Polyurethane resin composition

Abstract

To provide a polyurethane resin composition which has good workability in a coating step, and is excellent in electric insulation property of a coating film after coating.SOLUTION: A polyurethane resin composition contains a crystalline urethane prepolymer (A) and an amorphous urethane prepolymer (B), wherein a melting point of the polyurethane resin composition is 70°C or lower, and a solidification point of the polyurethane resin composition is 0°C or higher and 40°C or lower.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present disclosure relates to a polyurethane resin composition, etc. [Background technology]

[0002] An electronic circuit mounting board (hereinafter sometimes referred to as a "mounting board") is a circuit board on which various electronic components such as capacitors and IC (integrated circuit) chips are mounted on its surface. Currently, electronic circuit mounting boards are important electric and electronic components used in a variety of products such as personal computers, electrical appliances, and automobile computers. The electronic circuit mounting boards mounted on the above-mentioned products are required to have durability such as water resistance, moisture resistance, vibration resistance, shock resistance, dust resistance, etc. By improving these durability properties, malfunctions of various products can be prevented and their life spans can be extended.

[0003] In the past, in order to improve the durability of electronic circuit boards, they have been protected using potting agents (also called casting agents or sealing materials) or conformal coating agents (also called insulating protective coatings).

[0004] For example, as shown in FIG. 1, a potted electronic circuit mounting board is integrated with the case material by pouring a potting agent into the case material containing the board and then hardening it. The case material and the mounting board are integrated with the potting agent, thereby improving the durability (for example, vibration resistance, waterproofing, etc.) of the electronic circuit mounting board (and the electric and electronic components). However, this potted mounting board requires a large amount of potting agent, making it difficult to reduce the weight of the parts. In addition, when discarding the board, recycling is not possible unless the thick resin layer (potting agent) is removed and the mounting board and case material are separated. This means that the board is treated as industrial waste and cannot be recycled.

[0005] On the other hand, conformal coating agents have the advantages of being used in smaller amounts than potting agents and not requiring the casing material shown in Figure 1 above, as with potting agents. However, when an ultraviolet-curable coating agent is used as the conformal coating agent, there is a problem in that the ultraviolet light is blocked by the electronic components, resulting in non-irradiated areas, which in turn result in uncured portions. In addition, conformal coating agents with extremely low viscosity (for example, 100 mPa·s or less) are used, but because of the low viscosity and the long drying time, it is difficult to control the thickness to 100 μm or more, and uneven coating can occur near uneven mounted components. Therefore, conformal coating agents have the problem that uneven application occurs near the mounted components, and the coating agent does not harden properly, which limits the shapes and sizes of the mounted components to which they can be applied.

[0006] In addition, in recent years, there has been a need to reduce the carbon footprint (CF) during manufacturing and improve the ease of dismantling protective materials for electronic circuit boards in order to promote the use of sustainable materials. For this reason, the use of hot melt, which does not require a curing process, as a coating agent for mounting boards has been considered (for example, Patent Documents 1 and 2).

[0007] For example, Patent Document 1 describes a hot melt coating agent for electronic circuit mounting boards. The hot melt coating agent for electronic circuit mounting boards contains a thermoplastic resin and a liquid softener, has a melt viscosity (η1) of 20,000 mPa.s or less at 160°C, a melt viscosity (η2) of 10,000 mPa.s or less at 180°C, and a ratio (η1 / η2) of the melt viscosity (η1) at 160°C to the melt viscosity (η2) at 180°C of 1.0 to 5.0. However, in Patent Document 1, a high melting temperature (160°C or higher) is required to ensure workability (viscosity) and heat resistance (the upper limit temperature of the operating environment of the electronic mounting board), which increases the risk of thermal damage to the mounted components and the danger of working. In addition, the thickness of the coating must be 700 μm or more (more preferably 1500 μm or more), which makes the dismantling (recyclability) of the electronic component mounting board insufficient.

[0008] Patent Document 2 describes a one-component moisture-curing polyurethane coating agent. The one-component moisture-curing polyurethane coating agent is obtained by reacting (a) an organic polyisocyanate, (b) a polycarbonate diol having a number average molecular weight of 500 to 3000, (c) a polyester polyol having a number average molecular weight of 1000 to 5000, the constituent unit of which is a diol monomer having an alkylene group with 6 to 12 carbon atoms, and (d) a siloxane-modified polyol having a number average molecular weight of 1000 to 15000, so that the NCO / OH ratio of (a) / [(b)+(c)+(d)] is 1.8 to 2.3. However, the coating agent of Patent Document 2 has a high viscosity and cannot be applied in a thin film unless it is flattened with a glass rod, spatula, etc., and the application performance of the coating agent is insufficient. In addition, the coating film obtained with this coating agent has low electrical insulation. [Prior art documents] [Patent documents]

[0009] [Patent Document 1] JP 2020-050859 A [Patent Document 2] JP 2008-156501 A Summary of the Invention [Problem to be solved by the invention]

[0010] An object of the present disclosure is to provide a polyurethane resin composition which has good workability in a coating step and provides a coating film with excellent electrical insulation properties after application. [Means for solving the problem]

[0011] As a result of intensive research into solving the above problems, the present inventors have found that the above problems can be solved by providing a polyurethane resin composition that contains a crystalline urethane prepolymer (A) and an amorphous urethane prepolymer (B) and has a melting point of 70° C. or less and a freezing point of 0° C. or more and 40° C. or less. The present disclosure has been completed based on such findings.

[0012] That is, the present disclosure relates to the following polyurethane resin composition, etc. Section 1. A crystalline urethane prepolymer (A); An amorphous urethane prepolymer (B); A polyurethane resin composition comprising: The melting point of the polyurethane resin composition is 70° C. or less, and The polyurethane resin composition has a freezing point of 0°C or higher and 40°C or lower. Section 2. Item 2. The polyurethane resin composition according to Item 1, wherein the amorphous urethane prepolymer (B) is an amorphous urethane prepolymer having, in a chemical structure, at least one bond selected from the group consisting of an unsaturated bond, an ether bond, and an ester bond. Section 3. The amorphous urethane prepolymer (B) is a mixture of at least one hydroxyl group-containing compound (G) selected from the group consisting of polyolefin polyols, polyether polyols, and polyester polyols, Item 3. The polyurethane resin composition according to item 1 or 2, wherein the polyurethane resin composition is a compound obtained by reacting with an isocyanate compound (D). Section 4. The amorphous urethane prepolymer (B) is a mixture of at least one hydroxyl group-containing compound (G) selected from the group consisting of polybutadiene polyols and castor oil polyols, 4. The polyurethane resin composition according to any one of items 1 to 3, which is a compound obtained by reacting with an isocyanate compound (D). Section 5. The crystalline urethane prepolymer (A) comprises a crystalline polyol (C) obtained by reacting an aliphatic dicarboxylic acid (E) with an aliphatic diol (F1) and / or a cyclic ether (F2); 5. The polyurethane resin composition according to any one of items 1 to 4, which is a compound obtained by reacting with an isocyanate compound (D). Section 6. Item 6. The polyurethane resin composition according to item 5, wherein the crystalline polyol (C) has a melting point of 70° C. or lower. Section 7. Item 5. The polyurethane resin composition according to item 3 or 4, wherein the hydroxyl group-containing compound (G) has a freezing point of 0° C. or lower. Section 8. 8. The polyurethane resin composition according to any one of items 1 to 7, further comprising a catalyst. Section 9. Volume resistivity is 5×10 10 9. The polyurethane resin composition according to any one of items 1 to 8, having a modulus of elasticity of Ω·m or more. Section 10. 10. The polyurethane resin composition according to any one of items 1 to 9, having a melt viscosity at 120° C. of 100 mPa·s or more and 5000 mPa·s or less. Section 11. 11. The polyurethane resin composition according to any one of items 1 to 10, which is a moisture-curable polyurethane resin composition. Section 12. Item 12. A conformal coating agent comprising the polyurethane resin composition according to any one of items 1 to 11. Section 13. Item 12. A hot melt coating agent for an electronic circuit mounting board, comprising the polyurethane resin composition according to any one of items 1 to 11. Section 14. 12. A coating film obtained from the polyurethane resin composition according to any one of items 1 to 11. Section 15. The amount of the coating film is 1 mg / cm 2 ~100mg / cm2 Item 15. The coating film according to item 14, wherein the coating film has a thickness of 10 μm to 1000 μm. Section 16. Item 16. An electronic circuit mounting board comprising a printed circuit board as a carrier layer in addition to the coating film according to item 14 or 15. Section 17. Item 1. An electric / electronic part coated with the polyurethane resin composition according to item 1.

[0013] Section 1-1. A crystalline urethane prepolymer (A); An amorphous urethane prepolymer (B); A polyurethane resin composition comprising: The polyurethane resin composition has a melting point of 70°C or lower and a freezing point of 0°C or higher and 40°C or lower. Section 2-1. The crystalline urethane prepolymer (A) comprises a crystalline polyol (C) obtained by reacting an aliphatic dicarboxylic acid (E) with an aliphatic diol (F1) and / or a cyclic ether (F2); The polyurethane resin composition according to item 1-1, which is a compound obtained by reacting with an isocyanate compound (D). Section 3-1. Item 2-1. The polyurethane resin composition according to Item 2-1, wherein the crystalline polyol (C) has a melting point of 70° C. or lower. Section 4-1. The amorphous urethane prepolymer (B) is a mixture of at least one hydroxyl group-containing compound (G) selected from the group consisting of polyether polyols, polyester polyols, polybutadiene polyols, and castor oil polyols, Item 1-1. The polyurethane resin composition according to Item 1-1, which is a compound obtained by reacting with an isocyanate compound (D). Section 5-1. Item 4-1. The polyurethane resin composition according to Item 4-1, wherein the hydroxyl group-containing compound (G) has a freezing point of 0° C. or lower. Section 6-1. Item 1-1. The polyurethane resin composition according to Item 1-1, wherein the amorphous urethane prepolymer (B) is an amorphous urethane prepolymer having an unsaturated bond in its chemical structure. Section 7-1. Volume resistivity is 5×10 10 Item 1-1. The polyurethane resin composition according to item 1-1, wherein the elastic modulus is Ω·m or more. Section 8-1. Item 1-1. The polyurethane resin composition according to item 1-1, having a melt viscosity at 120°C of 100 mPa·s or more and 5000 mPa·s or less. Section 9-1. Item 1-1. The polyurethane resin composition according to item 1-1, which is a moisture-curable type. Section 10. A conformal coating agent comprising the polyurethane resin composition according to any one of items 1-1 to 9-1. Section 11. A hot melt coating agent for an electronic circuit mounting board, comprising the polyurethane resin composition according to any one of items 1-1 to 9-1. Section 12. A coating film obtained from the polyurethane resin composition according to any one of items 1-1 to 9-1. Section 13-1. The amount of the coating film is 1 mg / cm 2 ~100mg / cm 2 or the coating film has a thickness of 10 μm to 1000 μm. Section 14-1. The electronic circuit mounting board according to item 13-1, further comprising a printed circuit board as a carrier layer. Section 15-1. Item 1-1. An electric / electronic part coated with the polyurethane resin composition according to item 1-1. Section 16-1. A cured product obtained from the polyurethane resin composition according to any one of items 1-1 to 9-1.

