Polyfunctional amine compound having isocyanurate ring

Abstract

To provide a polyfunctional amine compound containing an isocyanurate ring which is excellent in low temperature curability, is excellent in coloration and heat-resistant colorability, and is useful as a curing agent of an epoxy resin.SOLUTION: A polyfunctional amine compound contains an isocyanurate ring represented by the following general formula (I). In the formula, R1 is each independently hydrocarbon which may be the same or different, and n is a repeating number, and represents a real number of 0≤n<10.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a polyfunctional amine compound having an isocyanurate ring. [Background technology]

[0002] Various compounds having an isocyanurate ring are widely used in paints, adhesives, resists, etc. because of their good mechanical strength, dimensional stability, heat resistance, and electrical properties.

[0003] For example, an epoxy resin composition containing 1,3,5-tris(2-carboxyethyl)isocyanurate (hereinafter referred to as CIC acid) as a curing agent has been proposed in Patent Document 1. However, when CIC acid is used as an epoxy resin curing agent, there is a drawback in that a temperature of 200°C or higher is required to obtain a uniform cured product due to its high melting point and poor compatibility with epoxy resins.

[0004] Furthermore, as a curable epoxy resin composition, an epoxy resin composition for sealing optical semiconductors, which contains a compound obtained by reacting triglycidyl isocyanurate with a compound having a phenolic hydroxyl group, an acid anhydride curing agent, and a curing accelerator, has been proposed in Patent Document 2. However, these compositions also have the drawback of requiring a curing temperature of 150°C or higher.

[0005] In addition, as an amine compound having an isocyanurate ring, Patent Document 3 describes the synthesis of a triamine having an isocyanurate ring represented by the following formula (VI) in three steps using methyl nitrophenyl isocyanate as a starting material. Although such aromatic amines are characterized by high reactivity with epoxy resins and high resistance to thermal decomposition, they have problems in that they are poor in transparency, coloration, and heat yellowing resistance.

[0006] [ka]

[0007] Also, Patent Document 4 proposes an amine compound containing an isonurate ring. However, since the compound is not an active amino group but a sterically hindered piperidyl group, it is not usable as a curing agent although it is sufficiently effective as a light stabilizer.

[0008] [ka] (In the formula, R represents a hydrogen atom, a methyl group, or an oxyl group.) [Prior art documents] [Patent documents]

[0009] [Patent Document 1] Japanese Patent Publication No. 59-107742 [Patent Document 2] WO-2014-196515 [Patent Document 3] DE 10 2007 016 272 A1 [Patent Document 4] Patent Publication No. 6-293754 Summary of the Invention [Problem to be solved by the invention]

[0010] The problem to be solved by the present invention is to provide a novel polyfunctional amine compound having an isocyanurate ring, which can be used as a curing agent for epoxy resins, has excellent low-temperature curing properties, and is excellent in coloration and heat-resistant coloration. [Means for solving the problem]

[0011] Means of the Invention The present inventors have conducted extensive research to solve the above problems and have found that the following polyfunctional amine compound can achieve the above object, thereby completing the present invention. That is, the present invention relates to the following [1] to [3]. [1] An amine compound containing an isocyanurate ring, represented by the following general formula (I):

[0012] [ka]

[0013] (R1's are each independently the same or different hydrocarbons, and n is the number of repetitions and represents a real number of 0≦n<10.)

[0014] [2] The amine compound according to [1], wherein in the formula (I), R1 is one or more of the following general formula (II):

[0015] [ka] (The wavy line in the formula represents the bond to the nitrogen atom.)

[0016] [3] An amine precursor represented by the following formula (III):

[0017] [ka]

[0018] (R1's are each independently the same or different hydrocarbons, R2's are each a tertiary alcohol residue or a 4-substituted benzyl alcohol residue, and n is the number of repetitions and is a real number of 0≦n<10.) Effect of the Invention

[0019] INDUSTRIAL APPLICABILITY The amine compound containing an isocyanurate ring of the present invention has excellent low-temperature curing properties and excellent coloring and heat-resistant coloring properties, and is therefore useful as a curing agent for epoxy resins. [Brief description of the drawings]

[0020] [Figure 1] 1 shows a GPC chart of Example 1. [Diagram 2]1 shows the 1H-NMR chart of Example 1. [Diagram 3] 1 shows an IR spectrum of Example 1. [Figure 4] 1 shows a GPC chart of Example 2. [Diagram 5] 1H-NMR chart of Example 2 is shown. [Figure 6] 1 shows an IR spectrum of Example 2. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0021] Hereinafter, an embodiment for carrying out the present invention (hereinafter, referred to as "the present embodiment") will be described in detail. The following embodiment is an example for explaining the present invention, and is not intended to limit the present invention to the following content. The present invention can be carried out with appropriate modifications within the scope of its gist.

