Polyol composition, two-component curable polyurethane resin composition, and cured object

Abstract

Provided is a polyol composition which has excellent storage stability and with which it is possible to obtain a cured object in which an excessive increase in elastic modulus at low temperatures can be suppressed while having a high elastic modulus at room temperature. Also provided is a two-component curable polyurethane resin composition.　A polyol composition according to an embodiment is a composition to be reacted with a polyisocyanate to obtain a polyurethane resin, and contains a polybutadiene polyol, a trifunctional polyether polyol, an ether-ester plasticizer, and a phthalate ester plasticizer.

Description

Polyol composition, two-component curable polyurethane resin composition, and cured product

[0001] Embodiments of the present invention relate to a polyol composition, a two-component curable polyurethane resin composition using the polyol composition, and a cured product thereof.

[0002] A two-component curable polyurethane resin composition comprising a first liquid containing a polyol and a second liquid containing a polyisocyanate is used in various applications, such as for electric and electronic parts.

[0003] For example, Patent Document 1 discloses a first liquid containing, as a polyol, a polybutadiene polyol and a polyether polyol obtained by adding an alkylene oxide containing propylene oxide and / or butylene oxide to an active hydrogen compound having 3 to 6 functional groups, and a second liquid containing a polyisocyanate.

[0004] Japanese Patent No. 7209890

[0005] In some cases, depending on the application, the cured product of the two-component curable polyurethane resin composition is required to have moisture and heat resistance. Also, for the cured product, it may be required to have a high elastic modulus at room temperature while suppressing an excessive increase in the elastic modulus at low temperatures. In order to meet such requirements, the present inventor has devised to use a polybutadiene polyol and a trifunctional polyether polyol in combination as the polyol. However, it has been found that when a polybutadiene polyol and a trifunctional polyether polyol are used in combination, the compatibility is poor and the storage stability of the polyol composition as the first liquid is impaired.

[0006] In view of the above points, an embodiment of the present invention aims to provide a polyol composition capable of obtaining a cured product that can suppress an excessive increase in the elastic modulus at low temperatures while having a high elastic modulus at room temperature, and having excellent storage stability, and a two-component curable polyurethane resin composition comprising the polyol composition.

[0007] The present invention includes the embodiments shown below. [1] A polyol composition for obtaining a polyurethane resin by reacting with a polyisocyanate, comprising a polybutadiene polyol, a trifunctional polyether polyol, an ether ester plasticizer, and a phthalate ester plasticizer. [2] The polyol composition according to [1], wherein the mass ratio of the polybutadiene polyol to the trifunctional polyether polyol is 1 / 1 to 5 / 1. [3] The polyol composition according to [1] or [2], wherein the mass ratio of the ether ester plasticizer to the phthalate ester plasticizer is 1 / 3 to 3 / 1. [4] The polyol composition according to any one of [1] to [3], wherein the number average molecular weight of the trifunctional polyether polyol is 1500 or less. [5] The polyol composition according to any one of [1] to [4], wherein the trifunctional polyether polyol comprises a polyether polyol obtained by adding an alkylene oxide containing 70 mol% or more of propylene oxide to an active hydrogen compound having 3 functional groups. [6] A two-component curable polyurethane resin composition comprising a first liquid containing a polyol and a second liquid containing a polyisocyanate, wherein the first liquid is the polyol composition described in any one of [1] to [5]. [7] The two-component curable polyurethane resin composition according to [6] for use in electrical and electronic components. [8] A cured product obtained by curing the two-component curable polyurethane resin composition according to [6] or [7].

[0008] According to embodiments of the present invention, a cured product can be obtained that has a high elastic modulus at room temperature while suppressing an excessive increase in the elastic modulus at low temperatures, and that also has excellent storage stability. A polyol composition and a two-component curable polyurethane resin composition can be provided.

[0009] The two-component curable polyurethane resin composition according to this embodiment comprises a first liquid containing a polyol (A) and a second liquid containing a polyisocyanate (B). The polyol composition according to this embodiment is used as the first liquid and contains a polybutadiene polyol (A1), a trifunctional polyether polyol (A2), an ether ester plasticizer (C1), and a phthalate ester plasticizer (C2), and a polyurethane resin is obtained by reacting it with the polyisocyanate (B).

