JP6678903B2 - Polyurethane resin composition for electrical insulation - Google Patents

Description

  The present invention relates to a polyurethane resin composition for electrical insulation.

  In recent years, due to the progress of electronic circuit boards and electronic components, stress on members has been increased due to cooling and heating cycles, and members having high heat resistance, high humidity resistance, and low temperature flexibility have been demanded.

  The polyurethane resin used for these encapsulations has a problem that it loses flexibility due to a long-term cooling / heating cycle and cracks occur, and the temperature dependence of the elastic modulus can be further reduced, and the member can be retained for a long time. Development is urgent.

  Further, in recent years, due to the miniaturization of components, there is a problem that the clearance between the substrate and the case is narrow and the resin does not flow in properly.

  For example, Patent Document 1 describes a polyurethane resin electric insulation composition containing a polybutadiene-based polyol and a castor oil-based polyol.

  In this polyurethane resin electric insulating composition, it is considered that the castor oil-based polyol is blended for the purpose of lowering the viscosity, but when the castor oil-based polyol amount is increased, the low temperature elastic modulus is increased and the heat cycle property is lowered. There was a problem that

JP, 2009-67818, A

  An object of the present invention is to provide a polyurethane resin which is excellent in compatibility and workability and can maintain high heat resistance, high humidity resistance, and low temperature flexibility.

  The present inventor has conducted extensive studies to solve the above problems, and as a result, a polyurethane resin composition containing (A) a polyisocyanate compound and (B) a polyol compound, wherein the (B) polyol compound is: It has been found that the above problems can be solved by using a polyurethane resin composition containing (B1) a polyfarnesene polyol compound and (B2) a polybutadiene-based polyol compound and / or (B3) a castor oil-based polyol. The present invention has been completed based on such findings.

  That is, the present invention relates to the following polyurethane resin composition, encapsulant, electric / electronic component and the like.

Item 1.
A polyurethane resin composition containing (A) a polyisocyanate compound and (B) a polyol compound,
The (B) polyol compound is (B1) a polyfarnesene polyol compound, and
A polyurethane resin composition containing (B2) a polybutadiene-based polyol compound and / or (B3) a castor oil-based polyol.
Item 2.
Item 2. The polyurethane according to Item 1, wherein the blending ratio of the (B1) polyfarnesene polyol compound to the (B2) polybutadiene polyol compound and / or (B3) castor oil-based polyol is 10 to 90:90 to 10. Resin composition.
Item 3.
Item 3. The blending ratio of the (B1) polyfarnesene polyol compound to the (B2) polybutadiene polyol compound and / or (B3) castor oil-based polyol is 10 to 70:90 to 30. Polyurethane resin composition.
Item 4.
Item 4. The polyurethane resin composition according to any one of Items 1 to 3, wherein the (B) polyol compound is a (B1) polyfarnesene polyol compound and a (B2) polybutadiene-based polyol compound.
Item 5.
Item 5. The polyurethane resin composition according to any one of Items 1 to 4, wherein the number average molecular weight (Mn) of the (B1) polyfarnesene polyol compound is in the range of 100 to 5000.
Item 6.
Item 6. The polyurethane resin composition according to any one of Items 1 to 5, wherein the polyfarnesene polyol (B1) has a viscosity (25 ° C) in the range of 1 mPa · s to 100 Pa · s.
Item 7.
Item 7. The polyurethane resin composition according to any one of Items 1 to 6, wherein the glass transition temperature (30 ° C) of the (B1) polyfarnesene polyol is in the range of -100 to 0 ° C.
Item 8.
Item 8. The polyurethane resin composition according to any one of Items 1 to 7, wherein the (B2) polybutadiene-based polyol compound is a polybutadiene polyol having a hydroxyl value of 60 mgKOH / g or less.
Item 9.
Item 9. The polyurethane resin composition according to any one of Items 1 to 8, wherein the number average molecular weight (Mn) of the (B2) polybutadiene-based polyol compound is in the range of 100 to 5000.
Item 10.
Item 10. The polyurethane resin composition according to any one of items 1 to 9, which is used for sealing electrical and electronic parts.
Item 11.
Item 11. A sealing material comprising the polyurethane resin composition according to any one of items 1 to 10.
Item 12.
An electric / electronic component resin-sealed using the sealing material according to item 11.

  INDUSTRIAL APPLICABILITY The present invention can provide a polyurethane resin composition and a sealing material which are excellent in compatibility and workability and can retain high heat resistance, high moisture resistance, and low temperature flexibility.

  Specifically, the polyurethane resin composition and the encapsulant of the present invention can maintain low-temperature flexibility (elastic modulus) (-20 ° C to -40 ° C) and suppress changes in elastic modulus. Further, the polyol compound used in the present invention has excellent compatibility at high temperature, and the polyurethane resin composition and the sealing material obtained by using the same have excellent volume resistivity, elongation (flexibility), and tensile strength. It exhibits strength, dielectric breakdown resistance and moisture resistance, and is also excellent in hardness due to thermal deterioration (after heat resistance).

  Therefore, the polyurethane resin composition of the present invention can be suitably used, for example, for insulation treatment of various electric and electronic parts.

  Furthermore, since the electric / electronic component of the present invention is resin-sealed with the above-mentioned sealing material, it exhibits high reliability.

  The polyurethane resin composition, sealing material and electric / electronic component of the present invention will be described in detail below. In the present specification, the expression "containing" or "comprising" includes the concepts of "containing", "including", "consisting essentially of" and "consisting solely of".

1. Polyurethane Resin Composition The polyurethane resin composition of the present invention is a polyurethane resin composition containing (A) polyisocyanate compound and (B) polyol compound,
The (B) polyol compound contains (B1) a polyfarnesene polyol compound, and (B2) a polybutadiene-based polyol compound and / or (B3) a castor oil-based polyol.

1-1. The (A) polyisocyanate compound “(A) polyisocyanate compound” is not particularly limited as long as it has two or more isocyanate groups, and is a polyurethane resin composition (particularly, a polyurethane resin composition for encapsulating electric and electronic parts). It is possible to use various kinds of components used in or that can be used.

  The polyisocyanate compound (A) is not particularly limited, and examples thereof include polyisocyanate compounds such as aliphatic polyisocyanate compounds, alicyclic polyisocyanate compounds, aromatic polyisocyanate compounds, and araliphatic polyisocyanate compounds; polyisocyanate compounds. (For example, isocyanurate body, carbodiimide body, adduct body, biuret body, allophanate body, etc.), polyisocyanate compound polynuclear body and the like.

