JP7618279B2 - Polyurethane resin composition - Google Patents

Description

The present invention relates to a polyurethane resin composition.

In order to realize a low-energy society, polyurethane resins are required to be cured at low temperatures and have an improved durability.
Conventionally, organotin catalysts such as dioctyltin dilaurate or dibutyltin dilaurate have been widely used as catalysts for producing polyurethanes.
However, while these organotin catalysts exhibit good reaction promotion, they also promote the deterioration reaction of the urethane resin, which reduces the durability of the polyurethane resin.In addition, these organotin catalysts have the risk of being highly toxic to the human body and the environment.

Meanwhile, catalysts for polyurethane production that can replace organotin catalysts have been recently investigated (for example, Patent Document 1).
Patent Document 1 describes a two-liquid type polyurethane coating composition that contains a bismuth-based catalyst as a catalyst.
However, since the catalytic activity of the bismuth catalyst is lower than that of the organotin catalyst, it is necessary to use the bismuth catalyst at a high concentration during the curing step of the composition, and therefore, even if the bismuth catalyst is used, it is difficult to suppress the deterioration of the durability life or the deterioration of the physical properties (e.g., moisture resistance, electrical insulation, etc.) that are problems with the organotin catalyst.

JP 2016-084390 A

The objective of the present invention is to provide a polyurethane resin composition that has excellent moisture resistance and suppresses the deterioration of electrical insulation properties.

As a result of intensive research aimed at solving the above problems, the present inventors have discovered a polyurethane resin composition comprising (A) an isocyanate compound, (B) a hydroxyl group-containing compound, and (C) a polymerization catalyst,
The (B) hydroxyl group-containing compound has an average hydroxyl value of 20 to 150 mgKOH/g and an average functionality of 1.8 to 3.5,
The (B) hydroxyl group-containing compound includes a polyester polyol,
The polyester polyol is contained in an amount of 30% by mass to 100% by mass based on 100% by mass of the hydroxyl group-containing compound (B), and
It has been found that the above-mentioned problems can be solved by using a polyurethane resin composition in which the polymerization catalyst (C) is at least one catalyst selected from the group consisting of (C1) an organometallic catalyst, the metal of which is an element of Group 4 of the periodic table, and (C2) a reactive amine catalyst. The present invention has been completed based on this finding.

That is, the present invention relates to the following polyurethane resin composition, etc.
Item 1.
A polyurethane resin composition comprising (A) an isocyanate compound, (B) a hydroxyl group-containing compound, and (C) a polymerization catalyst,
The (B) hydroxyl group-containing compound has an average hydroxyl value of 20 to 150 mgKOH/g and an average functionality of 1.8 to 3.5,
The (B) hydroxyl group-containing compound includes a polyester polyol,
The polyester polyol is contained in an amount of 30% by mass to 100% by mass based on 100% by mass of the hydroxyl group-containing compound (B), and
The polyurethane resin composition, wherein the polymerization catalyst (C) is at least one selected from the group consisting of (C1) organometallic catalysts, in which the metal is an element of Group 4 of the periodic table, and (C2) reactive amine catalysts.
Item 2.
The (B) hydroxyl group-containing compound is
(B1) a polyol having a number average molecular weight of less than 1,200;
(B2) a polyester polyol having a number average molecular weight of 1200 or more, or (B3) a polyol (excluding polyester polyols) having a number average molecular weight of 1200 or more,
Item 2. The polyurethane resin composition according to Item 1, wherein a total amount of the polyester polyol contained in the (B1) polyol having a number average molecular weight of less than 1,200 and the (B2) polyester polyol having a number average molecular weight of 1,200 or more is 30% by mass to 100% by mass relative to 100% by mass of the (B) hydroxyl group-containing compound.
Item 3.
Item 2. The polyurethane resin composition according to Item 1, wherein the organometallic catalyst (C1), in which the metal is an element of Group 4 of the periodic table, is at least one selected from the group consisting of zirconium alkoxides, zirconium chelate complexes, titanium alkoxides, and titanium chelate complexes.
Item 4.
Item 2. The polyurethane resin composition according to Item 1, further comprising (D) a plasticizer.
Item 5.
Item 3. The polyurethane resin composition according to Item 2, wherein the (B3) polyol (excluding polyester polyol) having a number average molecular weight of 1,200 or more contains a polybutadiene polyol.
Item 6.
Item 2. The polyurethane resin composition according to item 1, wherein the polymerization catalyst (C) is a zirconium chelate complex.
Item 7.
Item 7. An encapsulant comprising the polyurethane resin composition according to any one of items 1 to 6.
Item 8.
Item 8. An electric/electronic component resin-sealed with the sealing material according to item 7.

The present invention provides a polyurethane resin composition that has excellent moisture resistance and suppresses the deterioration of electrical insulation properties.

The polyurethane resin composition of the present invention will be described in detail below. In this specification, the expressions "contain" and "comprise" include the concepts of "contain," "comprise," "consist essentially of," and "consist only of."

1. Polyurethane resin composition The polyurethane resin composition of the present invention is a polyurethane resin composition containing (A) an isocyanate compound, (B) a hydroxyl group-containing compound, and (C) a polymerization catalyst,
The (B) hydroxyl group-containing compound has an average hydroxyl value of 20 to 150 mgKOH/g and an average functionality of 1.8 to 3.5,
The (B) hydroxyl group-containing compound includes a polyester polyol,
The polyester polyol is contained in an amount of 30% by mass to 100% by mass based on 100% by mass of the hydroxyl group-containing compound (B), and
The (C) polymerization catalyst is at least one selected from the group consisting of (C1) organometallic catalysts, in which the metal is an element of Group 4 of the periodic table, and (C2) reactive amine catalysts.

The cured resin obtained by curing the polyurethane resin composition of the present invention has excellent moisture resistance and can suppress the deterioration of electrical insulation properties.

1-1. (A) Isocyanate Compound The (A) isocyanate compound is not particularly limited as long as it has two or more isocyanate groups, and various components that are used or can be used in polyurethane resin compositions can be used.

The isocyanate compound (A) is not particularly limited and may be, for example,
(A1) an aliphatic polyisocyanate compound,
(A2) an alicyclic polyisocyanate compound,
(A3) polyisocyanate compounds such as aromatic polyisocyanate compounds;
The modified polyisocyanate compound (a) (e.g.,
(a-1) an isocyanurate compound,
(a-2) a carbodiimide compound,
(a-3) adduct,
(a-4) biuret form,
(a-5) Allophanate, etc.);
The polynuclear derivative (b) of the polyisocyanate compound is also included.

(A1) Examples of aliphatic polyisocyanate compounds 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, and 3-methylpentane-1,5-diisocyanate, with 1,6-hexamethylene diisocyanate (HDI) being preferred.

In addition, the aliphatic polyisocyanate compound (A1) is preferably an isocyanurate of an aliphatic polyisocyanate compound (A1a-1). For example, in the present invention, an isocyanurate compound having an isocyanate group at its terminal, which is derived from 1,6-hexamethylene diisocyanate (hereinafter abbreviated as "HDI"), can be used as the isocyanurate-modified 1,6-hexamethylene diisocyanate. Specific examples of these include Duranate (registered trademark) TPA-100, TKA-100, TSA-100, TSS-100, TSE-100, and TLA-100 manufactured by Asahi Kasei Corporation; Desmodur (registered trademark) N3390 manufactured by Sumitomo Bayer Urethane Co., Ltd.; Coronate (registered trademark) EH manufactured by Nippon Polyurethane Co., Ltd.; Takenate D170N manufactured by Takeda Pharmaceutical Co., Ltd.; and Burnock (registered trademark) DN980 manufactured by Dainippon Ink and Chemicals, Inc. (DIC Corporation).

(A2) Examples of alicyclic polyisocyanate compounds include isophorone diisocyanate, hydrogenated xylylene diisocyanate, 4,4'-dicyclohexylmethane diisocyanate (hydrogenated 4,4'-diphenylmethane diisocyanate, HMDI), 1,4-cyclohexane diisocyanate, methylcyclohexylene diisocyanate, and 1,3-bis(isocyanatomethyl)cyclohexane.

The hydrogenated product of 4,4'-diphenylmethane diisocyanate used in the present invention is a polyisocyanate obtained by hydrogenating 4,4'-diphenylmethane diisocyanate (hereinafter abbreviated as MDI). A specific example of this is WANNATE (registered trademark) HMDI manufactured by Wanka Chemical Japan.

(A3) Examples of aromatic polyisocyanate compounds 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, dialkyldiphenylmethane diisocyanate, tetraalkyldiphenylmethane diisocyanate, α,α,α,α-tetramethylxylylene diisocyanate, and the like, and preferred are 2,2'-diphenylmethane diisocyanate, 2,4'-diphenylmethane diisocyanate, and 4,4'-diphenylmethane diisocyanate (MDI). A specific example of this is Millionate (registered trademark) MR-200 (a mixture of MDI and its polynuclear derivatives) manufactured by Tosoh Corporation.