[0010] <Polyol Composition> [Polybutadiene Polyol (A1)] Polybutadiene polyol (A1) is a polybutadiene having hydroxyl groups, and is a non-hydrogenated (i.e., not hydrogenated) polybutadiene polyol. Preferably, polybutadiene polyol (A1) has a polybutadiene structure in which 1,4-bonded, 1,2-bonded, or a mixture thereof are present in the molecule, and at least two hydroxyl groups, and more preferably, a polybutadiene structure with hydroxyl groups at both ends.

[0011] The number-average molecular weight (Mn) of polybutadiene polyol (A1) is not particularly limited, but is preferably 700 to 5000, more preferably 1000 to 4000, and may also be 1500 to 3800, 2000 to 3500, or 2500 to 3300.

[0012] In this specification, the number-average molecular weight (Mn) is measured by GPC (gel permeation chromatography) and calculated using a calibration curve with standard polystyrene. Specifically, 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 volume: 50 μL; Sample concentration: 0.2% by mass.

[0013] The hydroxyl value of polybutadiene polyol (A1) is not particularly limited, but is preferably 10 to 200 mg KOH / g, more preferably 15 to 150 mg KOH / g, even more preferably 20 to 120 mg KOH / g, and may also be 25 to 100 mg KOH / g, 30 to 90 mg KOH / g, or 35 to 70 mg KOH / g.

[0014] In this specification, the hydroxyl value is measured in accordance with Method A of JIS K1557-1:2007.

[0015] [Trifunctional Polyether Polyol (A2)] Trifunctional polyether polyol (A2) is a polyether polyol having multiple ether bonds in its molecule and having three hydroxyl groups. Preferably, the trifunctional polyether polyol (A2) is obtained by adding an alkylene oxide to an active hydrogen compound having three functional groups.

[0016] The above-mentioned active hydrogen compound having three functional groups is a compound having three active hydrogen atoms that can be added to an alkylene oxide, i.e., a compound having three active hydrogen atoms in one molecule. Examples of such active hydrogen compounds include polyhydric alcohols and alkanolamines. Examples of polyhydric alcohols include trihydric alcohols such as glycerin, trimethylolpropane, trimethylolethane, butanetriol, and hexanetriol. Examples of alkanolamines include ethanolamine, diethanolamine, triethanolamine, methanolamine, and isopropanolamine. These active hydrogen compounds may be used individually or in combination of two or more.

[0017] Examples of alkylene oxides to be added to the active hydrogen compound include ethylene oxide, propylene oxide, and butylene oxide, and these may be used individually or in combination of two or more.

[0018] Such alkylene oxide adducts can be produced by using the above-mentioned active hydrogen compound with three functional groups as a starting material (initiator) and carrying out a ring-opening addition reaction of alkylene oxide to the starting material in the presence of a catalyst.

[0019] The number-average molecular weight (Mn) of the trifunctional polyether polyol (A2) is preferably 1500 or less, which can further increase the elastic modulus at room temperature. More preferably, the number-average molecular weight of the trifunctional polyether polyol (A2) is 300 to 1200, more preferably 300 to 1000, and even more preferably 350 to 700.

[0020] The hydroxyl value of the trifunctional polyether polyol (A2) is not particularly limited and may be, for example, 100-600 mg KOH / g, 140-500 mg KOH / g, or 200-450 mg KOH / g.

[0021] In one embodiment, it is preferable to use a polyether polyol (A2-1) obtained by adding an alkylene oxide containing 70 mol% or more of propylene oxide to an active hydrogen compound having three functional groups as the trifunctional polyether polyol (A2). In this way, by having 70 mol% or more of the total alkylene oxide units constituting the polyether polyol be propylene oxide units, the compatibility with polybutadiene polyol (A1) can be improved. The alkylene oxide preferably contains 80 mol% or more of propylene oxide, more preferably 90 mol% or more, and even more preferably 100 mol%.

[0022] The trifunctional polyether polyol (A2) preferably contains 50% by mass or more of the polyether polyol (A2-1), more preferably 70% by mass or more, and even more preferably 90% by mass or more, and may even contain 100% by mass.

