JP2010251117A - Transparent sealant for organic el element - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a transparent sealant for an organic EL element excellent in flexibility, capable of fully sealing organic light-emitting elements, and restraining dark spots in case of making an organic EL display panel, and excellent in visibility of images. <P>SOLUTION: The transparent sealant is made of a flexible polymer composition containing hydride of a dienic block copolymer having in its molecule one or more polymer blocks (I) with a mass ratio (a1)/(a2) of conjugated diene compound unit (a1) to an aromatic vinyl compound unit (a2) of 100-50/0-50 and with a vinyl bond content of 60 to 95%, with a ratio of metal contained in the flexible polymer compound of 30 ppm or less, for each kind of metal. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a transparent encapsulant for an organic EL element used for filling a gap on the light emitting surface side of a light emitting element constituting an electroluminescence display panel (hereinafter also simply referred to as “EL display panel”).

  Since the EL element is a self-luminous element, a display device including the EL element has high visibility. Development of a display device such as an organic EL display including an organic EL element capable of lowering an applied voltage than that of an inorganic EL element by using such characteristics is in progress.

  A general organic EL element has a configuration in which an anode layer, a light emitting layer, and a cathode layer are sequentially laminated on a substrate made of glass or the like. In some cases, a functional layer is provided between each layer in order to improve performance. The organic EL element having such a configuration can emit light by energizing between the anode layer and the cathode layer. However, if moisture, impurities, or the like are present around the element, the material constituting the element is eroded and the deterioration proceeds. A display device provided with a deteriorated organic EL element has a problem in that the visibility is remarkably lowered because light emitting defects such as dark spots occur.

  In a normal display device including an organic EL element, the organic EL element is sealed with a transparent substrate (or a sealing can) made of glass or the like. As a method of solving the above problems, a method of disposing a dehydrating agent in a space generated between the organic EL element and the transparent substrate, a method of using a transparent sealing material made of an ultraviolet curable resin, and an inert material containing an adsorbent A method of filling a liquid is disclosed (for example, see Patent Document 1). However, it cannot be said that any method is sufficient in suppressing the occurrence of dark spots. Moreover, since the transparent sealing material which consists of ultraviolet curable resin is hard, fixation of the transparent substrate (or sealing can) in the manufacturing stage of a display apparatus is not easy. Moreover, the case where a transparent substrate (or sealing can) is not fully fixed and the organic EL element is not sufficiently sealed is also assumed.

  On the other hand, in order to solve the above problems, a transparent sealing material formed of a specific elastomer composition having flexibility may be disposed between a light emitting surface of a light emitting element and a sealing member such as a transparent substrate. It is disclosed (for example, see Patent Document 2).

JP-A-9-35868 JP 2005-129520 A

  However, even with the transparent sealing material disclosed in Patent Document 2, the effect of suppressing the occurrence of dark spots is not always sufficient, and further improvement has been required.

  This invention is made | formed in view of the problem which such a prior art has, The place made into the subject is excellent in a softness | flexibility, and can fully seal an organic EL element, and an organic EL display panel is made. An object of the present invention is to provide a transparent encapsulant for organic EL elements that can suppress the occurrence of dark spots when manufactured and is excellent in image visibility.

  As a result of intensive studies to achieve the above-mentioned problems, the inventors of the present invention have reduced the metal content (residual metal ratio) to a predetermined numerical value or less, and a hydride of a diene block copolymer having a specific block structure. The present inventors have found that the above-mentioned problems can be achieved by using a flexible polymer composition containing the present invention, and have completed the present invention.

  That is, according to this invention, the transparent sealing material for organic EL elements shown below is provided.

  [1] The mass ratio of the conjugated diene compound unit (a1) and the aromatic vinyl compound unit (a2) is (a1) / (a2) = 100-50 / 0-50, and the vinyl bond content is 60-95%. It consists of a flexible polymer composition containing a hydride of a diene block copolymer having at least one polymer block (I) in its molecule, and the proportion of the metal contained in the flexible polymer composition is The transparent sealing material for organic EL elements which is 30 ppm or less for every kind of said metal.

  [2] The diene block copolymer is obtained by polymerization in the presence of a polymerization catalyst, and the hydride is obtained by hydrogenation in the presence of a hydrogenation catalyst. The transparent sealing material for organic EL elements according to [1], wherein the metal contained in the flexible polymer composition is derived from at least one of the polymerization catalyst and the hydrogenation catalyst.

  [3] The metal contained in the flexible polymer composition is titanium (Ti), aluminum (Al), lithium (Li), sodium (Na), potassium (K), iron (Fe), and calcium. The transparent sealing material for organic EL elements according to [1] or [2], which is at least one selected from the group consisting of (Ca).

  [4] The diene block copolymer further includes a polymer block (II) made of an aromatic vinyl compound in the molecule, and the mass of the polymer block (I) and the polymer block (II). The transparent sealing material for organic EL elements according to any one of [1] to [3], wherein the ratio is (I) / (II) = 99 to 60/1 to 40.

  [5] The transparent sealing material for organic EL elements according to any one of [1] to [4], wherein a ratio of chlorine (Cl) contained in the flexible polymer composition is 30 ppm or less.

  [6] The transparent sealing material for organic EL elements according to any one of [1] to [5], wherein the total light transmittance at a thickness of 0.5 mm is 90% or more.

  The transparent sealing material for organic EL elements of the present invention is excellent in flexibility, can sufficiently seal the organic EL elements, can suppress the occurrence of dark spots when an organic EL display panel is produced, and The effect of being excellent in the visibility of an image is exhibited.

It is sectional drawing which shows an example of an EL display panel typically. It is sectional drawing which shows the other example of EL display panel typically. It is sectional drawing which shows an example of a light emitting element typically.

  Hereinafter, embodiments of the present invention will be described. However, the present invention is not limited to the following embodiments, and based on ordinary knowledge of those skilled in the art without departing from the spirit of the present invention. It should be understood that modifications, improvements, and the like appropriately added to the embodiments described above fall within the scope of the present invention.

  The transparent sealing material for organic EL elements of the present invention includes a diene block copolymer hydride (hydrogenated polymer) in which the metal content (residual metal ratio) is reduced to a predetermined value or less. It consists of a flexible polymer composition. Hereinafter, the details of the transparent sealing material for organic EL elements of the present invention will be described with specific embodiments. The “flexible polymer composition” in the present specification may contain a hydride of a diene block copolymer described below and other components, or a diene block copolymer. You may consist only of the hydride of a polymer. That is, the transparent sealing material for organic EL elements of the present invention may be formed of a flexible polymer composition containing a hydride of a diene block copolymer and other components described below. However, it may be formed by a flexible polymer composition substantially consisting of a hydride of a diene block copolymer.

