JP5897184B1 - Polyurethane resin composition - Google Patents

Abstract

A polyurethane resin composition having excellent thermal conductivity and excellent workability and storage stability is provided. A polyurethane resin composition comprising a polyurethane resin (C) comprising a polyol compound (A) having two or more hydroxyl groups and a polyisocyanate compound (B), and an inorganic filler (D). An inorganic filler (D) comprising the following (D1) and (D2). (D1): The ratio (D90) / (D10) of the volume-based cumulative 90% particle diameter (D90) and the volume-based cumulative 10% particle diameter (D10) in the particle size distribution measured by the laser diffraction scattering method is 1. And an aluminum hydroxide particle having a volume-based cumulative 50% particle diameter (D50) of 0.1 to 3 μm; (D2): the particle size distribution obtained by the same measurement method as D1 is (D90) / Aluminum hydroxide particles having (D10) of 1 to 15 and a particle diameter of 5 to 15 μm. [Selection figure] None

Description

  The present invention relates to a polyurethane resin composition.

  In recent years, the density and integration of electric and electronic parts have been increased, and improvement of reliability is required for each part. In particular, electrical and electronic parts used in car engines, water heaters, and the like are required to have high reliability even in a high temperature and high humidity environment.

  These electric and electronic parts are sealed with a sealing material to impart moisture resistance, and a polyurethane resin is used as the sealing material. In recent years, electrical and electronic parts are easily affected by heat generation due to downsizing, and polyurethane resins used for the sealing materials as described above are required to have high thermal conductivity (heat dissipation).

  In order to impart thermal conductivity to the polyurethane resin used as the sealing material as described above, it is necessary to fill the polyurethane resin composition with a thermally conductive filler such as an inorganic substance in a high blending amount.

  As a polyurethane resin composition for preparing a polyurethane resin exhibiting thermal conductivity, for example, a polyurethane resin composition containing a hydroxyl group-containing compound, an isocyanate group-containing compound and an inorganic filler (D), the hydroxyl group-containing compound Contains a polybutadiene polyol (A), the isocyanate group-containing compound contains an isocyanurate-modified product (B) of a polyisocyanate compound and an allophanate-modified product (C) of a polyisocyanate compound, and the inorganic filler (D ) Is one or more selected from the group consisting of alumina, aluminum hydroxide, aluminum nitride, boron nitride, magnesium hydroxide and magnesium oxide, and the blending amount of the inorganic filler (D) is relative to the polyurethane resin composition Polyurethane of 50 to 95% by mass Fat compositions have been proposed (see Patent Document 1).

  However, the conventional polyurethane resin composition has been studied for thermal conductivity, but not for workability. The conventional polyurethane resin composition has not been studied in detail with respect to the particle size of the inorganic filler, and the viscosity increases because the amount of the inorganic filler is large, so that the polyurethane resin composition enters the gap between the electric and electronic parts. There is a problem that it is difficult.

  Furthermore, in the conventional polyurethane resin composition, there exists a problem that an inorganic filler aggregates and precipitates easily and is inferior in storage stability.

  Therefore, development of a polyurethane resin composition excellent in heat conductivity and excellent in workability and storage stability is demanded.

Japanese Patent No. 5550161

  An object of the present invention is to provide a polyurethane resin composition having excellent thermal conductivity and excellent workability and storage stability.

  As a result of intensive studies, the present inventor has obtained a polyurethane resin (C) comprising a polyol compound (A) having two or more hydroxyl groups and a polyisocyanate compound (B), and a polyurethane resin containing an inorganic filler (D). In the composition, the inorganic filler (D) is found to be able to achieve the above-mentioned object if the constitution contains (D1) and (D2) which are aluminum hydroxide particles having a specific particle diameter. It came to complete.