  Among these, from the viewpoint that the heat resistance and the hydrolysis resistance can be further improved, (A1) isocyanurate body of polyisocyanate compound (more preferably isocyanurate body of aliphatic polyisocyanate compound) is mentioned. To be In addition to these preferred polyisocyanates, the polyisocyanate (A) is further (A2) a polynuclear compound of a polyisocyanate compound (A2) from the viewpoint that the dielectric constant can be further lowered (that is, the electrical characteristics can be further improved). It is desirable to contain a polynuclear body of an aromatic polyisocyanate compound. In this case, in addition to the polynuclear body (A2) of the polyisocyanate compound, the polyisocyanate compound (A) can further lower the dielectric loss tangent (that is, further improve the electrical characteristics), and thus (A3) ) It may contain a carbodiimide body of a polyisocyanate compound (preferably, a carbodiimide body of an aromatic polyisocyanate compound).

  Examples of the aliphatic polyisocyanate compound include tetramethylene diisocyanate, dodecamethylene diisocyanate, 1,6-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 the like, and hexamethylene diisocyanate (HDI) is preferable.

  As the isocyanurate-modified hexamethylene diisocyanate used in the present invention, a polyisocyanate having an isocyanurate group having an isocyanate group at a terminal derived from 1,6-hexamethylene diisocyanate (hereinafter abbreviated as HDI) is used. . Specific examples thereof include Duranate (registered trademark) TPA-100, TKA-100, TSA-100, TSS-100, TSE-100, TLA-100; Sumitomo Bayer Urethane manufactured by Asahi Kasei Kogyo Co., Ltd. Desmodur (registered trademark) N3390 manufactured by Co., Ltd .; Coronate (registered trademark) EH manufactured by Nippon Polyurethane Co., Ltd., Takenate D170N manufactured by Takeda Pharmaceutical Co., Ltd .; Barnock manufactured by Dainippon Ink and Chemicals, Inc. (DIC Co., Ltd.) (Registered trademark) DN980 and the like.

  Examples of the alicyclic polyisocyanate compound include isophorone diisocyanate, hydrogenated xylylene diisocyanate, 4,4′-dicyclohexylmethane diisocyanate (hydrogenated product of 4,4′-diphenylmethane diisocyanate, HMDI), 1,4-cyclohexanediisocyanate. , Methylcyclohexylene diisocyanate, 1,3-bis (isocyanatomethyl) cyclohexane and the like.

  As the hydrogenated product of 4,4'-diphenylmethane diisocyanate used in the present invention, polyisocyanate obtained by hydrogenating 4,4'-diphenylmethane diisocyanate (hereinafter, abbreviated as MDI) is used. As specific examples of these, there is WANGATE (registered trademark) HMDI manufactured by Wanhua Chemical Japan.

  Examples of the aromatic polyisocyanate compound include tolylene diisocyanate, 2,2′-diphenylmethane diisocyanate, 2,4′-diphenylmethane diisocyanate, 4,4′-diphenylmethane diisocyanate (MDI), 4,4′-dibenzyl diisocyanate, 1,5-naphthylene diisocyanate, xylylene diisocyanate, 1,3-phenylene diisocyanate, 1,4-phenylene diisocyanate and the like can be mentioned, preferably 2'-diphenylmethane diisocyanate, 2,4'-diphenylmethane diisocyanate, and 4,4. It is'-diphenylmethane diisocyanate (MDI).

  Examples of the araliphatic polyisocyanate compound include dialkyldiphenylmethane diisocyanate, tetraalkyldiphenylmethane diisocyanate, α, α, α, α-tetramethylxylylene diisocyanate, and the like.

  As the 4,4'-diphenylmethane diisocyanate (MDI) used in the present invention, a polyisocyanate having a carbodiimide group derived from 4,4'-diphenylmethane diisocyanate (carbodiimide-modified MDI) is used. Specific examples thereof include Millionate (registered trademark) MTL manufactured by Tosoh Corporation.

  The viscosity of the (A) polyisocyanate compound varies greatly depending on the type of polyisocyanate compound and the presence or absence of modification, but is not particularly limited. For example, in the case of an aromatic polyisocyanate compound and its modified products and polynuclear compounds (preferably carbodiimide compounds and polynuclear compounds of aromatic polyisocyanate compounds), the viscosity thereof is, for example, 5 to 200 mPa · s, preferably 10 at 25 ° C. ˜150 mPa · s, more preferably 15 to 100 mPa · s, still more preferably 20 to 80 mPa · s. As another example, in the case of an aliphatic polyisocyanate compound and its modified products and polynuclear bodies (preferably isocyanurate compounds of the aliphatic polyisocyanate compound), the viscosity thereof is, for example, 100 to 3000 mPa · s at 25 ° C., preferably It is 500 to 2500 mPa · s, more preferably 1000 to 2000 mPa · s, and further preferably 1200 to 1700 mPa · s.

  The NCO content of the (A) polyisocyanate compound is not particularly limited, but is, for example, 15 to 45%, more preferably 20 to 40%, and further preferably 20 to 35%.

  Among these, preferred commercially available products of the (A) polyisocyanate compound include, for example, Millionate (registered trademark) MTL (manufactured by Tosoh Corporation), Duranate (registered trademark) TPA-100 (manufactured by Asahi Kasei Chemicals Corporation), and luplanate (registered Trademark) M5S (manufactured by BASF INOAC Polyurethane Company), WANATE (registered trademark) HMDI (hydrogenated MDI, manufactured by Wanka Chemical Japan Co., Ltd.) and the like.

  The polyisocyanate compound (A) may be used alone or in any combination of two or more.

  The content of the (A) polyisocyanate compound is not particularly limited as long as it is an amount that can be adopted in the polyurethane resin composition (particularly, the polyurethane resin composition for encapsulating electric and electronic parts). The content is, for example, 1 to 75 parts by mass, preferably 5 to 65 parts by mass, and more preferably 8 to 40 parts by mass with respect to 100 parts by mass of the (B) polyol compound.

  The amount of the (A) polyisocyanate compound and the following (B) polyol compound is such that the NCO / OH ratio (INDEX), which is the ratio of the number of moles of isocyanate groups of the polyisocyanate compound to the number of moles of hydroxyl groups in the total of the polyol compounds, is 0. The range is 0.5 to 1.5, preferably 0.7 to 1.3, and more preferably 0.8 to 1.1.

  When the (A) polyisocyanate compound contains an isocyanurate body of a polyisocyanate compound (more preferably an isocyanurate body of an aliphatic polyisocyanate compound), the content is more improved in heat resistance and hydrolysis resistance. From the standpoint that it can be carried out, it is usually 0.01 to 30% by mass, preferably 0.1 to 25% by mass, and more preferably 1 to 100% by mass of the whole (A) polyisocyanate compound. -20 mass%, and more preferably 1.2-10.