(A3) An example of the modified aromatic polyisocyanate compound (a) is the (a-2) carbodiimide derivative of 4,4'-diphenylmethane diisocyanate (MDI). In the present invention, a polyisocyanate having a carbodiimide group derived from 4,4'-diphenylmethane diisocyanate (carbodiimide-modified MDI) can be used. A specific example of this is Millionate (registered trademark) MTL manufactured by Tosoh Corporation.

The viscosity of the (A) isocyanate compound varies depending on the type of isocyanate compound and whether it is modified or not, but is not particularly limited. For example, in the case of aromatic polyisocyanate compounds and their modified products and polynuclear products (preferably carbodiimide and polynuclear products of aromatic polyisocyanate compounds), the viscosity is, for example, 5 to 200 mPa·s, preferably 10 to 150 mPa·s, more preferably 15 to 100 mPa·s, and even more preferably 20 to 80 mPa·s at 25°C. As another example, in the case of aliphatic polyisocyanate compounds and their modified products and polynuclear products (preferably isocyanurate products of aliphatic polyisocyanate compounds), the viscosity is, for example, 100 to 3000 mPa·s, preferably 500 to 2500 mPa·s, more preferably 1000 to 2000 mPa·s, and even more preferably 1200 to 1700 mPa·s at 25°C.

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

As the (A) isocyanate compound, from the viewpoints of excellent moisture resistance and suppressing deterioration of electrical insulation, preferably, (Aa-1) an isocyanurate of a polyisocyanate compound (more preferably, (A1a-1) an isocyanurate of an aliphatic polyisocyanate compound),
(A3) an aromatic polyisocyanate compound (more preferably, 4,4'-diphenylmethane diisocyanate (MDI) or a polynuclear product of MDI, and a mixture of MDI and a polynuclear product of MDI);
(A3) A carbodiimide derivative of an aromatic polyisocyanate compound (more preferably, a polyisocyanate having a carbodiimide group derived from 4,4'-diphenylmethane diisocyanate (carbodiimide-modified MDI)) can be mentioned.

As the (A) isocyanate compound, 4,4'-diphenylmethane diisocyanate or a modified or polynuclear compound thereof is more preferable. Specifically,
(A3) An aromatic polyisocyanate compound (more preferably, 4,4'-diphenylmethane diisocyanate (MDI) or a polynuclear MDI, and a mixture of MDI and a polynuclear MDI) and a carbodiimide-modified product of 4,4'-diphenylmethane diisocyanate, i.e., a polyisocyanate having a carbodiimide group derived from 4,4'-diphenylmethane diisocyanate (carbodiimide-modified MDI) are more preferred.

Among these, preferred commercially available products of the (A) isocyanate compound include, for example, Duranate (registered trademark) TPA-100 (manufactured by Asahi Kasei Corporation), Millionate (registered trademark) MR-200 (manufactured by Tosoh Corporation), and Millionate (registered trademark) MTL (manufactured by Tosoh Corporation), with Millionate (registered trademark) MR-200 (manufactured by Tosoh Corporation) and Millionate (registered trademark) MTL (manufactured by Tosoh Corporation) being more preferred.

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

The content of the isocyanate compound (A) is not particularly limited as long as it is an amount that can be used in the polyurethane resin composition. The content is, for example, usually 0.01 to 50 mass%, preferably 0.1 to 35 mass%, more preferably 1 to 30 mass%, and particularly preferably 1.5 to 25 mass%, based on 100 mass% of the polyurethane resin composition.
The content of the isocyanate compound (A) is, for example, 5 to 75 parts by mass, preferably 8 to 70 parts by mass, and more preferably 10 to 65 parts by mass, per 100 parts by mass of the hydroxyl group-containing compound (B).

When two or more types of (A) isocyanate compounds are blended in the polyurethane resin composition of the present invention, the total amount can be adjusted according to the content of the above-mentioned (A) isocyanate compound.

When the polyurethane resin composition of the present invention contains (A3) an aromatic polyisocyanate compound, the content thereof is usually 0.01 to 50 mass%, preferably 0.1 to 35 mass%, and more preferably 1 to 30 mass%, relative to 100 mass% of the polyurethane resin composition.

The amount of (A) isocyanate compound and (B) hydroxyl group-containing compound described below is such that the NCO/OH ratio (INDEX), which is the ratio of the number of moles of isocyanate groups in the isocyanate compound to the total number of moles of hydroxyl groups in the hydroxyl group-containing compound, is in the range of 0.5 to 1.5, preferably 0.7 to 1.3, and more preferably 0.8 to 1.1.

1-2. (B) Hydroxyl-Containing Compound The average hydroxyl value of the (B) hydroxyl-containing compound is usually 20 to 150 mgKOH/g, preferably 50 to 147 mgKOH/g, and more preferably 80 to 145 mgKOH/g.
In the present specification, the "average hydroxyl value" refers to the hydroxyl value of one hydroxyl-containing compound when one type of hydroxyl-containing compound is used alone, and refers to the average hydroxyl value calculated by multiplying the hydroxyl values of the multiple hydroxyl-containing compounds by their blending ratio and adding them up when two or more types are used in combination. In this specification, the hydroxyl value is measured in accordance with Method A of JIS K1557-1:2007.

The average number of functional groups of the hydroxyl group-containing compound (B) is usually 1.8 to 3.5, preferably 1.9 to 3, and more preferably 2 to 2.5.
In this specification, the term "average number of functional groups" refers to the number of functional groups per molecule. In the case of a hydroxyl-containing compound, it is the average number of hydroxyl groups per molecule of the hydroxyl-containing compound.

The hydroxyl group-containing compound (B) is not particularly limited as long as it has an average hydroxyl value of 20 to 150 mgKOH/g and the average number of functional groups can be adjusted to 1.8 to 3.5, and it is possible to use compounds that are conventionally used as polyol components in polyurethane resin compositions.

The hydroxyl group-containing compound (B) includes a polyester polyol (B-1).
Examples of the polyester polyol (B-1) include castor oil polyols and condensation type polyester polyols.

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

Examples of the above-mentioned castor oil derivatives include castor oil fatty acids; hydrogenated castor oil obtained by hydrogenating castor oil or castor oil fatty acids; transesterification products of castor oil and other fats and oils; reaction products of castor oil and polyhydric alcohols; esterification products of castor oil fatty acids and polyhydric alcohols; and compounds obtained by addition polymerization of these with alkylene oxides. Among the above-mentioned castor oil-based polyols, it is preferable to use esterification products of castor oil or castor oil fatty acids and polyhydric alcohols.

The hydrogenated castor oil is, for example, that disclosed in JP-A-2-298574. Hydrogenated castor oil can be obtained by hydrogenating the castor oil-based polyol.

The average hydroxyl value of the above castor oil-based polyol is preferably 20 to 400 mg KOH/g, and more preferably 50 to 200 mg KOH/g.

The average number of functional groups of the castor oil-based polyol is usually 1.5 to 3.5, more preferably 1.8 to 3, and even more preferably 2 to 2.7.

The number average molecular weight (Mn) of the above castor oil-based polyol is usually in the range of 100 to 5000, preferably in the range of 200 to 2500, and more preferably in the range of 300 to 2000.

In this specification, the number average molecular weight (Mn) can be measured by gel permeation chromatography (GPC) (polystyrene equivalent). Specifically, the number average molecular weight by GPC is measured using a Shodex GPC System 21 manufactured by Showa Denko K.K. as a measuring device, a Shodex LF-804/KF-803/KF-804 manufactured by Showa Denko K.K. as a column, NMP as a mobile phase, at a column temperature of 40°C, and can be calculated using a calibration curve of standard polystyrene.

The condensation type polyester polyol may be, for example, a polyester polyol obtained by condensing a low molecular weight polyol having a number average molecular weight (Mn) of less than 300 with a polycarboxylic acid having 2 to 10 carbon atoms or an ester-forming derivative thereof.
Among the low molecular weight polyols having a number average molecular weight (Mn) of less than 300 used for the condensation type polyester polyol, preferred are ethylene glycol, propylene glycol, 1,4-butanediol, neopentyl glycol, 1,6-hexane glycol, low molar adducts of bisphenol A with ethylene oxide (hereinafter abbreviated as "EO") or 1,2- or 1,3-propylene oxide (hereinafter abbreviated as "PO"), and mixtures thereof.