[0023] [Polyol (A)] Polyol (A) may consist only of polybutadiene polyol (A1) and trifunctional polyether polyol (A2), or it may also contain other polyols (A3) in addition to these.

[0024] Other polyols (A3) are compounds having multiple hydroxyl groups in their molecule and include various polyols other than polybutadiene polyols (A1) and trifunctional polyether polyols (A2). Specifically, these include polyester polyols, polycarbonate polyols, dimer acid polyols, castor oil polyols, polycaprolactone polyols, acrylic polyols, polyisoprene polyols, hydrogenated polyisoprene polyols, hydrogenated polybutadiene polyols, and difunctional polyether polyols. Low molecular weight polyols commonly used as crosslinking agents are also acceptable, such as polyhydric alcohols with a molecular weight of less than 300, specifically aliphatic alcohols such as ethylene glycol, 1,4-butanediol, octanediol, trimethylolpropane, triisopropanolamine, and octanediol, and aromatic alcohols such as N,N-bis(2-hydroxypropyl)aniline, hydroquinone-bis(β-hydroxyethyl) ether, and resorcinol-bis(β-hydroxyethyl) ether.

[0025] In polyol (A), the mass ratio (A1) / (A2) of polybutadiene polyol (A1) to trifunctional polyether polyol (A2) is preferably 1 / 1 to 5 / 1. A mass ratio (A1) / (A2) of 5 / 1 or less (i.e., 5 or less) makes it easier to increase the proportion of trifunctional polyether polyol (A2) and maintain a high modulus of elasticity at room temperature. A mass ratio (A1) / (A2) of 1 / 1 or more (i.e., 1 or more) makes it easier to increase the proportion of polybutadiene polyol (A1) and suppress the increase in modulus of elasticity at low temperatures. A mass ratio (A1) / (A2) is preferably 5 / 4 to 4 / 1, more preferably 3 / 2 to 7 / 2, and even more preferably 9 / 5 to 3 / 1.

[0026] The content of polybutadiene polyol (A1) in 100% by mass of polyol (A) is not particularly limited, but is preferably 50% by mass or more, more preferably 55 to 83% by mass, more preferably 60 to 80% by mass, and even more preferably 65 to 75% by mass.

[0027] The content of trifunctional polyether polyol (A2) in 100% by mass of polyol (A) is not particularly limited, but is preferably 50% by mass or less, more preferably 18 to 45% by mass, more preferably 20 to 40% by mass, and even more preferably 25 to 35% by mass.

[0028] The total amount of polybutadiene polyol (A1) and trifunctional polyether polyol (A2) in 100% by mass of polyol (A) is preferably 70% by mass or more, more preferably 80% by mass or more, more preferably 90% by mass or more, and even more preferably 100% by mass.

[0029] The amount of polyol (A) in the polyol composition is not particularly limited, and may be 5 to 90% by mass, 6 to 75% by mass, 7 to 40% by mass, 8 to 30% by mass, 9 to 25% by mass, or 10 to 20% by mass in 100% by mass of the polyol composition.

[0030] [Ether ester plasticizer (C1)] Ether ester plasticizer (C1) is a plasticizer containing a polyether structure and an ester structure. Examples of ether ester plasticizer (C1) include ester compounds of polyalkylene glycol and monocarboxylic acid, and ester compounds of polyalkylene glycol and polycarboxylic acid. The polyalkylene glycol preferably contains polyethylene glycol as the main component (preferably 80 mol% or more).

[0031] Examples of ester compounds of polyalkylene glycol and monocarboxylic acid include aliphatic polyether ester plasticizers such as aliphatic carboxylic acid monoester compounds of polyalkylene glycol and aliphatic carboxylic acid diester compounds of polyalkylene glycol. In the case of the monoester compound, for example, it may be an ester compound obtained by reacting an aliphatic monocarboxylic acid with a polyethylene glycol monoalkyl ether, which is obtained by adding an aliphatic alcohol to one end of polyethylene glycol. Specific examples of aliphatic polyether ester plasticizers include polyethylene glycol butanoate, polyethylene glycol isobutanoate, polyethylene glycol (2-ethylhexanoic acid) ester, polyethylene glycol decanoate, polyethylene glycol dibutanoate, polyethylene glycol diisobutanoate, polyethylene glycol di(2-ethylbutyric acid) ester, polyethylene glycol di(2-ethylhexanoic acid) ester, and polyethylene glycol didecanoate ester. Any one of these may be used, or two or more may be used in combination.