[0014] Among the inventions disclosed herein, those relating to products such as polyurethane resin compositions, conformal coating agents, hot melt coating agents for electronic circuit boards, coating films, electric and electronic components, and cured products, each of which is specified by a manufacturing process, are described using product-by-process claims because it is currently impossible or impractically difficult to specify what components are contained or what their structure is. Effect of the Invention

[0015] According to the present disclosure, it is possible to obtain a polyurethane resin composition which has good workability in the application step and provides a coating film with excellent electrical insulation properties after application. Furthermore, according to the present disclosure, the amount of polyurethane resin composition used is smaller than that of a potting agent, and a curing step using light or heat is not required, thereby reducing the takt time (the time required to manufacture one product) when coating an electronic circuit mounting board. Furthermore, compared to electronic circuit-mounted boards that use conventional potting agents or conformal coatings, the equipment for producing electronic circuit-mounted boards of the present disclosure consumes less energy during operation and allows for energy-saving production, thereby reducing the carbon footprint associated with the production of electronic circuit-mounted boards. Furthermore, the electronic circuit mounted board of the present disclosure has excellent dismantling (recyclability). [Brief description of the drawings]

[0016] [Figure 1] These are photographs (Figs. 1a and 1b) of an electronic component mounting board protected with a conventional potting agent. Fig. 1a is a photograph taken from above of the electronic component mounting board protected by the potting agent after the electronic component mounting board is placed in a case, a conventional potting agent is poured into it, and the potting agent is hardened. Fig. 1b is a photograph of Fig. 1a taken diagonally from above. [Diagram 2]2A and 2B are photographs of an electronic component mounting substrate coated with the polyurethane resin composition of the present disclosure. Fig. 2A is a photograph of the electronic component mounting substrate after the polyurethane resin composition of the present disclosure has been cured, taken from above. Fig. 2B is a photograph of Fig. 2A taken obliquely from above. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017] The polyurethane resin composition of the present disclosure will be described in detail below. In the present specification, the expression "contain" or "comprise" includes the concepts of "contain", "comprise", "consist essentially of" and "consist only of".

[0018] Polyurethane resin composition The polyurethane resin composition of the present disclosure contains a crystalline urethane prepolymer (A) and an amorphous urethane prepolymer (B), and the polyurethane resin composition has a melting point of 70°C or lower and a freezing point of 0°C or higher and 40°C or lower.

[0019] The polyurethane resin composition of the present disclosure has good workability in the coating process. In addition, when protecting (coating) an electronic component mounting board, the polyurethane resin composition is used in a smaller amount than a potting agent and does not require a curing process, so that the tact time (production time) when coating an electronic circuit mounting board and the energy consumption during production can be reduced.

[0020] The polyurethane resin composition of the present disclosure can be moisture-cured to produce a cured polyurethane resin having excellent electrical insulation properties, and can be easily dismantled (recyclable) and has a reduced carbon footprint. In this case, moisture curing refers to the self-crosslinking / curing of the polyurethane resin composition, such as when the isocyanate group is hydrolyzed in the presence of moisture to generate an amino group terminal, thereby forming a polyurea bond, or when the latent curing agent is decomposed by water to generate an amine or hydroxyl group, which reacts with the isocyanate group to form a polyurea / polyurethane bond.

[0021] Crystalline urethane prepolymer (A) The crystalline urethane prepolymer (A) is not particularly limited, and examples thereof include a compound obtained by reacting a crystalline polyol (C) with an isocyanate compound (D).

[0022] Crystalline polyol (C) The crystalline polyol (C) is not particularly limited as long as it is a crystalline solid at room temperature (25° C.). The melting point of the crystalline polyol (C) is preferably 70° C. or lower. The term "crystalline" means that the polyol has a crystalline structure at room temperature (25° C.).

[0023] The melting points of the crystalline urethane prepolymer (A) and the crystalline polyol (C) are measured by differential scanning calorimetry (DSC measurement). Specifically, they can be measured by raising the temperature at 20°C / min in an air stream together with a standard sample (alumina powder) and detecting the temperature (°C) showing the maximum endothermic peak.

[0024] Examples of the crystalline urethane prepolymer include a crystalline urethane prepolymer (A1) obtained by reacting a crystalline polyol (C1) obtained by reacting an aliphatic dicarboxylic acid (E) with an aliphatic diol (F1) and / or a cyclic ether (F2) with an isocyanate compound (D); and a crystalline urethane prepolymer (A2) obtained by reacting a crystalline hydrogenated polyolefin polyol (C2) with an isocyanate compound (D).

[0025] Crystalline polyol (C1) obtained by reacting an aliphatic dicarboxylic acid with an aliphatic diol and / or a cyclic ether The crystalline polyol (C1) is not particularly limited as long as it is a crystalline polyol obtained by reacting an aliphatic dicarboxylic acid with an aliphatic diol and / or a cyclic ether. Specifically, the crystalline polyol (C1) may be a crystalline polyol obtained by a condensation reaction between an aliphatic dicarboxylic acid and an aliphatic diol; a crystalline polyol obtained by an esterification reaction between an aliphatic dicarboxylic acid and a cyclic ether; or a crystalline polyol obtained by an esterification reaction between an aliphatic dicarboxylic acid and an aliphatic diol and a cyclic ether.

[0026] Aliphatic dicarboxylic acids (E) The aliphatic dicarboxylic acid is not particularly limited, and examples thereof include succinic acid, adipic acid, sebacic acid (decanedioic acid), and dodecamethylene dicarboxylic acid. Among them, preferred aliphatic dicarboxylic acids are adipic acid, sebacic acid, dodecamethylene dicarboxylic acid, and 1,12-dodecane dicarboxylic acid, and more preferred is sebacic acid. The dicarboxylic acid may be a derivative of a carboxylic acid. Examples of such derivatives include dialkyl esters such as dimethyl esters and diethyl esters of the dicarboxylic acids exemplified above.

[0027] Aliphatic diol (F1) The aliphatic diol is not particularly limited, and examples thereof include ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol, 2-methyl-1,4-butanediol, neopentyl glycol, 1,6-hexanediol, 2-methyl-1,5-pentanediol, 3-methyl-1,5-pentanediol, etc. Among these, the aliphatic diol is preferably an aliphatic diol having 2 to 10 carbon atoms, more preferably an aliphatic diol having 4 to 8 carbon atoms, and further preferably ethylene glycol, 1,4-butanediol, and 1,6-hexanediol.

[0028] Cyclic Ether (F2) The cyclic ether is not particularly limited, and examples thereof include oxirane (also called epoxide, ethylene oxide, or alkylene oxide), oxetane, and the like.

[0029] Among these, the crystalline polyol (C1) is preferably a polyester polyol obtained by condensation polymerization using adipic acid or sebacic acid as the aliphatic dicarboxylic acid (E) and an aliphatic diol having 4 to 8 carbon atoms as the aliphatic diol (F1), since the crystalline polyol (C1) imparts an appropriate melting point and recrystallization (solidification) time to the crystalline urethane prepolymer and improves workability.

[0030] Crystalline hydrogenated polyolefin polyol (C2) The crystalline hydrogenated polyolefin polyol (C2) is not particularly limited, and examples thereof include hydrogenated polyisoprene polyol and hydrogenated polybutadiene polyol.

[0031] The hydrogenated polyolefin polyol (C2) is not particularly limited, and examples thereof include hydrogenated polybutadiene polyols, hydrogenated polyisoprene polyols, and hydroxyl-modified polyolefins that can be obtained by reacting an amino alcohol with an acid-modified polyolefin obtained by modifying a polyolefin with an unsaturated (poly)carboxylic acid (anhydride), as described in JP2018-076428A and the like.

[0032] The commercially available crystalline hydrogenated polyolefin polyol (C2) is not particularly limited, and examples thereof include Polytail H [hydrogenated polybutadiene polyol, manufactured by Mitsubishi Chemical Corporation].

[0033] The average hydroxyl value of the crystalline polyol (C1) or the crystalline hydrogenated polyolefin polyol (C2) is usually from 5 to 160 mgKOH / g, preferably from 15 to 1100 mgKOH / g, and more preferably from 20 to 80 mgKOH / g. In this specification, the "average hydroxyl value" refers to the value of the hydroxyl value of the crystalline polyol (C1) or the crystalline hydrogenated polyolefin polyol (C2) when one type is used alone, and refers to the average value of the hydroxyl values ​​of the hydroxyl-containing compounds when two or more types are used in combination, calculated by multiplying the hydroxyl values ​​of the multiple hydroxyl-containing compounds by their blending ratio and adding them up. In this specification, the hydroxyl value is measured in accordance with JIS K1557-1:2007, Method A.

[0034] The crystalline polyol (C) used in the crystalline urethane prepolymer (A) preferably contains a crystalline polyol (C1) because the difference between the melting point and the freezing point is large and the workability is improved. In the present disclosure, the freezing point can be rephrased as the crystallization temperature.

[0035] Isocyanate Compounds (D) The isocyanate compound (D) 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.

[0036] The isocyanate compound (D) is not particularly limited and may be, for example, (D1) an aliphatic polyisocyanate compound, (D2) alicyclic polyisocyanate compounds, (D3) Aromatic polyisocyanate compounds Polyisocyanate compounds such as; The modified polyisocyanate compound (D-1) (e.g., (d-1a) Isocyanurate (d-1b) Carbodiimide compound, (d-1c) adduct, (d-1d) Biuret form, (d-1e) Allophanate, etc.); The polynuclear derivative (D-2) of the above polyisocyanate compound is also included.

[0037] Examples of the aliphatic polyisocyanate compound (D1) include tetramethylene diisocyanate, dodecamethylene diisocyanate, 1,6-hexamethylene diisocyanate (HDI), 2,2,4-trimethylhexamethylene diisocyanate, 2,4,4-trimethylhexamethylene diisocyanate, lysine diisocyanate, 2-methylpentane-1,5-diisocyanate, 3-methylpentane-1,5-diisocyanate, and 1,5-pentamethylene diisocyanate, and preferably 1,6-hexamethylene diisocyanate (HDI).

[0038] In addition, the (D1) aliphatic polyisocyanate compound is preferably an allophanate-modified or urethane-modified aliphatic polyisocyanate compound (D1a-1). For example, in the present disclosure, a polyisocyanate compound having an isocyanate group at its end derived from 1,6-hexamethylene diisocyanate (hereinafter abbreviated as "HDI") can be used. Specific examples of such compounds include Asahi Chemical Industry Co., Ltd.'s Duranate (registered trademark, hereinafter abbreviated) A201H, D101, D201, TKA-100, TSA-100, TSS-100, TSE-100, TLA-100, etc.

[0039] Examples of the (D2) alicyclic polyisocyanate compound 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(isocyanatemethyl)cyclohexane.

[0040] The hydrogenated product of 4,4'-diphenylmethane diisocyanate used in the present disclosure is a polyisocyanate obtained by hydrogenating 4,4'-diphenylmethane diisocyanate (hereinafter abbreviated as MDI). A specific example of such a product is WANNATE (registered trademark) HMDI manufactured by Wanka Chemical Japan.

[0041] Examples of the aromatic polyisocyanate compound (D3) 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). Specific examples of these include Millionate (registered trademark, hereafter abbreviated) MR-200 (a mixture of MDI and its polynuclear derivatives) manufactured by Tosoh Corporation.

[0042] (D3) An example of the modified aromatic polyisocyanate compound (a) is (d-2) a carbodiimide derivative of 4,4'-diphenylmethane diisocyanate (MDI). In the present disclosure, 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 MTL manufactured by Tosoh Corporation.

[0043] The viscosity of the isocyanate compound (D) 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 an aromatic polyisocyanate compound and its modified product and polynuclear product (preferably a carbodiimide product and polynuclear product of an aromatic polyisocyanate compound), 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 an aliphatic polyisocyanate compound and its modified product and polynuclear product, 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.

[0044] The NCO content of the isocyanate compound (D) is not particularly limited, but is, for example, 15 to 45%, more preferably 20 to 40%, and further preferably 20 to 35%.

[0045] As the isocyanate compound (D), from the viewpoint of excellent moisture resistance and suppressing the deterioration of electrical insulation, it is preferable to use (Da-1) an allophanate-modified or urethane-modified polyisocyanate compound (more preferably (D1a-1) an allophanate-modified or urethane-modified aliphatic polyisocyanate compound), (D3) 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); (D3) A carbodiimide compound 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.