Examples of polycarboxylic acids having 2 to 10 carbon atoms or their ester-forming derivatives used in condensation polyester polyols include aliphatic dicarboxylic acids (succinic acid, adipic acid, azelaic acid, sebacic acid, fumaric acid, maleic acid, etc.), alicyclic dicarboxylic acids (dimer acid, etc.), aromatic dicarboxylic acids (terephthalic acid, isophthalic acid, phthalic acid, etc.), trivalent or higher polycarboxylic acids (trimellitic acid, pyromellitic acid, etc.), their anhydrides (succinic anhydride, maleic anhydride, phthalic anhydride, trimellitic anhydride, etc.), their acid halides (adipic acid dichloride, etc.), their low molecular weight alkyl esters (dimethyl succinate, dimethyl phthalate, etc.), and mixtures of these.

Specific examples of condensation type polyester polyols include polyethylene adipate diol, polybutylene adipate diol, polyhexamethylene adipate diol, polyethylene terephthalate diol, polyhexamethylene isophthalate diol, polyethylene terephthalate diol, polyhexamethylene terephthalate diol, polyneopentyl terephthalate diol, polyneopentyl adipate diol, polyethylene propylene adipate diol, polyethylene butylene adipate diol, polybutylene Examples of such diols include hexamethylene adipate diol, polydiethylene adipate diol, poly(polytetramethylene ether) adipate diol, poly(3-methylpentylene adipate) diol, polyethylene azelate diol, polyethylene sebacate diol, polybutylene azelate diol, polybutylene sebacate diol, poly(butylene adipate/butylene terephthalate) copolymer diol, and poly(3-methylpentylene adipate/3-methylpentylene terephthalate) copolymer diol.

Commercially available condensation polyester polyols include SunEstar 2610 [polyethylene adipate diol with Mn=1,000, manufactured by Sanyo Chemical Industries, Ltd.], SunEstar 4620 [polytetramethylene adipate diol with Mn=2,000], SunEstar 2620 [polyethylene adipate diol with Mn=2,000, manufactured by Sanyo Chemical Industries, Ltd.], Kuraray Polyol P-2010 [poly-3-methyl-1,5-pentylene adipate diol with Mn=2,000], and Kuraray Polyol P-3010 [poly-3-methyl-1,5-pentylene adipate diol with Mn=3,000]. p-diol], Kuraray Polyol P-6010 [poly-3-methyl-1,5-pentylene adipate diol of Mn=6000], Kuraray Polyol P-520 [poly-3-methyl-1,5-pentylene terephthalate diol of Mn=500], Kuraray Polyol P-1020 [poly-3-methyl-1,5-pentylene terephthalate diol of Mn=1000], Kuraray Polyol P-2020 [poly-3-methyl-1,5-pentylene terephthalate diol of Mn=2000], Kuraray Polyol P-530 [poly-3-methyl-1, 5-pentylene isophthalate diol], Kuraray Polyol P-1030 [poly-3-methyl-1,5-pentylene isophthalate diol of Mn=1000], Kuraray Polyol P-2030 [poly-3-methyl-1,5-pentylene isophthalate diol of Mn=2000], Kuraray Polyol P-1011 [poly(3-methyl-1,5-pentylene adipate/3-methyl-1,5-pentylene terephthalate) copolymer diol of Mn=1,000], Kuraray Polyol P-2011 [poly(3-methyl-1,5-pentylene adipate/3-methyl-1,5-pentylene terephthalate) copolymer diol of Mn=2000] Poly(3-methyl-1,5-pentylene adipate/3-methyl-1,5-pentylene isophthalate) copolymer diol with Mn=1000, Kuraray Polyol P-1012 [Poly(3-methyl-1,5-pentylene adipate/3-methyl-1,5-pentylene isophthalate) copolymer diol with Mn=2000], Kuraray Polyol P-2050 [Poly-3-methyl-1,5-pentylene sebacate diol with Mn=2000], etc.

The average hydroxyl value of the condensation type polyester polyol is preferably 20 to 400 mg KOH/g, and more preferably 50 to 200 mg KOH/g.

The average number of functional groups of the condensation type polyester polyol is usually 1.5 to 3.5, more preferably 1.8 to 3, and even more preferably 2 to 2.7.

The number average molecular weight (Mn) of the condensation type polyester polyol is usually in the range of 100 to 6000, preferably in the range of 200 to 4000, and more preferably in the range of 300 to 2500.

As the polyester polyol (B-1), castor oil-based polyol is preferred. Commercially available castor oil-based polyols include URIC H-30 and URIC Y-403 manufactured by Ito Oil Mills, Ltd.

The polyester polyol (B-1) may be used alone or in combination of two or more.
The amount of the polyester polyol (B-1) is usually 30% by mass to 100% by mass, preferably 40% by mass to 95% by mass, and more preferably 50% by mass to 90% by mass, based on 100% by mass of the hydroxyl group-containing compound (B).
Here, it is preferable to use a mixture of two or more kinds of the polyester polyol (B-1) above.
When the above polyester polyol (B-1) is used, for example, as a mixture of two types, the polyester polyol (B-1) can contain a first polyester polyol (B-1-1) and a second polyester polyol (B-1-2).
The content of the first polyester polyol (B-1-1) is usually 5% by mass to 70% by mass, preferably 10% by mass to 60% by mass, and more preferably 20% by mass to 50% by mass, based on 100% by mass of the hydroxyl group-containing compound (B).
The content of the second polyester polyol (B-1-2) is usually 25% by mass to 95% by mass, preferably 35% by mass to 80% by mass, and more preferably 40% by mass to 70% by mass, relative to 100% by mass of the hydroxyl group-containing compound (B).
In addition, when the above-mentioned (B-1) polyester polyol is used in a mixture of three types, the (B-1) polyester polyol can contain a first polyester polyol (B-1-1), a second polyester polyol (B-1-2), and a third polyester polyol (B-1-3).
The content of the first polyester polyol (B-1-1) is usually 5% by mass to 70% by mass, preferably 10% by mass to 55% by mass, and more preferably 20% by mass to 50% by mass, based on 100% by mass of the hydroxyl group-containing compound (B).
The content of the second polyester polyol (B-1-2) is usually 20% by mass to 70% by mass, preferably 30% by mass to 55% by mass, and more preferably 40% by mass to 50% by mass, based on 100% by mass of the hydroxyl group-containing compound (B).
The content of the third polyester polyol (B-1-3) is usually 3% by mass to 25% by mass, preferably 5% by mass to 20% by mass, and more preferably 10% by mass to 15% by mass, relative to 100% by mass of the hydroxyl group-containing compound (B).

The hydroxyl group-containing compound (B) used in the present invention may further contain a polyol compound other than the polyester polyol (B-1) described above. Examples of polyol compounds other than the polyester polyol (B-1) described above include polyolefin polyol (B-2) and polyether polyol (B-3).

(B-2) Polyolefin-Based Polyol (B-2) is, for example, a polymer of a radically polymerizable monomer having two or more unsaturated double bonds, or a copolymer of such a radically polymerizable monomer with another radically polymerizable monomer, and has two or more hydroxyl groups.

(B-2) Polyolefin polyols include polyolefin polyols (e.g., polybutadiene polyols, polyisoprene polyols) and hydrogenated polyolefin polyols (hydrogenated polyolefin polyols), etc.

Examples of polyolefin polyols include polybutadiene polyols and polyisoprene polyols. Commercially available polyolefin polyols include polybutadiene polyols [Nisso-PBG series (G-1000, G-2000, G-3000, etc.) manufactured by Nippon Soda Co., Ltd., Poly Bd (registered trademark) series (R-45M, R-45HT, CS-15, CN-15, etc.) manufactured by ARCO Corporation of the United States], and polyisoprene polyols [Poly ip manufactured by Idemitsu Kosan Co., Ltd.].

Examples of hydrogenated polyolefin polyols (hydrogenated polyolefin polyols) include hydrogenated polybutadiene polyols and hydrogenated polyisoprene polyols. Commercially available hydrogenated polyolefin polyols include hydrogenated polybutadiene polyols (NISSO-PBGI series (GI-1000, GI-2000, GI-3000, etc.) manufactured by Nippon Soda Co., Ltd.), hydrogenated polyolefin polyols (Epole manufactured by Idemitsu Kosan Co., Ltd.), etc.

The hydroxyl value of the polyolefin polyol (B-2) is preferably 10 to 120 mgKOH/g, more preferably 25 to 110 mgKOH/g, and particularly preferably 40 to 100 mgKOH/g.

The average number of functional groups of the polyolefin polyol (B-2) is usually 1.5 to 5, preferably 1.6 to 3, and more preferably 1.7 to 2.5.

The number average molecular weight (Mn) of the polyolefin polyol (B-2) is usually in the range of 100 to 5000, preferably in the range of 1000 to 4000, and more preferably in the range of 1500 to 3500.

The hydroxyl group content of the polyolefin polyol (B-2) is not particularly limited, but is usually 0.001 to 3 mol/kg, preferably 0.01 to 2 mol/kg, and more preferably 0.1 to 1.2 mol/kg.

The viscosity of the polyolefin polyol (B-2) (30° C.) is usually in the range of 0.01 to 500 Pa·s, preferably in the range of 0.1 to 300 Pa·s, and more preferably in the range of 1 to 150 Pa·s.
do.

