Resin composition and resin sheet

Abstract

Provided are: a resin composition containing a polyolefin-based resin and semi-calcined hydrotalcite, wherein the content of the semi-calcined hydrotalcite is more than 45 mass% with respect to 100 mass% of nonvolatile matters in the resin composition, and the water content with respect to the total of the resin composition is 2,500 ppm or less in terms of mass; and a resin sheet using the resin composition.

Description

[Technical Field]

[0001] The present invention relates to a resin composition useful for encapsulating electronic devices and a resin sheet using the same. [Background technology]

[0002] To protect electronic devices such as organic electroluminescence (EL) devices and solar cells from moisture, these devices are often encapsulated using resin compositions.

[0003] Resin compositions suitable for encapsulating electronic devices are known to contain hygroscopic fillers. For example, Patent Document 1 discloses an encapsulating resin composition containing a hygroscopic metal hydroxide and an encapsulating sheet comprising a support and a resin composition layer formed from the encapsulating resin composition. [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] International Publication No. 2017 / 057708 [Overview of the project] [Problems that the invention aims to solve]

[0005] In the field of electronic devices, there has been an ongoing demand for improving the encapsulation performance of resin compositions used for encapsulating electronic devices (specifically, the performance of suppressing deterioration of the encapsulated site). A resin composition containing a polyolefin-based resin and semi-calcined hydrotalcite is excellent in moisture permeability resistance and transparency and is useful for encapsulating electronic devices. However, when the content of semi-calcined hydrotalcite in the resin composition is increased to improve moisture permeability resistance, despite the increase in the content of semi-calcined hydrotalcite, which is a hygroscopic filler, the deterioration of the encapsulated site over time increases, and it has been found that there is a limit to improving the encapsulation performance. The present invention has been made paying attention to such circumstances, and an object thereof is to provide a resin composition having excellent encapsulation performance and a resin sheet using the same.

Means for Solving the Problems

[0006] As a result of intensive studies by the present inventors, it has been found that the moisture trapped in the semi-calcined hydrotalcite reaches the encapsulated site over time and causes its deterioration, and when the content of semi-calcined hydrotalcite increases, this deterioration becomes apparent. Also, in order to improve the encapsulation performance, while increasing the content of semi-calcined hydrotalcite to improve moisture permeability resistance, it has been found that by reducing the internal moisture content in the resin composition brought in by the semi-calcined hydrotalcite, improvement in the encapsulation performance (suppression of moisture permeability resistance and deterioration of the encapsulated site due to internal moisture) can be achieved.

[0007] The present invention based on the above findings is as follows. [1] A resin composition containing a polyolefin-based resin and semi-calcined hydrotalcite, wherein the content of the semi-calcined hydrotalcite is more than 45% by mass based on 100% by mass of the non-volatile content of the resin composition, and the moisture content is 2,500 ppm or less on a mass basis with respect to the entire resin composition. [2] The resin composition according to [1] above, wherein the moisture content is 2,000 ppm or less on a mass basis with respect to the entire resin composition. [3] The resin composition according to [1] or [2], wherein the content of the semi-calcined hydrotalcite is more than 45% by mass and 80% by mass or less based on 100% by mass of the non-volatile content of the resin composition. [4] The resin composition according to any one of [1] to [3] above, which is used for sealing an electronic device. [5] The resin composition according to [4] above, wherein the electronic device is an organic EL device or a solar cell. [6] A resin sheet having a support and a layer of the resin composition according to any one of [1] to [3] provided on the support. [7] The resin sheet according to [6] above, which is used for sealing an electronic device. [8] The resin sheet according to [7] above, wherein the electronic device is an organic EL device or a solar cell. [The effects of the invention]

[0008] According to the present invention, a resin composition excellent in the sealing performance of an electronic device and a resin sheet using the same can be obtained. [Modes for carrying out the invention]

[0009] Hereinafter, the present invention will be described in order. The examples, preferred embodiments, etc. described below can be combined with each other as long as they do not conflict with each other.

[0010] [Resin composition] The resin composition of the present invention contains a polyolefin resin and a semi-calcined hydrotalcite. The sealing layer formed from the resin composition containing the semi-calcined hydrotalcite can suppress the deterioration of the electronic device due to moisture invading from the outside air because the semi-calcined hydrotalcite absorbs moisture in the outside air.

[0011] However, in a encapsulation layer formed from a resin composition containing semi-calcined hydrotalcite, moisture captured by the semi-calcined hydrotalcite (possibly interlayer water in the semi-calcined hydrotalcite and moisture adhering to the surface of the semi-calcined hydrotalcite) is carried into the encapsulation layer, and over time, this moisture reaches the electronic device, becoming a factor in the degradation of the electronic device.

[0012] Therefore, it was found that simply increasing the amount of semi-calcined hydrotalcite used does not improve the sealing performance of the resin composition. Furthermore, the inventors' investigations revealed that even when the semi-calcined hydrotalcite was dried beforehand and incorporated into the resin composition, the above problem was not solved. This is presumed to be because, even after drying, the semi-calcined hydrotalcite quickly captures moisture from the air and returns to its original state. Therefore, it is necessary to dry the resin composition containing semi-calcined hydrotalcite and reduce the moisture content in the resin composition to below a certain level.

[0013] Even when the amount of semi-calcined hydrotalcite used is increased to improve moisture resistance, by sufficiently reducing the water content of the resin composition containing semi-calcined hydrotalcite, the degradation of electronic devices due to moisture introduced from the semi-calcined hydrotalcite into the resin composition can be sufficiently suppressed, and a resin composition with excellent sealing performance can be provided. Based on this finding, the present invention is characterized in that the water content of the resin composition is 2,500 ppm or less on a mass basis relative to the entire resin composition (the entire resin composition including volatile and non-volatile components). A lower water content is preferable (ideally 0 ppm), preferably 2,000 ppm or less, more preferably 1,500 ppm or less, even more preferably 1,000 ppm or less, and particularly preferably 800 ppm or less. This water content can be measured as described in the Examples section below.

[0014] A moisture content of 2,500 ppm or less can be achieved by appropriately setting the drying conditions of the resin composition. For example, when forming a resin composition layer by applying a resin composition varnish to a support and heating it, the heating temperature when forming the resin composition layer (i.e., the heating temperature of the coating film formed by applying the varnish) is preferably 70 to 150°C, and the heating time is preferably 10 minutes to 2 hours to form the resin composition layer. Then, by further drying the formed resin composition layer with a drying temperature (heating temperature) preferably 100 to 180°C and a drying time preferably 10 minutes to 7 weeks, the moisture content of the resin composition layer can be reduced to 2,500 ppm or less.

[0015] If the heating temperature for forming the resin composition layer and subsequent additional drying is low, it may take a long time to reduce the moisture content of the resin composition to 2,500 ppm or less, or it may be difficult to reduce it to 2,500 ppm or less. Therefore, it is preferable that the heating temperature for forming the resin composition layer and subsequent additional drying be relatively high. However, if the heating temperature is too high during the formation of the resin composition layer, problems such as air bubbles forming in the resin composition layer may occur. Therefore, it is preferable to set the formation temperature of the resin composition layer relatively low, and then set the temperature for subsequent additional drying of the resin composition layer higher than the formation temperature of the resin composition layer.

[0016] <Polyolefin resins> The polyolefin resins that can be used in the present invention are not particularly limited as long as they have an olefin-derived skeleton. For example, the polyolefin resin described in Patent Document 1 is a known example. The olefin is preferably a monoolefin having one olefinic carbon-carbon double bond and / or a diolefin having two olefinic carbon-carbon double bonds. Examples of monoolefins include α-olefins such as ethylene, propylene, 1-butene, isobutylene (isobutene), 1-pentene, 1-hexene, 1-heptene, and 1-octene, and examples of diolefins include 1,3-butadiene, isoprene, 1,3-pentadiene, and 2,3-dimethylbutadiene. The olefin-derived skeleton in the polyolefin resin may be one type or two or more types. The polyolefin resin may be used alone or two or more types may be used in combination.

[0017] Polyolefin resins may be homopolymers, random copolymers, block copolymers, or other types of copolymers. Examples of copolymers include copolymers of two or more olefins, and copolymers of olefins with non-olefin monomers such as non-conjugated dienes and styrene. Examples of preferred copolymers include ethylene-non-conjugated diene copolymers, ethylene-propylene copolymers, ethylene-propylene-non-conjugated diene copolymers, ethylene-butene copolymers, propylene-butene copolymers, propylene-butene-non-conjugated diene copolymers, styrene-isobutylene copolymers, and styrene-isobutylene-styrene copolymers.