(Flexible polymer composition)
The flexible polymer composition is flexible and contains a hydride of a diene copolymer that can produce a transparent molded article. For this reason, the flexible polymer composition constituting the transparent sealing material for an organic EL device of the present invention exhibits sufficient flexibility even when it is a molded body having a desired shape. The space on the light emitting surface side of the light emitting element can be filled without a gap.

  The flexible polymer composition contains a hydride of a diene block copolymer, and when this flexible polymer composition is used, even if it is in close contact with a transparent glass or plastic, etc. Further, it is preferable because a molded article (transparent sealing material for organic EL elements) excellent in transparency that hardly deteriorates in transparency can be formed. In addition, the hydride of a diene type block copolymer can be used individually by 1 type or in combination of 2 or more types.

  The weight average molecular weight (Mw) in terms of polystyrene by GPC of the hydride of the diene block copolymer contained in the flexible polymer composition is not particularly limited, but is usually 1,000 to 1,000,000, Preferably it is 10,000-600,000, More preferably, it is 30,000-400,000.

  The flexible polymer composition includes, for example, ethylene / vinyl acetate copolymer, styrene polymer, polycarbonate, polyacetal, epoxy polymer, etc. in addition to the diene block copolymer hydride described above. A polymer may further be contained.

(Hydride of diene block copolymer)
The diene block copolymer which is a pre-hydrogenation copolymer used for producing a hydride of a diene block copolymer is a block copolymer using a conjugated diene compound as a monomer. The diene block copolymer is preferably a block copolymer of a conjugated diene compound and an aromatic vinyl compound. Specific examples of the conjugated diene compound include 1,3-butadiene, isoprene, 2,3-dimethyl-1,3-butadiene, 1,3-pentadiene, 2-methyl-1,3-pentadiene, and 1,3-hexadiene. 4,5-diethyl-1,3-octadiene, chloroprene and the like. Of these, 1,3-butadiene, isoprene and 1,3-pentadiene are preferable, 1,3-butadiene and isoprene are more preferable, and 1,3-butadiene is particularly preferable. These conjugated diene compounds can be used singly or in combination of two or more.

  Specific examples of the aromatic vinyl compound include styrene, t-butylstyrene, α-methylstyrene, α-chlorostyrene, p-methylstyrene, divinylbenzene, N, N-diethyl-p-aminostyrene, and the like. it can. Of these, styrene and α-methylstyrene are preferable, and styrene is more preferable. These “other monomers” can be used alone or in combination of two or more.

Examples of the diene block copolymer, for _{example, (A-B) m A} , (B-A) m B, (A-B-A) m, and _(B-A-B) by the formula _m such Examples thereof include conjugated diene block copolymers having a block structure represented. Further, the block structure of the conjugated diene block _{copolymer, (A-B) m X} , (B-A) m X, (A-B-A) m X, and _{(B-A-B) m} As represented by a general formula such as X, the polymer molecular chain may be extended or branched via “X” which is a coupling agent residue. In each of the general formulas representing the block structure of the conjugated diene block copolymer, “A” is a block mainly composed of a conjugated diene compound unit, and “B” is a block mainly composed of an aromatic vinyl compound unit. And m is an integer of 1 or more.

  The hydrogenation rate of the hydride of the diene block copolymer is preferably 80% or more, more preferably 85% or more, and particularly preferably 90% or more. The higher the hydrogenation rate of the hydride, the better the light resistance, shape retention, and mechanical properties when formed into a molded body.

  In the diene block copolymer, the mass ratio of the conjugated diene compound unit (a1) and the aromatic vinyl compound unit (a2) is (a1) / (a2) = 99-50 / 1-50, and the vinyl bond content is It has at least one polymer block (I) of 65 to 95% in the molecule. When such a hydride of a diene block copolymer is used, a molded article (transparent sealing material for organic EL elements) having excellent viscoelasticity can be obtained.

  The diene block copolymer has a polymer block (II) composed of an aromatic vinyl compound in its molecule, and when it is a hydride, due to shape retention and mechanical properties. It is preferable because an excellent molded body can be obtained. In particular, styrene / ethylene / butylene / styrene block copolymer, which is a hydrogenated product of styrene / butadiene / styrene block copolymer (SBS) in which the conjugated diene compound is 1,3-butadiene and the aromatic vinyl compound is styrene. Compared to hydrogenated products of other block copolymers, coalesce (SEBS) is a heavy component whose metal content can be efficiently reduced by liquid-liquid extraction (washing) such as purification using an acid described later. It is a coalescence (resin). Therefore, SEBS is a very preferable component as a polymer (resin) contained in the flexible polymer composition constituting the transparent sealing material for an organic EL device of the present invention.

  In the case where the diene block copolymer contains the polymer block (I) and the polymer block (II) in the molecule, the polymer block (I) and the polymer contained in the diene block copolymer The mass ratio of the block (II) is preferably (I) / (II) = 99 to 60/1 to 40, and more preferably (I) / (II) = 97 to 70/3 to 30. Preferably, (I) / (II) = 95 to 80/5 to 20 is particularly preferable. By making the mass ratio of each block contained in the diene block copolymer within the above range, when this diene block copolymer is a hydride, it is particularly excellent in shape retention and mechanical properties. It is preferable because a molded product can be obtained.

As specific examples of the block structure of the diene block copolymer, when the polymer block (I) is “A ¹ ” and the polymer block (II) is “B ¹ ”, A ¹ , (B ¹ − a ¹⁾ _m1, may be mentioned _{^{(B 1 -A 1) m2 -B}} 1, those represented by the general formula, such as _{^{(a 1 -B 1) m3 -A}} 1. In each general formula, m1 to m3 represent an integer of 1 or more.

Diene block _{^{copolymer, (A 1 -B 1) n}} X, (B 1 -A 1) n X, (A 1 -B 1 -A 1) n X, (B 1 -A 1 -B 1 ) As represented by a general formula such as _n X, the polymer molecular chain may be extended or branched via a coupling agent residue “X”. In each general formula, n represents an integer of 2 or more. When a polymer in which n is 3 or more is used as a hydride, it is preferable because a molded product excellent in shape retention and hot melt adhesiveness (adhesiveness) can be obtained. Specific examples of coupling agents that can provide a coupling agent residue “X” include 1,2-dibromoethane, methyldichlorosilane, trichlorosilane, methyltrichlorosilane, tetrachlorosilane, tetramethoxysilane, divinylbenzene, adipic acid Diethyl, dioctyl adipate, benzene-1,2,4-triisocyanate, tolylene diisocyanate, epoxidized 1,2-polybutadiene, epoxidized linseed oil, tetrachlorogermanium, tetrachlorotin, butyltrichlorotin, butyltri Examples include chlorosilane, dimethylchlorosilane, 1,4-chloromethylbenzene, bis (trichlorosilyl) ethane, and the like.

