Two-part curing resin raw material

Abstract

Provided is a two-part curing resin raw material that is curable at room temperature and has high strength, while having a long pot life. A two-part curing resin raw material according to an embodiment comprises a first liquid that contains an active hydrogen compound and a second liquid that contains a polyisocyanate, wherein: the active hydrogen compound contains an aromatic diamine having an alkylthio group; and the polyisocyanate contains an allophanate-modified product of an aliphatic polyisocyanate, which has a viscosity of 1300-3300 Pa·s at 25°C and contains 13-25 mass% of NCO.

Description

Two-component curing resin raw material

[0001] An embodiment of the present invention relates to a two-component curable resin raw material.

[0002] Two-component curing resin raw materials that cure at room temperature to form polyurea are known. For example, Patent Document 1 describes a composition containing a polyisocyanate prepolymer having polyether groups bonded by allophanate groups and a polyamine containing at least two primary amino groups. In more detail, Patent Document 1 describes preparing a polyisocyanate containing allophanate groups using hexane 1,6-diisocyanate, mixing the polyisocyanate with an aromatic diamine, and curing the resulting polyurea film.

[0003] Special Publication No. 2009-510235

[0004] Conventional two-component curing resin raw materials for forming polyurea can be cured at room temperature, but some have a short pot life, which limits their applications. On the other hand, some have a long pot life at room temperature, but the cured product is brittle and may not have sufficient strength.

[0005] In view of the above, an embodiment of the present invention has an object to provide a two-component curable resin raw material that can be cured at room temperature, has high strength, and has a long usable time.

[0006] The present invention includes the following embodiments: [1] A two-component curable resin raw material comprising a first component containing an active hydrogen compound and a second component containing a polyisocyanate, wherein the active hydrogen compound contains an aromatic diamine having an alkylthio group, and the polyisocyanate contains an allophanate-modified aliphatic polyisocyanate having a viscosity of 1300 to 3300 mPa·s at 25°C and an NCO content of 13 to 25% by mass.

[0007] [2] The two-component curable resin raw material according to [1], wherein the allophanate-modified aliphatic polyisocyanate is an allophanate-modified alkylene diisocyanate having 4 to 8 carbon atoms. [3] The two-component curable resin raw material according to [1] or [2], wherein the amount of the aromatic diamine having an alkylthio group in the active hydrogen compound is 50 mass% or more. [4] The two-component curable resin raw material according to any one of [1] to [3], wherein the first component and / or the second component further comprises a filler. [5] The two-component curable resin raw material according to any one of [1] to [4], which is used for sealing electric and electronic components. [6] An electric and electronic component sealed with the two-component curable resin raw material according to any one of [1] to [4].

[0008] According to an embodiment of the present invention, it is possible to provide a two-component curable resin raw material that can be cured at room temperature, has high strength, and has a long usable time.

[0009] The two-component curable resin raw material according to this embodiment comprises a first component containing an active hydrogen compound (A) and a second component containing a polyisocyanate (B), i.e., a combination of the first and second components, and is also referred to as a two-component curable resin composition. The active hydrogen compound (A) contains an aromatic diamine (A1) having an alkylthio group. The polyisocyanate (B) contains an allophanate-modified aliphatic polyisocyanate (B1) having a viscosity of 1300 to 3300 mPa·s at 25°C and an NCO content of 13 to 25% by mass. The first and second components are liquid, i.e., fluid, at room temperature (25°C).

[0010] <First Liquid> [Aromatic diamine (A1) having an alkylthio group] The active hydrogen compound (A) contained in the first liquid includes an aromatic diamine (A1) having an alkylthio group. Here, the active hydrogen compound refers to a compound having an active hydrogen group that reacts with an isocyanate group. Examples of the active hydrogen group include a hydroxy group and an amino group. The aromatic diamine refers to a compound having one or more aromatic ring structures and two amino groups in one molecule. The alkylthio group is an alkylthio group such as -SC ｎ H ２ｎ＋１ (where n is an integer of 1 or more).

