JP7209890B1 - Two-component curable polyurethane resin composition - Google Patents

Abstract

An object of the present invention is to achieve both adhesion and moist heat resistance. A two-component curable polyurethane resin composition according to an embodiment includes a first component containing a polyol and a terpene resin, and a second component containing a polyisocyanate. The polyol is polybutadiene polyol and/or hydrogenated polybutadiene polyol, and a polyether polyol obtained by adding an alkylene oxide containing propylene oxide and/or butylene oxide in an amount of 70 mol% or more to an active hydrogen-containing compound having a functionality of 3 to 6, including. For the cured product obtained by mixing the first component and the second component, 120 ° C. obtained by dynamic viscoelasticity measurement in tensile mode at a frequency of 10 Hz, a strain amplitude of 0.01%, and a heating rate of 3 ° C./min. The storage modulus at is 2.0 to 7.0 MPa. [Selection figure] None

Description

TECHNICAL FIELD The present invention relates to a two-pack curable polyurethane resin composition, a cured product thereof, and electrical and electronic components using the composition.

Conventionally, for example, electronic circuit boards and electronic components are sealed with a polyurethane resin composition in order to protect them from external factors. It is known to use polybutadiene polyol as the polyol for such polyurethane resin compositions.

For example, Patent Document 1 describes a two-component curable polyurethane resin composition containing a first component containing a polyol containing polybutadiene polyol and a terpene resin, and a second component containing a polyisocyanate. According to Patent Document 1, it is described that by using a terpene resin together with polybutadiene polyol, the compatibility is improved, the adhesion to substrates and the like is improved, and a polyurethane resin with a low dielectric constant is obtained.

Japanese Patent No. 6916404

The two-pack curable polyurethane resin composition as described above is sometimes required to have moisture and heat resistance in its cured product depending on the application. It has been found that a two-pack curable polyurethane resin composition using a combination of polybutadiene polyol and a terpene resin has adhesion to substrates and the like, but is sometimes insufficient in moist heat resistance.

An object of an embodiment of the present invention is to provide a two-pack curable polyurethane resin composition that achieves both adhesion and moist heat resistance.

The present invention includes embodiments shown below.
[1] A first component containing a polyol and a terpene resin, and a second component containing a polyisocyanate, wherein the polyol is a polybutadiene polyol and/or a hydrogenated polybutadiene polyol, and an active hydrogen-containing group having 3 to 6 functional groups. A polyether polyol obtained by adding an alkylene oxide containing propylene oxide and/or butylene oxide in an amount of 70 mol% or more to a compound, and a cured product obtained by mixing the first component and the second component. , a frequency of 10 Hz, a strain amplitude of 0.01%, and a temperature rise rate of 3 ° C. / min. type polyurethane resin composition.
[2] The two-pack curable polyurethane resin composition according to [1], wherein the polyether polyol has a number average molecular weight of 300 to 2,000.
[3] The two-part curable polyurethane resin composition according to [1] or [2], wherein the polyisocyanate contains an aromatic polyisocyanate.
[4] The two-part curable polyurethane resin composition according to any one of [1] to [3], wherein the polyol further contains a castor oil-based polyol.
[5] The two-component curable polyurethane resin composition according to any one of [1] to [4], which is used for encapsulating electrical and electronic parts.
[6] A cured product obtained by curing the two-component curable polyurethane resin composition according to any one of [1] to [5].
[7] An electric/electronic component resin-sealed with the two-part curable polyurethane resin composition according to any one of [1] to [5].

According to the embodiment of the present invention, it is possible to provide a two-component curable polyurethane resin composition that can achieve both adhesion to substrates and the like and resistance to moist heat.

The two-component curable polyurethane resin composition according to this embodiment includes a first component containing polyol (A) and terpene resin (B), and a second component containing polyisocyanate (C). Further, the polyol (A) is a polybutadiene polyol (A1-1) and/or a hydrogenated polybutadiene polyol (A1-2), and an alkylene containing propylene oxide and/or butylene oxide in an active hydrogen-containing compound having 3 to 6 functional groups. It contains a polyether polyol (A2) to which an oxide is added. A cured product obtained by mixing the first component and the second component has a storage elastic modulus at 120° C. of 2.0 to 7.0 MPa.