  The hydrogenation of the diene block copolymer is usually performed on the olefinically unsaturated bond contained in the block constituting the diene block copolymer. The hydrogenation of the diene block copolymer can be carried out by methods disclosed in, for example, JP-A-2-133406, JP-A-3-128957, JP-A-5-170844, and the like. it can.

(Metal content)
The ratio of the metal contained in the flexible polymer composition constituting the transparent sealing material for organic EL elements of the present invention is 30 ppm or less. Thus, the metal content (residual metal ratio) is the above value. The transparent sealing material for organic EL elements of the present invention using a flexible polymer composition reduced to a very low level can effectively suppress the occurrence of dark spots when an organic EL display panel is produced. it can. In addition, the organic EL display panel produced using the transparent sealing material for organic EL elements of the present invention is less likely to cause a light-emitting defect such as a dark spot, so that the visibility is difficult to decrease, and good visibility over a long period of time. There is an advantage that sex is sustained. In addition, when several types of metals are contained in a flexible polymer composition, it is necessary for the content rate for each metal to be 30 ppm or less.

  The metal contained in the flexible polymer composition is, for example, (1) a polymerization catalyst used when producing a diene block copolymer by polymerization, and (2) a hydride by hydrogenation. It is derived from at least one of the hydrogenation catalysts used at the time. Examples of these metals include titanium (Ti), aluminum (Al), lithium (Li), sodium (Na), potassium (K), iron (Fe), and calcium (Ca). it can. In addition, lithium (Li) can be mentioned as a typical example of the metal contained in (1) the polymerization catalyst. (2) Typical examples of the metal contained in the hydrogenation catalyst include titanium (Ti), aluminum (Al), and lithium (Li). The smaller the proportion of each metal contained in the flexible polymer composition, the better. The content ratio of any metal is 30 ppm or less, preferably 10 ppm or less, and more preferably 5 ppm or less.

  In order to reduce the metal content ratio of the flexible polymer composition to a predetermined value or less, the flexible polymer composition manufactured according to a conventionally known method is purified using, for example, a predetermined acid. That's fine. The type of acid that can be used for purification is not particularly limited, but specific examples include oxalic acid, lactic acid, malic acid, succinic acid, hydrochloric acid, sulfuric acid, nitric acid, phosphoric acid, citric acid, succinic acid, maleic acid, and pyruvin. An acid etc. can be mentioned. Of these, purification using oxalic acid or lactic acid is preferred.

  For purification using an acid, for example, a solution obtained by dissolving a flexible polymer composition (hydrogenated diene block copolymer) in an appropriate solvent is mixed with an aqueous solution containing an acid. The liquid-liquid extraction is preferably performed an appropriate number of times. The number of times this liquid-liquid extraction is performed is not particularly limited, but it is preferably as many as possible. For example, it is preferably performed twice or more, more preferably three or more times, and particularly preferably four or more times.

  In addition, it is also preferable to wash the flexible polymer composition (hydrogenated product of the diene block copolymer) with water as necessary in order to remove the remaining acid after purification using an acid. Washing with water is performed, for example, by mixing a solution obtained by dissolving a flexible polymer composition (hydrogenated product of a diene block copolymer) in an appropriate solvent and water, and performing liquid-liquid extraction appropriately. It may be performed several times.

(Chlorine content)
The ratio of chlorine (Cl) contained in the flexible polymer composition (residual chlorine ratio) is preferably 30 ppm or less, more preferably 10 ppm or less, and particularly preferably 5 ppm or less. Chlorine (Cl) is a component contained in the flexible polymer composition derived from, for example, a catalyst (hydrogenation catalyst) used in producing a hydride of a diene block copolymer. When the chlorine content of the flexible polymer composition is 30 ppm or less, there is an advantage that damage to the organic EL element can be suppressed and light emission defects are hardly caused.

  In order to reduce the chlorine content ratio of the flexible polymer composition to a predetermined value or less, the flexible polymer composition manufactured according to a conventionally known method may be washed, for example, with water.

(Additive)
The flexible polymer composition constituting the transparent encapsulant for organic EL devices of the present invention may consist essentially of a hydrogenated product of the diene copolymer that has been described above, or is obtained. You may contain an additive in the range which does not impair the transparency of the transparent sealing material for organic EL elements. Additives include softeners, plasticizers, lubricants, cross-linking agents, cross-linking aids, antioxidants, anti-aging agents, heat stabilizers, flame retardants, antibacterial / antifungal agents, weathering agents, UV absorbers, adhesives Examples thereof include an imparting agent, a nucleating agent, a pigment, a dye, and an organic filler.

(Transparent encapsulant for organic EL elements)
Desired by known molding methods such as injection molding, extrusion molding, hollow molding, compression molding, vacuum molding, laminate molding, calendar molding, cast molding, coater molding, roll molding, T-die coater, T-die extrusion molding, injection molding, etc. If it shape | molds using a flexible polymer composition so that it may become the shape of this, the transparent sealing material for organic EL elements of this invention can be obtained. Thus, the molded object (transparent sealing material for organic EL elements) obtained is excellent in transparency. The haze at a thickness of 0.5 mm of the transparent sealing material for organic EL elements of the present invention is usually less than 5%, preferably 4.5% or less, more preferably 4% or less. Further, the total light transmittance at a thickness of 0.5 mm of the transparent sealing material for an organic EL device of the present invention is usually 90% or more, preferably 91% or more, and more preferably 92% or more. In addition, the transparent sealing material for organic EL elements of the present invention can achieve the above-mentioned total light transmittance in a wide temperature range, specifically, a temperature of −100 to 110 ° C., preferably −50 to 100 ° C. In the range, the above-mentioned total light transmittance can be obtained.

The transparent sealing material for organic EL elements of the present invention has excellent strength and flexibility. The shear storage elastic modulus (G ′) of the transparent encapsulant for an organic EL device of the present invention measured using a predetermined dynamic viscoelasticity measuring device under conditions of 30 ° C. and 1 Hz is usually 100,000 dyn. / Cm ² or less, preferably 1,000 dyn / cm ² or less, more preferably 10 dyn / cm ² or less. The shear storage modulus (G ′) is usually 1 dyn / cm ² or more.

  Since the transparent sealing material for organic EL elements of the present invention has the above properties, the entire light emitting element is sealed, and the space inside the EL display panel (the light emitting surface side of the light emitting element) is a gap. It is suitable as a member to be filled without any problems. The shape of the transparent sealing material for organic EL elements of the present invention is not particularly limited, and can be adapted to the shape of the space to be filled. Moreover, it can also be set as the thin body which has a thin part other than a plate-shaped body, a concave-shaped body, etc. In the case of a thin-walled body, the thickness of the thinnest part is preferably 2000 μm or less, more preferably 0.1 to 2000 μm, more preferably 0.1 to 1000 μm, The thickness is particularly preferably 500 μm, and most preferably 0.1 to 100 μm.