That is, this invention relates to the following polyurethane resin compositions, sealing materials, and electric / electronic parts.
1. A polyurethane resin composition containing a polyurethane resin (C) comprising a polyol compound (A) having two or more hydroxyl groups and a polyisocyanate compound (B), and an inorganic filler (D),
The said inorganic filler (D) contains the following (D1) and (D2), The polyurethane resin composition characterized by the above-mentioned;
(D1): Ratio (D ₉₀ ) / (D of the volume-based cumulative 90% particle diameter (D ₉₀ ) and the volume-based cumulative 10% particle diameter (D ₁₀ ) in the particle size distribution measured by the laser diffraction scattering method. ₁₀ ) is 1 to 5 and the volume-based cumulative 50% particle diameter (D ₅₀ ) is 0.1 to 3 μm aluminum hydroxide particles;
(D2): Ratio (D ₉₀ ) / (D) of volume-based cumulative 90% particle diameter (D ₉₀ ) and volume-based cumulative 10% particle diameter (D ₁₀ ) in the particle size distribution measured by the laser diffraction scattering method. ₁₀ ) is an aluminum hydroxide particle having 1 to 15 and a volume-based cumulative 50% particle diameter (D ₅₀ ) of 5 to 15 μm.
2. The (D2) _{is, (D 90) / (D} 10) is 5-10, and, _{(D 50)} is 5 to 15 [mu] m, the polyurethane resin composition according to claim 1.
3. The polyol compound (A) having two or more hydroxyl groups contains a castor oil-based polyol (A1) and a polybutadiene polyol (A2), and the content of the (A1) with respect to (A) 100% by mass is as follows: Item 3. The polyurethane resin composition according to Item 1 or 2, which is 50% by mass or less.
4). Item 4. A sealing material comprising the polyurethane resin composition according to any one of Items 1 to 3.
5. Item 5. An electrical and electronic component sealed with a resin using the sealing material according to Item 4.

  The polyurethane resin composition of the present invention is excellent in thermal conductivity and excellent in workability and storage stability. Moreover, since the sealing material of this invention also consists of the said polyurethane resin composition, it is excellent in thermal conductivity. Furthermore, since the electrical / electronic component of the present invention is resin-sealed using the above-described sealing material, it exhibits high heat dissipation, is resin-sealed in detail, and has high reliability even in a high-temperature and high-humidity environment. Indicates.

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

1. Polyurethane resin composition The polyurethane resin composition of the present invention comprises a polyurethane resin (C) comprising a polyol compound (A) having two or more hydroxyl groups and a polyisocyanate compound (B), and an inorganic filler (D). It is a resin composition, Comprising: The said inorganic filler (D) contains the following (D1) and (D2);
(D1): Ratio (D ₉₀ ) / (D of the volume-based cumulative 90% particle diameter (D ₉₀ ) and the volume-based cumulative 10% particle diameter (D ₁₀ ) in the particle size distribution measured by the laser diffraction scattering method. ₁₀ ) is 1 to 5 and the volume-based cumulative 50% particle diameter (D ₅₀ ) is 0.1 to 3 μm aluminum hydroxide particles;
(D2): Ratio (D ₉₀ ) / (D) of volume-based cumulative 90% particle diameter (D ₉₀ ) and volume-based cumulative 10% particle diameter (D ₁₀ ) in the particle size distribution measured by the laser diffraction scattering method. ₁₀ ) is an aluminum hydroxide particle having 1 to 15 and a volume-based cumulative 50% particle diameter (D ₅₀ ) of 5 to 15 μm.

  Since the polyurethane resin composition of this invention contains an inorganic filler (D), it is excellent in thermal conductivity. Moreover, since the polyurethane resin composition of this invention is a structure in which an inorganic filler (D) contains the said specific (D1) and (D2), aggregation of an inorganic filler (D) is suppressed, An increase in the viscosity of the polyurethane resin composition due to the inclusion of the inorganic filler (D) is suppressed. For this reason, the polyurethane resin composition of this invention is excellent in workability | operativity, and shows the outstanding storage stability.

  Moreover, since the sealing material of this invention also consists of the said polyurethane resin composition, it is excellent in thermal conductivity. Furthermore, since the electrical / electronic component of the present invention is resin-sealed using the above-described sealing material, it exhibits high heat dissipation, is resin-sealed in detail, and has high reliability even in a high-temperature and high-humidity environment. Can be shown.

(Polyol compound (A) having two or more hydroxyl groups)
The polyol compound having two or more hydroxyl groups used in the present invention is not particularly limited as long as it is a polyol having two or more hydroxyl groups, and various types of those conventionally used as a polyol component in a polyurethane resin composition can be used. It is. In the present specification, the polyol compound having two or more hydroxyl groups may be simply referred to as “polyol”.

  Examples of the polyol compound having two or more hydroxyl groups include ethylene glycol, 1,3-propanediol, 1,2-propanediol, 2methyl 1,3-propanediol, 1,4-butanediol, 1,3- Butanediol, 1,4-pentanediol, 1,5-pentanediol, 1,6-hexanediol, 1,5-hexanediol, 1,2-hexanediol, 2,5-hexanediol, octanediol, nonanediol, Decanediol, diethylene glycol, triethylene glycol, dipropylene glycol, cyclohexanediol, trimethylolpropane, glycerin, 2-methylpropane-1,2,3-triol, 1,2,6-hexanetriol, pentaerythlit, polylactone Diol, po Lactone triol, ester glycol, polyester polyol, polyether polyol, polycarbonate polyol, polybutadiene polyol, acrylic polyol, silicone polyol, fluorine polyol, polytetramethylene glycol, polypropylene glycol, polyethylene glycol, polycaprolactone polyol, castor oil-based polyol, dimer acid Based polyols and the like.

