Two-component curable polyurethane resin composition

Abstract

To provide a two-component curable polyurethane resin composition that yields a cured product with enhanced moisture and heat resistance to address the problem in which there are some cases where conventional sealing materials e.g., for electrical and electronic components fail to meet increasing performance expectations.SOLUTION: A two-component curable polyurethane resin composition comprises a first component containing a polyol (A), and a second component containing a polyisocyanate (B), where the polyol (A) contains a polybutadiene polyol (A1) with a hydroxyl value of 100 mgKOH / g or less. Various options for the polyisocyanate (B) are available.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to a two-component curable polyurethane resin composition. [Background technology]

[0002] In recent years, higher reliability is required for electric and electronic components. These electric and electronic components may be sealed with a sealant to prevent shock, vibration, contamination, condensation, and the like. For example, a cured product of a two-component curing polyurethane resin composition is used as such a sealant. For example, Patent Document 1 discloses sealing electric and electronic components with a polyurethane resin composition containing a polyisocyanate, a castor oil-based polyol, and a polyfarnesene polyol. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2019-182901 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, as the performance requirements for sealing materials for electric and electronic components improve, conventional sealing materials may not be sufficient. [Means for solving the problem]

[0005] The present invention has been made in order to solve the above-mentioned problems, and an object of the present invention is to provide a two-component curing polyurethane resin composition which is capable of giving a cured product having higher moist heat resistance.

[0006] The present invention includes, for example, the embodiments shown below.

[0007] [1] A two-component curing polyurethane resin composition comprising a first component containing a polyol (A) and a second component containing a polyisocyanate (B), wherein the polyol (A) contains a polybutadiene-based polyol (A1) having a hydroxyl value of 100 mgKOH / g or less.

[0008] [2] The two-component curable polyurethane resin composition according to [1], wherein the polybutadiene-based polyol (A1) is contained in an amount of 1 to 85 parts by mass per 100 parts by mass of the two-component curable polyurethane resin composition.

[0009] [3] The two-component curing polyurethane resin composition according to [1] or [2], wherein the polybutadiene-based polyol (A1) is contained in an amount of 50 to 850 parts by mass per 100 parts by mass of the polyisocyanate (B).

[0010] [4] The two-component curing polyurethane resin composition according to any one of [1] to [3], which is used for sealing electric and electronic components.

[0011] [5] An encapsulant obtained by curing the two-component curing polyurethane resin composition according to any one of [1] to [4].

[0012] [6] An electric / electronic component that is resin-encapsulated using the encapsulant described in [5]. Effect of the Invention

[0013] According to an embodiment of the present invention, a two-component curing polyurethane resin composition having excellent moist heat resistance can be provided. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] Preferred embodiments of the present invention will now be described.

[0015] The two-component curing polyurethane resin composition according to the present embodiment is a polyurethane resin composition comprising a first component containing a polyol (A) and a second component containing a polyisocyanate (B), in which the polyol (A) contains a polybutadiene-based polyol (A1) having a hydroxyl value of 100 mgKOH / g or less. Each component will be described below.

[0016] <First component> [Polyol (A)] The first component contains a polyol (A). The content of the polyol (A) is not particularly limited, but is preferably 1 to 95 parts by mass, more preferably 2 to 93 parts by mass, and even more preferably 5 to 93 parts by mass, relative to 100 parts by mass of the two-component curing polyurethane resin composition.

[0017] The content of polyol (A) is not particularly limited, but is preferably 50 to 96 parts by mass, more preferably 55 to 95 parts by mass, and even more preferably 60 to 94 parts by mass, relative to 100 parts by mass of the total of polyol (A) and polyisocyanate (B).

[0018] The polyol (A) includes a polybutadiene-based polyol (A1). The polybutadiene-based polyol (A1) is preferably one having a polybutadiene structure of 1,4-bond type, 1,2-bond type or a mixture thereof in the molecule and at least two hydroxyl groups, and more preferably one having a hydroxyl group at each end of the polybutadiene structure.

[0019] In this specification, the polybutadiene polyol (A1) refers to a polybutadiene polyol (A1-1) and / or a hydrogenated polybutadiene polyol (A1-2) in which some or all of the unsaturated double bonds have been hydrogenated.

[0020] The hydroxyl value of the polybutadiene polyol (A1-1) is not particularly limited, but is preferably 5 to 100 mgKOH / g, more preferably 30 to 90 mgKOH / g, and even more preferably 65 to 85 mgKOH / g. The hydroxyl value of the polybutadiene polyol (A1-1) may be 40 to 50 mgKOH / g.

[0021] The acid value of the polybutadiene polyol (A1-1) is not particularly limited, but is preferably 0.0001 to 0.01 mgKOH / g, more preferably 0.0005 to 0.001 mgKOH / g, and further preferably 0.0007 to 0.001 mgKOH / g. The acid value of the polybutadiene polyol (A1-1) may be 0.3 to 0.5 mgKOH / g.

[0022] The acid value of the polybutadiene polyol (A1-1) is measured in accordance with JIS K0070-1992.

[0023] The viscosity of the polybutadiene polyol (A1-1) is not particularly limited, but is preferably 500 to 5000 mPa·s, more preferably 1000 to 4000 mPa·s, and even more preferably 1500 to 3500 mPa·s, and may also be 4000 to 6000 mPa·s.

[0024] The above viscosity is a value calculated by adjusting the polybutadiene polyol (A1-1) to 30° C. and using a BM type viscometer.

[0025] The number average molecular weight (Mn) of the polybutadiene polyol (A1-1) is preferably from 1500 to 6000, more preferably from 1500 to 5500, and further preferably from 2000 to 5000. The number average molecular weight (Mn) of the polybutadiene polyol (A1-1) may be from 5000 to 6000.

[0026] The weight average molecular weight (Mw) of the polybutadiene polyol (A1-1) is preferably 4000 to 8500, more preferably 5000 to 8000 or more, and further preferably 6500 to 7500 or more. The weight average molecular weight (Mw) of the polybutadiene polyol (A1-1) may be 10000 to 12000.

[0027] The number average molecular weight (Mn) and weight average molecular weight (Mw) of the polybutadiene polyol are values ​​measured by GPC (gel permeation chromatography) and calculated using a calibration curve of standard polystyrene. In detail, the GPC conditions are as follows: column: "TSKgel G4000HXL+TSKgel G3000HXL+TSKgel G2000HXL+TSKgel G1000HXL+TSKgel G1000HXL" manufactured by Tosoh Corporation, mobile phase: THF (tetrahydrofuran), mobile phase flow rate: 1.0 mL / min, column temperature: 40°C, sample injection amount: 50 μL, sample concentration: 0.2 mass%.

[0028] The polydispersity (Mw / Mn) of the polybutadiene polyol (A1-1) is not particularly limited, but is preferably from 1.4 to 2.8, more preferably from 1.6 to 2.6, and even more preferably from 1.8 to 2.6.

[0029] The hydrogenated polybutadiene polyol (A1-2) has a structure in which hydrogen is added to the polybutadiene polyol (A1-1), and some or all of the unsaturated double bonds contained in the polybutadiene polyol (A1-1) are hydrogenated. The degree of hydrogenation of the hydrogenated polybutadiene polyol (A1-2) is not particularly limited, and the iodine value may be 50 g / 100 g or less, 60 g / 100 g or less, or 70 g / 100 g or less.