  FIG. 1 is a cross-sectional view schematically showing an example of an EL display panel. FIG. 3 is a cross-sectional view schematically showing an example of the light emitting element. As shown in FIGS. 1 and 3, the light emitting element 3 has a configuration in which an anode layer 32, a light emitting layer 33, and a cathode layer 34 are sequentially laminated on a substrate 31. The transparent sealing material 2 for organic EL elements of this embodiment is disposed so as to fill the space between the light emitting surface of the light emitting element 3 (the upper surface of the cathode layer 34) and the sealing member 4 without any gap. That is, in the EL display panel 1, a state in which the organic EL element transparent sealing material 2 is disposed in close contact with both the light emitting surface of the light emitting element 3 and the sealing member 4 is shown. Since the transparent sealing material 2 for an organic EL element of the present embodiment is excellent in flexibility, the light-emitting element 3 can be closely adhered so as to be sufficiently sealed, and the visibility of the image is improved. Can do.

  FIG. 2 is a cross-sectional view schematically showing another example of an EL display panel. As shown in FIG. 2, the organic EL device transparent sealing material 2 is formed together with the light emitting surface of the light emitting device (the upper surface of the cathode layer 34) of the anode layer 32, the light emitting layer 33, and the cathode layer 34 constituting the light emitting device. It can also arrange | position so that the space between each side surface and the sealing member 4 may be filled up without gap.

  The transparent sealing material for organic EL elements of the present invention can maintain the above-described properties for a long time regardless of the state in which it is disposed. That is, the transparent sealing material for organic EL elements of the present invention is extremely less likely to deteriorate with the passage of time of use, and has a very low possibility of damaging the light emitting elements and generating dark spots.

  The material constituting the sealing member 4 as shown in FIGS. 1 and 2 may be any material that does not significantly impair the visibility of the display content of the EL display panel 1. Specific examples of the material constituting the sealing member include glass and resin. Specific examples of the glass include borosilicate glass, aluminosilicate glass, aluminoborosilicate glass, silica glass, low alkali glass, and soda lime glass. Specific examples of the resin include polycarbonate resins, polyacetal resins, 1,2-polybutadiene resins, preferably ethylene / vinyl acetate copolymers containing 3% by mass or more of vinyl acetate units, olefins such as polyethylene and polypropylene. Resins, styrene resins, acrylic resins, vinyl ester resins, saturated polyester resins, polyamide resins, fluororesins such as polyvinylidene fluoride, urethane resins, epoxy resins, unsaturated polyester resins, silicone resins, etc. Can be mentioned. The shape of the sealing member 4 may be a plate shape as shown in FIG. 1, or a lid that covers the light emitting members (anode layer 32, light emitting layer 33, cathode layer 34) and the like as shown in FIG. It may be a mold shape.

  EXAMPLES Hereinafter, although this invention is demonstrated concretely based on an Example, this invention is not limited to these Examples. In the examples and comparative examples, “parts” and “%” are based on mass unless otherwise specified.

1. Methods for measuring various physical properties and methods for evaluating various properties:
[Hydrogenation rate]: Calculated from 100 MHz, ¹ H-NMR spectrum using carbon tetrachloride as a solvent.

  [Weight Average Molecular Weight (Mw)]: Calculated in terms of polystyrene using gel permeation chromatography (GPC) at 40 ° C. using tetrahydrofuran as a solvent.

[Bound styrene content]: Calculated from 270 MHz, ¹ H-NMR spectrum using carbon tetrachloride as a solvent.

  [Vinyl bond content]: Calculated by the Morero method using infrared analysis.

  [Melt flow rate (MFR)]: Measured according to JIS K7210 at 230 ° C. and a load of 21.2 N.

  [Metal content ratio (residual metal ratio)]: The metal content ratio (ppm) was measured using an inductively coupled plasma optical emission spectrometer (trade name “CIROS-120”, manufactured by Rigaku / SPECTRO).

  [Chlorine content ratio (residual chlorine ratio)]: A chlorine content ratio (ppm) was measured using a fluorescent X-ray analyzer (trade name “Panalytic MagixPRO”, manufactured by Spectris).

  [Outgas ratio]: Thermal desorption purge and trap (trade name “JTD-505II”, manufactured by Nippon Analytical Industries, Ltd.), gas chromatograph (“trade name“ HP6890 ”, manufactured by Agilent Technologies), and quadrupole mass spectrometer A headspace gas chromatography apparatus equipped with “JMS-Q1000GC K9” (manufactured by JEOL Ltd.) was used, and the outgas ratio (ppm) extracted at 120 ° C. for 15 minutes was measured.

  [Haze and total light transmittance]: 0.5 mm thick thin body (organic EL) between two sheets of melt-formed aluminosilicate sheet glass (trade name “Corning 1737”, manufactured by Corning) with a thickness of 0.7 mm Using a total light transmittance haze measuring device (trade name “Haze-gard plus 4725”, manufactured by BYK-Gardner) with a sandwiched element (transparent sealing material for elements) as a measurement target, the haze at 25 ° C. (% ) And total light transmittance (%).

  [Transparency]: A case where the haze was less than 5% was evaluated as “◯” as being excellent in transparency. Moreover, when the haze was 5% or more, it was evaluated as “x” because the transparency was inferior.

  [Visibility of the image]: The printed material can be closely adhered to a 0.5 mm-thick thin body (transparent sealing material for organic EL elements) to visually observe the printed material, and the image of the printed material can be visually recognized in a good state. Was evaluated as “◯”, and the printed image was evaluated as “x” when it was impossible to visually recognize the image in a good state.

  [Sealing property]: As shown in FIG. 3, the anode layer 32, the light emitting layer 33, and the cathode layer 34 were sequentially laminated on the upper surface of the substrate 31 made of insulating transparent glass to produce the light emitting element 3. Next, as shown in FIG. 1, the transparent sealing material 2 for organic EL elements (a thin body having a thickness of 0.5 mm) is allowed to stand on the upper surface of the cathode layer 34 and the sealing member made of insulating transparent glass. 4 was installed on the upper surface of the transparent sealing material 2 for organic EL elements, and the model of the EL display panel 1 was produced. The case where the polymer which comprises the transparent sealing material 2 for organic EL elements was favorable and was able to seal without producing a space | gap inside the model of EL display panel 1 was evaluated as "(circle)". On the other hand, the case where the polymer which comprises the transparent sealing material 2 for organic EL elements was not flexible, and the space | gap produced in the model of EL display panel 1 was evaluated as "x".

  [Inhibition of generation of dark spots]: The model (see FIG. 1) of the EL display panel 1 produced in the “sealing property” was heated at 80 ° C. for 500 hours. After cooling to room temperature (25 ° C.), the light emitting element 3 was activated to observe the presence or absence of dark spots (non-light emitting portions). The case where the area ratio of the dark spot was less than 5% with respect to the entire light emitting surface (upper surface) of the light emitting element 3 was evaluated as “◯”. On the other hand, the case where the area ratio of the dark spots was 5% or more with respect to the entire light emitting surface (upper surface) of the light emitting element 3 was evaluated as “x”.