[0011] The aromatic diamine (A1) having an alkylthio group is a compound having one or more aromatic ring structures and two amino groups in one molecule, as well as an alkylthio group. As the aromatic diamine (A1), a compound having two amino groups directly bonded to the aromatic ring and an alkylthio group directly bonded to the aromatic ring is preferred. The number of alkylthio groups in one molecule may be one or two or more, but is preferably two.

[0012] The above n in the alkylthio group is preferably an integer of 1 to 5, more preferably an integer of 1 to 3.

[0013] Specific examples of the aromatic diamine (A1) having an alkylthio group include dialkylthiotoluenediamines such as dimethylthiotoluenediamine, diethylthiotoluenediamine, and dipropylthiotoluenediamine, and these may be used alone or in combination of two or more.

[0014] [Active hydrogen compound (A)] The active hydrogen compound (A) preferably consists solely of an aromatic diamine (A1) having an alkylthio group, but may contain other active hydrogen compounds together with the aromatic diamine (A1). From the viewpoint of increasing the glass transition temperature Tg of the cured resin and extending the usable life, the active hydrogen compound (A) preferably contains the aromatic diamine (A1) as a main component. In one embodiment, the amount of the aromatic diamine (A1) having an alkylthio group in the active hydrogen compound (A) is preferably 50% by mass or more, more preferably 70% by mass or more, more preferably 80% by mass or more, even more preferably 90% by mass or more, and may even be 100% by mass.

[0015] Other active hydrogen compounds that may be used in combination with the aromatic diamine (A1) having an alkylthio group include organic compounds having an active hydrogen group, and are preferably aromatic diamines (A2) having no alkylthio group.

[0016] The aromatic diamine (A2) not having an alkylthio group is preferably a compound having two amino groups directly bonded to an aromatic ring. Specific examples of the aromatic diamine (A2) include phenylenediamine, toluenediamine, diethyltoluenediamine, trimethylphenylenediamine, 4,4'-methylenedianiline, 4,4'-methylenebis(2-methylaniline), 4,4'-methylenebis(2-ethylaniline), 4,4'-methylenebis(2-isopropylaniline), 4,4'-methylenebis(2,6-dimethylaniline), 4,4'-methylenebis(2,6-diethylaniline), 4,4'-methylenebis(N-methylaniline), 4,4'-methylenebis(N-ethylaniline), and 4,4'-methylenebis(N-sec-butylaniline), and these may be used alone or in combination. Preferably, an aromatic diamine having a structure in which two amino groups and 0 to 3 alkyl groups are directly bonded to one benzene ring, such as phenylenediamine, toluenediamine, diethyltoluenediamine, or trimethylphenylenediamine, is used, and more preferably, a dialkyltoluenediamine such as diethyltoluenediamine or trimethylphenylenediamine.

[0017] In one embodiment, the active hydrogen compound (A) may contain 50 to 100% by mass of an aromatic diamine (A1) having an alkylthio group and 0 to 50% by mass of an aromatic diamine (A2) having no alkylthio group as an optional component, 70 to 100% by mass of (A1) and 0 to 30% by mass of (A2), 80 to 100% by mass of (A1) and 0 to 20% by mass of (A2), or 90 to 100% by mass of (A1) and 0 to 10% by mass of (A2).

[0018] Examples of other active hydrogen compounds include polyols such as polyether polyols, polyester polyols, polycarbonate polyols, polybutadiene polyols, polyisoprene polyols, castor oil polyols, dimer acid polyols, polycaprolactone polyols, acrylic polyols, ethylene glycol, 1,4-butanediol, octanediol, and trimethylolpropane, and aliphatic diamines.

[0019] [Filler (C)] The first liquid may or may not contain a filler (C). As the filler (C), an inorganic filler is preferred from the viewpoint of increasing thermal conductivity. Examples of inorganic fillers include metal oxides such as silica, alumina, and magnesium oxide, metal hydroxides such as aluminum hydroxide and magnesium hydroxide, and metal nitrides such as aluminum nitride and boron nitride. These may be used alone or in combination.

[0020] When the filler (C) is blended into the first liquid, the amount of the filler (C) is not particularly limited, and may be, for example, 20 to 95% by mass, 50 to 90% by mass, or 70 to 90% by mass relative to 100% by mass of the first liquid.