  The polyol compound (A) having two or more hydroxyl groups may be used alone or in combination of two or more.

  Among the polyol compounds having two or more hydroxyl groups, it is preferable to use castor oil-based polyol (A1) and / or polybutadiene polyol (A2).

  Examples of the castor oil-based polyol (A1) include castor oil and castor oil derivatives.

  As the castor oil derivative, castor oil fatty acid; castor oil or hydrogenated castor oil hydrogenated to castor oil fatty acid; transesterified product of castor oil and other fats and oils; reaction product of castor oil and polyhydric alcohol; castor oil An esterification reaction product of a fatty acid and a polyhydric alcohol; those obtained by addition polymerization of an alkylene oxide to these. Among the above castor oil-based polyols, it is preferable to use castor oil.

  The molecular weight of the castor oil-based polyol (A1) is usually in the range of 100 to 4,000, preferably in the range of 300 to 2,500.

  In the castor oil-based polyol, the hydroxyl group content is usually in the range of 30 to 500 mgKOH / g, preferably in the range of 100 to 200 mgKOH / g, as the hydroxyl value.

  Specifically, as castor oil-based polyol (A1), Eulic H-30 (hydroxyl value 160, functional group number 3), Eulic H-57 (hydroxyl value 100, functional group number 3), Eulic H- manufactured by Ito Oil Co., Ltd. 52 (hydroxyl value 200, functional group number 3), castor oil (hydroxyl value 160, functional group number 3), and the like.

  Although the compounding quantity of the said castor oil-type polyol (A1) does not have a restriction | limiting in particular, It is preferable that it is 0.5-30 mass% in a polyurethane resin composition, and it is more preferable that it is 1-25 mass%. 5 to 20% by mass is more preferable.

  The said castor oil-type polyol (A1) may be used independently, and may mix and use 2 or more types.

  As said polybutadiene polyol (A2), what has a polybutadiene structure and two hydroxyl groups in a molecule | numerator should just be mentioned, and what has a hydroxyl group at the both ends of a chain | strand-shaped polybutadiene structure is especially preferable.

  Examples of the polybutadiene polyol (A2) include poly (1,4-butanediene) polyol, poly (1,2-butadiene) polyol, poly (1,2- / 1,4-butadiene) polyol, and the like. The poly (1,2- / 1,4-butadiene) polyol has a repeating unit composed of polybutadiene having 60 to 90 mol% of 1,4 bonds and 10 to 40 mol% of 1,2 bonds, The number of repetitions is 10 to 14, and examples include polyols having hydroxyl groups at both ends. That is, the polybutadiene polyol may have a polybutadiene structure in which 1,3-butadiene is trans 1,4-bonded, or has a polybutadiene structure in which 1,3-butadiene is cis 1,4-bonded. Alternatively, it may have a polybutadiene structure in which 1,3-butadiene is bonded to 1,2. Moreover, you may have a polybutadiene structure in which these bonds were mixed.

  The molecular weight of the polybutadiene polyol (A2) is preferably 800 to 4800, and more preferably 1200 to 3000.

  The polybutadiene polyol (A2) used in the present invention may be a hydrogenated polybutadiene polyol. Examples of the hydrogenated polybutadiene polyol include those disclosed in JP-A-2-298574. Hydrogenated polybutadiene polyol is obtained by hydrogenation of the above polybutadiene polyol.

  The polybutadiene polyol (A2) has an average hydroxyl value determined according to JIS K1557-1 of preferably 20 to 250 mgKOH / g, and more preferably 50 to 120 mgKOH / g.

  500-5000 are preferable and, as for the number average molecular weight of the said polybutadiene polyol (A2), 1000-3500 are more preferable.

  In the present specification, the number average molecular weight can be measured by a gel permeation chromatography (GPC) method (polystyrene conversion). Specifically, the number average molecular weight by the GPC method is Shodex GPC System 21 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. Measured at a column temperature of 40 ° C. using NMP as a mobile phase, and can be calculated using a standard polystyrene calibration curve.