[0046] As the isocyanate compound (D), 4,4'-diphenylmethane diisocyanate or a modified or polynuclear compound thereof is more preferable, and specifically, (D3) 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), and A carbodiimide-modified product of 4,4'-diphenylmethane diisocyanate, that is, a polyisocyanate having a carbodiimide group derived from 4,4'-diphenylmethane diisocyanate (carbodiimide-modified MDI) is more preferred.

[0047] Among these, preferred commercially available isocyanate compounds (D) include, for example, Duranate D201 (manufactured by Asahi Kasei Corporation), Duranate A201H (manufactured by Asahi Kasei Corporation), Millionate MT (manufactured by Tosoh Corporation), Millionate NM (manufactured by Tosoh Corporation), Millionate MR-200 (manufactured by Tosoh Corporation), Millionate MTL (manufactured by Tosoh Corporation), and the like, with Millionate MT (manufactured by Tosoh Corporation) and Duranate D201 (manufactured by Asahi Kasei Corporation) being more preferred.

[0048] The isocyanate compound (D) may be used alone or in any combination of two or more kinds.

[0049] The content of the isocyanate compound (D) is not particularly limited as long as it is an amount that can be used in a polyurethane resin composition. The content is, for example, usually 0.01 to 70 mass%, preferably 0.1 to 50 mass%, more preferably 1 to 40 mass%, and particularly preferably 1.5 to 35 mass%, based on 100 mass% of the crystalline urethane prepolymer (A). By blending the isocyanate compound (D) with the crystalline urethane prepolymer (A) in the above ratio, foaming caused by carbon dioxide during moisture curing is suppressed, while the melt viscosity is reduced, workability is improved, and electrical insulation is also improved. The content of the isocyanate compound (D) 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 crystalline polyol (C1) or the crystalline hydrogenated polyolefin polyol (C2).

[0050] When two or more kinds of isocyanate compounds (D) are blended in the crystalline urethane prepolymer (A), the total amount thereof can be adjusted according to the content of the above-mentioned isocyanate compound (D).

[0051] When the crystalline urethane prepolymer (A) contains an aromatic polyisocyanate compound (D3), the content thereof is usually 0.01 to 70 mass%, preferably 0.1 to 50 mass%, more preferably 1 to 40 mass%, and particularly preferably 1.5 to 35 mass%, relative to 100 mass% of the crystalline urethane prepolymer (A). By blending the aromatic isocyanate compound (D3) with the crystalline urethane prepolymer (A) in the above ratio, foaming caused by carbon dioxide during moisture curing is suppressed, while the melt viscosity is reduced, improving workability and electrical insulation.

[0052] The amount of the isocyanate compound (D) and the crystalline polyol (C1) or the crystalline hydrogenated polyolefin polyol (C2) is in such a range that the NCO / OH ratio (INDEX), which is the ratio of the number of moles of isocyanate groups in the isocyanate compound to the number of moles of hydroxyl groups in the total of the polyol, is usually 1.3 to 4, preferably 1.5 to 3.5, and more preferably 1.8 to 3.

[0053] Amorphous urethane prepolymer (B) The amorphous urethane prepolymer (B) is not particularly limited, and may be, for example, an amorphous urethane prepolymer obtained by reacting at least one hydroxyl group-containing compound (G) selected from the group consisting of polyether polyol, polyester polyol, polybutadiene polyol, and castor oil polyol with an isocyanate compound (D). The amorphous urethane prepolymer (B) means a urethane prepolymer that does not have a regular long-chain molecular structure and does not have a crystalline structure. Among them, the amorphous urethane prepolymer is preferably a liquid at room temperature (25°C).

[0054] Hydroxyl-containing compounds (G) The hydroxyl group-containing compound (G) is not particularly limited, and examples thereof include (G1) polyether polyol, (G2) polyester polyol, (G3) polycarbonate diol, (G4) polyolefin polyol, and (G5) silicone polyol.

[0055] (G1) 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, and butylene oxide 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 thereof include polyethylene glycol, polypropylene glycol, polytetramethylene glycol, propylene oxide adducts of bisphenol A (bisphenol ether polyols), and polyether carbonate diols.

[0056] The hydroxyl value of the polyether polyol (G1) is preferably from 1 to 600 mgKOH / g, more preferably from 10 to 400 mgKOH / g, and particularly preferably from 20 to 150 mgKOH / g.

[0057] The average number of functional groups of the polyether polyol (G1) is usually 1.5 to 5, preferably 2 to 4, and more preferably 1.8 to 2.3.

[0058] The number average molecular weight (Mn) of the polyether polyol (G1) 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.

[0059] The above (G1) polyether polyols can be used alone or in combination of two or more. Among these, the (G1) polyether polyol is preferably polypropylene diol, polytetramethylene glycol, or a propylene oxide adduct of bisphenol A (bisphenol ether polyol).

[0060] The content of the polyether polyol (G1) is usually 0 to 100 parts by mass, preferably 0 to 70 parts by mass, more preferably 1 to 60 parts by mass, and even more preferably 5 to 50 parts by mass, relative to 100 parts by mass of the hydroxyl group-containing compound (G).

[0061] (G2) Polyester polyol The polyester polyol (G2) is not particularly limited, and examples thereof include condensation type polyester polyols, castor oil-based polyols, and the like.

[0062] Condensation type polyester polyols include aliphatic dicarboxylic acids (succinic acid (C4H6O4), adipic acid (C6H 10 O4), azelaic acid (C9H 16 O4), Sebacic acid (C 10 H 18O4), fumaric acid (C4H4O4), maleic acid (C4H4O4), 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 thereof. Among them, the condensation type polyester polyol is preferably a polyvalent carboxylic acid having 2 to 10 carbon atoms or an ester-forming derivative thereof, and more preferably a polyvalent carboxylic acid such as adipic acid, sebacic acid, isophthalic acid, etc., reacted with a diol such as ethylene glycol, propylene glycol, butylene glycol, polyethylene glycol, or polypropylene glycol.

[0063] Specific examples of the condensation type polyester polyol 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 the poly(butylene adipate / butylene terephthalate) copolymer diol include poly(3-methylpentylene adipate / 3-methylpentylene terephthalate) copolymer diol and the like.

[0064] Commercially available condensation polyester polyols include, for example, Polylite (registered trademark, hereinafter abbreviated) OD-X-286, OD-X-102, OD-X-355, OD-X-2330, OD-X-240, OD-X-668, OD-X-2108, OD-X-2376, OD-X-2044, OD-X-688, OD-X-2068, OD-X-2547, and OD -X-2420, OD-X-2523, OD-X-2555, OD-X-2560, Kuraray Co., Ltd. polyol P-510, P-1010, P-2010, P-3010, P-4010, P-5010, P-6010, F-510, F-1010, F-2010, F-3010, P-1011, P-2011, P-2013, P-2030, N-2010, PNNA-2016; Sun-Estar 2610 [polyethylene adipate diol with Mn=1,000, manufactured by Sanyo Chemical Industries, Ltd.], Sun-Estar 4620 [polytetramethylene adipate diol with Mn=2000], Sun-Estar 2620 [polyethylene adipate diol with Mn=2000, manufactured by Sanyo Chemical Industries, Ltd.], Kuraray Polyol P-2010 [poly-3-methyl-1,5-pentylene adipate diol with Mn=2000], Kuraray Polyol P-3010 [poly-3-methyl-1,5-pentylene adipate diol with Mn=3000], Kuraray Polyol P-6010 [Poly-3-methyl-1,5-pentylene adipate diol with Mn=6000], Kuraray Polyol P-520 [Poly-3-methyl-1,5-pentylene terephthalate diol with Mn=500], Kuraray Polyol P-1020 [Poly-3-methyl-1,5-pentylene terephthalate diol with Mn=1000], Kuraray Polyol P-2020 [Poly-3-methyl-1,5-pentylene terephthalate diol with Mn=2000], Kuraray Polyol P-530 [Poly-3-methyl-1,5-pentylene isophthalate diol with Mn=500] terephthalate diol], Kuraray Polyol P-1030 [poly-3-methyl-1,5-pentylene isophthalate diol with Mn=1000], Kuraray Polyol P-2030 [poly-3-methyl-1,5-pentylene isophthalate diol with Mn=2000], Kuraray Polyol P-1011 [poly(3-methyl-1,5-pentylene adipate / 3-methyl-1,5-pentylene terephthalate) copolymer diol with Mn=1,000], Kuraray Polyol P-2011 [poly(3-methyl-1,5-pentylene adipate / 3- Examples of suitable poly(3-methyl-1,5-pentylene terephthalate) copolymer diols include Kuraray Polyol P-1012 [poly(3-methyl-1,5-pentylene adipate / 3-methyl-1,5-pentylene isophthalate) copolymer diols with Mn=1000], Kuraray Polyol P-1012 [poly(3-methyl-1,5-pentylene adipate / 3-methyl-1,5-pentylene isophthalate) copolymer diols with Mn=2000], and Kuraray Polyol P-2050 [poly-3-methyl-1,5-pentylene sebacate diol with Mn=2000].

[0065] The castor oil-based polyol is not particularly limited, and examples thereof include castor oil, castor oil derivatives, etc. As the polyester polyol, castor oil-based polyol is preferred.

[0066] Commercially available castor oil-based polyols include URIC H-1824, URIC H-30, URIC Y-403, URIC HF-1300, URIC HF-2009, and URIC PH-5001 manufactured by Ito Oil Mills, Ltd.

[0067] Examples of the castor oil derivatives include castor oil fatty acid, hydrogenated castor oil obtained by hydrogenating castor oil or castor oil fatty acid, transesterification products of castor oil and other fats and oils, reaction products of castor oil and polyhydric alcohol, esterification products of castor oil fatty acid and polyhydric alcohol, and compounds obtained by addition polymerization of these with alkylene oxide, etc. Among the above castor oil-based polyols, it is preferable to use esterification products of castor oil or castor oil fatty acid and polyhydric alcohol.

[0068] The hydrogenated castor oil is, for example, that disclosed in JP-A-2-298574. The hydrogenated castor oil can be obtained by hydrogenating the above-mentioned castor oil-based polyol.

[0069] The average hydroxyl value of the castor oil-based polyol is preferably from 5 to 400 mgKOH / g, and more preferably from 10 to 200 mgKOH / g.

[0070] The average number of functional groups of the castor oil-based polyol is usually 1.5 to 3.5, more preferably 1.7 to 3, and even more preferably 1.9 to 2.7.

[0071] The number average molecular weight (Mn) of the above castor oil-based polyol is usually in the range of 100 to 5,000, preferably in the range of 200 to 4,000, and more preferably in the range of 300 to 3,500.

[0072] 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 measuring device, Shodex GPC System21 manufactured by Showa Denko K.K., a column, Shodex LF-804 / KF-803 / KF-804 manufactured by Showa Denko K.K., and NMP as a mobile phase at a column temperature of 40°C, and can be calculated using a calibration curve of standard polystyrene.

[0073] The condensation type polyester polyol may be 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.

[0074] The average hydroxyl value of the condensation type polyester polyol is preferably from 5 to 400 mgKOH / g, and more preferably from 10 to 200 mgKOH / g.

[0075] 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.

[0076] The number average molecular weight (Mn) of the condensation type polyester polyol is usually in the range of 100 to 6,000, preferably in the range of 200 to 5,000, and more preferably in the range of 300 to 4,000.

[0077] The polyester polyols may be used alone or in combination of two or more. The polyester polyol is usually present in an amount of 0 to 100% by mass, preferably 10 to 95% by mass, and more preferably 20 to 90% by mass, relative to 100% by mass of the hydroxyl group-containing compound (G).

[0078] The hydroxyl group-containing compound is not particularly limited as long as it has an average hydroxyl value of 20 to 150 mgKOH / g and the average functionality can be adjusted to 1.5 to 3.5, and it is possible to use compounds that are conventionally used as polyol components in polyurethane resin compositions.

