JP6680295B2 - Sealing resin composition - Google Patents

Description

  The present invention relates to a sealing resin composition, a sealing sheet and the like, and particularly relates to a sealing resin composition, a sealing sheet and the like which can be suitably used for sealing an organic EL element and the like.

  An organic EL (Electroluminescence) element is a light-emitting element that uses an organic substance as a light-emitting material, and is a material that has recently been in the spotlight because it can emit light with high brightness at low voltage. However, the organic EL element is extremely vulnerable to moisture, and the organic material itself deteriorates due to moisture, resulting in a decrease in luminance, no emission of light, peeling of the interface between the electrode and the organic EL layer due to moisture, Since there is a problem that the metal of (3) is oxidized and the resistance is increased, the organic EL element is sealed.

  When the thermosetting resin composition is used as a material for encapsulating the entire surface of a substrate having an organic EL element, the viscosity of the material before curing is low, so that the laminating work is easy and the cured product of the cured product after heat curing is resistant to penetration. The advantage is high wettability. However, on the other hand, there is a problem that the organic EL element deteriorates due to the heating temperature during thermosetting.

  As a method of avoiding the thermal deterioration of the organic EL element, a method of using a pressure sensitive adhesive as a sealing material can be mentioned. For example, in Patent Document 1, a polyisobutylene resin, a polyisoprene resin and / or polyisobutylene resin having a functional group capable of reacting with an epoxy group, a tackifying resin, and a resin composition containing an epoxy resin are used for sealing. The technology is disclosed. Further, Patent Document 2 discloses a technique of sealing with a resin composition containing a styrene-isobutylene modified resin and a tackifying resin.

International publication 2011/062167 pamphlet International publication 2013/108731 pamphlet

  When a pressure-sensitive adhesive layer is formed on a support to form a sealing sheet, the moisture permeation resistance becomes a more important issue than in the case of using a thermosetting resin composition. In particular, higher moisture permeation resistance is required for sealing applications such as organic EL devices. Further, there is a problem that the adhesive strength of the pressure-sensitive adhesive to the substrate due to moisture absorption after sealing is also a problem, and improvement in adhesive moist heat resistance has been desired. Therefore, the problem to be solved by the present invention is to provide a resin composition for encapsulation which is excellent in adhesive moisture heat resistance and moisture permeability resistance.

  As a result of intensive studies for solving the above problems, the present inventor has found that (A) a (meth) acrylic acid alkyl ester and a polyolefin resin modified with an acid anhydride, (B) an epoxy resin, and (C) a tackifying resin. The encapsulating resin composition characterized by containing, a good cross-linking structure is formed by heating before encapsulation, adhesive moist heat resistance, to be a pressure-sensitive adhesive composition excellent in moisture permeability. Heading out, the present invention has been completed.

That is, the present invention includes the following aspects.
[1] A sealing resin containing (A) a (meth) acrylic acid alkyl ester and a polyolefin resin modified with an acid anhydride, (B) an epoxy resin, and (C) a tackifying resin. Composition.
[2] A graft polymer in which a polyolefin resin modified with (A) (meth) acrylic acid alkyl ester and an acid anhydride contains a (meth) acrylic acid alkyl ester unit and an acid anhydride unit in the main chain of the polyolefin resin. The modified resin composition for sealing according to the above [1], which is a graft modified product in which the number average molecular weight of the graft polymer is 100 or more.
[3] (A) The alkyl group of the (meth) acrylic acid alkyl ester in the polyolefin resin modified with the (meth) acrylic acid alkyl ester and the acid anhydride has 1 to 18 carbon atoms. ] Or the resin composition for closure as described in [2].
[4] (A) The concentration of the acid anhydride group in the polyolefin resin modified with the (meth) acrylic acid alkyl ester and the acid anhydride is 0.05 to 10 mmol / g, and the above [1] to [3] The resin composition for encapsulation according to any one of 1.
[5] The encapsulating resin composition according to any one of the above [1] to [4], wherein the (B) epoxy resin is an epoxy-modified polyolefin-based resin.
[6] The encapsulating resin composition according to the above [5], wherein the epoxy-modified polyolefin resin has an epoxy group concentration of 0.05 to 10 mmol / g.
[7] The total content of the (A) (meth) acrylic acid alkyl ester, the polyolefin resin modified with an acid anhydride, and the (B) epoxy resin is such that the nonvolatile content in the resin composition is 100% by mass. In this case, the encapsulating resin composition according to any one of the above [1] to [6], which is 5 to 80 mass%.
[8] Any one of the above [1] to [7], in which the content of the tackifying resin (C) is 5 to 80% by mass when the nonvolatile content in the resin composition is 100% by mass. The resin composition for encapsulation according to 1.
[9] An ester bond formed by the reaction of the acid anhydride group of the polyolefin resin (A) modified with the (meth) acrylic acid alkyl ester and the acid anhydride and the epoxy group of the epoxy resin (B) is formed. , The encapsulating resin composition according to any one of the above [1] to [8].
[10] The encapsulating resin composition according to any one of the above [1] to [9], which is for encapsulating an organic EL element.
[11] A sealing sheet having an adhesive layer formed on a support, wherein the adhesive layer is formed by the sealing resin composition according to any one of the above [1] to [9]. The encapsulating sheet.
[12] The encapsulating sheet according to the above [11], which is used for encapsulating an organic EL element.
[13] An organic EL device in which an organic EL element is sealed by a sealing layer, wherein the sealing layer is the resin composition for sealing according to any one of [1] to [10] above. An organic EL device that is formed by a product.
[14] An organic EL device in which an organic EL element is sealed by a sealing layer, wherein the sealing layer is formed by the adhesive layer of the sealing sheet according to [11] or [12] above. Are organic EL devices.
[15] A resin varnish containing the encapsulating resin composition according to any one of the above [1] to [9] is applied on a support and dried by heating to give (A) an alkyl (meth) acrylate. Production of a sealing sheet, characterized in that an acid anhydride group of a polyolefin resin modified with an ester and an acid anhydride and an epoxy group of an epoxy resin (B) are reacted to form an ester-bonded adhesive layer. Method.

  ADVANTAGE OF THE INVENTION According to this invention, the resin composition for sealing excellent in adhesive moisture heat resistance and moisture resistance, the sheet | seat for sealing obtained from it, and the organic EL device sealed by this resin composition for sealing are provided. To be done.

Hereinafter, the present invention will be described in detail.
The encapsulating resin composition of the present invention (hereinafter, also simply referred to as “resin composition”) is (A) a (meth) acrylic acid alkyl ester-modified polyolefin resin, and (B) an epoxy resin. The main characteristic is that the resin and (C) the tackifying resin are contained.

<(A) Polyolefin resin modified with (meth) acrylic acid alkyl ester and acid anhydride>
In the resin composition of the present invention, a polyolefin resin modified with an alkyl (meth) acrylate and an acid anhydride (hereinafter, may be referred to as "modified polyolefin resin" or "(A) component"). Is used.

(Polyolefin resin)
The polyolefin resin of the main skeleton (skeleton excluding the modifying component) of the modified polyolefin resin used in the present invention is not particularly limited as long as it has a skeleton derived from an olefin monomer. For example, polyethylene resin, polypropylene resin, polybutene resin, polyisobutylene resin, etc. may be mentioned. Among them, polyethylene resins, polypropylene resins and polybutene resins are preferable, and polyethylene resins and polypropylene resins are particularly preferable. The polyethylene-based resin here is a homopolymer of ethylene, or at least ethylene and a monomer other than ethylene, in which the main monomer unit (monomer unit exceeding 50% by mass) is ethylene. It means a copolymer containing a monomer unit (for example, an olefin other than ethylene, a non-conjugated diene, a monomer unit such as (meth) acrylic acid alkyl ester), and the polypropylene resin is a homopolymer of propylene, Alternatively, at least propylene and a monomer unit other than propylene (for example, an olefin other than propylene, a non-conjugated diene, (meth)) in which a main monomer unit (monomer unit of more than 50% by mass) is propylene. A polybutene-based resin is a homopolymer of butene, or a copolymer containing a monomer unit such as an acrylic acid alkyl ester). Is at least butene and a monomer unit other than butene (for example, an olefin other than butene, a non-conjugated diene, (meth)) in which the main monomer unit (monomer unit of more than 50% by mass) is butene. A polyisobutylene-based resin means a homopolymer of isobutylene or a main monomer unit (a monomer unit of more than 50% by mass). ) Is isobutylene, a copolymer containing at least isobutylene and a monomer unit other than isobutylene (for example, an olefin other than isobutylene, a non-conjugated diene, a monomer unit such as a (meth) acrylic acid alkyl ester). means.
For example, from the viewpoint of processability and the embeddability of the adhesive layer when the resin composition is used as the adhesive layer of the encapsulating sheet, the polyethylene resin is superior to the polypropylene resin. Here, the "processability" is particularly the processability when the modified polyolefin resin is formed on the film (layer), and the fluidity of the resin varnish for enabling the film (layer) formation is maintained (temporarily). Stability) etc. On the other hand, from the viewpoint of heat resistance, polypropylene resin is superior to polyethylene resin.

  For reasons such as making the polyolefin resin more preferable, it is preferable to use a copolymer such as a random copolymer or a block copolymer for the polyolefin resin. As the copolymer, (i) a copolymer of two or more kinds of olefins, (ii) a copolymer of an olefin and a non-conjugated diene, or (iii) a monomer other than an olefin such as styrene (a non-conjugated diene Except) and copolymers. Here, in the copolymer (ii) and the copolymer (iii), one kind or two or more kinds of olefins can be used.

Specific examples of the copolymer in the polyolefin resin include, for example, ethylene-non-conjugated diene copolymer, ethylene- (meth) acrylic acid alkyl ester copolymer, ethylene-butene copolymer, ethylene-butene-non-conjugated. Diene copolymer, ethylene-butene- (meth) acrylic acid alkyl ester copolymer, ethylene-propylene copolymer, ethylene-propylene-non-conjugated diene copolymer, ethylene-propylene-butene copolymer, ethylene-propylene -(Meth) acrylic acid alkyl ester copolymer, propylene-non-conjugated diene copolymer, propylene- (meth) acrylic acid alkyl ester copolymer, propylene-butene copolymer, propylene-butene-non-conjugated diene copolymer Combined, Propylene-Butene- (meth) acrylate alkyl ester Copolymer, isobutylene-non-conjugated diene copolymer, isobutylene- (meth) acrylic acid alkyl ester copolymer, isobutylene-butene copolymer, isobutylene-butene-non-conjugated diene copolymer, isobutylene-butene- (meth ) Acrylic acid alkyl ester copolymers, styrene-isobutylene copolymers, styrene-isobutylene-styrene copolymers and the like.
Among them, ethylene- (meth) acrylic acid alkyl ester copolymer, ethylene-butene copolymer, ethylene-butene- (meth) acrylic acid alkyl ester copolymer, ethylene-propylene copolymer, ethylene-propylene- ( (Meth) acrylic acid alkyl ester copolymer, ethylene-propylene-butene copolymer, propylene-butene copolymer, propylene-butene- (meth) acrylic acid alkyl ester copolymer, isobutylene-butene copolymer, isobutylene- Butene- (meth) acrylic acid alkyl ester copolymer and the like are preferable.