  The (A) polyisocyanate compound is added to the (A1) polyisocyanate compound isocyanurate body (more preferably an isocyanurate body of an aliphatic polyisocyanate compound), and further (A2) a polynuclear body of the polyisocyanate compound (preferably, Aromatic polyisocyanate compound polynuclear body), or (A2) polyisocyanate compound polynuclear body (preferably aromatic polyisocyanate compound polynuclear body) and (A3) polyisocyanate compound carbodiimide body (preferably Is a carbodiimide compound of an aromatic polyisocyanate compound), the content of (A2) and / or (A3) is more than (A1) polyisocyanate compound from the viewpoint that electrical characteristics can be further improved. 100% by mass For example 1 to 1000 wt%, preferably from 5 to 800% by weight, more preferably 8-700 wt%, more preferably 65 to 500 wt%.

1-2. (B) Polyol Compound The (B) polyol compound used in the present invention is a (B1) polyfarnesene polyol compound (hereinafter sometimes referred to as “(B1) polyfarnesene polyol”), and (B2) polybutadiene. A system polyol compound (hereinafter sometimes referred to as “(B2) polybutadiene polyol”) and / or a (B3) castor oil system polyol compound (hereinafter sometimes referred to as “(B3) castor oil system polyol”). I'm out.

  As used herein, a "polymer" is a polymeric compound prepared by polymerizing monomers that may be the same or different. The generic term "polymer" includes the terms "homopolymer", "copolymer", "terpolymer" as well as "copolymer".

  "Copolymer" means a polymer prepared by the polymerization of at least two different monomers. The generic term "copolymer" refers to the term "copolymer" (generally means a polymer prepared from two different monomers) as well as the term "terpolymer" (generally from three different monomers). Means prepared polymers). Also included are polymers made by polymerizing four or more monomers.

(B1) Polyfarnesene Polyol Compound A polyfarnesene polyol compound means a polybutadiene polyol derived (produced) from farnesene.

  Farnesene is one of the sesquiterpene hydrocarbons, and is attracting attention not only as petroleum products but also as a biomaterial obtained from plants.

For this farnesene,
Formula (1a) below:
Α-farnesene represented by
Formula (1b) below:
β-farnesene and the like can be mentioned. Note that α-farnesene and β-farnesene may be used in combination.

  The polyfarnesene polyol used in the present invention includes not only a homopolymer but also a polyfarnesene polyol copolymer obtained from farnesene and another monomer. The polyfarnesene polyol is not particularly limited, and examples thereof include a polyfarnesene polyol copolymer derived from farnesene and at least one vinyl monomer.

  The content of the structural unit (X) derived from farnesene in the polyfarnesene polyol copolymer is 1 to 100% by mass. The content of the structural unit (X) derived from farnesene is preferably 1% by mass or more, more preferably 10 to 100% by mass, and more preferably 30 to 100% by mass from the viewpoint of flexibility and moldability. More preferably, 50 to 100 mass% is even more preferable, and 70 to 100 mass% is particularly preferable. When farnesene is bio-derived, the amount of conjugated dienes other than farnesene such as petroleum-derived butadiene and isoprene used can be suppressed, and petroleum dependence can be reduced.

The polyfarnesene polyol is not particularly limited, and for example, the general formula (2):
(In the formula, X is a structural unit derived from farnesene;
Y is a structural unit derived from a vinyl monomer;
m is an integer from 1 to 100,000;
n shows the integer of 0-100,000. And a compound having a hydroxyl group at the terminal. The polyfarnesene polyol includes primary alcohols, secondary alcohols and tertiary alcohols, preferably primary alcohols.

The X of the polyfarnesene is not particularly limited, and examples thereof include structural units represented by the following formulas (3) to (10) (wherein, two wavy lines mean parentheses [] in the above formula (2) X. And its stereoisomers.
(In the formula, R ¹ is, for example,
Formula (11):
A group represented by: (in the formula: the wavy line represents a binding site);
Formula (12):
A group represented by: (in the formula: the wavy line represents a binding site);
Formula (13):
A group represented by: (in the formula: the wavy line represents a binding site);
Formula (14):
The group represented by (in the formula: the wavy line represents a binding site) and the like.

  At least some of the double bonds in formulas (3)-(5) and (7)-(14), and in one or more of these stereoisomers, may be hydrogenated.

Y of the polyfarnesene disclosed in the present specification is a structural unit represented by the formula (15) (in the formula, two wavy lines mean parentheses [] in the above formula (2) Y) or stereoisomerism thereof. Having a body:
(In the formula, each of R ² , R ³ , R ⁴ , and R ⁵ is independently a hydrogen atom, a halogen atom, an alkyl group, a cycloalkyl group, an aryl group, an alkenyl group, an alkynyl group, an alkoxy group, or aryloxy. Group, carboxy group, alkoxycarbonyl group, optionally substituted amino group, acyloxy group, or nitrile).

  In the present specification, examples of the “halogen atom” include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom.

In the present specification, the “alkyl group” is not particularly limited, and examples thereof include C such as methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group and tert-butyl group. _{1 to 4} straight chain or branched chain alkyl groups can be mentioned. In the present specification, "n-" means normal, "sec-" means secondary, and "t-" means tertiary.

In the present specification, the “cycloalkyl group” is not particularly limited, and examples thereof include a C _3-8 linear or branched alkyl group such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl and the like. .

In the present specification, the “aryl group” is not particularly limited, and examples thereof include C _6-14 aryl groups such as phenyl, naphthyl group and anthryl group. This aryl group may have a substituent. Examples of the substituent include a halogen atom and an alkyl group.

In the present specification, the "alkenyl group" is not particularly limited and includes, for example, a C _2-10 straight chain such as vinyl group, allyl group, propenyl group, 3-acryloxypropyl group, 3-methacryloxypropyl group and the like. A branched or branched alkenyl group

In the present specification, the "alkynyl group" is not particularly limited, and examples thereof include C such as ethynyl group, 1-propynyl group, 2-propynyl group, 1-butynyl group, 3-butynyl group, pentynyl group and hexynyl group. _2-10 linear or branched alkynyl groups can be mentioned.

In the present specification, the "alkoxy group" is not particularly limited and includes, for example, methoxy group, ethoxy group, n-propoxy group, isopropoxy group, n-butoxy group, isobutoxy group, sec-butoxy group, tert-butoxy group. _Examples include C _1-4 linear or branched alkoxy groups such as groups.

In the present specification, the “aryloxy group” is not particularly limited, and examples thereof include a C _6-14 aryloxy group such as a phenyloxy (phenoxy) group, a naphthyloxy group and an _anthryloxy group. . This aryl group may have a substituent.

In the present specification, the “alkoxycarbonyl group” is not particularly limited, and examples thereof include C _1-4 alkoxy such as methoxycarbonyl group (CH ₃ OOC group) and ethoxycarbonyl group (CH ₃ CH ₂ OOC group). Carbonyl and the like can be mentioned. This alkoxy group may have a substituent.

