TWI651358B - Sealing material and hardened material - Google Patents

Abstract

An object of the present invention is to provide a sealing material which can form a sealing layer having a low moisture permeability and a moderately low modulus of elasticity, or a sealing layer having a small thickness. In order to solve the above problems, the present invention provides a sealing material comprising: a polymerizable monomer (B) having at least one radical polymerizable functional group per molecule, and having a molecular weight of 50 or more and 1,000 or less. It is liquid at 23 ° C; the anhydride derivative (C) contains at least one acid anhydride group and a radically polymerizable functional group constituting a five-membered or six-membered ring in each molecule; a radical polymerization initiator ( D) comprising at least one of a thermal radical polymerization initiator and a photoradical polymerization initiator.

Description

Sealing material and hardened material

The present invention relates to a sealing material and a cured product thereof.

An organic electroluminescence (EL) element has been used in displays, illumination devices, and the like because it consumes less power. Since the organic EL element is easily deteriorated by moisture or oxygen in the atmosphere, it is used by sealing with various sealing members.

The organic EL device may be, for example, a structure including a substrate, an organic EL element disposed on the substrate, and a sealing substrate paired with the substrate. An example of a method of sealing the organic EL element of such a structure is a method of applying a sealing material between a sealing substrate and a substrate, and between the organic EL element and the sealing substrate, and curing the surface (face sealing) law).

Further, in order to reduce the moisture permeability of the sealing layer containing the cured product of the sealing material, it was investigated to add a hygroscopic filler to the sealing material. Specifically, a sealing material containing calcium oxide particles (Patent Documents 1 to 3) or a sealing material containing porous ceria particles (Patent Document 4) and the like are proposed.

In addition, an organic metal compound is also known as a water-trapping agent, and a transparent film containing the above-described organometallic compound is also proposed (Patent Documents 5 to 7). Moreover, it has also been proposed to use organometallic compounds and powdered inorganic oxides as The moisture trapping agent is added to a hot-melt type member or the like (Patent Document 8).

On the other hand, a compound containing a radically polymerizable functional group and an acid anhydride group in a molecule is known as a difunctional monomer which reacts with an acrylic resin and an epoxy resin (Non-Patent Document 1). In addition, it has been known that a compound having an acid anhydride group and an acid group in one molecule is added to a composition for producing a curable resin (Patent Document 9).

Prior art literature

Patent literature

Patent Document 1: International Publication No. 2010/084939

Patent Document 2: Japanese Patent Laid-Open Publication No. 2005-122910

Patent Document 3: Japanese Patent Laid-Open Publication No. 2007-184279

Patent Document 4: Japanese Patent Laid-Open Publication No. 2007-284472

Patent Document 5: Japanese Patent Laid-Open Publication No. 2005-298598

Patent Document 6: Japanese Patent Laid-Open No. 2011-026521

Patent Document 7: Japanese Patent Laid-Open Publication No. 2012-006991

Patent Document 8: International Publication No. 2007/123039

Patent Document 9: Japanese Patent Laid-Open Publication No. 2010-523787

Non-patent literature

Non-Patent Document 1: Reworkable Photothermal Dual-Cure System (Chem. Letter, 2013, 42, 1056-1058)

As disclosed in Patent Document 1 to Patent Document 8, it is considered that in order to reduce the moisture permeability of the sealing layer, it is effective to add a hygroscopic filler or an organometallic compound to the sealing layer. However, when a hygroscopic filler or an organometallic compound is added, there is a case where the transparency of the cured product of the sealing material is impaired, or the viscosity of the sealing material is increased, and the wet diffusibility at the time of coating is lowered as a sealing material. The scope of application is limited. Further, depending on the use of various devices, there is a case where the sealing layer is required to be thinned. However, it is difficult to apply the conventional sealing material in a thin manner, and it is difficult to cope with such a demand.

In addition, it has been studied to increase the crosslinking density of the resin and to reduce the moisture permeability of the sealing layer. However, when the crosslinking density of the resin is increased, the shrinkage at the time of curing of the sealing material becomes large. As a result, there is a problem in that the substrate or the sealing substrate of the device including the sealing layer containing the cured material of the sealing material is likely to be strained. Further, there is also a problem that since the elastic modulus of the sealing layer is increased, the sealing layer cannot absorb stress strain from the outside, and the sealed object (for example, an organic EL element) cannot be sufficiently protected.

The present invention has been made in view of the above circumstances. That is, the present invention provides a sealing material capable of forming a sealing layer having a low moisture permeability and capable of coping with the formation of a thin sealing layer and having a moderately low elastic modulus.

That is, the first invention of the present invention relates to a sealing material shown below or a sheet-like sealing material obtained therefrom.

[1] A sealing material comprising: a polymerizable monomer (B) in each molecule There is at least one radical polymerizable functional group having a molecular weight of 50 or more and 1000 or less, which is liquid at 23 ° C; and an acid anhydride derivative (C) comprising at least one of a five-membered ring or a six-membered ring in each molecule. An acid anhydride group and a radical polymerizable functional group; a radical polymerization initiator (D) comprising at least one of a thermal radical polymerization initiator and a photoradical polymerization initiator.

[2] The sealing material according to [1], which further comprises: an olefin-based polymer (A) containing a polymerizable functional group, having at least one radical polymerizable functional group per molecule, and a number average molecular weight It is 5000 or more and 70,000 or less.

[3] The sealing material according to [1] or [2], wherein the viscosity measured by an E-type viscometer at 25 ° C, 1.0 rpm is 5 mPa. Above s, 20000mPa. s below.

[4] The sealing material according to any one of [1] to [3] wherein the polymerizable monomer (B) and the acid anhydride derivative (C) have the radically polymerizable The functional groups are each independently one or more functional groups selected from the group consisting of a (meth) acrylonitrile group, a vinyl group, an allyl group, and a vinyl ether group.

[5] The sealing material according to any one of [2] to [4] wherein the polymerizable functional group-containing olefin-based polymer (A) has the radical polymerizable functional group, It is at least one functional group selected from the group consisting of a (meth) acrylonitrile group, a vinyl group, an allyl group, and a vinyl ether group.

[6] The sealing material according to any one of [1] to [5] wherein the acid anhydride derivative (C) is a hexahydroortholine having at least one radical polymerizable functional group in each molecule. Phthalic anhydride derivative (C').

[7] A sheet-like sealing material which is densely described in any one of [1] to [6] Get the seal material.

The second invention of the present invention relates to a cured product of the sealing material shown below.

[8] A cured material of the sealing material according to any one of the above [1] to [6].

[9] The cured product of the sealing material according to any one of [2] to [6] wherein the elastic modulus is 0.1 MPa or more and 100 MPa or less.

[10] The cured product of the sealing material according to [8], wherein the parallel light transmittance at a wavelength of 400 nm is 90% or more.

[11] The cured product of the sealing material according to [9], wherein the parallel light transmittance at a wavelength of 400 nm is 90% or more.

[12] A sealing material comprising: an olefin-based polymer (A) having a polymerizable functional group, having at least one radical polymerizable functional group per molecule, and having a number average molecular weight of 5,000 or more and 70,000 or less; a hexahydrophthalic anhydride derivative (C') having at least one radical polymerizable functional group per molecule; a radical polymerization initiator (D) comprising a thermal radical polymerization initiator and light At least one of a radical polymerization initiator.

According to the sealing material of the present invention, a cured product having a low moisture permeability and a moderately low modulus of elasticity can be obtained. Further, since the viscosity of the sealing material can be lowered, the cured product (sealing layer) of the sealing material can be thinned.

2‧‧‧ glass substrate

4‧‧‧Extruding film

6‧‧‧ glass substrate

8‧‧·coating film

20, 20', 20" ‧ ‧ organic EL devices

22‧‧‧Substrate

24‧‧‧Organic EL components

26‧‧‧Seal substrate

28‧‧‧ face sealing layer

28-1‧‧‧ hardened layer

28-1'‧‧‧ Sealing material

28-2‧‧‧ Passivation layer

28-3‧‧‧Second resin hardened layer

28A‧‧‧First sealing layer

28B‧‧‧Second sealing layer

30‧‧‧Reflective electrode layer

32‧‧‧Organic EL layer

34‧‧‧Transparent counter electrode layer

36‧‧‧Block materials

L, L'‧‧‧ length

1A to 1C are schematic views showing a procedure for producing a sample for measuring the moisture permeability of a cured product by the Ca method.

2A is a schematic cross-sectional view showing one embodiment of an organic EL device, and FIG. 2B is a schematic cross-sectional view showing another embodiment of the organic EL device.

3A to 3C are schematic views showing an example of a manufacturing process of the organic EL device of Fig. 2A.

4A is a schematic cross-sectional view showing another embodiment of the organic EL device, and FIG. 4B is a plan view showing a state in which the sealing substrate of the organic EL device of FIG. 4A is removed.

1.About sealing material

The sealing material of the present invention is a composition for forming a sealing layer of various devices such as an organic EL device. The composition of the sealing material is appropriately selected depending on the purpose. For example, when a sealing layer having a small thickness is formed, a sealing material containing a polymerizable monomer (B), an acid anhydride derivative (C), and a radical polymerization initiator (D) is used. In this case, the sealing material may contain an olefin-based polymer (A) containing a polymerizable functional group as needed. On the other hand, when forming a sealing layer having a low modulus of elasticity, the olefin-based polymer (A), the acid anhydride derivative (C), and the radical polymerization initiator (D) containing a polymerizable functional group are included. Sealing material. At this time, a polymerizable monomer (B) may be contained as needed.