  In addition, the above-mentioned copolymer is described in a form in which the monomer components are described in parallel, and the form of the copolymer is not specified. That is, any copolymer may be a random copolymer or a block copolymer. Further, in the case of a block copolymer of a binary copolymer, the block copolymer may be a diblock copolymer or a triblock copolymer. That is, for example, a block copolymer of an ethylene-butene copolymer is a diblock copolymer composed of a polyethylene block (polyethylene skeleton) -polybutene block (polybutene skeleton) (a multiblock composed of alternating repeating polyethylene blocks and polybutene blocks). Block copolymer), polyethylene block (polyethylene skeleton) -polybutene block (polybutene skeleton) -polyethylene block (polyethylene skeleton) triblock copolymer, polybutene block (polybutene skeleton) -polyethylene block (polyethylene skeleton)- It includes a triblock copolymer composed of a polybutene block (polybutene skeleton). The same applies to binary copolymers other than the ethylene-butene copolymer.

  As the polyethylene-based resin, for example, from the viewpoint of improving heat resistance and the like, an ethylene-propylene copolymer, an ethylene-butene copolymer, an ethylene-propylene-butene copolymer, or the like can be used. Further, the propylene-based resin, for example, from the viewpoint of improving processability, embedding property, etc., a propylene-ethylene copolymer, a propylene-butene copolymer, an ethylene-propylene-butene copolymer can be used, Further, from the viewpoint of improving heat resistance, a propylene-butene copolymer can be used.

  The butene used in the present invention is not particularly limited, and examples thereof include 1-butene, cis-2-butene, trans-2-butene, isobutene (also referred to as 2-methylpropene), and these may be used alone or Two or more kinds can be used in combination, but 1-butene is preferable. When two or more butenes are used, for example, an ethylene-butene copolymer may be a copolymer of ethylene and two or more butenes, or the butene units are different from each other. It may be a mixture of two or more ethylene-butene copolymers of butene. The form of the ethylene-butene copolymer is not particularly limited, and may be a random copolymer or a block copolymer, but among them, from the viewpoint of improving processability, a random copolymer is preferable. Polymers are preferred.

  Other olefins (that is, olefins other than ethylene, propylene, butene, and isobutylene) that may be contained as a monomer unit of the polyolefin resin include 1-pentene, 3-methyl-1-hexene, and 3-methyl. Α having 2 to 11 carbon atoms such as -1-pentene, 4-methyl-1-pentene, 3-ethyl-1-pentene, 1-septene, 1-octene, 1-nonene, 1-decene, 1-undecene. -Olefins (excluding propylene and 1-butene) may be mentioned. Of these, 1-hexene is preferable. Such α-olefins may be used alone or in combination of two or more.

  Further, as other olefins, the number of carbon atoms such as methylhexadiene (2-methyl-1,5-hexadiene, 3-methyl-2,4-hexadiene, etc.), 1,9-decadiene, 1,13-tetradecadiene, etc. There may be mentioned 10 to 14 non-conjugated diolefin compounds. Among them, methylhexadiene is preferable, and 2-methyl-1,5-hexadiene is particularly preferable. Such non-conjugated diolefin compounds can be used alone or in combination of two or more.

  As the polyolefin resin of the main skeleton in the modified polyolefin resin of the present invention, a copolymer of olefin and (meth) acrylic acid alkyl ester can be used. The term “(meth) acrylic acid alkyl ester” as used herein means an acrylic acid alkyl ester and a methacrylic acid alkyl ester. Either or both of the acrylic acid alkyl ester and the methacrylic acid alkyl ester may be used. The alkyl group in the (meth) acrylic acid alkyl ester may be an unsubstituted alkyl group or a substituted alkyl group (for example, an aralkyl group), but an unsubstituted alkyl group is preferable. The group preferably has 1 to 20 carbon atoms, and more preferably 1 to 10 carbon atoms. Specific examples of the (meth) acrylic acid alkyl ester include, for example, methyl acrylate, ethyl acrylate, butyl acrylate, ethylhexyl acrylate, isobutyl acrylate, benzyl acrylate, phenoxyethyl acrylate, methyl methacrylate, methacrylic acid. Examples thereof include ethyl, butyl methacrylate, ethylhexyl methacrylate, isobutyl methacrylate, benzyl methacrylate, and phenoxyethyl methacrylate. Of these, methyl methacrylate is preferred. The (meth) acrylic acid alkyl ester can use 1 type (s) or 2 or more types.

  For example, in the modified polyolefin resin of the present invention, an ethylene-butene copolymer, an isobutylene-butene copolymer, a copolymer containing at least butene as a monomer unit such as a propylene-butene copolymer is a resin composition. From the viewpoint of the balance of performance such as adhesiveness and moisture permeation resistance, for example, in the case of an ethylene-butene copolymer, the content of ethylene units is preferably 20% by mass or more based on the entire copolymer, 30 mass% or more is more preferable, 40 mass% or more is still more preferable, and 50 mass% or more is the most preferable. For the same reason, it is preferably 95% by mass or less, and more preferably 90% by mass or less. The same applies to the content of isobutylene units in the isobutylene-butene copolymer and the content of propylene units in the propylene-butene copolymer.

  Further, in the modified polyolefin resin of the present invention, ethylene- (meth) acrylic acid alkyl ester copolymer, isobutylene- (meth) acrylic acid alkyl ester copolymer, propylene- (meth) acrylic acid alkyl ester copolymer, etc. The copolymer of olefin and (meth) acrylic acid alkyl ester containing at least (meth) acrylic acid alkyl ester as a monomer unit has a good balance of performance such as adhesiveness and moisture permeation resistance of the resin composition. From the viewpoint, for example, in the case of an ethylene- (meth) acrylic acid alkyl ester copolymer, the content of ethylene units is preferably 30% by mass or more, more preferably 40% by mass or more, based on the total amount of the copolymer, and 50 Even more preferably, it is at least mass%. For the same reason, it is preferably 95% by mass or less, and more preferably 90% by mass or less. The same applies to the content of isobutylene units in the isobutylene- (meth) acrylic acid alkyl ester copolymer, the content of propylene in the propylene- (meth) acrylic acid alkyl ester copolymer, and the like.

  In the modified polyolefin resin of the present invention, ethylene-butene copolymer, propylene-butene copolymer, isobutylene-butene copolymer and the like are further copolymerized with other olefins other than ethylene, propylene, isobutylene and butene. When the copolymer is used, the ratio of other olefin units may be the same as that of ethylene units, butene units and other units in order to take advantage of the characteristics such as ethylene units, propylene units, isobutylene units and butene units in the copolymer. The total amount of olefin units, the total amount of propylene units, butene units and other olefin units, or the total amount of isobutylene units, butene units and other olefin units is preferably 20% by mass or less, more preferably 10% by mass or less. It is particularly preferably 5% by mass or less, and most preferably 3% by mass or less.

  Further, in the modified polyolefin resin of the present invention, ethylene- (meth) acrylic acid alkyl ester copolymer, isobutylene- (meth) acrylic acid alkyl ester copolymer, propylene- (meth) acrylic acid alkyl ester copolymer, etc. In the case where a copolymer in which other olefins other than ethylene, propylene and isobutylene are further copolymerized is used, in order to take advantage of the characteristics of the ethylene unit, propylene unit, isobutylene unit and the like in the copolymer, other The ratio of the olefin unit is the total amount of the ethylene unit, the (meth) acrylic acid alkyl ester unit and the other olefin unit, the total amount of the propylene unit, the (meth) acrylic acid alkyl ester unit and the other olefin unit, or the isobutylene unit ( (Meth) acrylic acid alkyl ester butene unit and Respect of the total amount of olefin units, preferably 20 wt% or less, more preferably 10 wt% or less, especially preferably 5 mass% or less, and most preferably 3 wt% or less.

(Modified polyolefin resin)
The modified polyolefin-based resin in the present invention is a polyolefin-based resin modified with an alkyl (meth) acrylate and an acid anhydride from the viewpoint of imparting excellent physical properties such as adhesion wet heat resistance and moisture resistance. That is, the modified polyolefin resin in the present invention is a graft modified product in which a graft chain containing a unit derived from a (meth) acrylic acid alkyl ester and a unit derived from an acid anhydride is bonded to the main chain of the polyolefin resin. The term “(meth) acrylic acid alkyl ester” as used herein means an acrylic acid alkyl ester or a methacrylic acid alkyl ester, which may be used alone or as a mixture of an acrylic acid alkyl ester and a methacrylic acid alkyl ester. Good.

  The number of carbon atoms of the alkyl group in the (meth) acrylic acid alkyl ester is preferably 1-18, more preferably 1-14, still more preferably 1-12, particularly preferably 1-10, most preferably 1-8. . Specific examples of the (meth) acrylic acid alkyl ester include methyl acrylate, ethyl acrylate, n-propyl acrylate, i-propyl acrylate, n-butyl acrylate, i-butyl acrylate, 2-butyl acrylate. , T-butyl acrylate, cyclohexyl acrylate, 2-ethylhexyl acrylate, n-octyl acrylate, n-dodecyl acrylate, n-octadecyl acrylate, methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, methacryl I-Propyl acid, n-butyl methacrylate, i-butyl methacrylate, 2-butyl methacrylate, t-butyl methacrylate, cyclohexyl methacrylate, 2-ethylhexyl methacrylate, n-octyl methacrylate, n-dodecyl methacrylate. , Methacrylic n- octadecyl, benzyl acrylate, acrylic acid phenoxyethyl and the like. Among them, 2-ethylhexyl acrylate, n-butyl methacrylate and the like are preferable, and 2-ethylhexyl acrylate is more preferable. The (meth) acrylic acid alkyl ester can use 1 type (s) or 2 or more types.

  Examples of the acid anhydride include succinic anhydride, maleic anhydride, glutaric anhydride, and the like. Particularly preferred is succinic anhydride. The acid anhydride can use 1 type (s) or 2 or more types.

  The polyolefin-based resin modified with an alkyl (meth) acrylate and an acid anhydride is, for example, a polyolefin-based resin obtained by subjecting a polyolefin-based resin to an unsaturated compound having an acid anhydride group and an alkyl (meth) acrylate under radical reaction conditions. It is obtained by graft modification with an ester (see, for example, JP-A Nos. 2002-173514 and 2006-219627).

