JP2015196783A - sheet-like composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sheet-like composition which is excellent in handleability since it is sheet-like, can be plasticized by being heated, can be cured at relatively low temperature, has small volume change at curing and enables a cured article excellent in moisture-proof property to be formed.SOLUTION: There is provided the sheet-like composition containing an epoxy resin having a weight average molecular weight of 20000 to 200000, an alicyclic epoxy compound (B) and a photo cationic polymerization initiator (C) and having a glass transition temperature of 30 to 90°C.

Description

  The present invention relates to a sheet-like composition. In detail, it is related with the sheet-like composition which can be preferably used especially as a sealing sheet of an organic EL element.

  Various resin materials are used as materials constituting members in electronic devices such as organic EL devices (organic electroluminescence devices), light emitting diode devices, displays (for example, liquid crystal display devices and touch panels), and optical members such as lenses. ing. As such a resin material, from the viewpoint of heat resistance, a cured product (resin cured product) of a heat or photocurable composition is widely used. It is preferably used as a sealing material for protecting from moisture and the like. For example, an epoxy resin, a secondary thiol, and a curing accelerator that is an imidazole compound, an amine compound, or a nitrogen-containing heterocyclic compound included in a host are used as a sealing material for an organic EL element. A one-pack type epoxy resin composition is known (see Patent Document 1).

JP 2014-1291 A

  As an epoxy resin composition disclosed in Patent Document 1, many resin materials used as a sealing material are in a liquid state in a state before curing, that is, in a state of a heat or photocurable composition. It is used. However, in consideration of handling properties and operability in the sealing operation, it is beneficial to be solid before curing.

  There are several resin materials in the market before curing that are used for sealing applications such as organic EL elements, and mainly have a sheet-like (film-like) shape. A thermosetting sealing sheet (sealing film) that can be cured by heating and then converted into a sealing material (cured product) after coating the element; has a sheet-like shape and is thermocompression-bonded to the element After being coated, there are two types: a photo-curing sealing sheet that can be semi-cured by irradiation with light and then cured by heating to be converted into a sealing material (cured product). Both thermosetting and photocurable encapsulating sheets can be handled as sheets, can be plasticized by heating, and can be cured by heating at higher temperatures or by light irradiation.

  However, among the above-described sealing sheets, the thermosetting sealing sheet has a potting reaction because the curing reaction of the sealing sheet proceeds to some extent by heating to remove the solvent during the manufacturing of the sealing sheet. Had the problem of short life. Further, in order to eliminate such a pot life problem, a method is considered in which the composition of the sealing sheet is not cured at the temperature at which the solvent is removed. Since it is necessary to increase the temperature, there arises a problem that the element deteriorates during sealing.

  On the other hand, the photo-curable sealing sheet is advantageous in that it does not have the problem of pot life in the thermosetting sealing sheet. However, since the known photo-curing type sealing sheet needs to be heated after irradiation with light at a high temperature of about 120 ° C., there is still a problem that the element deteriorates during sealing. In addition, the known photo-curing type sealing sheet has a large curing shrinkage rate, and it is a failure due to residual stress in products such as organic EL devices (specifically, the sealing sheet is peeled off due to destruction of the organic EL element or insufficient adhesion). , Warping of the device, etc.) is likely to occur.

  In addition, as described above, the photocuring type sealing sheet needs to be irradiated with light after coating the element by thermocompression bonding, so that the element is exposed to light at the time of curing, and this also deteriorates the element. There was a problem of doing.

Accordingly, the object of the present invention is a sheet-like form, which is excellent in handling properties, can be plasticized by heating, can be cured at a relatively low temperature, has a small volume change upon curing, and has excellent moisture resistance. It is providing the sheet-like composition which can form a thing.
In addition, another object of the present invention is a sheet-like shape, which is excellent in handling properties, can be plasticized by heating without being cured only by irradiation with light, and can be cured at a lower temperature. An object of the present invention is to provide a sheet-like composition that can form a cured product having a small volume change and excellent moisture resistance.

  As a result of diligent studies to solve the above problems, the present inventors include an epoxy resin having a specific weight average molecular weight, an alicyclic epoxy compound, and a photocationic polymerization initiator as essential components, and having a specific range. Since the sheet-like composition having a glass transition temperature is in a sheet form, it is excellent in handling properties, can be plasticized by heating, can be cured at a relatively low temperature, has a small volume change upon curing, and is moisture-proof. It has been found that an excellent cured product can be formed. Further, the present inventors, when the sheet-like composition further contains a curing retardant, is excellent in handling properties because it is in the form of a sheet, can be plasticized by heating without being cured only by irradiation with light, It has been found that it can be cured at a lower temperature, a volume change at the time of curing is small, and a cured product having excellent moisture resistance can be formed. The present invention has been completed based on these findings.

  That is, this invention is a sheet-like composition, Comprising: The epoxy resin (A) whose weight average molecular weight is 20000-200000, an alicyclic epoxy compound (B), and a photocationic polymerization initiator (C). And a glass transition temperature of 30 to 90 ° C. is provided.

  Furthermore, the said sheet | seat whose content of an alicyclic epoxy compound (B) is 5 to 40 weight% with respect to the total amount (100 weight%) of an epoxy resin (A) and an alicyclic epoxy compound (B). A composition is provided.

  Furthermore, the said sheet-like composition containing a hardening retarder (D) is provided.

  Furthermore, the sheet-like composition is provided in which the alicyclic epoxy compound (B) is 3,4,3 ′, 4′-diepoxybicyclohexyl.

  Furthermore, the said sheet-like composition which is a sealing sheet for electronic devices is provided.

Since the sheet-like composition of the present invention has the above-described configuration, it is in a sheet form and has excellent handling properties, can be plasticized by heating, can be cured at a relatively low temperature, and has a small volume change upon curing, A cured product having excellent moisture resistance can be formed. Therefore, especially the sheet-like composition of this invention can be preferably used as a sealing sheet (sealing sheet for organic EL elements) for sealing an organic EL element. When the sheet-like composition of the present invention is used as a sealing sheet for an organic EL device, the sheet-like composition enables a sealing work with a roll-to-roll to improve workability. Therefore, the organic EL element can be easily coated by thermocompression bonding, and thereafter cured at a relatively low temperature, so that the organic EL element is hardly deteriorated. For this reason, when the sheet-shaped composition of this invention is used, the productivity and quality of an organic EL device improve remarkably.
In particular, when the sheet-like composition of the present invention contains a curing retarder (D) described later, in addition to the above-mentioned merit, it can be plasticized by heating without being cured only by irradiation with light. Moreover, the effect that it can harden | cure at lower temperature (for example, 100 degrees C or less) is also acquired. For this reason, the organic EL element can be sealed by a process in which the element is not exposed to light during curing. In this case, the quality of the organic EL device is further improved.

It is an example of the scanning electron microscope image of electroconductive fiber covering particle | grains. It is the schematic (sectional drawing) which shows an example of the method of sealing an organic EL element using the sheet-like composition of this invention. It is the schematic (sectional drawing) which shows another example of the method of sealing an organic EL element using the sheet-like composition of this invention. It is the schematic (sectional drawing) which shows an example of the method of sealing an organic EL element using the laminated body which has a sheet-like composition of this invention.

<Sheet composition>
The sheet-like composition of the present invention is a sheet-like composition having a weight average molecular weight of 20,000 to 200,000 (referred to simply as “epoxy resin (A)” or “component (A)”) An alicyclic epoxy compound (B) (sometimes referred to as “component (B)”), a photocationic polymerization initiator (C) (sometimes referred to as “component (C)”), Is a sheet-like composition having a glass transition temperature of 30 to 90 ° C. Since the sheet-like composition of the present invention contains the component (A) and the component (B) having cationic curability as essential components, it is a curable sheet that can be converted into a cured product by curing. The “sheet” in the sheet-like composition of the present invention includes the concept of both a sheet and a film.

  The sheet-like composition of this invention should just contain an epoxy resin (A), an alicyclic epoxy compound (B), and a photocationic polymerization initiator (C) as an essential component, for example, further epoxy It may be one containing a polymer of a cationic curable compound such as resin (A) or alicyclic epoxy compound (B) (so-called partial polymer).

[Epoxy resin (A)]
The epoxy resin (A) in the sheet-like composition of the present invention is an epoxy resin having a weight average molecular weight of 20,000 to 200,000 (a compound having one or more epoxy groups in the molecule). The sheet-like composition of the present invention can exhibit excellent handling properties as a sheet by including the epoxy resin (A). In addition, the compound which has an epoxy group (alicyclic epoxy group) comprised by two adjacent carbon atoms and oxygen atoms which comprise an alicyclic ring is excluded from an epoxy resin (A).

  The epoxy resin (A) is not particularly limited as long as it is a compound having a weight average molecular weight in the range of 20,000 to 200,000 and having one or more (preferably two or more) epoxy groups in the molecule. Bisphenol type epoxy resin such as A type epoxy resin, bisphenol F type epoxy resin, bisphenol E type epoxy resin, bisphenol S type epoxy resin, bisphenol Z type epoxy resin, bisphenol P type epoxy resin, bisphenol M type epoxy resin; Novolak type epoxy resins such as epoxy resins and cresol novolac epoxy resins; biphenyl type epoxy resins; xylylene type epoxy resins, biphenyl aralkyl type epoxy resins (for example, biphenyl dimethylene type epoxy resins, etc.) Arylalkylene type epoxy resins such as naphthalene type epoxy resins; anthracene type epoxy resins; dicyclopentadiene type epoxy resins; norbornene type epoxy resins; adamantane type epoxy resins; fluorene type epoxy resins; bisphenol A type phenoxy resins, bisphenol F type phenoxy Resin, bisphenol S type phenoxy resin, bisphenol M type phenoxy resin, bisphenol P type phenoxy resin, bisphenol Z type phenoxy resin, phenoxy resin having two or more bisphenol skeletons (for example, bisphenol A type epoxy resin and bisphenol F type epoxy resin) Bisphenol type phenoxy resin, novolac type phenoxy resin, naphthalene type phenoxy resin, biphenyl type phenoxy resin, etc. Phenoxy resin (phenoxy type epoxy resin) such as resin; Hydrogenated epoxy resin of the above epoxy resin such as hydrogenated bisphenol A type epoxy resin, hydrogenated bisphenol F type epoxy resin, hydrogenated naphthalene type epoxy resin, etc .: Examples thereof include polymers.

  Although the weight average molecular weight of an epoxy resin (A) should just be 20000-200000 and it does not specifically limit, 30000-150,000 are preferable, More preferably, it is 40000-80000. By setting the weight average molecular weight of the epoxy resin (A) to 20000 or more, the handleability as a sheet is improved, for example, the tack of the sheet-like composition is reduced. On the other hand, by setting the weight average molecular weight of the epoxy resin (A) to 200,000 or less, it is easy to prepare a coating liquid for forming a sheet-like composition, and the viscosity does not become too high. Productivity is improved. In addition, the said weight average molecular weight is a weight average molecular weight of standard polystyrene conversion measured by gel permeation chromatography.

  In the sheet-like composition of the present invention, the epoxy resin (A) can be used alone or in combination of two or more. Moreover, an epoxy resin (A) can also be manufactured by a well-known thru | or usual method, and a commercial item can also be obtained.

  Although content (blending amount) of the epoxy resin (A) in the sheet-like composition of the present invention is not particularly limited, it is preferably 50 to 95% by weight, more preferably based on the sheet-like composition (100% by weight). Is 60 to 92% by weight, more preferably 65 to 90% by weight. By setting the content of the epoxy resin (A) to 50% by weight or more, the handleability as a sheet tends to be further improved, for example, the tack of the sheet-like composition is further reduced. On the other hand, since the amount of the alicyclic epoxy compound (B) can be relatively increased by setting the content of the epoxy resin (A) to 95% by weight or less, it can be cured at a lower temperature. The volume change at the time of curing tends to be smaller.

[Alicyclic epoxy compound (B)]
The alicyclic epoxy compound (B) in the sheet-like composition of the present invention is a compound having at least an alicyclic (aliphatic ring) structure and an epoxy group (oxiranyl group) in the molecule. It is a compound having an epoxy group (alicyclic epoxy group) composed of two adjacent carbon atoms and oxygen atoms. By including the alicyclic epoxy compound (B), the sheet-like composition of the present invention can be cured at a relatively low temperature, and the volume change upon curing is small.