According to this embodiment, by using the polybutadiene polyol (A1-1) and/or the hydrogenated polybutadiene polyol (A1-2) together with the terpene resin (B), the adhesion to the substrate or the like can be improved. . In addition, by blending the trifunctional or higher polyether polyol (A2), the storage elastic modulus of the cured product at 120°C can be increased, and the storage elastic modulus at 120°C can be increased by 2. Moist heat resistance can be improved by setting the pressure to 0 MPa or more. Therefore, both adhesion and resistance to moist heat can be achieved. The reason why the moisture and heat resistance is improved by increasing the storage modulus of the cured product at 120°C is not necessarily clear, and although it is not intended to be limited by this, the storage modulus at 120°C is high. This means that cross-linking by the polyether polyol (A2) increases, which is considered to extend the time until the polyurethane resin melts in a moist heat environment.

The storage elastic modulus is the dynamic viscoelasticity of the cured product obtained by mixing the first component and the second component in a tensile mode at a frequency of 10 Hz, a strain amplitude of 0.01%, and a heating rate of 3 ° C./min. It is a storage modulus at 120°C obtained by measurement. A detailed measurement method is as described in Examples.

The method for making the storage modulus at 120° C. of the cured product in the range of 2.0 to 7.0 MPa is not particularly limited. For example, increasing the blending amount of the polyether polyol (A2), increasing the number of functional groups and decreasing the molecular weight of the polyether polyol (A2), or reducing the blending amount of the terpene resin (B). can increase the storage modulus at 120° C. and can be adjusted within the range of 2.0 to 7.0 MPa.

The storage elastic modulus of the cured product at 120° C. is more preferably 2.5 MPa or more, still more preferably 3.0 MPa or more, still more preferably 3.5 MPa or more. The higher the storage elastic modulus at 120° C., the better the moist heat resistance. It may be 4.0 MPa or less.

<First component>
[Polybutadiene polyol (A1-1) and/or hydrogenated polybutadiene polyol (A1-2)]
The polyol (A) contained in the first component includes polybutadiene polyol (A1-1) and/or hydrogenated polybutadiene polyol (A1-2) (both may be collectively referred to as "PB polyol (A1)" hereinafter). ) is used.

Polybutadiene polyol (A1-1) is a non-hydrogenated (ie, non-hydrogenated) polybutadiene polyol. The polybutadiene polyol (A1-1) preferably has a 1,4-bonded, 1,2-bonded, or mixed polybutadiene structure in the molecule and at least two hydroxy groups, both ends of the polybutadiene structure. each having a hydroxy group is more preferred.

The hydroxyl value of the polybutadiene polyol (A1-1) may be, for example, 10-200 mgKOH/g, 15-150 mgKOH/g, or 20-120 mgKOH/g. From the viewpoint of adhesion and compatibility, the hydroxyl value of the polybutadiene polyol (A1-1) is preferably 25-100 mgKOH/g, more preferably 40-90 mgKOH/g.

As used herein, the hydroxyl value is measured according to JIS K1557-1:2007, Method A.

The hydrogenated polybutadiene polyol (A1-2) has a hydrogenated structure with respect to the polybutadiene polyol (A1-1), and some or all of the unsaturated double bonds contained in the polybutadiene polyol are water. attached. The degree of hydrogenation of the hydrogenated polybutadiene polyol (A1-2) is not particularly limited. For example, the iodine value may be 50 g/100 g or less, or 30 g/100 g or less.

As used herein, the iodine value is measured according to JIS K0070:1992.

The hydroxyl value of the hydrogenated polybutadiene polyol (A1-2) may be, for example, 10 to 200 mgKOH/g, 15 to 150 mgKOH/g, 20 to 120 mgKOH/g, 25 to 100 mgKOH/g, or 40 to 90 mgKOH. /g.

As the PB polyol (A1), either one of polybutadiene polyol (A1-1) or hydrogenated polybutadiene polyol (A1-2) may be used, or both may be used. Preferably, polybutadiene polyol (A1-1) is used.

[Polyether polyol (A2)]
To the polyol (A) contained in the first component, an alkylene oxide containing propylene oxide and/or butylene oxide in an amount of 70 mol% or more is added to an active hydrogen-containing compound having a functionality of 3 to 6 together with the PB polyol (A1). A polyether polyol (A2) consisting of

Polyether polyols (A2) are alkylene oxide adducts of active hydrogen-containing compounds. The active hydrogen-containing compound is a compound having an active hydrogen atom capable of undergoing an addition reaction with an alkylene oxide. In the present embodiment, the compound has 3 to 6 functional groups, that is, a compound having 3 to 6 active hydrogen atoms in one molecule. is used.