  The number average molecular weight of the graft chain (graft polymer) formed by the (meth) acrylic acid alkyl ester and the acid anhydride is preferably 100 or more, more preferably 200 or more, still more preferably 300 or more. When there is no modification with the (meth) acrylic acid alkyl ester (that is, when the graft chain does not contain the (meth) acrylic acid alkyl ester unit), it tends to be difficult to form a graft chain having an appropriate length. If the average value of the number average molecular weight of the graft chain (graft polymer) is too small, it tends to be difficult to form a crosslinked structure with an epoxy resin, particularly an epoxy-modified polyolefin resin. The upper limit of the average value of the number average molecular weight of the graft chain (graft polymer) is not particularly limited as long as the sealing performance of the resin composition of the present invention, adhesion wet heat resistance, moisture resistance and the like functions are exhibited, but generally Is 5000 or less, preferably 3000 or less. The graft chain (graft polymer) preferably contains 20% by weight or more and 80% by weight or less of an alkyl (meth) acrylate unit, more preferably 30% by weight or more and 70% by weight or less, and 40% by weight. It is more preferable that the content is 60 wt% or less.

  The number average molecular weight of the graft chain (graft polymer) can be determined by the viscosity of the graft-modified product, chemical structure analysis of the graft-modified product, and molecular weight measurement by gel permeation chromatography (GPC) method (converted to polystyrene). When a graft modified product is produced by radically polymerizing an alkyl (meth) acrylate and an acid anhydride in the presence of a polyolefin resin, the graft chain length is a free polymer that does not contribute to grafting to the polyolefin resin. The molecular weight of the polymer component which is not bonded to the main chain of the polyolefin-based resin and is formed only by the added (meth) acrylic acid alkyl ester and the acid anhydride is measured by the GPC method or the like. Therefore, it can be easily obtained. Specifically, the number average molecular weight measured by the GPC method is LC-9A / RID-6A manufactured by Shimadzu Corporation as a measuring device and Shodex K-800P / K-804L / K-804L manufactured by Showa Denko KK as a column. It can be calculated by using toluene or the like as a phase at a column temperature of 40 ° C. and using a calibration curve of standard polystyrene.

  As the component (A), one type may be used, or two or more types may be mixed and used. That is, it is possible to mix and use two or more kinds of graft modified products in which the polyolefin-based resin of the main skeleton and / or the graft polymer are different from each other.

  When the component (A) is a mixture of two or more graft modified products, the concentration and number average molecular weight of the acid anhydride group of the component (A) described below are values in the entire mixture of two or more graft modified products. Further, the number average molecular weight of the graft chain (graft polymer) is also the number average molecular weight of the total graft polymer contained in the mixture.

  The concentration of the acid anhydride group in the component (A) is preferably 0.05 to 10 mmol / g, more preferably 0.1 to 5 mmol / g. The concentration of the acid anhydride group is obtained from the value of the acid value defined as the number of mg of potassium hydroxide required to neutralize the acid present in 1 g of the resin, according to the description of JIS K 2501.

  The number average molecular weight of the component (A) is not particularly limited, but is preferably 500000 or less from the viewpoint of providing good coatability of the varnish of the resin composition and good compatibility with other components in the resin composition. , 300000 or less is more preferable, and 150,000 or less is further preferable. On the other hand, from the viewpoint of preventing cissing at the time of applying a varnish of the resin composition, developing moisture resistance of the formed resin composition layer, and improving mechanical strength, 10,000 or more is preferable, and 30,000 or more is more preferable. It is preferably 50,000 or more and more preferably. The number average molecular weight in the present invention is measured by a gel permeation chromatography (GPC) method (polystyrene conversion). The number average molecular weight measured by the GPC method is, specifically, LC-9A / RID-6A manufactured by Shimadzu Corporation as a measuring device and Shodex K-800P / K-804L / K-804L manufactured by Showa Denko KK as a column. It can be calculated by using toluene or the like as a phase at a column temperature of 40 ° C. and using a calibration curve of standard polystyrene.

  From the viewpoint of improving processability, the component (A) preferably has low crystallinity, and is particularly preferably amorphous. Here, non-crystalline means that the component (A) does not have a definite melting point, and for example, when the melting point of the component (A) is measured by DSC (differential scanning calorimetry), it is clear. That is, no peak is observed.

  The content of the component (A) in the resin composition of the present invention is not particularly limited, but it provides good coating properties and compatibility of the varnish of the resin composition, and good wet heat in the formed resin composition layer. From the viewpoint of ensuring durability and handleability (suppression of tack), when the nonvolatile content in the resin composition is 100% by mass, 45% by mass or less is preferable, 40% by mass or less is more preferable, and 35% by mass or less is More preferable. On the other hand, from the viewpoint of improving moisture permeability resistance and transparency, when the non-volatile content in the resin composition is 100% by mass, 5% by mass or more is preferable, 10% by mass or more is more preferable, and 15% by mass. % Or more is more preferable.

<(B) Epoxy resin>
The resin composition of the present invention contains an epoxy resin (hereinafter, also abbreviated as “(B) component”). The epoxy resin forms a crosslinked structure by the reaction with the acid anhydride group contained in the component (A). The epoxy resin is not particularly limited as long as it has two or more epoxy groups per molecule on average. For example, bisphenol A type epoxy resin, biphenyl type epoxy resin, biphenyl aralkyl type epoxy resin, naphthol type epoxy resin, naphthalene type epoxy resin, bisphenol F type epoxy resin, phosphorus-containing epoxy resin, bisphenol S type epoxy resin, aromatic glycidyl amine Type epoxy resin (for example, tetraglycidyl diaminodiphenylmethane, triglycidyl-p-aminophenol, diglycidyl toluidine, diglycidyl aniline), alicyclic epoxy resin, aliphatic chain epoxy resin, phenol novolac type epoxy resin, cresol novolac Type epoxy resin, bisphenol A novolac type epoxy resin, epoxy resin containing polyalkylene glycol skeleton, epoxy resin having butadiene structure, bispheno Diglycidyl ether compound of alcohol, diglycidyl ether compound of naphthalene diol, glycidyl ether compound of phenols, diglycidyl ether compound of alcohols, and alkyl substitution products, halides and hydrogenated products of these epoxy resins. To be Among the above epoxy resins, bisphenol A type epoxy resin, bisphenol F type epoxy resin, phenol novolac type epoxy resin, biphenyl aralkyl type epoxy resin, phenol aralkyl type epoxy resin, aromatic glycidyl amine type epoxy resin, and dicyclopentadiene structure are used. The epoxy resin and the polypropylene glycol skeleton-containing epoxy resin are preferable, and the bisphenol A type epoxy resin and the polypropylene glycol skeleton-containing epoxy resin are particularly preferable.

  Commercially available products of the epoxy resin include "828EL" (liquid bisphenol A type epoxy resin) manufactured by Mitsubishi Chemical Co., "HP4032", "HP4032D" manufactured by DIC (both are naphthalene type bifunctional epoxy resin), and "IC" manufactured by DIC. HP4700 "(naphthalene type tetrafunctional epoxy resin), DIC's" HP7200 series "(dicyclopentadiene type epoxy resin), Toto Kasei's" ESN-475V "," ESN-185V "(all are naphthol type epoxy resins). , "PB-3600" manufactured by Daicel Chemical Industries, Ltd. (epoxy resin having a butadiene structure), "NC3000H", "NC3000L", "NC3100", "NC3000", "NC3000FH-75M" manufactured by Nippon Kayaku Co. (both are biphenyl. Type epoxy resin), "Y" manufactured by Mitsubishi Chemical Corporation 4000 "(biphenyl type epoxy resin), manufactured by Japan Epoxy Resins Co., Ltd." YX8800 "(anthracene skeleton-containing epoxy resin), DIC Corporation" EPICLON EXA4850-1000 "(polypropylene glycol skeleton-containing epoxy resin), and the like.

  The epoxy resin may be liquid or solid, and both liquid and solid substances may be used. Here, "liquid" and "solid" are the epoxy resin states at room temperature (25 ° C). The component (B) preferably has an epoxy equivalent of 100 to 1500 g / eq, more preferably 150 to 1000 g / eq, and still more preferably 200 to 800 g / eq. The "epoxy equivalent" is the number of grams (g / eq) of a resin containing 1 gram equivalent of epoxy group, and is measured according to the method specified in JIS K7236.

  As the epoxy resin as the component (B), an epoxy-modified polyolefin resin, that is, a polyolefin resin having an epoxy group is particularly preferable. Examples of the epoxy-modified polyolefin-based resin include a graft-modified product in which a graft polymer containing a unit of an epoxy group-containing unsaturated compound is bonded to the main chain of the polyolefin-based resin. The graft modified product is obtained by graft modifying a polyolefin resin with an epoxy group-containing unsaturated compound under radical reaction conditions. Examples of the epoxy group-containing unsaturated compound include glycidyl (meth) acrylate, β-methylglycidyl (meth) acrylate, 4-hydroxybutyl acrylate glycidyl ether, 2-hydroxyethyl acrylate glycidyl ether, and allyl glycidyl ether. Glycidyl methacrylate is preferred. These can use 1 type (s) or 2 or more types. Specific examples of the polyolefin resin in the graft-modified product are the same as those exemplified as the specific examples of the polyolefin resin in the component (A).

  As the epoxy-modified polyolefin-based resin, one or two or more kinds selected from the above epoxy group-containing unsaturated compounds and one or more kinds of olefins are radically copolymerized to obtain an epoxy group-containing unsaturated compound. It may be obtained as a copolymer containing a compound unit and an olefin unit. Specific examples of the olefin include the same as those exemplified as the constituent monomer units of the polyolefin resin of the main skeleton in the modified polyolefin resin of the component (A).

  The epoxy group concentration in the epoxy-modified polyolefin resin is preferably 0.05 to 10 mmol / g, more preferably 0.1 to 5 mmol / g. The epoxy group concentration is determined from the epoxy equivalent obtained according to JIS K 7236-1995.

  The number average molecular weight of the epoxy modified polyolefin resin is not particularly limited, but from the viewpoint of providing good coatability of the varnish of the resin composition and good compatibility with other components in the resin composition, 500000 or less is preferable. It is preferably 300,000 or less, more preferably 150,000 or less. On the other hand, from the viewpoint of preventing cissing at the time of applying a varnish of the resin composition, developing moisture resistance of the formed resin composition layer, and improving mechanical strength, 10,000 or more is preferable, and 30,000 or more is more preferable. It is preferably 50,000 or more and more preferably. The number average molecular weight here is measured by a gel permeation chromatography (GPC) method (polystyrene conversion). The number average molecular weight measured by the GPC method is, specifically, LC-9A / RID-6A manufactured by Shimadzu Corporation as a measuring device and Shodex K-800P / K-804L / K-804L manufactured by Showa Denko KK as a column. It can be calculated by using toluene or the like as a phase at a column temperature of 40 ° C. and using a calibration curve of standard polystyrene.

  From the viewpoint of improving processability, the epoxy-modified polyolefin-based resin preferably has low crystallinity, and is particularly preferably amorphous. Here, non-crystalline means that the epoxy-modified polyolefin-based resin does not have a definite melting point, and for example, when the melting point is measured by DSC (differential scanning calorimetry) of the epoxy-modified polyolefin-based resin. That is, no clear peak is observed.