As the alicyclic epoxy group possessed by the alicyclic epoxy compound (B), in particular, from the viewpoint of curability and curing shrinkage, a cyclohexene oxide group (consisting of two adjacent carbon atoms and oxygen atoms constituting the cyclohexane ring) Epoxy group). That is, the alicyclic epoxy compound (B) is preferably a compound having a cyclohexene oxide group (more preferably a compound having two or more cyclohexene oxide groups in the molecule), and particularly preferably represented by the following formula (a). It is a compound.

In the above formula (a), R ^{1 to} R ¹⁸ may be the same or different and each may have a hydrogen atom, a halogen atom, an oxygen atom, a hydrocarbon group that may contain a halogen atom, or a substituent. An alkoxy group is shown.

Examples of the halogen atom as R ¹ to R ^18, for example, a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.

Examples of the hydrocarbon group as R ^{1 to} R ¹⁸ include an aliphatic hydrocarbon group, an alicyclic hydrocarbon group, an aromatic hydrocarbon group, and a group in which two or more of these are bonded.

Examples of the aliphatic hydrocarbon group include C _1-20 alkyl groups such as a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a hexyl group, an octyl group, an isooctyl group, a decyl group, and a dodecyl group (preferably Is a C _1-10 alkyl group, particularly preferably a C _1-4 alkyl group); vinyl group, allyl group, methallyl group, 1-propenyl group, isopropenyl group, 1-butenyl group, 2-butenyl group, 3-butenyl group group, 1-pentenyl group, 2-pentenyl group, 3-pentenyl group, 4-pentenyl group, 5-hexenyl C _2-20 alkenyl groups such as groups (preferably C _2-10 alkenyl group, particularly preferably a C _{2- 4} alkenyl group); C _2-20 alkynyl group (preferably C _2-10 alkynyl group, particularly preferably C _2-4 alkynyl group) such as ethynyl group and propynyl group.

Examples of the alicyclic hydrocarbon group include C _3-12 cycloalkyl groups such as cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group, and cyclododecyl group; C _3-12 cycloalkenyl groups such as cyclohexenyl group. A C _4-15 bridged cyclic hydrocarbon group such as a bicycloheptanyl group and a bicycloheptenyl group;

As said aromatic hydrocarbon group, _C6-14 aryl groups (preferably _C6-10 aryl group), such as a phenyl group and a naphthyl group, etc. are mentioned, for example.

Examples of the group in which two or more groups selected from the above aliphatic hydrocarbon group, alicyclic hydrocarbon group, and aromatic hydrocarbon group are bonded include, for example, C _3-12 cyclohexane such as cyclohexylmethyl group. Alkyl-C _1-20 alkyl group; C _1-20 alkyl-substituted C _3-12 cycloalkyl group such as methylcyclohexyl group and dimethylcyclohexyl group; C _7-18 aralkyl group such as benzyl group and phenethyl group (particularly C _{7 -10} aralkyl group); C _6-14 aryl-C _2-20 alkenyl group such as cinnamyl group; C _1-20 alkyl substituted C _6-14 aryl group such as tolyl group; C _2-20 alkenyl substituted such as styryl group And C _6-14 aryl group.

Examples of the hydrocarbon group containing an oxygen atom or a halogen atom as R ^{1 to} R ¹⁸ include a group in which at least one hydrogen atom in the above-described hydrocarbon group is substituted with a group having an oxygen atom or a halogen atom. . Examples of the group having an oxygen atom include hydroxyl group; hydroperoxy group; C _1-10 alkoxy group such as methoxy group, ethoxy group, propoxy group, isopropyloxy group, butoxy group, and isobutyloxy group; C _2-10 alkenyloxy group; C _1-10 alkyl group, C _2-10 alkenyl group, a halogen atom, and C _1-10 optionally C _6-14 optionally having a substituent selected from alkoxy groups Aryloxy groups (for example, tolyloxy group, naphthyloxy group, etc.); C _7-18 aralkyloxy groups such as benzyloxy group, phenethyloxy group; acetyloxy group, propionyloxy group, (meth) acryloyloxy group, benzoyloxy group C _1-10 acyloxy group such as methoxycarbonyl group, ethoxycarbonyl group, propoxycarbonyl group, butoxy C _1-10 alkoxycarbonyl group such as carbonyl group; C _1-10 alkyl group, C _2-10 alkenyl group, halogen atom, and optionally substituted substituent selected from C _1-10 alkoxy group _6-14 aryloxycarbonyl group (for example, phenoxycarbonyl group, tolyloxycarbonyl group, naphthyloxycarbonyl group, etc.); C _7-18 aralkyloxycarbonyl group such as benzyloxycarbonyl group; epoxy group-containing group such as glycidyloxy group ; ethyloxetanyl oxetanyl group-containing group such as aryloxy group; isocyanate group; a sulfo group; a carbamoyl group; oxo group; an acetyl group, a propionyl group, C _1-10 acyl group such as benzoyl group 2 or more of these C _{1- And} a group bonded through or without an alkylene group.

Examples of the alkoxy group as R ^{1 to} R ¹⁸ include C _1-10 alkoxy groups such as a methoxy group, an ethoxy group, a propoxy group, an isopropyloxy group, a butoxy group, and an isobutyloxy group.

Examples of the substituent that the alkoxy group may have include, for example, a halogen atom, a hydroxyl group, a C _1-10 alkoxy group, a C _2-10 alkenyloxy group, a C _6-14 aryloxy group, and a C _1-10. Acyloxy group, mercapto group, C _1-10 alkylthio group, C _2-10 alkenylthio group, C _6-14 arylthio group, C _7-18 aralkylthio group, carboxyl group, C _1-10 alkoxycarbonyl group, C _{6- 14} aryloxycarbonyl group, C _7-18 aralkyloxycarbonyl group, amino group, mono or di C _1-10 alkylamino group, C _1-10 acylamino group, epoxy group-containing group, oxetanyl group-containing group, C _1-10 Examples include an acyl group, an oxo group, and a group in which two or more of these are bonded via a C _1-10 alkylene group or the like.

  In the above formula (a), X represents a single bond or a linking group (a divalent group having one or more atoms). Examples of the linking group include divalent hydrocarbon groups, alkenylene groups in which part or all of carbon-carbon double bonds are epoxidized, carbonyl groups, ether bonds, ester bonds, carbonate groups, amide groups, and the like. And a group in which a plurality of are connected.

  As said bivalent hydrocarbon group, a C1-C18 linear or branched alkylene group, a bivalent alicyclic hydrocarbon group, etc. are mentioned, for example. Examples of the linear or branched alkylene group having 1 to 18 carbon atoms include a methylene group, a methylmethylene group, a dimethylmethylene group, an ethylene group, a propylene group, and a trimethylene group. Examples of the divalent alicyclic hydrocarbon group include 1,2-cyclopentylene group, 1,3-cyclopentylene group, cyclopentylidene group, 1,2-cyclohexylene group, 1,3-cyclopentylene group, And divalent cycloalkylene groups (including cycloalkylidene groups) such as cyclohexylene group, 1,4-cyclohexylene group, and cyclohexylidene group.

  Examples of the alkenylene group in the alkenylene group in which part or all of the carbon-carbon double bond is epoxidized (sometimes referred to as “epoxidized alkenylene group”) include, for example, a vinylene group, a propenylene group, and a 1-butenylene group. , A 2-butenylene group, a butadienylene group, a pentenylene group, a hexenylene group, a heptenylene group, an octenylene group, etc., and a linear or branched alkenylene group having 2 to 8 carbon atoms. In particular, the epoxidized alkenylene group is preferably an alkenylene group in which all of the carbon-carbon double bonds are epoxidized, more preferably 2 to 4 carbon atoms in which all of the carbon-carbon double bonds are epoxidized. Alkenylene group.

  The linking group X is particularly preferably a linking group containing an oxygen atom, specifically, —CO—, —O—CO—O—, —COO—, —O—, —CONH—; An alkenylene group; a group in which a plurality of these groups are linked; a group in which one or more of these groups are linked to one or more of divalent hydrocarbon groups, and the like.

  Examples of the compound in which X in the above formula (a) is a single bond include 3,4,3 ', 4'-diepoxybicyclohexyl.

Representative examples of the compound represented by the above formula (a) include compounds represented by the following formulas (1) to (10). In the following formulas (5) and (7), n ¹ and n ² each represent an integer of 1 to 30. L in the following formula (5) is an alkylene group having 1 to 8 carbon atoms, methylene group, ethylene group, propylene group, isopropylene group, butylene group, isobutylene group, s-butylene group, pentylene group, hexylene group, Examples thereof include linear or branched alkylene groups such as a heptylene group and an octylene group. Among these, C1-C3 linear or branched alkylene groups, such as a methylene group, ethylene group, a propylene group, an isopropylene group, are preferable. N < ³ > -n < ⁸ > in following formula (9), (10) is the same or different, and shows the integer of 1-30.

  Among these, as the alicyclic epoxy compound (B), particularly from the viewpoints of curability of the sheet-like composition, low curing shrinkage, heat resistance of the cured product (for example, glass transition temperature, etc.), low linear expansion coefficient, and moisture resistance. A compound represented by formula (a), wherein X is a single bond; a linear or branched alkylene group having 1 to 6 carbon atoms; a linear or branched alkylene group having 1 to 4 carbon atoms; A divalent group having 2 to 10 carbon atoms formed by linking one or more of the above and one or more ester bonds (—COO—); an epoxidized alkenylene group having 2 to 4 carbon atoms; or 1 carbon atom A compound which is a divalent group having 2 to 10 carbon atoms formed by linking one or more of -4 linear or branched alkylene groups and one or more of ether bonds (-O-), A compound represented by the formula (10) is preferable, and more preferably 3,4,3 ′, 4 ′. Diepoxybicyclohexyl, 2,2-bis (3,4-epoxycyclohexyl) propane, 1,2-bis (3,4-epoxycyclohexyl) ethane, 2,3-bis (3,4-epoxycyclohexyl) oxirane, Bis (3,4-epoxycyclohexylmethyl) ether, compound represented by formula (1), compound represented by formula (10), more preferably 3,4,3 ′, 4′-diepoxybicyclohexyl is there.

  In the sheet-like composition of the present invention, the alicyclic epoxy compound (B) can be used alone or in combination of two or more. In addition, an alicyclic epoxy compound (B) can also be manufactured by a well-known thru | or usual method, for example, can be manufactured by epoxidizing the double bond part of a corresponding olefin compound. Moreover, an alicyclic epoxy compound (B) can also be obtained as a commercial item.

  Although content (blending amount) of the alicyclic epoxy compound (B) in the sheet-like composition of the present invention is not particularly limited, it is 3 to 40% by weight with respect to the total amount (100% by weight) of the sheet-like composition. Is more preferable, more preferably 5 to 35% by weight, still more preferably 8 to 30% by weight. By setting the content of the alicyclic epoxy compound (B) to 3% by weight or more, the curability of the sheet-like composition is improved, and there is a tendency that it can be cured by lower temperature heating. If it can be cured at a lower temperature, the curing reaction is likely to proceed sufficiently, so that the moisture resistance of the cured product tends to be improved. Moreover, the volume change at the time of hardening tends to be small. On the other hand, by setting the content of the alicyclic epoxy compound (B) to 40% by weight or less, there is a tendency that a sheet-like composition having low tack or tack and having excellent handling properties can be efficiently produced.

  Although content (blending amount) of the alicyclic epoxy compound (B) in the sheet-like composition of the present invention is not particularly limited, the total amount (100 wt.%) Of the epoxy resin (A) and the alicyclic epoxy compound (B). %) To 5 to 40% by weight, more preferably 8 to 35% by weight, still more preferably 10 to 30% by weight. By setting the content of the alicyclic epoxy compound (B) to 5% by weight or more, the curability of the sheet-like composition is improved, and there is a tendency that it can be cured by heating at a lower temperature. Moreover, the volume change at the time of hardening tends to be small. On the other hand, by setting the content of the alicyclic epoxy compound (B) to 40% by weight or less, there is a tendency that a sheet-like composition having low tack or tack and having excellent handling properties can be efficiently produced.