Examples of active hydrogen-containing compounds include polyhydric alcohols, alkanolamines, polyamines, and the like, and any one of them may be used alone, or two or more thereof may be used in combination.

Examples of polyhydric alcohols include trihydric alcohols such as glycerin, trimethylolpropane, trimethylolethane, butanetriol and hexanetriol, tetrahydric alcohols such as pentaerythritol and diglycerin, trimers of glycerin, glucose, mannose, and the like. and hexahydric alcohols such as sorbitol, mannitol, and dipentaerythritol. Any one of these may be used or two or more thereof may be used in combination.

Examples of the alkanolamine include those having three functional groups, such as ethanolamine, diethanolamine, triethanolamine, methanolamine, and isopropanolamine. Any one of these may be used or two or more thereof may be used in combination. .

Examples of polyamines include those having 4 functional groups such as ethylenediamine, tolylenediamine, diethyltoluenediamine, 1,3-propanediamine, 1,6-hexanediamine, and isophoronediamine, and those having 5 functional groups. Diethylenetriamine and the like can be mentioned as the functional group, and triethylenetetramine and the like can be mentioned as those having 6 functional groups.

The number of functional groups of the active hydrogen-containing compound is the number of functional groups of the polyether polyol (A2). When the number of functional groups is 3 or more, the storage elastic modulus of the cured product at 120°C can be improved. In addition, since the number of functional groups is 6 or less, the hydrophilicity of the polyether polyol (A2) is suppressed from becoming excessively high, and the compatibility with the PB polyol (A1) and the terpene resin (B) is improved. can be done. As the active hydrogen-containing compound, one of those having 3 to 6 functional groups may be used, or two or more of those having different numbers of functional groups may be used in combination. From the viewpoint of enhancing compatibility between compatibility and storage elastic modulus at 120° C., the active hydrogen-containing compound preferably has 3 to 4 functional groups. That is, as the active hydrogen-containing compound, one having three functional groups may be used, one having four functional groups may be used, and one having three and four functional groups may be used in combination. The number of functional groups of the active hydrogen-containing compound is more preferably 3.

Examples of the alkylene oxide to be added to the active hydrogen-containing compound include ethylene oxide, propylene oxide and butylene oxide. As the butylene oxide, 1,2-butylene oxide and/or 2,3-butylene oxide is used, preferably 1,2-butylene oxide.

In this embodiment, 70 mol % or more of the alkylene oxide added to the active hydrogen-containing compound is composed of propylene oxide and/or butylene oxide. That is, 70 mol % or more of the total alkylene oxide units constituting the polyether polyol (A2) consist of propylene oxide units, butylene oxide units, or a combination of both. By adding propylene oxide or butylene oxide as a main component to the active hydrogen-containing compound in this way, the compatibility with the PB polyol (A1) or the terpene resin (B) can be improved. The alkylene oxide preferably contains 80 mol% or more of propylene oxide and/or butylene oxide, more preferably 90 mol% or more, and still more preferably 100 mol%.

The alkylene oxide preferably contains propylene oxide. Therefore, the alkylene oxide may contain propylene oxide in an amount of 70 mol% or more, more preferably 80 mol% or more, still more preferably 90 mol% or more, still more preferably 100 mol%.

The polyether polyol (A2) can be produced by subjecting the above active hydrogen-containing compound as a starting material (initiator) to a ring-opening addition reaction of the above alkylene oxide to the starting material in the presence of a catalyst.

As the addition form of the alkylene oxide, when using a plurality of types of alkylene oxides, it may be random addition or block addition, and is not particularly limited. In one embodiment, after addition polymerization of propylene oxide and/or butylene oxide to the active hydrogen-containing compound, ethylene oxide may be added to the polymer terminal. When ethylene oxide is used together with propylene oxide and/or butylene oxide as the alkylene oxide, the alkylene oxide may be composed of 70 to 90 mol % propylene oxide and/or butylene oxide and 10 to 30 mol % ethylene oxide.

In one embodiment, the polyether polyol (A2) is an alkylene containing at least one polyhydric alcohol selected from the group consisting of trihydric alcohols and tetrahydric alcohols and 70 mol% or more of propylene oxide and/or butylene oxide. It may be one to which an oxide has been added. More specifically, the polyether polyol (A2) contains at least one selected from the group consisting of glycerin, trimethylolpropane, trimethylolethane, butanetriol, hexanetriol, pentaerythritol, and diglycerin, and the alkylene oxide may be added. More preferably, glycerin and/or diglycerin to which the above alkylene oxide (preferably alkylene oxide containing 70 mol % or more of propylene oxide) is added.