  As the polybutadiene polyol (A2) used in the present invention, specifically, conventionally known ones used for polyurethane resins can be used, and commercially available products may be used. Examples of commercially available products include polybutadiene diols mainly having repeating units of 1,4 bonds (for example, Poly bd (trademark) R-15HT, Poly bd (trademark) R-45HT (both manufactured by Idemitsu Kosan Co., Ltd.)). And poly (1,2-butadiene) glycol (for example, G-1000, G-2000, G-3000 (all manufactured by Nippon Soda Co., Ltd.)) mainly having repeating units of 1,2 bonds.

  Hydrogenated polybutadiene diols include hydrogenated polybutadiene diols mainly having 1,4 bond repeating units (for example, Polytail H and Polytail HA (both manufactured by Mitsubishi Chemical Corporation)), and 1,2 bond repeating units. And hydrogenated polybutadiene diol (for example, GI-1000, GI-2000, GI-3000 (all trade names: manufactured by Nippon Soda Co., Ltd.)).

  Among the polybutadiene polyols (A2) used in the present invention, it is preferable to use R-15HT and R-45HT.

  The blending amount of the polybutadiene polyol (A2) is not particularly limited, but is preferably 0.5 to 30% by mass, more preferably 1 to 25% by mass in the polyurethane resin composition. More preferably, it is 20 mass%.

  The said polybutadiene polyol (A2) may be used independently, and 2 or more types may be mixed and used for it.

  In the polyurethane resin composition of the present invention, the blending amount of the polyol compound (A) having two or more hydroxyl groups used is not particularly limited, but among them, the polyurethane resin composition is preferably 0.5 to 100% by mass. 30 mass% is preferable and 1-25 mass% is more preferable.

  The polyol component having two or more hydroxyl groups preferably contains castor oil-based polyol (A1) and polybutadiene polyol (A2). In this case, the content of the castor oil-based polyol (A1) with respect to 100% by mass of the polyol component (A) having two or more hydroxyl groups is preferably 50% by mass or less. When the polyol component having the above blending ratio is used, the compatibility with the polyisocyanate component is excellent, the viscosity of the polyurethane resin composition is lowered, and the workability can be further improved.

(Polyisocyanate compound (B))
The polyisocyanate compound (B) used in the present invention is not particularly limited as long as it is a compound having two or more isocyanate groups, and a known polyisocyanate compound can be used.

  Among these, it is preferable to use an isocyanurate-modified product of a polyisocyanate compound, and when the isocyanate group-containing compound contains an isocyanurate-modified product of a polyisocyanate compound, the polyurethane resin composition has excellent heat resistance. .

  Examples of such isocyanurate-modified products of polyisocyanate compounds include isocyanurate-modified compounds of aliphatic polyisocyanate compounds, alicyclic polyisocyanate compounds, aromatic polyisocyanate compounds, araliphatic polyisocyanate compounds, and the like. .

  Examples of the aliphatic polyisocyanate compound include tetramethylene diisocyanate, dodecamethylene diisocyanate, hexamethylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, 2,4,4-trimethylhexamethylene diisocyanate, lysine diisocyanate, 2-methylpentane- Examples include 1,5-diisocyanate and 3-methylpentane-1,5-diisocyanate.

  Examples of the alicyclic polyisocyanate compound include isophorone diisocyanate, hydrogenated xylylene diisocyanate, 4,4′-dicyclohexylmethane diisocyanate, 1,4-cyclohexane diisocyanate, methylcyclohexylene diisocyanate, 1,3-bis (isocyanatomethyl) cyclohexane, and the like. Is mentioned.

  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, Examples include 5-naphthylene diisocyanate, xylylene diisocyanate, 1,3-phenylene diisocyanate, and 1,4-phenylene diisocyanate.

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

  As the isocyanurate-modified product of the polyisocyanate compound, an isocyanurate-modified product of an aliphatic polyisocyanate compound, an alicyclic polyisocyanate compound, or an aromatic polyisocyanate compound is preferable, and among them, an isocyanate of hexamethylene diisocyanate or diphenylmethane diisocyanate. A nurate modified product is more preferable.

  Examples of commercially available isocyanate group-containing compounds containing a polyisocyanate compound isocyanurate-modified product include Duranate TLA-100 (HDI isocyanurate Asahi Kasei Chemicals), Coronate HX (HDI isocyanurate Nippon Polyurethane). It is done.

  The above-mentioned polyisocyanate compound isocyanurate-modified products may be used alone or in admixture of two or more.

  The polyisocyanate compound (B) may contain other polyisocyanate compounds in addition to the isocyanurate-modified products of the polyisocyanate compounds. Examples of other polyisocyanate compounds include the above-mentioned aliphatic polyisocyanate compounds, alicyclic polyisocyanate compounds, aromatic polyisocyanate compounds, and araliphatic polyisocyanate compounds, and these polyisocyanate compounds, These allophanate modified bodies etc. are mentioned.