Previously, in order to improve the hygroscopicity of the sealing layer, it has been studied to add a hygroscopic filler or the like to the sealing material. However, when the sealing material contains a hygroscopic filler or the like, the transparency of the cured product of the sealing material is impaired, or the coating property of the sealing material is lowered, and it is difficult to sufficiently Cover the sealed object. Further, when the sealing material contains a filler or the like, there is also a problem that the viscosity of the sealing material becomes high, and it is difficult to thin the sealing layer. Further, it is also difficult to sufficiently reduce the moisture permeability of the cured product by merely adding the hygroscopic filler. On the other hand, in order to reduce the moisture permeability of the cured product of the sealing material, it has been studied to increase the crosslinking density of the resin, but in the method, there is a case where the hardening shrinkage of the sealing material becomes large, and the hardening of the sealing material The substrate of the deposited layer is strained. Further, there is a problem in that the cured product does not sufficiently absorb stress strain from the outside due to an increase in the elastic modulus of the cured product, and the sealed object or the like cannot be sufficiently protected.

On the other hand, in the cured product of the sealing material of the present invention, water is trapped by the acid anhydride group of the acid anhydride derivative (C) having a polymerizable functional group. Here, it is considered that even a normal acid anhydride such as hexahydrophthalic anhydride can capture the invaded water, and it is effective to add it to the sealing material. However, the usual acid anhydride does not undergo polymerization with other components in the sealing material. Therefore, it is easy to bleed out after the sealing material is hardened, and it is difficult to fully exhibit the moisture capturing performance. Further, if the compound bleeds out, there is a concern that the sealed object is contaminated.

On the other hand, the acid anhydride derivative (C) contained in the sealing material of the present invention has a functional group capable of radical polymerization, and an olefin-based polymer (A) or a polymerizable monomer (B) containing a polymerizable functional group. The polymerization reaction is carried out. Therefore, the structure (anhydride group) derived from the acid anhydride derivative (C) is uniformly present in the cured product. In other words, in the cured product of the sealing material of the present invention, the component (the acid anhydride derivative (C)) which captures moisture does not bleed out, and the moisture can be efficiently captured.

Further, in the sealing material of the present invention, by containing a polymerizable functional group The olefin-based polymer (A) and the acid anhydride derivative (C) are polymerized, and it is difficult to excessively increase the crosslinking density of the cured product. As a result, it is difficult for the sealing material to shrink during curing, and it is difficult to cause warpage or the like on the substrate or the like which is laminated with the cured material of the sealing material. Further, since the cured product has a moderately low modulus of elasticity and can absorb a load or the like from the outside, it is possible to sufficiently protect the object to be sealed from stress strain and the like from the outside.

In addition, when the sealing material of the present invention does not contain the polymerizable functional group-containing olefin-based polymer (A) or the content thereof is sufficiently small, the viscosity of the sealing material becomes low. As a result, the thickness of the obtained cured product (sealing layer) can be reduced by applying a sealing material by an inkjet method or the like.

Hereinafter, the polymerizable functional group-containing olefin-based polymer (A), the polymerizable monomer (B), the acid anhydride derivative (C), and the radical polymerization initiator (D) which may be contained in the sealing material of the present invention, And other ingredients to explain.

1-1. Olefin-based polymer containing a polymerizable functional group (A)

The olefin-based polymer (A) having a polymerizable functional group is an olefin-based polymer having at least one radical polymerizable functional group per molecule and having a number average molecular weight of 5,000 or more and 70,000 or less.

The number average molecular weight of the olefin-based polymer (A) having a polymerizable functional group is 5,000 or more and 70,000 or less, preferably 10,000 to 40,000. When the number average molecular weight of the olefin-based polymer (A) containing a polymerizable functional group is 70,000 or less, the fluidity of the sealing material is sufficiently improved, and various members are easily sealed by a sealing material. On the other hand, when the number average molecular weight of the olefin-based polymer (A) containing a polymerizable functional group is 5,000 or more, the elastic modulus of the cured product of the sealing material is liable to change. low.

Here, the number of the radically polymerizable functional groups contained in each molecule of the olefin-based polymer (A) containing a polymerizable functional group may be 1 or more, and the elastic modulus of the cured product of the sealing material may be desired. The number is set appropriately. When the number of radical polymerizable functional groups contained in the olefin-based polymer (A) containing a polymerizable functional group increases, the elastic modulus of the cured product of the sealing material is likely to be improved.

The radically polymerizable functional group contained in the olefin-based polymer (A) containing a polymerizable functional group may be a functional group having an ethylenically unsaturated bond. Specific examples thereof include a (meth) acrylonitrile group, a vinyl group, an allyl group, and a vinyl ether group. From the viewpoint of reactivity and the like, a (meth) acrylonitrile group or the like is preferable. When the polymerizable functional group-containing olefin-based polymer (A) contains a plurality of radically polymerizable functional groups, the plurality of radically polymerizable functional groups may be the same kind of functional groups or may be different a class of functional groups.

The olefin-based polymer (A) containing a polymerizable functional group may be a compound obtained by copolymerizing a "polyolefin-based polymer" and a "compound having a radical polymerizable functional group", or may be A compound having a radical polymerizable functional group, which is a compound obtained by modifying a "polyolefin-based polymer". The radically polymerizable functional group may be directly bonded to the polyolefin-based polymer or may be bonded to the polyolefin-based polymer via a divalent linking group. The type of the linking group to which the radically polymerizable functional group is bonded is not particularly limited, and examples thereof include a linear or branched alkyl group having 4 to 12 carbon atoms which may have a substituent; and a carbon which may have a substituent The number is 4 to 12, such as a cycloalkyl group. In addition, the linking group may include a portion of -COO-, -O-, and the like.

Further, examples of the substituent contained in the linking group include an alkyl group, a hydroxyl group, an alkoxy group, a carboxyl group, an alkoxy alkoxy group, an aralkyloxy group, an aryl group, an aryloxy group, and an aryloxyalkoxy group. A base, an alkylthio group, an alkylthioalkylthio group, an aralkylthio group, an arylthio group, an arylthioalkylthio group, a halogen atom or the like.

Examples of the "radical-polymerizable functional group bonded via a linking group" on the olefin-based polymer include a group represented by the following formula (Y2).

In the formula (Y2), R ₁₃ represents a hydrogen atom or a methyl group. In the above formula, R ₁₄ represents an alkylene group having 2 to 12 carbon atoms, preferably 2 to 6 carbon atoms. The alkylene group means any one of a linear alkyl group, a branched alkyl group, or a cycloalkyl group. Further, in the general formula (Y2), q represents a number of 1 or more and 23 or less. The olefin-based polymer (A) containing a polymerizable functional group may contain only one type of the group represented by the above formula (Y2) in one molecule, or may contain two or more types.

On the other hand, the polyolefin-based polymer as the main skeleton of the polymerizable functional group-containing olefin-based polymer (A) may be a polymer of at least one olefin selected from the group consisting of olefins having 2 to 20 carbon atoms. The polyolefin-based polymer may be an olefin The homopolymer may also be a random copolymer or a block copolymer of two or more kinds of olefins.

Examples of the olefin having a carbon number of 2 to 20 for obtaining a polyolefin-based polymer include ethylene, propylene, 1-butene, 1-pentene, 3-methyl-1-butene, and 1-hexene. , 4-methyl-1-pentene, 3-methyl-1-pentene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene a linear or branched α-olefin having 2 to 20 carbon atoms such as aene, 1-octadecene or 1-eicene; cyclopentene, cycloheptene, norbornene, 5-methyl Base-2-norbornene, tetracyclododecene, 2-methyl-1,4,5,8-dimethyl bridge-1,2,3,4,4a,5,8,8a-octahydrogen A cyclic olefin having 3 to 20 carbon atoms such as naphthalene.

Further, the olefin having 2 to 20 carbon atoms for obtaining the polyolefin-based polymer also includes vinylcyclohexane, a diene, a polyene or the like. Examples of the diene or polyene include a cyclic or chain compound having 4 to 20 carbon atoms and having two or more double bonds. Specifically includes: butadiene, isoprene, 4-methyl-1,3-pentadiene, 1,3-pentadiene, 1,4-pentadiene, 1,5-hexadiene, 1 , 4-hexadiene, 1,3-hexadiene, 1,3-octadiene, 1,4-octadiene, 1,5-octadiene, 1,6-octadiene, 1,7 -octadiene, ethylidene norbornene, vinyl norbornene, dicyclopentadiene, 7-methyl-1,6-octadiene, 4-ethylene-8-methyl-1, 7-decadiene, 5,9-dimethyl-1,4,8-nonanetriene, and the like.

Specific examples of the polyolefin-based polymer include polyethylene such as high-density polyethylene and medium-density polyethylene; polypropylene; poly-1-butene; polymethylbutene; ethylene/α-olefin copolymer; and ethylene-based elasticity An olefin-based elastomer such as a propylene elastomer or an isoprene rubber. The polyolefin-based polymer is preferably an olefin-based elastomer, and particularly preferably an isoprene rubber.

In addition, the reaction with the polyolefin-based polymer "has a radically polymerizable An example of the compound of the functional group to be combined includes a polymerizable monomer (B) or a derivative thereof described later. The "olefin having a radical polymerizable functional group" and a polyolefin-based polymer are reacted by a known method to obtain a polymerizable functional group-containing olefin-based polymer (A).

1-2. Polymerizable monomer (B)

The polymerizable monomer (B) is a compound having at least one radical polymerizable functional group per molecule, a molecular weight of 50 or more, 1,000 or less, and a liquid at 23 °C. When the sealing material contains the polymerizable monomer (B), the viscosity of the sealing material tends to be low, and the crosslinking density of the cured product of the sealing material is improved. Further, the polymerizable monomer (B) is not necessarily included in the acid anhydride derivative (C) described later.

The number of the radically polymerizable functional groups contained in each molecule of the polymerizable monomer (B) may be 1 or more, preferably 1 to 16, more preferably 1 to 4, and particularly preferably 1 to 3. . The radically polymerizable functional group contained in the polymerizable monomer (B) may be a vinyl group, a (meth) acrylonitrile group, an allyl group, a vinyl ether group or the like, and is preferably a (meth) acrylonitrile group. When the polymerizable monomer (B) contains a plurality of radically polymerizable functional groups, the plurality of radically polymerizable functional groups may be the same kind of functional groups, or may be different kinds of functional groups.