[0079] (G3) Polycarbonate polyol The polycarbonate polyol is not particularly limited, and examples thereof include reaction products of polyols and carbonate compounds such as dialkyl carbonates, alkylene carbonates, and diaryl carbonates.

[0080] Examples of the dialkyl carbonate include dimethyl carbonate and diethyl carbonate. Examples of the alkylene carbonate include ethylene carbonate. Examples of the diaryl carbonate include diphenyl carbonate. 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 various polycarbonate polyols with carboxyl group-containing compounds; and the above various polycarbonate polyols. Examples of the polycarbonate polyol include polycarbonate polyols obtained by etherification reaction of the above-mentioned various polycarbonate polyols with ester compounds, polycarbonate polyols obtained by transesterification reaction of the above-mentioned various polycarbonate polyols with hydroxyl group-containing compounds, polyester-based polycarbonate polyols obtained by polycondensation reaction of the above-mentioned various polycarbonate polyols with dicarboxylic acid compounds, and copolymerized polyether-based polycarbonate polyols obtained by copolymerizing the above-mentioned various polycarbonate polyols with alkylene oxides. The polycarbonate polyols can be called polycarbonate diols.

[0081] (G4) Polyolefin polyol The polyolefin polyol is not particularly limited, and may be, 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.

[0082] The polyolefin polyols include polyolefin polyols (for example, polybutadiene polyols, polyisoprene polyols), hydrogenated polyolefin polyols (hydrogenated polyolefin polyols), and the like.

[0083] Examples of polyolefin polyols include polybutadiene polyols, polyisoprene polyols, etc. Examples of 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, hereinafter omitted) series" (R-45M, R-45HT, CS-15, CN-15, etc.) manufactured by ARCO Corporation, USA, "Krasol series" (LBH-P2000, LBH 2000, LBH-P3000, LBH 3000, etc.) manufactured by Cray Valley, and polyisoprene polyols ["Poly ip" manufactured by Idemitsu Kosan Co., Ltd.].

[0084] Examples of hydrogenated polyolefin polyols (hydrogenated polyolefin polyols) include hydrogenated polybutadiene polyols, hydrogenated polyisoprene polyols, etc. 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.], Krasol series (HLBH-P2000, HLBH-P 3000, etc.) manufactured by Cray Valley, and hydrogenated polyolefin polyols [Epole manufactured by Idemitsu Kosan Co., Ltd.].

[0085] The hydroxyl value of the polyolefin polyol is preferably from 10 to 120 mgKOH / g, more preferably from 25 to 110 mgKOH / g, and particularly preferably from 30 to 100 mgKOH / g.

[0086] The average number of functional groups of the polyolefin-based polyol is usually 1.5 to 5, preferably 1.6 to 3, and more preferably 1.7 to 2.5.

[0087] The number average molecular weight (Mn) of the polyolefin-based polyol is usually in the range of 100 to 5,000, preferably in the range of 1,000 to 4,000, and more preferably in the range of 1,500 to 3,500.

[0088] The hydroxyl group content of the polyolefin polyol is not particularly limited and is usually from 0.001 to 3 mol / kg, preferably from 0.01 to 2 mol / kg, and more preferably from 0.1 to 1.2 mol / kg.

[0089] The viscosity of the polyolefin polyol (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.

[0090] The iodine value of the polyolefin polyol 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.

[0091] The polyolefin-based polyols may be used alone or in combination of two or more. Among them, as the polyolefin polyol, polybutadiene polyol is preferable, and polybutadiene polyol having a number average molecular weight (Mn) of 1200 or more and a hydroxyl value of 20 to 150 mgKOH / g is more preferable.

[0092] The content of the polyolefin polyol is preferably from 0 to 70 parts by mass, more preferably from 3 to 60 parts by mass, and further preferably from 5 to 55 parts by mass, based on 100 parts by mass of the hydroxyl group-containing compound (G).

[0093] (G5) Silicone polyol The silicone polyol is not particularly limited, and examples thereof include dimethylpolysiloxane having two or more hydroxyl groups and / or organic groups having a hydroxyl group introduced at the terminal and / or side chain thereof, etc. Preferable examples of the silicone polyol include carbinol-modified silicone oil, polyether-modified silicone oil, and silanol-modified silicone oil. Examples of commercially available silicone polyols include "Silaplane FMDA26" manufactured by JNC Corporation, and "Shin-Etsu Silicones" manufactured by Shin-Etsu Chemical Co., Ltd., carbinol-modified types: KF-6000, KF-6001, KF-6002, KF-6003, X-22-170BX, silanol-modified types: X-21-5841, KF-9701, and diol-modified type: X-22-176F.

[0094] As the hydroxyl group-containing compound (G), it is preferable to use at least one selected from the group consisting of polyether polyols, polyester polyols, polybutadiene polyols, and castor oil polyols. The hydroxyl-containing compound (G) used in the present disclosure may further contain polyol compounds (sometimes referred to as other polyols) other than the above (G1) to (G5).

[0095] Examples of other polyols include dimer acid polyols, polycarbonate polyols, polycaprolactone polyols, acrylic polyols, amine polyols, and hydrogenated versions of these polyols.

[0096] The dimer acid polyol is not particularly limited, and for example, a known dimer acid polyol can be used.

[0097] The polycaprolactone polyol is not particularly limited, and examples thereof include caprolactone-based polyester diols obtained by ring-opening polymerization of cyclic ester monomers such as ε-caprolactone and δ-valerolactone.

[0098] Examples of the acrylic polyol include copolymers obtained by copolymerizing a hydroxyl group-containing acrylate with a copolymerizable vinyl monomer copolymerizable with the hydroxyl group-containing acrylate.

[0099] Examples of hydroxyl group-containing acrylates include 2-hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, hydroxybutyl (meth)acrylate, 2,2-dihydroxymethylbutyl (meth)acrylate, polyhydroxyalkyl maleate, and polyhydroxyalkyl fumarate, and preferably 2-hydroxyethyl (meth)acrylate.

[0100] Examples of the copolymerizable vinyl monomer include C 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. 1-12 Alkyl (meth)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.

[0101] The acrylic polyol can be obtained by copolymerizing these hydroxyl group-containing acrylates and copolymerizable vinyl monomers in the presence of a suitable solvent and a polymerization initiator.

[0102] The acrylic polyol includes, for example, silicone polyol, fluorine polyol, and the like.

[0103] Examples of the fluorine polyol include acrylic polyols in which a fluorine compound containing a vinyl group, such as tetrafluoroethylene or chlorotrifluoroethylene, is blended as a copolymerizable vinyl monomer in the copolymerization of the above-mentioned acrylic polyol.

[0104] The vinyl monomer modified polyol can be obtained by reacting the above-mentioned high molecular weight polyol with a vinyl monomer.

[0105] The amine polyol is not particularly limited, and examples thereof include diethanolamine, triethanolamine, aliphatic amine polyol, etc. Examples of commercially available products of the aliphatic amine polyol include "Sannyx (registered trademark, hereinafter omitted) NP-300" manufactured by Sanyo Chemical Industries, Ltd.

[0106] The freezing point of the hydroxyl group-containing compound (G) is preferably 25°C or lower, more preferably 0°C or lower, and particularly preferably from -5 to -80°C.

[0107] Isocyanate Compounds (D) The isocyanate compound (D) to be reacted with the hydroxyl group-containing compound (G) may be the same as the isocyanate compound (D) used in the crystalline urethane prepolymer (A).

[0108] The content of the isocyanate compound (D) is not particularly limited as long as it is an amount that can be used in a 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 hydroxyl group-containing compound (G). The content of the isocyanate compound (D) 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, relative to 100 parts by mass of the hydroxyl group-containing compound (G).

[0109] When two or more kinds of isocyanate compounds (D) are blended in the amorphous urethane prepolymer (B), the total amount thereof can be adjusted according to the content of the above-mentioned isocyanate compound (D).

[0110] The amorphous urethane prepolymer (B) is preferably an amorphous urethane prepolymer having an unsaturated bond in its chemical structure. When polybutadiene polyol and / or castor oil polyol are used as the hydroxyl group-containing compound (G), these polyols have an unsaturated bond in their structure, and therefore the amorphous urethane prepolymer (B) obtained has an unsaturated bond in its chemical structure, so that a coating film having excellent electrical insulation can be obtained.

[0111] Other Ingredients The polyurethane resin composition of the present disclosure may further contain various additives, as necessary, such as a catalyst, a plasticizer, an inorganic filler, an antifoaming agent, a flame retardant, a flame retardant assistant, 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.

[0112] catalyst The polyurethane composition of the present disclosure may further contain a catalyst, if necessary. As the catalyst, known catalysts can be used, such as metal catalysts and amine catalysts.

[0113] Metal Catalyst Examples of metal catalysts include organometallic catalysts. In this specification, the term "organometallic catalyst" refers to a catalyst containing an organic radical and at least one metal. Here, the term "organic radical" refers to a radical having at least one carbon atom. Examples of the metal of the organometallic catalyst include elements belonging to Group 4 of the periodic table and elements other than Group 4 elements 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 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.

[0114] 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, zirconium monobutoxyacetylacetonate bis(ethylacetylacetonate), and the like.

[0115] 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.

[0116] The elements other than those in Group 4 of the periodic table include, for example, tin, lead, bismuth, and the like. 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.

[0117] Among the organometallic catalysts, organozirconium catalysts are preferred, zirconium chelate complexes are more preferred, and among the zirconium chelate complexes, zirconium tetraacetylacetonate is more preferred. From the viewpoint of safety for the human body and the environment, it is preferable not to use an organotin catalyst as the organometallic catalyst.

[0118] Amine Catalyst Examples of the amine catalyst include reactive amine catalysts and non-reactive amine catalysts. The 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 having at least one hydroxyl group in the molecule. Examples of the amine compound having at least one hydroxyl group in the molecule include 2-dimethylaminoethanol, 6-dimethylamino-1-hexanol, 2-[2-(dimethylamino)ethoxy]ethanol, 1,4-azabicyclo[2.2.2]octane-2-methanol, and the like, and 1,4-azabicyclo[2.2.2]octane-2-methanol is preferred.

[0119] 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, bis(2-morpholinoethyl)ether, and bis(2-dimethylaminoethyl)ether. Among the above amine catalysts, non-reactive amine catalysts are preferred.

[0120] The catalyst content may be within a range that does not impair the effect, 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.

[0121] The catalysts may be used alone or in combination of two or more. The catalyst is preferably an amine catalyst, more preferably a non-reactive amine catalyst.

[0122] Plasticizer The polyurethane resin composition of the present disclosure may further contain a plasticizer, if necessary.

[0123] The plasticizer used in the present disclosure is not particularly limited as long as it has a melting point or solidification point of 120° C. or lower, and examples thereof include ester group-containing plasticizers, phosphorus-based plasticizers, and hydrocarbon-based plasticizers.

[0124] 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.

[0125] Examples of phosphorus-based plasticizers include triphenyl phosphate (TPP), tricresyl phosphate (TCP), trixylenyl phosphate (TXP), and cresyl diphenyl phosphate (CDP).

[0126] Examples of the hydrocarbon plasticizer 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.

[0127] Among these, ester group-containing plasticizers and phosphorus-based plasticizers are preferred, and phosphorus-based plasticizers are more preferred because they not only reduce the melt viscosity and improve workability but also impart flame retardancy to the resin.

[0128] When the polyurethane resin composition of the present disclosure contains a plasticizer, the content of the plasticizer 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.

[0129] The above plasticizers can be used alone or in combination of two or more.

[0130] Inorganic Fillers To the polyurethane resin composition of the present disclosure, an inorganic filler can be added as long as the effects of the present disclosure are not adversely affected.