[0021] [Other Components] The first liquid may be composed of only the active hydrogen compound (A), or may be composed of only the active hydrogen compound (A) and the filler (C). In addition to these components, the first liquid may contain, as necessary, various additives such as a catalyst, an antifoaming agent, a surface treatment agent, an antioxidant, a diluent, a flame retardant, an ultraviolet absorber, a colorant, and a plasticizer, provided that the purpose of this embodiment is not impaired.

[0022] The catalyst used can be one that promotes the reaction between the active hydrogen compound (A) and the polyisocyanate (B). For example, metal catalysts such as organotin catalysts, organolead catalysts, and organobismuth catalysts, various urethane polymerization catalysts such as amine catalysts, and organic acid catalysts such as octylic acid can be used.

[0023] <Second Liquid> [Allophanate-Modified Aliphatic Polyisocyanate (B1)] The polyisocyanate (B) contained in the second liquid contains an allophanate-modified aliphatic polyisocyanate (B1). The allophanate-modified aliphatic polyisocyanate (B1) is an isocyanate compound obtained by addition of an aliphatic polyisocyanate to a urethane bond formed by the reaction of an aliphatic polyisocyanate with an alcohol, and contains an allophanate bond (—NH—CO—N—CO ２ -).

[0024] In this embodiment, the allophanate-modified product (B1) has a viscosity at 25° C. of 1,300 to 3,300 mPa·s and an NCO content of 13 to 25% by mass.

[0025] When the viscosity of the allophanate-modified product (B1) at 25°C is 1300 mPa·s or more, curing at room temperature becomes possible, and the strength of the room-temperature-cured product can be increased. When the viscosity is 3300 mPa·s or less, uniformity during mixing with the first liquid is improved, the strength of the room-temperature-cured product can be increased, and the viscosity of the second liquid when blended with a filler and the viscosity of the mixed liquid when mixed with the first liquid can be reduced. The viscosity of the allophanate-modified product (B1) at 25°C is preferably 1400 to 3000 mPa·s, more preferably 1500 to 2500 mPa·s, and even more preferably 1600 to 2000 mPa·s.

[0026] In this specification, the viscosity of the allophanate-modified product (B1) is a value measured using a BM-type rotational viscometer (manufactured by Brookfield) with a rotor No. 4 at a rotation speed of 60 rpm in an atmosphere of 25°C.

[0027] By ensuring that the NCO content of the allophanate-modified product (B1) is 13% by mass or more, the strength of the cured resin can be increased and the glass transition temperature Tg can be raised. It is practically difficult to synthesize an allophanate-modified product having an NCO content of more than 25% by mass. The NCO content of the allophanate-modified product (B1) is preferably 15 to 22% by mass, more preferably 15.5 to 20.0% by mass.

[0028] In this specification, the NCO content is the isocyanate group content measured in accordance with Method A of JIS K1603-1:2007.

[0029] Examples of the aliphatic polyisocyanate constituting the allophanate-modified product (B1) include tetramethylene diisocyanate, pentamethylene diisocyanate, hexamethylene diisocyanate (HDI), dodecamethylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, lysine diisocyanate, 2-methylpentane-1,5-diisocyanate, and 3-methylpentane-1,5-diisocyanate. These may be used alone or in combination of two or more.

[0030] Among these, the aliphatic polyisocyanate constituting the allophanate-modified product (B1) is preferably an alkylene diisocyanate having 4 to 8 carbon atoms, more preferably hexamethylene diisocyanate (HDI) and / or pentamethylene diisocyanate, because it has a lower viscosity when mixed with the first liquid and provides a cured product with a better tensile strain at break.

[0031] [Polyisocyanate (B)] The polyisocyanate (B) may be composed solely of the allophanate-modified product (B1) of the aliphatic polyisocyanate, or may contain other polyisocyanates together with the allophanate-modified product (B1). The polyisocyanate (B) preferably contains the allophanate-modified product (B1) as a main component, and in one embodiment, the amount of the allophanate-modified product (B1) in the polyisocyanate (B) is preferably 40% by mass or more, more preferably 50% by mass or more, more preferably 70% by mass or more, more preferably 80% by mass or more, and even more preferably 90% by mass or more, and may even be 100% by mass.