  In the polyurethane resin composition of the present invention, the blending amount of the polyisocyanate compound (B) to be used is not particularly limited, but among them, the polyol compound (A) having two or more hydroxyl groups is 1 to 100% by mass. 50 mass% is preferable and 5-40 mass% is more preferable.

  In the polyurethane resin composition of the present invention, the NCO / OH ratio between the isocyanate group-containing compound and the hydroxyl group-containing compound is preferably 0.6 to 2.0, and preferably 0.7 to 1.5. It is more preferable.

(Polyurethane resin (C))
The polyurethane resin composition of the present invention contains a polyurethane resin (C) composed of the polyol compound (A) having two or more hydroxyl groups and the polyisocyanate compound (B). The polyurethane resin (C) is a polyurethane resin obtained by mixing the polyol compound (A) having two or more hydroxyl groups and the polyisocyanate compound (B), so that these components generate urethane bonds by a urethane reaction. (C).

  The method of mixing the polyol compound (A) having two or more hydroxyl groups and the polyisocyanate compound (B) is not particularly limited, and contains a polyol compound (A) having two or more hydroxyl groups as described later. What is necessary is just to mix by the method etc. which mix a 1st component and the 2nd component containing a polyisocyanate compound (B).

(Inorganic filler (D))
The polyurethane resin composition of the present invention contains the following aluminum hydroxide particles (D1) and (D2).
(D1): Ratio (D ₉₀ ) / (D of the volume-based cumulative 90% particle diameter (D ₉₀ ) and the volume-based cumulative 10% particle diameter (D ₁₀ ) in the particle size distribution measured by the laser diffraction scattering method. ₁₀ ) is 1 to 5 and the volume-based cumulative 50% particle diameter (D ₅₀ ) is 0.1 to 3 μm aluminum hydroxide particles;
(D2): Ratio (D ₉₀ ) / (D) of volume-based cumulative 90% particle diameter (D ₉₀ ) and volume-based cumulative 10% particle diameter (D ₁₀ ) in the particle size distribution measured by the laser diffraction scattering method. ₁₀ ) is an aluminum hydroxide particle having 1 to 15 and a volume-based cumulative 50% particle diameter (D ₅₀ ) of 5 to 15 μm.

The volume-based cumulative 50% particle diameter (D ₅₀ ) is a particle diameter (median diameter) at a volume-based cumulative 50% in a particle size distribution measured by a laser diffraction / scattering method. The volume-based cumulative 50% particle size (D ₅₀ ) is a particle size at which the cumulative value is 50% in a cumulative curve obtained by obtaining a particle size distribution on a volume basis and setting the total volume to 100%. Also shown.

Similarly, the 10% particle size (D ₁₀ ) and the 90% particle size (D ₉₀ ) are a volume-based cumulative 10% particle size and a volume-based cumulative 90% particle size, and the total volume of the obtained particle size distribution is 100. In the cumulative curve with%, the particle size at the point where the cumulative value becomes 10% and 90% is shown. Therefore, the ratio (D ₉₀ / D ₁₀ ) between the 90% particle size (D ₉₀ ) and the 10% particle size (D ₁₀ ) can be considered as an index indicating the breadth of the particle size distribution. As the value of D ₉₀ / _{D 10} is large, it has a broad particle size distribution. _Moreover, as the D 90 _{/ D 10} is closer to 1, having a particle size distribution close to monodispersion.

(D1) is a ratio (D ₉₀ ) / volume-based cumulative 90% particle diameter (D ₉₀ ) to volume-based cumulative 10% particle diameter (D ₁₀ ) / D in the particle size distribution measured by the laser diffraction scattering method. _{(D 10)} is 1-5. When (D ₉₀ ) / (D ₁₀ ) is larger than 5, the storage stability is lowered. The (D ₉₀ ) / (D ₁₀ ) is preferably 1 to 3.

The above (D1) has a volume-based cumulative 50% particle diameter (D ₅₀ ) (average particle diameter) of 0.1 to 3 μm in the particle size distribution measured by the laser diffraction scattering method. If (D ₅₀ ) is smaller than 0.1 μm, the thixotropic property is increased, and if it is larger than 3 μm, the storage stability is lowered. The (D ₅₀ ) is preferably 1 to 2 μm.

(D2) is the ratio (D ₉₀ ) / volume-based cumulative 90% particle diameter (D ₉₀ ) to volume-based cumulative 10% particle diameter (D ₁₀ ) / D in the particle size distribution measured by the laser diffraction scattering method. _{(D 10)} is 1-15. When it is larger than 15, the storage stability is lowered. The (D ₉₀ ) / (D ₁₀ ) is preferably 5-10.