[0131] The inorganic filler used in the present disclosure is not particularly limited, and examples thereof include metal hydroxides, metal oxides, metal nitrides, natural minerals, zeolites, etc. In addition, 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.

[0132] Examples of metal hydroxides include aluminum hydroxide, magnesium hydroxide, etc. Here, aluminum hydroxide and magnesium hydroxide also act as flame retardants.

[0133] Examples of metal oxides include aluminum oxide (alumina), magnesium oxide, silicon dioxide (silica, etc.), and titanium oxide.

[0134] Examples of metal nitrides include boron nitride, aluminum nitride, and silicon nitride.

[0135] Examples of natural minerals include calcium carbonate, talc (silicate mineral), mica, kaolin, clay, and silica.

[0136] The zeolite is not particularly limited, and any zeolite used in known polyurethane resin compositions can be used.

[0137] Among these, the zeolite is preferably a crystalline hydrous aluminosilicate of an alkali metal or an alkaline earth metal.

[0138] The crystal form of the zeolite is not particularly limited, and examples thereof include A-type, X-type, LSX-type, etc. Among these, the preferred crystal form is A-type.

[0139] The alkali metal or alkaline earth metal in the zeolite is not particularly limited, and examples thereof include potassium, sodium, calcium, lithium, etc. Among these, potassium is preferred.

[0140] The inorganic fillers may be used alone or in combination of two or more.

[0141] When the polyurethane resin composition of the present disclosure contains an inorganic filler, the content of the inorganic filler is preferably 0.1 to 50 mass %, and more preferably 0.3 to 30 mass %, relative to 100 mass % of the polyurethane resin composition.

[0142] The antifoaming agent is not particularly limited, and examples thereof include silicones (oil type, compound type, self-emulsifying type, emulsion type, etc.), alcohols, and the like.

[0143] A preferred silicone-based defoaming agent is a modified silicone-based defoaming agent (particularly one in which polysiloxane has a lipophilic group and is modified with a hydrophilic group).

[0144] The above-mentioned defoaming agents can be used alone or in combination of two or more.

[0145] When an antifoaming agent is contained, its content is not particularly limited, and is preferably from 0.001 to 10 mass %, and more preferably from 0.005 to 5 mass %, relative to 100 mass % of the polyurethane resin composition.

[0146] Examples of the flame retardant include phosphorus-based flame retardants, inorganic flame retardants, bromine-based flame retardants, and chlorine-based flame retardants.

[0147] Examples of the phosphorus-based flame retardant that can be used include red phosphorus, phosphate esters, condensed phosphate esters, aromatic condensed phosphate esters, aliphatic phosphate amidates, and phosphazenes.

[0148] Examples of monomeric aromatic phosphate esters include triphenyl phosphate, tricresyl phosphate, trixylenyl phosphate, tris(isopropylphenyl)phosphate, tris(phenylphenyl)phosphate, trinaphthyl phosphate, cresyl diphenyl phosphate, xylenyl diphenyl phosphate, diphenyl(2-ethylhexyl)phosphate, and di(isopropylphenyl)phenyl phosphate.

[0149] Examples of aromatic condensed phosphate esters include condensed phosphate esters such as trialkyl polyphosphate, resorcinol polyphenyl phosphate, resorcinol poly(di-2,6-xylyl) phosphate, hydroquinone poly(2,6-xylyl) phosphate, and condensates thereof.

[0150] As the aromatic condensed phosphate ester, a wide variety of known commercially available products can be used, such as "PX-200" manufactured by Daihachi Chemical Industry Co., Ltd.

[0151] As the inorganic flame retardant, in addition to aluminum hydroxide and magnesium hydroxide described above as the inorganic filler, for example, antimony trioxide, antimony pentoxide, ammonium borate, zinc borate, etc. can be used. Examples of bromine-based flame retardants include hexabromobenzene, decabromodiphenyl oxide (DBDPO), tetrabromobisphenol A (TBBA), and ethylene bis(pentabromophenyl). Examples of chlorine-based flame retardants include chlorinated paraffin, perchlorocyclopentadecanone, and chlorendic acid.

[0152] Examples of the flame retardant auxiliary include nitrogen-based compounds and radical trapping agents such as hindered amines. Examples of the nitrogen-based compound include melamine cyanurate, triazine compounds, and guanidine compounds.

[0153] When the polyurethane resin composition of the present disclosure contains a flame retardant, the content of the flame retardant or the flame retardant mixture containing the flame retardant and the flame retardant auxiliary is preferably 3 to 30 mass%, more preferably 4 to 25 mass%, and particularly preferably 5 to 20 mass%, relative to 100 mass% of the polyurethane resin composition.

[0154] 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 crosslinkers 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.

[0155] Among these, aromatic alcohol-based crosslinking agents and aliphatic alcohol-based crosslinking agents are preferred, and aliphatic alcohol-based crosslinking agents are more preferred.

[0156] The number average molecular weight of the crosslinking agent is usually 1,000 or less, preferably 500 or less, and more preferably 400 or less.

[0157] When the polyurethane resin composition of the present disclosure contains a crosslinking agent, the content of the crosslinking agent is not particularly limited and is, for example, usually 0.01 to 30 mass%, preferably 0.1 to 20 mass%, and more preferably 1 to 15 mass%, relative to 100 mass% of the polyurethane resin composition.

[0158] The above crosslinking agents can be used alone or in combination of two or more.

[0159] The contents of these components may be appropriately determined according to the intended use from the ranges of normal addition amounts and specifications so as not to impair the desired properties of the polyurethane resin composition.

[0160] Method for producing polyurethane resin composition The method for producing the polyurethane resin composition of the present disclosure is not particularly limited, and the composition can be produced according to any known method used for producing polyurethane resin compositions. For example, a method for producing a polyurethane resin composition according to the present disclosure includes a step of mixing a crystalline urethane prepolymer (A) and an amorphous urethane prepolymer (B). When the polyurethane resin composition of the present disclosure contains a catalyst, a method for producing the polyurethane resin composition of the present disclosure includes, for example, a step of mixing a crystalline urethane prepolymer (A), an amorphous urethane prepolymer (B), and a catalyst.

[0161] The urethane prepolymer used in the present disclosure can be produced by a known method. For example, the crystalline urethane prepolymer (A) can be produced by reacting the isocyanate compound (D) in a reaction vessel with a crystalline polyol (C1) obtained by reacting an aliphatic dicarboxylic acid (E) from which moisture has been removed with an aliphatic diol (F1) and / or a cyclic ether (F2). Alternatively, the crystalline urethane prepolymer (A) can be produced by reacting the isocyanate compound (D) in a reaction vessel with a crystalline hydrogenated polyolefin polyol (C2) from which moisture has been removed. The amorphous urethane prepolymer (B) can be produced by reacting the isocyanate compound (D) in a reaction vessel with at least one hydroxyl group-containing compound (G) selected from the group consisting of polyether polyols, polyester polyols, polybutadiene polyols, and castor oil polyols from which moisture has been removed.

[0162] The crystalline urethane prepolymer (A) and the amorphous urethane prepolymer (B) can usually be produced without a solvent, but may be produced by reacting them in an organic solvent. When reacting them in an organic solvent, an organic solvent such as ethyl acetate, n-butyl acetate, methyl ethyl ketone, or toluene that does not inhibit the reaction can be used, but it is necessary to remove the organic solvent by a method such as heating under reduced pressure during or after the reaction.

[0163] The crystalline urethane prepolymer (A) is preferably reacted in such a manner that the equivalent ratio of the isocyanate groups of the polyisocyanate (D) to 1 equivalent of the hydroxyl groups of the crystalline polyol (C1) or the crystalline hydrogenated polyolefin polyol (C2) is in the range of 1.2 to 5.0, more preferably 1.5 to 3.0. The amorphous urethane prepolymer (B) is reacted preferably in such a range that the equivalent ratio of the isocyanate groups of the polyisocyanate (D) to 1 equivalent of the hydroxyl groups of the hydroxyl group-containing compound (G) is 1.2 to 5.0, more preferably 1.5 to 3.0.

[0164] When producing the crystalline urethane prepolymer (A) and the amorphous urethane prepolymer (B), a urethane-forming catalyst or the like can be used as necessary. The urethane-forming catalyst or the like can be appropriately added at any stage of the reaction.

[0165] The crystalline urethane prepolymer (A) may contain the above-mentioned other components in addition to the isocyanate compound (D), the crystalline polyol (C1) or the crystalline hydrogenated polyolefin polyol (C2). The amorphous urethane prepolymer (B) may contain the above-mentioned other components in addition to the isocyanate compound (D) and the hydroxyl group-containing compound (G).

[0166] Another example of a method for producing the polyurethane resin composition of the present disclosure is a method in which a crystalline polyol (C1) or a crystalline hydrogenated polyolefin polyol (C2) and a hydroxyl group-containing compound (G) are mixed and dehydrated, and then an isocyanate compound (D) is added and reacted. The crystalline polyol (C1) or the crystalline hydrogenated polyolefin polyol (C2) is preferably mixed with the hydroxyl group-containing compound (G) at a temperature of about 90 to 120° C. under reduced pressure. The reaction between the obtained mixture and the isocyanate compound (D) is preferably carried out under a nitrogen gas flow. The reaction temperature is usually about 90 to 110° C., preferably about 100° C., and the reaction time is usually about 1 to 3 hours, preferably about 2 hours.

[0167] When producing the polyurethane resin composition, the crystalline urethane prepolymer (A) is usually 1 to 1000 parts by mass, preferably 10 to 200 parts by mass, and more preferably 25 to 150 parts by mass, per 100 parts by mass of the amorphous urethane prepolymer (B).

[0168] The content of the crystalline urethane prepolymer (A) in the polyurethane resin composition is preferably from 5 to 80 mass%, more preferably from 8 to 65 mass%, and particularly preferably from 10 to 50 mass%, based on 100 mass% of the polyurethane resin composition.

[0169] The content of the amorphous urethane prepolymer (B) in the polyurethane resin composition is preferably from 1 to 90 mass%, more preferably from 3 to 75 mass%, and particularly preferably from 5 to 60 mass%, based on 100 mass% of the polyurethane resin composition.

[0170] Uses of polyurethane resin composition and cured polyurethane resin Applications of the polyurethane resin composition and the cured polyurethane resin of the present disclosure include coating agents, hot melts, covering agents, potting agents, encapsulants, sealing agents, adhesives, etc. Among these, the polyurethane resin composition and the cured polyurethane resin of the present disclosure are preferably used as coating agents (formal coating agents) and potting agents, since they can be used even in small amounts.

[0171] The polyurethane resin composition of the present disclosure is suitably used for electric and electronic components on which electronic circuit mounting boards and the like are mounted. The polyurethane resin composition of the present disclosure is solid at room temperature and immediately solidifies after being poured into electric / electronic components, and therefore has excellent tack-free properties compared to two-component potting agents.

[0172] Furthermore, the polyurethane resin composition of the present disclosure has a melting point of 70° C. or lower, and a freezing point of the polyurethane resin composition of 0° C. or higher and 40° C. or lower. The melting point is preferably 40° C. to 70° C., and more preferably 45° C. to 65° C. The freezing point is preferably 2° C. to 38° C., and more preferably 5° C. to 35° C.

[0173] The melting point of the polyurethane resin composition is measured by differential scanning calorimetry (DSC). Specifically, the melting point can be measured by raising the temperature at 20° C. / min in an air stream together with a standard sample (alumina powder) and detecting the temperature (° C.) at which the maximum endothermic peak is observed. The freezing point is measured by differential scanning calorimetry (DSC measurement method). Specifically, the temperature is lowered from 120°C at 20°C / min in an air stream together with a standard sample (alumina powder), and the temperature (°C) showing the maximum endothermic peak is detected.