The iodine value of the polyolefin polyol (B-2) is usually in the range of 1 to 1000 g/100 g, preferably in the range of 5 to 500 g/100 g, and more preferably in the range of 10 to 100 g/100 g.

The polyolefin-based polyol (B-2) may be used alone or in combination of two or more kinds.
Among these, the polyolefin polyol (B-2) is preferably a polybutadiene polyol, and more preferably a polybutadiene polyol having a number average molecular weight (Mn) of 1,200 or more and a hydroxyl value of 20 to 150 mgKOH/g.

The content of (B-2) polyolefin polyol is preferably 0 to 70 parts by mass, more preferably 5 to 60 parts by mass, and even more preferably 10 to 55 parts by mass, per 100 parts by mass of (B) hydroxyl group-containing compound.

(B-3) Polyether Polyol The polyether polyol is not particularly limited, and examples thereof include polyether polyols obtained by addition polymerization of alkylene oxides such as ethylene oxide, propylene oxide, butylene oxide, etc., using water, low molecular weight polyols (propylene glycol, ethylene glycol, glycerin, trimethylolpropane, pentaerythritol, etc.), bisphenols (bisphenol A, etc.), dihydroxybenzenes (catechol, resorcin, hydroquinone, etc.) as initiators. Specific examples include polyethylene glycol, polypropylene glycol, polytetramethylene glycol, etc.

The hydroxyl value of the polyether polyol (B-3) is preferably 1 to 600 mgKOH/g, more preferably 10 to 400 mgKOH/g, and particularly preferably 25 to 150 mgKOH/g.

The average number of functional groups of the polyether polyol (B-3) is usually 1.5 to 5, preferably 2 to 4, and more preferably 1.8 to 3.5.

The number average molecular weight (Mn) of the polyether polyol (B-3) is usually in the range of 100 to 5,000, preferably in the range of 300 to 4,000, and more preferably in the range of 500 to 3,500.

The above (B-3) polyether polyols can be used alone or in combination of two or more.
Among these, polypropylene diol is preferred as the polyether polyol (B-3).

The content of (B-3) polyether polyol is preferably 0 to 70 parts by mass, more preferably 5 to 60 parts by mass, and even more preferably 10 to 55 parts by mass, per 100 parts by mass of (B) hydroxyl group-containing compound.

The hydroxyl group-containing compound (B) used in the present invention may further contain a polyol compound other than the above-mentioned polyester polyol (B-1), polyolefin polyol (B-2), and polyether polyol (B-3) (hereinafter referred to as "other polyols (B-4)").

(B-4) Examples of other polyols include dimer acid polyols; polycarbonate polyols; polycaprolactone polyols; acrylic polyols; aliphatic polyols; amine polyols; and hydrogenated versions of these polyols.

There are no particular limitations on the dimer acid polyol, and any known dimer acid polyol can be used.

The polycarbonate polyol is not particularly limited, and examples thereof include polycarbonate polyols obtained by polycondensation reaction of the above polyol components with phosgene; polycarbonate polyols obtained by transesterification condensation of the above polyol components with carbonate diesters such as dimethyl carbonate, diethyl carbonate, dipropyl carbonate, diisopropyl carbonate, dibutyl carbonate, ethyl butyl carbonate, ethylene carbonate, propylene carbonate, diphenyl carbonate, and dibenzyl carbonate; copolymer polycarbonate polyols obtained by using two or more of the above polyol components in combination; polycarbonate polyols obtained by esterification reaction of the above polycarbonate polyols with a carboxyl group-containing compound; Examples of the polycarbonate polyol include polycarbonate polyols obtained by etherification reaction of the various polycarbonate polyols with hydroxyl group-containing compounds; polycarbonate polyols obtained by transesterification reaction of the various polycarbonate polyols with ester compounds; polycarbonate polyols obtained by transesterification reaction of the various polycarbonate polyols with hydroxyl group-containing compounds; polyester-based polycarbonate polyols obtained by polycondensation reaction of the various polycarbonate polyols with dicarboxylic acid compounds; copolymerized polyether-based polycarbonate polyols obtained by copolymerizing the various polycarbonate polyols with alkylene oxides. The polycarbonate polyols can be referred to as polycarbonate diols.

There are no particular limitations on the polycaprolactone polyol, and examples include caprolactone-based polyester diols obtained by ring-opening polymerization of cyclic ester monomers such as ε-caprolactone and δ-valerolactone.

Examples of acrylic polyols include copolymers obtained by copolymerizing a hydroxyl group-containing acrylate with a copolymerizable vinyl monomer that is copolymerizable with the hydroxyl group-containing acrylate.

Examples of hydroxyl group-containing acrylates include 2-hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, hydroxybutyl (meth)acrylate, 2,2-dihydroxymethylbutyl (meth)acrylate, polyhydroxyalkyl maleate, polyhydroxyalkyl fumarate, etc., and preferably 2-hydroxyethyl (meth)acrylate, etc.

Examples of the copolymerizable vinyl monomer include C 1-12 alkyl (meth)acrylates such as methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, isopropyl (meth)acrylate, butyl (meth)acrylate, isobutyl (meth)acrylate, s-butyl (meth)acrylate, t-butyl (meth)acrylate, pentyl (meth)acrylate, isopentyl (meth)acrylate, hexyl (meth)acrylate, isononyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, and _cyclohexyl acrylate;
For example, aromatic vinyls such as styrene, vinyl toluene, and α-methyl styrene;
For example, vinyl cyanides such as (meth)acrylonitrile;
For example, vinyl monomers containing a carboxyl group, such as (meth)acrylic acid, fumaric acid, maleic acid, itaconic acid, etc., or alkyl esters thereof;
For example, alkane polyol poly(meth)acrylates such as ethylene glycol di(meth)acrylate, butylene glycol di(meth)acrylate, hexanediol di(meth)acrylate, oligoethylene glycol di(meth)acrylate, trimethylolpropane di(meth)acrylate, and trimethylolpropane tri(meth)acrylate;
For example, vinyl monomers containing an isocyanate group such as 3-(2-isocyanate-2-propyl)-α-methylstyrene can be mentioned.

Acrylic polyols can be obtained by copolymerizing these hydroxyl group-containing acrylates and copolymerizable vinyl monomers in the presence of a suitable solvent and polymerization initiator.

Acrylic polyols include, for example, silicone polyols and fluorine polyols.

Examples of silicone polyols include acrylic polyols blended with a silicone compound containing a vinyl group, such as γ-methacryloxypropyltrimethoxysilane, as a copolymerizable vinyl monomer in the copolymerization of the acrylic polyol described above.

Examples of fluorine polyols include acrylic polyols blended with fluorine compounds containing vinyl groups, such as tetrafluoroethylene and chlorotrifluoroethylene, as copolymerizable vinyl monomers in the copolymerization of the above-mentioned acrylic polyols.

The vinyl monomer modified polyol can be obtained by reacting the above-mentioned high molecular weight polyol with a vinyl monomer.

The aliphatic polyol is not particularly limited, and examples thereof include ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, 1,2-propanediol, 1,3-propanediol, dipropylene glycol, tripropylene glycol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 2,3-butanediol, 1,5-pentanediol, 1,5-hexanediol, 1,6-hexanediol, 2,5-hexanediol, 1,7-heptanediol, 1,8- Octanediol, 1,9-nonanediol, 1,10-decanediol, 1,11-undecanediol, 1,12-dodecanediol, 2-methyl-1,3-propanediol, neopentyl glycol, 2-butyl-2-ethyl-1,3-propanediol, 3-methyl-1,5-pentanediol, 2-ethyl-1,3-hexanediol, 2-methyl-1,8-octanediol, glycerin, trimethylolpropane, ditrimethylolpropane, tritrimethylolpropane, pentaerythritol, etc.

The amine polyol is not particularly limited, and examples thereof include diethanolamine, triethanolamine, and aliphatic amine polyols. Commercially available products of the aliphatic amine polyols include "Sannix NP-300" manufactured by Sanyo Chemical Industries, Ltd.

The (B) hydroxyl group-containing compound is
(B1) a polyol having a number average molecular weight of less than 1,200;
(B2) a polyester polyol having a number average molecular weight of 1200 or more, or (B3) a polyol having a number average molecular weight of 1200 or more (excluding polyester polyols),
The average hydroxyl value can be adjusted to 20 to 150 mgKOH/g, and the average functionality can be adjusted to 1.8 to 3.5.