[0018] Examples of polyolefin resins include isobutylene-modified resins described in International Publication No. 2011 / 62167 and styrene-isobutylene-modified resins described in International Publication No. 2013 / 108731.

[0019] Polyolefin resins are preferably polybutene resins or polypropylene resins. Here, "polybutene resin" refers to a resin in which the main unit (the unit with the highest content) of all olefin monomer units constituting the polymer is derived from butene, and "polypropylene resin" refers to a resin in which the main unit (the unit with the highest content) of all olefin monomer units constituting the polymer is derived from propylene.

[0020] Furthermore, when the polybutene resin is a copolymer, examples of monomers other than butene include styrene, ethylene, propylene, and isoprene. When the polypropylene resin is a copolymer, examples of monomers other than propylene include ethylene, butene, and isoprene.

[0021] From the viewpoint of imparting excellent physical properties such as adhesion and adhesive heat resistance, polyolefin resins preferably include polyolefin resins having acid anhydride groups (i.e., carbonyloxycarbonyl groups (-CO-O-CO-)) and / or polyolefin resins having epoxy groups. Examples of acid anhydride groups include groups derived from succinic anhydride, maleic anhydride, and glutaric anhydride. Polyolefin resins may have one or more acid anhydride groups. Polyolefin resins having acid anhydride groups can be obtained, for example, by graft modification of a polyolefin resin under radical reaction conditions using an unsaturated compound having acid anhydride groups. Alternatively, an unsaturated compound having acid anhydride groups may be radical copolymerized together with an olefin or the like. Similarly, polyolefin resins having epoxy groups can be obtained, for example, by graft modification of a polyolefin resin under radical reaction conditions using an unsaturated compound having epoxy groups such as glycidyl (meth)acrylate, 4-hydroxybutyl acrylate glycidyl ether, and allyl glycidyl ether. Furthermore, an unsaturated compound having an epoxy group may be radical copolymerized together with an olefin or the like. One or more polyolefin resins can be used, and a polyolefin resin having an acid anhydride group and a polyolefin resin having an epoxy group may be used in combination.

[0022] Preferred polyolefin resins having acid anhydride groups include polybutene resins having acid anhydride groups and polypropylene resins having acid anhydride groups. Furthermore, preferred polyolefin resins having epoxy groups include polybutene resins having epoxy groups and polypropylene resins having epoxy groups.

[0023] The concentration of acid anhydride groups in the polyolefin resin containing acid anhydride groups is preferably 0.05 to 10 mmol / g, and more preferably 0.1 to 5 mmol / g. The concentration of acid anhydride groups is obtained from the acid value, which is defined as the number of mg of potassium hydroxide required to neutralize the acid present in 1 g of resin, in accordance with JIS K 2501. Furthermore, the amount of polyolefin resin containing acid anhydride groups is preferably 0 to 70% by mass, more preferably 10 to 50% by mass.

[0024] Furthermore, the concentration of epoxy groups in the polyolefin resin having epoxy groups is preferably 0.05 to 10 mmol / g, and more preferably 0.1 to 5 mmol / g. The epoxy group concentration can be determined from the epoxy equivalent obtained based on JIS K 7236-1995. In addition, the amount of polyolefin resin having epoxy groups in the polyolefin resin is preferably 0 to 70% by mass, more preferably 10 to 50% by mass.

[0025] From the viewpoint of imparting excellent physical properties such as sealing performance, it is preferable that the polyolefin resin contains both a polyolefin resin having acid anhydride groups and a polyolefin resin having epoxy groups. In such a polyolefin resin, the acid anhydride groups and epoxy groups can react by heating to form a crosslinked structure, which can form a sealing layer with excellent sealing performance. Although the crosslinked structure can be formed after sealing, if the object to be sealed is sensitive to heat, such as an electronic device, it is desirable to seal it using a sealing film and to form the crosslinked structure when manufacturing the sealing film.

[0026] The ratio of polyolefin resin having acid anhydride groups to polyolefin resin having epoxy groups is not particularly limited as long as an appropriate crosslinking structure can be formed, but the molar ratio of epoxy groups to acid anhydride groups (epoxy groups: acid anhydride groups) is preferably 100:10 to 100:400, more preferably 100:25 to 100:350, and particularly preferably 100:40 to 100:300.

[0027] In the resin composition of the present invention, when a polyolefin resin having epoxy groups is used, a polyolefin resin having functional groups that can react with epoxy groups (excluding acid anhydride groups) may be used. Examples of such functional groups include hydroxyl groups, phenolic hydroxyl groups, amino groups, carboxyl groups, and the like.

[0028] In the resin composition of the present invention, when a polyolefin resin having an acid anhydride group is used, a polyolefin resin having a functional group (excluding epoxy group) that can react with the acid anhydride group may be used. Examples of such functional groups include hydroxyl groups, primary or secondary amino groups, thiol groups, and oxetane groups.

[0029] The number-average molecular weight of the 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, it is preferably 1,000,000 or less, more preferably 750,000 or less, even more preferably 500,000 or less, even more preferably 400,000 or less, even more preferably 300,000 or less, particularly preferably 200,000 or less, and most preferably 150,000 or less. On the other hand, from the viewpoint of preventing repulsion of the varnish of the resin composition during coating, exhibiting sealing performance of the formed resin composition layer, and improving mechanical strength, this number-average molecular weight is preferably 1,000 or more, and more preferably 2,000 or more. The number-average molecular weight in this invention is measured by gel permeation chromatography (GPC) (polystyrene equivalent). Specifically, the number-average molecular weight can be calculated using the GPC method by measuring with a Shimadzu LC-9A / RID-6A as the measuring instrument, a Showa Denko Shodex K-800P / K-804L / K-804L as the column, and toluene or the like as the mobile phase, at a column temperature of 40°C, and then using a calibration curve for standard polystyrene.

[0030] In the present invention, the polyolefin resin is preferably amorphous from the viewpoint of suppressing the decrease in fluidity due to the thickening of the varnish. Here, amorphous means that the polyolefin resin does not have a clear melting point, and for example, a polyolefin resin in which no clear peak is observed when the melting point is measured by DSC (Differential Scanning Calorimetry) can be used.

[0031] Next, specific examples of polyolefin resins will be explained. Specific examples of polypropylene resins include Seikoh PMC's "T-YP341" (glycidyl methacrylate-modified propylene-butene random copolymer, amount of butene units per 100% total mass of propylene and butene units: 29% by mass, epoxy group concentration: 0.638 mmol / g, number average molecular weight: 155,000), Seikoh PMC's "T-YP279" (maleic anhydride-modified propylene-butene random copolymer, amount of butene units per 100% total mass of propylene and butene units: 36% by mass, acid anhydride group concentration: 0.464 mmol / g, number average molecular weight: 35,000), and Seikoh PMC's "T-YP276" (glycidyl methacrylate-modified propylene-butene random copolymer, propylene units Examples include: (amount of butene units per 100% total mass of propylene and butene units: 36% by mass, epoxy group concentration: 0.638 mmol / g, number average molecular weight: 57,000), Seikoh PMC's "T-YP312" (maleic anhydride-modified propylene-butene random copolymer, amount of butene units per 100% total mass of propylene and butene units: 29% by mass, acid anhydride group concentration: 0.464 mmol / g, number average molecular weight: 60,900), and Seikoh PMC's "T-YP313" (glycidyl methacrylate-modified propylene-butene random copolymer, amount of butene units per 100% total mass of propylene and butene units: 29% by mass, epoxy group concentration: 0.638 mmol / g, number average molecular weight: 155,000).

[0032] Specific examples of polybutene-based resins include "HV-1900" (polybutene, number average molecular weight: 2,900) manufactured by ENEOS Corporation (formerly "JXTG Energy"), "HV-300M" (maleic anhydride-modified liquid polybutene (a modified version of "HV-300" (number average molecular weight: 1,400))) manufactured by Toho Chemical Industry Co., Ltd., number average molecular weight: 2,100, number of carboxyl groups constituting the acid anhydride group: 3.2 per molecule, acid value: 43.4 mg KOH / g, acid anhydride group concentration: 0.77 mmol / g), "Opanol B100" (polyisobutylene, viscosity average molecular weight: 1,110,000) and "N50SF" (polyisobutylene, viscosity average molecular weight: 400,000) manufactured by BASF.