[0174] The polyurethane resin composition of the present disclosure has a melt viscosity of 5,000 mPa s or less at 120°C and therefore has excellent castability, and since the crosslinking reaction is accelerated over time after solidification, the composition has excellent high-temperature flow resistance and insulation reliability. The melt viscosity (120° C.) of the polyurethane resin composition of the present disclosure is usually from 100 to 5000 mPa·s, preferably from 200 to 4000 mPa·s, and more preferably from 300 to 3800 mPa·s.

[0175] The solidification time of the polyurethane resin composition of the present disclosure is not particularly limited, but is preferably 5 to 400 seconds, more preferably 10 to 350 seconds, and particularly preferably 15 to 300 seconds.

[0176] The volume resistivity of the polyurethane resin composition of the present disclosure is not particularly limited, but is preferably 1×10 7 ~1×10 18 Ω·m, and more preferably 5×10 10 ~1×10 17 Ω·m, particularly preferably 1×10 11 ~1×10 16 Ω m.

[0177] The polyurethane resin composition of the present disclosure can be used, inter alia, as a hot melt coating agent or a hot melt potting agent.

[0178] The components contained in the hot melt coating agent of the present disclosure are the same as those described in the "Polyurethane Composition" above. The components contained in the hot melt potting agent of the present disclosure are the same as the components described in the "Polyurethane Composition" above.

[0179] Examples of methods for encapsulating electric / electronic components equipped with electronic circuit mounting boards or the like using the polyurethane resin composition, hot melt coating agent, or hot melt potting agent of the present disclosure include a method in which the hot melt potting agent of the present disclosure is melted at a temperature of about 80 to 130°C and ejected using a ejector onto the surface of the electric / electronic component equipped with an electronic circuit mounting board to encapsulate it.

[0180] The polyurethane resin composition of the present disclosure has an isocyanate group at a polymer terminal or within the molecule, which can form a crosslinked structure by reacting with moisture present in the air or on a casing, adherend, or the like to which the polyurethane resin composition is applied. Therefore, the polyurethane resin composition of the present disclosure can form a coating layer (coating film) by reacting with moisture. In the polyurethane resin composition of the present disclosure, the equivalent ratio ([NCO / OH]) of the isocyanate groups in the polyisocyanate (D) to one equivalent of the hydroxyl groups in the crystalline polyol (C) or the hydroxyl group-containing compound (G) is preferably in the range of 1.2 to 5.0, more preferably in the range of 1.5 to 3.0.

[0181] The electronic circuit mounting board of the present disclosure includes a printed circuit board as a carrier layer, electronic components, and the above-mentioned coating. The electronic components are not particularly limited, and known components can be used depending on various applications, and examples thereof include ICs (integrated circuits), CPUs, memories, communication circuits, amplifiers, AD converters, wireless communication units, analog filters, capacitors, resistors, batteries, sensors, etc. One or more of these may be modularized (mounted) on the circuit board. The electric circuit mounting board is preferably configured by combining a coating layer obtained by reacting the polyurethane resin composition of the present disclosure with water or moisture, and a printed circuit board as a carrier layer.

[0182] The printed circuit board is not particularly limited, and examples thereof include copper-clad laminates. Specifically, the copper-clad laminate is formed by laminating rolled copper foil having the above-mentioned characteristics on one or both sides of a resin layer. The resin layer is not particularly limited as long as it has characteristics applicable to printed wiring boards, etc. For example, for rigid PWB, a paper-based phenolic resin, a paper-based epoxy resin, a synthetic fiber cloth-based epoxy resin, a glass cloth and paper composite-based epoxy resin, a glass cloth and glass nonwoven fabric composite-based epoxy resin, and a glass cloth-based epoxy resin can be used. In addition, polyester films, polyimide films, liquid crystal polymer (LCP) films, Teflon (registered trademark) films, polyethylene terephthalate films, polyethylene naphthalate films, etc. can be used for FPCs. The printed circuit board is preferably a board made of a glass cloth-based copper-clad laminate.

[0183] The thickness of the polyurethane resin composition (coating layer) is not particularly limited, but is usually 10,000 μm or less, preferably 10 μm to 1,000 μm, more preferably 30 μm to 800 μm, and further preferably 50 μm to 600 μm. The thickness here indicates the maximum thickness of the resin (layer). The thickness of the coating layer (film) can be measured with a vernier caliper, a ruler, or the like. The amount of the polyurethane resin composition (coating layer) is not particularly limited, but is usually 1000 mg / cm 2 or less, preferably 1 mg / cm 2 ~100mg / cm 2 and more preferably 3 mg / cm 2 ~80mg / cm 2 and more preferably 5 mg / cm 2 ~60mg / cm 2 It is. The amount of the coating layer (film) can be calculated by measuring the area of ​​the applied surface and the weight of the polyurethane resin composition.

[0184] Copper-clad laminates can be used for various printed circuit boards (printed wiring boards (PWBs)). Printed circuit boards include rigid printed circuit boards and flexible printed circuit boards. There are no particular limitations on the type of printed circuit board, but for example, from the viewpoint of the number of layers of the conductor pattern, it can be applied to single-sided PWBs, double-sided PWBs, and multi-layer PWBs (three or more layers); from the viewpoint of the type of insulating board material, it can be applied to rigid PWBs, flexible PWBs (FPCs), and rigid-flex PWBs.

[0185] Electrical and electronic components coated with the polyurethane resin composition of the present disclosure include not only the electronic circuit mounting boards, but also, for example, transformers such as transformer coils, choke coils, and reactor coils, device control boards, various sensors, etc. Such electrical and electronic components are also included in the present disclosure. The electrical and electronic components of the present disclosure can be used in electric washing machines, toilet seats, water heaters, water heaters, water purifiers, baths, dishwashers, power tools, automobiles, motorcycles, battery packs, etc. An example of a method for coating an electronic circuit mounting board with the polyurethane resin composition of the present disclosure includes a method in which the polyurethane resin composition is melted at a temperature of about 80 to 130°C and coated on an electronic circuit mounting board using a coating device.

[0186] When the polyurethane resin composition of the present disclosure is used as a coating agent, the amount used is smaller than that of a potting agent, and a curing process is not required, so that the takt time (the time required to manufacture one product) during coating of an electronic circuit mounting board and the energy consumption during production can be reduced. In addition, the coating agent (protective material, film) has excellent dismantling (recyclability) and can reduce the carbon footprint. The formula for calculating takt time (also sometimes called "pitch time") is "takt time = operating time / production volume." In the manufacturing industry, the shorter the takt time, the higher the productivity.

[0187] In Japan, the "Act on Promotion of Resource Circulation Related to Plastics," also known as the "New Plastics Act" or the "Plastic Resource Circulation Promotion Act," came into effect in 2022. The Act includes "reduce" to reduce the amount of waste generated, "recycle" to regenerate and reuse disposable plastic waste as a resource, "reuse" to repeatedly use plastic products instead of disposing of them, and "renewable" to replace them with renewable ones. Therefore, the polyurethane resin composition and cured product thereof disclosed herein will play a major role in realizing a sustainable society. EXAMPLES

[0188] The polyurethane resin composition of the present disclosure will be specifically described below with reference to examples and comparative examples. However, the examples are merely illustrative, and the present disclosure is not limited to the examples.

[0189] The raw materials used in the examples and comparative examples are shown below.

[0190] Crystalline polyol (C1) obtained by condensation reaction of aliphatic dicarboxylic acid and aliphatic diol c1: Crystalline polyester polyol Decanedioic acid and 1,6-hexanediol are reacted. Average functionality: 2. Number average molecular weight: 3500. Melting point: 65°C. Hydroxyl value: 32mgKOH / g. c2: Crystalline polyester polyol Decanedioic acid and 1,6-hexanediol are reacted. Average functionality: 2. Number average molecular weight: 2000. Melting point: 65°C. Hydroxyl value: 56mgKOH / g. c3: Crystalline polyester polyol Decanedioic acid and 1,6-hexanediol are reacted. Average functionality: 2. Number average molecular weight: 5000. Melting point: 70°C. Hydroxyl value: 23mgKOH / g. c4: Crystalline polyester polyol Dodecanedioic acid and 1,6-hexanediol are reacted. Number average molecular weight: 3500, melting point: 72°C, hydroxyl value: 32mgKOH / g Crystalline hydrogenated polyolefin polyol (C2) c5: crystalline hydrogenated polyolefin polyol (Polytail H (registered trademark)), number average molecular weight: about 2700, melting point 65°C, average number of functional groups: 2.3, hydroxyl value: 48 mgKOH / g, manufactured by Mitsubishi Chemical Corporation

[0191] Hydroxyl-containing compounds (G) g1: Polyether polyol, polypropylene glycol (Sannix PP-2000), average functionality 2, number average molecular weight: approx. 2000, freezing point -35°C, viscosity 310 mPa·s (25°C), hydroxyl value: 56 mgKOH / g, manufactured by Sanyo Chemical Industries, Ltd. g2: Polyester polyol, adipic acid-based polyester polyol (Polylite OD-X-2420), average functionality 2, number average molecular weight: 2000, freezing point 0°C or less, viscosity 5600 mPa·s (25°C), hydroxyl value: 56 mgKOH / g, manufactured by DIC Corporation g3: Castor oil polyol, castor oil modified polyol (Yurik H-1824), average functionality 2.3, number average molecular weight: 1700 (calculated from hydroxyl value), freezing point 0°C or less, viscosity 1110 mPa s, hydroxyl value: 68 mgKOH / g, manufactured by Ito Oil Mills Co., Ltd. g4: Polycarbonate diol, polycarbonate diol mainly composed of 1,6-hexanediol and 1,5-pentanediol (Duranol (registered trademark) T5652), average functionality 2.0, number average molecular weight: 2000, freezing point -20°C or less, viscosity 1000 mPa·s (100°C), hydroxyl value: 56 mgKOH / g, manufactured by Asahi Kasei Corporation g5: Polyolefin polyol, hydroxyl-terminated polybutadiene (Krasol® LBH-P2000), average functionality 2.0, number average molecular weight: 2000, freezing point -20°C or lower, viscosity 13000 mPa·s (25°C), hydroxyl value: 50 mgKOH / g, manufactured by Cray Valley Corporation g6: Polyolefin polyol, hydroxyl-terminated polybutadiene (Poly bd R-45HT), average functionality 2.2, number average molecular weight: 2800, freezing point -20°C or less, viscosity 5000mPa·s (30°C), hydroxyl value: 50mgKOH / g, manufactured by Idemitsu Kosan Co., Ltd. g7: Silicone polyol (Silaprene (registered trademark) FMDA26), number average molecular weight: 15,000, average number of functional groups: 2, specific gravity: 0.97, viscosity: 500 mPa s, manufactured by JNC Corporation

[0192] Isocyanate Compounds (D) d1: Aromatic polyisocyanate (Millionate MT (monomeric MDI)), manufactured by Tosoh Corporation, molecular weight 250, specific gravity 1.23, melting point 40°C d2: Aliphatic polyisocyanate (Duranate D201 (HDI polyisocyanate)), NCO%: 15.8%, viscosity 1800 mPa·s (25°C), manufactured by Asahi Kasei Corporation

[0193] Crystalline urethane prepolymer (A) Example 1: (a1) Crystalline urethane prepolymer (crystalline polyester polyol (c1) + aromatic polyisocyanate (d1)) 100 parts by mass of crystalline polyester polyol (c1) was placed in a separable flask, heated in a 100°C oil bath, depressurized with a vacuum pump, and dehydrated until the moisture content was 0.05% by mass or less. Then, 14.3 parts by mass of aromatic polyisocyanate (d1) was added to the flask, and reacted at 100°C for 2 hours under a nitrogen stream to synthesize crystalline urethane prepolymer (a1). At this time, NCO / OH was adjusted to 2.

