JP7174877B1 - Two-component curable polyurethane resin composition - Google Patents

Abstract

An object of the present invention is to achieve both moist heat resistance and tensile elongation. A two-component curable polyurethane resin composition according to one embodiment includes a first component containing a polyol and a terpene resin, and a second component containing a polyisocyanate. The polyol contains 40% by mass or more of polybutadiene polyol and/or hydrogenated polybutadiene polyol, and further contains 5 to 40% by mass of (meth)acrylic polyol. The content of the terpene resin is 3 to 60 parts by mass with respect to 100 parts by mass of the polyol. [Selection figure] None

Description

TECHNICAL FIELD The present invention relates to a two-component curable polyurethane resin composition, electrical and electronic components using the same, and a polyol composition for the two-component curable polyurethane resin composition.

Conventionally, for example, electronic circuit boards and electronic parts are sealed with a polyurethane resin composition in order to protect them from external factors, and it is known that polybutadiene polyol is used as the polyol of the polyurethane resin composition. It is

For example, in Patent Document 1, in a two-component curable polyurethane resin composition containing a first component containing a polyol and a second component containing a polyisocyanate, a polybutadiene polyol is used as the polyol, and a castor oil-based polyol is added. It is also stated that Patent Document 1 also discloses that a terpene resin is used together with polybutadiene polyol in the first component, thereby improving the compatibility of the first component and producing a polyurethane having high adhesion to a substrate and a low dielectric constant. It is stated that a resin is obtained.

Japanese Patent No. 6916404

Upon further investigation of the two-component curing type polyurethane resin composition described in Patent Document 1, it was found that it was not sufficient in terms of resistance to moist heat. In order to improve the resistance to moist heat, it was found that the tensile elongation of the cured product may be greatly reduced depending on the compounding, while changing the polyol used in combination with the polybutadiene polyol.

In view of the above points, an object of the embodiments of the present invention is to provide a two-part curable polyurethane resin composition that achieves both moist heat resistance and tensile elongation.

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 contains 40% by mass or more of polybutadiene polyol and/or hydrogenated polybutadiene polyol, and the polyol is A two-pack curable polyurethane resin composition further comprising 5 to 40% by mass of (meth)acrylic polyol, and containing 3 to 60 parts by mass of the terpene resin relative to 100 parts by mass of the polyol.
[2] The two-part curable polyurethane resin composition according to [1], wherein the polyol further contains 4 to 15% by mass of an alkylene polyol having 7 to 9 carbon atoms.
[3] The two-component curable polyurethane resin composition according to [1] or [2], which is for sealing electrical and electronic parts.
[4] An electric/electronic component resin-sealed using the two-component curing type polyurethane resin composition according to [1] or [2].
[5] A polyol composition used as a polyol component of a two-component curable polyurethane resin composition, comprising a polyol and a terpene resin, wherein the polyol contains polybutadiene polyol and/or hydrogenated polybutadiene polyol in an amount of 40% by mass or more. , The polyol composition, wherein the polyol further contains 5 to 40% by mass of (meth)acrylic polyol, and the content of the terpene resin is 3 to 60 parts by mass based on 100 parts by mass of the polyol.

According to the embodiment of the present invention, it is possible to provide a two-pack curable polyurethane resin composition that achieves both moist heat resistance and tensile elongation.

The two-part 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). Polyol (A) includes polybutadiene polyol (A1-1) and/or hydrogenated polybutadiene polyol (A1-2), and (meth)acrylic polyol (A2).

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

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), it is more preferable to use polybutadiene polyol (A1-1) from the viewpoint of tensile strength.

[(Meth) acrylic polyol (A2)]
The polyol (A) contained in the first component contains the (meth)acrylic polyol (A2) together with the PB polyol (A1). Addition of the (meth)acrylic polyol (A2) can improve wet heat resistance while maintaining good tensile elongation.

(Meth)acrylic polyol (A2) is an acrylic polymer having a plurality of hydroxy groups. The (meth)acrylic polyol (A2) is a homopolymer or copolymer of a (meth)acrylic monomer having a hydroxy group, or another monomer having a polymerizable unsaturated bond in a (meth)acrylic monomer having a hydroxy group. are exemplified by copolymerization.

As used herein, "(meth)acrylic polyol" means acrylic polyol and/or methacrylic polyol. A "(meth)acrylic monomer" means an acrylic monomer and/or a methacrylic monomer. "(Meth)acrylic acid" means acrylic acid and/or methacrylic acid. "(Meth)acrylamide" means acrylamide and/or methacrylamide.