The (B1) polyol having a number average molecular weight of less than 1,200 includes (B1a) polyester polyol having a number average molecular weight of less than 1,200 and (B1b) polyol having a number average molecular weight of less than 1,200 (excluding polyester polyols).
The (B) hydroxyl group-containing compound necessarily contains (B-1) polyester polyol.
Combination 1 including (B1a) a polyester polyol having a number average molecular weight of less than 1,200 and (B2) a polyester polyol having a number average molecular weight of 1,200 or more;
(B1a) a combination 2 including a polyester polyol having a number average molecular weight of less than 1,200 and (B3) a polyol having a number average molecular weight of 1,200 or more (excluding polyester polyols); and
Combination 3 including (B1b) a polyol having a number average molecular weight of less than 1,200 (excluding polyester polyols) and (B2) a polyester polyol having a number average molecular weight of 1,200 or more
There is.

As the (B1) polyol having a number average molecular weight of less than 1,200, (B1a) a polyester polyol having a number average molecular weight of less than 1,200 is preferable, and a castor oil-based polyol having a number average molecular weight of less than 1,200 is more preferable.
The (B2) polyester polyol having a number average molecular weight of 1200 or more is preferably a castor oil polyol having a number average molecular weight of 1200 or more, or a condensation type polyester polyol having a number average molecular weight of 1200 or more, and more preferably a condensation type polyester polyol having a number average molecular weight of 1200 or more.
The (B3) polyol (excluding polyester polyol) having a number average molecular weight of 1,200 or more is preferably a polyolefin polyol having a number average molecular weight of 1,200 or more, and more preferably a polybutadiene polyol having a number average molecular weight of 1,200 or more.

In the case of the above combination 1 ((B1a) polyester polyol having a number average molecular weight of less than 1200, and (B2) polyester polyol having a number average molecular weight of 1200 or more), the content of (B-1) polyester polyol in (B) hydroxyl group-containing compound is the total amount of (B1a) polyester polyol having a number average molecular weight of less than 1200 and (B2) polyester polyol having a number average molecular weight of 1200 or more, which is 100% by mass relative to 100% by mass of (B) hydroxyl group-containing compound.

In the case of the combination 2 ((B1a) polyester polyol having a number average molecular weight of less than 1200, and (B3) polyol having a number average molecular weight of 1200 or more (excluding polyester polyol)), the content of (B-1) polyester polyol in (B) hydroxyl group-containing compound is the content of (B1a) polyester polyol having a number average molecular weight of less than 1200, and is 30% by mass or more and less than 100% by mass relative to 100% by mass of (B) hydroxyl group-containing compound.

In the case of the combination 3 ((B1b) polyols having a number average molecular weight of less than 1200 (excluding polyester polyols) and (B2) polyester polyols having a number average molecular weight of 1200 or more), the content of (B-1) polyester polyol in (B) hydroxyl group-containing compound is the content of (B2) polyester polyols having a number average molecular weight of 1200 or more, and is 30% by mass or more and less than 100% by mass relative to 100% by mass of (B) hydroxyl group-containing compound.

The (B) hydroxyl group-containing compound preferably includes combination 1 ((B1a) polyester polyol having a number average molecular weight of less than 1200, and (B2) polyester polyol having a number average molecular weight of 1200 or more), and combination 2 ((B1a) polyester polyol having a number average molecular weight of less than 1200, and (B3) polyol having a number average molecular weight of 1200 or more (excluding polyester polyol)), and more preferably includes combination 2 ((B1a) polyester polyol having a number average molecular weight of less than 1200, and (B3) polyol having a number average molecular weight of 1200 or more (excluding polyester polyol)).

1-3. (C) Polymerization catalyst The (C) polymerization catalyst is at least one selected from the group consisting of (C1) organometallic catalysts, in which the metal is an element of Group 4 of the periodic table, and (C2) reactive amine catalysts.

(C1) Organometallic catalysts, the metal being an element of group 4 of the periodic table As used herein, the term "organometallic catalyst" refers to a catalyst containing an organic radical and at least one metal, where the term "organic radical" refers to a radical having at least one carbon atom.
The metal of the organometallic catalyst is an element belonging to Group 4 of the periodic table.
The elements belonging to Group 4 of the periodic table include titanium, zirconium, hafnium, etc., with zirconium and titanium being preferred.
As the organometallic catalyst (C1), in which the metal is an element of Group 4 of the periodic table, any zirconium compound or titanium compound that is usually used as a catalyst in a urethanization reaction can be used.

Examples of organometallic catalysts in which the metal is zirconium (hereinafter also referred to as "organozirconium catalysts") include zirconium alkoxide compounds, acylate compounds, and chelate compounds.
Examples of zirconium alkoxide compounds (hereinafter also referred to as "zirconium alkoxides") include zirconium tetra-normal-propoxide and zirconium tetra-normal-butoxide.
Examples of zirconium chelate compounds (hereinafter also referred to as "zirconium chelate complexes") include zirconium tetraacetylacetonate, zirconium dibutoxybis(ethylacetoacetate), zirconium tributoxymonoacetylacetonate, and zirconium monobutoxyacetylacetonate bis(ethylacetylacetonate).

Examples of organometallic catalysts in which the metal is titanium (hereinafter, also referred to as "organotitanium catalysts") include titanium alkoxide compounds and chelate compounds.
Examples of titanium alkoxide compounds (hereinafter also referred to as "titanium alkoxides") include titanium tetraisopropoxide, titanium tetra-n-butoxide, titanium tetra-2-ethylhexoxide, titanium butoxide dimer, and the like.
Examples of titanium chelate compounds (hereinafter also referred to as "titanium chelate complexes") include titanium tetraacetylacetonate, titanium diisopropoxybis(acetylacetonate), titanium dioctyloxybis(octylene bricolate), titanium diisopropoxybis(ethylacetoacetate), titanium diisopropoxybis(triethanolaminate), titanium lactate ammonium salt, and titanium lactate.

Among the organometallic catalysts, organozirconium catalysts are preferred, and zirconium chelate complexes are more preferred. Furthermore, among the zirconium chelate complexes, zirconium tetraacetylacetonate is preferred.

(C2) Reactive amine catalyst The (C2) reactive amine catalyst is an amine catalyst having a functional group in the molecule that reacts with an isocyanate compound. The reactive amine catalyst functions as a catalyst during the production of a polyurethane resin, and at the same time, reacts and is fixed to the resin skeleton after curing.
An example of the functional group that reacts with an isocyanate compound is a hydroxyl group.
The reactive amine catalyst is preferably an amine compound containing at least one hydroxyl group in the molecule. Examples of the amine compound containing at least one hydroxyl group in the molecule include 2-dimethylaminoethanol, 6-dimethylamino-1-hexanol, 2-[2-(dimethylamino)ethoxy]ethanol, and 1,4-azabicyclo[2.2.2]octane-2-methanol, and 1,4-azabicyclo[2.2.2]octane-2-methanol is preferred.

The content of the (C) polymerization catalyst may be within a range that does not impair the effect. For example, it is preferably 0.00001 to 10 mass%, more preferably 0.0001 to 5 mass%, and even more preferably 0.001 to 2 mass%, relative to 100 mass% of the polyurethane resin composition.

The polymerization catalyst (C) may be used alone or in combination of two or more.
The (C) polymerization catalyst can be (i) only (C1) an organometallic catalyst in which the metal is an element of Group 4 of the periodic table, (ii) only (C2) a reactive amine catalyst, or (iii) both (C1) an organometallic catalyst in which the metal is an element of Group 4 of the periodic table and (C2) a reactive amine catalyst.
In the case of (i) above, it is preferable to use an organic zirconium catalyst, and it is more preferable to use a zirconium chelate complex.
In the case of (ii) above, it is preferable to use 1,4-azabicyclo[2.2.2]octane-2-methanol.
In the case of (iii) above, it is preferable to use an organic zirconium catalyst in combination with a reactive amine catalyst.

If necessary, the present invention can incorporate known polymerization catalysts other than (C1) an organometallic catalyst in which the metal is a Group 4 element of the periodic table, and (C2) a reactive amine catalyst.

(C1) Known polymerization catalysts other than organometallic catalysts in which the metal is an element of Group 4 of the periodic table, and (C2) reactive amine catalysts include organometallic catalysts in which the metal is an element other than an element of Group 4 of the periodic table; non-reactive amine catalysts, etc.

Examples of organometallic catalysts in which the metal is an element other than Group 4 elements of the periodic table include organotin catalysts, organolead catalysts, and organobismuth catalysts.
Examples of the organotin catalyst include dioctyltin dilaurate, dibutyltin diacetate, dibutyltin dilaurate, and dioctyltin diacetate.
Examples of the organic lead catalyst include lead octoate, lead octenate, and lead naphthenate.
Examples of the organic bismuth catalyst include bismuth octoate and bismuth neodecanoate.

A non-reactive amine catalyst is an amine catalyst that remains in the product after functioning as a catalyst. Catalysts generally referred to as "amine catalysts" fall into the category of non-reactive amine catalysts.
Examples of non-reactive amine catalysts include diethylenetriamine, triethylamine, N,N-dimethylcyclohexylamine, N,N,N',N'-tetramethylethylenediamine, N,N,N',N",N"-pentamethyldiethylenetriamine, trimethylenediamine, dimethylaminoethanol, and bis(2-dimethylaminoethyl)ether.