[0032] The other polyisocyanates that may be used in combination with the allophanate-modified product (B1) are not particularly limited, and examples thereof include various polyisocyanates such as aliphatic polyisocyanates, alicyclic polyisocyanates, and aromatic polyisocyanates.

[0033] Specific examples of the aliphatic polyisocyanate as the other polyisocyanate are as described above, and their isocyanurate, adduct, biuret, or carbodiimide forms may also be used. Furthermore, allophanate-modified forms of aliphatic polyisocyanates other than (B1) may also be used. Examples of alicyclic polyisocyanates include isophorone diisocyanate (IPDI), dicyclohexylmethane 4,4'-diisocyanate (hydrogenated MDI), hydrogenated xylylene diisocyanate, 1,4-cyclohexane diisocyanate, methylcyclohexylene diisocyanate, and 1,3-bis(isocyanatomethyl)cyclohexane, and their modified forms such as isocyanurate, adduct, biuret, allophanate, and carbodiimide may also be used. Examples of aromatic polyisocyanates include diphenylmethane diisocyanate (MDI), polymeric MDI, tolylene diisocyanate (TDI), naphthalene diisocyanate, and xylylene diisocyanate (XDI), and modified forms thereof such as isocyanurates, adducts, biurets, allophanates, and carbodiimides may also be used.

[0034] In one embodiment, the polyisocyanate (B) may contain 40 to 100% by mass of the allophanate-modified aliphatic polyisocyanate (B1) and, as optional components, 0 to 60% by mass of an allophanate-modified aliphatic polyisocyanate (B2) other than (B1) and / or an isocyanurate-modified aliphatic polyisocyanate (B3); 50 to 100% by mass of (B1) and 0 to 50% by mass of (B2) and / or (B3); 60 to 100% by mass of (B1) and 0 to 40% by mass of (B2) and / or (B3); or 70 to 100% by mass of (B1) and 0 to 30% by mass of (B2) and / or (B3).

[0035] [Filler (C)] The second liquid may or may not contain a filler (C). As the filler (C), an inorganic filler is preferred from the viewpoint of increasing thermal conductivity. Specific examples of inorganic fillers are as described above for the first liquid. When an inorganic filler is blended into a two-component curable resin raw material, the inorganic filler generally tends to absorb moisture, and there is a concern that the moisture may react with the polyisocyanate if blended into the second liquid. Therefore, it is preferable that the filler (C), especially the inorganic filler, be blended into the first liquid rather than the second liquid. That is, when a filler (C) is blended into a two-component curable resin raw material, it is preferable that the inorganic filler be blended into the first liquid or both the first and second liquids.

[0036] When the filler (C) is blended into the second liquid, the amount of the filler (C) is not particularly limited, and may be, for example, 20 to 95% by mass, 50 to 85% by mass, or 60 to 80% by mass relative to 100% by mass of the second liquid.

[0037] [Other Components] The second liquid may be composed only of the polyisocyanate (B), or may be composed only of the polyisocyanate (B) and the filler (C), but in addition to these components, it may contain various additives such as a catalyst, an antifoaming agent, a surface treatment agent, an antioxidant, a diluent, a flame retardant, an ultraviolet absorber, a colorant, a plasticizer, etc., as necessary, within the scope of the present embodiment. Specific examples of the catalyst are as described above for the first liquid.

[0038] <Two-component curable resin raw material> The two-component curable resin raw material according to this embodiment is usually composed of a first liquid as a first component and a second liquid as a second component, but may also be provided as a third liquid containing the above-mentioned other components as optional components in addition to the first and second liquids.

[0039] The two-component curable resin raw material can be produced by separately preparing the first and second liquids, and may contain the first and second liquids separately. That is, the resin raw material may be a two-component kit in which the first and second liquids are filled in separate containers. The first and second liquids filled in separate containers are mixed at the time of use, causing the active hydrogen compound (A) and the polyisocyanate (B) to react to produce a thermosetting resin, which then hardens to form a cured product.