In the present specification, the “amino group which may have a substituent (s)” is not particularly limited, and examples thereof include an unsubstituted amino group (NH ₂ ), a monoalkylamino group and a dialkylamino group. .

In the present specification, the “monoalkylamino group” is not particularly limited, and examples thereof include mono C _1-4 alkylamino groups such as methylamino group, ethylamino group, propylamino group and isopropylamino group.

In the present specification, the “dialkylamino group” is not particularly limited, and examples thereof include diC _1-4 alkylamino groups such as dimethylamino group, diethylamino group, ethylmethylamino group, dipropylamino group, diisopropylamino group and the like. Is mentioned.

  In the present specification, the “acyloxy group” is not particularly limited, and examples thereof include a formyloxy group, an acetyloxy group, a pivaloyloxy group and a stearoyloxy group.

  In the present specification, the “substituent” or “substitution” is not particularly limited, and examples thereof include a halogen atom, an alkyl group, an alkoxy group, a hydroxyl group, a nitro group, a cyano group and an alkoxycarbonyl group. When the compound has the substituent, the number of the substituent is not particularly limited and is usually 1 to 10, preferably 1 to 5, and more preferably 1 to 4.

  The m of the polyfarnesene polyol is usually 1 to 100,000, preferably 1 to 1,000, more preferably 1 to 100, particularly preferably 1 to 50.

  The n of the polyfarnesene polyol is usually 0 to 100,000, preferably 0 to 1,000, more preferably 0 to 100, particularly preferably 0 to 50.

  The sum of m and n of the polyfarnesene polyol is not particularly limited and is usually 1 to 200,000, preferably 1 to 2,000, more preferably 1 to 200, and particularly preferably 1 to 100.

  Examples of commercially available products of polyfarnesene polyol (B1) include polyfarnesene polyol [“Krasol (registered trademark) F3000” manufactured by CRAY VALLEY).

The number average molecular weight (Mn) of (B1) polyfarnesene polyol is usually in the range of 100 to 5,000, preferably in the range of 1,000 to 4,000, and more preferably in the range of 1,500 to 3,500.
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  The weight average molecular weight (Mw) of (B1) polyfarnesene polyol is usually in the range of 100 to 8000, preferably in the range of 1000 to 5000, and more preferably in the range of 1500 to 4000.

  The molecular weight distribution (Mw / Mn) of the (B1) polyfarnesene polyol is usually in the range of 0.1 to 10, preferably 0.5 to 2.0, and more preferably 1.0 to. The range is 1.5.

  The viscosity of the (B1) polyfarnesene polyol (25 ° C.) is usually in the range of 1 mPa · s to 100 Pa · s, preferably 100 to 5000 mPa · s, and more preferably 1000 to 3000 mPa · s. Is the range.

The glass transition temperature of (B1) polyfarnesene polyol (30 ° C.) is usually in the range of −100 to 0 ° C., preferably −80 to −30 ° C., and more preferably −70 to −−. It is in the range of 40 ° C.
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The above-mentioned (B1) polyfarnesene polyols can be used alone or in combination of two or more.
(B2) Polybutadiene polyol (B2) Polybutadiene polyol means a polybutadiene polyol other than the above-mentioned (B1) polyfarnesene polyol compound.

  The (B2) polybutadiene polyol is not particularly limited, and for example, (b2-1) polybutadiene polyol having a hydroxyl value of 60 mgKOH / g or less (hereinafter, may be referred to as “(b2-1) polybutadiene polyol”), ( b2-2) Polybutadiene polyol having a hydroxyl value of more than 60 mgKOH / g (hereinafter may be referred to as “(b2-2) polybutadiene polyol”) and the like.

  Examples of commercially available products of the polybutadiene polyol (B2) include polybutadiene polyol [“NISSO-PBG series” manufactured by Nippon Soda Co., Ltd. (G-1000, G-2000, G-3000, etc.); (Registered trademark) series "(R-45M, R-15HT, R-45HT, CS-15, CN-15, etc.)] and the like.

  The hydroxyl value of the (b2-1) polybutadiene polyol is preferably 1 to 58 mgKOH / g, more preferably 5 to 55 mgKOH / g, and particularly preferably 10 to 50 mgKOH / g.

  The hydroxyl group content of the (b2-1) polybutadiene polyol is not particularly limited and is usually 0.001 to 3 mol / kg, preferably 0.01 to 2 mol / kg, and more preferably 0.1 to 1 mol. It is 0.2 mol / kg.

The number average molecular weight (Mn) of the (b2-1) polybutadiene polyol is usually in the range of 100 to 5,000, preferably in the range of 1,000 to 4,000, and more preferably in the range of 1,500 to 3,500.
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The viscosity of the (b2-1) polybutadiene polyol (30 ° C.) is usually in the range of 0.01 to 100 Pa · s, preferably 0.1 to 100 Pa · s, and more preferably 1 to 10 Pa · s. The range is s.
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The iodine value of the polybutadiene polyol (b2-1) is usually in the range of 1 to 1000 g / 100 g, preferably 10 to 600 g / 100 g, and more preferably 100 to 500 g / 100 g.
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  The hydroxyl value of the polybutadiene polyol (b2-2) is preferably 61 to 300 mgKOH / g, more preferably 70 to 200 mgKOH / g, and particularly preferably 80 to 150 mgKOH / g.

  The hydroxyl group content of the (b2-2) polybutadiene polyol is not particularly limited and is usually 0.001 to 3 mol / kg, preferably 0.01 to 2 mol / kg, and more preferably 0.1 to 1 mol. It is 0.2 mol / kg.

The number average molecular weight (Mn) of the (b2-2) polybutadiene polyol is usually in the range of 100 to 5,000, preferably in the range of 1,000 to 4,000, and more preferably in the range of 1,500 to 3,500.
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  The viscosity of the (b2-2) polybutadiene polyol (30 ° C.) is usually in the range of 0.01 to 100 Pa · s, preferably 0.1 to 100 Pa · s, and more preferably 1 to 10 Pa · s. The range is s.

  The iodine value of the (b2-2) polybutadiene polyol is usually in the range of 1 to 1000 g / 100 g, preferably in the range of 10 to 600 g / 100 g, and more preferably in the range of 100 to 500 g / 100 g.

  The above (B2) polybutadiene polyols can be used alone or in combination of two or more.

(B3) Castor oil-based polyol The castor oil-based polyol is not particularly limited, and examples thereof include castor oil and castor oil derivatives.

  Examples of the castor oil derivative include castor oil fatty acid; castor oil or hydrogenated castor oil hydrogenated to castor oil fatty acid; transesterification product of castor oil and other oils and fats; reaction product of castor oil and polyhydric alcohol; Esterification reaction products of castor oil fatty acid and polyhydric alcohol; compounds obtained by addition-polymerizing alkylene oxide to these are mentioned. Of the above castor oil-based polyols, castor oil is preferably used.