[0030] The iodine value of the hydrogenated polybutadiene polyol (A1-2) is measured in accordance with JIS K0070:1992.

[0031] The hydroxyl value of the hydrogenated polybutadiene polyol (A1-2) is not particularly limited, but is preferably from 10 to 100 mgKOH / g, more preferably from 15 to 100 mgKOH / g, and further preferably from 20 to 100 mgKOH / g.

[0032] The average number of functional groups of the polybutadiene-based polyol (A1) is not particularly limited, but is preferably from 1.5 to 4.0, more preferably from 1.8 to 3.0, and even more preferably from 2.2 to 2.6.

[0033] The content of the polybutadiene-based polyol (A1) is not particularly limited, but is preferably 1 to 85 parts by mass, more preferably 3 to 83 parts by mass, and even more preferably 5 to 81 parts by mass, relative to 100 parts by mass of the two-component curing polyurethane resin composition. When the content of the polybutadiene-based polyol (A1) is within the above range, it is possible to improve the moist heat resistance and the electrical insulation.

[0034] The content of the polybutadiene-based polyol (A1) is not particularly limited, but is preferably 5 to 100 parts by mass, more preferably 6 to 100 parts by mass, and even more preferably 7 to 100 parts by mass, per 100 parts by mass of the polyol (A). When the content of the polybutadiene-based polyol (A1) is within the above range, it is possible to improve the moist heat resistance and the electrical insulation.

[0035] The content of the polybutadiene-based polyol (A1) is not particularly limited, but is preferably 50 to 850 parts by mass, more preferably 70 to 850 parts by mass, and even more preferably 90 to 840 parts by mass, relative to 100 parts by mass of the polyisocyanate (B). When the content of the polybutadiene-based polyol (A1) is within the above range, the moist heat resistance and the electrical insulation can be improved.

[0036] As the polybutadiene-based polyol (A1), either the polybutadiene polyol (A1-1) or the hydrogenated polybutadiene polyol (A1-2) may be used, or both may be used. From the viewpoint of tensile properties, it is preferable to use the polybutadiene polyol (A1-1).

[0037] The polyol (A) may contain, in addition to the polybutadiene-based polyol (A1), for example, a castor oil-based polyol (A2), a polyester polyol (A3), a polyether polyol (A4), a dimer acid polyol (A5), a polyfarnesene polyol (A6), other polyols (A7), etc. The polyols other than the polybutadiene-based polyol may be used alone or in combination of two or more kinds in addition to the polybutadiene-based polyol (A1).

[0038] As described above, the polyol (A) may contain the castor oil-based polyol (A2). By adding the castor oil-based polyol (A2), the tensile properties and adhesion can be improved.

[0039] As the castor oil-based polyol (A2), castor oil, castor oil fatty acid, ester exchange product of castor oil and other natural fats and oils, reaction product of castor oil and polyhydric alcohol, esterification reaction product of castor oil fatty acid and polyhydric alcohol, polyol obtained by addition polymerization of these with alkylene oxide, or polyol produced by hydrogenating these to hydrogenated castor oil or hydrogenated castor oil fatty acid can be used. The castor oil-based polyol (A2) may be used alone or in combination of two or more kinds.

[0040] The hydroxyl value of the castor oil-based polyol (A2) is not particularly limited, but is preferably from 50 to 250 mgKOH / g, more preferably from 70 to 180 mgKOH / g, and even more preferably from 100 to 180 mgKOH / g.

[0041] The average number of functional groups of the castor oil-based polyol (A2) is not particularly limited, but is preferably from 2.0 to 4.0, more preferably from 2.0 to 3.5, and even more preferably from 2.0 to 3.0.

[0042] The content of the castor oil-based polyol (A2) is not particularly limited, but is preferably 0.5 to 40 parts by mass, more preferably 0.6 to 30 parts by mass, and even more preferably 0.7 to 20 parts by mass, relative to 100 parts by mass of the two-component curing polyurethane resin composition. When the content of the castor oil-based polyol (A2) is within the above range, the moist heat resistance can be improved.

[0043] The content of the castor oil-based polyol (A2) is not particularly limited, but is preferably 3 to 50 parts by mass, more preferably 3 to 45 parts by mass, and even more preferably 5 to 40 parts by mass, relative to 100 parts by mass of the polyol (A). When the content of the castor oil-based polyol (A2) is within the above range, the moist heat resistance can be improved.

[0044] The content of the castor oil-based polyol is not particularly limited, but is preferably 5 to 120 parts by mass, more preferably 5 to 100 parts by mass, and even more preferably 5 to 80 parts by mass, per 100 parts by mass of the polybutadiene-based polyol (A1).

[0045] As described above, the polyol (A) may contain the polyester polyol (A3). The addition of the polyester polyol (A3) can improve the tensile properties and adhesion.

[0046] The polyester polyol (A3) is not particularly limited, but can be obtained, for example, by an esterification reaction between a polyol component and an acid component.

[0047] The polyol component is not particularly limited, but examples thereof include ethylene glycol, diethylene glycol, 1,3-butanediol, 1,4-butanediol, neopentyl glycol, 3-methyl-1,5-pentanediol, 2-butyl-2-ethyl-1,3-propanediol, 2,4-diethyl-1,5-pentanediol, 1,2-hexanediol, 1,6-hexanediol, 1,8-octanediol, 1,9-nonanediol, 2-methyl-1,8-octanediol, 1,8-decanediol, octadecanediol, glycerin, trimethylolpropane, pentaerythritol, hexanetriol, and polypropylene glycol.

[0048] The acid component is not particularly limited, but examples thereof include succinic acid, methylsuccinic acid, adipic acid, pimelic acid, azelaic acid, sebacic acid, 1,12-dodecanedioic acid, 1,14-tetradecanedioic acid, dimer acid, 2-methyl-1,4-cyclohexanedicarboxylic acid, 2-ethyl-1,4-cyclohexanedicarboxylic acid, terephthalic acid, isophthalic acid, phthalic acid, isophthalic acid, terephthalic acid, 1,4-naphthalenedicarboxylic acid, 4,4'-biphenyldicarboxylic acid, and acid anhydrides thereof.

[0049] The hydroxyl value of the polyester polyol (A3) is not particularly limited, but is preferably from 10 to 250 mgKOH / g, more preferably from 50 to 220 mgKOH / g, and further preferably from 100 to 180 mgKOH / g.

[0050] The average number of functional groups of the polyester polyol (A3) is not particularly limited, but is preferably from 1.2 to 4.0, more preferably from 1.5 to 3.0, and even more preferably from 1.5 to 2.8.

[0051] The content of polyester polyol (A3) is not particularly limited, but is preferably 1 to 30 parts by mass, more preferably 1 to 20 parts by mass, and even more preferably 1 to 10 parts by mass, relative to 100 parts by mass of the two-component curing polyurethane resin composition. When the content of polyester polyol (A3) is within the above range, the tensile properties and heat resistance can be improved.

[0052] The content of polyester polyol (A3) is not particularly limited, but is preferably 1 to 30 parts by mass, more preferably 1 to 25 parts by mass, and even more preferably 1 to 20 parts by mass, per 100 parts by mass of polyol (A). When the content of polyester polyol (A3) is within the above range, the tensile properties and heat resistance can be improved.