The above (D2) has a volume-based cumulative 50% particle diameter (D ₅₀ ) (average particle diameter) of 5 to 15 μm in the particle size distribution measured by the laser diffraction scattering method. When (D ₅₀ ) is smaller than 5 μm, the viscosity is increased, and when it is larger than 15 μm, the storage stability is lowered. The (D ₅₀ ) is preferably 6 to 13 μm, and more preferably 7 to 12 μm.

The (D2) has both (D ₉₀ ) / (D ₁₀ ) of 5 to 10 and (D ₅₀ ) of 5 to 15 μm, which achieves both storage stability and suppression of increase in viscosity. It is preferable in that it can be performed.

  The inorganic filler (D) should just contain the said (D1) and (D2), and may contain the inorganic filler of the average particle diameter different from (D1) and (D2). Examples of the inorganic filler having an average particle diameter different from (D1) and (D2) include aluminum hydroxide, alumina, aluminum nitride, boron nitride, magnesium hydroxide, magnesium oxide, zeolite, and the like. Among these, aluminum hydroxide, alumina, magnesium oxide, aluminum nitride, and / or boron nitride are preferable because of excellent heat dissipation, and aluminum hydroxide and / or alumina are more preferable. Moreover, it is also preferable that the said inorganic filler (D) consists only of (D1) and (D2) at the point which is excellent in a flame retardance.

  The blending ratio of the inorganic filler (D1) and the inorganic filler (D2) is preferably 40:60 to 95: 5 (mass ratio), more preferably 60:40 to 95: 5 (mass ratio), and 70: 30-95: 5 (mass ratio) is still more preferable.

  45-85 mass% is preferable with respect to 100 weight% of polyurethane resin compositions, and, as for the compounding quantity of an inorganic filler (D), 50-80 mass% is more preferable, and 55-70 mass% is still more preferable.

  The shape of the inorganic filler (D) may be either spherical or indefinite.

Plasticizer (E)
The polyurethane resin composition of the present invention may further contain a plasticizer (E) as necessary.

  Examples of such a plasticizer (E) include phthalic acid esters such as dioctyl phthalate, diisononyl phthalate and diundecyl phthalate; adipic acid esters such as dioctyl adipate and diisononyl adipate; Castor oil-based esters such as triglyceride triglyceride and triglyceride triacetylate; trimellitic esters such as trioctyl trimellitate and triisononyl trimellitate; tetraoctyl pyromellitate, tetraisononyl pyromellitate, etc. And pyromellitic acid esters. Among these, diisononyl phthalate is preferable.

  It is preferable that content of the said plasticizer (E) is 0.01-30 mass% with respect to 100 mass% of polyurethane resin compositions, and it is more preferable that it is 1-20 mass%. By making content of a plasticizer in the said range, the mixing viscosity at the time of manufacture of a polyurethane resin composition can be made lower, without reducing the heat resistance of a polyurethane resin composition largely.

  The said plasticizer (E) may be used independently and may be used in mixture of 2 or more types.

Polymerization catalyst (F)
A polymerization catalyst (F) can be further blended in the polyurethane resin composition of the present invention.

  As a polymerization catalyst (F), a well-known polymerization catalyst can be used, For example, metal catalysts, such as an organic tin catalyst, an organic lead catalyst, and an organic bismuth catalyst, an amine catalyst etc. can be illustrated. Examples of the organic tin catalyst include dioctyltin dilaurate, dibutyltin diacetate, dibutyltin dilaurate, and dioctyltin diacetate. Examples of the organic lead catalyst include lead octylate, lead octenoate, lead naphthenate and the like. Examples of the organic bismuth catalyst include bismuth octylate and bismuth neodecanoate. As amine catalysts, diethylenetriamine, triethylamine, N, N-dimethylcyclohexylamine, N, N, N ′, N′-tetramethylethylenediamine, N, N, N ′, N ″, N ″ -pentamethyldiethylenetriamine, trimethylene Examples thereof include diamine, dimethylaminoethanol, bis (2-dimethylaminoethyl) ether and the like. In addition, as the polymerization catalyst, an organometallic compound, a metal complex compound, or the like may be used. The content of the polymerization catalyst (F) is preferably 0.00001 to 10% by mass and more preferably 0.0001 to 5% by mass with respect to 100% by mass of the polyurethane resin composition.

  The said polymerization catalyst (F) may be used independently, and 2 or more types may be mixed and used for it.