2. Polymer synthesis:
(Polymer A)
In a reaction vessel purged with nitrogen, 360 parts of degassed and dehydrated cyclohexane, 9 parts of styrene, and 16 parts of tetrahydrofuran were charged, and 0.11 part of n-butyllithium was added at a polymerization start temperature of 40 ° C. Adiabatic polymerization was performed. After the polymerization conversion rate reached about 100%, the reaction solution was cooled to 2 ° C., and then 65 parts of 1,3-butadiene and 20 parts of styrene were added to perform adiabatic polymerization. After the polymerization conversion reached about 100%, 6 parts of styrene was further added to conduct adiabatic polymerization. After the polymerization conversion rate reached about 100%, it was left for 10 minutes while supplying hydrogen gas at a pressure of 0.4 MPa-Gauge.

  After adding 0.014 part of tetrachlorosilane in the reaction vessel and stirring for 10 minutes, 0.034 part of diethylaluminum chloride and 0.52 part of bis (cyclopentadienyl) titanium furfuryloxychloride were further added. Stir. Hydrogenation reaction was started at a hydrogen gas supply pressure of 0.7 MPa-Gauge and a reaction temperature of 80 ° C. When the absorption of hydrogen gas was completed, the temperature and pressure of the reaction solution were returned to room temperature and normal pressure, and the reaction solution was extracted from the reaction vessel. The extracted reaction solution was stirred into water, and the solvent was removed by steam distillation to obtain a hydrogenated block copolymer. The resulting hydrogenated block copolymer had a hydrogenation rate of 98%, a weight average molecular weight (Mw) of 300,000, a bound styrene content of 10%, a vinyl bond content of 80%, and an MFR of 3.5 g / 10 min. Met.

  To the resulting hydrogenated block copolymer, 900 parts of cyclohexane was added and stirred to obtain a hydrogenated block copolymer solution. (1) To the obtained solution, 1 part of oxalic acid and 100 parts of methanol were added and stirred at 55 ° C. for 1 hour, and then 400 parts of water and 100 parts of methanol were further added and stirred at room temperature. After standing for 1 hour, the water / methanol layer of the separated two layers was removed (liquid-liquid extraction). After the operation (liquid-liquid extraction) of (1) was repeated 4 times, (2) 400 parts of water and 200 parts of methanol were added to the cyclohexane layer and stirred at room temperature for 1 hour. After standing for 1 hour, the water / methanol layer of the separated two layers was removed (washed with water). After repeating the operation (2) of the above (2) 6 times, the polymer A was obtained by removing the solvent by steam distillation. The resulting polymer A has a metal content of Ti of 0.1 ppm, Al of 0.4 ppm, Li of 0.1 ppm, Na of 0.3 ppm, K of 0.1 ppm, Fe of 0.5 ppm, and Ca of 1.3 ppm, Mg was 0.2 ppm, P was 0.4 ppm, and Ni was 0.4 ppm. Moreover, the chlorine content rate of the obtained polymer A was 0.1 ppm, and the amount of outgases was 7.1 ppm.

(Polymer B)
In a nitrogen-substituted reaction vessel, 450 parts of degassed and dehydrated cyclohexane, 4 parts of styrene, and 16 parts of tetrahydrofuran were charged, and 0.055 part of n-butyllithium was added at a polymerization start temperature of 40 ° C. Temperature programmed polymerization was performed. After the polymerization conversion rate reached about 100%, the reaction solution was cooled to 10 ° C., and then 90 parts of 1,3-butadiene and 4 parts of styrene were added to carry out temperature rising polymerization. After the polymerization conversion reached about 100%, 2 parts of styrene was further added to carry out temperature rising polymerization. After the polymerization conversion rate reached about 100%, it was left for 10 minutes while supplying hydrogen gas at a pressure of 0.4 MPa-Gauge.

  After adding 0.014 part of tetrachlorosilane in the reaction vessel and stirring for 10 minutes, 0.034 part of diethylaluminum chloride and 0.52 part of bis (cyclopentadienyl) titanium furfuryloxychloride were further added. Stir. Hydrogenation reaction was started at a hydrogen gas supply pressure of 0.7 MPa-Gauge and a reaction temperature of 80 ° C. When the absorption of hydrogen gas was completed, the temperature and pressure of the reaction solution were returned to room temperature and normal pressure, and the reaction solution was extracted from the reaction vessel. The extracted reaction solution was stirred into water, and the solvent was removed by steam distillation to obtain a hydrogenated block copolymer. The resulting hydrogenated block copolymer had a hydrogenation rate of 98%, a weight average molecular weight (Mw) of 300,000, a bound styrene content of 10%, a vinyl bond content of 80%, and an MFR of 30 g / 10 min. It was.

  To the resulting hydrogenated block copolymer, 900 parts of cyclohexane was added and stirred to obtain a hydrogenated block copolymer solution. (1) To the obtained solution, 1 part of oxalic acid and 100 parts of methanol were added and stirred at 55 ° C. for 1 hour, and then 400 parts of water and 100 parts of methanol were further added and stirred at room temperature. After standing for 1 hour, the water / methanol layer of the separated two layers was removed (liquid-liquid extraction). After the operation (liquid-liquid extraction) of (1) was repeated 4 times, (2) 400 parts of water and 200 parts of methanol were added to the cyclohexane layer and stirred at room temperature for 1 hour. After standing for 1 hour, the water / methanol layer of the separated two layers was removed (washed with water). After repeating the operation (2) of the above (2) 6 times, the solvent was removed by steam distillation to obtain a polymer B. Table 1 shows the measurement results of the metal content ratio, chlorine content ratio, and outgas amount of the obtained polymer B.

(Polymer C)
In a reaction vessel purged with nitrogen, 450 parts of degassed and dehydrated cyclohexane, 9 parts of styrene, and 11 parts of tetrahydrofuran were charged, and 0.11 part of n-butyllithium was added at a polymerization start temperature of 40 ° C. Temperature programmed polymerization was performed. After the polymerization conversion rate reached about 100%, the reaction solution was cooled to 10 ° C., and then 85 parts of 1,3-butadiene was added to carry out temperature rising polymerization. After the polymerization conversion rate reached about 100%, 6 parts of styrene was further added to carry out temperature rising polymerization. After the polymerization conversion rate reached about 100%, it was left for 10 minutes while supplying hydrogen gas at a pressure of 0.4 MPa-Gauge.

