pressure-sensitive adhesive having a thickness of 20 μm. Subsequently, the surface of the sheet-like pressure-sensitive adhesive that had been subjected to the silicone release treatment of the cover separator was bonded together to prepare a pressure-sensitive adhesive laminate.

[Example 6]
In a reaction vessel equipped with a cooling tube, a nitrogen introduction tube, a thermometer and a stirrer, 100 parts by weight of 2-ethylhexyl acrylate (2-EHA), 0.5 parts by weight of acrylic acid (AA), lauryl acrylate (LA) 40 parts by weight, 2-hydroxyethyl acrylate (HEA) 16 parts by weight, benzoyl peroxide (BPO) 0.2 parts by weight and toluene 66.7 parts by weight with respect to 100 parts by weight of monomer, nitrogen Polymerization was performed in an air stream at 61 ± 2 ° C. for 6 hours to obtain an acrylic polymer A.

  To this acrylic polymer A, 0.8 equivalent of 2-methacryloyloxyethyl isocyanate (MOI) is added to 1 equivalent of the hydroxyl group of 2-hydroxyethyl acrylate (HEA) of the acrylic polymer A, and 50 in an air stream. An addition reaction treatment was performed at ± 1 ° C. for 8 hours to obtain an acrylic polymer A ′.

  Next, 3 parts by weight of aluminum tris (acetylacetonate) (Alh) (trade name “aluminum chelate A (W)”, manufactured by Kawaken Fine Chemicals Co., Ltd.) and 100 parts by weight of acrylic polymer A ′ 2 parts by weight of a polymerization initiator (Irg127) (trade name “IRGACURE127”, manufactured by BASF) was added to prepare an adhesive solution.

  The pressure-sensitive adhesive solution prepared above was applied onto the surface of the base separator that had been subjected to silicone treatment, and dried by heating at 120 ° C. for 3 minutes to form a sheet-shaped pressure-sensitive adhesive having a thickness of 20 μm. Subsequently, the surface of the sheet-like pressure-sensitive adhesive that had been subjected to the silicone release treatment of the cover separator was bonded together to prepare a pressure-sensitive adhesive laminate.

[Comparative Example 1]
100 parts by weight of 2-ethylhexyl acrylate (2-EHA) and 4 parts by weight of acrylic acid (AA) are charged into a reaction vessel equipped with a cooling pipe, a nitrogen introduction pipe, a thermometer and a stirrer. On the other hand, 0.2 part by weight of 2,2 azobisisobutyronitrile (AIBN) and 155.3 parts by weight of ethyl acetate were added, and polymerization treatment was performed at 60 ± 2 ° C. for 4-5 hours in a nitrogen stream, 70 ± 2 Aging treatment was carried out at 4 ° C. for 4-5 hours to obtain an acrylic polymer.

  Next, 1 part by weight of an epoxy-based crosslinking agent (T / C) (trade name “Tetrad C”, manufactured by Mitsubishi Gas Chemical Co., Ltd.) was added to 100 parts by weight of the acrylic polymer to prepare an adhesive solution. .

  The pressure-sensitive adhesive solution prepared above was applied onto the surface of the base separator that had been subjected to the silicone release treatment, and was heat-dried at 120 ° C. for 3 minutes to form a sheet-shaped pressure-sensitive adhesive having a thickness of 20 μm. Subsequently, the surface of the sheet-like pressure-sensitive adhesive that had been subjected to the silicone release treatment of the cover separator was bonded together to prepare a pressure-sensitive adhesive laminate.

[Comparative Example 2]
In a reaction vessel equipped with a cooling tube, a nitrogen introduction tube, a thermometer, and a stirring device, 75 parts by weight of 2-ethylhexyl acrylate (2-EHA), 25 parts by weight of acryloylmorpholine (ACMO), 2.4 parts of acrylic acid (AA) Parts by weight, 0.1 part by weight of 2-hydroxyethyl acrylate (HEA) is added, 0.2 part by weight of 2,2 azobisisobutyronitrile (AIBN) and 188. 75 parts by weight was added and polymerized in a nitrogen stream at 57 ± 3 ° C. for 6-7 hours to obtain an acrylic polymer.