The number average molecular weight (Mn) of the polyether polyol (A2) is preferably 300-2000. When the polyether polyol (A2) has a number average molecular weight of 300 or more, compatibility with the PB polyol (A1) and the terpene resin (B) can be improved. Further, when the number average molecular weight is 2000 or less, the effect of increasing the storage elastic modulus by blending the polyether polyol (A2) can be enhanced. The number average molecular weight of the polyether polyol (A2) is more preferably 350 or more, still more preferably 400 or more, and preferably 1800 or less, more preferably 1600 or less, still more preferably 1200. or less, and may be 1000 or less.

As used herein, the number average molecular weight (Mn) is a value measured by a GPC method (gel permeation chromatography) and calculated using a standard polystyrene calibration curve. 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.

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

[Castor oil-based polyol (A3)]
The polyol (A) may further contain a castor oil-based polyol (A3). By adding the castor oil-based polyol (A3), the storage elastic modulus at 120° C. and adhesion can be improved.

As the castor oil-based polyol (A3), castor oil, castor oil fatty acid, hydrogenated castor oil obtained by hydrogenating these, and polyol produced using hydrogenated castor oil fatty acid can be used. More specifically, castor oil-based polyols (A3) include, for example, castor oil, transesterified products of castor oil and other natural oils and fats, reaction products of castor oil and polyhydric alcohols, and esterification of castor oil fatty acids and polyhydric alcohols. Examples include reactants and polyols obtained by addition polymerization of alkylene oxide thereto.

The hydroxyl value of the castor oil-based polyol (A2) is not particularly limited, and may be, for example, 50 to 250 mgKOH/g or 100 to 180 mgKOH/g.

[Polyol (A)]
The polyol (A) may be composed only of the PB polyol (A1) and the polyether polyol (A2), or composed only of the PB polyol (A1), the polyether polyol (A2) and the castor oil-based polyol (A3). may also contain other polyols (A4) in addition to these.

Other polyols (A4) are compounds having multiple hydroxy groups in the molecule, and include various polyols other than PB polyols (A1), polyether polyols (A2), and castor oil-based polyols (A3). Specific examples include polyester polyol, polycarbonate polyol, dimer acid polyol, polycaprolactone polyol, acrylic polyol, polyisoprene polyol, and hydrogenated polyisoprene polyol. Also, low-molecular-weight polyols that are generally used as cross-linking agents may be used. hydroxyethyl)ether, resorcinol-bis(β-hydroxyethyl)ether and other aromatic alcohols, ethylene glycol, 1,4-butanediol, octanediol, trimethylolpropane, triisopropanolamine, octanediol and other aliphatic alcohols. mentioned.

The content of the PB polyol (A1) in 100% by mass of the polyol (A) is not particularly limited, but is preferably 40% by mass or more, more preferably 50% by mass or more, and still more preferably 60% by mass or more. and more preferably 65% by mass or more. When the content of the PB polyol (A1) is 40% by mass or more, it is advantageous for improving the adhesion and lowering the dielectric constant. The upper limit of the content of the PB polyol (A1) is not particularly limited, and may be, for example, 97% by mass or less, 92% by mass or less, 90% by mass or less, or 85% by mass or less.

Although the content of the polyether polyol (A2) in 100% by mass of the polyol (A) is not particularly limited, it is preferably 3 to 15% by mass. The higher the content of the polyether polyol (A2), the higher the storage modulus at 120°C and the higher the moist heat resistance. Moreover, deterioration of compatibility can be suppressed by being 15 mass % or less. The content of the polyether polyol (A2) is preferably 4% by mass or more, more preferably 5% by mass or more, and is preferably 12% by mass or less, more preferably 10% by mass or less.

When the polyol (A) contains the castor oil-based polyol (A3), the content of the castor oil-based polyol (A3) in 100% by mass of the polyol (A) is not particularly limited. It may be 10 to 40% by mass, or 15 to 30% by mass.

[Terpene resin (B)]
The first component contains a terpene resin (B) together with a PB polyol (A1) and a polyether polyol (A2). The terpene resin (B) can improve adhesion to electronic circuit boards and the like. In addition, since the terpene resin (B) has excellent compatibility with the PB polyol (A1), separation and turbidity of the first component can be suppressed.