[0053] The content of the polyester polyol (A3) is not particularly limited, but is preferably 1 to 50 parts by mass, more preferably 3 to 40 parts by mass, and even more preferably 5 to 30 parts by mass, per 100 parts by mass of the polybutadiene-based polyol (A1). When the content of the polyester polyol (A3) is within the above range, the tensile properties and heat resistance can be improved.

[0054] As described above, the polyol (A) may contain the polyether polyol (A4). The addition of the polyether polyol (A4) can improve the tensile properties.

[0055] The polyether polyol (A4) is not particularly limited, but can be produced, for example, by using an active hydrogen group-containing compound as a starting material (initiator) and subjecting the starting material to a ring-opening addition reaction with an alkylene oxide in the presence of a catalyst.

[0056] The polyether polyol (A4) is an alkylene oxide adduct of an active hydrogen group-containing compound.

[0057] The active hydrogen group-containing compound is not particularly limited, but examples thereof include polyhydric alcohols, alkanolamines, polyamines, etc., and any one of these may be used alone or two or more of them may be used in combination.

[0058] The polyhydric alcohol is not particularly limited, but examples thereof include trihydric alcohols such as glycerin, trimethylolpropane, trimethylolethane, butanetriol, and hexanetriol; tetrahydric alcohols such as pentaerythritol and diglycerin; pentahydric alcohols such as a glycerin trimer, glucose, and mannose; hexahydric alcohols such as a glycerin tetramer, sorbitol, mannitol, and dipentaerythritol; and any one of these may be used alone or in combination of two or more.

[0059] The alkanolamine is not particularly limited, but examples thereof include those having three functional groups such as ethanolamine, diethanolamine, triethanolamine, methanolamine, and isopropanolamine, and any one of these may be used alone or in combination of two or more.

[0060] The polyamine is not particularly limited, but examples thereof include those having a functionality of 4, such as ethylenediamine, tolylenediamine, diethyltoluenediamine, 1,3-propanediamine, 1,6-hexanediamine, and isophoronediamine, those having a functionality of 5, such as diethylenetriamine, and those having a functionality of 6, such as triethylenetetramine. Any of these may be used alone or in combination of two or more.

[0061] The hydroxyl value of the polyether polyol (A4) is not particularly limited, but is preferably from 10 to 1000 mgKOH / g, more preferably from 30 to 900 mgKOH / g, and even more preferably from 50 to 800 mgKOH / g.

[0062] The average number of functional groups of the polyether polyol (A4) is not particularly limited, but is preferably from 1.4 to 4.0, more preferably from 1.5 to 4.0, and even more preferably from 1.6 to 3.8.

[0063] The content of polyether polyol (A4) is not particularly limited, but is preferably 0.3 to 40 parts by mass, more preferably 0.4 to 30 parts by mass, and even more preferably 0.5 to 20 parts by mass, relative to 100 parts by mass of the two-component curing polyurethane resin composition. When the content of polyether polyol (A4) is within the above range, the tensile properties and heat resistance can be improved.

[0064] The content of polyether polyol (A4) is not particularly limited, but is preferably 0.3 to 50 parts by mass, more preferably 0.4 to 40 parts by mass, and even more preferably 0.5 to 30 parts by mass, relative to 100 parts by mass of polyol (A). When the content of polyether polyol (A4) is within the above range, the tensile properties and heat resistance can be improved.

[0065] The content of the polyether polyol (A4) is not particularly limited, but is preferably 0.3 to 40 parts by mass, more preferably 0.4 to 30 parts by mass, and even more preferably 0.5 to 20 parts by mass, relative to 100 parts by mass of the polybutadiene-based ol (A1). When the content of the polyether polyol (A4) is within the above range, the tensile properties and heat resistance can be improved.

[0066] As described above, the polyol (A) may contain the dimer acid polyol (A5). By adding the dimer acid polyol (A5), the heat resistance and adhesiveness can be improved.

[0067] The dimer acid polyol (A5) is not particularly limited, but for example, a reaction product of a dimer acid with a diol, a triol, an alkylene glycol, etc. may be used. The dimer acid polyol (A5) may be used alone or in combination of two or more kinds.

[0068] The hydroxyl value of the dimer acid polyol (A5) is not particularly limited, but is preferably from 2 to 1,000 mgKOH / g, more preferably from 30 to 500 mgKOH / g, and further preferably from 30 to 300 mgKOH / g.

[0069] The average number of functional groups of the dimer acid polyol (A5) is not particularly limited, but is preferably from 1.8 to 5.5, more preferably from 2.0 to 5.0, and even more preferably from 2.0 to 4.0.

[0070] The content of the dimer acid polyol (A5) is not particularly limited, but is preferably 1 to 30 parts by mass, more preferably 3 to 25 parts by mass, and even more preferably 5 to 20 parts by mass, relative to 100 parts by mass of the two-component curing polyurethane resin composition. When the content of the dimer acid polyol (A5) is within the above range, the heat resistance, adhesion, and moisture resistance can be improved.

[0071] The content of the dimer acid polyol (A5) is not particularly limited, but is preferably 1 to 60 parts by mass, more preferably 3 to 55 parts by mass, and even more preferably 5 to 50 parts by mass, relative to 100 parts by mass of the polyol (A). When the content of the dimer acid polyol (A5) is within the above range, the heat resistance, adhesiveness, and moisture resistance can be improved.

[0072] The content of the dimer acid polyol (A5) is not particularly limited, but is preferably 10 to 90 parts by mass, more preferably 10 to 80 parts by mass, and even more preferably 10 to 70 parts by mass, per 100 parts by mass of the polybutadiene-based polyol (A1).

[0073] As described above, the polyol (A) may contain the polyfarnesene polyol (A6). By adding the polyfarnesene polyol (A6), the heat resistance and the moist heat resistance can be improved.

[0074] The farnesene polyol is a polyol (A) having a farnesene skeleton, and examples of the farnesene include α-farnesene and β-farnesene.

[0075] As the farnesene, either α-farnesene or β-farnesene may be used alone, or both may be used.

[0076] The polyfarnesene polyol (A6) includes not only homopolymers but also polyfarnesene polyol copolymers obtained from farnesene and other monomers. The polyfarnesene polyol (A6) is not particularly limited, but examples thereof include polyfarnesene polyol copolymers derived from farnesene and at least one vinyl monomer.

[0077] The hydroxyl value of the polyfarnesene polyol (A6) is not particularly limited, but is preferably from 2 to 10,000 mgKOH / g, more preferably from 30 to 500 mgKOH / g, and even more preferably from 30 to 300 mgKOH / g.

[0078] The average number of functional groups of the polyfarnesene polyol (A6) is not particularly limited, but is preferably from 1.5 to 5.0, more preferably from 2.0 to 4.5, and even more preferably from 2.0 to 4.0.

[0079] The content of the polyfarnesene polyol (A6) is not particularly limited, but is preferably 0.1 to 90 parts by mass, more preferably 1 to 85 parts by mass, and even more preferably 5 to 85 parts by mass, relative to 100 parts by mass of the two-component curing polyurethane resin composition. When the content of the polyfarnesene polyol (A6) is within the above range, the heat resistance and moisture resistance can be improved.