[0040] In this case, curing may be carried out by heating or at room temperature. When curing by heating, the heating temperature is not particularly limited and may be, for example, 30 to 120°C or 80 to 120°C. The heating time is not particularly limited and may be, for example, 1 to 3 hours or 2 to 3 hours. When curing at room temperature, the temperature may be, for example, 15 to 30°C or 20 to 30°C. The curing time is not particularly limited and may be, for example, 1 to 24 hours or 3 to 16 hours.

[0041] The pot life of the two-component curable resin raw material is preferably 1 to 30 minutes, more preferably 5 to 15 minutes. The pot life is measured by the method described in the Examples section.

[0042] The resin obtained by curing the two-component curing resin raw material is a polyurea resin when the active hydrogen compound (A) does not contain a polyol, and is a polyurethane-urea resin when the active hydrogen compound (A) contains a polyol. Therefore, the two-component curing resin raw material is also called a two-component curing urea resin raw material or a two-component curing polyurethane-urea resin raw material. Here, the polyurethane-urea resin is a resin that contains both urethane bonds and urea bonds in the main chain.

[0043] In the two-component curing resin raw material, the molar ratio (NCO / active hydrogen group) of isocyanate groups to active hydrogen groups (i.e., the sum of amino groups and hydroxyl groups) is not particularly limited and is, for example, preferably 0.75 to 1.55, more preferably 0.8 to 1.5, more preferably 0.9 to 1.3, and even more preferably 1.0 to 1.2. When the molar ratio (NCO / active hydrogen group) is within the above range, the two-component curing resin raw material is less likely to undergo poor curing.

[0044] <Uses of Two-Component Curing Polyurethane Resin Raw Material> The uses of the two-component curing resin raw material according to this embodiment are not particularly limited, but due to the advantages of its insulating properties and long usable life, it is preferably used for sealing electrical and electronic components. That is, a sealant for electrical and electronic components according to a preferred embodiment comprises the above-described first and second liquids. A sealant for electrical and electronic components is a material for protecting electrical and electronic components from external factors such as heat, moisture, and dust, and is also called a potting agent when it is used for casting.

[0045] The electric and electronic components are not particularly limited, but examples thereof include capacitors such as film capacitors, transformers such as transformer coils, choke coils, and reactor coils, electric cells, electronic substrates such as device control substrates, sensors, wireless communication components, etc. The two-component curing resin raw material according to the embodiment has a high glass transition temperature Tg of the cured product, and therefore can be used in a wide range of applications in the environments in which electric and electronic components are used.

[0046] The two-component curing resin raw material can be used, for example, as a sealant for film capacitors. A film capacitor is a capacitor that uses a polymer film as a dielectric and is obtained by placing the dielectric film in an outer case and filling it with resin. The two-component curing resin raw material is preferably used as the resin to be filled.

[0047] Electrical and electronic components encapsulated using two-component curing resin raw materials can be used in, for example, electric washing machines, toilet seats, water heaters, water purifiers, bathtubs, dishwashers, solar panels, power tools, automobiles, motorcycles, etc.

[0048] The present invention will be explained in more detail below based on examples and comparative examples, but the present invention is not limited thereto.

[0049] Details of each component used in the examples are as follows:

[0050] [Active hydrogen compounds] Dimethylthiotoluenediamine: "Ethacure 300" manufactured by Lonza Diethyltoluenediamine (DETDA): "Ethacure 100" manufactured by Lonza