[0033] Specific examples of styrene-isobutylene copolymers include Kaneka Corporation's "SIBSTAR T102" (styrene-isobutylene-styrene block copolymer, number average molecular weight: 100,000, styrene content: 30% by mass), Seikoh PMC's "T-YP757B" (maleic anhydride-modified styrene-isobutylene-styrene block copolymer, acid anhydride group concentration: 0.464 mmol / g, number average molecular weight: 100,000), and Seikoh PMC's "T-YP766" (glycidyl methacrylate-modified styrene-isobutylene-styrene block copolymer, epoxy Examples include "T-YP8920" (maleic anhydride-modified styrene-isobutylene-styrene copolymer, acid anhydride group concentration: 0.464 mmol / g, number average molecular weight: 35,800) manufactured by Seikoh PMC, with an epoxy group concentration of 0.638 mmol / g and a number average molecular weight of 100,000, and "T-YP8930" (glycidyl methacrylate-modified styrene-isobutylene-styrene copolymer, epoxy group concentration: 0.638 mmol / g, number average molecular weight: 48,700) manufactured by Seikoh PMC.

[0034] The content of the polyolefin resin in the resin composition of the present invention is not particularly limited. However, from the viewpoints of the sealing performance and handling properties of the resin composition, the content is preferably 5% by mass or more, more preferably 10% by mass or more, still more preferably 15% by mass or more, and preferably 50% by mass or less, more preferably 40% by mass or less, still more preferably 35% by mass or less, based on 100% by mass of the non-volatile content of the resin composition. <Compound ID: ><Compound ID:

[0035] ><Compound ID: ><Semifired hydrotalcite><Compound ID: >Hydrotalcite can be classified into unfired hydrotalcite, semifired hydrotalcite, and fired hydrotalcite. From the viewpoints of the transparency and moisture permeability resistance of the resin composition, semifired hydrotalcite is used in the present invention. <Compound ID: ><Compound ID:

[0036] ><Compound ID: >Unfired hydrotalcite is a metal hydroxide having a layered crystal structure represented by, for example, natural hydrotalcite (Mg6Al2(OH) <Compound ID: >CO3·4H2O), and is composed of, for example, a layer [Mg <Compound ID: 1-X >Al <Compound ID: X >(OH)2] <Compound ID: X+ >and an intermediate layer [(CO3) <Compound ID: X / 2 >·mH2O] <Compound ID: X- >. The unfired hydrotalcite in the present invention is a concept including hydrotalcite-like compounds such as synthetic hydrotalcite. Examples of the hydrotalcite-like compounds include those represented by the following formula (I) and the following formula (II). <Compound ID: ><Compound ID:

[0037] ><Compound ID: >[M <Compound ID: 2+ ><Compound ID: 1-x >M <Compound ID: 3+ ><Compound ID: x >(OH)2] <Compound ID: x+ >·[(A <Compound ID: n- >) <Compound ID: x / n >·mH2O] <Compound ID: x- ><Compound ID: >(I) <Compound ID: >(In the formula, M <Compound ID: 2+ >represents a divalent metal ion such as Mg <Compound ID: 2+ >, Zn <Compound ID: 2+ >, etc., and M <Compound ID: 3+ >represents Al <Compound ID: 3+ >, Fe3+ represents a trivalent metal ion such as A n- is CO3 2- , Cl - , NO3 - represents an n-valent anion such as, where 0 < x < 1, 0 ≦ m < 1, and n is a positive number.) In formula (I), M 2+ is preferably Mg 2+ and M 3+ is preferably Al 3+ and A n- is preferably CO3 2- .

[0038] M 2+ x Al2(OH) 2x+6-nz (A n- ) z ·mH2O (II) (In the formula, M 2+ represents a divalent metal ion such as Mg 2+ , Zn 2+ etc., A n- is CO3 2- , Cl - , NO3 - represents an n-valent anion such as, x is a positive number of 2 or more, z is a positive number of 2 or less, m is a positive number, and n is a positive number.)​​​​​​​​​​​​​​​​​On the other hand, calcined hydrotalcite refers to a metal oxide having an amorphous structure obtained by calcining uncalcined or semi-calcined hydrotalcite, in which not only intercalated water but also hydroxyl groups have disappeared through condensation dehydration.

[0041] Uncalcined hydrotalcite, semi-calcined hydrotalcite, and calcined hydrotalcite can be distinguished by their saturation water absorption rates. The saturation water absorption rate of semi-calcined hydrotalcite is 1% by mass or more and less than 20% by mass. On the other hand, the saturation water absorption rate of uncalcined hydrotalcite is less than 1% by mass, and the saturation water absorption rate of calcined hydrotalcite is 20% by mass or more.

[0042] In this invention, "saturation water absorption rate" refers to the rate of mass increase relative to the initial mass when 1.5 g of the sample (e.g., semi-calcined hydrotalcite) is weighed using a balance, its initial mass is measured, and then it is left standing for 200 hours in a small environmental test chamber (SH-222, manufactured by ESPEC Corporation) set to atmospheric pressure, 60°C, and 90% RH (relative humidity), as shown in the following formula (i): Saturated water absorption rate (mass%) = 100 × (mass after moisture absorption - initial mass) / initial mass (i) It can be calculated using this method.

[0043] The saturation water absorption rate of semi-calcined hydrotalcite is preferably 3% by mass or more and less than 20% by mass, more preferably 5% by mass or more and less than 20% by mass.

[0044] Furthermore, uncalcined hydrotalcite, semi-calcined hydrotalcite, and calcined hydrotalcite can be distinguished by their thermogravimetric analysis rates of thermal weight loss. Semi-calcined hydrotalcite has a thermal weight loss rate of less than 15% by mass at 280°C, and a thermal weight loss rate of 12% by mass or more at 380°C. On the other hand, uncalcined hydrotalcite has a thermal weight loss rate of 15% by mass or more at 280°C, while calcined hydrotalcite has a thermal weight loss rate of less than 12% by mass at 380°C.

[0045] Thermogravimetric analysis can be performed using a Hitachi High-Tech Science TG / DTA EXSTAR6300. 5 mg of hydrotalcite is weighed into an aluminum sample pan, and the pan is left open without a lid. The analysis is performed under a nitrogen flow rate of 200 mL / min, and the temperature is increased from 30°C to 550°C at a heating rate of 10°C / min. The thermogravimetric loss rate is calculated using the following formula (ii): Thermogravimetric reduction rate (mass%) = 100 × (mass before heating - mass when the predetermined temperature is reached) / mass before heating (ii) It can be calculated using this method.

[0046] Furthermore, uncalcined hydrotalcite, semi-calcined hydrotalcite, and calcined hydrotalcite can be distinguished by the peaks and relative intensity ratios measured by powder X-ray diffraction. Semi-calcined hydrotalcite shows a peak split into two around 8-18° 2θ by powder X-ray diffraction, or a peak with a shoulder formed by the combination of two peaks. The relative intensity ratio (low-angle diffraction intensity / high-angle diffraction intensity) of the diffraction intensity of the peak or shoulder appearing at the low angle (=low-angle diffraction intensity) to the diffraction intensity of the peak or shoulder appearing at the high angle (=high-angle diffraction intensity) is 0.001-1,000. On the other hand, uncalcined hydrotalcite has only one peak around 8-18°, or the relative intensity ratio of the diffraction intensity of the peak or shoulder appearing at the low angle to the peak or shoulder appearing at the high angle is outside the aforementioned range. Calcined hydrotalcite does not have a characteristic peak in the 8°-18° region, but has a characteristic peak at 43°. Powder X-ray diffraction measurements were performed using a powder X-ray diffractometer (PANalytical, Empyrean) under the following conditions: counter cathode CuKα (1.5405 Å), voltage: 45 V, current: 40 mA, sampling width: 0.0260°, scanning speed: 0.0657° / s, and measurement diffraction angle range (2θ): 5.0131~79.9711°. Peak search was performed using the peak search function of the software attached to the diffractometer, under the conditions of "minimum significance: 0.50, minimum peak tip: 0.01°, maximum peak tip: 1.00°, peak base width: 2.00°, method: minimum value of the second derivative".