  The pressure-sensitive adhesive solution prepared above was applied onto the surface of the base separator that had been subjected to the silicone release treatment, and was heat-dried at 120 ° C. for 3 minutes to form a sheet-shaped pressure-sensitive adhesive having a thickness of 20 μm. Subsequently, the surface of the sheet-like pressure-sensitive adhesive that had been subjected to the silicone release treatment of the cover separator was bonded together to prepare a pressure-sensitive adhesive laminate.

[Comparative Example 3]
In a reaction vessel equipped with a cooling pipe, a nitrogen introduction pipe, a thermometer and a stirring device, 100 parts by weight of methoxyethyl acrylate (MEA), 27 parts by weight of acryloylmorpholine (ACMO), 22 parts by weight of 2-hydroxyethyl acrylate (HEA) Benzoyl peroxide (BPO) 0.2 parts by weight and ethyl acetate 340 parts by weight with respect to 100 parts by weight of the monomer, and polymerization treatment at 62 ± 1 ° C. for 6-7 hours in a nitrogen stream. Aging treatment was carried out at 72 ± 2 ° C. for 1.5-2 hours to obtain an acrylic polymer A.

  To this acrylic polymer A, 0.8 equivalent of 2-methacryloyloxyethyl isocyanate (MOI) is added to 1 equivalent of the hydroxyl group of 2-hydroxyethyl acrylate (HEA) of the acrylic polymer A, and 50 in an air stream. The addition reaction treatment was carried out at ± 1 ° C. for 12-15 hours to obtain acrylic polymer A ′.

  Next, with respect to 100 parts by weight of the acrylic polymer A ′, 0.02 parts by weight of an isocyanate-based crosslinking agent (C / L) (trade name “Coronate L”, manufactured by Nippon Polyurethane Industry Co., Ltd.), and a photopolymerization initiator (Irg127) (trade name “IRGACURE127”, manufactured by BASF) 2 parts by weight was added to prepare an adhesive solution.

  The pressure-sensitive adhesive solution prepared above was applied onto the surface of the base separator that had been subjected to silicone treatment, and dried by heating at 120 ° C. for 3 minutes to form a sheet-shaped pressure-sensitive adhesive having a thickness of 20 μm. Subsequently, the surface of the sheet-like pressure-sensitive adhesive that had been subjected to the silicone release treatment of the cover separator was bonded together to prepare a pressure-sensitive adhesive laminate.

[Comparative Example 4]
In a reaction vessel equipped with a cooling pipe, a nitrogen introduction pipe, a thermometer and a stirrer, 100 parts by weight of 2-ethylhexyl acrylate (2-EHA), 25 parts by weight of acryloylmorpholine (ACMO), 2-hydroxyethyl acrylate (HEA) ) 18 parts by weight, 0.2 parts by weight of benzoyl peroxide (BPO) and 68 parts by weight of toluene are added to 100 parts by weight of the monomer, and polymerization is performed at 60 ± 3 ° C. for 8-11 hours in a nitrogen stream. The acrylic polymer A was obtained by processing.

  To this acrylic polymer A, 0.5 equivalent of 2-methacryloyloxyethyl isocyanate (MOI) is added to 1 equivalent of a hydroxyl group of 2-hydroxyethyl acrylate (HEA) of the acrylic polymer A, and 50 in an air stream. The addition reaction treatment was performed at ± 3 ° C. for 14-17 hours to obtain an acrylic polymer A ′.

  Next, 0.1 part by weight of an isocyanate-based crosslinking agent (C / L) (trade name “Coronate L”, manufactured by Nippon Polyurethane Industry Co., Ltd.) and 100% by weight of the acrylic polymer A ′ and a photopolymerization initiator. (Irg127) (trade name “IRGACURE127”, manufactured by BASF) 2 parts by weight was added to prepare an adhesive solution.

  The pressure-sensitive adhesive solution prepared above was applied onto the surface of the base separator that had been subjected to silicone treatment, and dried by heating at 120 ° C. for 3 minutes to form a sheet-shaped pressure-sensitive adhesive having a thickness of 20 μm. Subsequently, the surface of the sheet-like pressure-sensitive adhesive that had been subjected to the silicone release treatment of the cover separator was bonded together to prepare a pressure-sensitive adhesive laminate.