[0032] As ester compounds of polyalkylene glycol and polycarboxylic acid, ester compounds obtained by reacting polyethylene glycol monoalkyl ether, which is obtained by adding an aliphatic alcohol to one end of polyethylene glycol, with an aliphatic dicarboxylic acid may also be used. Specific examples of ester compounds of polyalkylene glycol and polycarboxylic acid include adipic acid ether ester plasticizers such as dibutoxyethanol adipate, di(butyl diglycol) adipate, di(butyl polyglycol) adipate, di(2-ethylhexyloxyethanol) adipate, di(2-ethylhexyl diglycol) adipate, di(2-ethylhexyl polyglycol) adipate, dioctoxyethanol adipate, di(octyl diglycol) adipate, and di(octyl polyglycol) adipate. Any one of these may be used, or two or more may be used in combination.

[0033] The molecular weight of the ether ester plasticizer (C1) is not particularly limited; for example, the molecular weight or number average molecular weight (Mn) may be 300 to 2000, 350 to 1000, or 400 to 900.

[0034] Examples of commercially available ether ester plasticizers (C1) include polyether ester plasticizers such as "ADEKA Sizer RS-700," "ADEKA Sizer RS-735," "ADEKA Sizer RS-966," and "ADEKA Sizer RS-1000" (all manufactured by ADEKA Corporation). Examples of commercially available adipic acid ether ester plasticizers include "ADEKA Sizer RS-107" (manufactured by ADEKA Corporation).

[0035] [Phthalate ester plasticizer (C2)] Examples of phthalate ester plasticizers (C2) include dibutyl phthalate, diisobutyl phthalate, diheptyl phthalate, di(2-ethylhexyl) phthalate, di-n-octyl phthalate, dinonyl phthalate, diisononyl phthalate, diisodecyl phthalate, diundecyl phthalate, ditridecyl phthalate, dicyclohexyl phthalate, diphenyl phthalate, ethyl benzyl phthalate, butyl benzyl phthalate, isobutyl benzyl phthalate, heptyl benzyl phthalate, (2-ethylhexyl) benzyl phthalate, n-octyl benzyl phthalate, nonyl benzyl phthalate, isononyl benzyl phthalate, isodecyl benzyl phthalate, undecyl benzyl phthalate, tridecyl benzyl phthalate, cyclohexyl benzyl phthalate, benzyl-3-(isobutyryloxy)-1-isopropyl-2,2-dimethylpropyl phthalate, myristyl benzyl phthalate, and the like. You may use one of these individually, or you may use two or more in combination.

[0036] In one embodiment, the phthalate ester plasticizer (C2) is preferably a dialkyl phthalate, more preferably a diester of an alkanol having 4 to 18 carbon atoms and phthalic acid, and even more preferably a diester of an alkanol having 6 to 15 carbon atoms and phthalic acid.

[0037] [Plasticizer (C)] In this embodiment, an ether ester-based plasticizer (C1) and a phthalate ester-based plasticizer (C2) are used in combination as the plasticizer (C). This improves the compatibility of the polyol composition containing polybutadiene polyol (A1) and trifunctional polyether polyol (A2), thereby improving the storage stability of the polyol composition. Furthermore, in combination with using polybutadiene polyol (A1) and trifunctional polyether polyol (A2) as the polyol (A), a cured product can be obtained that has a high elastic modulus at room temperature while suppressing an excessive increase in the elastic modulus at low temperatures. It is preferable that the plasticizer (C) consists only of an ether ester-based plasticizer (C1) and a phthalate ester-based plasticizer (C2), but other plasticizers may be used in combination as long as the purpose of this embodiment is not impaired.