[0022] The amine compound containing an isocyanurate ring of the present invention has a structure represented by the following formula (I).

[0023] [ka]

[0024] (R1's are each independently the same or different hydrocarbons, and n is the number of repetitions and represents a real number of 0≦n<10.)

[0025] The polyfunctional amine compound having an isocyanurate ring can be synthesized by reacting a polyisocyanate having an isocyanurate ring with a specific alcohol compound to obtain a carbamate amine precursor represented by the following general formula (III), and then reacting the resulting amine precursor with an acid catalyst.

[0026] [ka]

[0027] (R1's are each independently the same or different hydrocarbons, and n is the number of repetitions and represents a real number of 0≦n<10.)

[0028] In the above formulas (I) and (II), R1 is preferably at least one of the following general formula (II).

[0029] [ka]

[0030] In formula (II), the wavy line represents the bond to the nitrogen atom.

[0031] From the viewpoints of availability, heat resistance, and solvent solubility, the compounds having the structures of (A-2), (A-3), and (A-7) are preferred.

[0032] In the formula (I), n represents a repeating unit and is a real number of 0≦n<10, preferably 0≦n<9, and more preferably 0≦n<8. If n is 10 or more, the solvent solubility and the compatibility with the resin may decrease.

[0033] In the carbamate reaction, the reaction can be carried out without a solvent or with a solvent. The solvent that can be used is not particularly limited, and examples thereof include non-water-soluble solvents such as aromatic solvents such as toluene and xylene, aliphatic solvents such as cyclohexane and n-hexane, ethers such as diethyl ether and diisopropyl ether, ester solvents such as ethyl acetate and butyl acetate, and ketone solvents such as methyl ethyl ketone, methyl isobutyl ketone, and cyclopentanone, but are not limited thereto, and two or more of them may be used in combination. In addition to the non-water-soluble solvent, aprotic polar solvents can also be used in combination. For example, dimethyl sulfone, dimethyl sulfoxide, dimethylformamide, dimethylacetamide, 1,3-dimethyl-2-imidazolidinone, N-methylpyrrolidone, etc. may be used in combination, and two or more of them may be used in combination.

[0034] The polyisocyanate having an isocyanurate ring is not particularly limited, and examples thereof include tetramethylene diisocyanate, 1,5-pentamethylene diisocyanate (PDI), 1,6-hexamethylene diisocyanate (HDI), dodecamethylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate (TMDI), lysine diisocyanate (LDI), 1,4-cyclohexane diisocyanate, isophorone diisocyanate (IPDI), trimethylhexamethylene diisocyanate, 4,4'-diphenylmethane diisocyanate (H12MDI), norbornene diisocyanate (NBDI), xylylene diisocyanate (XDI), and tetramethylxylylene diisocyanate. Examples of the polyisocyanate include polyisocyanates obtained by trimerizing, by a known method, one or more oligomeric polyisocyanates, such as tris(isocyanate phenyl)thiophosphate, ... From the viewpoints of availability, heat resistance, and solvent solubility, polyisocyanates obtained by trimerizing 1,5-pentamethylene diisocyanate (PDI), 1,6-hexamethylene diisocyanate (HDI), and isophorone diisocyanate (IPDI) are more preferred.

[0035] For the synthesis of the amine precursor of the carbamate, a tertiary alcohol compound, 4-substituted benzyl alcohol material can be used.

[0036] Examples of tertiary alcohols include tert-butanol, 1-methylcyclohexanol, 2-methyl-2-butanol, 2-methyl-2-pentanol, 3-quinuclidinyl benzilate, 3-methylpentanol, 2-methylisoborneol, 1-adamantanol, acetocyanohydrin, 1,3-adamantanediol, diacetone alcohol, triacetone alcohol, triphenylmethanol, etc. From the viewpoint of removing by-products, tert-butanol is more preferable.