Examples of (meth)acrylic monomers having a hydroxy group include 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, and 3 (meth)acrylate. -Hydroxypropyl, hydroxyalkyl (meth)acrylic acid esters such as 4-hydroxybutyl (meth)acrylate, (meth)acrylic acid monoesters of glycerin, triols such as (meth)acrylic acid monoesters of trimethylolpropane ( meth)acrylic acid monoester and the like. Any one of these may be used, or two or more thereof may be used in combination.

Other monomers having a polymerizable unsaturated bond include, for example, methyl (meth)acrylate, ethyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, (meth)acrylic acid Alkyl (meth)acrylates such as isobutyl, n-hexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, 2-methoxyethyl (meth)acrylate, 2-ethoxyethyl (meth)acrylate, (meth)acrylate ) alkoxyalkyl (meth)acrylates such as 3-methoxybutyl acrylate; unsaturated carboxylic acids such as (meth)acrylic acid, maleic acid and itaconic acid; saturated amide, styrene, vinyl toluene, vinyl acetate, acrylonitrile and the like. These may be used alone or in combination of two or more. Among these, (meth)acrylates such as alkyl (meth)acrylates and/or alkoxyalkyl (meth)acrylates are preferably used.

The (meth)acrylic polyol (A2) may have a hydroxyl value of, for example, 10 to 200 mgKOH/g, 20 to 180 mgKOH/g, 50 to 150 mgKOH/g, or 80 to 130 mgKOH/g.

The (meth)acrylic polyol (A2) may have a weight average molecular weight (Mw) of, for example, 1,000 to 30,000, 1,200 to 10,000, 1,500 to 5,000, or 1,800 to 3,000. In the present specification, the weight average molecular weight is determined by a GPC apparatus using tetrahydrofuran (THF) as a solvent and calculated as a polystyrene equivalent value. Specific measurement conditions are as follows.
Column: polystyrene gel column manufactured by Showa Denko (SHODEX GPC KF-601 + SHODEX GPC KF-602 + SHODEX GPC KF-603 + SHODEX GPC KF-604 connected in series in this order)
・Column temperature: 40°C
・ Detector: Differential refractive index detector (RI-504 manufactured by Showa Denko Co., Ltd.)
• Flow rate: 0.6 mL/min.
・Sample injection volume: 10 μL
・Sample concentration: 0.2% by mass THF solution

The (meth)acrylic polyol (A2) may be synthesized by a known polymerization method, or a commercially available product may be used. Examples of commercially available products include "ARUFON UH-2000, UH-2032, UH-2041, UH-2190" manufactured by Toagosei Co., Ltd., and the like.

[Alkylene polyol (A3)]
The polyol (A) contained in the first component may further contain an alkylene polyol (A3) having 7 to 9 carbon atoms together with the PB polyol (A1) and (meth)acrylic polyol (A2). Addition of the alkylene polyol (A3) can improve the tensile strength.

The alkylene polyol (A3) having 7 to 9 carbon atoms may be a diol having two hydroxy groups in one molecule, or may have three or more hydroxy groups, but is preferably a diol. Specific examples of the alkylene polyol (A3) having 7 to 9 carbon atoms include 1,7-heptanediol, 1,2-heptanediol, 2,3-heptanediol, 5-methyl-2,4-hexanediol, 2 -methyl-2,5-hexanediol, 2,4-dimethyl-2,4-pentanediol, 2,4-dimethyl-1,5-pentanediol, 2-ethyl-1,5-pentanediol, 2-ethyl - heptanediol such as 1,3-pentanediol; 1,8-octanediol, 1,2-octanediol, 1,3-octanediol, 1,4-octanediol, 2,4-octanediol, 2-methyl -1,2-heptanediol, 2-methyl-1,3-heptanediol, 2-methyl-2,3-heptanediol, 2-ethyl-1,2-hexanediol, 2-ethyl-1,3-hexane Diol, 2-ethyl-1,5-hexanediol, 2-ethyl-1,6-hexanediol, 2,5-dimethyl-2,5-hexanediol, 3,4-dimethyl-3,4-hexanediol, octanediol such as 2,5-dimethyl-3,4-hexanediol, 2,2,4-trimethyl-1,3-pentanediol, 2-propyl-1,2-pentanediol; 1,9-nonanediol, 1,2-nonanediol, 2-methyl-1,8-octanediol, 2-ethyl-1,4-heptanediol, 2,6-dimethyl-3,5-heptanediol, 2,6-dimethyl-2, nonanediol such as 6-heptanediol, 2,4-diethyl-1,5-pentanediol and 2-butyl-2-ethyl-1,3-propanediol; Any one of these may be used, or two or more thereof may be used in combination.