On the other hand, the polymerizable monomer (B) has a molecular weight of 50 to 1,000, preferably 50 to 500. When the molecular weight of the polymerizable monomer (B) is in the above range, it is easy to sufficiently adjust the viscosity of the sealing material.

Examples of the polymerizable monomer (B) include a mono(meth)acrylic monomer having one (meth)acrylinyl group in one molecule, and two in one molecule (A) A acrylonitrile-based di(meth)acrylic monomer.

The mono(meth)acrylic monomer having one (meth)acrylinyl group in one molecule is, for example, a monomer represented by the following formula (1B).

R ₇ in the formula (1B) represents a hydrogen atom or a methyl group. Further, R ₈ in the formula (1B) represents a hydrogen atom or a hydrocarbon group having 4 to 18 carbon atoms. The hydrocarbon group having 4 to 18 carbon atoms represents a linear alkyl group, a branched alkyl group, or an alicyclic hydrocarbon group.

Specific examples of the mono(meth)acrylic monomer represented by the above formula (1B) include: (meth)acrylic acid, n-butyl (meth)acrylate, isobutyl (meth)acrylate, (a) 2-ethylhexyl acrylate, lauryl (meth)acrylate, isostearyl (meth)acrylate, isoamyl (meth)acrylate, isodecyl (meth)acrylate, (methyl) Isooctyl acrylate, isomyristyl (meth)acrylate, tridecyl (meth)acrylate, cyclohexyl (meth)acrylate, dicyclopentenyloxyethyl acrylate, and the like. The sealing material of the present invention may contain only one type of the mono(meth)acrylic monomer, and may also contain two or more types.

Di(meth)acrylic acid having two (meth)acrylonitrile groups in one molecule The monomer may be a monomer represented by the following formula (2B).

R ₉ and R ₁₀ in the formula (2B) each independently represent a hydrogen atom or a methyl group. Further, in the formula (2B), R ₁₁ represents a hydrocarbon group having 4 to 12 carbon atoms. The hydrocarbon group having 4 to 12 carbon atoms represents a linear alkyl group, a branched alkyl group, or a cycloalkyl group.

Specific examples of the di(meth)acrylic monomer represented by the above formula (2B) include: 1,3-butanediol di(meth)acrylate, 1,4-butanediol di(methyl) ) acrylate, 1,6-hexanediol di(meth)acrylate, neopentyl glycol di(meth)acrylate, 1,9-nonanediol di(meth)acrylate, and the like. The sealing material may contain only one kind of the above-mentioned di(meth)acrylic monomer, and may contain two or more types.

When a mono(meth)acrylic monomer and a di(meth)acrylic monomer are contained in the sealing material, the content ratio of the monomer is arbitrary, but the content ratio of the di(meth)acrylic monomer is When the number is increased, the adhesion reliability in a high-temperature and high-humidity environment is improved.

Further, examples of the polymerizable monomer (B) include a monomer having one or more vinyl groups in one molecule, a monomer having one or more allyl groups in one molecule, and one or more vinyl ethers in one molecule. A monomer of a group, a vinyl ether compound having a (meth) acrylonitrile group in one molecule.

Examples of the monomer having a vinyl group in one molecule include: styrene, p-hydroxystyrene, p-chlorostyrene, p-bromostyrene, p-methylstyrene, p-methoxystyrene, and p-butadiene An aromatic vinyl compound such as oxystyrene, p-tert-butoxycarbonyloxystyrene, 1-vinylnaphthalene or 2-vinylnaphthalene; 1-heptene, 3,3-dimethyl-1- Pentene, 4,4-dimethyl-1-pentene, 2,4-diphenyl-4-methyl-1-pentene, 3-methyl-1-hexene, 4-methyl-1 -hexene, 5-methyl-1-hexene, 1-octene, 2,2-dimethyl-1-hexene, 3,4-dimethyl-1-hexene, 4,4-di Methyl-1-hexene, 1-decene, 3,5,5-trimethyl-1-hexene, 1-decene, 1-undecene, 1-dodecene, 1-ten Tricarbene, 1-tetradecene, 1-pentadecene, 1-hexadecene, 1-heptadecene, 1-octadecene, 1-nonadecene, 1-twenty An aliphatic vinyl compound such as carbene or 1-docosene; vinyl acetate, vinyl monochloroacetate, vinyl benzoate, vinyl pivalate, vinyl butyrate, vinyl laurate, and dimethoate Vinyl acetate, vinyl methacrylate, crotonic acid A vinyl carboxylate compound such as vinyl ester or vinyl 2-ethylhexanoate; or a vinyl compound containing a nitrogen atom such as N-vinylcarbazole or N-vinylpyrrolidone.

Examples of the monomer having one or more allyl groups in one molecule include: diallyl phthalate, diallyl isophthalate, diallyl terephthalate, trimethylolpropane II Allyl ether, triallyl cyanurate, trimethylallyl isocyanurate, triallyl cyanurate, and the like.

Examples of the monomer having one or more vinyl ether groups in one molecule include ethyl vinyl ether, isobutyl vinyl ether, butanediol divinyl ether, cyclohexyl vinyl ether, hydroxybutyl vinyl ether, hydroxyethyl ethylene. Ether, cyclohexane dimethanol divinyl ether, Cyclohexane dimethanol monovinyl ether, diethylene glycol divinyl ether, triethylene glycol divinyl ether, triethylene glycol monovinyl ether, and the like.

Examples of the vinyl ether compound having a (meth)acryl fluorenyl group in one molecule include 2-(2-vinyloxyethoxy)ethyl acrylate or 2-(2-ethyleneoxyethoxy) methacrylate Ethyl ester and the like.

1-3. Anhydride derivative (C)

The acid anhydride derivative (C) is a compound having at least one radical polymerizable functional group in each molecule and constituting an acid anhydride group of a five-membered ring or a six-membered ring, and may be, for example, a radically polymerizable bond on various acid anhydrides. A functional group of compounds. The number of the radically polymerizable functional groups contained in each molecule of the acid anhydride derivative (C) may be 1 or more, preferably 1. When the acid anhydride derivative (C) contains a radical polymerizable functional group, the polymerizable monomer (B) or the polymerizable functional group-containing olefin polymer (A) at the time of curing of the sealing material The acid anhydride derivative (C) is polymerized to inhibit the bleeding of the acid anhydride derivative (C).

The radically polymerizable functional group contained in the acid anhydride derivative (C) may be a functional group having an ethylenically unsaturated bond. Specific examples thereof include a (meth) acrylonitrile group, a vinyl group, an allyl group, and a vinyl ether group. From the viewpoint of reactivity and the like, a (meth) acrylonitrile group or the like is preferable. The radically polymerizable functional group may be directly bonded to the main skeleton including the acid anhydride group, or may be bonded via a linking group. The linking group may be the same as the linking group of the polymerizable functional group-containing olefin polymer (A) in which the radical polymerizable functional group is bonded to the polyolefin polymer. When the acid anhydride derivative (C) comprises a plurality of radically polymerizable functional groups, the plurality of radically polymerizable functional groups may be of the same kind The functional groups may also be different kinds of functional groups.

The acid anhydride derivative (C) can be, for example, a compound represented by the following formula (1C).

In the above formula (1C), X represents an organic group having 2 to 14 carbon atoms (wherein the number of carbon atoms contained in the acid anhydride groups is 2 or 3), and R ₁ represents a radically polymerizable functional group, Y Represents a single bond or a linker. Further, n represents a number of 1 or more and 12 or less.

X in the above formula (1C) may be, for example, an aliphatic group; a monocyclic aliphatic group; a condensed polycyclic aliphatic group; a monocyclic aromatic group; a condensed polycyclic aromatic group; A non-condensed polycyclic aliphatic group in which an aliphatic group is bonded to each other directly or by a crosslinker; a non-condensed polycyclic aromatic group in which an aromatic group is bonded to each other directly or by a crosslinker.

The X is more specifically a structure derived from various acid anhydrides, and may be, for example, a group derived from an aromatic dicarboxylic anhydride or an alicyclic dicarboxylic anhydride. Examples of the aromatic dicarboxylic acid anhydride include phthalic anhydride, naphthalic anhydride, phthalic anhydride, and the like. On the other hand, examples of the alicyclic dicarboxylic anhydride include succinic anhydride, maleic anhydride, and tetrahydrogen Phthalic anhydride, hexahydrophthalic anhydride, 5-norbornene-2,3-dicarboxylic anhydride, (1α, 4α)-norbornane-2α, 3α-dicarboxylic anhydride, and the like.

Further, X may have a substituent. The substituent may be an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, a phenoxy group or a halogen.

On the other hand, R ₁ in the above formula (1C) may specifically be a (meth) acrylonitrile group, a vinyl group, an allyl group or a vinyl ether group.

Further, when Y in the above formula (1C) is a linking group, Y may be an alkylene group selected from a carbon number of 1 to 10, and a carbon number of 2 to 10 containing one to three unsaturated groups. An alkenyl group or a divalent linking group that stretches a phenyl group. A portion of the hydrogen of the linking group may be replaced by a halogen.

The acid anhydride derivative represented by the above formula (1C) is preferably a hexahydrophthalic anhydride derivative (C') or a phthalic anhydride derivative (C"), particularly preferably a hexahydrophthalic acid derivative. Formaldehyde anhydride derivative (C').

Specific examples of the hexahydrophthalic anhydride derivative include compounds represented by the following formula (2C). The molecular weight of the compound is preferably from 296 to 5,000.

In the above formula (2C), n represents a number of 1 or more and 4 or less. Further, in the above formula (2C), R ₁₁ each independently represents a group containing one or more radically polymerizable functional groups. R _{11 is} preferably a group represented by the following formula (X1), a group containing a vinyl group, a group containing an allyl group, or a group containing a vinyl ether group.

In the above formula (X1), R ₃ is a hydrogen atom or a methyl group. In the above formula, R ₄ represents a linear alkyl group, a branched alkyl group, or a cycloalkyl group having a carbon number of 2 to 12, preferably 2 to 6 carbon atoms. Further, in the general formula (X1), p represents a number of 1 or more and 23 or less.