  After adding 0.047 part of tetrachlorosilane in the reaction vessel and stirring for 10 minutes, 0.024 part of diethylaluminum chloride and 0.05 part of bis (cyclopentadienyl) titanium furfuryloxychloride were further added. Stir. Hydrogenation reaction was started at a hydrogen gas supply pressure of 0.7 MPa-Gauge and a reaction temperature of 80 ° C. When the absorption of hydrogen gas was completed, the temperature and pressure of the reaction solution were returned to room temperature and normal pressure, and the reaction solution was extracted from the reaction vessel. The extracted reaction solution was stirred into water, and the solvent was removed by steam distillation to obtain a hydrogenated block copolymer. The resulting hydrogenated block copolymer had a hydrogenation rate of 98%, a weight average molecular weight (Mw) of 125,000, a bound styrene content of 15%, a vinyl bond content of 79%, and an MFR of 30 g / 10 min. Met.

  To the resulting hydrogenated block copolymer, 900 parts of cyclohexane was added and stirred to obtain a hydrogenated block copolymer solution. (1) To the obtained solution, 1 part of oxalic acid and 100 parts of methanol were added and stirred at 55 ° C. for 1 hour, and then 400 parts of water and 100 parts of methanol were further added and stirred at room temperature. After standing for 1 hour, the water / methanol layer of the separated two layers was removed (liquid-liquid extraction). After the operation (liquid-liquid extraction) of (1) was repeated 4 times, (2) 400 parts of water and 200 parts of methanol were added to the cyclohexane layer and stirred at room temperature for 1 hour. After standing for 1 hour, the water / methanol layer of the separated two layers was removed (washed with water). After repeating the operation (2) of (2) 6 times, the polymer C was obtained by removing the solvent by steam distillation. Table 1 shows the measurement results of the metal content ratio, the chlorine content ratio, and the outgas amount of the obtained polymer C.

(Polymer D)
In a reaction vessel purged with nitrogen, 400 parts of degassed and dehydrated cyclohexane, 9 parts of styrene, and 3.8 parts of tetrahydrofuran were charged, and 0.11 part of n-butyllithium was added at a polymerization start temperature of 40 ° C. Then, temperature rising polymerization was performed. After the polymerization conversion rate reached about 100%, the reaction solution was cooled to 10 ° C., and then 85 parts of 1,3-butadiene was added to carry out temperature rising polymerization. After the polymerization conversion rate reached about 100%, 6 parts by mass of styrene was further added to carry out temperature rising polymerization. After the polymerization conversion rate reached about 100%, it was left for 10 minutes while supplying hydrogen gas at a pressure of 0.4 MPa-Gauge.

  After adding 0.047 part of tetrachlorosilane in the reaction vessel and stirring for 10 minutes, 0.024 part of diethylaluminum chloride and 0.05 part of bis (cyclopentadienyl) titanium furfuryloxychloride were further added. Stir. Hydrogenation reaction was started at a hydrogen gas supply pressure of 0.7 MPa-Gauge and a reaction temperature of 80 ° C. When the absorption of hydrogen gas was completed, the temperature and pressure of the reaction solution were returned to room temperature and normal pressure, and the reaction solution was extracted from the reaction vessel. The extracted reaction solution was stirred into water, and the solvent was removed by steam distillation to obtain a hydrogenated block copolymer. The resulting hydrogenated block copolymer had a hydrogenation rate of 98%, a weight average molecular weight (Mw) of 125,000, a bound styrene content of 15%, a vinyl bond content of 64%, and an MFR of 3.5 g / It was 10 minutes.

  To the resulting hydrogenated block copolymer, 900 parts of cyclohexane was added and stirred to obtain a hydrogenated block copolymer solution. (1) To the obtained solution, 1 part of oxalic acid and 100 parts of methanol were added and stirred at 55 ° C. for 1 hour, and then 400 parts of water and 100 parts of methanol were further added and stirred at room temperature. After standing for 1 hour, the water / methanol layer of the separated two layers was removed (liquid-liquid extraction). After the operation (liquid-liquid extraction) of (1) was repeated 4 times, (2) 400 parts of water and 200 parts of methanol were added to the cyclohexane layer and stirred at room temperature for 1 hour. After standing for 1 hour, the water / methanol layer of the separated two layers was removed (washed with water). After repeating the operation (2) of the above (2) 6 times, the polymer D was obtained by removing the solvent by steam distillation. Table 1 shows the measurement results of the metal content ratio, chlorine content ratio, and outgas amount of the obtained polymer D.

(Polymer E)
In a reaction vessel purged with nitrogen, 450 parts of degassed and dehydrated cyclohexane, 9 parts of styrene, and 11 parts of tetrahydrofuran were charged, and 0.11 part of n-butyllithium was added at a polymerization start temperature of 40 ° C. Temperature programmed polymerization was performed. After the polymerization conversion rate reached about 100%, the reaction solution was cooled to 10 ° C., and then 83 parts of 1,3-butadiene was added to carry out temperature rising polymerization. After the polymerization conversion rate reached about 100%, 6 parts of styrene was further added to carry out temperature rising polymerization. After the polymerization conversion reached about 100%, 2 parts of 1,3-butadiene and 0.364 part of N, N-bis (trimethylsilyl) aminopropylmethyldiethoxysilane were further added and reacted for 30 minutes. Next, it was left to stand for 10 minutes while supplying hydrogen gas at a pressure of 0.4 MPa-Gauge.

  After adding 0.047 part of tetrachlorosilane in the reaction vessel and stirring for 10 minutes, 0.1505 part of diethylaluminum chloride, 0.1213 part of bis (cyclopentadienyl) titanium furfuryloxychloride, and n-butyllithium 0.0323 part was further added and stirred. Hydrogenation reaction was started at a hydrogen gas supply pressure of 0.7 MPa-Gauge and a reaction temperature of 80 ° C. When the absorption of hydrogen gas was completed, the temperature and pressure of the reaction solution were returned to room temperature and normal pressure, and the reaction solution was extracted from the reaction vessel. The extracted reaction solution was stirred into water, and the solvent was removed by steam distillation to obtain a hydrogenated block copolymer. The resulting hydrogenated block copolymer had a hydrogenation rate of 98%, a weight average molecular weight (Mw) of 125,000, a bound styrene content of 15%, a vinyl bond content of 79%, and an MFR of 30 g / 10 min. Met.

  To the resulting hydrogenated block copolymer, 900 parts of cyclohexane was added and stirred to obtain a hydrogenated block copolymer solution. (1) To the obtained solution, 1 part of oxalic acid and 100 parts of methanol were added and stirred at 55 ° C. for 1 hour, and then 400 parts of water and 100 parts of methanol were further added and stirred at room temperature. After standing for 1 hour, the water / methanol layer of the separated two layers was removed (liquid-liquid extraction). After the operation (liquid-liquid extraction) of (1) was repeated 4 times, (2) 400 parts of water and 200 parts of methanol were added to the cyclohexane layer and stirred at room temperature for 1 hour. After standing for 1 hour, the water / methanol layer of the separated two layers was removed (washed with water). After repeating the operation (2) of (2) 6 times, the solvent was removed by steam distillation to obtain a polymer E. Table 1 shows the measurement results of the metal content ratio, chlorine content ratio, and outgas amount of the obtained polymer E.