[0038] The mass ratio (C1) / (C2) of the ether ester plasticizer (C1) to the phthalate ester plasticizer (C2) is preferably 1 / 3 to 3 / 1, which can enhance the compatibility improvement effect of the polyol composition. The mass ratio (C1) / (C2) is preferably 2 / 5 to 5 / 2, more preferably 1 / 2 to 2 / 1, and even more preferably 2 / 3 to 3 / 2.

[0039] The total amount of ether ester plasticizer (C1) and phthalate ester plasticizer (C2) per 100 parts by mass of polyol (A) is not particularly limited, but from the viewpoint of further enhancing the effects of this embodiment, it is preferably 40 to 180 parts by mass, more preferably 50 to 150 parts by mass, more preferably 60 to 130 parts by mass, more preferably 70 to 125 parts by mass, and even more preferably 80 to 115 parts by mass.

[0040] [Other Components] In addition to the components described above, various additives such as catalysts, fillers, active hydrogen compounds other than polyols, antioxidants, foam stabilizers, defoamers, diluents, flame retardants, ultraviolet absorbers, colorants, fillers, and plasticizers may be added to the polyol composition as needed, to the extent that they do not impair the purpose of this embodiment.

[0041] As the catalyst, those that promote the reaction between the polyol (A) and the polyisocyanate (B) are used. For example, metal catalysts such as organotin catalysts, organolead catalysts, and organobismuth catalysts, various urethane polymerization catalysts such as amine catalysts, and organic acid catalysts such as octylic acid can be mentioned. The amount of the catalyst is not particularly limited. For example, it may be 0.001 to 0.02 parts by mass, or 0.005 to 0.01 parts by mass, based on 100 parts by mass of the polyol (A).

[0042] As the filler, an inorganic filler is preferred. Examples of the inorganic filler include metal oxides such as silica, alumina, and magnesium oxide, metal hydroxides such as aluminum hydroxide and magnesium hydroxide, and metal nitrides such as aluminum nitride and boron nitride. The amount of the filler is not particularly limited. In one embodiment, when the polyol composition contains a filler, the amount of the filler (preferably an inorganic filler) in 100% by mass of the polyol composition may be, for example, 20 to 92% by mass, 50 to 90% by mass, 60 to 85% by mass, or 65 to 80% by mass.

[0043] The polyol composition is a liquid at room temperature (25°C), that is, a liquid composition having fluidity, and its viscosity is not particularly limited.

[0044] <Two-component curable polyurethane resin composition> The two-component curable polyurethane resin composition is formed by combining a first liquid containing the polyol (A) and a second liquid containing the polyisocyanate (B), and a polyurethane resin is formed by mixing and reacting the two. Therefore, it is also referred to as a two-component polyurethane-forming composition.

[0045] [First liquid] As the first liquid, the above polyol composition is used.

[0046] [Second Liquid] The polyisocyanate (B) contained in the second liquid is not particularly limited, and various polyisocyanate compounds having two or more isocyanate groups in one molecule can be used. For example, as the polyisocyanate (B), aromatic polyisocyanate (B1), aliphatic polyisocyanate (B2), and alicyclic polyisocyanate (B3) can be mentioned, and any one of these may be used alone or two or more of them may be used in combination.

[0047] Examples of the aromatic polyisocyanate (B1) include 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 compounds thereof.

[0048] Examples of the aliphatic polyisocyanate (B2) include 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 compounds thereof.

[0049] Examples of the alicyclic polyisocyanate (B3) include isophorone diisocyanate (IPDI), hydrogenated xylylene diisocyanate, 4,4'-dicyclohexylmethane diisocyanate, 1,4-cyclohexane diisocyanate, methylcyclohexylene diisocyanate, 1,3-bis(isocyanatomethyl)cyclohexane, and modified products and polynuclear compounds thereof.

[0050] Examples of the above-mentioned modified products include isocyanurate modified products, allophanate modified products, burette modified products, adduct modified products, carbodiimide modified products, and the like.