The terpene resin (B) is a polymer containing terpene as a constituent monomer. Terpenes (also referred to as terpene monomers) include, for example, α-pinene, β-pinene, limonene (including racemic dipentene), myrcene, alloocimene, ocimene, α-phellandrene, β-phellandrene, α- Monoterpenes such as terpinene, γ-terpinene, and sabinene can be mentioned, and any one of them or two or more of them 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, more preferably α-pinene, At least one selected from the group consisting of β-pinene and limonene.

Examples of the terpene resin (B) include the following (B1) to (B3).
- A polyterpene resin (B1) whose constituent monomer is a homopolymer or copolymer consisting only of a terpene monomer
- Aromatically modified terpene resin (B2) which is a copolymer of a terpene monomer and an aromatic monomer
- A terpene phenolic resin (B3) which is a copolymer of a terpene monomer and a phenolic monomer.
Any one of (B1) to (B3) may be used, or two or more of them may be used in combination.

Examples of aromatic monomers constituting the aromatic modified terpene resin (B2) include styrene, α-methylstyrene, 4-methylstyrene, 2,4-dimethylstyrene and the like.

Examples of phenol-based monomers constituting the terpene phenol resin (B3) include phenol, cresol, and xylenol.

Preferable examples of the terpene resin (B) include polyterpene resin (B1) which is at least one homopolymer or copolymer selected from the group consisting of α-pinene, β-pinene and limonene, α-pinene , Aromatic modified terpene resin (B2) which is a copolymer of at least one terpene monomer and styrene selected from the group consisting of β-pinene and limonene, α-pinene, β-pinene and limonene from the group consisting of A terpene phenol resin (B3) is a copolymer of at least one selected terpene monomer and phenol.

Although the content of the terpene resin (B) is not particularly limited, it is preferably 3 to 60 parts by mass based on 100 parts by mass of the polyol (A). The content of the terpene resin (B) is preferably 5 parts by mass or more, more preferably 10 parts by mass or more, still more preferably 12 parts by mass or more, and may be 15 parts by mass or more. The content of the terpene resin (B) is preferably 50 parts by mass or less, more preferably 40 parts by mass or less, still more preferably 35 parts by mass or less, and may be 30 parts by mass or less.

[Other ingredients]
In addition to the components described above, the first component may optionally include, for example, a catalyst, an antioxidant, a foam stabilizer, a diluent, a flame retardant, an ultraviolet absorber, a coloring agent, a filler, a plasticizer, and the like. can be added as long as the purpose of the present embodiment is not impaired.

Examples of catalysts that can be used include metal catalysts such as organotin catalysts, organolead catalysts and organobismuth catalysts, and various urethane polymerization catalysts such as amine catalysts.

<Second component>
[Polyisocyanate (C)]
The polyisocyanate (C) contained in the second component is not particularly limited, and various polyisocyanate compounds having two or more isocyanate groups in one molecule can be used. Examples of the polyisocyanate (C) include aromatic polyisocyanate (C1), aliphatic polyisocyanate (C2), and alicyclic polyisocyanate (C3). More than one species may be used in combination.

Examples of the aromatic polyisocyanate (C1) include tolylene diisocyanate (TDI, such as 2,4-TDI, 2,6-TDI), diphenylmethane diisocyanate (MDI, such as 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 these modified forms and polynuclear forms of.

Aliphatic polyisocyanates (C2) include, for example, tetramethylene diisocyanate, dodecamethylene diisocyanate, hexamethylene diisocyanate (HDI), 2,2,4-trimethylhexamethylene diisocyanate, 2,4,4-trimethylhexamethylene diisocyanate, lysine Examples include diisocyanate, 2-methylpentane-1,5-diisocyanate, 3-methylpentane-1,5-diisocyanate, and modified and polynuclear products thereof.

Examples of the alicyclic polyisocyanate (C3) include isophorone diisocyanate (IPDI), hydrogenated xylylene diisocyanate, 4,4′-dicyclohexylmethane diisocyanate, 1,4-cyclohexane diisocyanate, methylcyclohexylene diisocyanate, 1,3- Bis(isocyanatomethyl)cyclohexane, modified products thereof and polynuclear products thereof can be mentioned.

Examples of the above modified compounds include isocyanurate modified products, allophanate modified products, burette modified products, adduct modified products, carbodiimide modified products and the like.

In one embodiment, polyisocyanate (C) preferably comprises aromatic polyisocyanate (C1). Since the aromatic polyisocyanate (C1) has high reactivity, it can be used without a catalyst as an essential component. More preferably, as the polyisocyanate (C), at least one selected from the group consisting of diphenylmethane diisocyanate, its modified form and polynuclear form is used.