(Evaluation of presence or absence of bubbles during heating at 180 ° C)
The base separator is peeled off from the adhesive laminates of Examples and Comparative Examples, and the exposed sheet-like adhesive and polyethylene naphthalate (PEN) film (trade name “Teonex Q51”, manufactured by Teijin Ltd.) are pasted with a hand roller. Combined. Next, the cover separator is peeled off, and the exposed sheet-like pressure-sensitive adhesive and a glass hard substrate (length 80 mm × width 80 mm × thickness 0.55 mm, trade name “blue plate edge polished product”, manufactured by Matsunami Glass Industrial Co., Ltd. ) To form a laminated body, and this laminated body was cut into a size of 80 mm length × 80 mm width to produce a laminated body for evaluation. The laminate for evaluation was heated at 180 ° C. for 30 minutes and then allowed to stand for 30 minutes or more in an atmosphere at 25 ° C., and then the presence or absence of bubbles having a maximum diameter of 500 μm or more was confirmed by an optical microscope. The case where bubbles were not confirmed was evaluated as “◯”, and the case where bubbles were generated was evaluated as “x”. The results are shown in Table 1.

(Measurement of residual ratio of carbon-carbon double bond after heating at 180 ° C.)
The base separator was peeled off from the pressure-sensitive adhesive laminates of the examples and comparative examples, and the exposed sheet-like pressure-sensitive adhesive surface was subjected to infrared absorption using an FT-IR measuring device (device name “Spectrum One FT-IR Spectrometer”, manufactured by PerkinElmer). The spectrum measurement (ATR method, 1 reflection, 64 integrations, Ge crystal) was performed. From the obtained absorption spectrum, the ratio X of the absorbance at 810 cm ⁻¹ (derived from C═C) to the absorbance at 1720 cm ⁻¹ (C═O stretching) was determined. Using the sample, the evaluation laminate for bubble evaluation was prepared and heated at 180 ° C. for 30 minutes. After heating, the PEN film was peeled off from the sample that was allowed to stand for 30 minutes or more in an atmosphere at 25 ° C., and the surface of the exposed sheet-like pressure-sensitive adhesive was measured in the same manner as described above. From the obtained absorption spectrum, the ratio Y of the absorbance at 810 cm ⁻¹ (derived from C═C) to the absorbance at 1720 cm ⁻¹ (C═O stretching) was determined. The value obtained by (ratio Y / ratio X) × 100 [%] was defined as the residual ratio of carbon-carbon double bonds. The results are shown in Table 1.

(Measurement of Young's modulus after heating at 180 ° C)
The pressure-sensitive adhesive laminates obtained in the examples and comparative examples were sandwiched between two 10 mm thick hard substrates and heated at 180 ° C. for 30 minutes, and then allowed to stand at 25 ° C. for 30 minutes or more. It peeled and the sheet-like adhesive was exposed. The sheet-like pressure-sensitive adhesive was wound up into a roll having a height of 50 mm by a human hand to obtain a measurement sample. A measurement sample is set on a tensile measurement jig, and a tensile tester (device name “TENSILON RTC-1150A”, manufactured by ORIENTEC Co., Ltd.) is used at a distance between chucks: 10 mm, a tensile speed: 50 mm / min, and 25 ° C. The stress-strain curve was measured and the Young's modulus was determined from the linear region where the strain was between 0-10%. The results are shown in Table 1.

(Measurement of benzoyl peroxide (BPO) content)
About 0.1 g of a sample was collected from the sheet-like pressure-sensitive adhesives produced in Examples and Comparative Examples, and ethyl acetate was added and shaken overnight or longer. Thereafter, 10 ml of acetonitrile was added and the mixture was further shaken for 3 hours or more. The obtained solution was filtered through a 0.2 μm membrane filter and subjected to HPLC measurement under the following conditions to measure the amount of benzoyl peroxide. The results are shown in Table 1.
<Analyzer and measurement conditions>
Made by Dionex, UltimateMate 3000
Column: ZORBAX Eclipse Plus (3.0 mmφ × 50 mm, 1.8 μm)
Eluent: Distilled water / acetonitrile reverse phase gradient condition Flow rate: 0.8 ml / min
Detector: PDA (190 nm to 400 nm), 230 nm extraction, Ram temperature: 40 ° C
Injection volume: 5 μl

  As can be seen from Table 1, in the sheet-like pressure sensitive adhesive according to the example, no bubbles were generated at any of the interface with the PEN film and the interface with the glass hard substrate. On the other hand, it was found that bubbles were generated in the sheet-like pressure-sensitive adhesive of the comparative example and it was difficult to use it as a temporary fixing material for the flexible substrate.