  The component (B) may be used alone or in combination of two or more. The content of the component (B) in the resin composition is not particularly limited, but from the viewpoint of ensuring good moisture permeation resistance, when the nonvolatile content in the resin composition is 100% by mass, 45% by mass or less Is preferred, 40% by mass or less is more preferred, and 35% by mass or less is even more preferred. On the other hand, from the viewpoint that good handling properties (tack suppression) can be ensured, when the nonvolatile content in the resin composition is 100% by mass, 5% by mass or more is preferable, 10% by mass or more is more preferable, and 15% by mass is 15% by mass. The above is more preferable.

  The amount ratio of the component (A) and the component (B) in the resin composition of the present invention is arbitrarily selected within a range in which the effects of the present invention are exhibited, but it forms a good crosslinked structure and exhibits unreacted activity. The ratio (Ea / Eb) of the acid anhydride equivalent (Ea) of the component (A) and the epoxy equivalent (Eb) of the component (B) from the viewpoint of reducing the content of various functional groups and stably exhibiting the performance. Is preferably 0.7 to 1.45, more preferably 0.8 to 1.25, still more preferably 0.9 to 1.15, and still more preferably 0.95 to 1.06. The "acid anhydride equivalent" is the number of grams (g / eq) of the resin containing 1 gram equivalent of acid anhydride group.

  In the resin composition of the present invention, the total content of the component (A) and the component (B) is not particularly limited, but from the viewpoint of adhesiveness, processability, etc., the nonvolatile content of the resin composition is 100% by mass. In that case, 80% by mass or less is preferable, 75% by mass or less is more preferable, and 70% by mass or less is further preferable. On the other hand, from the viewpoint of resistance to wet heat, when the nonvolatile content in the resin composition is 100% by mass, 5% by mass or more is preferable, 10% by mass or more is more preferable, and 15% by mass or more is further preferable.

<(C) Tackifying resin>
The tackifying resin (C) used in the present invention (hereinafter also abbreviated as “(C) component”) is also called a tackifier, and is a resin that is blended with a plastic polymer to impart tackiness. The component (C) is not particularly limited and includes terpene resins, modified terpene resins (hydrogenated terpene resins, terpene phenol copolymer resins, aromatic modified terpene resins, etc.), coumarone resins, indene resins, petroleum resins ( Aliphatic petroleum resin, hydrogenated alicyclic petroleum resin, aromatic petroleum resin, aliphatic aromatic copolymer petroleum resin, alicyclic petroleum resin, dicyclopentadiene petroleum resin and its hydride etc.) Preferably used.

  Among them, the adhesiveness of the resin composition, moisture resistance, compatibility, etc., terpene resin, aromatic modified terpene resin, terpene phenol copolymer resin, hydrogenated alicyclic petroleum resin, aromatic petroleum resin, Aliphatic aromatic copolymer-based petroleum resins, alicyclic-based petroleum resins are more preferred, alicyclic-based petroleum resins are more preferred, alicyclic saturated hydrocarbon resins are even more preferred, cyclohexane ring-containing saturated hydrocarbon resins, Dicyclopentadiene modified hydrocarbon resins are particularly preferred.

  Examples of commercially available products that can be used as the component (C) include terpene resins such as YS resin PX and YS resin PXN (both manufactured by Yasuhara Chemical Co., Ltd.), and aromatic modified terpene resins such as YS resin TO and TR series. Yasuhara Chemical Co., Ltd.), hydrogenated terpene resins such as CLEARON P, CLEARON M, CLEARON K series (all manufactured by Yasuhara Chemical Co., Ltd.), and terpene phenol copolymer resin YS Polystar 2000, Polystar U , Polystar T, Polystar S, Mighty Ace G (all manufactured by Yasuhara Chemical Co., Ltd.) and the like, and hydrogenated alicyclic petroleum resins include Escorez 5300 series, 5600 series (all manufactured by ExxonMobil) and the like. Group petroleum resin ENDEX 155 (manufactured by Eastman) and the like, Quintone D100 (manufactured by Nippon Zeon Co., Ltd.) and the like as an aliphatic aromatic copolymer-based petroleum resin, and Quintone 1325, Quintone 1345 (both in Japan Zeon) and the like, hydrogenated alicyclic petroleum resins such as Alcon P100, Alcon P125, Alcon P140 (all manufactured by Arakawa Chemical Co., Ltd.) and the like, and cyclohexane ring-containing saturated hydrocarbon resin such as TFS13-030 ( Arakawa Chemical Co., Ltd.) and the like.

  The softening point of the component (C) is preferably 50 to 200 ° C, more preferably 90 to 180 ° C, and more preferably 100 to 200, from the viewpoint that the sheet softens in the laminating step of the resin composition sheet and has desired heat resistance. 150 ° C. is more preferable. The softening point is measured by the ring and ball method according to JIS K2207.

  The component (C) may be used alone or in combination of two or more. The content of the component (C) in the resin composition is not particularly limited, but from the viewpoint of maintaining good moisture permeation resistance of the resin composition, when the nonvolatile content in the resin composition is 100% by mass, 80 mass% or less is preferable, 60 mass% or less is more preferable, and 50 mass% or less is further preferable. On the other hand, from the viewpoint of having sufficient adhesiveness, when the nonvolatile content in the resin composition is 100% by mass, it is preferably 5% by mass or more, more preferably 10% by mass or more, and further preferably 15% by mass or more.

  The following resin composition is mentioned as an aspect of the resin composition for closure used as a reference example of the present invention. That is, a polyolefin resin having an acid anhydride group and / or an epoxy group, and a sealing resin composition containing a tackifying resin, preferably a polyolefin resin having an acid anhydride group and an epoxy group An encapsulating resin composition containing a polyolefin-based resin and a tackifying resin is included. The polyolefin resin having an acid anhydride group is not particularly limited as long as it is a resin having an acid anhydride group by acid anhydride modification, and is modified with the (meth) acrylic acid alkyl ester of component (A) and an acid anhydride. The above-mentioned polyolefin resin may be used, or other functional group may be contained by other modification. That is, the "polyolefin resin having an acid anhydride group" has the other characteristics except that the modification with a (meth) acrylic acid alkyl ester is not essential. Followed by an anhydride-modified polyolefin resin. For example, the polyolefin resin may be a copolymer, and specific examples of the copolymer include, for example, ethylene-non-conjugated diene copolymer, ethylene-butene copolymer, ethylene-butene-non-conjugated diene copolymer. Polymer, ethylene-propylene copolymer, ethylene-propylene-non-conjugated diene copolymer, ethylene-propylene-butene copolymer, propylene-butene copolymer, propylene-butene-non-conjugated diene copolymer, isobutylene- Examples thereof include a butene copolymer, an isobutylene-butene-non-conjugated diene copolymer, a styrene-isobutylene copolymer, a styrene-isobutylene-styrene copolymer and the like. The tackifying resin has the same meaning as the tackifying resin as the component (C). The functional group concentration of the acid anhydride group and / or epoxy group of the polyolefin resin having the acid anhydride group and / or epoxy group is preferably 0.05 to 10 mmol / g. The content of the propylene-butene copolymer having an acid anhydride group and / or an epoxy group is preferably 35 to 80% by mass based on 100% by mass of the total nonvolatile content in the resin composition. The sealing resin composition here can be preferably used for sealing an organic EL element. The resin composition for an encapsulant here can be used in the form of an encapsulating sheet, for example, for organic EL encapsulation.

<Curing accelerator>
The resin composition of the present invention (the resin composition containing the components (A) to (C)) and the resin composition of the reference example further contain a curing accelerator from the viewpoint of forming a good crosslinked structure. You may let me. The curing accelerator is not particularly limited, and examples thereof include an amine curing accelerator, a guanidine curing accelerator, an imidazole curing accelerator, and a phosphonium curing accelerator. The curing accelerators may be used alone or in combination of two or more.

  The amine curing accelerator is not particularly limited, but quaternary ammonium salts such as tetramethylammonium bromide and tetrabutylammonium bromide; DBU (1,8-diazabicyclo [5.4.0] undecene-7), DBN (1,5-diazabicyclo [4.3.0] nonene-5), DBU-phenol salt, DBU-octylate, DBU-p-toluenesulfonate, DBU-formate, DBU-phenol novolac resin salt, etc. Diazabicyclo compounds; tertiary amines such as benzyldimethylamine, 2- (dimethylaminomethyl) phenol, 2,4,6-tris (dimethylaminomethyl) phenol and salts thereof, aromatic dimethylurea, aliphatic dimethylurea, Dimethylurea compounds such as aromatic dimethylurea; and the like. These may be used alone or in combination of two or more.

  The guanidine curing accelerator is not particularly limited, but includes dicyandiamide, 1-methylguanidine, 1-ethylguanidine, 1-cyclohexylguanidine, 1-phenylguanidine, 1- (o-tolyl) guanidine, dimethylguanidine, diphenylguanidine. , Trimethylguanidine, tetramethylguanidine, pentamethylguanidine, 1,5,7-triazabicyclo [4.4.0] dec-5-ene, 7-methyl-1,5,7-triazabicyclo [4. 4.0] Deca-5-ene, 1-methyl biguanide, 1-ethyl biguanide, 1-n-butyl biguanide, 1-n-octadecyl biguanide, 1,1-dimethyl biguanide, 1,1-diethyl biguanide, 1- Cyclohexyl biguanide, 1-allyl biguanide, 1-phenyl biguanide , 1- (o-tolyl) biguanide and the like. These may be used alone or in combination of two or more.

  The imidazole-based curing accelerator is not particularly limited, but 1H-imidazole, 2-methyl-imidazole, 2-phenyl-4-methylimidazole, 1-cyanoethyl-2-ethyl-4-methyl-imidazole, 2-phenyl- 4,5-bis (hydroxymethyl) -imidazole, 1-benzyl-2-methylimidazole, 1-benzyl-2-phenylimidazole, 2-ethyl-4-methylimidazole, 2-phenyl-imidazole, 2-dodecyl-imidazole , 2-heptadecyl imidazole, 1,2-dimethyl-imidazole and the like. These may be used alone or in combination of two or more.

  The phosphonium-based curing accelerator is not particularly limited, but includes triphenylphosphine, phosphonium borate compound, tetraphenylphosphonium tetraphenylborate, n-butylphosphonium tetraphenylborate, tetrabutylphosphonium decanoate, (4-methylphenyl). Examples thereof include triphenylphosphonium thiocyanate, tetraphenylphosphonium thiocyanate and butyltriphenylphosphonium thiocyanate. These may be used alone or in combination of two or more.

  The curing accelerator may be used alone or in combination of two or more. The content of the curing accelerator in the resin composition is not particularly limited, but if the nonvolatile content in the resin composition is 100% by mass, it is 5% by mass or less from the viewpoint of preventing a decrease in moisture permeation resistance. It is preferably 1% by mass or less. On the other hand, from the viewpoint of suppressing tack, when the nonvolatile content in the resin composition is 100% by mass, 0.01% by mass or more is preferable, and 0.05% by mass or more is more preferable.