Further, examples of the "vinyl group-containing group" corresponding to R ₁₁ in the above formula (2C) include: 1,3-dimethoxy octahydroisobenzofuran-5-carboxylic acid 3-butene -1-yl ester group, 1,3-dihydroxy octahydroisobenzofuran-5-carboxylic acid 5-hexyl-1-yl ester, 1,3-di- oxy octahydroisobenzofuran- 5-carboxylic acid 7-octene-1-yl ester group.

Further, in the above formula (2C), examples of the "allyl-containing group" corresponding to R ₁₁ include: 1,3-di- oxy octahydroisobenzofuran-5-carboxylic acid allylic acid Ester group, 1,3-dihydroxy octahydroisobenzofuran-5-carboxylic acid 2-(allyloxy)ethyl ester group.

In the above formula (2C), "corresponding to R11" Examples of the group include: 1,3-dimethoxy octahydroisobenzofuran-5-carboxylic acid 2-(vinyloxy)ethyl ester, 1,3-di- oxy octahydroisobenzofuran -5-carboxylic acid 2-(2-(vinyloxy)ethoxy)ethyl ester, 1,3-dimethoxy octahydroisobenzofuran-5-carboxylic acid 4-(vinyloxy)butyl ester .

The compound represented by the above formula (2C) may have a substituent. The substituent is not particularly limited as long as it does not impair the effects of the present invention, and may be, for example, a linear or branched alkyl group having 1 to 5 carbon atoms.

A particularly preferred example of the acid anhydride derivative (C) is a compound represented by the following formula (3C).

In the above formula (3C), R ₅ represents a hydrogen atom or a methyl group.

1-4. Radical polymerization initiator (D)

The radical polymerization initiator (D) is an olefin-based polymer (A), an acid anhydride derivative (C), or a polymerizable monomer (B) containing a polymerizable functional group by heating or light irradiation. a compound that undergoes radical polymerization. The radical polymerization initiator (D) may be a photoradical polymerization initiator or a thermal radical polymerization initiator. Sealing material The type of the radical polymerization initiator (D) to be contained is appropriately selected depending on the method of curing the sealing material, and the sealing material may contain only one of the radical polymerization initiators (D), or may contain two By.

The photoradical polymerization initiator is not particularly limited and may be a known photoradical polymerization initiator. Examples of the photoradical polymerization initiator include an alkylphenone compound, a mercaptophosphine oxide compound, a titanocene compound, an oxime ester compound, a benzoin compound, an acetophenone compound, and a benzophenone. Compound, thioxanthone compound, α-oxime ester compound, benzoic acid ester compound, benzoin compound, azo compound, diphenyl sulfide compound, organic pigment compound, iron a phthalocyanine compound, a benzoin ether compound, an anthraquinone compound, or the like. The sealing material may contain only one kind of the photoradical polymerization initiator, and may contain two or more kinds.

The photoradical polymerization initiator is particularly preferably an alkylphenone compound or a mercaptophosphine oxide compound from the viewpoint of reactivity and the like.

On the other hand, the thermal radical polymerization initiator is not particularly limited and may be a known thermal radical polymerization initiator. The thermal radical polymerization initiator may be, for example, a known organic peroxide. Examples of the thermal radical polymerization initiator include: 2,4-dichlorobenzidine peroxide, tert-butyl peroxypivalate, 3,5,5-trimethylhexyl peroxide, peroxyoctane Bismuth, ruthenium peroxide, ruthenium peroxide, peroxy succinic acid, acetonitrile peroxide, peroxidation (t-butyl 2-ethylhexanoate), peroxidation (third ester of 2-ethylhexanoate) ), benzammonium peroxide, benzamidine peroxide, tert-butyl peroxymaleate, tributyl butyl laurate, peroxy-3,5,5-trimethylhexanoic acid Third butyl ester, Cyclohexanone peroxide, tert-butyl isopropyl carbonate, 2,5-dimethyl-2,5-bis(benzylidene peroxy)hexane, 2,2-double (third Butylperoxy)octane, tert-butyl peroxyacetate, 2,2-bis(t-butylperoxy)butane, tert-butyl peroxybenzoate, 4,4-di( N-butylperoxy)n-butyl valerate, di-t-butyl peroxy isophthalate, dicumyl peroxide, methyl ethyl ketone peroxide, and the like. The sealing material may contain only one thermal radical polymerization initiator, and may also contain two or more types.

Further, the sealing material may contain a radical chain transfer agent together with the radical polymerization initiator. When the radical chain transfer agent is contained, the hardenability of the sealing material is further improved. Examples of the radical chain transfer agent include α-methylstyrene dimers, mercapto-containing mercaptans, diphenyl disulfides and the like, and terminal unsaturated methacrylate n-polymers. Porphyrin cobalt complexes and the like. The sealing material may contain only one type of radical chain transfer agent, and may contain two or more types.

The content of the radical chain transfer agent is preferably from 0.1 part by mass to 10 parts by mass, more preferably from 0.5 part by mass to 5 parts by mass, per 100 parts by mass of the total of the compound having a radical polymerizable functional group.

1-5. Other ingredients

Other resins may be contained in the sealing material insofar as the effects of the present invention are not greatly impaired. The other resin may be, for example, a thermosetting resin or the like. Examples of the thermosetting resin include an epoxy resin, a phenol resin, a diallyl phthalate resin, a urea resin, a polyester resin, and the like. The sealing material may contain only one type of thermosetting resin, and may contain two or more types.

A filler may be included in the sealing material. Example of a filler contained in a sealing material The invention includes glass beads, styrene polymer particles, methacrylate polymer particles, ethylene polymer particles, and propylene polymer particles. The sealing material may contain only one type of filler, and may contain two or more types.

A modifier or stabilizer may be included in the sealant. Specific examples of the modifier include an anti-aging agent, a leveling agent, a wettability improver, a surfactant, a plasticizer, and the like. These modifiers may be used alone or in combination of two or more. On the other hand, specific examples of the stabilizer include an ultraviolet absorber, a preservative, an antibacterial agent, and the like. The modifier or the stabilizer may be contained in the sealing material alone or in combination of two or more.

An antioxidant may be included in the sealing material. The antioxidant is a person who inactivates a radical generated by plasma irradiation or sunlight irradiation (Hindered Amine Light Stabilizer (HALS)) or decomposes a peroxide. The antioxidant has a function of preventing discoloration of the cured product of the sealing material. The antioxidant may be a hindered amine, a phenolic antioxidant, a phosphorus antioxidant, or the like.

Examples of hindered amines include: bis(2,2,6,6-tetramethylpiperidin-4-yl)sebacate, 2,4-dichloro-6-th-octylamino-s-triazine Polycondensation product with 4,4'-hexamethylenebis(Amino-2,2,6,6-tetramethylpiperidine), bis[1-(2-hydroxy-2-methylpropoxy) -2,2,6,6-tetramethylpiperidin-4-yl] sebacate.

Examples of the phenolic antioxidant include monophenols such as 2,6-di-t-butyl-p-cresol and 2,2'-methylenebis(4-methyl-6-tert-butylphenol). A polymer phenol such as a bisphenol or a 1,1,3-tris(2-methyl-4-hydroxy-5-t-butylphenyl)butane.

Phosphorus-based antioxidants are preferably used: antioxidants selected from phosphites And an anti-coloring agent selected from the group consisting of oxaphosphorus phenanthrene oxides.

Particularly, in terms of imparting resistance to ultraviolet rays, Tinuvin 123 (bis(1-octyloxy-2,2,6,6-tetramethyl-4-piperidyl)fluorene is preferred. Acid ester), Tinuvin 765 (bis(1,2,2,6,6-pentamethyl-4-piperidyl) sebacate and 1,2,2,6,6-five a mixture of methyl 4-piperidinyl sebacate), Hostavin PR25 (dimethyl 4-methoxybenzylmalonate), Tinuvin 312 or ho Hostavin vsu (ethane-amine N-(2-ethoxyphenyl)-N'-(2-ethylphenyl)), CHIMASSORB 119 FL (N, N '-Bis(3-Aminopropyl)ethylenediamine-2,4-bis[N-butyl-N-(1,2,2,6,6-pentamethyl-4-piperidinyl)amine a -6-chloro-1,3,5-triazine condensate.

The sealing material of the present invention may contain a solvent as needed. The solvent has a function of uniformly dispersing or dissolving each component. Examples of the solvent include aromatic solvents such as toluene and xylene; ketone solvents such as acetone, methyl ethyl ketone and methyl isobutyl ketone; ether, dibutyl ether, tetrahydrofuran, dioxane, and ethylene glycol monoalkane. An ether such as ether; an aprotic polar solvent such as N-methylpyrrolidone; an ester such as ethyl acetate or butyl acetate.

1-6. Composition of sealing material

As described above, the composition of the sealing material of the present invention is appropriately selected depending on the use of the sealing material. For example, when the sealing material is ejected from the ink jet head, it is preferred that the sealing material has a low viscosity. Therefore, it is preferable to have a composition containing at least the polymerizable monomer (B), the acid anhydride derivative (C), and the radical polymerization initiator (D).

In this case, the polymerizable monomer (B) is preferably contained in an amount of 60% by mass to 96% by mass, and more preferably 70% by mass to 89% by mass based on the total amount of the sealing material. If aggregated When the amount of the monomer (B) is 60% by mass or more, the cured product of the sealing material has sufficient strength. On the other hand, when the amount of the polymerizable monomer (B) is 90% by mass or less, the acid anhydride derivative (C) is relatively sufficiently contained, and the moisture permeability of the cured product of the sealing material is lowered.

Further, the acid anhydride derivative (C) is preferably contained in an amount of from 3% by mass to 39% by mass, more preferably from 10% by mass to 29% by mass, based on the total amount of the sealing material. When the amount of the acid anhydride derivative is 3% by mass or more, the moisture permeability of the cured product of the sealing material is sufficiently lowered.