  Although the total amount of the epoxy resin (A) and the alicyclic epoxy compound (B) with respect to the sheet-like composition (100% by weight) of the present invention is not particularly limited, the handling property, curability, and the viewpoint of volume change upon curing Is preferably 80% by weight or more (for example, 80% by weight or more and less than 100% by weight), more preferably 90% by weight or more (for example, 90 to 99% by weight). Further, the total amount of the epoxy resin (A) and the alicyclic epoxy compound (B) with respect to the total amount (100% by weight) of the cationic curable compound contained in the sheet-like composition of the present invention is not particularly limited, but handling properties are not limited. From the viewpoints of curability and volume change during curing, 90% by weight or more (for example, 90 to 100% by weight) is preferable, and more preferably 95% by weight or more.

[Photocationic polymerization initiator (C)]
The photocationic polymerization initiator (C) in the sheet-like composition of the present invention initiates a polymerization reaction of a cationic curable compound such as component (A) or component (B) by light irradiation, and cures the sheet-like composition. For the compound. The cationic photopolymerization initiator (C) usually comprises a cation moiety that absorbs light and an anion moiety that serves as a source of acid generation. In the sheet-like composition of the present invention, since the photocationic polymerization initiator (C) is used as the polymerization initiator, there is a problem in the conventional thermosetting sealing sheet using the thermal polymerization initiator (the sealing sheet The problem that the curing reaction proceeds to some extent by heating to remove the solvent during production does not occur. The sheet-like composition of the present invention has no pot life or has a very long pot life.

  As the cationic photopolymerization initiator (C), known or conventional photopolymerization initiators can be used, and are not particularly limited. Examples thereof include diazonium salt compounds, iodonium salt compounds, sulfonium salt compounds, and phosphonium salts. Compound, selenium salt compound, oxonium salt compound, ammonium salt compound, bromine salt compound and the like.

  Among these, as the cationic photopolymerization initiator (C), a sulfonium salt compound is preferable from the viewpoint of curability of the sheet-like composition. Examples of the cation moiety of the sulfonium salt compound include arylsulfonium ions (particularly, triarylsulfonium ions) such as triphenylsulfonium ion, diphenyl [4- (phenylthio) phenyl] sulfonium ion, and tri-p-tolylsulfonium ion. Is mentioned.

Examples of the anion moiety of the photocationic polymerization initiator (C) include BF ₄ ⁻ , B (C ₆ F ₅ ) ₄ ⁻ , PF ₆ ⁻ , [(Rf) _n PF _6−n ] ⁻ (Rf: hydrogen atom An alkyl group in which 80% or more of them are substituted with a fluorine atom, n is an integer of 1 to 5), AsF ₆ ⁻ , SbF ₆ ⁻ , pentafluorohydroxyantimonate, and the like.

  Specific examples of the cationic photopolymerization initiator (C) include 4- (4-biphenylthio) phenyl-4-biphenylphenylsulfonium tetrakis (pentafluorophenyl) borate and diphenyl [4- (phenylthio) phenyl]. Sulfonium tetrakis (pentafluorophenyl) borate, diphenyl [4- (phenylthio) phenyl] sulfonium hexafluorophosphate, 4- (4-biphenylthio) phenyl-4-biphenylphenylsulfonium tris (pentafluoroethyl) trifluorophosphate, commodity Names "Syracure UVI-6970", "Syracure UVI-6974", "Syracure UVI-6990", "Syracure UVI-950" (manufactured by Union Carbide, USA), products "Irgacure 250", "Irgacure 261", "Irgacure 264" (above, manufactured by BASF), trade names "SP-150", "SP-151", "SP-170", "Optomer SP-171" (above , Manufactured by ADEKA Corporation), trade name “CG-24-61” (manufactured by BASF), trade name “DAICAT II” (manufactured by Daicel Corporation), trade names “UVAC1590”, “UVAC1591” (above, Daicel)・ Cytech Co., Ltd.), trade names “CI-2064”, “CI-2639”, “CI-2624”, “CI-2481”, “CI-2734”, “CI-2855”, “CI-2823” ”,“ CI-2758 ”,“ CIT-1682 ”(manufactured by Nippon Soda Co., Ltd.), trade name“ PI-2074 ”(manufactured by Rhodia, pentafluoropheny) Borate tolylcumyl iodonium salt), trade name “FFC509” (manufactured by 3M), trade names “BBI-102”, “BBI-101”, “BBI-103”, “MPI-103”, “TPS-103” , "MDS-103", "DTS-103", "NAT-103", "NDS-103" (manufactured by Midori Chemical Co., Ltd.), trade names "CD-1010", "CD-1011", " CD-1012 "(manufactured by Sartomer, USA), trade names" CPI-100P "," CPI-101A "," CPI-210S "(manufactured by San Apro Co., Ltd.) and the like.

  In the sheet-like composition of the present invention, the photocationic polymerization initiator (C) can be used alone or in combination of two or more.

  The content (blending amount) of the photocationic polymerization initiator (C) in the sheet-like composition of the present invention is not particularly limited, but the total amount (total amount) of the cationic curable compound contained in the sheet-like composition is 100 parts by weight. On the other hand, 0.5-4 weight part is preferable, More preferably, it is 0.2-2 weight part. By controlling the content of the cationic photopolymerization initiator (C) in the above range, the sheet-like composition can be cured more efficiently, and the degree of curing of the resulting cured product can be further increased. There exists a tendency which the moisture-proof property of hardened | cured material improves more.

[Curing retarder (D)]
The sheet-like composition of the present invention may further contain a curing retarder (D) (sometimes referred to as “component (D)”). When the sheet-like composition of the present invention contains a curing retarder (D), cations generated from the photocationic polymerization initiator (C) by light irradiation are trapped by the curing retarder (D). Without being cured, it can be plasticized by heating. Thereafter, the cations trapped by the curing retarder (D) can be released by heating, and the curing reaction of the sheet-like composition proceeds. However, the heating at this time is relatively low (for example, 100 ° C. or less). Even so, the curing reaction can sufficiently proceed. For this reason, when a curing retarder (D) is included, as a sealing operation for an organic EL element or the like, first, the sheet-like composition is irradiated with light (the curing reaction does not proceed at this point), and then thermocompression bonding is performed. The element can be coated by the above method, and then heated and cured at a low temperature. In this process, the device is not exposed to light during curing, and high-temperature heat is not applied to the device, so that deterioration of the device in the sealing operation is remarkably suppressed.

  As the curing retarder (D), known or conventional compounds that can retard curing by cationic polymerization can be used, and are not particularly limited, but polyethylene glycol, polypropylene glycol, polytetramethylene glycol, and crown ether compounds. Polyether compounds such as 12-crown-4, 15-crown-5, 18-crown-6, 24-crown-8, etc .; pyrrole compounds, pyrazole compounds, 3,5-dimethylpyrazole compounds, imidazoles Examples thereof include azole compounds such as compounds, 1,2,3-triazole compounds, and 1,2,4-triazole compounds.

  Among these, as the curing retarder (D), an azole compound is preferable in that it does not generate outgas and does not deteriorate the device. In particular, 3,5-dimethylpyrazole is preferable in that it exhibits cure retardance at room temperature and can be rapidly cured by heating at a temperature of 100 ° C. or lower.

  In addition, in the sheet-like composition of this invention, a hardening retarder (D) can also be used individually by 1 type, and can also be used in combination of 2 or more type. Moreover, a hardening retarder (D) can also be manufactured by a well-known thru | or usual method, and a commercial item can also be obtained.

  The content (blending amount) of the curing retarder (D) in the sheet-like composition of the present invention is not particularly limited, but is 100 parts by weight based on the total amount of the photocationic polymerization initiator (C) contained in the sheet-like composition. The amount is preferably 50 to 400 parts by weight, more preferably 50 to 300 parts by weight, and still more preferably 100 to 250 parts by weight. Controlling the content of the curing retarder (D) within the above range is particularly preferable from the viewpoint of obtaining a satisfactory curing retarding effect. Specifically, by setting the content of the curing retarder (D) to 50 parts by weight or more, there is a tendency that a more sufficient curing retardation effect can be obtained. On the other hand, by setting the content of the curing retarder (D) to 400 parts by weight or less, it can be cured at a sufficient rate by heating after light irradiation, and there is a tendency that poor curing is less likely to occur.

[Cure retarding stabilizer (E)]
The sheet-like composition of the present invention may further contain a curing retardation stabilizer (E) (sometimes referred to as “component (E)”) (particularly when the curing retardation agent (D) is included). . As the curing delay stabilizer (E), a known or conventional compound having a curing delay stabilization effect can be used, and is not particularly limited, but is a compound having at least one allyl ether group in the molecule (“allyl ether”). Are sometimes referred to as “compounds”).

  Examples of the allyl ether compound include 2,2-bis (4-allyloxyphenyl) propane, 2,2'-bis (allyloxy) -1,1'-biphenyl, and the like. For example, commercially available products such as trade name “BPA-AE” (manufactured by Konishi Chemical Industry Co., Ltd.) can be used.

  Among them, as the allyl ether compound, it is possible to give the effect of stabilizing the curing retardation while suppressing the generation of outgas, and a cured product having excellent moisture resistance (low moisture permeability) can be formed. A compound having at least one allyl ether group in the molecule and having no ester bond or polyether structure is preferred.

  The content (blending amount) of the curing delay stabilizer (E) in the sheet-like composition of the present invention is not particularly limited, but is 10 with respect to 100 parts by weight of the total amount of the cationic curable compound contained in the sheet-like composition. -70 weight part is preferable, More preferably, it is 20-50 weight part. It is preferable that the component (E) is contained in the above range in terms of stabilizing the curing retardation.

  Further, the total content (total content) of the component (D) and the component (E) with respect to 100 parts by weight of the total amount of the cationic curable compound contained in the sheet-shaped composition of the present invention is not particularly limited. -70 weight part is preferable, More preferably, it is 20-50 weight part. Controlling the total content within the above range is preferable in that the retardation of curing can be further stabilized.

  Further, the sheet-like composition of the present invention may contain a cationic curable compound other than the component (A) and the component (B) (sometimes referred to as “other cationic curable compounds”). Examples of other cationic curable compounds include compounds having two or more oxetane ring-containing groups in the molecule (oxetane compounds), compounds having two or more episulfide groups in the molecule (episulfide compounds), Compound having two or more vinyl ether groups (vinyl ether compound), epoxy compound other than component (A) and component (B) (sometimes referred to as “other epoxy compounds”), compound having vinyl group (vinyl compound) And compounds having an allyl group (allyl compounds).

  Examples of the oxetane compound include 1,4-bis [(3-ethyl-3-oxetanylmethoxy) methyl] benzene, bis {[1-ethyl (3-oxetanyl)] methyl} ether, 4,4′-bis. [(3-Ethyl-3-oxetanyl) methoxymethyl] bicyclohexyl, 1,4-bis [(3-ethyl-3-oxetanyl) methoxymethyl] cyclohexane, 3-ethyl-3 {[(3-ethyloxetane-3 -Yl) methoxy] methyl} oxetane, phenol novolac oxetane and the like. For example, a commercial product such as a trade name “ETERARNACOLL OXBP” (manufactured by Ube Industries, Ltd.) can be used.