[0194] Example 2: (a2) Crystalline urethane prepolymer (crystalline polyester polyol (c2) + aromatic polyisocyanate (d1)) 100 parts by mass of crystalline polyester polyol (c2) was placed in a separable flask, heated in a 100°C oil bath, depressurized with a vacuum pump, and dehydrated until the moisture content was 0.05% by mass or less. Then, 25 parts by mass of aromatic polyisocyanate (d1) was added and reacted at 100°C for 2 hours under a nitrogen stream to synthesize crystalline urethane prepolymer (a2). At this time, NCO / OH was adjusted to 2.

[0195] Example 3: (a3) Crystalline urethane prepolymer (crystalline polyester polyol (c3) + aromatic polyisocyanate (d1)) 100 parts by mass of crystalline polyester polyol (c3) was placed in a separable flask, heated in a 100°C oil bath, depressurized with a vacuum pump, and dehydrated until the moisture content was 0.05% by mass or less. Then, 10.3 parts by mass of aromatic polyisocyanate (d1) was added and reacted at 100°C for 2 hours under a nitrogen stream to synthesize crystalline urethane prepolymer (a3). At this time, NCO / OH was adjusted to 2.

[0196] Example 4: (A4) Crystalline urethane prepolymer (crystalline polyester polyol (C3) + aliphatic polyisocyanate (D2)) 100 parts by mass of crystalline polyester polyol (c3) was placed in a separable flask, heated in a 100°C oil bath, depressurized with a vacuum pump, and dehydrated until the moisture content was 0.05% by mass or less. Then, 22.5 parts by mass of aliphatic polyisocyanate (d2) was added and reacted at 100°C for 2 hours under a nitrogen stream to synthesize crystalline urethane prepolymer (a4). At this time, NCO / OH was adjusted to 2.

[0197] Example 5: (A5) Crystalline urethane prepolymer (crystalline polyester polyol (C4) + aromatic polyisocyanate (D1)) 100 parts by mass of crystalline polyester polyol (c4) was placed in a separable flask, heated in a 100°C oil bath, depressurized with a vacuum pump, and dehydrated until the moisture content was 0.05% by mass or less. Then, 14.3 parts by mass of aromatic polyisocyanate (d1) was added and reacted at 100°C for 2 hours under a nitrogen stream to synthesize crystalline urethane prepolymer (a5). At this time, NCO / OH was adjusted to 2.

[0198] Example 6: (A6) Crystalline urethane prepolymer (crystalline hydrogenated olefin polyol (C5) + aromatic polyisocyanate (D1)) 100 parts by mass of crystalline hydrogenated olefin polyol (c5) was placed in a separable flask, heated in a 100°C oil bath, depressurized with a vacuum pump, and dehydrated until the moisture content was 0.05% by mass or less. Then, 21.4 parts by mass of aromatic polyisocyanate (d1) was added and reacted at 100°C for 2 hours under a nitrogen stream to synthesize crystalline urethane prepolymer (a6). At this time, NCO / OH was adjusted to 2.

[0199] Amorphous urethane prepolymer (B) Example 7: (b1) Amorphous urethane prepolymer (polyether polyol (g1) + aromatic polyisocyanate (d1)) 100 parts by mass of polyether polyol (g1) was placed in a separable flask, heated in a 100°C oil bath, depressurized with a vacuum pump, and dehydrated until the moisture content was 0.05% by mass or less. Then, 25 parts by mass of aromatic polyisocyanate (d1) was added and reacted at 100°C for 2 hours under a nitrogen stream to synthesize amorphous urethane prepolymer (b1). At this time, NCO / OH was adjusted to 2.

[0200] Example 8: (b2) Amorphous urethane prepolymer (polyester polyol (g2) + aromatic polyisocyanate (d1)) 100 parts by mass of polyester polyol (g2) was placed in a separable flask, heated in a 100°C oil bath, reduced pressure with a vacuum pump, and dehydrated until the moisture content was 0.05% by mass or less. Then, 25 parts by mass of aromatic polyisocyanate (d1) was added and reacted at 100°C for 2 hours under a nitrogen stream to synthesize amorphous urethane prepolymer (b2). At this time, the NCO / OH ratio was adjusted to 2.

[0201] Example 9: (b3) Amorphous urethane prepolymer (castor oil polyol (g3) + aromatic polyisocyanate (d1)) 100 parts by mass of castor oil polyol (g3) was placed in a separable flask, heated in a 100°C oil bath, depressurized with a vacuum pump, and dehydrated until the moisture content was 0.05% by mass or less. Then, 30.4 parts by mass of aromatic polyisocyanate (d1) was added and reacted at 100°C for 2 hours under a nitrogen stream to synthesize amorphous urethane prepolymer (b3). At this time, NCO / OH was adjusted to 2.

[0202] Example 10: (b4) Amorphous urethane prepolymer (polyolefin polyol (g5) + aromatic polyisocyanate (d1)) 100 parts by mass of polyolefin polyol (g5) was placed in a separable flask, heated in a 100°C oil bath, depressurized with a vacuum pump, and dehydrated until the moisture content was 0.05% by mass or less. Then, 22.3 parts by mass of aromatic polyisocyanate (d1) was added and reacted at 100°C for 2 hours under a nitrogen stream to synthesize amorphous urethane prepolymer (b4). At this time, NCO / OH was adjusted to 2.

[0203] Example 11: (b5) Amorphous urethane prepolymer (polyolefin polyol (g6) + aromatic polyisocyanate (d1)) 100 parts by mass of polyolefin polyol (g6) was placed in a separable flask, heated in a 100°C oil bath, depressurized with a vacuum pump, and dehydrated until the moisture content was 0.05% by mass or less. Then, 22.3 parts by mass of aromatic polyisocyanate (d1) was added and reacted at 100°C for 2 hours under a nitrogen stream to synthesize amorphous urethane prepolymer (b5). At this time, NCO / OH was adjusted to 2.

[0204] Example 12: (b6) Amorphous urethane prepolymer (polycarbonate polyol (g4) + aliphatic polyisocyanate (d2)) 100 parts by mass of polycarbonate polyol (g4) was placed in a separable flask, heated in a 100°C oil bath, depressurized with a vacuum pump, and dehydrated until the moisture content was 0.05% by mass or less. Then, 54 parts by mass of aliphatic polyisocyanate (d2) was added and reacted at 100°C for 2 hours under a nitrogen stream to synthesize amorphous urethane prepolymer (b6). At this time, NCO / OH was adjusted to 2.

[0205] Example 13: (b7) Amorphous urethane prepolymer (silicone modified polyol (g7) + aliphatic polyisocyanate (d2)) 100 parts by mass of silicone modified polyol (g7) was placed in a separable flask, heated in a 100°C oil bath, depressurized with a vacuum pump, and dehydrated until the moisture content was 0.05% by mass or less. Then, 33.8 parts by mass of aliphatic polyisocyanate (d2) was added and reacted at 100°C for 2 hours under a nitrogen stream to synthesize amorphous urethane prepolymer (b7). At this time, NCO / OH was adjusted to 2. The moisture value was measured using a Karl Fischer moisture meter (manufactured by Kyoto Electronics Manufacturing Co., Ltd.) MKH-710.

[0206] Preparation of Polyurethane Resin Composition In the following Examples 1 to 14 and Comparative Examples 1 to 5, various polyurethane resin compositions were prepared using the components in the compositions and amounts (parts by mass) shown in Tables 1 and 2, according to the following procedure.

[0207] Example 1 (Urethane prepolymer (one-component type)) 60 parts by mass of the crystalline urethane prepolymer (A) (crystalline urethane prepolymer (a1)) and 40 parts by mass of the amorphous urethane prepolymer (B) (amorphous urethane prepolymer (b1)) shown in Table 1 were placed in a separable flask, heated in an oil bath at 100°C, and stirred for 1 hour under a nitrogen stream to prepare polyurethane resin composition 1.

[0208] Examples 2 to 14 (Urethane prepolymer (one-component type)) The crystalline urethane prepolymer (A) and the amorphous urethane prepolymer (B) were mixed in the same manner as in Example 1, except that the components and amounts thereof shown in Tables 1 and 2 were substituted for each other, to prepare polyurethane resin compositions 2 to 14.

[0209] Comparative Examples 1 to 3 (Urethane prepolymer (one-component type)) Comparative polyurethane resin compositions 1 to 3 were prepared by mixing in the same manner as in Example 1, except that the crystalline urethane prepolymer (A) and the amorphous urethane prepolymer (B) were replaced with the components and amounts shown in Table 2.

[0210] Comparative Example 4 (two-component type) 40 parts by mass of crystalline polyester polyol (c1) and 60 parts by mass of polyether polyol (g1) were placed in a separable flask, heated in an oil bath at 100°C, reduced pressure using a vacuum pump, and dehydrated until the moisture content was 0.05% by mass or less. Then, 11 parts by mass of aromatic polyisocyanate (d1) was added and stirred at 100°C under a nitrogen stream for 3 minutes, and then immediately poured into a mold to produce two-component polyurethane resin composition 1 (Table 2).

[0211] Comparative Example 5 (two-component type) 25 parts by mass of crystalline polyester polyol (c1) and 75 parts by mass of polyether polyol (g1) were placed in a separable flask, heated in an oil bath at 100°C, reduced pressure using a vacuum pump, and dehydrated until the moisture content was 0.05% by mass or less. Then, 11 parts by mass of aromatic polyisocyanate (d1) was added and stirred at 100°C under a nitrogen stream for 3 minutes, and then immediately poured into a mold to produce two-component polyurethane resin composition 2 (Table 2).

[0212] Preparation of test pieces The prepared polyurethane resin composition was poured into molding die A of 100×100×1.5 mm. Next, this polyurethane resin composition was cooled at 20° C. for 1 hour, and then allowed to stand at room temperature for 7 days to cure, thereby obtaining a test piece A (100×100×1.5 mm).

[0213] The polyurethane resin compositions of Examples 1 to 14 and Comparative Examples 1 to 5, or test piece A prepared as described above, were used to carry out the following measurements and tests.

[0214] Test Example 1 characteristics Melt Viscosity The viscosity of the polyurethane resin composition was measured using a Brookfield BH type viscometer equipped with a thermosel, the temperature of which was set to 120° C., and a SC4-27 spindle was used for the measurement.

[0215] Melting and freezing points Differential scanning calorimetry (DSC) was used to measure the temperature range from -20°C to 100°C under two conditions: a heating rate of 4°C / min, a nitrogen gas flow rate of 200mL / min, and a heating rate of 4°C / min, a nitrogen gas flow rate of 200mL / min. The melting point (°C) and freezing point (°C) were measured from the peak change in heat quantity.

[0216] Workability Spreadability The coating property was evaluated by applying a polyurethane resin composition molten at 120°C at 30 mg / cm using a coating machine equipped with a curtain spray nozzle (manufactured by Suntool Co., Ltd.). 2 , 50mg / cm 2 , 70mg / cm 2 , and 100 mg / cm 2 A printed circuit board (NEMA / ANSI standard: FR-4) was coated with the above amount, and the surface was evaluated for uneven coating and for the presence or absence of foaming after moisture curing. Evaluation items "5 (◯)": No voids (air bubbles) were observed. "4 (△)": Voids (air bubbles) are present, but they are so small that they do not affect electrical insulation. "3 (x)": No leveling and some areas unpainted. "2 (Swelling)": Swelling occurred after curing (25°C / 50% RH / 1 week). "1 (crack)": Resin cracks occurred after solidification. "0 (Not practicable)": The coating machine does not discharge the material evenly.

[0217] Solidification Time Three sheets of NITFLON (registered trademark) No. 903UL (manufactured by Nitto Denko Corporation) adhesive tape (thickness 0.08 μm) were stacked to a thickness of about 0.24 μm and attached to a glass plate (100 × 100 × 3 mm), and a polyurethane resin composition melted at 120 ° C was applied onto the glass plate, and then the applied tape was used as a guide to pull a metal rotor at a constant speed to form a coating film. The time when the resin no longer adheres to the tip of a matchstick when it is lightly pressed against the coating film was recorded as the solidification time.