[0080] The content of the polyfarnesene polyol (A6) is not particularly limited, but is preferably 0.1 to 96 parts by mass, more preferably 1 to 94 parts by mass, and even more preferably 5 to 92 parts by mass, relative to 100 parts by mass of the polyol (A). When the content of the polyfarnesene polyol (A6) is within the above range, the heat resistance and moisture resistance can be improved.

[0081] The content of the polyfarnesene polyol (A6) is not particularly limited, but is preferably 0.1 to 96 parts by mass, more preferably 1 to 94 parts by mass, and even more preferably 5 to 92 parts by mass, per 100 parts by mass of the polybutadiene polyol (A1). When the content of the polyfarnesene polyol (A6) is within the above range, the heat resistance and moisture resistance can be improved.

[0082] As described above, the polyol (A) may contain other polyols (A7). The other polyols (A7) are compounds having multiple hydroxyl groups in the molecule, and include various polyols other than polybutadiene-based polyols (A1), castor oil-based polyols (A2), polyester polyols (A3), polyether polyols (A4), dimer acid polyols (A5), and polyfarnesene polyols (A6). For example, polycarbonate polyols, polycaprolactone polyols, acrylic polyols, polyisoprene polyols, hydrogenated polyisoprene polyols, fluorine polyols, polytetramethylene glycols, polytetramethylene ether glycols, polypropylene glycols, polyols, silicone polyols, and polyolefin polyols. Alternatively, a low molecular weight polyol that is generally used as a crosslinking agent may be used, for example, a polyhydric alcohol having a molecular weight of 300 or less, specifically, an aromatic polyhydric alcohol such as N,N-bis(2-hydroxypropyl)aniline, hydroquinone-bis(β-hydroxyethyl)ether, or resorcinol-bis(β-hydroxyethyl)ether, or an aliphatic polyhydric alcohol such as ethylene glycol, 1,4-butanediol, octanediol, trimethylolpropane, or triisopropanolamine.

[0083] In this specification, the hydroxyl value of the polyol (A) is measured in accordance with Method A of JIS K1557-1:2007.

[0084] <Second component> [Polyisocyanate (B)] As the polyisocyanate (B), various polyisocyanates having two or more isocyanate groups in one molecule can be used. Examples of the polyisocyanate (B) include aliphatic polyisocyanates (B1), alicyclic polyisocyanates (B2), and aromatic polyisocyanates (B3), as well as modified and polynuclear products thereof, and any one of them may be used alone or in combination of two or more.

[0085] Examples of the aliphatic polyisocyanate (B1) include, but are not limited to, tetramethylene diisocyanate, dodecamethylene diisocyanate, hexamethylene diisocyanate (HDI), 2,2,4-trimethylhexamethylene diisocyanate, 2,4,4-trimethylhexamethylene diisocyanate, lysine diisocyanate, 2-methylpentane-1,5-diisocyanate, 3-methylpentane-1,5-diisocyanate, and modified products and polynuclear products thereof.

[0086] The alicyclic polyisocyanate (B2) is not particularly limited, but examples thereof include isophorone diisocyanate (IPDI), hydrogenated xylylene diisocyanate, 4,4'-dicyclohexylmethane diisocyanate, 1,4-cyclohexane diisocyanate, methylcyclohexylene diisocyanate, 1,3-bis(isocyanatemethyl)cyclohexane, and modified products and polynuclear products thereof.

[0087] Examples of the aromatic polyisocyanate (B3) include, but are not limited to, tolylene diisocyanate (TDI, for example, 2,4-TDI, 2,6-TDI), diphenylmethane diisocyanate (MDI, for example, 2,2'-MDI, 2,4'-MDI, 4,4'-MDI), 4,4'-dibenzyl diisocyanate, 1,5-naphthylene diisocyanate, xylylene diisocyanate (XDI), 1,3-phenylene diisocyanate, 1,4-phenylene diisocyanate, and modified products and polynuclear products thereof.

[0088] The modified products of these polyisocyanates (B1) to (B3) are not particularly limited, but examples thereof include isocyanurate modified products, allophanate modified products, biuret modified products, adduct modified products, carbodiimide modified products, and uretdione modified products.

[0089] The isocyanurate-modified product is not particularly limited, but examples thereof include an isocyanurate-modified product of an aliphatic polyisocyanate (B1), an isocyanurate-modified product of an alicyclic polyisocyanate (B2), and an isocyanurate-modified product of an aromatic polyisocyanate (B3).

[0090] As the polyisocyanate (B), an isocyanate-terminated urethane prepolymer obtained by reacting the polyisocyanate (B) with a polyol can be used.

[0091] The content of polyisocyanate (B) is not particularly limited, but is preferably 1 to 50 parts by mass, more preferably 1 to 40 parts by mass, and even more preferably 1 to 30 parts by mass, relative to 100 parts by mass of the two-component curing polyurethane resin composition.

[0092] The content of polyisocyanate (B) is not particularly limited, but is preferably 1 to 50 parts by mass, more preferably 1 to 45 parts by mass, and even more preferably 1 to 40 parts by mass, per 100 parts by mass of polyol (A).

[0093] The ratio of polyol (A) to polyisocyanate (B) is not particularly limited, but for example, the molar ratio NCO / OH (index) of the isocyanate groups of the polyisocyanate (B) to the hydroxyl groups of the polyol (A) is preferably 0.6 to 1.5, more preferably 0.7 to 1.3, and even more preferably 0.8 to 1.2.

[0094] Here, NCO / OH is the molar ratio of isocyanate groups contained in polyisocyanate (B) to hydroxyl groups contained in polyol (A). NCO / OH is calculated using the hydroxyl value of polyol (A) and the isocyanate value of polyisocyanate (B). The isocyanate value is calculated by isocyanate value = {(isocyanate content) x 56110} / (42.02 x 100) using the isocyanate content measured in accordance with JIS K1603-1:2007 Method A.

[0095] In addition to the above-mentioned components, the first component and / or the second component may contain, but is not limited to, various additives such as, for example, a catalyst (C), a plasticizer (D), a filler (E), a flame retardant (F), an antioxidant, a foam stabilizer, an antifoaming agent, a diluent, an ultraviolet absorber, a colorant, a filler, a tackifier, a moisture absorber, an antifungal agent, and a silane coupling agent, within a range that does not impair the object of the present embodiment. In addition, the first component and / or the second component may contain a terpene resin.

[0096] The catalyst (C) is not particularly limited, and examples thereof include various urethane polymerization catalysts such as metal catalysts, such as lead catalysts, organotin catalysts, organolead catalysts, and organobismuth catalysts, and amine catalysts. In addition, organometallic compounds, metal complex compounds, and the like may also be used as the catalyst.

[0097] The content of the catalyst (C) is not particularly limited, but is preferably 0.0001 to 0.7 parts by mass, more preferably 0.001 to 0.5 parts by mass, and even more preferably 0.003 to 0.3 parts by mass, per 100 parts by mass of the two-component curing polyurethane resin composition.