  Examples of the hydrogenated castor oil include those disclosed in JP-A-2-298574. The hydrogenated castor oil can be obtained by hydrogenating the above-mentioned castor oil-based polyol.

  Examples of commercially available castor oil-based polyols include castor oil polyol [“H-35” manufactured by Ito Oil Co., Ltd.] and [KSK polyol manufactured by Toyokuni Oil Co., Ltd.].

  The number average molecular weight (Mn) of the castor oil-based polyol is usually in the range of 100 to 4,000, preferably 300 to 2,500.

  The castor oil-based polyol preferably has an average hydroxyl value determined according to JIS K1557-1 of 20 to 250 mgKOH / g, more preferably 50 to 120 mgKOH / g.

  In the present specification, the number average molecular weight (Mn) can be measured by gel permeation chromatography (GPC) method (polystyrene conversion). The number average molecular weight according to the GPC method is specifically Shodex GPC System21 manufactured by Showa Denko KK as a measuring device, and Shodex LF-804 / KF-803 / KF-804 manufactured by Showa Denko KK as a column. It can be calculated by using NMP as a mobile phase, measuring at a column temperature of 40 ° C., and using a calibration curve of standard polystyrene.

  The (B) polyol compound used in the present invention further includes (B1) a polyfarnesene polyol compound, (B2) a polybutadiene-based polyol compound, and (B3) a polyol compound (B4) other than castor oil-based polyol (hereinafter, referred to as " (B4) Polyol "may be contained).

  Examples of the (B4) polyol compound include dimer acid polyols; polydiene polyols (polyisoprene polyols and the like); polyether polyols; polyester polyols; polycarbonate polyols; polycaprolactone polyols; hydrides of these (for example, polydiene polyol Hydride etc.) and the like.

  The dimer acid polyol is not particularly limited, and known dimer acid polyols can be used.

  The polydiene polyol is not particularly limited, and examples thereof include polyisoprene polyol [“Poly ip” manufactured by Idemitsu Kosan Co., Ltd.).

  The hydride of the polydiene polyol is not particularly limited, and examples thereof include hydrides of polybutadiene polyol [Nisso-PBGI series manufactured by Nippon Soda Co., Ltd. (GI-1000, GI-2000, GI-3000, etc.)], Examples include hydrides of polyisoprene polyol [“Epol” manufactured by Idemitsu Kosan Co., Ltd.] and the like.

  The polyether polyol is not particularly limited, and examples thereof include water, low molecular weight polyols (propylene glycol, ethylene glycol, glycerin, trimethylolpropane, pentaerythritol, etc.), bisphenols (bisphenol A, etc.), dihydroxybenzene (catechol, resorcinol, etc.). , Hydroquinone, etc.) as an initiator, and polyether polyols obtained by addition-polymerizing alkylene oxides such as ethylene oxide, propylene oxide and butylene oxide. Specific examples include polyethylene glycol, polypropylene glycol, polytetramethylene glycol and the like.

  Examples of commercially available polyether polyols include, for example, polyether polyol [ADEKA Co., Ltd. "T-400"], [Mitsui Chemicals Actcoal "D-2000"], and Sanyo Chemical Co., Ltd. "SK-2000". ]] And the like.

  The polyester polyol is not particularly limited and can be obtained, for example, by an esterification reaction between a polyol component and an acid component.

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

  The acid component is not particularly limited, for example, succinic acid, methylsuccinic acid, adipic acid, pimelic acid, azelaic acid, sebacic acid, 1,12-dodecanedioic acid, 1,14-tetradecanedioic acid, dimer acid, 2-Methyl-1,4-cyclohexanedicarboxylic acid, 2-ethyl-1,4-cyclohexanedicarboxylic acid, terephthalic acid, isophthalic acid, phthalic acid, isophthalic acid, terephthalic acid, 1,4-naphthalenedicarboxylic acid, 4,4 Examples thereof include'-bipheerdicarboxylic acid and acid anhydrides thereof.

  The polycarbonate polyol is not particularly limited, and for example, a polycarbonate polyol obtained by polycondensation reaction of the above polyol component and phosgene; the above polyol component and dimethyl carbonate, diethyl carbonate, diprobyl carbonate, diisopropyl carbonate, dibutyl carbonate, ethylbutyl. Polycarbonate polyols obtained by transesterification condensation with carbonic acid diesters such as carbonic acid, ethylene carbonate, propylene carbonate, diphenyl carbonate, dibenzyl carbonate; copolymerized polycarbonate polyols obtained by using two or more of the above polyol components together; Polycarbonate polyol obtained by esterifying a polyol and a carboxyl group-containing compound; the above various polycarbonate polyols and hydroxyl Polycarbonate polyol obtained by etherification reaction of a containing compound; Polycarbonate polyol obtained by transesterification reaction of each of the above polycarbonate polyol and ester compound; Obtained by transesterification reaction of each of the above polycarbonate polyol and hydroxyl group-containing compound Polycarbonate polyols obtained; polyester-based polycarbonate polyols obtained by polycondensation reaction between the above-mentioned various polycarbonate polyols and dicarboxylic acid compounds; copolymerized polyether-based polycarbonate polyols obtained by copolymerizing the above-mentioned various polycarbonate polyols and alkylene oxides Can be mentioned.

  Examples of commercially available products of polycarbonate polyol include polycarbonate polyol [“T-5650E” manufactured by Asahi Kasei Co., Ltd.] and [UH-50 ”manufactured by Ube Industries, Ltd.].

  The polycaprolactone polyol is not particularly limited, and examples thereof include caprolactone-based polyester diols obtained by ring-opening polymerization of cyclic ester monomers such as ε-caprolactone and δ-valerolactone.

  The (B) polyol compound used in the present invention contains (B1) a polyfarnesene polyol compound, and (B2) a polybutadiene-based polyol compound and / or (B3) a castor oil-based polyol, and these (B1), Each of (B2) and (B3) can be used alone or in combination of two or more. Further, a polyol compound (B4) other than the above (B1), (B2) and (B3) can be blended, and when blended, the (B4) polyol can also be used alone or in combination of two or more. It is also possible to mix and use.

The content of the (B1) polyfarnesene polyol compound used in the present invention is not particularly limited, and is usually 0.01 to 90 mass% with respect to 100 mass% of the polyurethane resin composition, and preferably 1 ˜85 mass%, more preferably 5˜80 mass%.

1-3. (C) Inorganic Filler The polyurethane resin composition of the present invention may further contain (C) an inorganic filler, if necessary.

  The inorganic filler (C) used in the present invention is not particularly limited, and examples thereof include metal hydroxides, metal oxides, metal nitrides and zeolites.

  Examples of the metal hydroxide include aluminum hydroxide and magnesium hydroxide.