(Polymer F)
In a reaction vessel purged with nitrogen, 360 parts of degassed and dehydrated cyclohexane, 9 parts of styrene, and 16 parts of tetrahydrofuran were charged, and 0.11 part of n-butyllithium was added at a polymerization start temperature of 40 ° C. Adiabatic polymerization was performed. After the polymerization conversion rate reached about 100%, the reaction solution was cooled to 2 ° C., and then 65 parts of 1,3-butadiene and 20 parts of styrene were added to perform adiabatic polymerization. After the polymerization conversion reached about 100%, 6 parts of styrene was further added to conduct adiabatic polymerization. After the polymerization conversion rate reached about 100%, it was left for 10 minutes while supplying hydrogen gas at a pressure of 0.4 MPa-Gauge.

  After adding 0.014 part of tetrachlorosilane in the reaction vessel and stirring for 10 minutes, 0.034 part of diethylaluminum chloride and 0.52 part of bis (cyclopentadienyl) titanium furfuryloxychloride were further added. Stir. Hydrogenation reaction was started at a hydrogen gas supply pressure of 0.7 MPa-Gauge and a reaction temperature of 80 ° C. When the absorption of hydrogen gas was completed, the temperature and pressure of the reaction solution were returned to room temperature and normal pressure, and the reaction solution was extracted from the reaction vessel. The extracted reaction solution was stirred into water, and the solvent was removed by steam distillation to obtain a hydrogenated block copolymer. The resulting hydrogenated block copolymer had a hydrogenation rate of 98%, a weight average molecular weight (Mw) of 300,000, a bound styrene content of 10%, a vinyl bond content of 80%, and an MFR of 3.5 g / 10 min. Met.

  To the resulting hydrogenated block copolymer, 900 parts of cyclohexane was added and stirred to obtain a hydrogenated block copolymer solution. (1) To the obtained solution, 1 part of oxalic acid and 100 parts of methanol were added and stirred at 55 ° C. for 1 hour, and then 400 parts of water and 100 parts of methanol were further added and stirred at room temperature. After standing for 1 hour, the water / methanol layer of the separated two layers was removed (liquid-liquid extraction).

  After the operation (liquid-liquid extraction) of (1) was repeated twice, (2) 400 parts of water and 200 parts of methanol were added to the cyclohexane layer and stirred at room temperature for 1 hour. After standing for 1 hour, the water / methanol layer of the separated two layers was removed (washed with water). After repeating the operation (2) of the above (2) three times, the polymer F was obtained by removing the solvent by steam distillation. Table 1 shows the measurement results of the metal content ratio, chlorine content ratio, and outgas amount of the obtained polymer F.

(Polymer G)
In a reaction vessel purged with nitrogen, 360 parts of degassed and dehydrated cyclohexane, 9 parts of styrene, and 16 parts of tetrahydrofuran were charged, and 0.11 part of n-butyllithium was added at a polymerization start temperature of 40 ° C. Adiabatic polymerization was performed. After the polymerization conversion rate reached about 100%, the reaction solution was cooled to 2 ° C., and then 65 parts of 1,3-butadiene and 20 parts of styrene were added to perform adiabatic polymerization. After the polymerization conversion reached about 100%, 6 parts of styrene was further added to conduct adiabatic polymerization. After the polymerization conversion rate reached about 100%, it was left for 10 minutes while supplying hydrogen gas at a pressure of 0.4 MPa-Gauge.

  After adding 0.014 part of tetrachlorosilane in the reaction vessel and stirring for 10 minutes, 0.034 part of diethylaluminum chloride and 0.52 part of bis (cyclopentadienyl) titanium furfuryloxychloride were further added. Stir. Hydrogenation reaction was started at a hydrogen gas supply pressure of 0.7 MPa-Gauge and a reaction temperature of 80 ° C. When the absorption of hydrogen gas was completed, the temperature and pressure of the reaction solution were returned to room temperature and normal pressure, and the reaction solution was extracted from the reaction vessel. The extracted reaction solution was stirred into water, and the solvent was removed by steam distillation to obtain a hydrogenated block copolymer. The obtained hydrogenated block copolymer had a hydrogenation rate of 98%, a weight average molecular weight (Mw) of 300,000, a bound styrene content of 10%, a vinyl bond content of 80%, and an MFR of 3.5 g / 10 min. Met.

  To the resulting hydrogenated block copolymer, 900 parts of cyclohexane was added and stirred to obtain a hydrogenated block copolymer solution. (1) After adding 1 part of lactic acid and 100 parts of methanol to the obtained solution and stirring at 55 ° C. for 1 hour, 400 parts of water and 100 parts of methanol were further added and stirred at room temperature. After standing for 1 hour, the water / methanol layer of the separated two layers was removed (liquid-liquid extraction). After the operation (liquid-liquid extraction) of (1) was repeated 4 times, (2) 400 parts of water and 200 parts of methanol were added to the cyclohexane layer and stirred at room temperature for 1 hour. After standing for 1 hour, the water / methanol layer of the separated two layers was removed (washed with water). After repeating the operation (2) of the above (2) 6 times, the polymer G was obtained by removing the solvent by steam distillation. Table 1 shows the measurement results of the metal content ratio, chlorine content ratio, and outgas amount of the obtained polymer G.

(Polymer H)
In a reaction vessel purged with nitrogen, 360 parts of degassed and dehydrated cyclohexane, 9 parts of styrene, and 16 parts of tetrahydrofuran were charged, and 0.11 part of n-butyllithium was added at a polymerization start temperature of 40 ° C. Adiabatic polymerization was performed. After the polymerization conversion rate reached about 100%, the reaction solution was cooled to 2 ° C., and then 65 parts of 1,3-butadiene and 20 parts of styrene were added to perform adiabatic polymerization. After the polymerization conversion reached about 100%, 6 parts of styrene was further added to conduct adiabatic polymerization. After the polymerization conversion rate reached about 100%, it was left for 10 minutes while supplying hydrogen gas at a pressure of 0.4 MPa-Gauge.

  After adding 0.014 part of tetrachlorosilane in the reaction vessel and stirring for 10 minutes, 0.034 part of diethylaluminum chloride and 0.52 part of bis (cyclopentadienyl) titanium furfuryloxychloride were further added. Stir. Hydrogenation reaction was started at a hydrogen gas supply pressure of 0.7 MPa-Gauge and a reaction temperature of 80 ° C. When the absorption of hydrogen gas was completed, the temperature and pressure of the reaction solution were returned to room temperature and normal pressure, and the reaction solution was extracted from the reaction vessel. The extracted reaction solution was stirred into water, and the solvent was removed by steam distillation to obtain a hydrogenated block copolymer. The resulting hydrogenated block copolymer had a hydrogenation rate of 98%, a weight average molecular weight (Mw) of 300,000, a bound styrene content of 10%, a vinyl bond content of 80%, and an MFR of 3.5 g / 10 min. Met. This hydrogenated block copolymer was designated as “polymer H”. Table 1 shows the measurement results of the metal content ratio, chlorine content ratio, and outgas amount of polymer H.