A branched alkylene diol is preferred as the alkylene polyol (A3). Branched alkylenediols are alkylenediols having tertiary and/or quaternary carbon atoms in the molecule. More preferably, a diol having a tertiary carbon atom in the molecule and a hydroxy group bonded to a primary carbon atom and a hydroxy group bonded to a primary or secondary carbon atom is used. is. Examples of such diols include 2,4-dimethyl-1,5-pentanediol, 2-ethyl-1,5-pentanediol, 2-ethyl-1,3-pentanediol, 2-methyl-1,3 -heptanediol, 2-ethyl-1,3-hexanediol, 2-ethyl-1,5-hexanediol, 2-ethyl-1,6-hexanediol, 2,2,4-trimethyl-1,3-pentane diol, 2-methyl-1,8-octanediol, 2-ethyl-1,4-heptanediol, 2,4-diethyl-1,5-pentanediol and the like. Any one of these may be used, or two or more thereof may be used in combination.

[Polyol (A)]
Polyol (A) may be composed only of PB polyol (A1) and (meth)acrylic polyol (A2), or may be composed only of PB polyol (A1), (meth)acrylic polyol (A2) and alkylene polyol (A3). may be composed and may contain other polyols (A4) in addition to these. The polyol (A) may be composed only of bifunctional ones, or may contain trifunctional or higher functional ones. It preferably contains a tri- or higher functional polyol to make it thermosetting.

The other polyol (A4) is a compound having multiple hydroxy groups in the molecule, and includes various polyols other than PB polyol (A1), (meth)acrylic polyol (A2) and alkylene polyol (A2). Specific examples include polyether polyols, polyester polyols, polycarbonate polyols, dimer acid polyols, polycaprolactone polyols, castor oil-based polyols, polyisoprene polyols, and hydrogenated polyisoprene polyols. In addition, low-molecular-weight polyols commonly used as cross-linking agents, such as N,N-bis(2-hydroxypropyl)aniline, hydroquinone-bis(β-hydroxyethyl)ether, resorcinol-bis(β-hydroxyethyl)ether aromatic alcohols such as

The content of the PB polyol (A1) in 100% by mass of the polyol (A) is 40% by mass or more, more preferably 50% by mass or more, still more preferably 60% by mass or more, and still more preferably 70% by mass. % by mass or more. When the content of the PB polyol (A1) is 40% by mass or more, it is possible to improve the adhesion to an electronic circuit board and the like, and to lower the dielectric constant. The content of the PB polyol (A1) is 95% by mass or less, preferably 90% by mass or less, more preferably 85% by mass or less, and may be 80% by mass or less.

The content of (meth)acrylic polyol (A2) in 100% by mass of polyol (A) is 5 to 40% by mass. When the content of the (meth)acrylic polyol (A2) is 5% by mass or more, moist heat resistance and tensile elongation can be improved, and when it is 40% by mass or less, the compatibility of the first component decline can be suppressed. The content of (meth)acrylic polyol (A2) is preferably 10% by mass or more, more preferably 12% by mass or more. The content of the (meth)acrylic polyol (A2) is preferably 35% by mass or less, more preferably 30% by mass or less, and may be 25% by mass or less.

When the polyol (A) contains the alkylene polyol (A3), the content of the alkylene polyol (A3) in 100% by mass of the polyol (A) is preferably 4 to 15% by mass. When the content of the alkylene polyol (A3) is 4% by mass or more, the tensile strength can be improved, and when it is 15% by mass or less, a decrease in compatibility with the first component can be suppressed. The content of the alkylene polyol (A3) may be 5% by mass or more, preferably 12% by mass or less, more preferably 10% by mass or less.

[Terpene resin (B)]
The first component contains a terpene resin (B) together with a PB polyol (A1) and a (meth)acrylic polyol (A2). Since the terpene resin (B) has excellent compatibility with the PB polyol (A1), separation and turbidity of the first component can be suppressed. Moreover, by blending the terpene resin (B) together with the PB polyol (A1) and the (meth)acrylic polyol (A2), it is possible to achieve both wet heat resistance and tensile elongation. In addition, it is possible to improve adhesion to an electronic circuit board or the like, which leads to maintenance or improvement of low dielectric properties.