Other components The polyurethane resin composition of the present invention may further comprise a tackifier, a colorant, a chain extender, a crosslinking agent, a filler, a pigment, a filler, a flame retardant, a urethanization catalyst, an ultraviolet absorber, if necessary. Various additives such as an antioxidant, a moisture absorbent, an antifoaming agent, an antifungal agent, and a silane coupling agent can be added.

  The amount of these components to be used may be appropriately determined from the range equivalent to the usual addition amount so as not to inhibit the desired properties of the polyurethane resin composition according to the purpose of use.

  When the polyurethane resin composition of the present invention is a liquid before curing, the viscosity is preferably 500 to 200,000 mPa · s, more preferably 500 to 100,000 mPa · s. By setting the viscosity within the above range, the polyurethane resin composition of the present invention can exhibit higher workability. In addition, in this specification, the viscosity of the polyurethane resin composition before hardening is a value measured by the measuring method mentioned later.

2. Manufacturing method of polyurethane resin composition It does not specifically limit as a method to manufacture the polyurethane resin composition of this invention, It can manufacture by the conventionally well-known method used as a method of manufacturing a polyurethane resin composition.

  As such a production method, for example, a step including preparing a component containing a polyol compound (A) having two or more hydroxyl groups and using it as a first component (Step 1), and a component including a polyisocyanate compound (B) are prepared. And a step including the step of forming the second component (step 2) and the step of mixing the first component and the second component to form the polyurethane resin composition (step 3).

  If the said 1st component contains the polyol compound (A) which has 2 or more of hydroxyl groups, and the said 2nd component contains the polyisocyanate compound (B), another component is 1st component or 2nd component. Either may be contained.

  For example, the structure in which the 1st component contains the polyol compound (A) which has 2 or more of hydroxyl groups, an inorganic filler, and the 2nd component contains a polyisocyanate compound (B) and a plasticizer is mentioned.

  The first component may contain a polyol compound having two or more hydroxyl groups, an inorganic filler, and a plasticizer, and the second component may contain a polyisocyanate compound. The first component has two or more hydroxyl groups. The polyol compound (A) having an antioxidant and the second component may contain a polyisocyanate compound (B) and an inorganic filler, and the first component is a polyol compound having two or more hydroxyl groups ( A) A polymerization catalyst may be contained, and the second component may be configured to contain a polyisocyanate compound (B) and an antifoaming agent.

  The polyurethane resin composition may be liquid before curing or may be cured. As a method of curing the polyurethane resin composition, by mixing the first component and the second component, the hydroxyl group-containing compound and the isocyanate group-containing compound react to form a polyurethane resin. Although the method of hardening with time is mentioned, you may make it harden | cure 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. Sealing material and electrical / electronic component The present invention is also a sealing material comprising the polyurethane resin composition. The encapsulant made of the polyurethane resin composition is excellent in hydrolysis resistance and flame retardancy, and even when used in a high temperature environment, the flame retardancy is suppressed from being reduced. It can be suitably used for electrical and electronic parts involving the. Examples of such electrical and electronic parts include transformers such as transformer coils, choke coils, and reactor coils, equipment control boards, and various sensors. Such electric and electronic parts are also one aspect of the present invention. The electric and electronic parts of the present invention can be used in electric washing machines, toilet seats, water heaters, water purifiers, baths, dishwashers, electric tools, automobiles, motorcycles, 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 examples are merely examples, and the present invention is not limited to the examples.

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

Polyol compound having two or more hydroxyl groups (A)
A1: Castor oil (trade name: castor oil, manufactured by Ito Oil Co., Ltd.)
A2: Polybutadiene polyol having an average hydroxyl value of 103 mgKOH / g (trade name: R-15HT, manufactured by Idemitsu Kosan Co., Ltd.)

Polyisocyanate compound (B)
B1: Isocyanurate modified product of hexamethylene diisocyanate (trade name: Duranate TLA-100, manufactured by Asahi Kasei Chemicals Corporation)
B2: Diphenylmethane diisocyanate (MDI) -based isocyanate (trade name: Millionate MTL, manufactured by Tosoh Corporation)

Inorganic filler (D)
D1-1: Aluminum hydroxide (Showa Denko H-42M D ₅₀ ; 1 μm, D90 / D10; 2)
D2-1: Aluminum hydroxide (Nippon Light Metal RF-2071 D ₅₀ ; 10 μm, D90 / D10; 8)
D2-2: Aluminum hydroxide (Showa Denko H-32 D ₅₀ ; 8 μm, D90 / D10; 13)

Plasticizer (E)
E: Diisononyl phthalate (DINP)
(Product name: DINP, manufactured by JPLUS)

Polymerization catalyst (F)
F: Dioctyltin dilaurate (Brand name: Neostan U-810, manufactured by Nitto Kasei Corporation)

Preparation of polyurethane resin composition <Examples 1 to 9 and Comparative Examples 1 to 7>
Various polyurethane resin compositions were prepared according to the following procedure according to the formulations shown in Tables 1 and 2.