  Examples of the episulfide compound include 1,3-bis (β-epithiopropylthio) cyclohexane, 1,3-bis (β-epithiopropylthiomethyl) cyclohexane, bis [4- (β-epithiopropylthio). ) Cyclohexyl] methane, 2,2-bis [4- (β-epithiopropylthio) cyclohexyl] propane, bis [4- (β-epithiopropylthio) cyclohexyl] sulfide, 2,5-bis (β-epi Episulfide compounds having an alicyclic ring such as thiopropylthio) -1,4-dithiane, 2,5-bis (β-epithiopropylthioethylthiomethyl) -1,4-dithiane; 1,3-bis (β- Epithiopropylthio) benzene, 1,3-bis (β-epithiopropylthiomethyl), benzenebis [4- (β-epithiopropylthio) ) Phenyl] methane, 2,2-bis [4- (β-epithiopropylthio) phenyl] propane, bis [4- (β-epithiopropylthio) phenyl] sulfide, bis [4- (β-epithio) An episulfide compound having an aromatic ring such as propylthio) phenyl] sulfine and 4,4-bis (β-epithiopropylthio) biphenyl; 2- (2-β-epithiopropylthioethylthio) -1,3-bis (Β-epithiopropylthio) propane, 1,2-bis [(2-β-epithiopropylthioethyl) thio] -3- (β-epithiopropylthio) propane, tetrakis (β-epithiopropylthio) Alkyl) sulfide type episulfide compounds such as methyl) methane, 1,1,1-tris (β-epithiopropylthiomethyl) propane; 9,9-bis {4- 2- (2,3-epithiopropoxy) ethoxy] phenyl} fluorene, 9,9-bis {4- [2- (2,3-epithiopropoxy) ethoxy] -3-methylphenyl} fluorene, 9,9 -Bis {4- [2- (2,3-epithiopropoxy) ethoxy] -3,5-dimethylphenyl} fluorene, 9,9-bis {4- [2- (2,3-epithiopropoxy) ethoxy ] -3-phenylphenyl} fluorene, 9,9-bis {6- [2- (2,3-epithiopropoxy) ethoxy] -2-naphthyl} fluorene, 9,9-bis {5- [2- ( And episulfide compounds having a fluorene skeleton such as 2,3-epithiopropoxy) ethoxy] -1-naphthyl} fluorene.

  Examples of the vinyl ether compound include cyclic ether type vinyl ethers such as isosorbide divinyl ether and oxynorbornene divinyl ether (vinyl ethers having a cyclic ether group such as oxirane ring, oxetane ring and oxolane ring); aryl diesters such as hydroquinone divinyl ether Vinyl ether; Vinyl ether having a chain hydrocarbon group such as 1,4-butanediol divinyl ether; Chain ether type vinyl ether such as triethylene glycol divinyl ether; Cyclic hydrocarbon group such as cyclohexane divinyl ether and cyclohexane dimethanol divinyl ether The vinyl ether which has is mentioned.

  Examples of the other epoxy compound include an epoxy compound having a weight average molecular weight of less than 20,000, an epoxy compound having a weight average molecular weight of more than 200,000, and the like. And the like, glycidyl ether epoxy compounds, glycidyl ester epoxy compounds, glycidyl amine epoxy compounds, and the like.

  Examples of the compound in which an epoxy group is directly bonded to the alicyclic ring by a single bond include 1,2-epoxy-4- (2-oxiranyl) cyclohexane adduct of 2,2-bis (hydroxymethyl) -1-butanol ( Trade name “EHPE3150”, manufactured by Daicel Corporation), and the like.

  Examples of the glycidyl ether type epoxy compound include bisphenol A type epoxy compounds, bisphenol F type epoxy compounds, bisphenol E type epoxy compounds, o-phenylphenol glycidyl ether, biphenol type epoxy compounds, phenol novolac type epoxy compounds, and cresol novolac type. Epoxy compounds, cresol novolac epoxy compounds of bisphenol A, naphthalene epoxy compounds, aromatic glycidyl ether epoxy compounds such as epoxy compounds obtained from trisphenol methane; aliphatic glycidyl ether epoxy compounds such as aliphatic polyglycidyl ether; Hydrogenated bisphenol A epoxy compound (2,2-bis [4- (2,3-epoxypropoxy) cyclohexyl] pro 2,2-bis [3,5-dimethyl-4- (2,3-epoxypropoxy) cyclohexyl] propane, a compound obtained by hydrogenating a bisphenol A type epoxy compound such as a multimer thereof), hydrogenation Bisphenol F type epoxy compounds (bis [o, o- (2,3-epoxypropoxy) cyclohexyl] methane, bis [o, p- (2,3-epoxypropoxy) cyclohexyl] methane, bis [p, p- (2,3-epoxypropoxy) cyclohexyl] methane, bis [3,5-dimethyl-4- (2,3-epoxypropoxy) cyclohexyl] methane, multimers thereof, etc.), hydrogenated biphenol Type epoxy compound, hydrogenated phenol novolac type epoxy compound, hydrogenated cresol novolac type epoxy compound, hydrogenated cresol of bisphenol A Glycidyl ethers having a weight average molecular weight of less than 20,000 or more than 200,000, such as hydrogenated glycidyl ether type epoxy compounds such as a hydrogenated epoxy compound of a epoxy compound obtained from a borac type epoxy compound, a hydrogenated naphthalene type epoxy compound or trisphenolmethane An epoxy compound is mentioned.

  Examples of the vinyl compound include styrene compounds such as styrene, p-methylstyrene, ethyl styrene, propyl styrene, isopropyl styrene, and p-tert-butyl styrene; nitrogen vinyl compounds such as N-vinyl carbazole and N-vinyl pyrrolidone. Etc.

  Examples of the allyl compound include allyl (meth) acrylate, diallyl maleate, triallyl cyanurate, diallyl phthalate, and the like.

  In addition, another cationic curable compound can also be used individually by 1 type, and can be used in combination of 2 or more type. Other cationic curable compounds include, among others, other epoxy compounds (particularly preferably a compound having one or more glycidyl ether groups in one molecule, most preferably a glycidyl ether group in view of a slow curing rate at room temperature. The use of a compound having at least one in one molecule and having no ester bond or polyether structure can give the effect of stabilizing the curing delay while suppressing the outgassing. Is preferable.

  The content of the other cationic curable compound with respect to the total amount (100% by weight) of the cation curable compound contained in the sheet-like composition of the present invention is not particularly limited, but is preferably 0 to 10% by weight, more preferably. 1 to 8% by weight.

[Other ingredients]
The sheet-like composition of the present invention may further contain components other than the above-described components (sometimes referred to as “other components”) as long as the effects of the present invention are not adversely affected. Examples of other components include conductive materials, fillers (organic fillers and inorganic fillers), polymerization inhibitors, silane coupling agents, antioxidants, light stabilizers, plasticizers, leveling agents, antifoaming agents, and pigments. And known or commonly used additives such as an organic solvent, an ultraviolet absorber, an ion adsorbent, a pigment, a phosphor, and a release agent. The content of the additive with respect to the total amount (100% by weight) of the sheet-like composition of the present invention is not particularly limited, but is preferably 30% by weight or less, more preferably 20% by weight or less, and still more preferably 10% by weight or less. It is.

  Examples of the silane coupling agent include 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, and 2- (3,4-epoxycyclohexyl). Ethyltrimethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane, N- (2-aminoethyl) 3-aminopropylmethyldimethoxysilane, N- (2-aminoethyl) 3-aminopropylmethyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-mercaptopropyltrimethoxysilane, vinyltrimethoxysilane, N- (2- (vinylbenzylamino) ethyl) 3-aminopropyltrimethoxysilane hydrochloride, 3-methacryloyloxypropyltrimethoxy Silane and the like. Among them, 3-glycidoxypropyltrimethoxysilane (for example, trade name “KBM-403” (manufactured by Shin-Etsu Chemical Co., Ltd.), etc.) is preferable in terms of good compatibility with other components and excellent stability. . In addition, a silane coupling agent can also be used individually by 1 type, and can be used in combination of 2 or more type. When the curable resin composition of this invention contains a silane coupling agent, the adhesiveness of the hardened | cured material with respect to adherends, such as glass, can be improved more.

  Although the content (blending amount) of the silane coupling agent in the sheet-like composition of the present invention is not particularly limited, it is 0.1 with respect to 100 parts by weight of the total content of the component (A) and the component (B). Is preferably 10 to 10 parts by weight, and more preferably 0.3 to 2 parts by weight. There exists a tendency for the adhesiveness of hardened | cured material to improve more by making content into 0.1 weight part or more. On the other hand, by setting the content to 10 parts by weight or less, there is a tendency that problems caused by outgas derived from the silane coupling agent do not easily occur.

  The sheet-like composition of the present invention may contain a conductive material as described above for the purpose of imparting conductivity to the cured product. As such an electroconductive material, the electroconductive fiber covering particle | grains demonstrated below are preferable especially from a viewpoint of coexistence of electroconductivity and transparency of hardened | cured material.

(Conductive fiber coated particles)
The conductive fiber-coated particle is a conductive fiber-coated particle including a particulate material and a fibrous conductive material that coats the particulate material (sometimes referred to herein as “conductive fiber”). It is. “Coating” in the conductive fiber-coated particles means a state in which the conductive fibers cover part or all of the surface of the particulate material. In the conductive fiber-coated particles, it is only necessary that the conductive fibers cover at least a part of the surface of the particulate matter. For example, there are more uncovered portions than covered portions. Also good. In the conductive fiber-coated particles, the particulate matter and the conductive fiber are not necessarily in contact with each other, but usually a part of the conductive fiber is in contact with the surface of the particulate matter.

  FIG. 1 is an example of a scanning electron microscope image of conductive fiber-coated particles. As shown in FIG. 1, the conductive fiber-coated particles have a configuration in which at least a part of the particulate matter (the true spherical substance in FIG. 1) is covered with the conductive fiber (the fibrous substance in FIG. 1). .

(Particulate matter)
The particulate matter constituting the conductive fiber-coated particles is a particulate structure.

  The material (raw material) constituting the particulate matter is not particularly limited, and examples thereof include known or commonly used materials such as metal, plastic, rubber, ceramic, glass, and silica. Among them, it is preferable to use a transparent material such as transparent plastic, glass, and silica, and it is particularly preferable to use a transparent plastic.

  The transparent plastic includes a thermosetting resin and a thermoplastic resin. Examples of thermosetting resins include poly (meth) acrylate resins; polystyrene resins; polycarbonate resins; polyester resins; polyurethane resins; epoxy resins; polysulfone resins; non-crystalline polyolefin resins: divinylbenzene, hexatriene, divinyl ether, divinyl. Sulfone, diallyl carbinol, alkylene diacrylate, oligo or polyalkylene glycol diacrylate, oligo or polyalkylene glycol dimethacrylate, alkylene triacrylate, alkylene tetraacrylate, alkylene trimethacrylate, alkylene tetramethacrylate, alkylene bisacrylamide, alkylene bismethacrylamide Polyfunctional monomers such as both-end acrylic modified polybutadiene oligomers alone The network polymer obtained by polymerizing with other monomers; phenol-formaldehyde resins, melamine formaldehyde resins, benzoguanamine formaldehyde resins, urea-formaldehyde resins. Examples of the thermoplastic resin include ethylene / vinyl acetate copolymer, ethylene / vinyl acetate / unsaturated carboxylic acid copolymer, ethylene / ethyl acrylate copolymer, ethylene / methyl methacrylate copolymer, ethylene / acrylic acid copolymer. Polymer, ethylene / methacrylic acid copolymer, ethylene / maleic anhydride copolymer, ethylene / aminoalkyl methacrylate copolymer, ethylene / vinyl silane copolymer, ethylene / glycidyl methacrylate copolymer, ethylene / hydroxyethyl methacrylate copolymer Examples thereof include a polymer, methyl (meth) acrylate / styrene copolymer, and acrylonitrile / styrene copolymer.

  The shape of the particulate matter is not particularly limited. For example, it is spherical (true spherical, substantially true spherical, elliptical spherical, etc.), polyhedral, rod-like (cylindrical, prismatic, etc.), flat, flake, indefinite Examples include shape. In the present invention, in particular, the conductive fiber-coated particles can be produced with high productivity, can be easily dispersed uniformly in the sheet-like composition, and can be easily given conductivity to the entire cured product. Is preferable, and a spherical shape is particularly preferable.

  The average particle diameter of the particulate material is not particularly limited, but is preferably 0.1 to 100 μm, more preferably 1 to 50 μm, and still more preferably 5 to 30 μm. When the average particle diameter is below the above range, it may be difficult to develop excellent conductivity by blending a small amount of conductive fiber-coated particles. If the average particle diameter exceeds the above range, the average particle diameter may be larger than the thickness of the sheet-shaped composition, and it tends to be difficult to obtain a sheet-shaped composition having a uniform thickness. In addition, the average particle diameter of the particulate matter is a median diameter (d50) by a laser diffraction / scattering method.

  The particulate material is preferably transparent. Specifically, the total light transmittance in the visible light wavelength region of the particulate matter is not particularly limited, but is preferably 70% or more, and more preferably 80% or more. When the total light transmittance is below the above range, the transparency of the cured product (including the conductive fiber-coated particles) may be lowered. In addition, the total light transmittance in the visible light wavelength region of the particulate matter is obtained by polymerizing the monomer that is the raw material of the particulate matter in a temperature range of 80 to 150 ° C. between glasses to obtain a flat plate having a thickness of 1 mm, It is obtained by measuring the total light transmittance in the visible light wavelength region of the flat plate in accordance with JIS K7361-1.