[0098] The plasticizer (D) is not particularly limited, and examples thereof include phthalate ester plasticizers such as dioctyl phthalate, diisononyl phthalate (diisononyl phthalate), and diundecyl phthalate; adipate ester plasticizers such as dioctyl adipate, diisodecyl adipate, and diisononyl adipate; castor oil ester plasticizers such as methyl acetyl ricinoleate, butyl acetyl ricinoleate, acetylated ricinoleic acid triglyceride, and acetylated polyricinoleic acid triglyceride; trioctyl trimellitate, triisononyl trimellitate, and other plasticizers. Examples of such plasticizers include trimellitic acid ester-based plasticizers such as pyromellitate, tetraoctyl pyromellitate, and tetraisononyl pyromellitate; phosphate ester-based plasticizers such as tricresyl phosphate, trisxylenyl phosphate, cresyl diphenyl phosphate, xylenyl phosphate, and triphenyl phosphate; and non-phthalic acid plasticizers such as diisononyl ester. These can be used alone or in combination of two or more to reduce the viscosity of the first component and the second component.

[0099] The content of the plasticizer (D) is not particularly limited, but is preferably 1 to 40 parts by mass or less, more preferably 1 to 35 parts by mass, and even more preferably 1 to 30 parts by mass, per 100 parts by mass of the two-component curing polyurethane resin composition. By making the content of the plasticizer (D) 5 parts by mass or more, the hardness of the polyurethane resin after curing can be reduced.

[0100] The filler (E) is preferably contained in the first component. When the filler is contained in the first component, poor curing of the polyurethane resin caused by a reaction between the moisture contained in the filler and the polyisocyanate group-containing compound can be suppressed.

[0101] The filler (E) is not particularly limited, but examples thereof include inorganic fillers and organic fillers, and it is preferable to use an inorganic filler from the viewpoint of flame retardancy. As the filler, one type of filler may be used alone, or two or more types of fillers may be used in combination.

[0102] Examples of inorganic fillers include hydroxides such as aluminum hydroxide, calcium hydroxide, and magnesium hydroxide; oxides such as aluminum oxide (alumina), magnesium oxide, beryllium oxide, and silicon oxide (silica); carbides such as aluminum carbide and silicon carbide; metal carbonates such as calcium carbonate, magnesium carbonate, and barium carbonate, and dawsonite.

[0103] Examples of the resin material constituting the organic filler include polystyrene resin, polyamide resin, polyimide resin, polyethylene resin, polypropylene resin, polycarbonate resin, acrylic resin, polyvinyl chloride resin, etc. The filler may be a hollow filler.

[0104] The content of the filler (E) is not particularly limited, but is preferably 20 to 90 parts by mass, more preferably 30 to 85 parts by mass, and even more preferably 40 to 85 parts by mass, relative to 100 parts by mass of the two-component curing polyurethane resin composition. When the content of the filler (E) is 40 parts by mass or more, the flame retardancy can be improved, and when it is 85 parts by mass or less, the mixing viscosity during production of the two-component curing polyurethane resin composition can be reduced.

[0105] The flame retardant (F) is not particularly limited, but examples thereof include phosphorus-based flame retardants and nitrogen-based flame retardants, etc. As the flame retardant (F), one type of flame retardant may be used alone, or two or more types of flame retardants may be used in combination.

[0106] Examples of phosphorus-based flame retardants include, but are not limited to, triphenyl phosphate, tricresyl phosphate, trixylenyl phosphate, cresyl di-2,6-xylenyl phosphate, cresyl phenyl phosphate, other aromatic phosphate esters, aromatic condensed phosphate esters, diphenyl monoorthoxenyl phosphate, 2-naphthyl diphenyl phosphate, 10-benzyl-9,10-dihydroxy-9-oxa-10-phosphaphenanthrene-10-oxide, triphenylphosphine oxide, 5,5-dimethyl-2-(2'-phenylphenoxy)-1,3,2-dioxaphosphorinane-2-oxide, tris(chloropropyl)phosphate, and tris(dichloropropyl)phosphate.

[0107] Examples of nitrogen-based flame retardants include, but are not limited to, guanidine-based compounds, guanylurea-based compounds (e.g., guanylurea phosphate), melamine-based compounds (e.g., poly(melamine phosphate), melamine sulfate, melamine cyanurate), and ammonium polyphosphate.

[0108] The content of the flame retardant (F) is not particularly limited, but is preferably 1 to 30 parts by mass, more preferably 1 to 25 parts by mass, and even more preferably 2 to 20 parts by mass, relative to 100 parts by mass of the two-component curing polyurethane resin composition. When the content of the flame retardant (F) is within the above range, the flame retardancy can be improved.

[0109] Terpene resin is a polymer containing terpene as a constituent monomer. Terpene (also called terpene monomer) is not particularly limited, but includes monoterpenes such as α-pinene, β-pinene, limonene (including racemic dipentene), myrcene, alloocimene, ocimene, α-phellandrene, β-phellandrene, α-terpinene, γ-terpinene, and sabinene, and any one or more of these can be used in combination. Among these, monocyclic monoterpenes such as α-pinene, β-pinene, limonene, α-phellandrene, β-phellandrene, α-terpinene, and γ-terpinene are preferred, and at least one selected from the group consisting of α-pinene, β-pinene, and limonene is more preferred.

[0110] The content of the terpene resin is not particularly limited, but is preferably 5 to 60 parts by mass, more preferably 10 to 50 parts by mass, and even more preferably 15 to 40 parts by mass, relative to 100 parts by mass of the two-component curing polyurethane resin composition. When the content of the terpene resin is within the above range, adhesion can be improved.

[0111] The two-component curing polyurethane resin composition according to this embodiment is usually composed of a first liquid as a first component and a second liquid as a second component, but in addition to the first and second components, a third component containing the above-mentioned other components as optional components may also be included as the third liquid.

[0112] The two-component curable polyurethane resin composition can be produced by preparing the first component and the second component separately, that is, the first component and the second component may be filled in different containers. The first component and the second component are mixed at the time of use, whereby the polyol (A) and the polyisocyanate (B) react to form a polyurethane resin, which is cured to form a cured product. At that time, the polyurethane resin may be cured by heating. The two-component curable polyurethane resin composition according to the embodiment may be obtained by mixing the first component and the second component, or may be in a liquid state before curing.

[0113] [Uses of two-component curing polyurethane resin composition] The application of the two-component curing polyurethane resin composition according to the present embodiment is not particularly limited, but it can be used, for example, for sealing electric and electronic components. Examples of the electric and electronic components include transformers such as transformer coils, choke coils, and reactor coils, device control boards, sensors, and wireless communication components.

[0114] Electrical and electronic components resin-encapsulated with the two-component curing polyurethane resin composition according to this embodiment can be used, for example, in electric washing machines, toilet seats, water heaters, water purifiers, baths, dishwashers, solar panels, power tools, automobiles, motorcycles, and the like, without any particular limitation. EXAMPLES

[0115] The two-component curing polyurethane resin composition will be described in detail below based on examples and comparative examples, but the present invention is not limited thereto.