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.

The content of the terpene resin (B) is 3 to 60 parts by mass with respect to 100 parts by mass of the polyol (A). When the content of the terpene resin (B) is 60 parts by mass or less, bleeding of the terpene resin (B) after curing of the polyurethane resin can be suppressed. 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, and even more preferably 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.

The plasticizer is not particularly limited, and examples thereof include phthalates, adipates, phosphates, trimellitates, polyester plasticizers, and acrylic plasticizers. As the plasticizer, it is preferable to use an acrylic plasticizer, which can reduce the viscosity of the first component. The content of the plasticizer is not particularly limited, and may be, for example, 30 parts by mass or less, or 5 to 20 parts by mass with respect to 100 parts by mass of the polyol (A).

<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, modified products 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). By using the aromatic polyisocyanate (C1), the effect of improving the tensile properties can be enhanced. More preferably, the polyisocyanate (C) is at least one selected from the group consisting of diphenylmethane diisocyanate, its modified form and polynuclear form.

The content of the polyisocyanate (C) in the two-component curable polyurethane resin composition is not particularly limited. or 5 to 40 parts by mass.

The polyisocyanate (C) may be composed only of bifunctional ones, or may contain trifunctional or higher functional ones. It preferably contains a tri- or higher functional polyisocyanate to make it thermosetting.

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. The first component and the second component filled in separate containers may be mixed at the time of use to form a polyurethane resin by reacting the polyol (A) and the polyisocyanate (C), which may be cured. 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, may be liquid before curing, or may be cured.

<Polyol composition>
A polyol composition according to one embodiment is used as a polyol component of a two-part curable polyurethane resin composition, and the first component corresponds to this. Therefore, the polyol composition contains a polyol (A) and a terpene resin (B), the polyol (A) contains 40% by mass or more of polybutadiene polyol and/or hydrogenated polybutadiene polyol (A1), and the polyol (A ) further contains 5 to 40% by mass of (meth)acrylic polyol (A2), and the content of terpene resin (B) is 3 to 60 parts by mass based on 100 parts by mass of polyol (A). The polyol (A) may further contain 4 to 15% by mass of an alkylene polyol (A2) having 7 to 9 carbon atoms. The details of the polyol (A), the terpene resin (B) and other components are as described above, and their description is omitted.

<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.

[PB polyol (A1)]
・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

[(Meth) acrylic polyol (A2)]
・ (Meth) acrylic polyol 1: hydroxyl value 120 mgKOH / g, weight average molecular weight 2500, product name: ARUFON UH-2041, Toagosei Co., Ltd. ・ (meth) acrylic polyol 2: hydroxyl value 110 mgKOH / g, weight average molecular weight 2000, product name: ARUFON UH-2032, manufactured by Toagosei Co., Ltd.

[Alkylene polyol (A3)]
Alkylene polyol 1: 2-ethyl-1,3-hexanediol, product name: octanediol, manufactured by KH Neochem Co., Ltd. Alkylene polyol 2: 2,4-diethyl-1,5-pentanediol, product name: Kyowa Diol PD-9, manufactured by KH Neochem Co., Ltd.

[Other polyols]
・ Castor oil-based polyol: hydroxyl value 160 mgKOH/g, product name: castor oil, manufactured by Ito Oil Co., Ltd. ・ Polyester polyol: hydroxyl value 56 mgKOH/g, product name: Kuraray Polyol P-2010, manufactured by Kuraray 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

[Other ingredients]
・ Acrylic plasticizer: acrylic polymer, weight average molecular weight 1600, product name: ARUFON UP-1021, manufactured by Toagosei Co., Ltd.

[Examples 1 to 16 and Comparative Examples 1 to 6]
According to the formulations (parts by weight) shown in Tables 1 to 3 below, two-component curable polyurethane resin compositions of each example and each comparative example were prepared. For the preparation, a predetermined amount of the first component shown in Tables 1 to 3 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 to 3, and the mixture was stirred and mixed to degas.

In Tables 1 to 3, the values in parentheses for the formulations of terpene resin 1 and terpene resin 2 indicate the amounts of active ingredients.

Tensile strength, tensile elongation, dielectric constant, adhesion, compatibility, and moist heat resistance were measured and evaluated for each two-pack curable polyurethane resin composition. The measurement and evaluation methods are as follows.