[0051] In one embodiment, the polyisocyanate (B) preferably includes an aromatic polyisocyanate (B1). More preferably, the polyisocyanate (B) is at least one selected from the group consisting of diphenylmethane diisocyanate (MDI), its modified forms, and polynuclear forms (B11). The amount of (B1), preferably (B11), in 100% by mass of polyisocyanate (B) is preferably 50% by mass or more, more preferably 80% by mass or more, and may be 100% by mass.

[0052] The amount of polyisocyanate (B) in the two-component curable polyurethane resin composition is not particularly limited, and may be 5 to 70 parts by mass, 10 to 60 parts by mass, or 15 to 50 parts by mass per 100 parts by mass of polyol (A).

[0053] The NCO / OH (index) is not particularly limited and may be, for example, 0.60 to 1.60, 0.70 to 1.50, 0.80 to 1.40, or 0.90 to 1.30.

[0054] Here, NCO / OH is the molar ratio of isocyanate groups in polyisocyanate (B) to hydroxyl groups 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 using the isocyanate content measured in accordance with Method A of JIS K1603-1:2007, using the formula: Isocyanate value = {(Isocyanate content) × 56110} / (42.02 × 100).

[0055] In one embodiment, the second liquid may contain a plasticizer (D) together with the polyisocyanate (B). The plasticizer (D) contained in the second liquid is preferably an ether ester plasticizer (C1) and / or a phthalate ester plasticizer (C2) contained in the first liquid (polyol composition), and more preferably a phthalate ester plasticizer (C2). However, other plasticizers may be used.

[0056] If the second liquid contains a plasticizer (D), the amount is not particularly limited and may be 10 to 300 parts by mass, 50 to 250 parts by mass, or 80 to 200 parts by mass per 100 parts by mass of polyisocyanate (B).

[0057] The second liquid may consist only of polyisocyanate (B), or it may consist of polyisocyanate (B) and a plasticizer (D), or, if necessary, various additives such as catalysts, fillers, antioxidants, foam stabilizers, defoamers, diluents, flame retardants, ultraviolet absorbers, colorants, fillers, and plasticizers may be added together, to the extent that the purpose of this embodiment is not impaired.

[0058] The second liquid is liquid, or fluid, at room temperature (25°C), and its viscosity is not particularly limited.

[0059] The two-component curable polyurethane resin composition according to this embodiment is usually composed of the first liquid and the second liquid described above, but it may also include a third liquid containing the other components described above as an optional component, in addition to the first and second liquids.

[0060] A two-component curable polyurethane resin composition can be manufactured by preparing a first liquid and a second liquid separately, and the first and second liquids may be provided separately. That is, it may be a two-component kit in which the first and second liquids are filled in separate containers. When the first and second liquids, which are filled in separate containers, are mixed at the time of use, the polyol (A) and polyisocyanate (B) react to produce a polyurethane resin, and a cured polyurethane resin product is obtained as the reaction product. That is, a cured product obtained by curing a two-component curable polyurethane resin composition is obtained. In this case, curing may be done by heating or by curing at room temperature. The heating temperature and heating time are not particularly limited.

[0061] <Applications of the Two-Component Curable Polyurethane Resin Composition> The applications of the two-component curable polyurethane resin composition according to this embodiment are not particularly limited. For example, it may be used as a resin material that constitutes part of an electrical and electronic component, for example, for sealing electrical and electronic components. Examples of electrical and electronic components include transformers such as transformer coils, choke coils and reactor coils, equipment control boards, sensors, and wireless communication components.

[0062] The present invention will be described in more detail below based on examples and comparative examples, but it is not limited thereto.

[0063] Details of each component used in the examples and comparative examples are as follows.

[0064] [Polyols] ・Polybutadiene polyol 1: Hydroxyl value 47 mg KOH / g, number average molecular weight approximately 2900, product name "POLYVEST-HT", manufactured by Evonik ・Polybutadiene polyol 2: Hydroxyl value 102.7 mg KOH / g, number average molecular weight approximately 1200, product name "Poly bd R-15HT", manufactured by Idemitsu Kosan Co., Ltd. ・Polyether polyol 1: Trifunctional, hydroxyl value 420 mg KOH / g, number average molecular weight approximately 400, product name "EXCENOL 430", manufactured by AGC Inc. ・Polyether polyol 2: Trifunctional, hydroxyl value 160 mg KOH / g, number average molecular weight approximately 1000, product name "EXCENOL "1030", manufactured by AGC Inc., polyether polyol 3: difunctional, hydroxyl value 280 mg KOH / g, product name "EXCENOL 420", manufactured by AGC Inc., polyester polyol: trifunctional, hydroxyl value 336 mg KOH / g, product name "Kuraray Polyol F-510", manufactured by Kuraray Co., Ltd.