[0116] The raw materials used in the examples and comparative examples are shown below. <Raw materials used> [Polyol (A)] [Polybutadiene polyol (A1-1)] Polybutadiene polyol 1 : Polybutadiene polyol with a hydroxyl value of 75 mgKOH / g (acid value: 0.001 mgKOH / g, viscosity (30°C): 2500 mPa·s, number average molecular weight (Mn): 4000, weight average molecular weight (Mw): 7500, average functionality: 2.4) Polybutadiene polyol 2: Polybutadiene polyol with a hydroxyl value of 72 mgKOH / g (acid value: 0.001 mgKOH / g, viscosity (30°C): 2900 mPa·s, number average molecular weight (Mn): 1900, weight average molecular weight (Mw): 4000, average functionality: 2.2) Polybutadiene polyol 3: Polybutadiene polyol with a hydroxyl value of 47 mgKOH / g (acid value: 0.385 mgKOH / g, viscosity (30°C): 4800 mPa·s, number average molecular weight (Mn): 5500, weight average molecular weight (Mw): 10700, average functionality: 2.3, product name: poly bd R-45HT, manufactured by Idemitsu Kosan Co., Ltd.) [Hydrogenated polybutadiene polyol (A1-2)] Hydrogenated polybutadiene polyol 1: Hydrogenated polybutadiene polyol with a hydroxyl value of 68 mgKOH / g (number average molecular weight (Mn): 1500, product name: GI-1000, manufactured by Nippon Soda Co., Ltd.) [Castor oil-based polyol (A2)] Castor oil polyol 1: Castor oil fatty acid-polyhydric alcohol ester with a hydroxyl value of 160 mgKOH / g (average functionality: 2.7, product name: URICH-30, manufactured by Ito Oil Mills) Castor oil polyol 2: Castor oil fatty acid-polyhydric alcohol ester with a hydroxyl value of 160 mgKOH / g (average functionality: 2.0, product name: URICY-403, manufactured by Ito Oil Mills) Castor oil polyol 3: Castor oil fatty acid-polyhydric alcohol ester with a hydroxyl value of 160 mgKOH / g (product name: Castor Oil D, manufactured by Ito Oil Mills) [Polyester polyol (A3)] Polyester polyol 1: Polyester polyol with a hydroxyl value of 56 mgKOH / g (product name: Kuraray Polyol P-2050, manufactured by Kuraray Co., Ltd.) [Polyether polyol (A4)] Polyether polyol 1: Polypropylene glycol with a hydroxyl value of 400 mg KOH / g (product name: EXCENOL 430, manufactured by AGC) Polyether polyol 2: Polypropylene glycol with a hydroxyl value of 112 mgKOH / g (product name: EXCENOL 1020, manufactured by AGC) [Dimer acid polyol (A5)] Dimer acid polyol 1: Dimer acid polyol with a hydroxyl value of 207 mgKOH / g (product name: Pripol 2033-LQ-(GD), manufactured by Croda Japan) [Polyfarnesene polyol (A6)] Polyfarnesene polyol 1: Polyfarnesene polyol with a hydroxyl value of 37 mgKOH / g (product name: Krasol F3000, manufactured by CRAY VALLEY) [Other polyols (A7)] Other polyol 1: Polyol with a hydroxyl value of 529 mg KOH / g (product name: OK All 100, manufactured by Okahata Sangyo Co., Ltd.) Other polyol 2: Polyol with a hydroxyl value of 774 mg KOH / g (product name: Octanediol, manufactured by KH Neochem Co., Ltd.) [Isocyanate (B)] [Aliphatic polyisocyanates (B1)] Aliphatic polyisocyanate 1: HMDI (product name: WANNATE HMDI, manufactured by Wanka Chemical Japan Co., Ltd.) [Alicyclic polyisocyanate (B2)] Alicyclic polyisocyanate 1: IPDI (product name: WANNATE IPDI, manufactured by Wanka Chemical Japan Co., Ltd.) [Aromatic polyisocyanates (B3)] Aromatic polyisocyanate 1: Polymeric MDI (product name: Millionate MR-200, manufactured by Tosoh Corporation) Aromatic polyisocyanate 2: Crude MDI (product name: Luplanate M5S, manufactured by BASF INOAC Polyurethanes) [Modified polyisocyanates (B1) to (B3)] Polyisocyanurate modified material 1: HMDI isocyanurate modified material (product name: Duranate TPA-100, manufactured by Asahi Kasei Chemicals Corporation) Polyisocyanurate modified material 2: HMDI isocyanurate modified material (product name: Duranate TLA-100, manufactured by Asahi Kasei Chemicals Corporation) Biuret modified substance 1: HMDI biuret modified substance (product name: Duranate 24A-100, manufactured by Asahi Kasei Chemicals Corporation) Alphanate modified substance 1: HDI allophanate modified substance (product name: Duranate A201H, manufactured by Asahi Kasei Chemicals Corporation) Carbodiimide modified substance 1: Carbodiimide modified MDI (product name: Millionate MTL, manufactured by Tosoh Corporation) [Catalyst (C)] Catalyst: Dioctyltin dilaurate (product name: Neostan U-810, manufactured by Nitto Kasei Co., Ltd.) [Plasticizer (D)] Plasticizer 1: Diundecyl phthalate (product name: DUP, manufactured by JPlus Corporation) Plasticizer 2: Diisodecyl adipate (product name: DIDA, manufactured by JPlus Corporation) Plasticizer 3: Diisononyl phthalate (product name: DINP, manufactured by JPlus Corporation) Plasticizer 4: Trimellitic acid ester (product name: TOTM, manufactured by JPlus Corporation) Plasticizer 5: 1,2-cyclohexanedicarboxylic acid diisononyl ester (product name: Hexamol DINCH, manufactured by BASF) Filler Filler 1: Aluminum hydroxide (product name: Hijilite H-32, manufactured by Showa Denko) Filler 2: Aluminum hydroxide (product name: Hijilite H-42I, manufactured by Showa Denko) Filler 3: Aluminum hydroxide (product name: C-305, manufactured by Sumitomo Chemical Co., Ltd.) Filler 4: Aluminum hydroxide (product name: BX-053, manufactured by Nippon Light Metal Co., Ltd.) Filler 5: Hollow filler (product name: Expancel 920 DE 40 d30, manufactured by Nippon Fillite Co., Ltd.) Filler 6: Hollow filler (product name: Expancel 920 DE 80 d30, manufactured by Nippon Fillite Co., Ltd.) Filler 7: Hollow filler (product name: Expancel 031 DU 40, manufactured by Nippon Fillite Co., Ltd.) Filler 8: Magnesium hydroxide (product name: ECOMAG, manufactured by Tateho Chemical Industries Co., Ltd.) [Flame retardant (F)] Flame retardant 1: Tricresyl phosphate (product name: TCP, manufactured by Daihachi Chemical Industry Co., Ltd.) Flame retardant 2: Trixylenyl phosphate (product name: TXP, manufactured by Daihachi Chemical Industry Co., Ltd.) Flame retardant 3: Cresyl di-2,6-xylenyl phosphate (product name: PX-100, manufactured by Daihachi Chemical Industry Co., Ltd.) [Antioxidants] Antioxidant: Pentaerythritol tetrakis[3-(3',5'-di-tert-butyl-4'-hydroxyphenyl)propionate] (product name: IrganoX1010, manufactured by BASF) [Antifoaming agent] Defoamer: Silicone defoamer (product name: SC-5570, manufactured by Dow Corning Toray) [Examples 1 to 88] The raw materials were mixed as shown in Tables 1 to 7 to obtain the first component and the second component. Specifically, the first component was prepared by stirring and mixing the raw materials while appropriately heating them to dissolve them, and adjusting the temperature to 25°C after mixing. Specifically, when two or more raw materials were used, the second component was prepared by stirring and mixing the raw materials, and adjusting the temperature to 25°C after mixing. Subsequently, the second component was added to the first component, and the mixture was stirred and mixed, and degassed to obtain a two-component curing polyurethane resin composition.