[Tensile strength, tensile elongation]
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 punched into a dumbbell-shaped No. 3 mold to obtain a sample for measurement. The measurement was performed using an apparatus manufactured by Shimadzu Corporation (main body model: AG-X Plus, name: Shimadzu Precision Universal Testing Machine Autograph), with the tensile speed set to 500 mm/min and the distance between chucks set to 40 mm. The test was performed three times, 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 2.5 MPa or more and less than 3.0 MPa C: Tensile strength is 2.0 MPa or more and less than 2.5 MPa D: Tensile strength is 1.5 MPa or more and 2.0 MPa Less than E: Tensile strength less than 1.5 MPa

(Evaluation criteria for tensile elongation)
A: Elongation is 130% or more B: Elongation is 110% or more and less than 130% C: Elongation is 90% or more and less than 110% D: Elongation is 70% or more and less than 90% E: Elongation is 70 %Less than

[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. Cohesive failure was defined as the state in which the polyurethane resin part remained on the substrate, and interfacial peeling was defined as the state in which the polyurethane resin peeled off from the substrate. Evaluation was performed according to the standard.
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 performed using a device manufactured by Espec Co., Ltd. (body model: EHS-212M, name: highly accelerated life test device), and the weight of the sample before and after the durability test at a temperature of 121 ° C. and a humidity of 85%. was measured, the weight loss rate was calculated by the following formula, and evaluated according to the following criteria.
Weight reduction rate [%] = - (M2 - M1) / M1 x 100
M1: Sample weight before the start of durability test M2: Sample weight after 200 hours of durability test A: Weight reduction rate is 4% or less B: Weight reduction rate is greater than 4% and 5% or less C: Weight reduction rate is greater than 5% Largely 6% or less D: Weight reduction rate is greater than 6% and 7% or less E: Weight reduction rate is greater than 7%, or resin melting

The results are shown in Tables 1-3. In Comparative Example 1, 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, but (meth)acrylic polyol (A2 ), the tensile strength and moist heat resistance were poor. In Comparative Example 2, since the terpene resin (B) was not blended, the tensile elongation and adhesion were inferior. Comparative Example 3 was inferior in tensile elongation because the amount of the PB polyol (A1) blended was small. In Comparative Example 4, since the compatibility of the first component was poor and the first component was separated, other evaluations could not be performed. In Comparative Examples 5 and 6, instead of the (meth)acrylic polyol (A2), a castor oil-based polyol or a polyester polyol was used, resulting in poor wet heat resistance.

On the other hand, in Examples 1 to 16 in which the PB polyol (A1), the (meth)acrylic polyol (A2), and the terpene resin (B) were used in combination, the tensile elongation significantly decreased compared to Comparative Example 1. The resistance to heat and humidity was improved while suppressing it, and it was possible to achieve both resistance to heat and humidity and tensile elongation. In addition, the adhesiveness, low dielectric properties, tensile strength, and compatibility of the first component were also found to be at or above practical levels. In Examples 1 to 12 and 16 in which the alkylene polyol (A3) was further added, an improvement in tensile strength was observed as compared to Examples 13 to 15 in which the alkylene polyol (A3) was not blended.

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 (5)

a first component comprising a polyol and a terpene resin;
a second component comprising a polyisocyanate;
The polyol contains 50% by mass or more of polybutadiene polyol and/or hydrogenated polybutadiene polyol,
The polyol further contains 5 to 40% by mass of (meth)acrylic polyol having a weight average molecular weight of 1000 to 5000 ,
A two-component curable polyurethane resin composition, wherein the content of the terpene resin is 3 to 60 parts by mass with respect to 100 parts by mass of the polyol. 2. The two-part curable polyurethane resin composition according to claim 1, wherein the polyol further contains 4 to 15% by mass of an alkylene polyol having 7 to 9 carbon atoms. 3. The two-pack curable polyurethane resin composition according to claim 1, which is used for encapsulating electrical and electronic parts. An electric/electronic component resin-sealed using the two-component curable polyurethane resin composition according to claim 1 or 2. A polyol composition used as a polyol component of a two-component curable polyurethane resin composition,
including polyols and terpene resins,
The polyol contains 50% by mass or more of polybutadiene polyol and/or hydrogenated polybutadiene polyol,
The polyol further contains 5 to 40% by mass of (meth)acrylic polyol having a weight average molecular weight of 1000 to 5000 ,
The polyol composition, wherein the content of the terpene resin is 3 to 60 parts by mass with respect to 100 parts by mass of the polyol.