  Examples of the metal oxide include aluminum oxide (alumina), magnesium oxide, silicon oxide (silica and the like), titanium oxide and the like.

  Examples of the metal nitride include boron nitride, aluminum nitride, silicon nitride and the like.

  The zeolite is not particularly limited, and those used in known polyurethane resin compositions can be used.

  Among them, the zeolite is preferably a crystalline hydrous aluminosilicate of an alkali metal or an alkaline earth metal.

  The crystal form of zeolite is not particularly limited, and examples thereof include A type, X type, and LSX type. Of these, the preferred crystal form is A type.

  The alkali metal or alkaline earth metal in the zeolite is not particularly limited, and examples thereof include potassium, sodium, calcium and lithium. Of these, potassium is preferable.

  Preferred inorganic fillers are metal hydroxides and oxides, more preferably aluminum hydroxide and alumina, and particularly preferably aluminum hydroxide.

  The (C) inorganic filler may be used alone or in combination of two or more.

  When the inorganic filler (C) is blended, the content thereof is usually 50 to 85% by mass, preferably 52 to 75% by mass, and more preferably 100% by mass of the polyurethane resin composition. It is 54 to 70% by mass, and particularly preferably 55 to 69% by mass.

The shape of the inorganic filler (C) may be spherical or irregular.
1-4. (D) Plasticizer The polyurethane resin composition of the present invention may further contain (D) a plasticizer, if necessary.

  The (D) plasticizer used in the present invention is not particularly limited, and examples thereof include phthalate ester-based plasticizers such as dioctyl phthalate, diisononyl phthalate (diisononyl phthalate) and diundecyl phthalate; dioctyl adipate, diisononyl adipate, diisodecyl adipate. Castor oil ester plasticizers such as adipic acid ester-based plasticizers such as; methylacetylricinoleate, butylacetylricinoleate, acetylated ricinoleic acid triglyceride, acetylated polyricinolic acid triglyceride; Trimellitic acid esters such as melitate; pyromellitic acid ester plasticizers such as tetraoctylpyromellitate and tetraisononylpyromellitate. Among these, phthalic acid ester plasticizers and adipic acid ester plasticizers are preferable, and adipic acid ester plasticizers are more preferable.

  When blending the (D) plasticizer, the content thereof is usually 1 to 30% by mass, preferably 10 to 29% by mass, and more preferably 12% with respect to 100% by mass of the polyurethane resin composition. ˜28% by mass, particularly preferably 15 to 26% by mass.

  The above (D) plasticizers can be used alone or in a mixture of two or more.

1-5. (E) Crosslinking Agent The polyurethane resin composition of the present invention may further contain (E) a crosslinking agent, if necessary.
The (E) cross-linking agent (also known as a chain extender) is not particularly limited, and examples thereof include N, N-bis (2-hydroxypropyl) aniline, hydroquinone-bis (β-hydroxyethyl) ether, resorcinol-bis ( (E1) aromatic alcohol-based crosslinking agent such as β-hydroxyethyl) ether;
(E2) Aliphatic alcohol-based crosslinking agents such as ethylene glycol, 1,4-butanediol, octanediol, trimethylolpropane, and triisopropanolamine;
Phenylenediamine, tolylenediamine, diphenyldiamine, 4,4'-diaminodiphenylmethane, 3,3'-dichloro-4,4'-diaminodiphenylmethane, 1,2-bis (2-aminophenylthio) ethane, trimethylene glycol -(E3) aromatic amine crosslinking agent such as p-aminobenzoate;
Examples thereof include (E4) aliphatic amine-based crosslinking agents such as ethylenediamine, propylenediamine, hexamethylenediamine, and diethylenetriamine. Among these, (E1) aromatic alcohol-based crosslinking agent and (E2) aliphatic alcohol-based crosslinking agent are preferable, and (E1) aromatic alcohol-based crosslinking agent is more preferable.

  The number average molecular weight of the above (E) crosslinking agent is usually 1000 or less, preferably 500 or less as the number average molecular weight, and more preferably 400 or less as the number average molecular weight.

  When blending the crosslinking agent (E), its content is not particularly limited and is, for example, usually 0.01 to 30% by mass, preferably 0.1 to 100% by mass of the polyurethane resin composition. ˜20% by mass, more preferably 0.3 to 10% by mass, and particularly preferably 0.5 to 5% by mass.

  The (E) cross-linking agent may be used alone or in a mixture of two or more kinds.

1-6. Defoaming agent (F)
The polyurethane resin composition of the present invention may further contain an antifoaming agent (F), if necessary.

  The defoaming agent used in the present invention is not particularly limited, and examples thereof include silicones (oil type, compound type, self-emulsifying type, emulsion type, etc.), alcohols and the like.

  A preferred silicone antifoaming agent is a modified silicone antifoaming agent (particularly, a polysiloxane modified with a lipophilic group and a hydrophilic group).

  The defoaming agents (F) can be used alone or in a mixture of two or more.

  When compounding the defoaming agent (F), its content is not particularly limited, and is preferably 0.001 to 10% by mass, relative to 100% by mass of the polyurethane resin composition, and 0.005 to 5% by mass. % Is more preferable.

1-7. (G) Polymerization catalyst The polyurethane resin composition of the present invention may further contain (G) a polymerization catalyst, if necessary.

  As the polymerization catalyst (G), known polymerization catalysts can be used, and examples thereof include metal catalysts such as organic tin catalysts, organic lead catalysts and organic bismuth catalysts; amine catalysts.

  Examples of the organic tin catalyst include dioctyl tin dilaurate, dibutyl tin diacetate, dibutyl tin dilaurate, dioctyl tin diacetate and the like.

  Examples of the organic lead catalyst include lead octylate, lead octenoate, and lead naphthenate.

  Examples of the organic bismuth catalyst include bismuth octylate and bismuth neodecanoate.

  Examples of the amine catalyst include diethylenetriamine, triethylamine, N, N-dimethylcyclohexylamine, N, N, N ′, N ′ tetramethylethylenediamine, N, N, N ′, N ″, N ″ -pentamethyldiethylenetriamine, triethylamine. Examples thereof include methylenediamine, dimethylaminoethanol, bis (2-dimethylaminoethyl) ether and the like. Further, as the catalyst, an organometallic compound, a metal complex compound or the like may be used.

  When compounding the (G) polymerization catalyst, its content is not particularly limited, and is, for example, usually 0.00001 to 10% by mass, preferably 0.0001 to 100% by mass of the polyurethane resin composition. To 5% by mass, and more preferably 0.001 to 1% by mass.

  The (G) polymerization catalyst can be used alone or in a mixture of two or more kinds.

1-8. Other components The polyurethane resin composition of the present invention further contains, if necessary, an antioxidant, a tackifier, a curing accelerator, a colorant, a chain extender, a crosslinker, a filler, a pigment, a filler, a flame retardant, It may contain various additives such as a urethanization catalyst, an ultraviolet absorber, a moisture absorbent, an antifungal agent and a silane coupling agent.