When (C1) an organometallic catalyst in which the metal is a Group 4 element of the periodic table and (C2) a known polymerization catalyst other than a reactive amine catalyst are contained, the content may be within a range that does not impair workability, and is, for example, preferably 0.00001 to 10 mass%, more preferably 0.0001 to 5 mass%, and even more preferably 0.001 to 2 mass%, relative to 100 mass% of the polyurethane resin composition.

The above-mentioned (C1) organometallic catalyst, in which the metal is an element of Group 4 of the periodic table, and the known polymerization catalyst other than the (C2) reactive amine catalyst may be used alone or in combination of two or more.
From the viewpoint of safety for the human body and the environment, it is preferable not to use an organotin catalyst as the polymerization catalyst (C).
From the viewpoint of electrical insulation, it is preferable not to use a non-reactive amine catalyst.

1-4. (D) Plasticizer The polyurethane resin composition of the present invention may further contain (D) a plasticizer, if necessary.

The plasticizer (D) used in the present invention is not particularly limited, and examples thereof include ester group-containing plasticizers, phosphorus-based plasticizers, and hydrocarbon-based plasticizers.

Examples of ester group-containing plasticizers include phthalate ester plasticizers such as dioctyl phthalate, diisononyl phthalate (diisononyl phthalate), and diundecyl phthalate; adipate ester plasticizers such as dioctyl adipate, diisononyl adipate, and diisodecyl adipate; castor oil ester plasticizers such as methyl acetyl ricinoleate, butyl acetyl ricinoleate, acetylated ricinoleic acid triglyceride, and acetylated polyricinoleic acid triglyceride; trimellitic acid esters such as trioctyl trimellitate and triisononyl trimellitate; and pyromellitic acid ester plasticizers such as tetraoctyl pyromellitate and tetraisononyl pyromellitate.

Examples of phosphorus-based plasticizers include triphenyl phosphate (TPP), tricresyl phosphate (TCP), trixylenyl phosphate (TXP), cresyl diphenyl phosphate (CDP), etc.

Examples of hydrocarbon plasticizers include olefinic hydrocarbons such as ethylene and α-olefin co-oligomers, poly-α-olefins, and hydrogenated poly-α-olefins, paraffinic hydrocarbons, naphthenic hydrocarbons, and mixed paraphene-naphthenic hydrocarbons.

Among these, ester group-containing plasticizers and phosphorus-based plasticizers are preferred, and phosphorus-based plasticizers are more preferred.

When the polyurethane resin composition of the present invention contains a plasticizer (D), the content of the plasticizer (D) is preferably 0.01 to 50 mass%, more preferably 0.1 to 30 mass%, and particularly preferably 1 to 25 mass%, relative to 100 mass% of the polyurethane resin composition.

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

1-5. (E) Inorganic Filler (E) An inorganic filler can be added to the polyurethane resin composition of the present invention as long as the effects of the present invention are not adversely affected.

The inorganic filler (E) used in the present invention is not particularly limited, and examples thereof include metal hydroxides, metal oxides, metal nitrides, zeolites, etc. Furthermore, the surface of the metal oxides, etc. may be treated. Examples of methods for treating the surface of the metal oxides, etc. include oxidation treatment and treatment with a surface treatment agent such as a silane coupling agent.

Examples of metal hydroxides include aluminum hydroxide and magnesium hydroxide. Here, aluminum hydroxide and magnesium hydroxide also act as flame retardants.

Examples of metal oxides include aluminum oxide (alumina), magnesium oxide, silicon dioxide (silica, etc.), titanium oxide, etc.

Examples of metal nitrides include boron nitride, aluminum nitride, and silicon nitride.

There are no particular limitations on the zeolite, and any zeolite used in known polyurethane resin compositions can be used.

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

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

The alkali metal or alkaline earth metal in the zeolite is not particularly limited, and examples include potassium, sodium, calcium, lithium, etc. Among these, potassium is preferred.

A preferred inorganic filler is zeolite.

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

When the polyurethane resin composition of the present invention contains an inorganic filler (D), the content of the inorganic filler (D) is usually preferably 1 to 85% by mass, more preferably 5 to 70% by mass, and particularly preferably 20 to 60% by mass, based on 100% by mass of the polyurethane resin composition.

1-6. Other Components The polyurethane resin composition of the present invention may further contain various additives, such as an antifoaming agent, a flame retardant, a crosslinking agent (chain extender), an antioxidant, a tackifier, a curing accelerator, a colorant, a filler, a pigment, a bulking agent, an ultraviolet absorber, a moisture absorber, an antifungal agent, and a silane coupling agent, as necessary.

There are no particular limitations on the antifoaming agent, but examples include silicones (oil type, compound type, self-emulsifying type, emulsion type, etc.), alcohols, etc.

The preferred silicone-based defoaming agent is a modified silicone-based defoaming agent (especially one in which polysiloxane is modified with a hydrophilic group, with the lipophilic group being polysiloxane).

The above defoaming agents can be used alone or in combination of two or more.

When an antifoaming agent is included, its content is not particularly limited, but is preferably 0.001 to 10 mass% and more preferably 0.005 to 5 mass% relative to 100 mass% of the polyurethane resin composition.

Examples of the flame retardant include inorganic flame retardants, bromine-based flame retardants, and chlorine-based flame retardants.
As the inorganic flame retardant, in addition to aluminum hydroxide, magnesium hydroxide, alumina, magnesium oxide, and silica described above as the inorganic filler, for example, antimony trioxide, antimony pentoxide, ammonium borate, etc. can be used.
Examples of bromine-based flame retardants include hexabromobenzene, decabromodiphenyl oxide (DBDPO), tetrabromobisphenol A (TBBA), and ethylenebis(pentabromophenyl).
Examples of chlorine-based flame retardants include chlorinated paraffin, perchlorocyclopentadecanone, and chlorendic acid.

When the polyurethane resin composition of the present invention contains a flame retardant, the content of the flame retardant is usually preferably 5 to 85% by mass, more preferably 10 to 70% by mass, and particularly preferably 20 to 60% by mass, relative to 100% by mass of the polyurethane resin composition.

The crosslinking agent (chain extender) is not particularly limited, and examples thereof include aromatic alcohol crosslinking agents such as N,N-bis(2-hydroxypropyl)aniline, hydroquinone-bis(β-hydroxyethyl)ether, and resorcinol-bis(β-hydroxyethyl)ether;
Aliphatic alcohol-based crosslinking agents such as ethylene glycol, 1,3-butanediol (1,3-butylene glycol), 1,4-butanediol, octanediol, trimethylolpropane, and triisopropanolamine;
Aromatic amine-based crosslinking agents such as phenylenediamine, tolylenediamine, diphenyldiamine, 4,4'-diaminodiphenylmethane, 3,3'-dichloro-4,4'-diaminodiphenylmethane, 1,2-bis(2-aminophenylthio)ethane, and trimethylene glycol-p-aminobenzoate;
Examples of the crosslinking agents include aliphatic amine-based crosslinking agents such as ethylenediamine, propylenediamine, hexamethylenediamine, and diethylenetriamine.

Among these, aromatic alcohol-based crosslinking agents and aliphatic alcohol-based crosslinking agents are preferred, and aliphatic alcohol-based crosslinking agents are more preferred.

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

When the polyurethane resin composition of the present invention contains a crosslinking agent, the content of the crosslinking agent is not particularly limited, and is, for example, usually 0.01 to 30% by mass, preferably 1 to 20% by mass, and more preferably 2 to 15% by mass, relative to 100% by mass of the polyurethane resin composition.

The above crosslinking agents can be used alone or in combination of two or more.
As the crosslinking agent, among aliphatic alcohol-based crosslinking agents, short-chain diols having a number average molecular weight of 500 or less (eg, ethylene glycol, 1,3-butanediol, 1,4-butanediol, octanediol, etc.) can be preferably used.

The content of these components may be appropriately determined based on the usual amounts added and the ranges of their identification, depending on the intended use, so as not to impair the desired properties of the polyurethane resin composition.

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

Examples of such a production method include a method including a step (step 1) of preparing (A) a composition (first component) containing an isocyanate compound, a step (step 2) of preparing (B) a composition (second component) containing a hydroxyl group-containing compound, and a step (step 3) of mixing the second component with the first component to obtain a polyurethane resin composition.

As long as the first component (agent I) contains (A) an isocyanate compound and the second component (agent II) contains (B) a hydroxyl group-containing compound, the other components may be contained in either the second component or the first component.

Here, the first component (agent I) can contain other components in addition to the isocyanate compound (A).

The second component (agent II) may contain other components in addition to the hydroxyl group-containing compound (B).