The particulate matter preferably has flexibility, and the 10% compressive strength of each particle is, for example, 10 kgf / mm ² or less, preferably 5 kgf / mm ² or less, particularly preferably 3 kgf / mm ² or less. The conductive fiber-coated particles containing particulate matter having a 10% compressive strength in the above range can be deformed following a fine concavo-convex structure by applying pressure. For this reason, even when the sheet-like composition containing the conductive fiber-coated particles is cured in a shape having a fine concavo-convex structure, the particulate matter can be distributed in detail, Can be prevented from occurring.

  The refractive index of the particulate material is not particularly limited, but is preferably 1.4 to 2.7, more preferably 1.5 to 1.8. The refractive index of the particulate matter is such that when the particulate matter is a plastic particle, the monomer that is the raw material of the particulate matter is polymerized in a temperature range of 80 to 150 ° C. between the glasses, and the length is 20 mm × width A 6 mm test piece was cut out, and a multi-wavelength Abbe refractometer (trade name “DR-M2”, manufactured by Atago Co., Ltd.) was used in a state where the prism and the test piece were in close contact using monobromonaphthalene as an intermediate solution. Can be obtained by measuring the refractive index at 20 ° C. at the sodium D line.

The particulate matter preferably has a small difference in refractive index (refractive index at 25 ° C., wavelength 589.3 nm) from the cured product of the sheet-like composition, and the particulate matter constituting the conductive fiber-coated particles. The absolute value of the difference in refractive index between the cured product of the sheet-like composition is preferably 0.1 or less (more preferably 0.05 or less, and still more preferably 0.02 or less).
That is, it is preferable that the refractive index of the cured product of the sheet-like composition of the present invention and the refractive index of the particulate material constituting the conductive fiber-coated particles satisfy the following formula.
| Refractive index of particulate matter-refractive index of cured product of sheet-like composition | ≦ 0.1

  By setting the difference in refractive index between the particulate matter constituting the conductive fiber-coated particles and the cured product of the sheet-like composition within the above range, the transparency is excellent and the haze is, for example, 10% or less (preferably 6% or less, further A cured product having a total light transmittance of 90% or more (preferably 93% or more) can be obtained. In addition, the haze of the hardened | cured material of the sheet-like composition of this invention can be measured based on JISK7136. Moreover, the total light transmittance (thickness: 10 μm, wavelength: 450 nm) in the visible light wavelength region of the cured product of the sheet-like composition of the present invention can be measured in accordance with JIS K7361-1, and glass is used. The measured value is taken as 100%, which is blank.

  Furthermore, the particulate matter constituting the conductive fiber-coated particles has a sharp particle size distribution (= small variation in particle diameter), and can provide excellent conductivity with a smaller amount of use. The coefficient of variation (CV value) is preferably 50 or less. The coefficient of variation is a value obtained by dividing the standard deviation by the average particle diameter (median diameter on a volume basis), and is a value that serves as an index of particle size uniformity.

  The particulate matter can be produced by a known or conventional method, and the production method is not particularly limited. For example, in the case of metal particles, it can be produced by a vapor phase method such as a CVD method or a spray pyrolysis method, a wet method using a chemical reduction reaction, or the like. In the case of plastic particles, for example, a method of polymerizing monomers constituting the resin (polymer) exemplified above by a known polymerization method such as a suspension polymerization method, an emulsion polymerization method, a seed polymerization method, or a dispersion polymerization method. Etc. can be manufactured.

  A commercial item can also be used as said particulate matter. Examples of particulate substances made of thermosetting resins include trade names “Techpolymer MBX Series”, “Techpolymer BMX Series”, “Techpolymer ABX Series”, “Techpolymer ARX Series”, and “Techpolymer AFX Series”. (Sekisui Chemicals Co., Ltd.), "Micropearl SP", "Micropearl SI" (Sekisui Chemical Co., Ltd.), etc. can be used. For example, the product name “Soft Bead” (manufactured by Sumitomo Seika Co., Ltd.), the product name “Duo Master” (manufactured by Sekisui Plastics Co., Ltd.), etc. are used as the particulate material made of thermoplastic resin. Can do.

(Fibrous conductive material (conductive fiber))
The conductive fibers constituting the conductive fiber-coated particles are conductive fibrous structures (linear structures). The shape of the conductive fiber is not particularly limited as long as it is fibrous (fibrous), but the average aspect ratio is preferably 10 or more (for example, 20 to 5000), particularly preferably 50 to 3000, and most preferably. Is 100-1000. When the average aspect ratio is less than the above range, it may be difficult to develop excellent conductivity by blending a small amount of conductive fiber-coated particles. The average aspect ratio of the conductive fibers is an electron with respect to a sufficient number (for example, 100 or more, preferably 300 or more; in particular, 100 or 300) of particulate matter using an electron microscope (SEM, TEM). It can be measured by taking a microscopic image, measuring the aspect ratio of these particulate materials, and arithmetically averaging them. The concept of “fibrous” in the conductive fiber includes shapes of various linear structures such as “wire” and “rod”. In the present specification, fibers having an average thickness of 1000 nm or less may be referred to as “nanowires”.

  Although the average thickness (average diameter) of the said conductive fiber is not specifically limited, 1-400 nm is preferable, More preferably, it is 10-200 nm, More preferably, it is 50-150 nm. When the average thickness is less than the above range, the conductive fibers are likely to aggregate and it may be difficult to produce the conductive fiber-coated particles. On the other hand, if the average thickness exceeds the above range, it may be difficult to coat the particulate matter, and it may be difficult to obtain conductive fiber-coated particles efficiently. The average thickness of the conductive fibers is an electron with respect to a sufficient number of conductive fibers (for example, 100 or more, preferably 300 or more; in particular, 100 or 300) using an electron microscope (SEM, TEM). It is calculated | required by image | photographing a microscope image, measuring the thickness (diameter) of these electroconductive fibers, and carrying out arithmetic average.

Although the average length of the said conductive fiber is not specifically limited, 1-100 micrometers is preferable, More preferably, it is 5-80 micrometers, More preferably, it is 10-50 micrometers. If the average length is less than the above range, it may be difficult to coat the particulate matter, and it may not be possible to obtain conductive fiber-coated particles efficiently. On the other hand, if the average length exceeds the above range, the conductive fibers are easily entangled. The average length of the conductive fibers is an electron for a sufficient number of conductive fibers (for example, 100 or more, preferably 300 or more; in particular, 100 or 300) using an electron microscope (SEM, TEM). It is calculated | required by image | photographing a microscope image, measuring the length of these electroconductive fibers, and carrying out arithmetic average. Note that the length of the conductive fiber should be measured in a linearly stretched state, but in reality it is often bent, so the conductive fiber can be measured using an image analyzer from an electron microscope image. The projected diameter and projected area are calculated and calculated from the following equation assuming a cylindrical body.
Length = projected area / projected diameter

  The material (raw material) which comprises the said conductive fiber should just be a raw material which has electroconductivity, for example, a metal, a semiconductor, a carbon material, a conductive polymer, etc. are mentioned.

  Examples of the metal include known or commonly used metals such as gold, silver, copper, iron, nickel, cobalt, tin, and alloys thereof. Among these, silver is preferable in terms of excellent conductivity.

  Examples of the semiconductor include known or commonly used semiconductors such as cadmium sulfide and cadmium selenide.

  As said carbon material, well-known thru | or usual carbon materials, such as carbon fiber and a carbon nanotube, are mentioned, for example.

  Examples of the conductive polymer include polyacetylene, polyacene, polyparaphenylene, polyparaphenylene vinylene, polypyrrole, polyaniline, polythiophene, and derivatives thereof (for example, an alkyl group, a hydroxy group, a carboxy group, a common polymer skeleton, Those having a substituent such as ethylenedioxy group; specifically, polyethylenedioxythiophene and the like). Of these, polyacetylene, polyaniline and derivatives thereof, polypyrrole and derivatives thereof, and polythiophene and derivatives thereof are preferable. The conductive polymer may contain a known or commonly used dopant (for example, an acceptor such as a halogen, a halide, or a Lewis acid; a donor such as an alkali metal or an alkaline earth metal).

  The conductive fiber is preferably a conductive nanowire, particularly at least one type of conductive nanowire selected from the group consisting of metal nanowires, semiconductor nanowires, carbon fibers, carbon nanotubes, and conductive polymer nanowires. Silver nanowires are most preferable because of their excellent conductivity.

  The conductive fiber can be produced by a known or conventional production method. For example, the metal nanowire can be manufactured by a liquid phase method, a gas phase method, or the like. More specifically, silver nanowires are, for example, Mater. Chem. Phys. 2009, 114, p333-338, Adv. Mater. 2002, 14, p833-837, Chem. Mater. 2002, 14, p4736-4745. It can be produced by the method described in JP-T-2009-505358. In addition, the gold nanowire can be manufactured, for example, by the method described in JP-A-2006-233252. Moreover, a copper nanowire can be manufactured by the method as described in Unexamined-Japanese-Patent No. 2002-266007, for example. Moreover, cobalt nanowire can be manufactured by the method as described in Unexamined-Japanese-Patent No. 2004-148771, for example. Furthermore, a semiconductor nanowire can be manufactured by the method as described in Unexamined-Japanese-Patent No. 2010-208925, for example. The carbon fiber can be produced, for example, by the method described in JP-A-06-081223. Carbon nanotubes can be produced, for example, by the method described in JP-A-06-157016. Conductive polymer nanowires can be produced, for example, by the methods described in JP-A-2006-241334 and JP-A-2010-76044. Commercially available products can be used as the conductive fibers.

The conductive fiber-coated particles can be produced by mixing the above-mentioned particulate material and conductive fibers in a solvent. Specific examples of the method for producing the conductive fiber-coated particles include the following methods (1) to (4).
(1) Mixing a dispersion in which the particulate matter is dispersed in a solvent (referred to as “particle dispersion”) and a dispersion in which the conductive fibers are dispersed in a solvent (referred to as “fiber dispersion”). Then, if necessary, the solvent is removed to obtain conductive fiber-coated particles (or a dispersion of the conductive fiber-coated particles).
(2) After blending and mixing the conductive fibers in the particle dispersion, the solvent is removed as necessary to obtain conductive fiber-coated particles (or a dispersion of the conductive fiber-coated particles).
(3) After mixing and mixing the particulate matter in the fiber dispersion, the solvent is removed as necessary to obtain conductive fiber-coated particles (or a dispersion of the conductive fiber-coated particles).
(4) After mixing and mixing the particulate matter and the conductive fibers in a solvent, the solvent is removed as necessary to obtain conductive fiber-coated particles (or a dispersion of the conductive fiber-coated particles). obtain.

  Examples of the solvent used in producing the conductive fiber-coated particles include water; alcohols such as methanol, ethanol, propanol, isopropanol, and butanol; ketones such as acetone, methyl ethyl ketone (MEK), and methyl isobutyl ketone (MIBK). Aromatic hydrocarbons such as benzene, toluene, xylene and ethylbenzene; ethers such as diethyl ether, dimethoxyethane, tetrahydrofuran and dioxane; esters such as methyl acetate, ethyl acetate, isopropyl acetate and butyl acetate; N, N-dimethylformamide; Amides such as N, N-dimethylacetamide; nitriles such as acetonitrile, propionitrile, and benzonitrile. These can be used individually by 1 type or in combination of 2 or more types (that is, as a mixed solvent). Of these, alcohol and ketone are preferable.

  Although the viscosity of the said solvent is not specifically limited, The viscosity in 25 degreeC is 10 mPa * s or less (for example, 0.1-10 mPa * s) at the point which can manufacture electroconductive fiber covering particle | grains efficiently. It is preferably 0.5 to 5 mPa · s. The viscosity of the solvent at 25 ° C. can be measured using, for example, an E-type viscometer (trade name “VISCONIC”, manufactured by Tokimec Co., Ltd.) (rotor: 1 ° 34 ′ × R24, rotation speed: 0.5 rpm, measurement temperature: 25 ° C.).