[0065] [Plasticizers] ・Ether ester plasticizer 1: Product name "ADEKA Sizer RS-700", manufactured by ADEKA Corporation ・Ether ester plasticizer 2: Product name "ADEKA Sizer RS-966", manufactured by ADEKA Corporation ・Ether ester plasticizer 3: Product name "MONOSizer W-260", manufactured by DIC Corporation ・Phthalate ester plasticizer 1: Diisononyl phthalate (DINP) ・Phthalate ester plasticizer 2: Diundecyl phthalate (DUP) ・Phosphorus plasticizer: Product name "Sanso Sizer TCP", manufactured by Shin Nippon Rika Co., Ltd.

[0066] [Polyisocyanates] ・HDI Isocyanurate 1: Isocyanate content 23.3%, product name "Duranate TLA-100", manufactured by Asahi Kasei Corporation ・HDI Isocyanurate 2: Isocyanate content 23.1%, product name "Duranate TPA-100-D", manufactured by Asahi Kasei Corporation ・Polymeric MDI: Isocyanate content 32%, product name "Foamlight NE-5000B", manufactured by BASF INOAC Polyurethane Co., Ltd.

[0067] [Other components] ・Tin-based catalyst: Product name "Neostan U-810", manufactured by Nitto Kasei Co., Ltd. ・Inorganic filler: Product name "Suisanka Aluminum C305-F", manufactured by Sumitomo Chemical Co., Ltd.

[0068] [Examples 1-17 and Comparative Examples 1-7] Two-component curable polyurethane resin compositions for each example and comparative example were prepared according to the formulations (parts by mass) shown in Tables 1-4 below. Specifically, the first and second liquids were prepared by weighing each component according to the formulations shown in Tables 1-4 and then stirring and mixing them. The compatibility of the obtained first liquid (polyol composition) was evaluated. The evaluation method is as follows.

[0069] The first and second liquids were stirred and mixed according to the "mass ratio of the first liquid to the second liquid" shown in Tables 1 to 4, and then degassed. The degassed mixture was poured into a 3 mm thick mold and cured at 80°C for one day to produce a 3 mm thick resin sheet. The heat resistance to moisture, and the elastic modulus at room temperature and low temperature were measured using the obtained resin sheet. The measurement method is as follows.

[0070] [Compatibility] Each component of the first liquid was weighed, and the appearance of the first liquid after stirring and mixing was observed and its compatibility was evaluated according to the following criteria. A: It was transparent and did not separate even after one week. B: It was transparent and did not separate after mixing, but separated after one week. C: It separated immediately after mixing.

[0071] [Heat and Humidity Resistance] Resin sheets were cut into 30mm x 30mm x 3mm sheets to be used as measurement samples. Measurements were performed using an ESPEC Corporation device (model: EHS-212M, name: Advanced Accelerated Life Testing Device). In unsaturated control (humidified water temperature control) mode, the condition of the resin sheet was observed after a predetermined time in a durability test at a temperature of 85°C and humidity of 85%, and the time until the resin melted and could no longer maintain its sheet shape was measured and evaluated according to the following criteria. For samples with a compatibility evaluation of "C", it was not possible to produce a resin sheet, and measurement was not possible. A: 3000 hours or more B: 2500 hours or more but less than 3000 hours C: Less than 2500 hours D: Not measurable

[0072] [Modulus of Elasticity] Resin sheets were cut into sheets measuring 5 mm wide x 30 mm long x 3 mm thick to serve as measurement samples. Dynamic viscoelasticity measurements were performed using a dynamic viscoelasticity measuring instrument manufactured by UBM Co., Ltd. (model: Rheogel E-4000), with the deformation mode set to tensile mode. The modulus of elasticity was measured and evaluated according to the following criteria. For the tensile mode, the chuck distance was set to 20 mm, the initial strain to 0.2 mm, and a sinusoidal force with a frequency of 10 Hz and strain amplitude of 2 μm was applied to the measurement sample. The measurement temperatures were 25°C and -40°C. Samples with a compatibility evaluation of "C" could not be measured because it was not possible to produce resin sheets.