Furthermore, it is preferable to contain 1 part by mass to 25 parts by mass of the radical polymerization initiator (D), more preferably 100 parts by mass based on the total mass of the polymerizable monomer (B) and the acid anhydride derivative (C). 1 part by mass to 20 parts by mass. When the amount of the radical polymerization initiator (D) is in the above range, the polymerizable monomer (D) or the acid anhydride derivative (C) is sufficiently hardened, and the elastic modulus of the cured product of the sealing material easily converges on the desired In the range.

In addition, the sealing material may contain the polymerizable functional group-containing olefin-based polymer (A) in an amount of 1% by mass to 10% by mass based on the total amount of the sealing material.

On the other hand, when the viscosity of the sealing material can be high or the elastic modulus of the cured product of the sealing material is lowered, the olefin-based polymer (A) containing an polymerizable functional group or an acid anhydride can be used. The composition of the substance (C) and the radical polymerization initiator (D). At this time, a polymerizable monomer (B) may be contained as needed.

At this time, it is preferable to contain 30 masses with respect to the total amount (mass) of the sealing material. The amount of the polymerizable functional group-containing olefin-based polymer (A) in an amount of from 90% by mass to 90% by mass is more preferably from 30% by mass to 60% by mass. When the amount of the polymerizable functional group-containing olefin polymer (A) is 30% by mass or more, the elastic modulus of the cured product of the sealing material easily converges within a desired range. On the other hand, when the amount of the olefin-based polymer (A) containing a polymerizable functional group is 90% by mass or less, the acid anhydride derivative (C) is relatively sufficiently contained, and the moisture permeability of the cured product of the sealing material is lowered.

In addition, the amount of the polymerizable monomer (B) is preferably 65 with respect to the total mass of the polymerizable functional group-containing olefin polymer (A), the acid anhydride derivative (C), and the polymerizable monomer (B). The mass% or less is more preferably 5% by mass to 50% by mass. When the amount of the polymerizable monomer (B) is in the above range, the elastic modulus of the sealing material can be relatively lowered.

Further, the acid anhydride derivative (C) is preferably contained in an amount of from 3% by mass to 40% by mass based on the total mass (mass) of the sealing material. When the amount of the acid anhydride derivative (C) is 3% by mass or more, the moisture permeability of the cured product of the sealing material is sufficiently lowered. On the other hand, when the amount of the acid anhydride derivative (C) in the sealing material is 40% by mass or less, the olefin-based polymer (A) containing a polymerizable functional group is relatively sufficiently contained, and the elastic modulus of the sealing material is changed. low.

In addition, the total amount of the compound having a radical polymerizable functional group, that is, the total amount of the polymerizable functional group-containing olefin polymer (A), the acid anhydride derivative (C), and the polymerizable monomer (B) The radical polymerization initiator (D) is preferably 2 parts by mass to 15 parts by mass, more preferably 5 parts by mass to 10 parts by mass, per 100 parts by mass.

1-7. Physical properties of sealing materials

The sealing material of the present invention is measured by an E-type viscometer at 25 ° C and 1.0 rpm. Viscosity, preferably 5mPa. s~20000mPa. s. When the viscosity of the sealing material is within the above range, the coating property (for example, screen printing property or inkjet printing property) of the sealing material is improved, and coating is facilitated. The viscosity of the sealing material is measured by, for example, an E-type viscometer of RC-500 manufactured by Toki Sangyo Co., Ltd., or the like.

When the sealing material is applied by screen printing or dispenser coating, the viscosity of the sealing material of the present invention measured by an E-type viscometer at 25 ° C and 1.0 rpm is preferably 10 mPa. s~20000mPa. s, more preferably 10mPa. s~5000mPa. s.

On the other hand, when the sealing material is applied by inkjet printing, the viscosity of the sealing material of the present invention measured by an E-type viscometer at 25 ° C and 1.0 rpm is preferably 5 mPa. s~1000mPa. s, more preferably 5mPa. s~100mPa. s.

Further, the water content of the sealing material is preferably 0.5% by mass or less, more preferably 0.1% by mass or less, and still more preferably 0.06% by mass or less. Since the circuit in which the organic EL element is disposed is easily deteriorated by moisture, it is preferable to reduce the moisture content of the sealing material as much as possible.

The moisture content of the sealing material can be determined by measuring a sample of about 0.1 g of the sample and heating it to 150 ° C using a Karl Fisher moisture meter to measure the amount of water produced at this time (solid gas). Method).

The sealing material of the present invention is preferably used as a sealing material for forming a sealing layer for an optical semiconductor. The optical semiconductor is, for example, an element that converts electricity into light and emits light. The optical semiconductor specifically includes an inorganic light emitting diode (LED) element, an organic EL element, or the like, and is preferably an organic EL element. Since the photo-semiconductor is easily deteriorated by moisture or the like, it is necessary to seal the surface.

Further, according to the sealing material of the present invention, it is possible to protect a component (for example, a dye or the like) which is easily deteriorated by moisture or the like. The cured product of the sealing material of the present invention has a low moisture permeability. Therefore, when a component which is easily deteriorated by moisture or the like is added to the sealing material, the component is less likely to come into contact with moisture, and deterioration thereof can be suppressed.

The sealing material of the present invention covers the sealed object in a liquid state and is cured to form a sealing layer. When the object to be sealed is coated in a liquid state, for example, it is applied to an optical semiconductor such as an organic EL device by screen printing, dispenser coating, inkjet coating, or the like, and the coating layer is cured to be organic. The optical semiconductor such as an EL element may be surface-sealed. Further, after the sealing material of the present invention is formed into a film shape, the sealed object can be sealed by the film. After the film is sealed, the film-like sealing material is laminated on an optical semiconductor such as an organic EL element and cured, whereby an optical semiconductor such as an organic EL element is surface-sealed.

The method of curing the sealing material is appropriately selected depending on the type of the radical polymerization initiator, and the like. When it is a thermosetting type sealing material, the sealing material is hardened by heating. The heating temperature may be set to a temperature higher than 23 ° C, and is appropriately set in consideration of the heat-resistant temperature, efficiency, and the like of the sealed object.

On the other hand, in the case of a photocurable sealing material, the sealing material is cured by light irradiation. The wavelength of the light to be irradiated is appropriately selected depending on the type of the photoradical polymerization initiator, and the like, and may be, for example, ultraviolet light or visible light. The integrated light amount of the irradiated light is usually about 100 mJ/cm ² to 10000 mJ/cm ² . Heating can be further performed after light irradiation.

1-8. Method for manufacturing sealing material

The sealing material of the present invention can be produced by any method as long as the effects of the present invention are not impaired. For example, it is produced by the following steps: 1) a step of preparing an olefin-based polymer (A) containing a polymerizable functional group, a polymerizable monomer (B), an acid anhydride derivative (C), and a polymerization initiator (D); And 2) a step of mixing the components at 30 ° C or lower in an inert gas atmosphere. The mixing includes a method of dispersing the components by a ball mill, a method of charging in a flask, or a method of kneading by three rolls.

When the sealing material of the present invention is formed into a film shape, for example, a liquid sealing material may be applied onto a release substrate, and the coating film may be dried and peeled off. The coating of the sealing material may be carried out by a method such as screen printing or dispenser coating.

1-9. About the hardened material of the sealing material

The moisture permeability of the cured product of the sealing material of the present invention is preferably as low as possible. That is, the Ca reaction start time at 60 ° C and 90% RH measured by the following method is preferably 24 hours or longer. The longer the Ca reaction start time is, the lower the moisture permeability of the cured product is.

The moisture permeability (Ca reaction start time) of the cured product by the Ca method can be measured by the following procedure. FIG. 1 is a schematic view showing a procedure for producing a sample for measuring moisture permeability of a cured product by a Ca method.

1) Production of samples

As shown in FIG. 1A, a glass substrate 2 (size: 25 mm × 25 mm, thickness: 0.7 mm) which was immersed in acetone and subjected to ultrasonic cleaning for 10 minutes was prepared. On the glass substrate 2, a vapor deposition film 4 of metal calcium having a thickness of 170 nm was formed under the following conditions using a vapor deposition machine (manufactured by ALS Technology). A mask for vapor deposition is used, from the end of the vapor-deposited film 4 of the metal calcium to the end of the glass substrate 2 The length L so far is adjusted to be 4 mm.

(evaporation conditions)

Vacuum degree during vapor deposition: 3.0 × 10 ^-5 Pa

Film forming speed: 1.2 Å / sec

Metal Calcium Raw Material: High Purity Chemical Manufacturing, Granules

The obtained glass substrate with the metal calcium-deposited film was moved to a glove box of an N ₂ atmosphere without being exposed to the air. Then, as shown in FIG. 1B, the sealing material of the present invention was dropped on the separately prepared acetone-cleaned glass substrate 6 (25 mm × 55 mm, thickness: 2 mm) so that the thickness after hardening became 100 μm. The coating film 8 is formed by drying.

Then, as shown in FIG. 1C, a glass substrate having a coating film with a sealing material and a glass substrate with a vapor deposition film attached thereto are bonded together to form a laminate, which is fixed by a jig. The thickness of the obtained laminate can be sandwiched between Teflon (registered trademark) sheets having a thickness of 100 μm between a glass substrate having a coating film with a sealing material and a glass substrate with a vapor deposited film of metal calcium. Adjustment is performed as a spacer or the like. The length L' from the end of the vapor deposited film 4 of the metal calcium to the end of the coating film 8 is also set to 4 mm.

Then, in the case of a thermosetting sealing material, the laminate was heated at 100 ° C for 30 minutes in an oven to cure the sealing material as a sample. In the case of a photocurable sealing material, the laminate was irradiated with ultraviolet rays of 3,000 mJ by a mercury lamp, and then heated at 80 ° C for 30 minutes to cure the sealing material as a sample.