  The boiling point of the solvent at 1 atm is preferably 200 ° C. or less, particularly preferably 150 ° C. or less, and most preferably 120 ° C. or less, from the viewpoint that the conductive fiber-coated particles can be efficiently produced.

  The content of the particulate matter when mixing the particulate matter and the conductive fiber in the solvent is, for example, about 0.1 to 50 parts by weight, preferably 1 to 30 parts by weight with respect to 100 parts by weight of the solvent. It is. By controlling the content of the particulate matter within the above range, the conductive fiber-coated particles can be generated more efficiently.

  The content of the conductive fiber when mixing the particulate matter and the conductive fiber in the solvent is, for example, about 0.1 to 50 parts by weight, preferably 1 to 30 parts by weight with respect to 100 parts by weight of the solvent. It is. By controlling the content of the conductive fiber within the above range, the conductive fiber-coated particles can be generated more efficiently.

  The ratio of the particulate matter and the conductive fiber when mixing the particulate matter and the conductive fiber in the solvent is the ratio of the surface area of the particulate matter to the projected area of the conductive fiber [surface area / projected area]. However, it is preferable that the ratio is, for example, about 100/1 to 100/100, preferably 100/10 to 100/50. By controlling the ratio within the above range, the conductive fiber-coated particles can be generated more efficiently. In addition, the surface area of the said particulate matter is calculated | required by the method of multiplying the specific surface area calculated | required by BET method (based on JISZ8830) by the mass (usage amount) of a particulate matter. Further, as described above, the projected area of the conductive fibers is a sufficient number (for example, 100 or more, preferably 300 or more; in particular, 100 or 300) using an electron microscope (SEM, TEM). This is obtained by taking an electron microscope image of the conductive fibers, calculating the projected area of these conductive fibers using an image analyzer, and calculating the arithmetic average.

  After mixing the particulate matter and the conductive fibers, the conductive fiber-coated particles can be obtained as a solid by removing the solvent. The removal of the solvent is not particularly limited, and can be performed by a known or conventional method such as heating, distillation under reduced pressure, or the like. In addition, it is not always necessary to remove the solvent. For example, the solvent can be used as it is as a dispersion of conductive fiber-coated particles.

  As described above, the conductive fiber-coated particles can be produced by mixing raw materials (particulate matter and conductive fibers) in a solvent, and do not require a complicated process. It is advantageous.

  Particularly, as a combination of the particulate matter and the conductive fiber, the particulate matter having an average particle diameter A [μm] and an average length A × 0.5 [μm] or more (preferably A × 1.0 [μm] or more, By using conductive fibers of A × 1.5 [μm] or more most preferably, conductive fiber-coated particles can be produced more efficiently. In particular, in the case of a spherical or substantially spherical particulate material, a particulate material having an average circumference B [μm] and an average length (B × 1/6) [μm] or more (preferably B [μm It is preferable to use the above-mentioned conductive fibers. The average perimeter of the particulate matter is a sufficient number (for example, 100 or more, preferably 300 or more; in particular, 100, 300, etc.) using an electron microscope (SEM, TEM). It is obtained by taking an electron microscope image of the substance, measuring the circumference of these particulate substances, and calculating the arithmetic average.

  The ratio of the particulate matter and the conductive fiber constituting the conductive fiber-coated particle is such that the ratio of the surface area of the particulate matter to the projected area of the conductive fiber [surface area / projected area] is, for example, 100/1 to 100/100. It is preferable that the ratio is in a range (particularly 100/10 to 100/50) in that the conductivity can be imparted more efficiently while ensuring the transparency of the cured product. In addition, the surface area of the particulate matter and the projected area of the conductive fiber are each determined by the above-described method.

  Since the conductive fiber-coated particles have the above-described configuration, by adding a small amount to the sheet composition, excellent conductivity (particularly, conductivity in the thickness direction) can be imparted to the cured product, and the transparent A cured product having excellent properties and conductivity can be formed.

When the conductive fiber-coated particles have flexibility (for example, when the 10% compressive strength is 3 kgf / mm ² or less), the sheet-like composition containing the conductive fiber-coated particles is shaped to have fine irregularities. When the conductive fiber-coated particles are deformed to follow the uneven structure and reach the details when they are molded into, it is possible to prevent the occurrence of a portion with poor conductivity, and a cured product with excellent conductive performance. Can be formed.

  The content (blending amount) of the particulate matter (particulate matter contained in the conductive fiber-coated fine particles) in the sheet-like composition of the present invention is not particularly limited, but is based on the sheet-like composition (100% by weight). 0.09 to 6.0% by weight is preferable, more preferably 0.1 to 4.0% by weight, still more preferably 0.3 to 3.5% by weight, and still more preferably 0.3 to 3.0%. % By weight, particularly preferably 0.3 to 2.5% by weight, most preferably 0.5 to 2.0% by weight. When content of the said particulate matter is less than the said range, depending on a use, the electroconductivity of the obtained hardened | cured material may become inadequate. On the other hand, if the content of the particulate matter exceeds the above range, the resulting cured product may have insufficient transparency depending on the application.

  The content of the particulate matter in the sheet-like composition of the present invention is not particularly limited, but is preferably about 0.02 to 7% by volume, more preferably 0 with respect to the sheet-like composition (100% by volume). 0.1 to 5% by volume, more preferably 0.3 to 3% by volume, and particularly preferably 0.4 to 2% by volume.

  The content (blending amount) of the conductive fiber in the sheet-like composition of the present invention is not particularly limited, but is preferably about 0.01 to 1.0% by weight with respect to the sheet-like composition (100% by weight). More preferably 0.02 to 0.8% by weight, still more preferably 0.03 to 0.6% by weight, particularly preferably 0.03 to 0.4% by weight, and most preferably 0.03 to 0.2% by weight. % By weight. When content of the said conductive fiber is less than the said range, depending on a use, the electroconductivity of the obtained hardened | cured material may become inadequate. On the other hand, if the content of the conductive fiber exceeds the above range, the resulting cured product may have insufficient transparency depending on the application.

  Although content of the said conductive fiber in the sheet-like composition of this invention is not specifically limited, 0.01-1.1 volume% is preferable with respect to a sheet-like composition (100 volume%), More preferably It is 0.02-0.9 volume%, More preferably, it is 0.03-0.7 volume%, Most preferably, it is 0.03-0.4 volume%.

  The sheet-like composition of the present invention can be produced by a known or conventional sheet or film production method, and is not particularly limited. For example, the epoxy resin (A), the alicyclic epoxy compound (B), The sheet-like composition of the present invention is prepared by mixing the photocationic polymerization initiator (C) and, if necessary, the curing retarder (D) and other components in a solvent and uniformly dispersing or dissolving them. Can be produced by preparing a precursor (usually a dispersion or solution), applying it on a suitable substrate such as a release film, and then removing the solvent by drying or the like. . In mixing the respective components constituting the sheet-like composition of the present invention, known or conventional means such as a rotation / revolution mixer, a planetary mixer, a kneader, or a dissolver can be used. Examples of the solvent used for mixing each component include ketones (eg, acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, etc.); ethers (eg, dioxane, tetrahydrofuran, etc.); aliphatic hydrocarbons (eg, hexane, etc.). Alicyclic hydrocarbons [eg cyclohexane etc.]; aromatic hydrocarbons [eg benzene, toluene, xylene etc.]; halogenated hydrocarbons [eg dichloromethane, dichloroethane etc.]; esters [eg methyl acetate, acetic acid Ethyl etc.]; alcohol [eg methanol, ethanol, isopropanol, butanol, cyclohexanol etc.]; cellosolves [eg methyl cellosolve, ethyl cellosolve etc.]; cellosolve acetates; amide [eg dimethylform Bromide, dimethyl acetamide, etc.] and the like. In addition, a solvent can also be used individually by 1 type and can also be used in combination of 2 or more type. Among these, ketones are preferred because they are excellent in solubility and handling properties of the components of the sheet-like composition of the present invention. The amount of the solvent used can be appropriately selected and is not particularly limited.

  In addition, the sheet-like composition of this invention can be manufactured also by the method (for example, melt film-forming method) which does not use a solvent.

  The sheet-like composition of the present invention may have a single layer structure or a multilayer (multilayer) structure. When the sheet-like composition of the present invention has a multilayer structure, it can be produced by a known or commonly used method for producing a laminated sheet or laminated film.

  Although the thickness (total thickness) of the sheet-like composition of the present invention is not particularly limited, it is preferably 1 to 100 μm, more preferably 2 to 80 μm, and further preferably 5 to 50 μm. By setting the thickness in the above range, handling is easy, and it is possible to efficiently prevent water vapor from entering the cured product, and it can be preferably used particularly as a sealing sheet for organic EL elements. There is.

  Although the glass transition temperature of the sheet-like composition of this invention should just be 30-90 degreeC, it is not specifically limited, 35-70 degreeC is preferable, More preferably, it is 40-60 degreeC. Since the glass transition temperature is 90 ° C. or lower, it can be melted by heating at a relatively low temperature, so that it is particularly preferably used in applications where heating at high temperatures cannot be performed (especially for sealing organic EL elements). it can. On the other hand, when the glass transition temperature is 30 ° C. or higher, the release film can be easily peeled off and the handling and operability are further improved, and the productivity of electronic devices such as organic EL devices is further improved. To do. In addition, the glass transition temperature of the sheet-like composition of the present invention is measured using a differential scanning calorimeter in a nitrogen stream under a measurement temperature range of −50 to 180 ° C. and a temperature rising rate of 20 ° C./min.

The glass transition temperature of the sheet-like composition of the present invention when the sheet-like composition is irradiated with 1000 mJ / cm ² of ultraviolet rays is not particularly limited, but is preferably 30 to 90 ° C, more preferably 35 to 70 ° C. More preferably, it is 40-65 degreeC. When the glass transition temperature is 90 ° C. or lower, it can be melted by heating at a relatively low temperature, and therefore particularly preferable in applications where heating at a high temperature cannot be performed (especially for sealing organic EL elements). There is a tendency to be usable. On the other hand, when the glass transition temperature is 30 ° C. or higher, the release film can be easily peeled off and the handling and operability are further improved, and the productivity of electronic devices such as organic EL devices is more improved. There is a tendency to improve. In addition, the glass transition temperature at the time of irradiating 1000 mJ / cm < ² > of the sheet-like composition of the present invention is within 30 minutes after irradiating the sheet-shaped composition of the present invention with 1000 mJ / cm < ² > ( A sheet-like composition) is used as a sample, and is measured using a differential scanning calorimeter in a nitrogen stream under a measurement temperature range of −50 to 180 ° C. and a temperature increase rate of 20 ° C./min.

  The haze of the sheet-like composition of the present invention is not particularly limited, but is preferably 2% or less, more preferably 1.5% or less, and further preferably 1.2% or less. The lower limit of haze is not particularly limited, and is most preferably 0%, but is generally 0.1% or more. By setting the haze to 2% or less, the cured product has very excellent transparency, and thus can be preferably used as a sealing sheet for organic EL elements and optical semiconductor elements. In addition, the haze of the sheet-like composition of the present invention is measured by a method based on JIS K7136. More specifically, measurement can be performed using a D65 fluorescent lamp as a light source and a haze meter.

  The total light transmittance in the visible light wavelength region of the sheet-like composition of the present invention is not particularly limited, but is preferably 85% or more, more preferably 90% or more. The upper limit of the total light transmittance is not particularly limited, and is most preferably 100%, but generally 99% or less. By setting the total light transmittance to 85% or more, the cured product has very excellent transparency, and thus can be preferably used particularly as a sealing sheet for organic EL elements and optical semiconductor elements. In addition, the said total light transmittance of the sheet-like composition of this invention is measured by the method based on JISK7361-1. More specifically, measurement can be performed using a D65 fluorescent lamp as a light source and a haze meter.

  The glass transition temperature, haze, and total light transmittance of the sheet-like composition of the present invention are, in particular, the content of the epoxy resin (A), the content of the alicyclic epoxy compound (B), and the epoxy resin (A). The ratio of the alicyclic epoxy compound (B), the ratio of the total amount of the epoxy resin (A) and the alicyclic epoxy compound (B) to the total amount of the sheet-like composition or the cationic curable compound, the curing retarder (D) By adjusting the use and the content thereof to the above range, the above range can be efficiently controlled.