  The contents of these components may be appropriately determined according to the purpose of use so as not to impair the desired properties of the polyurethane resin composition from the usual addition amounts and the range of identification.

  No foaming agent is added to the polyurethane resin composition of the present invention. That is, the polyurethane resin composition of the present invention is intended for heat dissipation and the like by the inorganic filler, whereas the foamed urethane foam containing the foaming agent is intended for heat insulation and the like, so the two have different purposes. .

2. Method for Producing Polyurethane Resin Composition The method for producing the polyurethane resin composition of the present invention is not particularly limited, and it can be produced according to a known method used as a method for producing a polyurethane resin composition.

  As such a manufacturing method, for example, a step (step 1) of preparing a composition (first component) containing the (A) polyisocyanate compound, and a composition (second component) containing the (B) polyol compound are prepared. Examples of the method include a step of performing (step 2) and a step of mixing the second component and the first component to obtain a polyurethane resin composition (step 3). When the first component or the second component is a mixture of two or more compounds, each compound can be added individually or all at once.

  If the first component (I agent) contains the (A) polyisocyanate compound and the second component (II agent) contains the (B) polyol compound, the other component is the second component or the second component. It may be contained in either one of the components. Also,

For example, the first component contains (A) polyisocyanate compound and (D) plasticizer, the second component contains (B) polyol compound and (C) inorganic filler; the first component (A) A structure containing a polyisocyanate compound and a second component containing (B) a polyol compound, (C) an inorganic filler and (D) a plasticizer;
A constitution in which the first component contains (A) polyisocyanate compound and (D) plasticizer, and the second component contains (B) polyol compound, (C) inorganic filler and (D) plasticizer can be mentioned. .

Further, the first component contains (A) polyisocyanate compound and (C) inorganic filler, and the second component contains (B) polyol compound;
The first component contains (A) polyisocyanate compound and (D) plasticizer, and the second component contains (B) polyol compound, (C) inorganic filler, (D) plasticizer and (E) crosslinking agent. Configuration to do;
The first component contains (A) polyisocyanate compound and (D) plasticizer, and the second component (B) polyol compound, (C) inorganic filler, (D) plasticizer, (E) crosslinking agent and ( F) A composition containing an antifoaming agent;
The first component contains (A) polyisocyanate compound and (D) plasticizer, and the second component (B) polyol compound, (C) inorganic filler, (D) plasticizer, (E) crosslinking agent, ( The composition may contain F) an antifoaming agent and (G) a polymerization catalyst.

When producing a polyurethane resin composition, the first component (I agent) is usually 1 to 1000 parts by mass, preferably 3 to 100 parts by mass, relative to 100 parts by mass of the second component (II agent). It is preferably 5 to 25 parts by mass.
The reason for blending the other component with the first component is to lower the viscosity of the polyisocyanate compound and to match the ratio (blending ratio) between the first component and the second component. Therefore, the first component can be used without blending other components.

  In the polyurethane resin composition, the polyisocyanate compound (A) and the polyol compound (B) may partly or wholly react to form a polyurethane resin. That is, the polyurethane resin composition may be in a liquid state before curing or may be cured. As a method for curing the polyurethane resin composition, by mixing the first component and the second component, the (A) polyisocyanate compound and the (B) polyol compound react with each other to form a polyurethane resin. A method of curing the resin composition with time is mentioned, but it may be cured by heating. In this case, the heating temperature is preferably about 40 to 120 ° C., and the heating time is preferably about 0.5 to 24 hours.

3. Applications The present invention is also a sealing material made of the above polyurethane resin composition. The encapsulant made of the polyurethane resin composition has excellent heat dissipation, hydrolysis resistance, and flame retardancy, and the deterioration of flame retardance is suppressed even when used in a high temperature environment. Therefore, it can be suitably used for electric and electronic parts that generate heat.

  Examples of such electric / electronic components include transformers such as transformer coils, choke coils, reactor coils, device control boards, and various sensors. Such an electric / electronic component is also one aspect of the present invention. The electric / electronic component of the present invention can be used in, for example, an electric washing machine, a toilet seat, a water heater, a water purifier, a bath, a dishwasher, an electric tool, an automobile, a motorcycle, and the like.

  Hereinafter, the polyurethane resin composition of the present invention will be specifically described with reference to Examples and Comparative Examples. However, the embodiments are merely examples, and the present invention is not limited to the embodiments.

  The raw materials used in Examples and Comparative Examples are shown below.

<(A) Polyisocyanate compound>
а1: MTL
Product name: Millionate (registered trademark) MTL (carbodiimide modified MDI), manufactured by Tosoh Corporation

<(B) Polyol compound>
b1: Polyfarnesene polyol Product name: Krasol F3000 CRAY VALLEY b2-1: R-45HT
Product name: Poly bd (registered trademark) R-45 HT, manufactured by Idemitsu Petrochemical Co., Ltd., number average molecular weight 2800, hydroxyl value 46.6 mg KOH / g (JIS K 1557), hydroxyl content 0.83 mol / kg (JIS K 1557) , Iodine value 398g / 100g (JIS K 0070), viscosity 5Pa ・ S / 30 ℃ (JIS K 2283)
b2-2: R-15HT
Product name: Poly bd (registered trademark) R-15 HT, manufactured by Idemitsu Petrochemical Co., Ltd., number average molecular weight 1200, hydroxyl value 102.7 mg KOH / g (JIS K 1557), hydroxyl content 1.83 mol / kg (JIS K 1557) , Iodine value 420g / 100g (JIS K 0070), viscosity 1.5Pa ・ S / 30 ℃ (JIS K 2283)
b3: H-35 (castor oil)
Product name: H-35, Ito Oil Co., Ltd. b4-1 (comparative polyol): Polycarbonate diol Product name: T-5650E, Asahi Kasei Co., Ltd. b4-2 (comparative polyol): Polyether polyol Product name: T-400 Stock Company ADEKA

<(F) Defoaming agent>
f1: SC-5570
Product name: SC-5570 (silicone defoamer), manufactured by Toray Dow Corning

Preparation of Polyurethane Resin Composition < Reference Examples 1-6, Example 7 and Comparative Examples 1-3>
The composition shown in Table 1 and 0.01% by weight of SC-5570 (silicone defoaming agent) as a defoaming agent were added to each component, and various polyurethane resin compositions were prepared by the following procedure.