For example, when the first component (agent I) contains a hydroxyl group-containing compound in addition to the isocyanate compound (A), the first component (agent I) may be a urethane prepolymer having an isocyanate group (NCO) at the end.

Similarly, when the second component (agent II) contains an isocyanate compound (A) in addition to the hydroxyl group-containing compound (B), the second component (agent II) may be a urethane prepolymer having a hydroxyl group (OH) at the end.

Specifically, the (X) urethane prepolymer is obtained by reacting a component containing (A) an isocyanate compound and (B) a hydroxyl group-containing compound. The (X) urethane prepolymer includes not only a urethane prepolymer obtained by reacting a material consisting of the (A) and (B) components, but also a urethane prepolymer obtained by reacting the (A) and (B) components with optional components, etc., and may also contain the other components described above.

More specifically, the polyurethane resin composition of the present invention may have a structure in which the first component contains an isocyanate compound (A), a polymerization catalyst (C), and a plasticizer (D), and the second component contains a compound (B) and an inorganic filler (E);
A structure in which the first component contains (A) an isocyanate compound, and the second component contains (B) a hydroxyl group-containing compound, (C) a polymerization catalyst, (D) a plasticizer, and (E) an inorganic filler;
The first component may contain (A) an isocyanate compound and (C) a polymerization catalyst, and the second component may contain (B) a hydroxyl group-containing compound, (D) a plasticizer, and (E) an inorganic filler.

The first component contains (A) an isocyanate compound and (E) an inorganic filler, and the second component contains (B) a hydroxyl group-containing compound and (C) a polymerization catalyst;
A structure in which the first component contains (A) an isocyanate compound, (C) a polymerization catalyst, and (D) a plasticizer, and the second component contains (B) a hydroxyl group-containing compound, (D) a plasticizer, and (E) an inorganic filler;
A structure in which the first component contains (A) an isocyanate compound and (D) a plasticizer, and the second component contains (B) a hydroxyl group-containing compound, (C) a polymerization catalyst, (D) the plasticizer, (E) an inorganic filler, and (F) an antifoaming agent;
The first component may contain (A) an isocyanate compound, (C) a polymerization catalyst, and (D) a plasticizer, and the second component may contain (B) a hydroxyl group-containing compound, (D) a plasticizer, (E) an inorganic filler, and (F) an antifoaming agent.

When producing a polyurethane resin composition, the first component (agent I) is usually used in an amount of 1 to 1,000 parts by mass, preferably 3 to 100 parts by mass, and more preferably 5 to 25 parts by mass, per 100 parts by mass of the second component (agent II).
The reason for blending other components with the first component is to lower the viscosity of the polyisocyanate compound and to match the ratio (blending ratio) of the first component and the second component. Therefore, the first component can be used without blending other components. If necessary, the first component or the second component may be diluted with an organic solvent (e.g., toluene, methyl ethyl ketone, butyl acetate, etc.) or water before mixing, or the first component and the second component may be mixed and then diluted with the organic solvent or water. Diluting with an organic solvent or water reduces the viscosity of each agent, improving workability.

In the polyurethane resin composition, (A) the isocyanate compound and (B) the hydroxyl group-containing compound may react partially or completely to form a polyurethane resin. That is, the polyurethane resin composition may be in a liquid state before curing, or may be cured. The polyurethane resin composition may be cured over time by mixing the first and second components, whereby (A) the isocyanate compound and (B) the hydroxyl group-containing compound react to form a polyurethane resin, but it may also 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.

The glass transition temperature of the obtained polyurethane resin composition, calculated from the maximum peak point of the loss modulus (E″: 10 Hz) measured by DMA (dynamic viscoelasticity measurement), is usually 20° C. or lower, preferably 0° C. or lower, and more preferably lower than −20° C.
When the glass transition temperature of the polyurethane resin composition is lower than −20° C., the glass transition temperature is sufficiently low, so that a sudden change in elastic modulus due to phase transition can be suppressed and stress on electronic components due to thermal cycles can be alleviated, and therefore the polyurethane resin composition can be said to have excellent heat cycle properties.

3. Applications The polyurethane resin composition of the present invention has excellent moisture resistance and is capable of suppressing deterioration of electrical insulation properties, and therefore can be suitably used as an adhesive for flexible substrates and multilayer substrates, a surface coating agent, etc.

The polyurethane resin composition of the present invention will be specifically described below with reference to examples and comparative examples. However, the examples are merely illustrative, and the present invention is not limited to the examples.

The raw materials used in the examples and comparative examples are listed below.

<(A) Isocyanate Compound>
A1: MTL
Product name: Millionate MTL (registered trademark) (carbodiimide-modified MDI), manufactured by Tosoh Corporation, molecular weight 250, specific gravity 1.22
A2: M5S
Product name: Luplanate M5S (Polymeric MDI), manufactured by BASF INOAC Polyurethanes, specific gravity 1.22
A3: TSA-100
Product name: Duranate (registered trademark) TSA-100 (HDI isocyanurate modified product), manufactured by Asahi Kasei Corporation, molecular weight 514, specific gravity 1.12

<(B) Hydroxyl Group-Containing Compound>
(B-1) Polyester polyol b1: H-30 (castor oil-based polyol)
Product name: URIC H-30, manufactured by Ito Oil Mills Co., Ltd. (castor oil-based polyol for polyurethanes), number average molecular weight: 933, average functionality: 2.7, hydroxyl value: 161 mg KOH/g (JIS K 1557)
b2: Y-403 (castor oil polyol)
Product name: URIC Y-403, manufactured by Ito Oil Mills Co., Ltd. (castor oil-based polyol for polyurethanes), number average molecular weight: 700, average functionality: 2, hydroxyl value: 160 mg KOH/g (JIS K 1557)
b3: P-2050 (condensation type polyester polyol)
Product name: Kuraray Polyol P-2050, manufactured by Kuraray Co., Ltd., number average molecular weight: 2000, average functionality: 2.0, hydroxyl value: 56 mg KOH/g (JIS K 1557)
(B-2) Polyolefin polyol b4: R-45HT (polybutadiene polyol)
Product name: Poly bd (registered trademark) R-45HT, manufactured by Idemitsu Kosan Co., Ltd., number average molecular weight: 2800, average number of functional groups: 2.2, hydroxyl value: 45 mg KOH/g (JIS K 1557)
(B-3) Polyether polyol b5: PP-2000
Product name: Sannix PP-2000, manufactured by Sanyo Chemical Industries, Ltd., number average molecular weight: 2000, average number of functional groups: 2.0, hydroxyl value: 56 mg KOH/g (JIS K 1557)

<(C) Polymerization Catalyst>
(C1) An organometallic catalyst, the metal of which is an element of Group 4 of the periodic table; c1: organozirconium catalyst (1): zirconium tetraacetylacetonate solution;
Product name: Orgatix (registered trademark) ZC-700, manufactured by Matsumoto Fine Chemical Co., Ltd., active ingredient concentration 20% by mass, metal element content 3.8% by mass
Organic zirconium catalyst (2): zirconium dibutoxybis(ethylacetoacetonate) solution,
Product name: Orgatix (registered trademark) ZC-580, manufactured by Matsumoto Fine Chemical Co., Ltd., active ingredient concentration 70% by mass, metal element content 13.1% by mass
c2: organic titanium catalyst: titanium tetra-2-ethylhexoxide,
Product name: Orgatix (registered trademark) TA-30, manufactured by Matsumoto Fine Chemical Co., Ltd., active ingredient concentration over 99% by mass, metal element content 8.5% by mass
(C2) Reactive amine catalyst c3: reactive amine catalyst: 1,4-diazabicyclo[2.2.2]octane 2-methanol solution,
Product name: RZETA (registered trademark)-HD, a polymerization catalyst other than (C1) and (C2) manufactured by Tosoh Corporation,
c4: non-reactive amine catalyst: 1,4-diazabicyclo[2.2.2]octane solution,
Product name: DABCO (registered trademark) 33LV, manufactured by Air Products and Chemicals, active ingredient concentration 33% by mass
c5: organotin catalyst: dioctyltin dilaurate,
Product name: Neostan (registered trademark) U-810, manufactured by Nitto Kasei Co., Ltd.

<(D) Plasticizer>
d1: tricresyl phosphate (TCP)
Product name: TCP, manufactured by Daihachi Chemical Industry Co., Ltd., molecular weight: 368, specific gravity: 1.17
d2: Phthalate ester (DINP)
Product name: DINP, manufactured by JPlus Corporation (diisononyl phthalate), molecular weight: 419, specific gravity: 0.97

<(E) Inorganic filler>
e1: Zeolite: Molecular sieves, product name: Molecular sieves 5A, manufactured by Showa Denko Materials Co., Ltd.

Preparation of Polyurethane Resin Compositions <Examples 1 to 19, Comparative Examples 1 to 11, and Reference Example 1>
Various polyurethane resin compositions were prepared by the following procedure using the components in the compositions and amounts (parts by mass) shown in Tables 1 and 2.