The sheet-like composition of the present invention can be cured by light irradiation and subsequent heating. The light irradiation conditions are not particularly limited and can be appropriately selected. For example, when the thickness of the sheet-like composition is 100 μm, it is preferable to irradiate light of 500 mJ / cm ² or more with a mercury lamp or the like. Moreover, the heating after light irradiation is not particularly limited, but for example, at 40 to 150 ° C. (particularly preferably 60 to 120 ° C., most preferably 80 to 110 ° C.) for 10 to 200 minutes (particularly preferably) using an oven or the like. It is preferable to heat for 30 to 120 minutes.

Although the sheet-like composition of the present invention is not particularly limited, the absolute value of the curing shrinkage rate when it is cured by irradiation at 100 ° C. for 30 minutes after irradiation with 1000 mJ / cm ² ultraviolet rays is 1% or less ( For example, 0.01 to 1%) is preferable. When the curing shrinkage rate is 1% or less, stress hardly remains in the cured product, and there is a tendency that problems are not likely to occur in the semiconductor device (organic EL device or the like). The cure shrinkage can be measured by a specific gravity method.

The sheet-like composition of the present invention is not particularly limited, but it allows water vapor permeation of a cured product (thickness: 100 μm) obtained by irradiating with 1000 mJ / cm ² of ultraviolet rays and then curing by heating at 100 ° C. for 30 minutes. The rate is preferably 50 (g / m ² · day) or less, more preferably 45 (g / m ² · day) or less. When the water vapor transmission rate is 50 (g / m ² · day) or less, the semiconductor element can be sufficiently protected from moisture, and the quality and durability of the semiconductor device tend to be further improved. The water vapor transmission rate can be calculated by measuring the moisture permeation amount of a cured product adjusted to a thickness of 100 μm in accordance with JIS L 1099 and JIS Z 0208 under the conditions of 60 ° C. and 90% RH. it can.

  Further, when the sheet-like composition of the present invention contains a curing retarder (D), the amount of outgas derived from the curing retarder (D) of the cured product (60 mg) is not particularly limited, but is 90 ppm or less (preferably 70 ppm). Hereinafter, 50 ppm or less is particularly preferable. In particular, by using the azole compound as the curing retarder (D), the outgas can be efficiently controlled within the above range. The outgas amount can be measured by the head space GC / MS.

  Moreover, when the sheet-like composition of this invention contains the said electroconductive fiber coating particle, the hardened | cured material obtained by hardening | curing it is excellent in electroconductivity, and an electrical resistivity (at 25 degreeC and 1 atmosphere) is 0. It is about 1Ω · cm to 10MΩ · cm, preferably 0.1Ω · cm to 1MΩ · cm.

  Although the haze of the hardened | cured material of the sheet-like composition of this invention is not specifically limited, 2% or less is preferable, More preferably, it is 1.5% or less, More preferably, it is 1.2% or less. The lower limit of haze is not particularly limited, and is most preferably 0%, but is generally 0.1% or more. When the haze is 2% or less, it can be preferably used as a sealing material for organic EL devices and optical semiconductor devices. In addition, the haze of hardened | cured material is measured by the method based on JISK7136. More specifically, measurement can be performed using a D65 fluorescent lamp as a light source and a haze meter.

  Although the total light transmittance in the visible light wavelength region of the cured product of the sheet-like composition of the present invention is not particularly limited, it is preferably 85% or more, more preferably 90% or more. The upper limit of the total light transmittance is not particularly limited, and is most preferably 100%, but generally 99% or less. When the total light transmittance is 85% or more, it can be preferably used as a sealing material for organic EL elements and optical semiconductor elements. In addition, the said total light transmittance of hardened | cured material is measured by the method based on JISK7361-1. More specifically, measurement can be performed using a D65 fluorescent lamp as a light source and a haze meter.

  The shape in the surface direction of the sheet-like composition of the present invention is not particularly limited, and can be appropriately set depending on the application. Moreover, when the sheet-like composition of the present invention has a long shape, it may be wound in a roll shape or may not be wound. When the sheet-shaped composition of the present invention is a wound body wound in a roll shape, for example, a process using the sheet-shaped composition (for example, an organic EL element sealing process) is rolled to Since it may be implemented with a roll, it is preferable.

  The surface of the sheet-like composition of the present invention may be protected by a protective film such as a release film (release liner) until use. As the protective film, a known or conventional protective film can be used.

  The sheet-shaped composition of the present invention can be converted into a cured product by curing, specifically, by proceeding and curing the polymerization reaction of the cationic curable compound in the sheet-shaped composition. The sheet-like composition of the present invention includes various elements (semiconductor elements, optical semiconductor elements, organic EL devices) in electronic devices such as organic EL devices, light-emitting diode devices, displays (for example, liquid crystal display devices and touch panels), and electronic paper. It can be preferably used as a sealing sheet (sealing sheet for electronic devices) for sealing elements and the like. Especially, since the sheet-like composition of the present invention can be cured at a relatively low temperature and has a small volume change upon curing, it is particularly used as an organic EL element sealing sheet (an organic EL device sealing sheet). It can be preferably used. Since the sheet-like composition of the present invention has a sheet-like shape and form, it has excellent handling properties and can be plasticized at a relatively low temperature, so that it can be sealed by lamination or bonding under mild conditions. Furthermore, since the sealing work by roll-to-roll is also possible, the efficiency of the sealing work can be remarkably improved, which greatly contributes to the improvement of the productivity of electronic devices such as organic EL devices.

  In particular, when the sheet-shaped composition of the present invention contains a curing retarder (D), the sheet-shaped composition of the present invention is not cured at the stage of irradiation with light (the curing reaction is delayed), but is plasticized by heating. The characteristics that can be achieved remain. The sheet-like composition of the present invention after this light irradiation is further heated (usually at a temperature higher than the temperature required for plasticization), so that the curing reaction proceeds and can be converted into a cured product. it can. The heating for causing the curing reaction to proceed usually requires a temperature higher than the temperature necessary for plasticization, but a relatively low temperature heating (for example, heating at 100 ° C. or lower) is sufficient. For this reason, for example, the sheet-shaped composition of the present invention is first irradiated with light, and then the light-irradiated sheet-shaped composition is laminated on the organic EL element formed on the substrate, and then compared. The organic EL element can be sealed by a process (for example, see FIG. 3 to be described later) in which the film is heated and cured at a low temperature. In such a process, the organic EL element is not irradiated with light for curing the sheet-like composition, and high-temperature heat is not applied, so that deterioration of the organic EL element due to sealing work is suppressed. Or can be prevented. For this reason, a high quality organic EL device can be obtained.

  In FIG. 2, the schematic (sectional drawing) explaining an example of the method of sealing an organic EL element using the sheet-like composition (sealing sheet) of this invention is shown. First, from the sheet-like composition 1 (FIG. 2 (a)) in which the surfaces on both sides are protected by the protective film 2, one protective film 2 is peeled off, and a glass substrate is formed on the exposed surface of the sheet-like composition 1. 3 are laminated and bonded together while heating to produce a laminate shown in FIG. Next, the remaining protective film 2 is peeled off from the laminate, and bonded to a glass substrate 3 having an organic EL element 4 formed on the surface, as shown in FIG. Then, a structure in which the organic EL element 4 is covered with the sheet-like composition 1 is obtained ((d) in FIG. 2). Then, light irradiation (ultraviolet irradiation) is performed ((e) of FIG. 2), and the sheet-like composition 1 is cured and converted into a cured product 5 by further heating, whereby 2 organic EL elements 4 are obtained. An organic EL device sealed with the cured product 5 between the glass substrates 3 is obtained ((f) in FIG. 2). Further, annealing or the like may be performed as necessary. Thus, the obtained organic EL device is an organic EL device which has an organic EL element and the sealing material which seals this organic EL element, Comprising: The said sealing material is a sheet-like composition of this invention. It is an organic EL device that is a cured product of the product.

  In FIG. 3, the schematic (sectional drawing) explaining another example of the method of sealing an organic EL element using the sheet-like composition (sealing sheet) of this invention is shown. As the sheet-like composition of the present invention in this method, one containing a curing retarder (D) is used. First, from the sheet-like composition 1 (FIG. 3 (a)) whose surfaces on both sides are protected by the protective film 2, one protective film 2 is peeled off, and a glass substrate is placed on the exposed surface of the sheet-like composition 1. 3 are superposed to produce a laminate shown in FIG. Next, light irradiation (particularly, ultraviolet irradiation) is performed from the glass substrate 3 side of the laminate (FIG. 3C). At this stage, the sheet-like composition 1 in the laminate is not cured and has thermoplasticity. Subsequently, the remaining protective film 2 is peeled off from the laminate, and bonded to a glass substrate 3 having an organic EL element 4 formed on the surface, as shown in FIG. Then, a structure in which the organic EL element 4 is covered with the sheet-like composition 1 after the light irradiation is obtained ((e) in FIG. 3). Thereafter, the sheet-shaped composition 1 after light irradiation by heating is cured and converted into a cured product 5, whereby the organic EL element 4 is sealed between the two glass substrates 3 with the cured product 5. An EL device is obtained ((f) in FIG. 3). Further, annealing or the like may be performed as necessary. Thus, the obtained organic EL device is an organic EL device which has an organic EL element and the sealing material which seals this organic EL element, Comprising: The said sealing material is a sheet-like composition of this invention. It is an organic EL device that is a cured product of the product. According to the method as shown in FIG. 3, the organic EL element is not exposed to light during curing in the sealing step, and high-temperature heat is not applied. A high organic EL device can be obtained.

  The method of sealing an organic EL element using the sheet-like composition of the present invention is not limited to the method shown in FIGS. 2 and 3 described above, and is a sealing method using a known or conventional sheet or film. Can be implemented.

<Laminate>
By laminating the sheet-shaped composition of the present invention and a sheet or film other than the sheet-shaped composition (sometimes referred to as “other sheets”), at least one of the sheet-shaped compositions of the present invention A laminate having a sheet is obtained. Examples of other sheets include known and commonly used sheets and films, and are not particularly limited. For example, the sheets are made of various materials such as paper, cloth, metal, semiconductor, ceramics, glass, plastic, and composite materials thereof. A sheet, a film, etc. are mentioned. In addition, as another sheet | seat, the thing of a single layer structure can also be used and what has a multilayer (lamination | stacking) structure can also be used. In addition, other sheets may be subjected to a known or common surface treatment. Further, when a plastic film or sheet is used as another sheet, the plastic film or sheet may be an unstretched film or sheet, or a stretched film or sheet (uniaxially stretched film or sheet, biaxially stretched). Film or sheet).

  In the above laminate, the other sheet may be laminated only on one surface of the sheet-like composition of the present invention, or may be laminated on both surfaces, but the laminate is sealed. When used as a sheet (especially a sealing sheet for an organic EL device), it is preferably laminated only on one surface of the sheet-like composition of the present invention.

  In the above laminate, the sheet-like composition of the present invention and other sheets may be laminated directly or via other layers (such as an adhesive layer). Moreover, when the said laminated body has two or more other sheets, these other sheets may be laminated | stacked directly, and may be laminated | stacked via other layers (adhesive layer etc.).

For example, as the other sheet in the laminate, a sheet having a very low water vapor permeability (including a film, the same applies hereinafter), for example, a sheet having a water vapor transmission rate of 10 ⁻³ g / m ² · day or less is used. Thus, a laminate that can be used as a sealing sheet having high water vapor barrier properties can be obtained. The sheet having a water vapor transmission rate of 10 ⁻³ g / m ² · day or less may have a single-layer configuration or a multilayer (multi-layer) configuration. As the sheet having a water vapor transmission rate of 10 ⁻³ g / m ² · day or less, a known or commonly used sheet can be used, and is not particularly limited. For example, a silicon oxynitride film (SiON film), a silicon nitride film (SiN film), silicon oxide film (SiO film), plastic film (for example, cyclic polyolefin film) having a vapor deposition film having a high water vapor barrier property on one or both surfaces, such as an aluminum oxide film (AlO film), etc. Can be mentioned. The thickness (total thickness) of the sheet having a water vapor transmission rate of 10 ⁻³ g / m ² · day or less is not particularly limited, but is preferably 10 to 1000 μm, and more preferably 40 to 500 μm.