<Hygroscopic metal compound>
The resin composition of the present invention may further contain a hygroscopic metal oxide in order to further improve the moisture permeation resistance. Here, the “hygroscopic metal oxide” means a metal oxide having the ability to absorb water and chemically reacting with the absorbed water to form a hydroxide. Specifically, it is one kind selected from calcium oxide, magnesium oxide, strontium oxide, aluminum oxide, barium oxide, etc., or a mixture or solid solution of two or more kinds. Specific examples of the mixture or solid solution of two or more kinds include calcined dolomite (mixture containing calcium oxide and magnesium oxide), calcined hydrotalcite (solid solution of calcium oxide and aluminum oxide), and the like. To be Among them, calcium oxide, magnesium oxide, and calcined hydrotalcite are preferable, and calcined hydrotalcite is more preferable, from the viewpoint of high hygroscopicity, cost, and stability of raw materials. The calcined hydrotalcite reduces the amount of OH in the chemical structure by calcining natural hydrotalcite (Mg ₆ Al ₂ (OH) ₁₆ CO ₃ .4H ₂ O) and synthetic hydrotalcite (hydrotalcite-like compound). To those that have disappeared. From the viewpoint of improving the transparency of the cured product of the resin composition, calcined hydrotalcite having a BET specific surface area of 65 m ² / g or more is particularly preferable. The BET specific surface area of the calcined hydrotalcite having a BET specific surface area of 65 m ² / g or more is preferably 80 m ² / g or more, and more preferably 100 m ² / g or more. Further, BET specific surface area is preferably from 200m ² / g, more preferably at most 150m ² / g.

  Hygroscopic metal oxides are known as hygroscopic materials in various technical fields, and commercially available products can be used. Specifically, calcium oxide (“Moistop # 10” manufactured by Sankyo Milling Co., Ltd.), magnesium oxide (“Kyowamag MF-150”, “Kyowamag MF-30”, Kyowamag MF-30, “Puremag” manufactured by Tateho Chemical Industry) FNMG ", etc.), lightly burned magnesium oxide (" TATEHOMAG # 500 "," TATEHOMAG # 1000 ", TATEHOMAG # 5000, etc. made by Tateho Chemical Industry Co., Ltd.), calcined dolomite (" KT "manufactured by Yoshizawa Lime Company, etc.), calcined hydro Examples thereof include talcite (“DHT-4A”, DHT-4A-2, DHT-4C, etc. manufactured by Kyowa Chemical Industry Co., Ltd.).

  The hygroscopic metal oxide may be surface-treated with a surface treatment agent. As the surface treatment agent used for the surface treatment, for example, higher fatty acids, alkylsilanes, silane coupling agents and the like can be used, and among them, higher fatty acids and alkylsilanes are preferable. As the surface treatment agent, one kind or two or more kinds can be used.

  Examples of the higher fatty acid include higher fatty acids having 18 or more carbon atoms such as stearic acid, montanic acid, myristic acid, and palmitic acid. Among them, stearic acid is preferable. These may be used alone or in combination of two or more. Examples of the alkylsilanes include methyltrimethoxysilane, ethyltrimethoxysilane, hexyltrimethoxysilane, octyltrimethoxysilane, decyltrimethoxysilane, octadecyltrimethoxysilane, dimethyldimethoxysilane, octyltriethoxysilane, and n-octadecyldimethyl ( 3- (trimethoxysilyl) propyl) ammonium chloride and the like can be mentioned. These may be used alone or in combination of two or more. Examples of the silane coupling agent include 3-glycidyloxypropyltrimethoxysilane, 3-glycidyloxypropyltriethoxysilane, 3-glycidyloxypropyl (dimethoxy) methylsilane and 2- (3,4-epoxycyclohexyl) ethyltrimethoxy. Epoxy-based silane coupling agents such as silane; mercapto-based silane coupling agents such as 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, 3-mercaptopropylmethyldimethoxysilane and 11-mercaptoundecyltrimethoxysilane 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-aminopropyldimethoxymethylsilane, N-phenyl-3-aminopropyltrisilane Amino-based silane cups such as toxysilane, N-methylaminopropyltrimethoxysilane, N- (2-aminoethyl) -3-aminopropyltrimethoxysilane and N- (2-aminoethyl) -3-aminopropyldimethoxymethylsilane Ring agent; ureido silane coupling agent such as 3-ureidopropyltriethoxysilane, vinyl silane coupling agent such as vinyltrimethoxysilane, vinyltriethoxysilane and vinylmethyldiethoxysilane; p-styryltrimethoxysilane, etc. Styryl-based silane coupling agent; acrylate-based silane coupling agent such as 3-acryloxypropyltrimethoxysilane and 3-methacryloxypropyltrimethoxysilane; 3-isocyanatopropyltrimetho Isocyanate-based silane coupling agents such as silane, sulfide-based silane coupling agents such as bis (triethoxysilylpropyl) disulfide, bis (triethoxysilylpropyl) tetrasulfide; phenyltrimethoxysilane, methacryloxypropyltrimethoxysilane, imidazole Examples thereof include silane and triazine silane. These may be used alone or in combination of two or more.

  The surface treatment of the hygroscopic metal oxide is performed, for example, by stirring and dispersing the untreated hygroscopic metal oxide at room temperature while adding and spraying the surface treatment agent and stirring for 5 to 60 minutes. You can As the mixer, a known mixer can be used, and examples thereof include a blender such as a V blender, a ribbon blender, and a bubble cone blender, a mixer such as a Henschel mixer and a concrete mixer, a ball mill, a cutter mill, and the like. In addition, when pulverizing the hygroscopic material with a ball mill or the like, a method of mixing the above-mentioned higher fatty acid, alkylsilanes or silane coupling agent and surface-treating is also possible. The treatment amount of the surface treatment agent varies depending on the type of hygroscopic metal oxide or the type of surface treatment agent, but is preferably 1 to 10% by mass with respect to the hygroscopic metal oxide.

  The hygroscopic metal oxide may be used alone or in combination of two or more kinds. When the resin composition of the present invention contains a hygroscopic metal compound, the content is not particularly limited, but from the viewpoint of preventing the strength of the cured product from decreasing and becoming brittle, the resin composition It is preferably 50% by mass or less, more preferably 40% by mass or less, and further preferably 30% by mass or less, relative to 100% by mass of the nonvolatile content in the medium. Further, from the viewpoint of sufficiently obtaining the effect of adding the hygroscopic metal oxide, 1% by mass or more is preferable, 5% by mass or more is more preferable, and 10% by mass is 10% by mass with respect to 100% by mass of the nonvolatile content in the resin composition. % Or more is more preferable.

<Plasticizer>
The resin composition of the present invention can improve the flexibility and moldability of the resin composition by further containing a plasticizer. The plasticizer is not particularly limited, but a liquid material at room temperature is preferably used. Specific examples of the plasticizer include paraffin-based process oil, naphthene-based process oil, liquid paraffin, polyethylene wax, polypropylene wax, mineral oil such as vaseline, castor oil, cottonseed oil, rapeseed oil, soybean oil, palm oil, coconut oil, olive oil. And other liquid oils such as vegetable oils, liquid polybutene, hydrogenated liquid polybutene, liquid polybutadiene, hydrogenated liquid polybutadiene, and the like. As the plasticizer used in the present invention, liquid polyα-olefins are preferable, and liquid polybutadiene is particularly preferable. Further, as the liquid poly-α-olefin, one having a low molecular weight is preferable from the viewpoint of adhesiveness, and one having a weight average molecular weight of 500 to 5,000, more preferably 1,000 to 3,000 is preferable. These plasticizers may be used alone or in combination of two or more. The term "liquid" as used herein means the state of the plasticizer at room temperature (25 ° C). When the resin composition of the present invention contains a plasticizer, when the nonvolatile content in the resin composition is 100% by mass, from the viewpoint of not adversely affecting the organic EL device, the content is within the range of 50% by mass or less. used.

<Other additives>
The resin composition of the present invention may optionally contain various additives other than the above-mentioned components to the extent that the effects of the present invention are not impaired. Examples of such additives include silica, barium sulfate, talc, clay, mica powder, aluminum hydroxide, magnesium hydroxide, calcium carbonate, magnesium carbonate, boron nitride, aluminum borate, barium titanate, and strontium titanate. , Calcium titanate, magnesium titanate, bismuth titanate, titanium oxide, barium zirconate, calcium zirconate and other inorganic fillers; rubber particles, silicone powder, nylon powder, fluororesin powder and other organic fillers; Orben, Benton And the like; silicone-based, fluorine-based, polymer-based defoaming agents or leveling agents; adhesion imparting agents such as triazole compounds, thiazole compounds, triazine compounds, and porphyrin compounds; and the like.

  The method for preparing the resin composition of the present invention is not particularly limited, and examples thereof include a method of adding a solvent and the like to the compounding ingredients and mixing the ingredients using a kneading roller or a rotary mixer.

  The resin composition of the present invention is used for encapsulating electronic parts such as semiconductors, solar cells, high-intensity LEDs, LCDs and EL elements. Particularly, it is preferably used for sealing the organic EL element, and specifically, applied to the upper part and / or the periphery (side part) of the light emitting part of the organic EL element to protect the light emitting part of the organic EL element from the outside. Can be used for.

  When the resin composition of the present invention is applied to an organic EL device, the transparency of the sealing layer formed of the resin composition can be measured by a spectrophotometer. The higher the transparency, the better in terms of improving the luminous efficiency of the organic EL element. Specifically, in the sealing layer having a thickness of 30 μm, the parallel line transmittance at 450 nm is preferably 80% or more, more preferably 82% or more, further preferably 84% or more, and even more preferably 86% or more, 88% or more is particularly preferable, and 90% or more is particularly preferable.

  The resin composition of the present invention is an ester bond formed by the reaction between the acid anhydride group of the polyolefin resin (A) modified with (meth) acrylic acid alkyl ester and the acid anhydride and the epoxy group of the epoxy resin (B). Are preferably formed. By forming the crosslinked structure in this way, it is possible to form a sealing layer having excellent adhesive and heat resistance, moisture resistance and the like. The ester bond can be formed by, for example, adding an organic solvent to the resin composition to prepare a varnish-shaped resin composition, and heating and drying the varnish. The organic solvent can be dried by blowing hot air or the like.

  Examples of the organic solvent include ketones such as acetone, methyl ethyl ketone (hereinafter also abbreviated as “MEK”) and cyclohexanone; acetic acid esters such as ethyl acetate, butyl acetate, cellosolve acetate, propylene glycol monomethyl ether acetate and carbitol acetate. Carbitols such as cellosolve and butyl carbitol; aromatic hydrocarbons such as toluene and xylene; dimethylformamide, dimethylacetamide, N-methylpyrrolidone and the like; aromatic mixed solvents such as solvent naphtha and the like. Examples of the aromatic mixed solvent include "Swazol" (manufactured by Maruzen Petroleum Co., Ltd.) and "Ipsol" (manufactured by Idemitsu Kosan Co., Ltd.). The organic solvent may be used alone or in combination of two or more.