(Polymer I)
In a reaction vessel purged with nitrogen, 360 parts of degassed and dehydrated cyclohexane, 9 parts of styrene, and 16 parts of tetrahydrofuran were charged, and 0.11 part of n-butyllithium was added at a polymerization start temperature of 40 ° C. Adiabatic polymerization was performed. After the polymerization conversion rate reached about 100%, the reaction solution was cooled to 2 ° C., and then 65 parts of 1,3-butadiene and 20 parts of styrene were added to perform adiabatic polymerization. After the polymerization conversion reached about 100%, 6 parts of styrene was further added to conduct adiabatic polymerization. After the polymerization conversion rate reached about 100%, it was left for 10 minutes while supplying hydrogen gas at a pressure of 0.4 MPa-Gauge.

  After adding 0.014 part of tetrachlorosilane in the reaction vessel and stirring for 10 minutes, 0.034 part of diethylaluminum chloride and 0.52 part of bis (cyclopentadienyl) titanium furfuryloxychloride were further added. Stir. Hydrogenation reaction was started at a hydrogen gas supply pressure of 0.7 MPa-Gauge and a reaction temperature of 80 ° C. When the absorption of hydrogen gas was completed, the temperature and pressure of the reaction solution were returned to room temperature and normal pressure, and the reaction solution was extracted from the reaction vessel. The extracted reaction solution was stirred into water, and the solvent was removed by steam distillation to obtain a hydrogenated block copolymer. The resulting hydrogenated block copolymer had a hydrogenation rate of 98%, a weight average molecular weight (Mw) of 300,000, a bound styrene content of 10%, a vinyl bond content of 80%, and an MFR of 3.5 g / 10 min. Met.

  To the resulting hydrogenated block copolymer, 900 parts of cyclohexane was added and stirred to obtain a hydrogenated block copolymer solution. (1) 400 parts of water and 200 parts of methanol were added to the obtained solution, and stirred at room temperature for 1 hour. After standing for 1 hour, the water / methanol layer of the separated two layers was removed (washed with water). After repeating the operation of (1) (washing with water) six times, the solvent was removed by steam distillation to obtain a polymer I. Table 1 shows the measurement results of the metal content ratio, chlorine content ratio, and outgas amount of the obtained polymer I.

3. Production of transparent sealing material for organic EL elements:
Example 1
By coating the polymer A with a coater, a transparent sealing material for organic EL elements (Example 1), which is a plate-like thin body having a thickness of 0.5 mm, was produced. The produced transparent encapsulant for organic EL devices has a haze of 2.6%, a total light transmittance of 94%, a transparency evaluation result of “◯”, a visibility evaluation result of “○”, and a shear storage modulus G. '(30 ° C) is 487000 dyn / cm ² , shear storage modulus G' (70 ° C) is 485000 dyn / cm ² , the sealing property evaluation result is "◯", and the dark spot generation inhibition evaluation result is "○ "Met.

(Examples 2-7, Comparative Examples 1 and 2)
An organic EL element which is a plate-like thin body having a thickness of 0.5 mm in the same manner as in Example 1 except that the polymers B to I were respectively formed by coater instead of the polymer A. Transparent sealing materials (Examples 2 to 7, Comparative Examples 1 and 2) were produced. Table 2 shows the measurement results of various physical properties and the evaluation results of various properties of the produced transparent sealing material for organic EL elements.

4). About evaluation results:
From the results shown in Table 2, the transparent sealing material for organic EL elements of Comparative Example 1 is not good in transparency, and the image visibility is slightly inferior to other transparent sealing materials for organic EL elements. It is clear that there is. Moreover, the transparent sealing material for organic EL elements of Comparative Examples 1 and 2 both had a large area ratio of dark spots. On the other hand, the transparent sealing materials for organic EL elements of Examples 1 to 7 are both excellent in transparency and flexibility, and are in close contact with each other without causing voids in the model of the EL display panel. It is clear that it can be sealed. Moreover, while the transparent sealing material for organic EL elements of Examples 1-7 is all excellent in the visibility of an image, it is a dark spot compared with the transparent sealing material for organic EL elements of Comparative Examples 1 and 2. It is clear that the occurrence of is sufficiently suppressed.

  The transparent sealing material for organic EL elements of the present invention can be suitably used for an organic EL display panel with high visibility. The transparent sealing material for organic EL elements of the present invention can also be suitably used for mobile phones, personal digital assistants, desktop computers, notebook computers, televisions, in-vehicle information devices, watches, and the like. .

1: EL display panel, 2: Transparent sealing material for organic EL element, 3: Light emitting element, 4: Sealing member, 5: Housing, 31: Substrate, 32: Anode layer, 33: Light emitting layer, 34: Cathode layer

Claims (6)

Polymer in which the mass ratio of the conjugated diene compound unit (a1) and the aromatic vinyl compound unit (a2) is (a1) / (a2) = 100-50 / 0-50 and the vinyl bond content is 60-95% A flexible polymer composition containing a hydride of a diene block copolymer having at least one block (I) in its molecule;
The transparent sealing material for organic EL elements whose ratio of the metal contained in the said flexible polymer composition is 30 ppm or less for every kind of said metal. The diene block copolymer is obtained by polymerization in the presence of a polymerization catalyst, and the hydride is obtained by hydrogenation in the presence of a hydrogenation catalyst,
The transparent sealing material for organic EL elements according to claim 1, wherein the metal contained in the flexible polymer composition is derived from at least one of the polymerization catalyst and the hydrogenation catalyst.   The metal contained in the flexible polymer composition is titanium (Ti), aluminum (Al), lithium (Li), sodium (Na), potassium (K), iron (Fe), and calcium (Ca). The transparent sealing material for organic EL elements according to claim 1 or 2, which is at least one selected from the group consisting of: The diene block copolymer is
The polymer block (II) made of an aromatic vinyl compound is further included in the molecule, and the mass ratio of the polymer block (I) to the polymer block (II) is (I) / (II) = 99. It is -50 / 1-50. The transparent sealing material for organic EL elements as described in any one of Claims 1-3.   The organic EL element sealing material according to any one of claims 1 to 4, wherein a ratio of chlorine (Cl) contained in the flexible polymer composition is 30 ppm or less.   The total light transmittance in thickness 0.5mm is 90% or more, The transparent sealing material for organic EL elements as described in any one of Claims 1-5.

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