2) Determination of the start time of Ca reaction

The resulting sample was stored at 60 ° C and 90% RH in a constant temperature and humidity chamber. Then, the time (Ca reaction start time) from the end of the vapor deposition film of metal calcium from the metallic luster was measured. That is, when metal calcium (metal luster) reacts with water, it becomes transparent calcium hydroxide Ca(OH) ₂ . The longer the Ca reaction start time, the more difficult it is to cause the reaction of metallic calcium with water, and the lower the moisture permeability.

As described later, in the organic EL device, moisture or oxygen in the atmosphere easily enters from the gap between the substrate and the sealing substrate. Therefore, the moisture permeability of the sealing layer in the organic EL device is close to the actual device configuration as compared with the cup method, and can be measured by the evaluation unit, so that the evaluation can be performed with high precision. The moisture permeability measured by the normal cup method is mainly evaluated for the moisture permeability from the direction in which the main surface of the organic EL device intrudes (the direction from the self-sealing substrate 26 to the substrate 22 in FIG. 2A described later), whereas the Ca method is used. The measured moisture permeability is mainly the moisture permeability from the direction in which the side surface of the organic EL device invades (the direction from the gap between the self-sealing substrate 26 and the substrate 22 in FIG. 2A to the side surface of the organic EL element to be described later). In this way, the Ca method can evaluate the moisture intrusion in the atmosphere or the direction in which oxygen enters, that is, the moisture permeability in the direction in which the side surface of the organic EL device intrudes, so that the moisture permeability of the sealing layer of the organic EL device can be accurately evaluated.

Here, the elastic modulus of the cured product of the sealing material of the present invention is appropriately selected depending on the use or composition of the sealing material. For example, when the sealing material contains the polymerizable functional group-containing olefin polymer (A), it is preferably 0.1 MPa or more and 100 MPa or less, and more preferably 0.1 MPa to 20 MPa. When the elastic modulus of the cured product of the sealing material is 100 MPa or less, the sealed object is protected from external stress strain and the like by the layer containing the cured product of the sealing material. The elastic modulus of the cured product of the sealing material was determined in the following manner. In the tensile testing machine, the distance between the chucks is 30mm. The sample was measured for strain at an initial load of 10 N and a tensile speed of 30 mm/min. Then, the elastic modulus is calculated from the slope of the straight line portion of the stress-strain curve in which the stress is taken on the vertical axis and the strain is taken on the horizontal axis. On the other hand, when the sealing material does not contain the polymerizable functional group-containing olefin polymer (A), the elastic modulus can be set to 10 MPa to 10 GPa.

The transmittance of the parallel light having a wavelength of 400 nm of the cured product of the sealing material of the present invention is preferably 90% or more, more preferably 95% or more. When the transmittance of the parallel light of the cured product is 90% or more, the sealing material can be applied to various sealing members for optical semiconductors. The transmittance of the parallel rays is the transmittance of the parallel rays of the cured product of the sealing material of 100 μm, and is measured by an ultraviolet-visible spectrophotometer or the like.

2. Organic EL device

In general, an organic EL device includes an organic EL element disposed on a substrate, a sealing substrate paired with the substrate, and a sealing layer disposed between the substrate and the sealing substrate and covering (surface sealing) the organic EL element. A part or all of the sealing layer may be set as a cured product of the sealing material. Further, since the cured product of the sealing material of the present invention has a low moisture permeability as described above, when the organic EL element is not completely covered, or when other members are interposed between the cured product of the sealing material of the present invention and the organic EL element. It also protects the organic EL element from moisture. Further, even in the organic EL device having the structure in which the sealing substrate is not provided, the cured product of the sealing material of the present invention can be used as a sealing material for protecting the organic EL element from moisture. When the cured product of the sealing material of the present invention is used as a sealing material for protecting the organic EL element from moisture, the structure of the organic EL device is not limited. The organic EL device may be an organic EL display panel or an organic EL illumination or the like.

2A is a schematic cross-sectional view showing one embodiment of an organic EL device. In this embodiment, the entire surface sealing layer is an example of a cured product of the sealing material. As shown in FIG. 2A, the organic EL device 20 sequentially laminates the substrate 22, the organic EL element 24, and the sealing substrate 26. A face seal layer 28 is disposed between the substrate 22 and the sealing substrate 26, and the face seal layer 28 covers the periphery of the organic EL element 24. Thus, the surface sealing layer 28 performs surface sealing of the organic EL element 24.

The substrate 22 and the sealing substrate 26 are usually a glass substrate or a resin film, and at least one of the substrate 22 and the sealing substrate 26 is a transparent glass substrate or a transparent resin film. Examples of such a transparent resin film include an aromatic polyester resin such as polyethylene terephthalate or the like.

When the organic EL element 24 is of the top emission type, the organic EL element 24 includes a reflective pixel electrode layer 30 (including aluminum or silver, etc.), an organic EL layer 32, and a transparent counter electrode layer 34 (including ITO) from the substrate 22 side. (Indium Tin Oxide: Indium Tin Oxide) or IZO (Indium Zinc Oxide). The reflective pixel electrode layer 30, the organic EL layer 32, and the transparent counter electrode layer 34 can be formed by vacuum deposition, sputtering, or the like.

The face seal layer 28 can be a cured product containing the seal member of the present invention. The parallel light transmittance of the surface seal layer 28 containing the cured product of the sealing material of the present invention is preferably 90% or more as described above. The reason is that if the parallel light transmittance is too low, the light extraction efficiency from the element or the light absorption efficiency on the element is liable to lower. The upper limit of the light transmittance of the surface seal layer 28 can be set, for example, to about 99%.

As described above, since the sealing material of the present invention has a viscosity which is adjusted to a relatively low range, the coating property is good, and the surface sealing layer 28 having a uniform film thickness can be formed. Further, the cured product of the sealing material of the present invention is sufficiently lowered in particular by the moisture permeability of the Ca method. low. Therefore, the surface seal layer 28 containing the cured product of the sealing material of the present invention can capture moisture or oxygen in the atmosphere which enters the gap between the substrate 22 and the sealing substrate 26, that is, the side surface of the organic EL element, and can suppress The moisture, oxygen, or the like is in contact with the organic EL element 24.

In addition, the permeation of moisture intrinsic from the main surface side of the organic EL device 20 to the inner direction (the direction from the sealing substrate 26 to the substrate 22 in FIG. 2A) can be made low by the substrate 22 or the sealing substrate 26 The material is suppressed.

Other aspects of the organic EL device include a configuration in which: 1) an organic EL element disposed on a substrate; 2) a resin cured layer that is in contact with the organic EL element and covers (surface-seales) the organic EL element; 3) a passivation layer which is in contact with the cured resin layer to cover the cured layer of the resin; 4) a sealing substrate which covers the passivation layer (refer to FIG. 2B). The cured resin layer may be a cured product of the sealing material.

2B is a schematic cross-sectional view showing another embodiment of the organic EL device. As shown in FIG. 2B, the organic EL device 20' includes, in addition to the face seal layer 28, a resin cured layer 28-1 containing a cured product of the sealing material of the present invention, and a passivation layer 28-2 covering the cured resin layer 28-1. The second resin cured layer 28-3 covering the passivation layer 28-2 is formed in substantially the same manner as in FIG. 2A. The other constituent members of the organic EL device 20' shown in Fig. 2B are the same as those of the organic EL device 20 shown in Fig. 2A.

The resin cured layer 28-1 contained in the surface seal layer 28 is preferably in contact with the organic EL element. The thickness of the resin cured layer 28-1 is preferably from 0.1 μm to 20 μm.

The passivation layer 28-2 contained in the surface sealing layer 28 is preferably formed in a plasma environment. An inorganic compound layer of the film. The film formation in a plasma environment is, for example, a film formed by a chemical vapor deposition (CVD) method, and is not particularly limited, and may be formed by a sputtering method or a vapor deposition method. The material of the passivation layer 28-2 is preferably a transparent inorganic compound, and examples thereof include cerium nitride, cerium oxide, SiONF, and SiON, and are not particularly limited. The thickness of the passivation layer 28-2 is preferably from 0.1 μm to 5 μm.

The passivation layer 28-2 may be formed in contact with the resin cured layer 28-1. The reason is that the resin cured layer 28-1 containing the cured product of the sealing material of the present invention maintains its transparency even when exposed to a plasma environment.

The passivation layer 28-2 is preferably not in direct contact with the organic EL element 24, but is formed in direct contact with the resin cured layer 28-1. When the passivation layer 28-2 is brought into direct contact with the organic EL element 24 to form a film, since the end portion of the organic EL element 24 is at an acute angle, the coverage due to the passivation layer 28-2 may be lowered. On the other hand, when the organic EL element 24 is hermetically sealed by the resin cured material layer 28-1 which is a cured product of the sealing material of the present invention, the passivation layer 28-2 is formed on the cured resin layer 28-1. Then, the film formation surface of the passivation layer 28-2 can be made gentle, and the coverage can be improved.

The second resin cured material layer 28-3 contained in the surface seal layer 28 may be the same material as the resin cured material layer 28-1 (layer containing the cured product of the sealing material of the present invention), or may be a different material. For example, the moisture content of the second resin cured layer 28-3 may sometimes be higher than the moisture content of the resin cured layer 28-1. The reason is that the second resin cured layer 28-3 is not in direct contact with the organic EL element. In addition, when it is a top emission type organic EL device (the organic EL device that emits light of the organic EL element through the second resin cured material layer 28-3), the light transmittance of the second resin cured material layer 28-3 must be the same as that of the resin. The cured layer 28-1 is also high.

The organic EL device can be produced by any method and can be manufactured by the following steps: 1) a step of preparing a substrate on which an organic EL element is disposed; 2) covering the organic EL element with a sealing material, and hardening the sealing material to form a surface a step of sealing the layer; 3) a step of sealing by sealing the substrate.

Fig. 3 is a schematic view showing an example of a manufacturing process of the organic EL device of Fig. 2A. First, the substrate 22 in which the organic EL element 24 is laminated is prepared (see FIG. 3A). The organic EL element 24 includes a reflective pixel electrode layer 30, an organic EL layer 32, and a transparent counter electrode layer 34, and may have other functional layers. Then, the liquid sealing material 28-1' of the present invention is applied onto the organic EL element 24, or the sheet-like sealing material 28-1' is laminated on the organic EL element 24 (see FIG. 3B). Then, the sealing substrate 26 is stacked, and the sealing material is cured in the above state to form the resin cured material layer 28-1, and the sealing substrate 26 is bonded (see FIG. 3C). The organic EL device 20 is thus obtained.