[0047] The BET specific surface area of ​​both semi-calcined hydrotalcite and calcined hydrotalcite is 1 to 250 m². 2 / g is preferred, 5-200m 2 / g is more preferable. These BET specific surface areas can be calculated using the BET method by adsorbing nitrogen gas onto the sample surface using a specific surface area measuring device (Macsorb HM Model 1210, manufactured by Mountec) and then using the BET multipoint method.

[0048] The particle size of the semi-calcined hydrotalcite is preferably 1 to 1,000 nm, and more preferably 10 to 800 nm. These particle sizes are the median diameters of the particle size distribution when the particle size distribution is prepared on a volume basis by laser diffraction scattering particle size distribution measurement (JIS Z 8825).

[0049] Partially calcined hydrotalcite can be used after surface treatment with a surface treatment agent. Examples of surface treatment agents that can be used include higher fatty acids, alkylsilanes, and silane coupling agents, with higher fatty acids and alkylsilanes being particularly preferred. One or more surface treatment agents can be used.

[0050] Examples of higher fatty acids include those with 18 or more carbon atoms, such as stearic acid, montanic acid, myristic acid, and palmitic acid, with stearic acid being particularly preferred. One or more of these can be used.

[0051] Examples of alkylsilanes include methyltrimethoxysilane, ethyltrimethoxysilane, hexyltrimethoxysilane, octyltrimethoxysilane, decyltrimethoxysilane, octadecyltrimethoxysilane, dimethyldimethoxysilane, octyltriethoxysilane, and n-octadecyldimethyl(3-(trimethoxysilyl)propyl)ammonium chloride. One or more of these can be used.

[0052] Examples of silane coupling agents include epoxy-based silane coupling agents such as 3-glycidyloxypropyltrimethoxysilane, 3-glycidyloxypropyltriethoxysilane, 3-glycidyloxypropyl(dimethoxy)methylsilane, and 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane; 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-aminopropyltrimethoxysilane, N-methylaminopropyltrimethoxysilane, N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, and N-(2-aminoethyl)-3- Examples of silane coupling agents include amino-based silane coupling agents such as minopropyldimethoxymethylsilane; ureido-based silane coupling agents such as 3-ureidopropyltriethoxysilane; vinyl-based silane coupling agents such as vinyltrimethoxysilane, vinyltriethoxysilane, and vinylmethyldiethoxysilane; styryl-based silane coupling agents such as p-styryltrimethoxysilane; acrylate-based silane coupling agents such as 3-acrylooxypropyltrimethoxysilane and 3-methacryloxypropyltrimethoxysilane; isocyanate-based silane coupling agents such as 3-isocyanatetopropyltrimethoxysilane; sulfide-based silane coupling agents such as bis(triethoxysilylpropyl)disulfide and bis(triethoxysilylpropyl)tetrasulfide; and phenyltrimethoxysilane, methacryloxypropyltrimethoxysilane, imidazolesilane, triazinesilane, etc. One or more of these can be used.

[0053] Surface treatment of semi-calcined hydrotalcite, etc., can be performed, for example, by adding and spraying a surface treatment agent while stirring and dispersing untreated semi-calcined hydrotalcite, etc., at room temperature in a mixer, and stirring for 5 to 60 minutes. As a mixer, known mixers can be used, such as blenders such as V blenders, ribbon blenders, and bubble cone blenders, mixers such as Henschel mixers and concrete mixers, ball mills, cutter mills, etc. Surface treatment can also be performed by adding the above-mentioned higher fatty acids, alkylsilanes, or silane coupling agents when crushing hydrotalcite with a ball mill, etc. The amount of surface treatment agent used varies depending on the type of hydrotalcite or the type of surface treatment agent, etc., but 1 to 10 parts by mass per 100 parts by mass of untreated hydrotalcite is preferred. In the present invention, surface-treated semi-calcined hydrotalcite is included in the concept of "semi-calcined hydrotalcite" in the present invention.

[0054] The content of semi-calcined hydrotalcite in the resin composition of the present invention is more than 45% by mass relative to 100% by mass of the non-volatile content of the resin composition, from the viewpoint of exhibiting the sealing performance of the resin composition of the present invention. This content is preferably 50% by mass or more, more preferably 55% by mass or more, and even more preferably 60% by mass or more. Furthermore, there is no particular upper limit to this content as long as the effects of the present invention are exhibited, but from the viewpoint of transparency of the resin composition, this content is preferably 80% by mass or less, more preferably 75% by mass or less, and even more preferably 70% by mass or less.

[0055] The resin composition of the present invention may contain fillers other than semi-calcined hydrotalcite, to the extent that the effects of the present invention are not impaired. Examples of fillers other than semi-calcined hydrotalcite include inorganic fillers such as silica, alumina, barium sulfate, aluminum hydroxide, magnesium hydroxide, calcium carbonate, magnesium carbonate, boron nitride, aluminum borate, barium titanate, strontium titanate, calcium titanate, magnesium titanate, bismuth titanate, titanium oxide, zirconium oxide, barium zirconate, calcium zirconate, and silicates, as well as organic fillers such as rubber particles, silicone powder, nylon powder, and fluororesin powder. The content of fillers other than semi-calcined hydrotalcite is preferably 50 parts by mass or less, more preferably 30 parts by mass or less, even more preferably 20 parts by mass or less, and even more preferably 10 parts by mass or less, based on the content of semi-calcined hydrotalcite per 100 parts by mass.

[0056] <Adhesion agent> The resin composition of the present invention may further contain a tackifier. The tackifier, also called a tackifier, is a component that imparts tackiness to the composition. The tackifier is not particularly limited, but terpene resins, modified terpene resins (hydrogenated terpene resins, terpene phenol copolymer resins, aromatically modified terpene resins, etc.), coumarone resins, indene resins, and petroleum resins (aliphatic petroleum resins, hydrogenated alicyclic petroleum resins, aromatic petroleum resins, aliphatic aromatic copolymer petroleum resins, alicyclic petroleum resins, dicyclopentadiene petroleum resins and their hydrides, etc.) are preferably used.

[0057] Examples of commercially available products that can be used as tackifiers include the following: Terpene resins such as YS Resin PX and YS Resin PXN (both manufactured by Yasuhara Chemical Co., Ltd.), aromatic modified terpene resins such as YS Resin TO and TR series (both manufactured by Yasuhara Chemical Co., Ltd.), hydrogenated terpene resins such as Clearon P, Clearon M and Clearon K series (all manufactured by Yasuhara Chemical Co., Ltd.), terpene phenol copolymer resins such as YS Polystar 2000, Polystar U, Polystar T, Polystar S and Mighty Ace G (all manufactured by Yasuhara Chemical Co., Ltd.), and hydrogenated alicyclic petroleum resins. Examples of these include the Escorez 5300 series and 5600 series (both manufactured by ExxonMobil), as well as aromatic petroleum resins such as ENDEX 155 (manufactured by Eastman), as aliphatic aromatic copolymer petroleum resins such as Quintone D100 (manufactured by Nippon Zeon Co., Ltd.), as alicyclic petroleum resins such as Quintone 1325 and Quintone 1345 (both manufactured by Nippon Zeon Co., Ltd.), and as saturated hydrocarbon resins such as Alcon P100, Alcon P125, Alcon P140, and TFS13-030 (all manufactured by Arakawa Chemical Corporation).

[0058] The softening point of the tackifier is preferably 50 to 200°C, more preferably 90 to 180°C, and even more preferably 100 to 150°C, from the viewpoint of allowing the resin composition sheet to soften during the lamination process while maintaining the desired heat resistance. The softening point is measured by the ring-and-ball method in accordance with JIS K2207.

[0059] One or more types of tackifiers may be used in combination. There are no particular restrictions on the content of tackifiers in the resin composition. However, from the viewpoint of maintaining good sealing performance of the resin composition, when a tackifier is used, its content is preferably 50% by mass or less, more preferably 40% by mass or less, and even more preferably 30% by mass or less, based on 100% by mass of the nonvolatile content of the resin composition. On the other hand, from the viewpoint of having sufficient adhesion, when a tackifier is used, its content is preferably 5% by mass or more, and even more preferably 10% by mass or more, based on 100% by mass of the nonvolatile content of the resin composition.