[0051] [Polyisocyanate] HDI allophanate modified product 1: "Coronate 2785" manufactured by Tosoh Corporation, viscosity (25 ° C) 1800 mPa s, NCO content 19.2 mass% HDI allophanate modified product 2: "Coronate 2793" manufactured by Tosoh Corporation, viscosity (25 ° C) 1900 mPa s, NCO content 16.4 mass% HDI allophanate modified product 3: "Duranate A201H" manufactured by Asahi Kasei Corporation, viscosity (25 ° C) 110 mPa s, NCO content 19.7 mass% HDI isocyanurate modified product 1: "Duranate TPA-100" manufactured by Asahi Kasei Corporation, viscosity (25 ° C) 1500 mPa s, NCO content 23.1 mass% HDI bifunctional prepolymer: "Duranate D101" manufactured by Asahi Kasei Corporation, viscosity (25°C) 500 mPa·s, NCO content 19.7% by mass HDI isocyanurate modified product 2: "Duranate TSE-100" manufactured by Asahi Kasei Corporation, viscosity (25°C) 2000 mPa·s, NCO content 12.0% by mass

[0052] [Other ingredients] Filler: Silica, AGC "HS-208"

[0053] The measurement and evaluation methods used in the examples are as follows.

[0054] [Pot life] For two-component curable resin raw materials, the pot life is the time from mixing the two components until a predetermined viscosity is reached. For the filler-free mixture shown in Example 1, the time until the viscosity reached 10,000 mPa·s was measured at 25°C using a BM-type rotational viscometer (manufactured by Brookfield) with a rotor No. 4 and 60 rpm. For the filler-containing mixture shown in Example 2, the time until the viscosity reached 1,000,000 mPa·s was measured at 25°C using a BH-type rotational viscometer (manufactured by Brookfield) with a rotor No. 07 and 4 rpm.

[0055] [Curability] A two-component mixed liquid obtained by mixing the first and second components of a two-component curable resin raw material was applied to a sheet, and the cured product was checked after heat curing at 120°C for 3 hours or room temperature curing overnight to evaluate whether the physical properties of the cured product could be evaluated. Curability was evaluated based on whether the following physical properties of the cured product, such as glass transition point, hardness, and flexural strength, could be measured. If all three of these items were measurable, the evaluation was given an "A." If only one of the three items could not be measured, the evaluation was given a "B." If two or more of the three items could not be measured, the evaluation was given a "C." Here, "impossible to measure" means that the test piece could not be measured due to breakage during measurement or during the test piece preparation stage, for example.

[0056] [Glass transition temperature Tg] The two-component mixture was applied to a sheet and cured by heating at 120°C for 3 hours or overnight at room temperature to obtain a resin sheet with a thickness of 2 to 3 mm. A 5 mm x 2 cm test piece was cut from the resulting resin sheet, and the glass transition temperature (Tg) was measured using a Rheogel E-4000 manufactured by UBM, with a chuck distance of 20 mm, a fundamental frequency of 10 Hz, and strain in automatic control mode. Tg refers to the temperature at which tan δ reaches its maximum value.

[0057] [Hardness] The two-component mixture was applied to a sheet and cured by heating at 120°C for 3 hours or overnight at room temperature to obtain a 4 mm thick resin sheet. The obtained resin sheet was subjected to a Type D hardness test in accordance with JIS K7312:1996 to measure its hardness. If the resin sheet was destroyed by the indenter during measurement, it was deemed unmeasurable.

[0058] [Bending Strength Measurement] The two-component mixture was applied to a sheet and cured by heating at 120°C for 3 hours or overnight at room temperature to obtain a 4 mm thick resin sheet. The three-point bending strength of the obtained resin sheet was measured in accordance with JIS K7074-1988 using a precision universal testing machine manufactured by Shimadzu Corporation as the measuring device, with a test speed of 2 mm / min and a support distance of 80 mm. The maximum bending modulus and maximum bending stress were measured by the bending test.

[0059] [Example 1] Two-component curable resin raw materials for each Example and Comparative Example were prepared according to the formulations (parts by mass) shown in Tables 1 and 2 below. Specifically, first and second liquids were prepared according to the formulations shown in Tables 1 and 2, respectively, and when multiple components were used, they were prepared by stirring and mixing. The resulting first and second liquids were stirred and mixed according to the "first liquid / second liquid mass ratio" shown in Tables 1 and 2, and the pot life was measured. In addition, the curability, glass transition temperature Tg, hardness, flexural modulus, and maximum flexural stress of the mixed liquid obtained by mixing the first and second liquids were measured and evaluated.