  First, a polyol compound, an inorganic filler, and a plasticizer were added at the blending ratios shown in Tables 1 and 2, and the mixture was used at a speed of 2000 rpm for 3 minutes using a mixing machine (trade name: manufactured by Shintaro Co., Ltd.). After mixing at ° C., the mixture was cooled to room temperature to obtain a mixture (first component). Thereafter, using the obtained mixture (first component), the workability (settability and viscosity) was tested.

  Subsequently, the polyisocyanate compound and the polymerization catalyst (dioctyltin dilaurate) shown in Table 1 adjusted to 23 ° C. were added to the above mixture (first component), and mixed at 2000 rpm for 1 minute using the same mixer. Defoaming was performed to obtain polyurethane resin compositions of Examples and Comparative Examples.

  The following tests were performed on the obtained polyurethane resin composition or the first component.

Preparation of test piece (test piece) A polyurethane resin composition was injected into a 6 cm × 12 cm × 1 cm mold. Next, the polyurethane resin composition was heated at 80 ° C. for 16 hours and then allowed to cure at room temperature for 1 day. The obtained cured product was subjected to the following test and evaluated for thermal conductivity.

<Test>
Workability (liquid characteristics)
The workability (liquid property) can be evaluated from the sedimentation property and viscosity of a composition (first component) containing a polyol compound, an inorganic filler, and a plasticizer.

(Sedimentation)
225 cc of the first component was weighed, and the first component was allowed to stand at 60 ° C. for 1 week in a thermostatic bath (PH (H) -101 manufactured by ESPEC). Thereafter, the sedimentation property of the inorganic filler was evaluated according to the following evaluation criteria.
○: not settled and easily dispersible Δ: settled but redispersible ×: not redispersible

(viscosity)
The first component was mixed at 2000 rpm for 3 minutes using a mixer (trade name: Awatori Nertaro, manufactured by Shinki Co., Ltd.), and then adjusted to 23 ° C. The viscosity of the obtained first component was measured using a BH viscometer and evaluated according to the following evaluation criteria.
○: Viscosity is less than 15000 mPa · s Δ: Viscosity is 15,000 to 500,000 mPa · s
X: Viscosity exceeds 500000 mPa · s

The heat conductivity was measured about the polyurethane resin composition after hardened | cured material characteristic hardening.

(Thermal conductivity)
The thermal conductivity of a 6 cm × 12 cm × 1 cm test piece was measured using a Kyoto electronic device QTM-500 and evaluated according to the following evaluation criteria.
○: Thermal conductivity of 0.5 W / m · K or more ×: Thermal conductivity of less than 0.5 W / m · K The results are shown in Tables 1 and 2.

Claims (4)

A polyurethane resin composition containing a polyurethane resin (C) comprising a polyol compound (A) having two or more hydroxyl groups and a polyisocyanate compound (B), and an inorganic filler (D),
The said inorganic filler (D) contains the following (D1) and (D2), The polyurethane resin composition characterized by the above-mentioned;
(D1): Ratio (D ₉₀ ) / (D of the volume-based cumulative 90% particle diameter (D ₉₀ ) and the volume-based cumulative 10% particle diameter (D ₁₀ ) in the particle size distribution measured by the laser diffraction scattering method. ₁₀ ) is 1 to 5 and the volume-based cumulative 50% particle diameter (D ₅₀ ) is 0.1 to 3 μm aluminum hydroxide particles;
(D2): Ratio (D ₉₀ ) / (D) of volume-based cumulative 90% particle diameter (D ₉₀ ) and volume-based cumulative 10% particle diameter (D ₁₀ ) in the particle size distribution measured by the laser diffraction scattering method. ₁₀ ) is 5 to 10 , and the volume-based cumulative 50% particle diameter (D ₅₀ ) is ₅ to 15 μm. The polyol compound (A) having two or more hydroxyl groups contains a castor oil-based polyol (A1) and a polybutadiene polyol (A2), and the content of the (A1) with respect to (A) 100% by mass is as follows: is 50 wt% or less, the polyurethane resin composition according to claim 1. Sealing material made of a polyurethane resin composition according to claim 1 or 2. An electrical / electronic component sealed with a resin using the sealing material according to claim 3 .