[0060] From the viewpoint of adhesion, sealing performance, and transparency of the resin composition, petroleum resins are preferred. Examples of petroleum resins include aliphatic petroleum resins, aromatic petroleum resins, aliphatic aromatic copolymer petroleum resins, and alicyclic petroleum resins. From the viewpoint of adhesion, sealing performance, and compatibility of the resin composition, aromatic petroleum resins, aliphatic aromatic copolymer petroleum resins, and alicyclic petroleum resins are more preferred. Furthermore, from the viewpoint of improving transparency, alicyclic petroleum resins are particularly preferred. Alicyclic petroleum resins can also be obtained by hydrogenating aromatic petroleum resins. In this case, the hydrogenation rate of the alicyclic petroleum resin is preferably 30-99%, more preferably 40-97%, and even more preferably 50-90%. If the hydrogenation rate is too low, there is a tendency for the transparency to decrease due to coloration, and if the hydrogenation rate is too high, there is a tendency for production costs to increase. The hydrogenation rate is the difference between the hydrogen of the aromatic ring before hydrogenation and after hydrogenation. 1 This can be determined from the ratio of peak intensities of 1H-NMR. Among alicyclic petroleum resins, cyclohexane ring-containing hydrogenated petroleum resins and dicyclopentadiene-based hydrogenated petroleum resins are particularly preferred. One or more types of petroleum resins may be used in combination. The number-average molecular weight Mn of the petroleum resin is preferably 100 to 2,000, more preferably 700 to 1,500, and even more preferably 500 to 1,000.

[0061] <Hardening agent and / or curing accelerator> The resin composition of the present invention may contain a curing agent and / or a curing accelerator (preferably a curing accelerator). Both the curing agent and the curing accelerator may be used individually or in combination of two or more. Examples of curing agents include imidazole compounds, tertiary and quaternary amine compounds, dimethylurea compounds, organophosphine compounds, and primary and secondary amine compounds. Examples of curing accelerators include imidazole compounds, tertiary and quaternary amine compounds, dimethylurea compounds, and organophosphine compounds.

[0062] Examples of imidazole compounds that serve as curing agents and / or curing accelerators in the present invention include 1H-imidazole, 2-methylimidazole, 2-phenyl-4-methylimidazole, 2-ethyl-4-methylimidazole, 1-cyanoethyl-2-ethyl-4-methylimidazole, 2-undecylimidazole, 1-cyanoethyl-2-undecylimidazole, 1-cyanoethyl-2-undecylimidazolium trimellitate, 2,4-diamino-6-(2'-undecylimidazolyl-(1'))-ethyl-s-triazine, 2-phenyl-4,5-bis(hydroxymethyl)imidazole, 1-benzyl-2-methylimidazole, 1-benzyl-2-phenylimidazole, 2-phenylimidazole, 2- Examples include decylimidazole, 2-heptadecylimidazole, 1,2-dimethylimidazole, 2-phenyl-4-methyl-5-hydroxymethylimidazole, 2,4-diamino-6-(2'-methylimidazolyl-(1'))-ethyl-s-triazine, and 2,4-diamino-6-(2'-methylimidazolyl-(1'))-ethyl-s-triazine isocyanuric acid adducts. Specific examples of imidazole compounds include Curesol 2MZ, 2P4MZ, 2E4MZ, 2E4MZ-CN, C11Z, C11Z-CN, C11Z-CNS, C11Z-A, 2PHZ, 1B2MZ, 1B2PZ, 2PZ, C17Z, 1.2DMZ, 2P4MHZ-PW, 2MZ-A, and 2MA-OK (all manufactured by Shikoku Chemicals Co., Ltd.).

[0063] There are no particular limitations on the tertiary or quaternary amine compounds used as curing agents and / or curing accelerators in the present invention, but examples include quaternary ammonium salts such as tetramethylammonium bromide and tetrabutylammonium bromide; diazabicyclo compounds such as 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, and DBU-phenol novolac resin salt; tertiary amines such as benzyldimethylamine, 2-(dimethylaminomethyl)phenol, and 2,4,6-tris(dimethylaminomethyl)phenol (TAP) and their salts, and dimethylurea compounds such as aromatic dimethylurea and aliphatic dimethylurea.

[0064] Examples of primary and secondary amine compounds used as curing agents in the present invention include aliphatic amines such as diethylenetriamine, triethylenetetraamine, tetraethylenepentamine, trimethylhexamethylenediamine, 2-methylpentamethylenediamine, 1,3-bisaminomethylcyclohexane, dipropylenediamine, diethylaminopropylamine, bis(4-aminocyclohexyl)methane, norbornenediamine, and 1,2-diaminocyclohexane; alicyclic amines such as N-aminoethylpiberazine and 1,4-bis(3-aminopropyl)piperazine; and aromatic amines such as diaminodiphenylmethane, m-phenylenediamine, m-xylenediamine, metaphenylenediamine, diaminodiphenylmethane, diaminodiphenylsulfone, and diethyltoluenediamine. Specific examples of primary and secondary amine compounds include Kayahard AA (manufactured by Nippon Kayaku Co., Ltd.: 4,4'-diamino-3,3'-dimethyldiphenylmethane).

[0065] Specific examples of dimethylurea compounds used as curing agents and / or curing accelerators in the present invention include aromatic dimethylureas such as DCMU (3-(3,4-dichlorophenyl)-1,1-dimethylurea) and U-CAT3512T (manufactured by Sunapro Co., Ltd.), and aliphatic dimethylureas such as U-CAT3503N (manufactured by Sunapro Co., Ltd.). Among these, aromatic dimethylureas are preferred in terms of curability.

[0066] Examples of organic phosphine compounds used as curing agents and / or curing accelerators in the present invention include triphenylphosphine, tetraphenylphosphonium tetra-p-tolylborate, tetraphenylphosphonium tetraphenylborate, tri-tert-butylphosphonium tetraphenylborate, (4-methylphenyl)triphenylphosphonium thiocyanate, tetraphenylphosphonium thiocyanate, butyltriphenylphosphonium thiocyanate, triphenylphosphinetriphenylborane, and the like. Specific examples of organic phosphine compounds include TPP, TPP-MK, TPP-K, TTBuP-K, TPP-SCN, and TPP-S (manufactured by Hokko Chemical Industry Co., Ltd.).

[0067] There are no particular restrictions on the total content of curing agent and curing accelerator in the resin composition, but from the viewpoint of preventing a decrease in the transparency of the sealing layer (resin composition layer), it is preferable that the total content be 5% by mass or less, and more preferably 1% by mass or less, based on 100% by mass of the nonvolatile content of the resin composition. On the other hand, from the viewpoint of suppressing the tack of the sealing layer, the total content is preferably 0.0005% by mass or more, and more preferably 0.001% by mass or more, based on 100% by mass of the nonvolatile content of the resin composition.

[0068] There are no particular restrictions on the content of the curing accelerator in the resin composition, but from the viewpoint of preventing a decrease in the transparency of the sealing layer (resin composition layer), it is preferable that the content be 5% by mass or less, and more preferably 1% by mass or less, based on 100% by mass of the nonvolatile content of the resin composition. On the other hand, from the viewpoint of suppressing the tack of the sealing layer, the content is preferably 0.0005% by mass or more, and more preferably 0.001% by mass or more, based on 100% by mass of the nonvolatile content of the resin composition.

[0069] <Plasticizer> The resin composition of the present invention may further contain a plasticizer. By using a plasticizer, the flexibility and moldability of the resin composition can be improved. The plasticizer is not particularly limited, but a material that is liquid at room temperature is preferably used. Specific examples of plasticizers include paraffinic process oils, naphthenic process oils, liquid paraffin, polyethylene wax, polypropylene wax, mineral oils such as petrolatum, vegetable oils such as castor oil, cottonseed oil, rapeseed oil, soybean oil, palm oil, coconut oil, and olive oil, and liquid poly-α-olefins such as liquid polybutene, hydrogenated liquid polybutene, liquid polybutadiene, and hydrogenated liquid polybutadiene. Liquid poly-α-olefins are preferred as plasticizers used in the present invention, and liquid polybutadiene is particularly preferred. Furthermore, as liquid poly-α-olefins, those with a low molecular weight are preferred from the viewpoint of adhesion, and those with a weight-average molecular weight in the range of 500 to 5,000, and more preferably in the range of 1,000 to 3,000, are preferred. These plasticizers may be used individually or in combination of two or more. Here, "liquid" refers to the state of the plasticizer at room temperature (25°C). When using plasticizers, from the viewpoint of not adversely affecting electronic devices, their content is preferably 50% by mass or less relative to 100% by mass of the non-volatile content of the resin composition.