[0060]

[0061]

[0062] The results are shown in Tables 1 and 2. In Comparative Example 1, diethyltoluenediamine, an aromatic diamine having no alkylthio group, was used alone as the active hydrogen compound, and in the pot life test, the first and second liquids immediately cured when mixed. Therefore, a coating film could not be formed, and the coating film properties could not be evaluated.

[0063] In Comparative Example 2, dimethylthiotoluenediamine was used as the active hydrogen compound, and an allophanate-modified HDI with a viscosity below the specified value was used as the polyisocyanate. Therefore, in Comparative Example 2, although the coating film had sufficient physical properties when heat-cured, curing at room temperature was insufficient, and the resulting coating film was brittle, making it impossible to perform hardness or bending tests.

[0064] In Comparative Example 3, an HDI-based bifunctional prepolymer was used as the polyisocyanate, and although the coating film had excellent physical properties when heat-cured, curing at room temperature was insufficient, the resulting coating film was brittle, and the maximum bending stress was significantly lower than when heat-cured.

[0065] In Comparative Examples 4 and 5, in which an isocyanurate-modified HDI was used as the polyisocyanate, sufficient strength was not obtained, or curing at room temperature was insufficient, resulting in poor effectiveness.

[0066] In contrast, Examples 1 to 7 used an aromatic diamine having an alkylthio group as the active hydrogen compound and an allophanate-modified aliphatic polyisocyanate having a predetermined viscosity and NCO content as the polyisocyanate, thereby achieving a long pot life. Furthermore, the compositions were curable not only by heating but also at room temperature, and the resulting cured products had high flexural modulus and maximum flexural stress, as well as high strength. Furthermore, the resulting cured products had a high glass transition temperature (Tg).

[0067] [Example 2] Two-component curable resin raw materials for each example and comparative example were prepared according to the formulation (parts by mass) shown in Table 3 below. Specifically, the first and second liquids were each prepared by stirring and mixing the components shown in Table 3. The resulting first and second liquids were stirred and mixed according to the "first liquid / second liquid mass ratio" shown in Table 3, and the pot life was measured. In addition, the curability, glass transition temperature Tg, hardness, flexural modulus, and maximum flexural stress of the mixed liquid obtained by mixing the first and second liquids were measured and evaluated.

[0068]

[0069] The results are shown in Table 3. As shown in Examples 9 and 10, even when a filler was blended, the use of an aromatic diamine having an alkylthio group in combination with an allophanate-modified aliphatic polyisocyanate having a predetermined viscosity and NCO content enabled curing at room temperature, and the resulting composition had high strength, a high Tg, and a long pot life.

[0070] The various numerical ranges described in this specification can be arbitrarily combined with their respective upper and lower limit values, and all such combinations are considered to be preferred numerical ranges described in this specification. Furthermore, a numerical range described as "X to Y" means from X to Y.

[0071] Although several embodiments of the present invention have been described above, these embodiments are presented as examples and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their omissions, substitutions, modifications, etc. are included within the scope and spirit of the invention, as well as within the scope of the invention described in the claims and their equivalents.

Claims

1. A two-component curable resin raw material comprising a first component containing an active hydrogen compound and a second component containing a polyisocyanate, wherein the active hydrogen compound contains an aromatic diamine having an alkylthio group, and the polyisocyanate contains an allophanate-modified aliphatic polyisocyanate having a viscosity of 1300 to 3300 mPa·s at 25°C and an NCO content of 13 to 25% by mass.

2. The two-component curable resin raw material according to claim 1, wherein the allophanate-modified aliphatic polyisocyanate is an allophanate-modified alkylene diisocyanate having 4 to 8 carbon atoms.

3. The two-component curable resin raw material according to claim 1, wherein the amount of the aromatic diamine having an alkylthio group in the active hydrogen compound is 50% by mass or more.

4. The two-component curable resin raw material according to claim 1, wherein the first liquid and / or the second liquid further contains a filler.

5. The two-component curable resin raw material according to any one of claims 1 to 4, which is used for sealing electrical and electronic components.

6. Electrical and electronic components sealed with the two-component curable resin raw material according to any one of claims 1 to 4.

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