(B) A hydroxyl group-containing compound, (C) a polymerization catalyst, (D) a plasticizer, and (E) an inorganic filler shown in Tables 1 and 2 were mixed for 1 minute at 2000 rpm using a centrifugal mixer (Thinky Mixer, manufactured by Thinky Corporation).
The isocyanate compound (A) shown in Tables 1 and 2 was added to the above mixed components, and mixed for 1 minute at 2000 rpm using a planetary centrifugal mixer (Thinky Mixer, manufactured by Thinky Corporation). The resulting mixture was degassed to obtain polyurethane resin compositions of Examples 1 to 19, Comparative Examples 1 to 11, and Reference Example 1.

The following tests were carried out using each of the obtained polyurethane resin compositions.
<Preparation of test pieces>
The prepared polyurethane resin composition was poured into a molding die of 100×100×3 mm or a molding die of 30 mm inner diameter and 10 mm height. The polyurethane resin composition was then heated at 60° C. for 16 hours, and then allowed to stand at room temperature for one day to harden, to obtain test piece A (100×100×3 mm), test piece B (diameter 30 mm and height 10 mm), and test piece C (test piece A cut to 10×80×3 mm).

The following measurements and tests were carried out using the polyurethane resin compositions of Examples 1 to 19, Comparative Examples 1 to 11, and Reference Example 1, or test pieces A to C, prepared as described above.

<Electrical insulation: volume resistivity>
The volume resistivity of the test piece A was measured using a resistance meter (DSM-8104, manufactured by HIOKI Corporation). Based on the measurement results, the electrical insulation was evaluated according to the following evaluation criteria. The measured volume resistivity values (Ω·m) and the evaluation results are shown in Tables 1 and 2.

Electrical insulation evaluation criteria: 1E+12 or more: A
・1E+10 or more and less than 1E+12: B
Less than 1E+10: C

<High temperature and humidity test>
The hardness (Type A) of test piece B (inner diameter 30 mm, height 10 mm) at a temperature of 23° C. was measured in accordance with JIS K 6253 using a hardness meter (Asker rubber hardness meter: Type A, manufactured by Kobunshi Keiki Co., Ltd.).
A moisture resistance test was carried out using a PCT (pressure cooker) testing machine (conditions: 121°C, 100% RH). After cooling to room temperature (23°C), the hardness of test piece B was measured, and the time until the initial hardness A was reduced by half (1) and by one-quarter (2) was measured.
Here, the higher the initial hardness and crosslink density (average number of functional groups of polyol) of the resin, the more advantageous the results of the high temperature and high humidity test, so the molecular structure of the polyurethane resin composition has a large influence. Therefore, it is difficult to accurately compare the evaluation of the deterioration reaction caused by the catalyst. Therefore, (3) the evaluation was performed using a correction value obtained by multiplying the correction coefficient of the molecular crosslink strength by the measurement time.
(3) The correction coefficient for molecular crosslink strength was calculated from the following formula, with the median being "50" for hardness and "2" for crosslink density.

Evaluation criteria for high temperature and high humidity test: The result of (1) x (3) is 21 or more and the result of (2) x (3) is 32 or more: A
The result of (1) x (3) is 10 or more and less than 21, and the result of (2) x (4) is 15 or more and less than 32: B
The result of (1) x (3) is less than 10, or the result of (2) x (4) is less than 15: C

<Workability>
The obtained polyurethane resin composition was adjusted to 23° C., and the viscosity was measured 2 minutes after the start of mixing using a Brookfield BH viscometer. The viscosity at the start of the measurement was defined as the initial viscosity, and the time until the viscosity reached 4 Pa·s was measured.

Workability evaluation standard Time to reach 4 Pa·s (s)
・200 to less than 1000: A
・1000 to less than 2000: B
- Not applicable to evaluation criteria "A" or "B" (less than 200 or 2000 or more): C

<Glass transition temperature>
The glass transition temperature (° C.) of the test piece C was measured using a dynamic viscoelasticity measuring device: DMA (manufactured by SII Nano Technology: DMS6100). The glass transition temperature was calculated from the peak temperature of the loss modulus (E″).

Glass transition temperature evaluation criteria: Less than -20°C: A
-20℃ or higher and below 0℃: B
0℃ or higher: C

The total score was calculated by adding up the number of "A" ratings x 5 points + the number of "B" ratings x 3 points + the number of "C" ratings x 1 point, and the overall evaluation was based on the following evaluation criteria.

Overall evaluation "Overall evaluation score" is 18 or more and all evaluation items are "B" or higher: A
"Overall evaluation score" is between 15 and 18, and all evaluation items are "B" or higher: B
"Overall evaluation score" is less than 15, or there is a "C" in any of the evaluation items of "electrical insulation, high temperature and high humidity test, workability, glass transition temperature": C
The results are shown in Tables 1 and 2.

<Judgment Results>
The polyurethane resin compositions of Examples 1 to 19 were rated B or higher in all of the electrical insulation properties, high temperature and humidity test, workability, and glass transition temperature, and the overall rating was A or B.

The cured polyurethane resin obtained from the polyurethane resin composition of the present invention has excellent moisture resistance and is inhibited from decreasing in electrical insulation, and therefore can be used for flexible substrates, adhesives for multilayer substrates, surface coating agents, sealants, coverlays, bonding sheets, copper foils, laminates, dry films, electronic component materials, etc.

Claims (9)

A sealing material comprising a polyurethane resin composition containing (A) an isocyanate compound, (B) a hydroxyl group-containing compound, and (C) a polymerization catalyst,
The (B) hydroxyl group-containing compound has an average hydroxyl value of 20 to 150 mgKOH/g and an average functionality of 1.8 to 3.5,
The (B) hydroxyl group-containing compound includes a polyester polyol,
The polyester polyol is contained in an amount of 30% by mass to 100% by mass based on 100% by mass of the hydroxyl group-containing compound (B), and
The (C) polymerization catalyst is at least one selected from the group consisting of (C1) organometallic catalysts, in which the metal is an element of Group 4 of the periodic table, and (C2) reactive amine catalysts, and does not contain a non-reactive amine catalyst. An electric/electronic component resin-sealed with the sealing material according to claim 1. A polyurethane resin composition for electrical insulation comprising (A) an isocyanate compound, (B) a hydroxyl group-containing compound, and (C) a polymerization catalyst,
The (A) isocyanate compound includes an aromatic polyisocyanate compound, a modified product thereof, or a polynuclear product thereof,
The (B) hydroxyl group-containing compound has an average hydroxyl value of 20 to 150 mgKOH/g and an average functionality of 1.8 to 3.5,
The (B) hydroxyl group-containing compound is
(B1) a polyol having a number average molecular weight of less than 1,200;
(B2) a polyester polyol having a number average molecular weight of 1,200 or more, or
(B3) a polyol having a number average molecular weight of 1,200 or more (excluding polyester polyols),
the total amount of the polyester polyol contained in the (B1) polyol having a number average molecular weight of less than 1,200 and the (B2) polyester polyol having a number average molecular weight of 1,200 or more is 30% by mass to 100% by mass relative to 100% by mass of the (B) hydroxyl group-containing compound ,
the (C) polymerization catalyst is at least one selected from the group consisting of (C1) organometallic catalysts, in which the metal is an element of Group 4 of the periodic table, and (C2) reactive amine catalysts;
Does not contain a non-reactive amine catalyst; and
The volume resistivity of the polyurethane resin composition for electrical insulation after curing is 1E+10 Ω·m or more.
An electrically insulating polyurethane resin composition. The polyurethane resin composition according to claim 3 , wherein the modified product is an isocyanurate product, a carbodiimide product, an adduct product, a biuret product, or an allophanate product . 4. The electrically insulating polyurethane resin composition according to claim 3, wherein the organometallic catalyst (C1), in which the metal is an element of Group 4 of the periodic table, is at least one selected from the group consisting of zirconium alkoxides, zirconium chelate complexes, titanium alkoxides, and titanium chelate complexes. The electrically insulating polyurethane resin composition according to claim 3 , further comprising (D) a plasticizer. 4. The electrically insulating polyurethane resin composition according to claim 3 , wherein the (B3) polyol (excluding polyester polyol) having a number average molecular weight of 1,200 or more contains a polybutadiene polyol. 4. The electrically insulating polyurethane resin composition according to claim 3 , wherein the polymerization catalyst (C) is a zirconium chelate complex. The (B) hydroxyl group-containing compound is
(B1a) a polyester polyol having a number average molecular weight of less than 1,200, and
(B3) A polyol having a number average molecular weight of 1,200 or more (excluding polyester polyols),
4. The electrically insulating polyurethane resin composition according to claim 3, wherein the glass transition temperature of the electrically insulating polyurethane resin composition after curing is less than 0°C.