The content of the polyisocyanate (C) in the two-component curable polyurethane resin composition is not particularly limited. or 10 to 40 parts by mass.

The ratio of the polyisocyanate (C) and the polyol (A) is not particularly limited, for example, the NCO/OH (index) may be 0.6 to 1.5, 0.7 to 1.4, It may be 0.8 to 1.3, or 0.9 to 1.2.

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

[Other ingredients]
The second component may be composed only of polyisocyanate (C), and in addition to polyisocyanate (C), if necessary, for example, catalyst, antioxidant, foam stabilizer, diluent, flame retardant , UV absorbers, colorants, fillers, plasticizers, and other additives may be added to the extent that the purpose of the present embodiment is not impaired.

<Two-component curable polyurethane resin composition>
The two-component curable polyurethane resin composition according to the present embodiment is usually composed of the first component as the first component and the second component as the second component. In addition, a third component containing the above-mentioned other components as optional components may be provided as the third liquid.

The two-component curable polyurethane resin composition can be produced by preparing the first component and the second component, respectively. good. When the first component and the second component are mixed at the time of use, the polyol (A) and the polyisocyanate (C) react to form a polyurethane resin, which is cured to form a cured product. At that time, it 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.

<Application of two-component curing type polyurethane resin composition>
The use of the two-part curable polyurethane resin composition according to the present embodiment is not particularly limited, but it is preferably used for sealing electrical and electronic parts. 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. The two-part curable polyurethane resin composition has excellent low dielectric properties (that is, it has a low dielectric constant) and is less susceptible to radio waves. Therefore, the two-component curable polyurethane resin composition is preferably used as a sealing material for resin-sealing, that is, covering wireless communication parts for wireless communication in order to protect the wireless communication parts from the external environment. For example, it may be used as a sealing material for a sensor that transmits detected information by wireless communication.

Electrical and electronic components resin-sealed using the two-component curable polyurethane resin composition according to the present embodiment include, for example, electric washing machines, toilet seats, water heaters, water purifiers, baths, dishwashers, solar panels, Can be used for electric tools, automobiles, motorcycles, etc.

The two-pack curable polyurethane resin composition will be described in detail below based on Examples and Comparative Examples, but the present invention is not limited thereto.

Raw materials used in Examples and Comparative Examples are shown below.

[Polyol (A)]
・Polybutadiene polyol 1: hydroxyl value 47 mgKOH/g, product name: Poly bd R-45HT, manufactured by Idemitsu Kosan Co., Ltd. ・Polybutadiene polyol 2: hydroxyl value 107 mgKOH/g, product name: Poly bd R-15HT, Idemitsu Kosan Co., Ltd. ) manufactured by Hydrogenated polybutadiene polyol: hydroxyl value 49 mgKOH / g, product name: KRASOL H-LBH-2000, manufactured by Clay Valley

Polyether polyol 1: Polypropylene glycol obtained by addition polymerization of propylene oxide using glycerin as a starting material. Number average molecular weight 430, number of functional groups 3, hydroxyl value 400 mgKOH/g, amount of propylene oxide units in all alkylene oxide units 100 mol%, product name: EXCENOL430, manufactured by AGC Co., Ltd.

Polyether polyol 2: Polypropylene glycol obtained by addition polymerization of propylene oxide using glycerin as a starting material. Number average molecular weight 700, functional number 3, hydroxyl value 240 mgKOH/g, amount of propylene oxide units in all alkylene oxide units 100 mol%, product name: ADEKA POLYETHER G700, manufactured by ADEKA Corporation

Polyether polyol 3: Polypropylene glycol obtained by addition polymerization of propylene oxide using diglycerin as a starting material. Number average molecular weight 750, number of functional groups 4, hydroxyl value 300 mgKOH/g, amount of propylene oxide units in all alkylene oxide units 100 mol%, product name: SC-P750, manufactured by Sakamoto Yakuhin Kogyo Co., Ltd.

Polyether polyol 4: Polypropylene glycol obtained by addition polymerization of propylene oxide using diglycerin as a starting material. Number average molecular weight 1000, functional group number 4, hydroxyl value 230 mgKOH/g, amount of propylene oxide units in all alkylene oxide units 100 mol%, product name: SC-P1000, manufactured by Sakamoto Yakuhin Kogyo Co., Ltd.

・ Castor oil-based polyol: hydroxyl value 160 mgKOH / g, product name: castor oil, manufactured by Ito Oil Co., Ltd.