  The drying condition is not particularly limited, but 50 to 100 ° C. and 1 to 60 minutes are preferable. By setting the temperature to 50 ° C. or higher, the amount of solvent remaining in the resin composition layer can be easily reduced.

<Sealing sheet>
The sealing sheet of the present invention is a sealing sheet in which an adhesive layer is formed on a support, and the adhesive layer is formed of the resin composition of the present invention. The adhesive layer is formed, for example, by preparing a varnish in which the resin composition of the present invention is dissolved in an organic solvent, applying the varnish on a support, and drying the varnish. The organic solvent can be dried by blowing hot air or the like, and an ester bond formed by the reaction between the acid anhydride group of the component (A) and the epoxy group of the component (B) in the resin composition is formed during this drying. Is preferred. By forming such a crosslinked structure by an ester bond, the resin composition becomes a pressure-sensitive adhesive resin composition having excellent resistance to moisture and heat resistance, moisture resistance and the like. Specific examples of the organic solvent include those similar to the above organic solvent, and the drying conditions can be the same as the above drying conditions.

  The thickness of the adhesive layer in the encapsulating sheet is preferably 3 μm to 200 μm, more preferably 5 μm to 100 μm, still more preferably 5 μm to 50 μm.

As will be described later, when the final sealing structure of interest is a structure in which a sealing base material is laminated on an adhesive layer (resin composition layer), the part where moisture can penetrate is on the adhesive layer side. Since only the parts are provided, by reducing the thickness of the adhesive layer, the area of the side parts in contact with the outside air becomes smaller. Therefore, it is desirable to reduce the thickness of the adhesive layer in order to block moisture. However, if the layer thickness of the adhesive layer is too small, the element may be damaged when the sealing base material is attached, and the workability in attaching the sealing base material tends to decrease. In addition, setting the thickness of the adhesive layer within the above-mentioned preferred range ensures uniformity of the thickness of the adhesive layer after transferring the adhesive layer to a sealing target (for example, a substrate on which an element such as an organic EL element is formed). It is also effective in keeping.
As the support used for the encapsulating sheet, a support having moisture resistance is preferable. Examples of the moisture-proof support include moisture-proof plastic films and metal foils such as copper foil and aluminum foil. Examples of the moisture-proof plastic film include plastic films having a surface deposited with an inorganic substance such as silicon oxide (silica), silicon nitride, SiCN, and amorphous silicon. Here, examples of the plastic film on the surface of which an inorganic substance is vapor-deposited include polyolefin (eg, polyethylene, polypropylene, polyvinyl chloride, etc.), polyester (eg, polyethylene terephthalate (hereinafter sometimes abbreviated as “PET”).) , Polyethylene naphthalate, etc.), polycarbonate, polyimide, and other plastic films are preferable, and PET films are particularly preferable. Examples of commercially available moisture-proof plastic films include Tech Barrier HX, AX, LX, L series (manufactured by Mitsubishi Plastics Co., Ltd.) and a more moisture-proof effect than the Tech Barrier HX, AX, LX, L series. For example, an enhanced X-BARRIER (manufactured by Mitsubishi Plastics, Inc.) and the like can be mentioned. Further, as the moisture-proof support, a support having a multilayer structure of two or more layers, for example, a support obtained by laminating the above plastic film and the above metal foil with an adhesive can be used. This is inexpensive and advantageous from the viewpoint of handleability. As the support of the resin composition sheet, a support having no moisture-proof property (for example, a single plastic film having no inorganic substance deposited on the surface) can also be used.

  Although the thickness of the support is not particularly limited, it is preferably 10 to 150 μm, more preferably 20 to 100 μm from the viewpoint of handleability of the encapsulating sheet.

  In addition, the encapsulating sheet of the present invention has an adhesive layer surface of before the actual use for forming the encapsulation structure in order to prevent adhesion of dust or the like to the surface of the adhesive layer (resin composition layer) and scratches. It is preferably protected by a protective film, and as the protective film, the plastic films exemplified above as the support can be used. The protective film may be subjected to a matte treatment, a corona treatment, or a release treatment in advance. Specific examples of the release agent include a fluorine-based release agent, a silicone-based release agent, and an alkyd resin-based release agent. The release agent may be a mixture of different types. The thickness of the protective film is not particularly limited, but is preferably 1 to 40 μm, more preferably 10 to 30 μm.

  The encapsulating sheet of the present invention is used by being laminated on an object to be encapsulated. As used herein, the term “laminate” refers to a state in which the sealing object is covered with the encapsulating sheet with the support, and the adhesive layer (resin composition layer) in which the encapsulating object is transferred from the encapsulating sheet. ) Is included. When the encapsulating sheet is a substrate having a non-moisture proof property (for example, a single plastic film having no inorganic substance deposited on the above surface), the encapsulating sheet is laminated on the object to be encapsulated. After that, it is preferable that the support is peeled off (that is, the adhesive layer (resin composition layer) is transferred), and then a sealing substrate is separately laminated on the adhesive layer. In particular, when the sealing target is a substrate on which an organic EL element is formed (hereinafter, also referred to as “organic EL element formation substrate”), a mode in which such a sealing base material is laminated is preferable. The "sealing base material" as used in the present invention means that the moisture-proof support used for the sealing sheet is used alone without forming an adhesive layer (resin composition layer) on the support. Is. Further, a glass plate, a metal plate, a steel plate or the like which is not suitable for use as a support for a sealing sheet and which has no flexibility, but has a high moisture resistance is also included in the “sealing substrate”.

<Organic EL device>
The organic EL device of the present invention is an organic EL device in which an organic EL element is sealed with a sealing layer, and the sealing layer is formed of the resin composition of the present application. For example, the organic EL device of the present invention is obtained by laminating the encapsulating sheet of the present invention on a substrate having an organic EL element. When the encapsulating sheet is protected by a protective film, the encapsulating sheet is peeled off, and then the encapsulating sheet is attached so that the adhesive layer (resin composition layer) directly contacts the substrate having the organic EL element. Laminate on a substrate having. The laminating method may be a batch method or a continuous method using rolls.

  When the support of the sealing sheet is a moisture-proof support, after the sealing sheet is laminated on the substrate having the organic EL element, the support is not peeled off and the organic EL element is sealed as it is. The process is complete. If heat curing is required after the sealing step, heat curing is performed. By doing so, an organic EL device in which the organic EL element is sealed by the sealing layer formed of the resin composition of the present invention is obtained.

  Generally, the sealing material for an organic EL element needs to be dried before the sealing operation to remove the absorbed water, and the operation is complicated, but a support having moisture resistance is used. Since the encapsulating sheet of the present invention using is highly moisture-permeable, it has a low water absorption rate during storage and device manufacturing operations. Further, the damage given to the organic EL element during the sealing work is also remarkably reduced.

When a sealing sheet using a support having no moisture resistance is used, after the sealing sheet is laminated on a substrate having an organic EL element, the support is peeled off to expose an adhesive layer (resin composition layer) The sealing process of the organic EL element is completed by pressure-bonding the sealing substrate. Two or more sealing base materials may be used in combination from the viewpoint of increasing the moisture-proof effect. The thickness of the sealing substrate is preferably 5 mm or less, more preferably 1 mm or less, and even more preferably 100 μm or less, from the viewpoint of making the organic EL device itself thin and light. From the viewpoint of preventing water permeation, it is preferably 5 μm or more, more preferably 10 μm or more, still more preferably 20 μm or more. The pressure at the time of pressure-bonding the sealing substrate is preferably about 0.3 to 10 kgf / cm ² , and when pressure-bonding under heating, 25 ° C to 130 ° C is preferable.

  When the substrate having the organic EL element is a transparent substrate on which the organic EL element is formed, if the transparent substrate side is used as the display surface of the display or the light emitting surface of the lighting fixture, It is not always necessary to use a transparent material, and a metal plate, a metal foil, an opaque plastic film or plate, or the like may be used. On the other hand, when the substrate having the organic EL element is formed on the substrate made of a material having opacity or low transparency, the sealing substrate side is used as the display surface of the display or the light emitting surface of the lighting fixture. Therefore, a transparent plastic film, a glass plate, a transparent plastic plate, or the like is used as the sealing substrate.

  Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited to these examples. In the following description, "part" means "part by mass" and "%" means "% by mass" unless otherwise specified.