[0070] <Other ingredients> The resin composition of the present invention may optionally contain components other than those described above, to the extent that they do not impair the effects of the present invention. Examples of such components include resins other than the polyolefin resins described above (e.g., epoxy resins, urethane resins, acrylic resins, polyamide resins, etc.); thickeners such as olbene and benton; silicone-based, fluorine-based, or polymer-based defoaming or leveling agents; adhesion-improving agents such as triazole compounds, thiazole compounds, triazine compounds, and porphyrin compounds; and the like.

[0071] <Method for producing resin compositions> The method for producing the resin composition of the present invention is not particularly limited, as long as the water content can be sufficiently reduced. For example, a resin composition with reduced water content can be produced by mixing each component and, if necessary, a solvent, and then drying the resulting mixture.

[0072] Drying the mixture is most easily done by heating. Heating may be carried out under normal pressure or under reduced pressure. The heating temperature and heating time may vary depending on the components used. A person skilled in the art can appropriately set the heating temperature and heating time to sufficiently reduce the moisture content, depending on the components used.

[0073] <Resin sheet and method for manufacturing the same> The present invention also provides a resin sheet having a support and a layer of the resin composition of the present invention provided on the support (hereinafter sometimes abbreviated as "resin composition layer").

[0074] The resin composition layer of the resin sheet can be formed by a method known to those skilled in the art. For example, it can be formed by preparing a varnish by dissolving the above-mentioned components in an organic solvent, and then applying and drying the varnish on a support. The non-volatile content of the varnish is preferably 20 to 80% by mass, more preferably 30 to 70% by mass.

[0075] Examples of organic solvents include ketones such as acetone, methyl ethyl ketone (MEK), and cyclohexanone; acetic acid esters such as ethyl acetate, butyl acetate, cellosolve acetate, propylene glycol monomethyl ether acetate, and carbitol acetate; cellosolves such as cellosolve; carbitols such as butyl carbitol; aromatic hydrocarbons such as toluene and xylene; dimethylformamide, dimethylacetamide, and N-methylpyrrolidone. Only one organic solvent may be used, or two or more may be used in combination.

[0076] Drying the varnish is most easily done by heating. Heating may be carried out under normal pressure or under reduced pressure. The heating temperature and heating time may vary depending on the components and organic solvents used. The heating temperature and heating time required to sufficiently reduce the water content can be appropriately set by those skilled in the art, depending on the components and organic solvents used. Furthermore, the preferred conditions for reducing the water content of the resin composition layer to 2,500 ppm or less are as described above.

[0077] When preparing a resin sheet using a resin composition containing a polyolefin resin having acid anhydride groups and a polyolefin resin having epoxy groups, reacting the acid anhydride groups with the epoxy groups to form a crosslinked structure increases the moisture permeability resistance of the resin composition layer, resulting in a resin sheet with higher sealing performance (such as the ability to block moisture and oxygen from the air).

[0078] The thickness of the resin composition layer in the resin sheet is preferably 1 to 1000 μm, more preferably 2 to 800 μm.

[0079] Examples of supports used for resin sheets include polyolefins such as polyethylene, polypropylene, and polyvinyl chloride; cycloolefin polymers; polyesters such as polyethylene terephthalate (hereinafter sometimes abbreviated as "PET") and polyethylene naphthalate; polycarbonate; and plastic films such as polyimide. The surface of the support that is joined to the resin composition layer may be treated with a release agent. Examples of release agents include silicone resin-based release agents, alkyd resin-based release agents, and fluororesin-based release agents.

[0080] The thickness of the support is not particularly limited, but from the viewpoint of handling the resin sheet, 10 to 150 μm is preferred, and 20 to 100 μm is more preferred.

[0081] A support having a barrier layer (for example, a plastic film having a barrier layer) is preferred for use with the resin sheet. Examples of the barrier layer include inorganic films such as silica vapor-deposited films, silicon nitride films, and silicon oxide films. The barrier layer may consist of multiple layers of multiple inorganic films (for example, silica vapor-deposited films). The barrier layer may also consist of organic and inorganic materials, or it may be a composite multilayer of an organic layer and an inorganic film.

[0082] Examples of supports having a barrier layer include those with a water vapor transmission rate (WVTR) of 0.0005 g / m³. 2High-barrier plastic films with a barrier life of 0.5 / 24hr or less can be used. Examples of high-barrier plastic films include those manufactured by laminating inorganic films such as silicon dioxide (silica), aluminum oxide, magnesium oxide, silicon nitride, silicon oxide nitride, SiCN, and amorphous silicon on the surface of a plastic film in single or multi-layer forms using chemical vapor deposition (e.g., chemical vapor deposition using heat, plasma, ultraviolet light, vacuum heat, vacuum plasma, or vacuum ultraviolet light) or physical vapor deposition (e.g., vacuum deposition, sputtering, ion plating, laser deposition, molecular beam epitaxy) (see, for example, Japanese Patent Publication No. 2016-185705, Japanese Patent No. 5719106, Japanese Patent No. 5712509, Japanese Patent No. 5292358, etc.). To prevent cracking of the inorganic film, it is preferable to alternately laminate the inorganic film and a transparent planarization layer (e.g., a transparent plastic layer).

[0083] Furthermore, as a support having a barrier layer, for example, if the WVTR is 0.01 (g / m²) 2 / 24hr) or more 1(g / m 2 A medium-barrier plastic film with a barrier life of 24 hours or less can be used. Examples of medium-barrier plastic films include those manufactured by methods such as depositing an inorganic film containing inorganic substances such as silicon dioxide (silica), aluminum oxide, magnesium oxide, silicon nitride, silicon oxide nitride, SiCN, and amorphous silicon onto the substrate surface as a barrier layer, or by applying a coating liquid consisting of a metal oxide and an organic resin having barrier properties to the substrate and drying it (see, for example, Japanese Patent Publication No. 2013-108103 and Japanese Patent No. 4028353).

[0084] Water vapor transmission rate can be measured as follows. First, a test specimen is prepared by punching out a 60 mm diameter piece from a plastic film with a barrier layer. According to JIS Z 0208:1976, the transmission area is 2.826 × 10⁻⁶. -3 m 27.5g of calcium chloride is weighed into an aluminum moisture-permeable cup (60mmφ) and the test specimen is placed inside. The initial mass of the moisture-permeable cup with the calcium chloride and test specimen is measured using a precision balance. Next, the moisture-permeable cup is left to stand for 24 hours in a constant temperature test chamber at 40°C and 90%RH humidity. After that, the mass of the moisture-permeable cup with the calcium chloride and test specimen is measured using a precision balance. The mass increase (=mass after moisture permeation - initial mass) is taken as the amount of water vapor transmitted, and the water vapor transmission rate (g / m³) is calculated from the amount of water vapor transmitted, the permeation area, and the standing time. 2 Calculate ( / 24hr).

[0085] Commercially available products may be used as the support having a barrier layer. Examples of commercially available medium-barrier plastic films include "Clarista CI" from Kuraray, "Tech Barrier HX," "Tech Barrier LX," and "Tech Barrier L" from Mitsubishi Plastics, Inc., "IB-PET-PXB" from Dai Nippon Printing Co., Ltd., and the "GL, GX series" from Toppan Printing Co., Ltd. Examples of commercially available high-barrier plastic films include "X-BARRIER" from Mitsubishi Plastics, Inc.

[0086] It is preferable to protect the resin composition layer provided on the support with a protective film. Lamination of the protective film onto the resin composition layer can be carried out using known equipment. Examples of equipment used for laminating the protective film include a roll laminator, a press, and a vacuum pressure laminator.

[0087] Examples of protective films include the aforementioned plastic films. It is preferable that the surface of the protective film that adheres to the resin composition layer is treated with a release agent. Examples of release agents include silicone resin-based release agents, alkyd resin-based release agents, and fluororesin-based release agents.

[0088] The thickness of the protective film is not particularly limited, but from the viewpoint of handling the resin sheet, 10 to 150 μm is preferred, and 20 to 100 μm is more preferred.