[Terpene resin (B)]
・ Terpene resin 1: limonene-styrene copolymer, active ingredient 50% by mass, product name: YS Resin LP, manufactured by Yasuhara Chemical Co., Ltd. ・ Terpene resin 2: pinene-dipentene copolymer, active ingredient 80% by mass, product name : Dymaron, manufactured by Yasuhara Chemical Co., Ltd. Terpene resin 3: Phenol/α-pinene copolymer, active ingredient 100% by mass, product name: YS POLYSTER T80, manufactured by Yasuhara Chemical Co., Ltd.

[Polyisocyanate (C)]
・ Aromatic polyisocyanate: Polymeric MDI, product name: Millionate MR-200, manufactured by Tosoh Corporation

[Examples 1 to 14 and Comparative Examples 1 to 3]
Two-component curable polyurethane resin compositions of each example and each comparative example were prepared according to the formulations (parts by mass) shown in Tables 1 and 2 below. For the preparation, a predetermined amount of the first component shown in Tables 1 and 2 was weighed, and stirred and mixed while being melted by heating appropriately. After mixing, the temperature was adjusted to 25°C. Subsequently, the second component (polyisocyanate (C)) adjusted to 25° C. was added to the mixture as shown in Tables 1 and 2, and the mixture was stirred and mixed to degas.

In Tables 1 and 2, the values in parentheses for the formulations of terpene resin 1 and terpene resin 2 indicate the formulation amounts as active ingredients.

The storage elastic modulus at 120° C. was measured for each two-pack curable polyurethane resin composition. In addition, dielectric constant, adhesion, compatibility and resistance to moist heat were measured and evaluated for each two-part curable polyurethane resin composition. The measurement and evaluation methods are as follows.

[Storage modulus at 120°C]
The defoamed two-pack curable polyurethane resin composition was poured into a mold having a thickness of 3 mm and cured at 80° C. for 16 hours (overnight) to prepare a resin sheet having a thickness of 3 mm. The resin sheet was cut into sheets of width 5 mm×length 30 mm×thickness 3 mm to obtain samples for measurement. Dynamic viscoelasticity measurement is performed by using a dynamic viscoelasticity measuring instrument manufactured by UBM Co., Ltd. (body type: Rheogel E-4000), measuring the elastic modulus with the deformation mode as the tensile mode, and storing at 120 ° C. The value of elastic modulus E' was determined. As the measurement conditions, the distance between chucks was 20 mm, the initial strain was 0.2 mm (1%), and a sine wave force with a frequency of 10 Hz and a strain amplitude of 2 μm (0.01%) was applied to the measurement sample. rice field. The measurement temperature was -100° C. to 150° C., and the rate of temperature increase was 3° C./min.

[Permittivity]
The defoamed two-pack curable polyurethane resin composition was poured into a mold having a thickness of 3 mm and cured at 80° C. for 16 hours (overnight) to prepare a resin sheet having a thickness of 3 mm. The resin sheet was cut into sheets of 50 mm×50 mm×3 mm to obtain samples for measurement. The measurement was performed using an apparatus manufactured by Agilent Technologies, Inc. (body model: E4980A, name: Precision LCR Meter, electrode part model: 16451B, name: DIELECTRIC TEST FIXTURE), and the dielectric constant at a frequency of 1 MHz (relative dielectric constant) was measured and evaluated according to the following criteria.
A: permittivity is 2.8 or less B: permittivity is greater than 2.8 and 3.0 or less C: permittivity is greater than 3.0 and 3.2 or less D: permittivity is greater than 3.2 and 3.4 Below E: Dielectric constant greater than 3.4

[Adhesion]
On a commercially available FR-4 epoxy substrate, the degassed two-pack curable polyurethane resin composition was dropped about 1 cm in diameter, cured at 80° C. for 16 hours (overnight) and cured. Aiming at the boundary between the cured polyurethane resin and the epoxy substrate, the resin was scraped off with a cutter knife, and the polyurethane resin remaining on the substrate was visually confirmed. For the evaluation, "cohesive failure" is the state in which the polyurethane resin part remains on the substrate, and "interfacial peeling" is the state in which the polyurethane resin is peeled off from the substrate. Evaluation was performed according to the following criteria. In addition, if the evaluation is D or higher, it can be said to have practical adhesion.
A: 100% cohesive failure
B: Cohesive failure is 75% or more and less than 100%, interfacial peeling is more than 0% and less than 25% C: Cohesive failure is 50% or more and less than 75%, interfacial peeling is more than 25% and 50% or less D: Cohesive failure is 25% or more Less than 50%, more than 50% and 75% or less of interfacial delamination E: Less than 25% of cohesive failure, 75% or more of interfacial delamination