First, materials used in Examples and Comparative Examples will be described.
(A) Modified polyolefin resin T-YP429 (manufactured by Seikou PMC): 2-ethylhexyl acrylate and maleic anhydride modified ethylene-methyl methacrylate copolymer (ethylene unit / methyl methacrylate unit = 68% by mass / 32% by mass) , Concentration of maleic anhydride group 0.46 mmol / g, number average molecular weight of modified copolymer 2300, number average molecular weight of graft chain 386, content of 2-ethylhexyl acrylate unit in graft chain 50% by mass)
-T-YP430 (manufactured by Seikou PMC): 2-ethylhexyl acrylate and maleic anhydride-modified ethylene-methyl methacrylate copolymer (ethylene unit / methyl methacrylate unit = 68% by mass / 32% by mass, maleic anhydride group concentration: 1) 18 mmol / g, modified copolymer number average molecular weight 4500, graft chain number average molecular weight 386, graft chain 2-ethylhexyl acrylate unit content 50% by mass)
T-YP953 (manufactured by Seikou PMC Co., Ltd.): 2-ethylhexyl acrylate and maleic anhydride-modified propylene-butene copolymer 80 mass% and 2-ethylhexyl acrylate and maleic anhydride-modified propylene-ethylene copolymer 20 mass% Mixture (concentration of maleic anhydride group 0.44 mmol / g, number average molecular weight of modified copolymer 33200, number average molecular weight of graft chain 856, content of 2-ethylhexyl acrylate unit in graft chain 50% by mass)
T-YP955 (manufactured by Seikou PMC): 67% by mass of 2-ethylhexyl acrylate and maleic anhydride-modified propylene-butene copolymer and 33% by mass of 2-ethylhexyl acrylate and maleic anhydride-modified propylene-ethylene copolymer Mixture (concentration of maleic anhydride group 0.94 mmol / g, number average molecular weight of modified copolymer 22700, number average molecular weight of graft chain 620, content of 2-ethylhexyl acrylate unit in graft chain 50% by mass)
T-YP956 (manufactured by Seikou PMC): 2-ethylhexyl acrylate and maleic anhydride modified ethylene-propylene-butene random copolymer (maleic anhydride group concentration 1.80 mmol / g, number average molecular weight of modified copolymer) 3000, the number average molecular weight of the graft chain 423, the content of 2-ethylhexyl acrylate units in the graft chain is 50% by mass)
-T-YP279 (manufactured by Seikou PMC): 2-ethylhexyl acrylate and maleic anhydride-modified propylene-butene random copolymer (propylene unit / butene unit = 64% by mass / 36% by mass, maleic anhydride group concentration: 0. 464 mmol / g, number average molecular weight 35,000 number average molecular weight of graft chain 644, content of 2-ethylhexyl acrylate unit in graft chain 50% by mass)
-T-YP312 (manufactured by Seikou PMC): 2-ethylhexyl acrylate and maleic anhydride-modified propylene-butene copolymer (propylene unit / butene unit = 71 mass% / 29 mass%, maleic anhydride group concentration 0.464 mmol) / G, number average molecular weight 60900 of modified copolymer, number average molecular weight 611 of graft chain, content of 2-ethylhexyl acrylate unit in graft chain 50% by mass) (B) epoxy resin-828EL (manufactured by Mitsubishi Chemical Corporation) ): Bisphenol A type epoxy resin, epoxy equivalent 190 g / eq
-EPICLON EXA4850-1000 (manufactured by DIC): Epoxy resin containing polypropylene glycol skeleton, epoxy equivalent 350 g / eq
-T-YP431 (manufactured by Seikou PMC): Glycidyl methacrylate modified ethylene-methyl methacrylate copolymer (epoxy group concentration 0.64 mmol / g, number average molecular weight 2400)
-T-YP432 (manufactured by Seikou PMC): Glycidyl methacrylate modified ethylene-methyl methacrylate copolymer (epoxy group concentration 1.63 mmol / g, number average molecular weight 3100)
-BONDFAST BF-7M (Sumitomo Chemical Co., Ltd.): ethylene-glycidyl methacrylate copolymer (epoxy group concentration 0.4 mmol / g)
-T-YP252 (manufactured by Seikou PMC): a mixture of 80% glycidyl methacrylate-modified propylene-blundum copolymer and 20% glycidyl methacrylate-modified propylene-ethylene random copolymer (epoxy group concentration 0.64 mmol / g, number average molecular weight) 34000)
T-YP313 (manufactured by Seikou PMC): Glycidyl methacrylate modified propylene-butene random copolymer (propylene unit / butene unit = 71 mass% / 29 mass%, epoxy group concentration 0.638 mmol / g, number average molecular weight 155000)
T-YP276 (manufactured by Seikou PMC): Glycidyl methacrylate modified propylene-butene random copolymer (propylene unit / butene unit = 64% by mass / 29% by mass, epoxy group concentration 0.638 mmol / g, number average molecular weight 57,000)
(C) Tackifying resin-TFS13-030 (manufactured by Arakawa Chemical Co., Ltd.): cyclohexane ring-containing saturated hydrocarbon resin, softening point 125 ° C.
(D) Curing accelerator-Anionic polymerization curing accelerator: 2,4,6-tris (dimethylaminomethyl) phenol (hereinafter abbreviated as "TAP")
(F) Hygroscopic metal oxide-calcined hydrotalcite (Kyowa Chemical Industry's "DHT-4C")
(Other materials)
ACRYFT CM5022 (Sumitomo Chemical Co., Ltd.): ethylene-methyl methacrylate copolymer L-MODU S400 (Idemitsu Kosan Co., Ltd.): polypropylene resin, average molecular weight 45000
SIBSTAR-102T (Kaneka): Styrene-isobutylene-styrene block copolymer, average molecular weight 100,000
-Swazol # 1000 (Maruzen Oil Co., Ltd.): Aromatic mixed solvent-Toluene

[Measurement method / Evaluation method]
Various measuring methods and evaluation methods will be described.

<Evaluation of adhesion wet heat resistance>
Using a batch type vacuum laminator (manufactured by Nichigo Morton Co., Morton-724) for sealing sheet (length 50 mm, width 20 mm) using a PET film as a support, aluminum foil (length 100 mm, width 20 mm, It was laminated to a thickness of 50 μm, manufactured by Sumikari Aluminum Foil Co., product number SA50). Lamination was performed under the conditions of a temperature of 80 ° C., a time of 300 seconds and a pressure of 0.3 MPa. Then, the PET film was peeled off, and a glass plate (length: 76 mm, width: 26 mm, thickness: 1.2 mm, micro slide glass) was laminated on the exposed resin composition layer under the same conditions as above. With respect to the obtained laminate, the adhesive strength was measured when peeled in a 90 degree direction with respect to the length direction of the aluminum foil at a pulling speed of 50 mm / min (initial adhesive strength). Further, the test piece prepared in the same manner as above was held under conditions of 85 ° C. and 85% RH for 24 hours, and then the adhesive strength was measured by the above method (adhesive strength after high temperature and high humidity environment test).

<Evaluation of workability>
When the resin composition varnish is applied uniformly on the release-treated surface of a PET film (thickness 30 μm) treated with a silicone-based release agent with a die coater, the fluidity of the varnish is maintained (stable with time). Property) was evaluated as ◯ when stable coating was possible, and as × when stable coating was impossible due to thickening or the like.

<Evaluation of moisture resistance>
The resin composition layer (thickness: 45 μm) of the resin composition sheets produced in Examples and Comparative Examples was peeled from the support (PET film) to the adhesive layer, at a temperature of 40 ° C. and a humidity of 40 ° C. by a method according to JIS Z0208. The water vapor permeation amount was measured under the conditions of 90% RH and 24 hours to obtain the water vapor permeation amount per 1 m 2. When the amount of water vapor permeation was 100 g / m ² · 24 hr or more, the moisture permeation resistance was judged to be “poor”, and when less than 100 g / m ² · 24 hr, it was evaluated as “good”.

  A sealing sheet was obtained by the method described below. Unless otherwise specified, the value of each part is a value converted into a nonvolatile content.

<Example 1>
2-ethylhexyl acrylate and maleic anhydride-modified ethylene-methyl methacrylate copolymer (T-YP429, 20% toluene solution) in 37 parts, and cyclohexane ring-containing saturated hydrocarbon resin refined product (TFS13-030, 60% toluene solution) 35 parts were mixed and mixed with a high-speed rotary mixer to obtain a uniform mixed solution. To this mixed solution, 27 parts of glycidyl methacrylate-modified ethylene-methymethacrylate copolymer (T-YP431, 20% toluene solution) and 0.5 part of anionic polymerization type curing accelerator (TAP) were uniformly mixed with a high-speed rotating mixer. And got a varnish. The resulting varnish was applied evenly on a release-treated surface of a PET film (thickness 30 μm) treated with a silicone-based release agent with a die coater, and cured by heating at 130 ° C. for 60 minutes to obtain a resin. A sealing sheet having a composition layer thickness of 20 μm was obtained.

<Example 2>
2-ethylhexyl acrylate and maleic anhydride-modified ethylene-methyl methacrylate copolymer (T-YP430, 20% toluene solution) in 37 parts, and cyclohexane ring-containing saturated hydrocarbon resin purified product (TFS13-030, 60% toluene solution) 35 parts were mixed and mixed with a high-speed rotary mixer to obtain a uniform mixed solution. To this mixed solution, 27 parts of glycidyl methacrylate modified ethylene-methyl methacrylate copolymer (T-YP432, 20% toluene solution) and 0.5 part of anionic polymerization type curing accelerator (TAP) were uniformly mixed with a high speed rotation mixer. And got a varnish. The resulting varnish was applied evenly on a release-treated surface of a PET film (thickness 30 μm) treated with a silicone-based release agent with a die coater, and cured by heating at 130 ° C. for 60 minutes to obtain a resin. A sealing sheet having a composition layer thickness of 20 μm was obtained.

<Example 3>
2-Ethylhexyl acrylate and maleic anhydride-modified ethylene-methyl methacrylate copolymer (T-YP429, 20% swathol solution) in 30 parts, cyclohexane ring-containing saturated hydrocarbon resin purified product (TFS13-030, 60% toluene solution) 35 parts were mixed and mixed with a high-speed rotary mixer to obtain a uniform mixed solution. To this mixed solution, 34 parts of an ethylene-glycidyl methacrylate copolymer (BONDFAST BF-7M, 20% swathol solution) and 0.5 part of an anionic polymerization type curing accelerator (TAP) were uniformly mixed with a high speed rotation mixer, I got a varnish. The resulting varnish was applied evenly on a release-treated surface of a PET film (thickness 30 μm) treated with a silicone-based release agent with a die coater, and cured by heating at 130 ° C. for 60 minutes to obtain a resin. A sealing sheet having a composition layer thickness of 20 μm was obtained.

<Example 4>
Mixture of 2-ethylhexyl acrylate and maleic anhydride modified ethylene-propylene copolymer and 2-ethylhexyl acrylate and maleic anhydride modified propylene-butene copolymer (T-YP953, 30% methylcyclohexane + butyl acetate solution) 37 36 parts of a cyclohexane ring-containing saturated hydrocarbon resin refined product (TFS13-030, 60% toluene solution) was mixed and mixed with a high-speed rotary mixer to obtain a uniform mixed solution. 26 parts of a mixture (T-YP252, 30% methylcyclohexane + butyl acetate solution) of a glycidyl methacrylate-modified ethylene-propylene copolymer and a glycidyl methacrylate-modified propylene-butene copolymer was added to this mixed solution, and an anionic polymerization type curing accelerator ( 0.5 parts of TAP) was uniformly mixed with a high-speed rotary mixer to obtain a varnish. The resulting varnish was applied evenly on a release-treated surface of a PET film (thickness 30 μm) treated with a silicone-based release agent with a die coater, and cured by heating at 130 ° C. for 60 minutes to obtain a resin. A sealing sheet having a composition layer thickness of 20 μm was obtained.

<Example 5>
Mixture of 2-ethylhexyl acrylate and maleic anhydride modified ethylene-propylene copolymer and 2-ethylhexyl acrylate and maleic anhydride modified propylene-butene copolymer (T-YP955, 30% methylcyclohexane + butyl acetate solution) 25 36 parts of a cyclohexane ring-containing saturated hydrocarbon resin refined product (TFS13-030, 60% toluene solution) was mixed and mixed with a high-speed rotary mixer to obtain a uniform mixed solution. 38 parts of a mixture (T-YP252, 30% methylcyclohexane + butyl acetate solution) of a glycidyl methacrylate-modified ethylene-propylene copolymer and a glycidyl methacrylate-modified propylene-butene copolymer was added to this mixed solution, and an anionic polymerization type curing accelerator ( 0.5 parts of TAP) was uniformly mixed with a high-speed rotary mixer to obtain a varnish. The resulting varnish was applied evenly on a release-treated surface of a PET film (thickness 30 μm) treated with a silicone-based release agent with a die coater, and cured by heating at 130 ° C. for 60 minutes to obtain a resin. A sealing sheet having a composition layer thickness of 20 μm was obtained.