[0089] It is preferable to use a protective film having a barrier layer to suppress the absorption of moisture by the resin composition layer after drying. Examples of protective films having a barrier layer include the aforementioned plastic film having a barrier layer. From the viewpoint of cost and other factors, it is preferable to use the aforementioned medium-barrier plastic film for the protective film.

[0090] <Application> The resin composition and resin sheet of the present invention can be used for encapsulating electronic devices. More preferably, the electronic device is an electronic device that is sensitive to moisture, such as an organic EL device or a solar cell. In other words, the resin composition and resin sheet of the present invention can be suitably used for encapsulating electronic devices that are sensitive to moisture, such as organic EL devices and solar cells. [Examples]

[0091] The present invention will be described in more detail below with reference to examples, but the present invention is not limited by the following examples, and it is possible to implement it with appropriate modifications within the scope that is consistent with the spirit of the above and below, and all such modifications are included in the technical scope of the present invention. In addition, unless otherwise specified, "parts" and "%" in the amounts of components and copolymer units mean "parts by mass" and "mass%", respectively.

[0092] <Ingredients> The components used in the examples and comparative examples are shown below. (Polyolefin resin) "HV-1900" (manufactured by JXTG Energy Corporation): Polybutene, number average molecular weight 2,900 "HV-300M" (manufactured by Toho Chemical Industry Co., Ltd.): Maleic anhydride-modified liquid polybutene, acid anhydride group concentration 0.77 mmol / g, number average molecular weight 2,100 "T-YP341" (manufactured by Seikoh PMC): Glycidyl methacrylate-modified propylene-butene random copolymer, propylene units / butene units 71% / 29%, epoxy group concentration 0.638 mmol / g, number average molecular weight 155,000 (Partially calcined hydrotalcite) "DHT-4C" (manufactured by Kyowa Chemical Industry Co., Ltd.): Semi-calcined hydrotalcite, average particle size 400 nm, BET specific surface area 15 m² 2 / g (Adhesion agent) "Alcon P125" (manufactured by Arakawa Chemical Co., Ltd.): Cyclohexane ring-containing saturated hydrocarbon resin, softening point 125°C (Curing accelerator) 2,4,6-Tris(dimethylaminomethyl)phenol (hereinafter abbreviated as "TAP") (manufactured by Kayaku Akzo): Curing accelerator

[0093] <Example 1> Varnishes with the mixing ratios shown in the table below were prepared using the following procedure, and resin sheets were made using the obtained varnishes. The amount (parts) of each component listed in the table below indicates the amount of non-volatile content of each component in the varnish. The table below also shows the content of semi-calcined hydrotalcite used as semi-calcined hydrotalcite relative to 100% by mass of the non-volatile content of the resin composition.

[0094] Specifically, a mixture was obtained by dispersing maleic anhydride-modified liquid polybutene (HV-300M, Toho Chemical Industries), polybutene (HV-1900, JXTG Energy Corporation), and semi-calcined hydrotalcite (DHT-4C, Kyowa Chemical Industries) in a three-roll mixer in a Swazole solution (60% non-volatile content) of a cyclohexane ring-containing saturated hydrocarbon resin (tackifier; Alcon P125, Arakawa Chemical Co., Ltd.). To the obtained mixture, a Swazole solution (20% non-volatile content) of glycidyl methacrylate-modified propylene-butene random copolymer (T-YP341, Seikoh PMC), a curing accelerator (TAP, Kayaku Akzo), and toluene were added, and the resulting mixture was uniformly dispersed in a high-speed rotary mixer to obtain a resin composition varnish. The obtained varnish was uniformly applied using a die coater to the release-treated surface of a polyethylene terephthalate (PET) film "SP4020" (PET: 50 μm: manufactured by Toyo Cloth Co., Ltd.) that had been treated with a silicone-based release agent. The film was then heated at 130°C for 30 minutes, followed by heating at 160°C for another 30 minutes to obtain a resin sheet having a resin composition layer with a thickness of 25 μm.

[0095] <Example 2> A resin sheet having a resin composition varnish and a resin composition layer with a thickness of 25 μm was prepared in the same manner as in Example 1, except that the amount of semi-calcined hydrotalcite (DHT-4C, manufactured by Kyowa Chemical Industry Co., Ltd.) used was changed from 300 parts to 250 parts.

[0096] <Example 3> A resin sheet having a resin composition varnish and a resin composition layer with a thickness of 25 μm was prepared in the same manner as in Example 1, except that the amount of semi-calcined hydrotalcite (DHT-4C, manufactured by Kyowa Chemical Industry Co., Ltd.) used was changed from 300 parts to 200 parts.

[0097] <Example 4> A resin sheet having a resin composition varnish and a resin composition layer with a thickness of 25 μm was prepared using the same method as in Example 1, except that the amount of semi-calcined hydrotalcite (DHT-4C, manufactured by Kyowa Chemical Industry Co., Ltd.) used was changed from 300 parts to 100 parts.

[0098] <Comparative Example 1> Varnishes with the mixing ratios shown in the table below were prepared using the following procedure, and resin sheets were made using the obtained varnishes. The amount (parts) of each component listed in the table below indicates the amount of non-volatile content of each component in the varnish. The table below also shows the content of semi-calcined hydrotalcite relative to 100% by mass of the non-volatile content of the resin composition.

[0099] Specifically, a mixture was obtained by dispersing maleic anhydride-modified liquid polybutene (HV-300M, Toho Chemical Industries), polybutene (HV-1900, JXTG Energy Corporation), and semi-calcined hydrotalcite (DHT-4C, Kyowa Chemical Industries) in a three-roll mixer in a Swazole solution (60% non-volatile content) of a cyclohexane ring-containing saturated hydrocarbon resin (tackifier; Alcon P125, Arakawa Chemical Co., Ltd.). To the obtained mixture, a Swazole solution (20% non-volatile content) of glycidyl methacrylate-modified propylene-butene random copolymer (T-YP341, Seikoh PMC), a curing accelerator (TAP, Kayaku Akzo), and toluene were added, and the resulting mixture was uniformly dispersed in a high-speed rotary mixer to obtain a resin composition varnish. The obtained varnish was uniformly applied using a die coater to the release-treated surface of a PET film "SP4020" (PET: 50 μm: manufactured by Toyo Cloth Co., Ltd.) that had been treated with a silicone-based release agent. The film was then heated at 130°C for 30 minutes, followed by heating at 160°C for 15 minutes to obtain a resin sheet having a resin composition layer with a thickness of 25 μm.

[0100] <Comparative Example 2> A varnish of the resin composition was prepared in the same manner as in Example 1. The obtained varnish was uniformly applied to the release-treated surface of a PET film "SP4020" (PET: 50 μm: manufactured by Toyo Cloth Co., Ltd.) treated with a silicone-based release agent using a die coater, and heated at 130°C for 30 minutes to obtain a resin sheet having a resin composition layer with a thickness of 25 μm.

[0101] <Comparative Example 3> A resin composition varnish was prepared in the same manner as in Example 4. The obtained varnish was uniformly applied to the release-treated surface of a PET film "SP4020" (PET: 50 μm: manufactured by Toyo Cloth Co., Ltd.) treated with a silicone-based release agent using a die coater, and heated at 130°C for 60 minutes to obtain a resin sheet having a resin composition layer with a thickness of 25 μm.

[0102] <Comparative Example 4> A resin sheet having a resin composition layer with a thickness of 25 μm was prepared using the same method as in Comparative Example 3, except that the varnish was prepared with the mixing ratio of Comparative Example 4 shown in Table 1 below.

[0103] For the resin composition layers of each resin sheet obtained in the examples and comparative examples, transparency was evaluated by total light transmittance, moisture permeability (sealing performance) by average moisture penetration distance, and suppression of deterioration of the sealed area due to internal moisture (sealing performance) by reflectance ratio.

[0104] <Moisture content of the resin composition layer> The resin sheets prepared in the examples and comparative examples were cut to a length of 70 mm and a width of 40 mm. The support (i.e., PET film "SP4020" treated with a silicone-based release agent) was peeled off, and the resin composition layer was folded and placed in a well-dried screw vial (VABH17, manufactured by Mitsubishi Chemical Analytec Co., Ltd.). The vial was then placed in an electric furnace (VA-236S, manufactured by Mitsubishi Chemical Analytec Co., Ltd.) directly connected to a Karl Fischer measuring instrument (CA310, manufactured by Mitsubishi Chemical Analytec Co., Ltd.). The temperature of the electric furnace was raised to 250°C in an N2 airflow, and the water detached from the sample was collected in a Karl Fischer measuring solution. The mass of the water was measured using a standard method. From the measured mass of water, the water content (ppm) of the resin composition layer was calculated on a mass basis relative to the entire resin composition. The results are shown in the table below.