The organic EL device can be further manufactured by a step of exposing the surface sealing layer to the plasma as needed.

Examples of the step of exposing the face seal layer to the plasma include a step of forming a passivation film by plasma CVD on the face seal layer, or a step of irradiating the face seal layer with plasma to change surface characteristics, and the like. By changing the surface characteristics (for example, improving the wettability), the adhesion to other members can be improved.

As described above, only a part of the sealing member of the organic EL device can be used as a cured product of the sealing material. For example, as another aspect of the organic EL device, a form including the following members: 1) an organic EL element disposed on a substrate 2) a first resin cured layer that is in contact with the organic EL element and covers (seals) at least a part of the side surface of the organic EL element; 3) is in contact with the organic EL element, and covers (face seals) the upper surface of the organic EL element a second resin cured layer of at least a portion of the surface; 4) a sealing substrate covering the first cured resin layer and the second cured resin layer (see FIG. 4A). The first resin cured layer may be a cured product of the sealing material.

4A is a schematic cross-sectional view showing another embodiment of the organic EL device, and FIG. 4B is a plan view showing a state in which the sealing substrate 26 of the organic EL device 20" of FIG. 4A is removed. As shown in FIG. 4A, the organic EL device 20" has a face seal layer 28, and a dam material 36 covering the outer periphery thereof; the face seal layer 28 further includes a first seal layer 28A covering the side surface of the organic EL element 24, and a second cover covering the upper surface of the organic EL element 24. The sealing layer 28B is configured substantially the same as that of FIG. 2A. The other constituent members of the organic EL device 20" shown in FIG. 4A and FIG. 4B are the same as those of the organic EL device 20 shown in FIG. 2A.

The barrier material 36 is not particularly limited and may include an epoxy resin or the like. Such a barrier material 36 can be formed by coating or dropping by means of a dispenser.

The second sealing layer 28B is preferably free from water-absorbing fillers, fillers, and the like. The reason is that the upper surface of the organic EL element is not in contact with the water-absorbent filler, the filler, or the like, as described later, and thus damage (scratches) of the organic EL element can be suppressed. Another reason is that the second sealing layer 28B containing no water-absorbent filler, filler or the like tends to increase the total light transmittance, and is excellent in transparency.

The second sealing layer 28B has a parallel light transmittance of 400 nm Good is over 90%. The reason is that if the parallel light transmittance is too low, the light extraction efficiency from the element or the light absorption efficiency on the element is liable to lower. The upper limit of the light transmittance of the cured layer 28 can be, for example, about 99%. One of the methods for increasing the transmittance of parallel light is to contain no filler or to be 10% by mass or less.

Such a face seal layer 28 can be, for example, 1) coated with the seal member and hardened to form the first seal layer 28A in a manner to cover the side surface of the organic EL element; 2) to cover the upper surface of the organic EL element The surface is formed by applying a step of coating another sealing material and hardening to form the second sealing layer 28B. The coating of the sealing material constituting the first sealing layer 28A can be performed, for example, by a dispenser method or an inkjet method; and the coating of the sealing material constituting the second sealing layer 28B can be performed by a screen printing method or an inkjet method. get on.

In the organic EL device having such a configuration, since the side surface of the organic EL element is covered with the cured material of the sealing material, the permeation of moisture or oxygen in the atmosphere can be highly suppressed. In addition, since the upper surface of the organic EL element is covered with a cured product of another sealing material that does not contain a water-absorbent filler or a filler, it is possible to suppress damage (scratch) of the organic EL element due to a water-absorbent filler, a filler, or the like. And can also ensure transparency. That is, it is possible to achieve both low moisture permeability, transparency, and scratch resistance.

Example

Hereinafter, the present invention will be described with reference to the embodiments. The scope of the invention is not to be construed as limited by the embodiments.

[Example 1]

The following formula of the polyolefin-based polymer (A) containing a polymerizable functional group (A1) a compound (Kuraprene (registered trademark) UC-102, manufactured by Kuraray Co., Ltd., having a number average molecular weight of 17,000, and a radically polymerizable average functional group in one molecule = 2) 54 parts by mass; 46 parts by mass of dicyclopentenyloxyethyl acrylate (FA-512AS, manufactured by Hitachi Chemical Co., Ltd.) represented by the following formula (B1) as the polymerizable monomer (B); (C) a hexahydrophthalic anhydride derivative (C') (4-META-H, manufactured by Nippon Seika Co., Ltd.) represented by the following formula (C1): 10 parts by mass; as a radical polymerization initiator 5 parts by mass of a third ester of peroxy-2-ethylhexanoate (Luperox 575, manufactured by Arkema Yoshitomi Co., Ltd.) represented by the following formula (D1), and prepared to be sealed material.

[化10]

[Comparative Example 1]

A sealing material was prepared in the same manner as in Example 1 except that the hexahydrophthalic anhydride derivative (C') was not contained and the composition ratio shown in Table 1 was used.

[Comparative Example 2]

Instead of the hexahydrophthalic anhydride derivative (C'), use Nippon Physicochemical Manufacturing, RIKACID MH700 (4-methylhexahydrophthalic anhydride / hexahydrophthalic anhydride ( A sealing material was prepared in the same manner as in Example 1 except that the mixture ratio of the mass ratio = 70/30) was set to the composition ratio shown in Table 1.

[Evaluation]

The viscosity of the sealing material prepared in each of the examples and the comparative examples was measured. And borrow The light transmittance, the moisture permeability, and the elastic modulus of the cured product of the sealing material were measured by the following methods. The results are shown in Table 1.

. Viscosity

The viscosity of the sealing material at 25 ° C and 1.0 rpm was measured by an E-type viscometer (digital rheometer model DII-III ULTRA manufactured by BROOKFIELD).

. Parallel light transmittance

As background information, the parallel light transmittance of a wavelength region (visible light, ultraviolet light) of an alkali-free glass plate of 190 nm to 800 nm was measured using an ultraviolet-visible spectrophotometer (Shimadzu Corporation UV-2550).

The Teflon sheet (thickness: 100 μm) is sandwiched between the ends of the alkali-free glass plate by sandwiching the sealing material with the same two alkali-free glass plates, thereby holding the two alkali-free glass plates. The thickness of the sealing material was set to 100 μm. This was hardened by heating at 100 ° C for 30 minutes to obtain a cured product of a sealing material having a thickness of 100 μm.

The parallel light transmittance in the wavelength region of 190 nm to 800 nm of the cured product of the sealing material sandwiched between the two alkali-free glass plates was measured by an ultraviolet-visible spectrophotometer (Shimadzu Corporation UV-2550). In addition, since the Teflon sheet is disposed at the end of the glass sheet, it does not affect the measurement result.

Then, from the measurement result of the light transmittance of the cured product of the sealing material, the transmittance of the alkali-free glass plate as the background material was subtracted, and the parallel light transmittance of the cured product of the sealing material was calculated.

The evaluation was carried out by parallel light transmittance at a wavelength of 400 nm.

. Moisture permeability (Ca method)

1) Production of samples

A glass substrate (size: 25 mm × 25 mm, thickness: 0.7 mm) which was immersed in acetone and subjected to ultrasonic cleaning for 10 minutes was prepared. On the glass substrate, a vapor deposition film of metal calcium having a thickness of 170 nm was formed under the following conditions using a vapor deposition machine (manufactured by ALS Technology Co., Ltd.) (see FIG. 1A). A mask was used for vapor deposition, and the length L from the end of the vapor deposited film of the metal calcium to the end of the glass substrate was set to 4 mm.

(evaporation conditions)

Vacuum degree during vapor deposition: 3.0 × 10 ^-5 Pa

Film forming speed: 1.2 Å / sec

Metal Calcium Raw Material: High Purity Chemical Manufacturing, Granules

The obtained glass substrate with the metal calcium-deposited film was moved to a glove box of an N ₂ atmosphere without being exposed to the air. Then, on the separately prepared acetone-cleaned glass substrate (25 mm × 55 mm, thickness: 2 mm), the sealing material produced in the examples and the comparative examples was dropped so that the thickness after curing became 100 μm, and then dried. A coating film is formed (refer to FIG. 1B).

Then, a glass substrate with a coating film of a sealing material and a glass substrate with a vapor deposited film of metal calcium adhered to each other to form a laminate, which is fixed by a jig. The thickness of the obtained laminate is carried out by sandwiching a Teflon (registered trademark) sheet having a thickness of 100 μm between the glass substrate to which the coating film of the sealing material is applied and the glass substrate having the deposited film of metal calcium as a spacer. Adjustment. In addition, the length L' from the end of the vapor deposited film of the metal calcium to the end of the coating film of the sealing material was also 4 mm (see FIG. 1C).

Then, the laminate was cured by heating the laminate at 100 ° C for 30 minutes in an oven to prepare a sample. In either case, the cured sealing material is in the form of a film.

2) Determination of the start time of Ca reaction

The resulting sample was stored at 60 ° C and 90% RH in a constant temperature and humidity chamber. Then, the time until the end of the vapor-deposited film of the metal calcium was changed from the metallic luster to the transparent (Ca reaction start time, unit: hour) was measured. In the Ca method, the moisture permeability in the side direction of the cured product from the film-like sealing material was evaluated. Further, the case where the Ca reaction start time is 24 hours or longer is ○, and the case where the Ca reaction start time is less than 24 hours is ×.

. Elastic modulus

The sealing material was cured by heating at 100 ° C for 30 minutes to obtain a cured product having a thickness of 100 μm. The cured product of the obtained sheet was cut out to have a size of 10 mm × 30 mm. The test was carried out on a universal tensile tester manufactured by Intesco, with a distance of 30 mm between the chucks, and the test was carried out at an initial load of 10 N and a tensile speed of 30 mm/min. The elastic modulus is calculated from the slope of the straight line portion of the stress-strain curve in which the stress is taken on the vertical axis and the strain is taken on the horizontal axis.