Specifically, the (B) polyol compound and the (F) antifoaming agent shown in Table 1 were mixed for 1 minute at 2000 rpm using a rotation / revolution mixer (Awatori Kentaro, manufactured by Shinky Co., Ltd.).
The polyisocyanate compound (A) shown in Table 1 was added to the above-mentioned mixed components, and they were mixed for 1 minute at 2000 rpm using a rotation / revolution mixer (Awatori Kentaro, manufactured by Shinky Co., Ltd.). The obtained mixture was degassed to obtain each polyurethane resin composition of Reference Examples 1 to 6, Example 7 and Comparative Examples 1 to 3.

<Preparation of test piece>
The prepared polyurethane resin composition was injected into a 100 × 100 × 3 mm molding die, a 100 × 100 × 1 mm molding die, or a molding die having an inner diameter of 30 mm and a height of 10 mm. Then, the polyurethane resin composition was heated at 60 ° C. for 16 hours and then left standing at room temperature for 1 day to cure.

  With respect to the obtained test piece A (100 × 100 × 3 mm), test piece B (100 × 100 × 1 mm), and test piece C (inner diameter 30 mm and height 10 mm), hardness, compatibility (viscosity), The volume resistance value, elongation rate, tensile strength, dielectric breakdown, elastic modulus (DMS method: 10 Hz), or humidity resistance was measured by the following test methods. The results are shown in Table 1.

<Hardness>
The hardness (type A) when the temperature of the test piece C (inner diameter 30 mm, height 10 mm) is 23 ° C., JIS K 6253, hardness (type C), according to JIS K 7312, hardness meter (manufactured by Kobunshi Keiki Co., Ltd.). , Asker rubber hardness tester A type).

<Compatibility (overview)>
The mixed liquid of the “polyol compound and the defoaming agent” was heated in a dryer at 60 ° C. for 1 week, cooled to room temperature (23 ° C.), and then the appearance was confirmed.

◎: Transparent without liquid separation ◯: No liquid separation, slightly cloudy Δ: No liquid separation, cloudy ×: Separation

<Tensile strength>
The tensile strength of the test piece A was evaluated according to JIS K6301 (or JIS K6251).

<Elongation rate (flexibility)>
The elongation (flexibility) of the test piece A was evaluated according to JIS K 6301 (or JIS K 6251) based on the following formula.

Formula: Elongation rate = {[(mark distance between breaking lines)-(mark distance)] / (mark distance)} x 100
A: Elongation rate is 100% or more C: Elongation rate is less than 100%

<Elastic modulus (10 Hz)>
The elastic modulus (10 Hz) of the test piece A was measured using a dynamic viscoelasticity measuring device: DMS (manufactured by SII Nano Technology: DMS6100). The elastic modulus was evaluated according to the following evaluation criteria.

<Volume resistance value>
The volume resistivity of the test piece A was measured using a resistance meter (manufactured by HIOKI, DSM-8104). Based on the measurement results, the insulation was evaluated according to the following evaluation criteria. Table 1 shows measured values (Ω · cm) of volume resistivity and evaluation results.
Volume resistivity is 1 × 10 ¹² Ω · cm or more.

<Dielectric breakdown>
The dielectric breakdown strength of the test piece B was measured using a dielectric breakdown strength measuring instrument.
Based on the measurement results, the dielectric breakdown strength was evaluated according to the following evaluation procedure.
◎: 22 kV / mm or more ○: 20 kV / mm or more

<Moisture resistance PCT (121 ℃ / 100% RH)>
The moisture resistance of the test piece C was subjected to a pressure cooker test (PCT test) under the conditions of 121 ° C./100% RH and 2 atm, and the time for the test piece C to dissolve was measured.
Based on the measurement results, the moisture resistance was evaluated according to the following evaluation procedure.
◎: 200h or more 〇: 100h or more

<Judgment result>
From the results of Example 7 , the polyurethane resin of the present invention can reduce the temperature dependence of the elastic modulus (−20 ° C. to −40 ° C.), exhibits excellent elongation (flexibility), and changes in hardness due to thermal deterioration. Could be suppressed.

  Further, it was found that the polyurethane resin composition of the present invention satisfied all items of excellent hardness, compatibility, volume resistance value, elongation rate, tensile strength, dielectric breakdown, elastic modulus, and moisture resistance.

  On the other hand, in Comparative Examples 1 to 3, the compositions were not able to satisfy all the items of hardness, compatibility, volume resistance value, elongation rate, tensile strength, dielectric breakdown, elastic modulus, and moisture resistance.

When the polyurethane resin composition of the present invention is used, the obtained polyurethane resin cured product satisfies all the items of heat resistance, moisture resistance, and heat cycle property, and therefore can be used in the fields of electric products, electronic parts, etc. It is possible.

Claims (13)

A polyurethane resin composition containing (A) a polyisocyanate compound and (B) a polyol compound,
The (B) polyol compound is
A polyurethane resin composition comprising (B1) a polyfarnesene polyol compound and (B3) castor oil-based polyol. The (B) polyol compound is
(B1) polyfarnesene polyol compound, and (B3) castor oil-based polyol; or (B1) polyfarnesene polyol compound, (B2) polybutadiene-based polyol compound, and (B3) castor oil-based polyol. Item 2. The polyurethane resin composition according to item 1. The blending ratio of the (B1) polyfarnesene polyol compound and the (B2) polybutadiene- based polyol compound and / or (B3) castor oil-based polyol is 10 to 90:90 to 10, and the blending ratio is 10 to 90:90 to 10. The polyurethane resin composition described in 1. The blending ratio of the (B1) polyfarnesene polyol compound and the (B2) polybutadiene- based polyol compound and / or (B3) castor oil-based polyol is 10 to 70:90 to 30. The polyurethane resin composition according to any one of 1. 5. The (B) polyol compound is (B1) polyfarnesene polyol compound, (B2) polybutadiene-based polyol compound, and (B3) castor oil-based polyol, according to any one of claims 1 to 4. Polyurethane resin composition. The number average molecular weight (Mn) of the (B1) polyfarnesene polyol compound is 100-5000, The polyurethane resin composition as described in any one of Claims 1-5. The polyurethane resin composition according to any one of claims 1 to 6, wherein the viscosity (25 ° C) of the (B1) polyfarnesene polyol compound is in the range of 1 to 100 Pa · s. The polyurethane resin composition according to any one of claims 1 to 7, wherein the glass transition temperature (30 ° C) of the (B1) polyfarnesene polyol compound is in the range of -100 to 0 ° C. Wherein (B2) polybutadiene polyol compound is less polybutadiene polyol hydroxyl value 60 mg KOH / g, the polyurethane resin composition according to any one of claims 2-8. Wherein (B2) polybutadiene polyol compound has a number average molecular weight (Mn) in the range of 100 to 5,000, the polyurethane resin composition according to any one of claims 2-9. The polyurethane resin composition according to any one of claims 1 to 10, which is used for encapsulating electric and electronic parts. An encapsulant comprising the polyurethane resin composition according to claim 1. An electric / electronic component resin-sealed using the sealing material according to claim 12.