[0117] The compatibility, hardness, adhesion, dielectric constant, tensile properties (tensile strength and tensile elongation), volume resistivity, dielectric breakdown, moisture resistance, heat resistance, moist heat resistance, thermal conductivity, flame retardancy, workability, and pot life of each two-component curing polyurethane resin composition were measured and evaluated. The measurement and evaluation methods are as follows.

[0118] [compatibility] The state of the liquid after mixing with the first component was checked, and the compatibility of the first component was evaluated according to the following criteria. In the case of D, separation occurred, so other evaluations were not performed. A:Transparent B: Cloudy C: Separation occurs after 30 minutes or more D: Separation occurs in less than 30 minutes

[0119] [hardness] The defoamed two-component curing polyurethane resin composition was poured into a metal mold and cured at 80° C. for 16 hours (overnight) to prepare a 10 mm thick resin sheet. The hardness of the resin sheet thus obtained was measured using a type A durometer according to JIS K6253, and evaluated according to the following evaluation criteria. A: Over A90 B: More than A80 and less than A90 C: Over A70 and below A80 D: Over A60 and below A70 E: Over A40 and below A60 F:A20 or more and A40 or less G: Less than A20

[0120] [Adhesion] The degassed two-component curing polyurethane resin composition was dropped onto a commercially available FR-4 epoxy board in a circle with a diameter of 1 cm, and cured at 80°C for 16 hours (overnight) to cure. A utility knife was inserted into the boundary between the cured polyurethane resin and the epoxy board, the resin was peeled off, and the polyurethane resin remaining on the board was visually confirmed. The evaluation was performed according to the area ratio according to the following criteria, with the state in which the polyurethane resin remained on the board being "cohesive failure" and the state in which the polyurethane resin peeled off from the board being "interface peeling." The greater the rate of cohesive failure, the better the adhesion. A: 100% cohesive failure B: Cohesive failure is 75% or more and less than 100%, and interfacial peeling is more than 0% and less than 25%. C: Cohesive failure is 50% or more and less than 75%, and interfacial peeling is more than 25% and less than 50%. D: Cohesive failure is 25% or more and less than 50%, and interfacial peeling is more than 50% and less than 75%. E: Cohesive failure less than 25%, interfacial peeling 75% or more

[0121] [Dielectric constant] The degassed two-component curing polyurethane resin composition was poured into a 3 mm thick mold and cured at 80°C for 16 hours (overnight) to prepare a 3 mm thick resin sheet. The resin sheet was cut into 50 mm x 50 mm x 3 mm sheets to be used as measurement samples. The measurement was performed using an Agilent Technologies Inc. device (main body model: E4980A, name: Precision LCR Meter, electrode part model: 16451B, name: DIELECTRIC TESTFIXTURE), and the relative dielectric constant value at a frequency of 1 MHz was measured and evaluated according to the following criteria. A: Dielectric constant is 2.8 or less B: Dielectric constant is greater than 2.8 and less than or equal to 3.0 C: Dielectric constant is greater than 3.0 and less than or equal to 3.2 D: Dielectric constant is greater than 3.2 and less than or equal to 3.4 E: Dielectric constant greater than 3.4

[0122] [Tensile properties (tensile strength and tensile elongation)] The degassed two-component curing polyurethane resin composition was poured into a 3 mm thick mold and cured at 80°C for 16 hours (overnight) to produce a 3 mm thick resin sheet. The resin sheet was punched into a dumbbell-shaped No. 3 mold to prepare a measurement sample. The measurement was performed three times using a Shimadzu Corporation device (main body model: AG-X Plus, name: Shimadzu precision universal testing machine Autograph) with a tensile speed set to 500 mm / min and a chuck distance of 40 mm, and the average values ​​of tensile strength (breaking stress) and tensile elongation (elongation at break) were calculated and evaluated according to the following criteria. (Evaluation criteria for tensile strength) A: Tensile strength is 3.0 MPa or more B: Tensile strength is 2.5MPa or more and less than 3.0MPa C: Tensile strength is 2.0MPa or more and less than 2.5MPa D: Tensile strength is 1.5 MPa or more and less than 2.0 MPa E: Tensile strength is less than 1.5MPa (Evaluation criteria for tensile elongation) A: Elongation rate is 130% or more B: Elongation rate is 110% or more and less than 130% C: Elongation rate is 90% or more but less than 110% D: Elongation rate is 70% or more but less than 90% E: Elongation rate is less than 70%

[0123] [Volume resistivity] The degassed two-component curing polyurethane resin composition was poured into a 3 mm thick mold and cured at 80° C. for 16 hours (overnight) to prepare a 3 mm thick resin sheet. The resin sheet was cut into 30 mm×30 mm×3 mm sheets as measurement samples, which were treated in a high-temperature, high-humidity tank at 121° C., 100% humidity, and 2 atm. After 500 hours, 750 hours, and 1000 hours, the volume resistivity was measured in accordance with JIS K6911 (measurement voltage: 500 V) and evaluated according to the following criteria. A: The volume resistivity after 1000 hours is 10 9 Ω cm or more B: Volume resistivity after 1000 hours is 10 9 Less than Ω·cm and volume resistivity after 750 hours is 10 9 Ω cm or more C: Volume resistivity after 750 hours is 10 9 Less than Ω·cm and volume resistivity after 500 hours is 10 9 Ω cm or more D: Volume resistivity after 500 hours is 10 9 Less than Ω cm

[0124] [Dielectric breakdown] The defoamed two-component curing polyurethane resin composition was poured into a 3 mm thick mold and cured at 80° C. for 16 hours (overnight) to prepare a 3 mm thick resin sheet. The resin sheet was cut into sheets of 30 mm×30 mm×3 mm to prepare measurement samples. The dielectric breakdown strength was measured using a dielectric breakdown strength measuring device in accordance with JIS C2105, and the dielectric breakdown strength was evaluated according to the following evaluation procedure. A: 22kV / mm or more B: 20kV / mm or more and less than 22kV / mm C: Less than 20kV / mm

[0125] [Moisture resistance] The defoamed two-component curing polyurethane resin composition was poured into a 3 mm thick mold and cured at 80° C. for 16 hours (overnight) to prepare a 3 mm thick resin sheet. The resin sheet was cut into 30 mm×30 mm×3 mm sheets to prepare measurement samples. The measurement samples were subjected to a pressure cooker test under conditions of 121° C., 100% RH, and 200 hours. The hardness (type A) after the pressure cooker test was measured according to JIS K6253, and the ratio (%) of the hardness after the pressure cooker test to the hardness before the pressure cooker test was calculated as the hardness retention rate, and the moisture resistance was evaluated according to the following evaluation criteria. A: Hardness retention rate is 50% or more B: Hardness retention rate is 20% or more and less than 50% C: Hardness retention is less than 20%