[0105] <Total light transmittance> The resin sheets prepared in the examples and comparative examples were cut to a length of 50 mm and a width of 20 mm, and the cut resin sheets were placed on a glass plate (a micro-slide glass with a length of 76 mm, a width of 26 mm, and a thickness of 1.2 mm (Matsunami Glass Industry Co., Ltd. white slide glass S1112)). A batch-type vacuum laminator (Nichigo Morton, V-160) was used to laminate the resin composition layer to the glass plate, ensuring contact between the layer and the glass plate. The lamination conditions were a temperature of 80°C, a depressurization time of 30 seconds, followed by pressurization at 0.3 MPa for 30 seconds. Subsequently, the PET film of the resin sheet was peeled off, and the light transmittance spectrum of the exposed resin composition layer was measured using a fiber optic spectrophotometer (MCPD-7700, model 311C, Otsuka Electronics, external light source unit: halogen lamp MC-2564 (24V, 150W specification)) equipped with a φ60 mm integrating sphere (model SRS-99-010, reflectance 99%). The total light transmittance (%) at a wavelength of 450 nm was calculated and evaluated according to the following criteria. The results are shown in the table below. The distance between the integrating sphere and the sample (laminate) was set to 0 mm, and glass was used as the reference. Good (○): Total light transmittance is 90% or higher. Defective (×): Total light transmittance is less than 90%

[0106] <Average moisture penetration distance> A 50mm x 50mm square piece of alkali-free glass was washed with boiled isopropyl alcohol for 5 minutes and dried at 150°C for at least 30 minutes. Next, the alkali-free glass was washed with UV ozone. Using a mask positioned 2mm from the edges, a calcium film (99.8% purity) was deposited onto the washed alkali-free glass (thickness 200nm).

[0107] A resin sheet having a laminated structure of PET / aluminum foil / resin composition layer having the same resin composition layer as in each example and comparative example was obtained in the same manner as in each example and comparative example, except that an aluminum foil / PET composite film "PET-Tsuki AL1N30" (aluminum foil: 30 μm, PET: 25 μm, manufactured by Tokai Toyo Aluminum Sales Co., Ltd.) was used as the support.

[0108] A sample for evaluation was obtained by laminating alkali-free glass coated with a calcium film using a thermal laminator (Fujiplas Corporation, Lamipacker DAiSY A4 (LPD2325)) inside a glove box, so that the calcium film and the resin composition layer were in contact.

[0109] When calcium comes into contact with water, it becomes calcium oxide, which turns transparent. Therefore, the penetration of water into the evaluation sample can be evaluated by measuring the distance (mm) from the edge of the evaluation sample to the calcium film.

[0110] The distance from the edge of the evaluation sample obtained as described above to the calcium film was measured at eight points using a Mitutoyo Measuring Microscope MF-U, and the average value was defined as X2.

[0111] Next, the evaluation samples were placed in a constant temperature and humidity chamber set to 85°C and 85% RH relative humidity. After 40 hours in the chamber, the distance from the edge of the evaluation sample to the calcium film was measured at eight points, and the average value was defined as X1 (mm).

[0112] From the obtained X1 and X2, the average moisture penetration distance X (=X1 - X2) into the calcium membrane after immersion in a constant temperature and humidity chamber was calculated, and the moisture resistance of the resin composition layer under high temperature and high humidity conditions was evaluated according to the following criteria. The higher the moisture resistance, the slower the rate of moisture penetration, and the smaller the value of the average moisture penetration distance X. The results are shown in the table below. Note that if X is less than 0.1 mm, it is indicated as "<0.1" in the table below. Furthermore, for Comparative Examples 3 and 4, where X1 could not be measured due to deterioration of the calcium membrane due to moisture, the results were evaluated as poor (×). Good (○): X is less than 1mm Defective (×): X is 1 mm or larger, or X1 cannot be measured due to deterioration of the calcium film caused by moisture.

[0113] <Reflectance ratio> A 50mm x 50mm square piece of alkali-free glass was washed with boiled isopropyl alcohol for 5 minutes and dried at 150°C for at least 30 minutes. Next, the alkali-free glass was washed with UV ozone. Using a mask positioned 2mm from the edges, a calcium film (99.8% purity) was deposited onto the washed alkali-free glass (thickness 200nm).

[0114] A resin sheet having a laminated structure of PET / aluminum foil / resin composition layer having the same resin composition layer as in each example and comparative example was obtained in the same manner as in each example and comparative example, except that an aluminum foil / PET composite film "PET-Tsuki AL1N30" (aluminum foil: 30 μm, PET: 25 μm, manufactured by Tokai Toyo Aluminum Sales Co., Ltd.) was used as the support.

[0115] A sample for evaluation was obtained by laminating alkali-free glass coated with a calcium film using a thermal laminator (Fujiplas Corporation, Lamipacker DAiSY A4 (LPD2325)) inside a glove box, so that the calcium film and the resin composition layer were in contact.

[0116] The reflectance spectrum of the evaluation sample obtained as described above was measured using a fiber optic spectrophotometer (MCPD-7700, model 311C, manufactured by Otsuka Electronics Co., Ltd., external light source unit: halogen lamp MC-2564 (24V, 150W specification)) equipped with a φ60 mm integrating sphere (model name SRS-99-010, reflectance 99%), and the reflectance (%) at a wavelength of 850 nm was calculated and this value was defined as Y2.

[0117] Next, the evaluation samples were heated for 39 hours on a hot plate at 80°C inside a glove box. After heating, the reflectance spectrum of the evaluation samples was measured, and this value was defined as Y1.

[0118] The reflectance ratio Y (=Y1 / Y2) was calculated from the obtained Y1 and Y2, and the suppression of calcium film degradation due to moisture contained in the semi-calcined hydrotalcite of the resin composition layer was evaluated according to the following criteria. The results are shown in the table below. In this case, for Comparative Examples 1 to 4, where the reflectance spectrum Y1 could not be measured due to calcium film degradation due to moisture, the results were evaluated as poor (×). Good (○): Reflectance ratio Y is 0.90 or higher. Acceptable (△): Reflectance ratio Y is less than 0.90 Defective (×): Reflectance spectrum Y1 cannot be measured due to deterioration of the calcium film caused by moisture.

[0119] [Table 1] [Industrial applicability]

[0120] The resin composition of the present invention and the resin sheet using the same are useful for encapsulating electronic devices (e.g., organic EL devices, sensor devices, solar cells, etc.).

[0121] This application is based on Japanese Patent Application No. 2019-180606, which was filed in Japan, and its contents are fully encompassed in the specification of this application.

Claims

1. A resin composition comprising a polyolefin resin, semi-calcined hydrotalcite, and a tackifier, wherein the polyolefin resin comprises a polyolefin resin having acid anhydride groups and / or a polyolefin resin having epoxy groups, the semi-calcined hydrotalcite content is more than 45% by mass relative to 100% by mass of the non-volatile content of the resin composition, the tackifier content is 10% by mass or more and 30% by mass or less relative to 100% by mass of the non-volatile content of the resin composition, and the water content is 2,500 ppm or less on a mass basis relative to the entire resin composition.

2. The resin composition according to claim 1, wherein the water content is 2,000 ppm or less by mass relative to the entire resin composition.

3. The resin composition according to claim 1 or 2, wherein the content of semi-calcined hydrotalcite is more than 45% by mass and 80% by mass or less, based on 100% by mass of the non-volatile content of the resin composition.

4. A resin composition according to any one of claims 1 to 3, used for sealing electronic devices.

5. The resin composition according to claim 4, wherein the electronic device is an organic EL device or a solar cell.

6. A resin sheet having a support and a layer of the resin composition according to any one of claims 1 to 3 provided on the support.

7. A resin sheet according to claim 6, used for sealing electronic devices.

8. The resin sheet according to claim 7, wherein the electronic device is an organic EL device or a solar cell.

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