<Example 6>
To 16 parts of 2-ethylhexyl acrylate and maleic anhydride-modified ethylene-propylene-butene random copolymer (T-YP956, 50% methylcyclohexane + butyl acetate solution), a cyclohexane ring-containing saturated hydrocarbon resin refined product (TFS13-030) was added. , 60% toluene solution) and mixed with a high-speed rotary mixer to obtain a uniform mixed solution. 47 parts of a mixture (T-YP252, 30% methylcyclohexane + butyl acetate solution) of a glycidyl methacrylate-modified ethylene-propylene copolymer and a glycidyl methacrylate-modified propylene-butene copolymer was added to this mixed solution, and an anionic polymerization type curing accelerator ( 0.5 parts of TAP) was uniformly mixed with a high-speed rotary mixer to obtain a varnish. The resulting varnish was applied evenly on a release-treated surface of a PET film (thickness 30 μm) treated with a silicone-based release agent with a die coater, and cured by heating at 130 ° C. for 60 minutes to obtain a resin. A sealing sheet having a composition layer thickness of 20 μm was obtained.

<Example 7>
2-Ethylhexyl acrylate and maleic anhydride-modified propylene-butene copolymer (T-YP279, 40% swathol solution) 28 parts, cyclohexane ring-containing saturated hydrocarbon resin purified product (TFS13-030, 60% toluene solution) 50 The parts were mixed and mixed with a high-speed rotary mixer to obtain a uniform mixed solution. 21 parts of glycidyl methacrylate modified propylene-butene copolymer (T-YP276, 40% swazole solution) and 0.5 part of anionic polymerization type curing accelerator (TAP) were uniformly mixed with this mixed solution with a high-speed rotating mixer. , Got the varnish. The resulting varnish was applied evenly on a release-treated surface of a PET film (thickness 30 μm) treated with a silicone-based release agent with a die coater, and cured by heating at 130 ° C. for 60 minutes to obtain a resin. A sealing sheet having a composition layer thickness of 20 μm was obtained.

<Example 8>
To 35 parts of 2-ethylhexyl acrylate and maleic anhydride-modified propylene-butene copolymer (T-YP279, 40% swazole solution), cyclohexane ring-containing saturated hydrocarbon resin refined product (TFS13-030, 60% toluene solution) 50 The parts were mixed and mixed with a high-speed rotary mixer to obtain a uniform mixed solution. To this mixed solution, 2 parts of bisphenol A type epoxy resin (828EL) and 0.5 part of an anionic polymerization type curing accelerator (TAP) were uniformly mixed with a high speed rotating mixer to obtain a varnish. The resulting varnish was applied evenly on a release-treated surface of a PET film (thickness 30 μm) treated with a silicone-based release agent with a die coater, and cured by heating at 130 ° C. for 60 minutes to obtain a resin. A sealing sheet having a composition layer thickness of 20 μm was obtained.

<Example 9>
To 35 parts of 2-ethylhexyl acrylate and maleic anhydride-modified propylene-butene copolymer (T-YP279, 40% swazole solution), cyclohexane ring-containing saturated hydrocarbon resin refined product (TFS13-030, 60% toluene solution) 50 The parts were mixed and mixed with a high-speed rotary mixer to obtain a uniform mixed solution. To this mixed solution, 2 parts of a polypropylene glycol skeleton-containing epoxy resin (EPICLON EXA4850-1000) and 0.5 part of an anionic polymerization type curing accelerator (TAP) were uniformly mixed with a high-speed rotation mixer to obtain a varnish. The resulting varnish was applied evenly on a release-treated surface of a PET film (thickness 30 μm) treated with a silicone-based release agent with a die coater, and cured by heating at 130 ° C. for 60 minutes to obtain a resin. A sealing sheet having a composition layer thickness of 20 μm was obtained.

<Example 10>
20 parts of 2-ethylhexyl acrylate and maleic anhydride-modified propylene-butene copolymer (T-YP279, 40% swathol solution) and 14 parts of calcined hydrotalcite were mixed and kneaded with a three-roll mill, and then saturated with a cyclohexane ring. 50 parts of a hydrocarbon resin refined product (TFS13-030, 60% toluene solution) was mixed with a high-speed rotary mixer to obtain a uniform mixed solution. To this mixed solution, 14 parts of a glycidyl methacrylate-modified propylene-butene copolymer (T-YP276, 40% swazol solution) and 0.5 part of an anionic polymerization type curing accelerator (TAP) were uniformly mixed with a high-speed rotating mixer. , Got the varnish. The resulting varnish was applied evenly on a release-treated surface of a PET film (thickness 30 μm) treated with a silicone-based release agent with a die coater, and cured by heating at 130 ° C. for 60 minutes to obtain a resin. A sealing sheet having a composition layer thickness of 20 μm was obtained.

<Example 11>
To 28 parts of 2-ethylhexyl acrylate and maleic anhydride modified propylene-butene copolymer (T-YP312, 40% swazole solution), cyclohexane ring-containing saturated hydrocarbon resin purified product (TFS13-030, 60% toluene solution) 50 parts were mixed and mixed with a high-speed rotary mixer to obtain a uniform mixed solution. 21 parts of a glycidyl methacrylate modified propylene-butene copolymer (T-YP313, 40% swazol solution) and 0.5 part of an anionic polymerization type curing accelerator (TAP) were uniformly mixed with this mixed solution with a high-speed rotating mixer. , Got the varnish. The resulting varnish was applied evenly on a release-treated surface of a PET film (thickness 30 μm) treated with a silicone-based release agent with a die coater, and cured by heating at 130 ° C. for 60 minutes to obtain a resin. A sealing sheet having a composition layer thickness of 20 μm was obtained.

<Comparative Example 1>
50 parts of polypropylene resin (L-MODU S400, 45% swallow solution) and 50 parts of cyclohexane ring-containing saturated hydrocarbon resin refined product (TFS13-030, 60% toluene solution) are mixed and mixed by a high-speed rotary mixer to uniformly mix. A solution was obtained. 0.5 part of an anionic polymerization type curing accelerator (TAP) was uniformly mixed with this mixed solution with a high speed rotation mixer to obtain a varnish. The resulting varnish was applied evenly on a release-treated surface of a PET film (thickness 30 μm) treated with a silicone-based release agent with a die coater, and cured by heating at 130 ° C. for 60 minutes to obtain a resin. A sealing sheet having a composition layer thickness of 20 μm was obtained.

<Comparative example 2>
A styrene-isobutylene-styrene block copolymer (SIBSTAR-102T, 45% swathol solution) (50 parts) and a cyclohexane ring-containing saturated hydrocarbon resin refined product (TFS13-030, 60% toluene solution) (50 parts) were mixed, and a high speed rotating mixer was used. To obtain a uniform mixed solution. 0.5 part of an anionic polymerization type curing accelerator (TAP) was uniformly mixed with this mixed solution with a high speed rotation mixer to obtain a varnish. The resulting varnish was applied evenly on a release-treated surface of a PET film (thickness 30 μm) treated with a silicone-based release agent with a die coater, and cured by heating at 130 ° C. for 60 minutes to obtain a resin. A resin composition sheet having a composition layer thickness of 20 μm was obtained.

<Comparative example 3>
64 parts of a polyethylene resin (ACRYFT CM5022, 20% toluene solution) and 35 parts of a cyclohexane ring-containing saturated hydrocarbon resin refined product (TFS13-030, 60% toluene solution) are mixed and mixed with a high-speed rotary mixer to form a uniform mixed solution. Obtained. 0.5 part of an anionic polymerization type curing accelerator (TAP) was uniformly mixed with this mixed solution with a high speed rotation mixer to obtain a varnish. The resulting varnish was applied evenly on a release-treated surface of a PET film (thickness 30 μm) treated with a silicone-based release agent with a die coater, and cured by heating at 130 ° C. for 60 minutes to obtain a resin. A sealing sheet having a composition layer thickness of 20 μm was obtained.

  Table 1 shows the evaluation results of the examples and comparative examples.

  From the results of the examples, it can be seen that the encapsulating resin composition of the present invention has good adhesion wet heat resistance and moisture permeability resistance. The workability was also good, and stable coating was possible.

  INDUSTRIAL APPLICABILITY The resin composition of the present invention has good adhesiveness and adhesion wet heat resistance, and is suitably used for sealing electronic parts such as semiconductors, solar cells, high-brightness LEDs, LCDs and EL elements, and particularly organic EL elements. It is preferably used for sealing.

Claims (14)

(A) contains a (meth) acrylic acid alkyl ester and a polyolefin resin modified with an acid anhydride, (B) an epoxy resin, and (C) a tackifying resin, and the (B) epoxy resin is an epoxy-modified polyolefin system. sealing resin composition, wherein the resin der Rukoto.   (A) A polyolefin-based resin modified with an alkyl (meth) acrylate and an acid anhydride is bonded to a graft polymer containing a (meth) acrylic acid alkyl ester unit and an acid anhydride unit in the main chain of the polyolefin-based resin. The encapsulating resin composition according to claim 1, wherein the encapsulating resin composition is a graft modified product, and the number average molecular weight of the graft polymer is 100 or more.   The number of carbon atoms of the alkyl group of the (meth) acrylic acid alkyl ester in the polyolefin resin modified with the (A) (meth) acrylic acid alkyl ester and the acid anhydride is 1 to 18. 3. The encapsulating resin composition of.   The concentration of the acid anhydride group in the polyolefin resin modified with the (A) (meth) acrylic acid alkyl ester and the acid anhydride is 0.05 to 10 mmol / g. The encapsulating resin composition described. Epoxy group concentration in the epoxy-modified polyolefin resin is 0.05~10mmol / g, the encapsulating resin composition according to claim 1. When the total content of the (A) alkyl ester of (meth) acrylic acid, the polyolefin resin modified with an acid anhydride, and the (B) epoxy resin is 100% by mass of the nonvolatile content in the resin composition, 5 it is 80 wt%, the encapsulating resin composition according to any one of claims 1-5. The content of (C) a tackifier resin, when the nonvolatile matter in the resin composition is 100 mass%, 5 to 80 wt%, for sealing according to any one of claims 1 to 6 Resin composition. The ester bond formed by the reaction of the acid anhydride group of the polyolefin resin (A) modified with the (meth) acrylic acid alkyl ester and the acid anhydride and the epoxy group of the epoxy resin (B) is formed. The encapsulating resin composition according to any one of 1 to 7 . Is for sealing an organic EL device, the encapsulating resin composition according to any one of claims 1-8. A sealing sheet having an adhesive layer formed on a support, wherein the adhesive layer is formed of the sealing resin composition according to any one of claims 1 to 9. Sheet. The encapsulating sheet according to claim 10 , which is for encapsulating an organic EL element. An organic EL device in which an organic EL element is sealed by a sealing layer, wherein the sealing layer is formed by the sealing resin composition according to any one of claims 1 to 10 . , Organic EL devices. An organic EL device in which an organic EL element is sealed by a sealing layer, wherein the sealing layer is formed by the adhesive layer of the sealing sheet according to claim 10 or 11. . A resin varnish containing the encapsulating resin composition according to any one of claims 1 to 9 is applied onto a support and dried by heating to obtain (A) (meth) acrylic acid alkyl ester and an acid anhydride. A method for producing a sealing sheet, which comprises forming an adhesive layer in which an acid anhydride group of the modified polyolefin resin and an epoxy group of the epoxy resin (B) are ester-bonded by a reaction.