[0126] [Heat resistance] The defoamed two-component curing polyurethane resin composition was poured into a 10 mm thick mold and cured at 80°C for 16 hours (overnight) to prepare a 10 mm thick resin sheet. The resin sheet was cut into sheets of 30 mm x 30 mm x 3 mm to prepare measurement samples. After measuring the initial hardness, the measurement samples were heated in a 100°C dryer for 500 hours, cooled to room temperature (23°C), and then the hardness (final hardness) of the measurement samples was measured in the same manner as the initial hardness. The hardness change rate was calculated from the initial hardness and the final hardness based on the following formula. Hardness change rate (%) = [(final hardness - initial hardness) / initial hardness] x 100 Based on the calculated rate of change in hardness, the heat resistance was evaluated according to the following evaluation criteria. A: Hardness change rate is less than 30% B: Hardness change rate is 30% or more

[0127] [Moisture and heat resistance] The defoamed two-component curing polyurethane resin composition was poured into a 3 mm thick mold and cured at 80°C for 16 hours (overnight) to prepare a 3 mm thick resin sheet. The resin sheet was cut into 30 mm x 30 mm x 3 mm sheets to be used as measurement samples. The measurement was performed using an Espec Corporation device (main body model: EHS-212M, name: highly accelerated life test device), and the state of the resin sheet was confirmed after a predetermined time in a durability test at a temperature of 121°C and a humidity of 100% in the unsaturated control (humidification water temperature control) mode, and the time until the resin melted and could no longer maintain the sheet shape was measured, and the evaluation was performed according to the following criteria. A: More than 500 hours B: 400 hours or more but less than 500 hours C: 300 hours or more but less than 400 hours D: 200 hours or more but less than 300 hours E: Less than 200 hours

[0128] [Thermal Conductivity] The defoamed two-component curing polyurethane resin composition was poured into a 3 mm thick mold and cured at 80°C for 16 hours (overnight) to produce a 3 mm thick resin sheet. The resin sheet was cut into 6 cm x 12 cm x 1 cm samples for measurement. The thermal conductivity was measured using Kyoto Electronics QTM-500 at a temperature of 23°C and a humidity of 60%, and evaluated according to the following criteria. A: Thermal conductivity is 0.6 W / m K or more B: Thermal conductivity is 0.5 W / m K or more and less than 0.6 W / m K C: Thermal conductivity is 0.4 W / m K or more and less than 0.5 W / m K D: Thermal conductivity is 0.3 W / m K or more and less than 0.4 W / m K E: Thermal conductivity is less than 0.3 W / m K

[0129] [Flame retardant] The defoamed two-component curing polyurethane resin composition was poured into 5 mm and 10 mm thick molds and cured at 80°C for 16 hours (overnight) to prepare 5 mm and 10 mm thick resin sheets. The resin sheets were cut into 127 mm x 12.7 mm x 5 mm and 127 mm x 12.7 mm x 10 mm samples for measurement. The test was conducted based on the flame test standard (UL-94) established by Underwriters Laboratories, Inc. in the United States. Flame retardancy was evaluated according to the following evaluation criteria. A: Meets V-0 B: Does not meet V-0 (V-1, V-2 or HB)

[0130] [Workability] The raw materials were mixed as shown in Tables 1 to 7 to obtain the first component and the second component. Specifically, the first component was prepared by mixing the raw materials at 2000 rpm for 3 minutes using a mixer (product name: Awatori Rentaro, manufactured by Shinki Co., Ltd.) and then adjusting the temperature to 23°C. Specifically, the second component was prepared by stirring and mixing two or more raw materials and adjusting the temperature to 23°C. Next, the second component was added to the adjusted first component and mixed at 2000 rpm for 60 seconds. In an atmosphere of 23°C, the viscosity of the mixed liquid 3 minutes after the start of mixing was measured using a BH type viscometer, and the initial mixing viscosity of the polyurethane resin composition before curing was measured. Based on the measured initial mixing viscosity, the workability was evaluated according to the following evaluation criteria. A: Viscosity is 50,000 mPa s or less B: Viscosity exceeds 50,000 mPa·s C: Liquid components cannot be created Furthermore, if the product is rated B or above, it is deemed suitable for practical use.

[0131] [Pot life] The raw materials were blended as shown in Tables 1 to 7 to obtain the first component and the second component. Specifically, the first component was prepared by mixing the raw materials at 2000 rpm for 3 minutes using a mixer (product name: Awatori Rentaro, manufactured by Shinki Co., Ltd.) and then adjusting the temperature to 23°C. Specifically, when there were two or more raw materials, the second component was prepared by stirring and mixing and adjusting the temperature to 23°C. Next, the second component was added to the adjusted first component and mixed at 2000 rpm for 60 seconds. In an atmosphere of 23°C, the time until the viscosity became twice the initial viscosity of the mixture measured in the evaluation of the above-mentioned [workability] was measured. Based on the measured time, the pot life was evaluated according to the following evaluation criteria. A: More than 30 minutes B: More than 10 minutes and less than 30 minutes C: Less than 10 minutes Furthermore, if the product is rated B or above, it is deemed suitable for practical use.

[0132] [Table 1]

[0133] [Table 2]

[0134] [Table 3]

[0135] [Table 4]

[0136] [Table 5]

[0137] [Table 6]

[0138] [Table 7]

[0139] It is clear from Tables 1 to 7 that the two-component curing polyurethane resin composition of the present invention has excellent moist heat resistance.

[0140] In addition, the various numerical ranges described in the specification can be arbitrarily combined with their upper and lower limits, and all such combinations are described in the present specification as preferred numerical ranges. In addition, the description of a numerical range "X to Y" means from X to Y. In addition, the description of "X and / or Y" means any of "X only", "Y only", and "X and Y".

[0141] Although several embodiments of the present invention have been described above, these embodiments are presented as examples and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their omissions, substitutions, modifications, etc. are included in the scope and spirit of the invention, and are also included in the invention and its equivalents described in the claims. etc. are included in the scope of the above. [Industrial Applicability]

[0142] The two-component curing polyurethane resin composition of the present invention has excellent resistance to moist heat and can therefore be used in the fields of electrical products, electronic parts, and the like.

Claims

1. A first component comprising a polyol (A); A second component comprising a polyisocyanate (B), The polyol (A) is a two-component curing polyurethane resin composition containing a polybutadiene-based polyol (A1) having a hydroxyl value of 100 mgKOH / g or less.

2. The two-component curing polyurethane resin composition according to claim 1, wherein the polybutadiene-based polyol (A1) is contained in an amount of 1 to 85 parts by mass per 100 parts by mass of the two-component curing polyurethane resin composition.

3. The two-component curing polyurethane resin composition according to claim 1 or 2, wherein the polybutadiene-based polyol (A1) is contained in an amount of 50 to 850 parts by mass per 100 parts by mass of the polyisocyanate (B).

4. The two-component curing polyurethane resin composition according to claim 1 or 2, which is used for sealing electric and electronic components.

5. A sealing material obtained by curing the two-component curing polyurethane resin composition according to claim 1 or 2.

6. An electric / electronic component resin-sealed with the sealing material according to claim 5.

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