As shown in Table 1, the olefin-based polymer (A), the polymerizable monomer (B), the hexahydrophthalic anhydride derivative (C'), and the radical polymerization containing a polymerizable functional group are included. In the sealing material of Example 1 of the initiator (D), the Ca reaction start time was extremely long. Since the hexahydrophthalic anhydride derivative (C') has a radical polymerizable functional group, when the sealing material is hardened, the polymerizable monomer (B) or the olefin-based polymer containing a polymerizable functional group is used. (A) and other polymerizations. As a result, since the structure derived from the hexahydrophthalic anhydride derivative (C') (an acid anhydride group) is uniformly contained in the cured product of the sealing material, it is estimated that the intrusion of the side surface of the cured material from the sealing material is effectively captured. Moisture.

Further, in the sealing material of Example 1, the modulus of elasticity was sufficiently as low as 17 MPa. In this case, since the hexahydrophthalic anhydride derivative (C') has a radically polymerizable functional group, the polymerizable monomer (B) and the olefin having a polymerizable functional group are hardened at the time of curing of the sealing material. Polymerization (A), etc., so it is estimated that the sealing material is hard. The crosslink density of the compound is not excessively increased, and the elastic modulus is moderately low.

On the other hand, in the sealing material of Comparative Example 2, although 4-methylhexahydrophthalic anhydride or hexahydrophthalic anhydride was contained, the Ca reaction start time was short. Since 4-methylhexahydrophthalic anhydride or hexahydrophthalic anhydride permeates from the cured product of the sealing material, it is presumed that the water cannot be sufficiently captured.

Further, the cured products of the sealing materials of Comparative Example 1 and Comparative Example 2 had an elastic modulus of 38 MPa or more. It is estimated that the crosslinking density of the olefin-based polymer (A) or the polymerizable monomer (B) containing a polymerizable functional group is improved.

[Embodiment 2]

The compound represented by the following formula (B2) which is a polymerizable monomer (B) (FA-124AS, manufactured by Hitachi Chemical Co., Ltd., the number average molecular weight is 198, and the average number of functional groups of radically polymerizable in one molecule = 2 80 parts by mass; hexahydrophthalic anhydride derivative (C') represented by the above formula (C1) as an acid anhydride derivative (C) (4-META-H, manufactured by Nippon Seika Co., Ltd.) 20 mass 5 parts by weight of the third ester of peroxy-2-ethylhexanoate (Luperox 575, manufactured by Arkema Jifu Co., Ltd.) represented by the above formula (D1) as a radical polymerization initiator Mix and prepare a sealing material.

[Example 3]

Instead of the third amyl ester of peroxy-2-ethylhexanoate, 2,2'-azobis-2-methylbutyronitrile represented by the following formula (D2) was used, and the examples were 2 A sealing material was prepared in the same manner.

[Example 4]

In place of the third pentyl peroxy-2-ethylhexanoate, 2-hydroxy-2-methyl-1-phenyl-propan-1-one represented by the following formula (D3) is used, and A sealing material was prepared in the same manner as in Example 2.

[Chemistry 14]

[Comparative Example 3]

Instead of the hexahydrophthalic anhydride derivative (C'), RikkAID MH700 (4-methylhexahydrophthalic anhydride/hexahydrophthalic anhydride) (manufactured by Nippon Chemical Co., Ltd.) was used. A sealing material was prepared in the same manner as in Example 2 except that the mixture of mass ratio = 70/30).

[Comparative Example 4]

In place of the third amyl ester of 2-ethylhexanoic acid peroxide, the same as in Comparative Example 3 except that 2,2'-azobis-2-methylbutyronitrile represented by the formula (D2) was used. The way to prepare the sealing material.

[Comparative Example 5]

Instead of the third amyl ester of peroxy-2-ethylhexanoate, 2-hydroxy-2-methyl-1-phenyl-propan-1-one represented by the formula (D3) is used, in addition to The sealing material was prepared in the same manner as in Comparative Example 3.

[Comparative Example 6]

Epoxy resin (cresol novolac type Epiclon (registered trademark) N-680, epoxy equivalent 200 (g/eq)-220 (g/eq), inkjet in Japan (manufactured by Dainippon Ink and Chemicals, DIC) 50 parts by mass; high purity liquid epoxy resin (bisphenol F type, YL983U0, epoxy equivalent of 165 (g/eq) - 175 (g/eq), Mitsubishi 50 parts by mass produced by Chemical Company; cerium oxide filler (Admafine SO-C6, manufactured by ADMATECHS) 100 parts by mass; photocationic initiator R2074 (Rhone - Sealing material was prepared by mixing 3 parts by mass of a product manufactured by Rhone-Poulenc.

[Evaluation]

. Parallel light transmittance

In the case of thermal hardening, the sealing material held by the two alkali-free glass plates is cured by heating at 80 ° C for 30 minutes, and irradiated with ultraviolet light (Ultraviolet, UV) at a wavelength of 365 nm of 3000 mJ/cm ² . The light was hardened to obtain a cured product of a sealing material having a thickness of 100 μm, and the measurement was carried out in the same manner as the measurement method of the parallel light transmittance of the above (Example 1 and the like).

. Moisture permeability (Ca method)

The moisture permeability (Ca) was measured in the same manner as in the above (Example 1 and the like). Then, the measurement sample was subjected to heat treatment at 100 ° C for 30 minutes, and the moisture permeability was evaluated in the same manner as described above.

As shown in Table 2, in Examples 2 to 4 containing the polymerizable monomer (B), the hexahydrophthalic anhydride derivative (C'), and the radical polymerization initiator (D) In the sealing material, the Ca reaction start time is very long. Since the hexahydrophthalic anhydride derivative (C') has a radically polymerizable functional group, it is polymerized with the polymerizable monomer (B) at the time of hardening of the sealing material, and is uniform in the cured product of the sealing material. Since the structure (an acid anhydride group) derived from the hexahydrophthalic anhydride derivative (C') is contained, it is estimated that the moisture invaded from the side surface of the cured product of the sealing material is effectively captured. Further, the Ca reaction start time did not change even if heat treatment was performed. Due to hexahydrophthalic anhydride derivatives Since (C') is polymerized with the polymerizable monomer (B), it is presumed that it does not bleed out.

On the other hand, in the sealing materials of Comparative Examples 3 to 5, although 4-methylhexahydrophthalic anhydride or hexahydrophthalic anhydride was contained, the Ca reaction start time was short. Since 4-methylhexahydrophthalic anhydride or hexahydrophthalic anhydride permeates from the cured product of the sealing material, it is presumed that the water cannot be sufficiently captured.

Further, the sealing material containing the epoxy resin of Comparative Example 6 had a long Ca reaction start time, that is, the water permeability was extremely low, but the viscosity was very high and the parallel line transmittance was low. On the other hand, in the sealing materials of Examples 2 to 4, it was confirmed that the viscosity was low, and coating by, for example, an inkjet method was also possible. In addition, the parallel light transmittance is also as high as 98%.

The present application claims priority based on Japanese Patent Application No. 2014-094957, filed on May 2, 2014. The contents described in the specification and drawings of the application are all incorporated in the specification of the present application.

[Industrial availability]

The cured product of the sealing material of the present invention has a low moisture permeability and a moderately low modulus of elasticity. Therefore, it can be applied to a sealing layer of various optical devices.

Claims (12)

A sealing material comprising: a polymerizable monomer (B) having at least one radical polymerizable functional group in each molecule, having a molecular weight of 50 or more and 1,000 or less, liquid at 23 ° C; an acid anhydride derivative (C) comprising, in each molecule, at least one anhydride group constituting a five-membered or six-membered ring, and a radical polymerizable functional group; a radical polymerization initiator (D) comprising a thermal radical polymerization initiation At least one of a agent and a photoradical polymerization initiator. The sealing material according to claim 1, further comprising: an olefin-based polymer (A) having a polymerizable functional group, having at least one radical polymerizable functional group per molecule, and a number average molecular weight It is 5000 or more and 70,000 or less. The sealing material according to claim 1, wherein the viscosity measured by an E-type viscometer at 25 ° C, 1.0 rpm is 5 mPa. Above s, 20000mPa. s below. The sealing material according to claim 1, wherein the polymerizable monomer (B) and the radical polymerizable functional group of the acid anhydride derivative (C) are independently selected One or more functional groups of a group consisting of a free (meth) acrylonitrile group, a vinyl group, an allyl group, and a vinyl ether group. The sealing material according to claim 2, wherein the polymerizable functional group-containing olefin-based polymer (A) has the radical polymerizable functional group selected from (meth) propylene. Mercapto group, vinyl group, allyl group, vinyl ether group More than one functional group of the group. The sealing material according to claim 2, wherein the acid anhydride derivative (C) is a hexahydrophthalic anhydride derivative having at least one radically polymerizable functional group per molecule (C) '). A sheet-like sealing material obtained by the sealing material according to claim 1 of the patent application. A cured material of a sealing material, which is a sealing material as described in claim 1 of the patent application. The cured product of the sealing material according to the second aspect of the invention, wherein the elastic modulus is 0.1 MPa or more and 100 MPa or less. The cured product of the sealing material according to claim 8, wherein the parallel light transmittance at a wavelength of 400 nm is 90% or more. The cured product of the sealing material according to claim 9, wherein the parallel light transmittance at a wavelength of 400 nm is 90% or more. A sealing material comprising: an olefin-based polymer (A) having a polymerizable functional group, having at least one radical polymerizable functional group per molecule, and having a number average molecular weight of 5,000 or more and 70,000 or less; hexahydroortho A phthalic anhydride derivative (C') having at least one radical polymerizable functional group in each molecule; a radical polymerization initiator (D) comprising a thermal radical polymerization initiator and photoradical polymerization At least one of the initiators.