  In addition to the sheet-like composition of the present invention and other sheets, the laminate may have other layers (for example, an undercoat layer, an intermediate layer, etc.) as long as the effects of the present invention are not impaired. Good.

FIG. 4 shows the laminate (sealing sheet; the sheet-like composition of the present invention, and a sheet having a water vapor transmission rate of 10 ⁻³ g / m ² · day or less on one surface of the sheet-like composition. The schematic diagram (sectional drawing) explaining an example of the method of sealing an organic EL element using the laminated body which has) is shown. First, the glass substrate 3 on which the protective film 2 is peeled from the laminate (FIG. 4A) whose surface on the sheet-like composition 1 side is protected by the protective film 2 and the organic EL element 4 is formed on the surface. Are bonded together as shown in FIG. Next, it is melt-laminated while heating to obtain a structure in which the organic EL element 4 is covered with the sheet-like composition 1 ((c) of FIG. 4). Then, light irradiation (for example, ultraviolet irradiation) is performed ((d) of FIG. 4), and the sheet-like composition 1 is hardened and further converted into a cured product 5 by further heating, whereby the organic EL element 4 is obtained. However, the organic EL device sealed with the cured product 5 between the glass substrate 3 and the sheet 6 having a water vapor transmission rate of 10 ⁻³ g / m ² · day or less is obtained ((e) in FIG. 4). Further, annealing by heating may be performed as necessary. Thus, the obtained organic EL device is an organic EL device which has an organic EL element and the sealing material which seals this organic EL element, Comprising: The said sealing material is a sheet-like composition of this invention. It is an organic EL device that is a cured product of a product (a sheet-like composition in the laminate). When the sheet-like composition in the laminate includes a curing retarder (D), the laminate is used to perform a sealing operation in a process in which light is not applied to the organic EL element as shown in FIG. be able to. In addition, the method of sealing an organic EL element using the said laminated body is not limited to these methods, It can be based on the sealing method using a well-known thru | or usual sheet | seat.

  The sheet-like composition of the present invention and the laminate having the sheet-like composition may be used, for example, as a sealing sheet (semiconductor device, light) other than an organic EL device, in addition to the use as a sealing sheet for the organic EL element described above. Semiconductor devices, electronic devices such as electronic paper, sealing sheets (sealing materials) in solar cells, lenses (high refractive index lenses), various refractive index adjustment layers (touch panels, etc.), light extraction layers, dark part bonding adhesion It can be preferably used as an agent (adhesive, sealing material) or the like.

  Hereinafter, the present invention will be described in more detail based on examples, but the present invention is not limited to these examples. In addition, the unit of the compounding ratio of the structural component of a sheet-like composition shown in Table 1 and a solvent (MEK) is a weight part.

Example 1
[Production of sheet-like composition]
90 parts by weight of a bisphenol F type epoxy resin (trade name “jER4256B45”, manufactured by Mitsubishi Chemical Corporation, weight average molecular weight 60000-80000), 10 parts by weight of 3,4,3 ′, 4′-diepoxybicyclohexyl, photocation 2 parts by weight of a polymerization initiator (diphenyl [4- (phenylthio) phenyl] sulfonium tris (pentafluoroethyl) trifluorophosphate) and 150 parts by weight of methyl ethyl ketone were stirred and mixed to obtain a mixed solution (composition solution).
The mixed solution was applied onto a release-treated PET film using an applicator so that the thickness after drying was 20 μm. After coating, the solvent was removed by heating and drying at 80 ° C. for 15 minutes with a warm air dryer to obtain a sheet-like composition having a thickness of 20 μm.

Examples 2 to 9, Comparative Examples 1 and 2
[Production of sheet-like composition]
A sheet-like composition having a thickness of 20 μm was obtained in the same manner as in Example 1 except that the composition of the mixed solution (components and solvent of the sheet-like composition) was changed as shown in Table 1.

In addition, the component used in manufacture of a sheet-like composition is as follows.
[Component (A)]
a-1: Trade name “jER4256B45” [Mitsubishi Chemical Corporation, bisphenol F type epoxy resin (weight average molecular weight 60000-80000)]
a-2: Trade name “jER4275” [Mitsubishi Chemical Corporation, copolymer of bisphenol A type epoxy resin and bisphenol F type epoxy resin (phenoxy resin, weight average molecular weight 60000)]
a-3: Trade name “jER1256B40” [Mitsubishi Chemical Corporation, bisphenol A type epoxy resin (weight average molecular weight 45000)]
[Component (B)]
b-1: 3,4,3 ′, 4′-diepoxybicyclohexyl b-2: trade name “Celoxide 2021P” [manufactured by Daicel Corporation, 3,4-epoxycyclohexylmethyl (3,4-epoxy) cyclohexane Carboxylate]
b-3: 2,3-bis (3,4-epoxycyclohexyl) oxirane b-4: trade name “Epolide GT401” [manufactured by Daicel Corporation, modified with tetra (3,4-epoxycyclohexylmethyl) butanetetracarboxylate ε-Caprolactone, Compound Represented by Formula (10)]
[Cation curable compound]
b-5: Trade name “Epicron EXA835LV” [manufactured by DIC Corporation, bisphenol F type epoxy resin, weight average molecular weight 350, epoxy equivalent 170 g / eq]
[Component (C)]
c-1: Diphenyl [4- (phenylthio) phenyl] sulfonium tris (pentafluoroethyl) trifluorophosphate [component (D)]
d-1: 3,5-dimethylpyrazole [solvent]
MEK: Methyl ethyl ketone

[Evaluation]
The following evaluation test was performed about the sheet-like composition obtained by the Example and the comparative example.

(1) Haze (after curing)
The sheet-like compositions obtained in Examples and Comparative Examples were irradiated with 1000 mJ / cm ² of ultraviolet rays and then cured by heating at 100 ° C. for 30 minutes to prepare a cured product having a thickness of 20 μm. The haze of the cured product was measured according to JIS K7136 method. Specifically, the haze of the cured product obtained above was measured using a haze meter NDH-5000W (manufactured by Nippon Denshoku Industries Co., Ltd.) using a D65 fluorescent lamp as a light source. The results are shown in the column of “Hz (after curing)” in Table 1.

(2) Total light transmittance (after curing)
The sheet-like compositions obtained in Examples and Comparative Examples were irradiated with 1000 mJ / cm ² of ultraviolet rays and then cured by heating at 100 ° C. for 30 minutes to prepare a cured product having a thickness of 20 μm. Measurement of the total light transmittance (total light transmittance in the visible light wavelength region) of the cured product was performed according to JIS K7361-1. Specifically, the total light transmittance of the cured product obtained above was measured using a haze meter NDH-5000W (manufactured by Nippon Denshoku Industries Co., Ltd.) using a D65 fluorescent lamp as a light source. The results are shown in the column of “Tt (after curing)” in Table 1.

(3) Glass transition temperature About the sheet-like compositions obtained in Examples and Comparative Examples, using a differential scanning calorimeter DSC Q2000 (manufactured by TA Instruments Japan Co., Ltd.), under a nitrogen stream The glass transition temperature was measured in the temperature range of −50 to 150 ° C. under the temperature rising rate of 20 ° C./min. The results are shown in the “Tg” column of Table 1.

(4) Glass transition temperature (after UV irradiation)
The sheet-like compositions obtained in Examples and Comparative Examples were irradiated with 1000 mJ / cm ² of ultraviolet rays using an ultraviolet irradiation device (Ushio Electric Co., Ltd., high pressure mercury lamp). About the sheet-like composition within 30 minutes after irradiating with ultraviolet rays, using a differential scanning calorimeter DSC Q2000 (manufactured by TA Instruments Japan Co., Ltd.), a heating rate of 20 under a nitrogen stream. The glass transition temperature (glass transition temperature of the sheet-like composition after irradiation with ultraviolet rays) was measured in the temperature range of −50 to 150 ° C. under the conditions of ° C./min. The results are shown in the column of “Tg (after UV irradiation)” in Table 1.

(5) Curing Shrinkage The curing shrinkage when the sheet-like compositions obtained in Examples and Comparative Examples were cured and converted into cured products was calculated by the specific gravity method. Specifically, the specific gravity (density before curing) of the sheet-shaped composition and the curing obtained by irradiating the sheet-shaped composition with ultraviolet rays of 1000 mJ / cm ² and heating at 100 ° C. for 30 minutes. The specific gravity (density after curing) of the product was measured with an electronic hydrometer SD-200L (manufactured by Mirage Trading Co., Ltd.), and the shrinkage rate of curing was calculated by the following formula using these values. The results are shown in the column of “curing shrinkage” in Table 1.
Calculation formula: Curing shrinkage rate (%) = (density before curing−density after curing) / (density before curing) × 100

(6) Water vapor transmission rate (WVTR)
The sheet-like compositions obtained in the examples and comparative examples were irradiated with 1000 mJ / cm ² of ultraviolet rays and then heated at 100 ° C. for 30 minutes to be cured to produce a cured product. Subsequently, this hardened | cured material was attached to the moisture-permeable cup, and the sample (sample for water vapor permeability measurement of hardened | cured material) was produced. Using the sample, the water vapor permeability of the cured products of the sheet-like compositions obtained in Examples and Comparative Examples was measured under the conditions of 60 ° C. and 90% RH in accordance with JIS L1099. The results are shown in the column of “WVTR (60 ° C. 90%)” in Table 1.

As shown in Table 1, all of the sheet-like compositions (Examples) of the present invention had a glass transition temperature of 30 ° C. or higher, could be handled as a sheet at room temperature, and were excellent in handling properties. In addition, all the sheet-like compositions of the present invention had a glass transition temperature of 90 ° C. or lower, and could be plasticized by heating at a relatively low temperature. Furthermore, any of the sheet-like compositions of the present invention had a small volume change upon curing, and all of the obtained cured products had low water vapor permeability and excellent moisture resistance. As described above, the sheet-like composition of the present invention has particularly preferable characteristics as a sealing sheet for sealing an organic EL element that is fragile to heat and moisture.
In particular, the sheet-like composition (Example 6) containing 3,5-dimethylpyrazole, which is a curing retarder, is not cured at the stage of irradiation with light, but can be plasticized by heating, and then at a relatively low temperature. Since it can be cured by heating with, it enables sealing by a process (for example, the process shown in FIG. 3) that does not expose the organic EL element to light during curing and high-temperature heat. It was a thing. The ability to seal the organic EL element by such a process has a great merit in terms of the quality of the organic EL device. In addition, the sealing operation using a solid sheet such as the sheet-like composition of the present invention is simple, and a roll-to-roll process can be adopted. Therefore, there is a great merit in terms of productivity of the organic EL element.
On the other hand, when the alicyclic epoxy compound (B) is not included (Comparative Example 1), the curing shrinkage ratio is large. For example, when used as a sealing sheet for an organic EL element, the curing is performed. There is a risk that problems due to residual stress of the material (peeling due to insufficient adhesion, etc.) may occur. Moreover, when it does not contain an alicyclic epoxy compound (B) and further contains a curing retarder (Comparative Example 2), it is presumed that the curing reaction has not progressed sufficiently, but the obtained curing is obtained. The product was extremely inferior in moisture resistance.

1: Sheet-like composition 2: Release film (protective film)
3: Glass substrate 4: Organic EL element 5: Cured product 6: Water vapor transmission rate of 10 ⁻³ g / m ² · day or less sheet L: UV lamp

Claims (5)

  A sheet-shaped composition comprising an epoxy resin (A) having a weight average molecular weight of 20,000 to 200,000, an alicyclic epoxy compound (B), and a photocationic polymerization initiator (C), and having a glass transition temperature. A sheet-like composition having a temperature of 30 to 90 ° C.   The content of the alicyclic epoxy compound (B) is 5 to 40% by weight with respect to the total amount (100% by weight) of the epoxy resin (A) and the alicyclic epoxy compound (B). A sheet-like composition.   Furthermore, the sheet-like composition of Claim 1 or 2 containing a hardening retarder (D).   The sheet-like composition according to any one of claims 1 to 3, wherein the alicyclic epoxy compound (B) is 3,4,3 ', 4'-diepoxybicyclohexyl.   It is a sealing sheet for electronic devices, The sheet-like composition of any one of Claims 1-4.