DESCRIPTION OF SYMBOLS 1 Base material 2 Sheet-like adhesive 3 Separator 10 Adhesive laminated body

Claims (17)

  After heating the laminated body which bonded the polyethylene naphthalate film and the sheet adhesive for 30 minutes at 180 degreeC, the sheet form which does not have a bubble substantially in the interface of the said polyethylene naphthalate film and the said sheet adhesive Adhesive.   2. A laminate comprising a glass hard substrate and the sheet-like pressure-sensitive adhesive bonded together is heated at 180 ° C. for 30 minutes, and then substantially no bubbles are present at the interface between the glass hard substrate and the sheet-like pressure-sensitive adhesive. The sheet-like pressure-sensitive adhesive described in 1.   The sheet-like pressure-sensitive adhesive according to claim 1 or 2, wherein the sheet-like pressure-sensitive adhesive after heating the sheet-like pressure-sensitive adhesive for 30 minutes at 180 ° C has a Young's modulus at 25 ° C of 0.5 MPa or more.   The sheet-like pressure-sensitive adhesive according to any one of claims 1 to 3, comprising a curable composition that is cured by heating or energy ray irradiation.   The sheet-like pressure-sensitive adhesive according to claim 4, wherein a part or all of the curing reaction of the curable composition proceeds by the first curing treatment. The curable composition contains a carbon-carbon double bond as a curable functional group,
The sheet-like pressure-sensitive adhesive according to claim 4 or 5, wherein the residual ratio of the carbon-carbon double bond after heating the sheet-like pressure-sensitive adhesive at 180 ° C for 30 minutes is 60% or less. A part of the curing reaction of the curable composition proceeds by the first curing treatment,
The sheet-like pressure-sensitive adhesive according to claim 5 or 6, wherein a curing reaction of the remainder of the curable composition proceeds by a second curing process performed after the first curing process.   The sheet-like pressure-sensitive adhesive according to claim 7, wherein the first curing treatment is heating, and the second curing treatment is energy ray irradiation.   The sheet-like pressure-sensitive adhesive according to any one of claims 6 to 8, comprising 100 ppm or more of a radical generator that generates radicals by heating or energy beam irradiation.   A pressure-sensitive adhesive laminate comprising a base material and the sheet-like pressure-sensitive adhesive according to any one of claims 1 to 9 laminated on the base material. A method for producing a flexible member using the sheet-like pressure-sensitive adhesive according to claim 1,
A laminate preparation step for preparing a laminate in which a flexible substrate is fixed on a hard substrate via the sheet-like adhesive,
The manufacturing method of the flexible member which includes the process process which processes the said flexible substrate, and produces the flexible member, and the peeling process which peels the said flexible member from the said sheet-like adhesive. The sheet-like pressure-sensitive adhesive contains a curable composition,
The manufacturing method of the flexible member of Claim 11 which performs a 1st hardening process before the said process process or during a process process, and advances the one or all hardening reaction of the said curable composition. After the laminate preparation step and before the processing step, or during the processing step, the first curing treatment is performed to advance a partial curing reaction of the curable composition,
The manufacturing method of the flexible member of Claim 12 which performs the 2nd hardening process by energy beam irradiation after the said process process and before the said peeling process, and advances the hardening reaction of the remainder of the said curable composition.   The method for producing a flexible member according to claim 11, wherein the glass transition point of the flexible substrate is 50 ° C. or higher.   The method of manufacturing a flexible member according to claim 11, wherein the flexible substrate has a thickness of 0.5 mm or less.   The method for manufacturing a flexible member according to claim 11, wherein the flexible substrate includes plastic.   The film-like display device obtained by the manufacturing method of the flexible member of Claims 11-16.

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