[0218] Workability evaluation The workability was evaluated based on the above evaluation score for the coatability and the solidification time according to the following evaluation criteria. "A": "All coating evaluation points are 4 points or more" and "curing time is 50 seconds or more" "B": "There is at least one item with a score of 4 or more in the evaluation of application property" and "The solidification time is less than 50 seconds, or there are less than three items with a score of 3" "C": "There is at least one item with a score of 4 or more in the evaluation score for application property" and "There is at least one item with a score of 2 but less than three" "D": "The coating evaluation score includes 1 or less" or "All coating evaluation scores are 3 or less"

[0219] Electrical insulation: Volume resistivity The volume resistivity of test piece A was measured using a resistance meter (HIOKI, DSM-8104). 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. Note that "Not measurable" in Table 2 means that it was not measured because it was not possible to mold the test piece due to the occurrence of resin cracks.

[0220] Electrical insulation evaluation criteria "A": 5E+11(5×10 11 ) End "B": 5E+10(5×10 10 ) or more than 5E+11(5×10 11 )less than "C": 5E+8(5×10 8 ) or more than 5E+10(5×10 10 )less than "D": "Cracks" occur after solidification, making measurement impossible

[0221] Overall rating 1 The results of "evaluation of workability" and "evaluation of electrical insulation" were evaluated according to the following criteria, with the following points being given: Rating A: 4 points Rating B: 3 points Rating C: 2 points Rating D: 1 point Evaluation criteria for overall evaluation 1 "A": The total score of "evaluation of workability" and "evaluation of electrical insulation" is 7 points or more. "B": The total score for "evaluation of workability" and "evaluation of electrical insulation" is 6 points "C": The total score of "Workability evaluation" and "Electrical insulation evaluation" is 5 points or less. The results are shown in Tables 1 and 2.

[0222] [Table 1]

[0223] [Table 2]

[0224] Among the above Examples 1 to 14, the polyurethane resin compositions of Examples 5, 8 and 10 had a viscosity of 14 mg / cm 2 The coating properties of the amount of the coating were evaluated. Using a coating machine (manufactured by Suntool Co., Ltd.) equipped with a curtain spray nozzle, the polyurethane resin composition of the above example melted at 120°C was applied in a coating amount of 14 mg / cm 2 A printed circuit board (NEMA / ANSI standard: FR-4) was coated with the above amount, and the surface was evaluated for uneven coating and for the presence or absence of foaming after moisture curing. The results are shown in Table 3.

[0225] [Table 3]

[0226] Judgment result The polyurethane resin compositions of Examples 1 to 14 were excellent in workability, and the cured products obtained from these polyurethane resin compositions exhibited excellent electrical insulation properties. On the other hand, the polyurethane resin compositions of Comparative Examples 1 to 3 showed poor results in terms of workability, electrical insulation, and the like. Moreover, the polyurethane resin compositions of Comparative Examples 4 and 5, which are used as two-component types, also showed poor results in terms of workability, electrical insulation, and the like.

[0227] Amount used and recyclability In the present disclosure, for example, the electronic component mounting substrate (FIG. 2) coated with the polyurethane resin composition described in Example 1 has a polyurethane resin composition amount of 15 mg / cm. 2 It was. In contrast, the amount of polyurethane resin composition in the electronic component mounting board protected by potting with a conventional resin composition (Figure 1) is 1000 mg / cm 2 It was. Therefore, the polyurethane resin composition of the present invention requires a significantly smaller amount of potting agent than conventional potting agents, and since the electronic component mounting board is independent and not integrated with the case material, only the electronic circuit mounting board can be recovered at the time of disposal, making it possible to recycle the product.

[0228] Example 8-2 The polyurethane resin composition of Example 8-2 was prepared in the same manner as in Example 8 (hereinafter also referred to as Example 8-1), except that catalyst 1 (bis(2-morpholinoethyl) ether, manufactured by Tokyo Chemical Industry Co., Ltd.) was added in the amount shown in Table 4. Specifically, 40 parts by mass of crystalline urethane prepolymer (A) (crystalline urethane prepolymer (a1)), 60 parts by mass of amorphous urethane prepolymer (B) (40 parts by mass of amorphous urethane prepolymer (b2) + 20 parts by mass of amorphous urethane prepolymer (b4)) (total of 100 parts by mass of (A) and (B)), and 0.05 parts by mass of the catalyst 1 were placed in a separable flask and heated in an oil bath at 100°C under a nitrogen stream for 1 hour to prepare the polyurethane resin composition of Example 8-2.

[0229] Example 8-3 The polyurethane resin composition of Example 8-3 was prepared by mixing in the same manner as in Example 8-2, except that the amount of catalyst 1 added was changed to 0.1 parts by mass.

[0230] Test Example 2 Using the polyurethane resin compositions of Examples 8-2 and 8-3, or the test pieces A obtained from these polyurethane resin compositions, the above-mentioned Test Example 1 (measurement of characteristics, and evaluation of workability and electrical insulation) was carried out, and the following durability was also evaluated. The results are shown in Table 4. The polyurethane resin composition of Example 8 (Example 8-1) was evaluated for durability as follows. The durability results are shown in Table 4 together with the results of Test Example 1 (evaluation of characteristics, workability, and electrical insulation) shown in Table 1.

[0231] Durability Testing High Temperature and Humidity Bias (THB) Test A polyurethane resin composition (Example 8-1, 8-2 or 8-3) was coated on a comb-shaped electrode to a thickness of 0.5 mm, and the electrode was placed in a high-temperature, high-humidity chamber at 85° C. and 85% RH, and a voltage of 100 V was applied. After the test, the sample was left at 23° C. for 1 hour, and then the electrical resistance (Ω) was measured. The electrical resistance was measured initially (before being placed in the high-temperature, high-humidity chamber (0 hour)) and after 1000 hours.

[0232] Tensile Test Test piece A (100 x 100 x 1.5 mm) obtained from the polyurethane resin composition of Example 8-1, 8-2 or 8-3 was punched out with a No. 3 dumbbell die to obtain test piece B, which was subjected to a pressure cooker test (PCT) at 121°C and 100% RH. After the test, the elongation (%) of test piece B was measured in accordance with JIS K6251 using a precision universal testing machine (autograph: manufactured by Shimadzu Corporation). The elongation was measured initially (before being put into the PCT (0 hour)) and after 50 hours.

[0233] Durability test criteria "A": The resistance value (Ω) after 1000 hours at 85°C and 85% RH in the THB test is 1E+10 (1×10 10 ) or more, and the elongation rate after 50 hours at 121℃, 100% RH in the tensile test (PCT) is 200% or more "B": The resistance value (Ω) after 1000 hours at 85°C and 85% RH in the THB test is 1E+10 (1×10 10 ) or more, and the elongation rate after 50 hours at 121℃, 100% RH in the tensile test (PCT) is 100% or more "C": The resistance value (Ω) after 1000 hours at 85°C and 85% RH in the THB test is 1E+10 (1×10 10 ) or less than 100% elongation after 50 hours at 121℃, 100% RH in tensile test (PCT)

[0234] Evaluation criteria for overall evaluation 2 "A": "Overall rating 1" and "Durability test rating" are both "A" "B": Either "Overall Evaluation 1" or "Durability Test Evaluation" is "A" and the other is "B" "C": "Overall rating 1" and "Durability test rating" are both "B" or lower

[0235] [Table 4]

[0236] Judgment result The polyurethane resin compositions of Examples 8-2 and 8-3, in which a catalyst was added to the crystalline urethane prepolymer (A) and the amorphous urethane prepolymer (B), were excellent in workability, similar to the polyurethane resin composition of Example 8-1, which did not contain a catalyst. The cured products obtained from these polyurethane resin compositions not only exhibited excellent electrical insulation properties, but also excellent durability (moisture resistance and heat resistance). The polyurethane resin compositions of Example 8-1, Example 8-2, and Example 8-3 were each poured into a mold A of 100×100×1.5 mm, cooled at 20° C. for 1 hour, and then left at 25° C. and 50% RH for 12 hours to harden. When the cured film of Example 8-1 was heated to 100° C., the resin melted. The cured films of Examples 8-2 and 8-3 had a surface film that did not melt even when heated to 100° C., and the thickness was 200 μm or more in both cases. From these results, it was found that the polyurethane resin compositions of Examples 8-2 and 8-3 had improved moisture curing speeds due to the addition of an amine catalyst.

[0237] From the above results, it was found that the polyurethane resin compositions of Examples 1 to 14, which contain a crystalline urethane prepolymer (A) and an amorphous urethane prepolymer (B), have a melting point of 70° C. or less, and a freezing point of 0° C. or more and 40° C. or less, are excellent in workability, and the cured products obtained from these polyurethane resin compositions exhibit excellent electrical insulation. It was also found that by further adding a catalyst to the crystalline urethane prepolymer (A) and the amorphous urethane prepolymer (B), a polyurethane resin composition can be obtained which has excellent workability and electrical insulation, as well as excellent durability of the cured product. [Industrial Applicability]

[0238] The polyurethane resin composition and cured polyurethane resin of the present disclosure 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, and the like.

Claims

1. A crystalline urethane prepolymer (A); Amorphous urethane prepolymer (B); A polyurethane resin composition comprising: The melting point of the polyurethane resin composition is 70° C. or less, and The polyurethane resin composition has a freezing point of 0°C or higher and 40°C or lower.

2. 2. The polyurethane resin composition according to claim 1, wherein the amorphous urethane prepolymer (B) is an amorphous urethane prepolymer having, in a chemical structure, at least one bond selected from the group consisting of an unsaturated bond, an ether bond, and an ester bond.

3. The amorphous urethane prepolymer (B) is a mixture of at least one hydroxyl group-containing compound (G) selected from the group consisting of polyolefin polyols, polyether polyols, and polyester polyols, The polyurethane resin composition according to claim 1 , which is a compound obtained by reacting with an isocyanate compound (D).

4. The amorphous urethane prepolymer (B) is a mixture of at least one hydroxyl group-containing compound (G) selected from the group consisting of polybutadiene polyols and castor oil polyols, The polyurethane resin composition according to claim 1 , which is a compound obtained by reacting with an isocyanate compound (D).

5. The crystalline urethane prepolymer (A) comprises a crystalline polyol (C) obtained by reacting an aliphatic dicarboxylic acid (E) with an aliphatic diol (F1) and / or a cyclic ether (F2); The polyurethane resin composition according to claim 1 , which is a compound obtained by reacting with an isocyanate compound (D).

6. The polyurethane resin composition according to claim 5, wherein the crystalline polyol (C) has a melting point of 70°C or lower.

7. The polyurethane resin composition according to claim 3 , wherein the hydroxyl group-containing compound (G) has a freezing point of 0° C. or lower.

8. The polyurethane resin composition according to claim 1 , further comprising a catalyst.

9. Volume resistivity is 5×10 １０ The polyurethane resin composition according to claim 1, having a modulus of Ω·m or more.

10. 2. The polyurethane resin composition according to claim 1, having a melt viscosity at 120°C of 100 mPa·s or more and 5000 mPa·s or less.

11. The polyurethane resin composition according to claim 1, which is a moisture-curable type.

12. A conformal coating agent comprising the polyurethane resin composition according to any one of claims 1 to 11.

13. A hot melt coating agent for electronic circuit mounting boards, comprising the polyurethane resin composition according to any one of claims 1 to 11.

14. A coating film obtained from the polyurethane resin composition according to any one of claims 1 to 11.

15. The amount of the coating film is 1 mg / cm ２ ~100mg / cm ２ or the coating film has a thickness of 10 μm to 1000 μm.

16. An electronic circuit mounting board comprising the coating film according to claim 14 and a printed circuit board as a carrier layer.

17. An electric / electronic part coated with the polyurethane resin composition according to claim 1.

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