[0073] (Room temperature: 25°C) A: 25 MPa or higher B: 10 MPa or higher but less than 25 MPa C: Less than 10 MPa D: Measurement impossible

[0074] (Low temperature: -40°C) A: Less than 500 MPa B: 500 MPa or more and less than 2000 MPa C: 2000 MPa or more D: Measurement impossible

[0075]

[0076]

[0077]

[0078]

[0079] The results are shown in Tables 1 to 4. Comparative Example 1 was a combination of polybutadiene polyol and a difunctional polyether polyol, which had poor resistance to humid heat and low modulus of elasticity at room temperature, and failed to meet the required properties. Comparative Example 2 was a combination of polybutadiene polyol and a trifunctional polyester polyol, which had a high modulus of elasticity at room temperature and suppressed an excessive increase in modulus of elasticity at low temperatures, but had poor resistance to humid heat.

[0080] Comparative Example 3, because the polyol was a polybutadiene polyol alone and did not contain a trifunctional polyether polyol, had a low modulus of elasticity at room temperature and could not meet the required properties. Comparative Example 4, because the polyol was a trifunctional polyether polyol alone and did not contain a polybutadiene polyol, had a modulus of elasticity at low temperatures that was too high and could not meet the required properties.

[0081] Comparative Examples 5 to 7 used polybutadiene polyol and trifunctional polyether polyol as the polyol, but did not use ether ester-based plasticizers and phthalate ester-based plasticizers in combination. In Comparative Examples 5 to 7, separation was observed immediately after mixing the first solution, indicating poor compatibility of the first solution. Therefore, it was not possible to measure the heat resistance to moisture and the modulus of elasticity.

[0082] In contrast, Examples 1 to 17 used a combination of polybutadiene polyol and trifunctional polyether polyol as the polyol, and a combination of ether ester-based plasticizer and phthalate ester-based plasticizer as the plasticizer, resulting in excellent compatibility of the first liquid and excellent storage stability. Furthermore, the cured product exhibited excellent resistance to humid heat, a high modulus of elasticity at room temperature, and suppressed an excessive increase in the modulus of elasticity at low temperatures.

[0083] Furthermore, the various numerical ranges described in this specification can be any combination of their upper and lower limits, and all such combinations are described herein as preferred numerical ranges. Also, the description of a numerical range as "X to Y" means X or greater and Y or less.

[0084] 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, and modifications are included in the scope and spirit of the invention, as well as in the claims and their equivalents.

Claims

1. A polyol composition for obtaining a polyurethane resin by reacting with a polyisocyanate, comprising a polybutadiene polyol, a trifunctional polyether polyol, an ether ester plasticizer, and a phthalate ester plasticizer.

2. The polyol composition according to claim 1, wherein the mass ratio of the polybutadiene polyol to the trifunctional polyether polyol is 1 / 1 to 5 / 1.

3. The polyol composition according to claim 1, wherein the mass ratio of the ether ester plasticizer to the phthalate ester plasticizer is 1 / 3 to 3 / 1.

4. The polyol composition according to claim 1, wherein the number average molecular weight of the trifunctional polyether polyol is 1500 or less.

5. The polyol composition according to claim 1, wherein the trifunctional polyether polyol comprises a polyether polyol obtained by adding an alkylene oxide containing 70 mol% or more of propylene oxide to an active hydrogen compound having three functional groups.

6. A two-component curable polyurethane resin composition comprising a first liquid containing a polyol and a second liquid containing a polyisocyanate, wherein the first liquid is the polyol composition according to any one of claims 1 to 5.

7. The two-component curable polyurethane resin composition according to claim 6, for use in electrical and electronic components.

8. A cured product obtained by curing the two-component curable polyurethane resin composition described in claim 6.

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