[Compatibility]
The state of the liquid after mixing the first component was confirmed, and the compatibility of the first component was evaluated according to the following criteria. In the case of D and E, other evaluations were not carried out because they were separated.
A: Transparent B: Slightly turbid C: Turbid D: Separation occurred after 30 minutes or more E: Separation occurred in less than 30 minutes

[Damp heat resistance]
The defoamed two-pack curable polyurethane resin composition was poured into a mold having a thickness of 3 mm and cured at 80° C. for 16 hours (overnight) to prepare a resin sheet having a thickness of 3 mm. The resin sheet was cut into sheets of 30 mm×30 mm×3 mm to obtain samples for measurement. The measurement was carried out using an apparatus manufactured by ESPEC Co., Ltd. (main body type: EHS-212M, name: highly accelerated life test apparatus), in the unsaturated control (humidification water temperature control) mode, at a temperature of 121 ° C. The state of the resin sheet was checked after a predetermined period of time in the durability test at 85% humidity, and the time until the resin melted and the sheet shape could no longer be maintained was measured, and evaluated according to the following criteria.
A: 500 hours or more B: 400 hours or more and less than 500 hours C: 300 hours or more and less than 400 hours D: 200 hours or more and less than 300 hours E: Less than 200 hours

The results are shown in Tables 1 and 2. In Comparative Example 3, the combined use of the PB polyol (A1) and the terpene resin (B) resulted in excellent compatibility, low dielectric properties, and excellent adhesion to the substrate. Since it was not compounded and the storage elastic modulus at 120°C was low, the wet heat resistance was poor. In Comparative Example 1, the PB polyol (A1) and the polyether polyol (A2) were used in combination, and the storage modulus at 120°C was high. Therefore, the adhesion to the substrate was poor. In Comparative Example 2, the PB polyol (A1) and the terpene resin (B) were used in combination, and the polyether polyol (A2) was further blended. rice field.

On the other hand, PB polyol (A1), polyether polyol (A2) and terpene resin (B) are blended, and the storage elastic modulus at 120 ° C. is within the specified range. While maintaining the practical adhesion to, the wet heat resistance was improved compared to Comparative Examples 2 and 3, and both the adhesion and the wet heat resistance were achieved. Further, Examples 1 to 14 had practical compatibility and were excellent in low dielectric properties.

It should be noted that the various numerical ranges described in the specification can be arbitrarily combined with their upper and lower limits, and all combinations thereof are described in this specification as preferred numerical ranges. Further, the description of the numerical range "X to Y" means X or more and Y or less.

Although several embodiments of the invention have been described above, these embodiments are presented by way of example and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, replacements, and modifications can be made without departing from the scope of the invention. These embodiments, their omissions, replacements, modifications, etc., are included in the invention described in the scope of claims and equivalents thereof, as well as being included in the scope and gist of the invention.

Claims (6)

a first component comprising a polyol and a terpene resin;
a second component comprising a polyisocyanate;
The polyol is a polybutadiene polyol and/or a hydrogenated polybutadiene polyol, and an active hydrogen-containing compound having a functional number of 3 to 6 and an alkylene oxide containing propylene oxide and/or butylene oxide in an amount of 70 mol% or more is added to have a number average molecular weight of a polyether polyol that is between 300 and 1200 ;
120 by dynamic viscoelasticity measurement in tensile mode at a frequency of 10 Hz, a strain amplitude of 0.01%, and a heating rate of 3 ° C./min for the cured product obtained by mixing the first component and the second component. The storage modulus at ° C. is 2.0 to 7.0 MPa,
A two-component curable polyurethane resin composition. 2. The two-part curable polyurethane resin composition according to claim 1, wherein said polyisocyanate comprises an aromatic polyisocyanate. 2. The two-part curable polyurethane resin composition according to claim 1, wherein said polyol further contains a castor oil-based polyol. 4. The two-component curable polyurethane resin composition according to any one of claims 1 to 3 , which is used for encapsulating electrical and electronic parts. A cured product obtained by curing the two-component curable polyurethane resin composition according to any one of claims 1 to 3 . An electric/electronic component resin-sealed with the two-component curing type polyurethane resin composition according to any one of claims 1 to 3 .