[0037] As the 4-substituted benzyl alcohol, for example, a benzyl alcohol having a structure represented by the following general formula is preferable.

[0038] [ka]

[0039] In the formula, R4 is not particularly limited as long as it is an electron-withdrawing group, and examples thereof include alkoxy groups such as methoxy and ethoxy groups, hydroxyl groups, acetoxy groups, sulfonyl groups, formyl groups, nitro groups, azide groups, cyano groups, etc. A methoxy group is more preferable in terms of suppressing side reactions and facilitating purification.

[0040] The carbamate reaction can be carried out without a catalyst or with a known catalyst, which is not particularly limited and includes, for example, metal catalysts such as butyltin dilaurate (DBTL), bismuth neodecanoate, and zinc octanoate, and basic catalysts such as triethylamine (TEA), imidazole, diazabicyclooctane (DABCO), and tertiary amines.

[0041] The carbamate reaction can be carried out at a reaction temperature of 40° C. to 150° C., more preferably in the range of 60° C. to 120° C. If the reaction temperature is too low, the reaction time may be long, and if the reaction temperature is too high, the reacted carbamate moiety may decompose.

[0042] The method of obtaining an amine compound from the amine precursor will be described. The amine compound represented by the formula (I) can be obtained by using an acid catalyst for the amine precursor. The acid catalyst is not particularly limited, and may be hydrochloric acid, phosphoric acid, sulfuric acid, formic acid, p-toluenesulfonic acid, methanesulfonic acid, Lewis acids such as aluminum chloride and zinc chloride, activated clay, acidic clay, white carbon, zeolite, solid acids such as silica alumina, acidic ion exchange resins, etc. These may be used alone or in combination of two or more. The amount of the acid catalyst used is 0.01 to 10.0 mol, preferably 0.05 to 5.0 mol, relative to 1.0 mol of the amine group generated. If the amount of catalyst is too small, the amine precursor may remain, and if the amount of catalyst is too large, purification after the reaction may be difficult.

[0043] The reaction for obtaining an amine compound from the carbamate reaction may be carried out through a known purification step after each reaction, or may be carried out continuously in one pot without going through a purification step.

[0044] In the reaction to obtain an amine compound from the amine precursor, the reaction can be carried out without a solvent or with a solvent. The solvent that can be used is not particularly limited, and examples thereof include non-water-soluble solvents such as aromatic solvents such as toluene and xylene, aliphatic solvents such as cyclohexane and n-hexane, ethers such as diethyl ether and diisopropyl ether, ester solvents such as ethyl acetate and butyl acetate, and ketone solvents such as methyl ethyl ketone, methyl isobutyl ketone, and cyclopentanone, but are not limited thereto, and two or more of them may be used in combination. In addition to the non-water-soluble solvent, aprotic polar solvents can also be used in combination. For example, dimethyl sulfone, dimethyl sulfoxide, dimethylformamide, dimethylacetamide, 1,3-dimethyl-2-imidazolidinone, N-methylpyrrolidone, etc. may be used in combination, and two or more of them may be used in combination.

[0045] Depending on the application, it can be used in the form of an amine hydrochloride, or it can be used as an amine compound by washing with an aqueous solution or a basic aqueous solution. The basic aqueous solution is not particularly limited, but an aqueous solution of sodium hydroxide, sodium carbonate, or sodium hydrogen carbonate can be used.

[0046] The amine compound obtained from the amine precursor of the present invention has excellent low-temperature curing properties, heat resistance, and heat yellowing resistance as a curing agent for epoxy resins. It is suitable for use as a sealant for organic EL elements, a sealant for high-brightness LEDs, and optical device components such as solar cells. EXAMPLES

[0047] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to the following examples.

[0048] <Gel Permeation Chromatography (GPC)> The weight average molecular weight (Mw) and number average molecular weight (Mn) were calculated in terms of polystyrene using a polystyrene standard solution. GPC: HLC-8320GPC (Tosoh Corporation) Column: TSKgel SuperMultipreHZ-M Eluent: Tetrahydrofuran Column temperature: 40℃ Detection: RI (Differential Refractive Index Detector)

[0049] <Infrared absorption spectroscopy (IR)> Equipment: IRAffinity-1S (Shimadzu Corporation) <Amine value> The measurement was performed without using perchloric acid according to the method described in JIS K-7237, and the obtained value was taken as the amine equivalent in g / eq.

[0050] Example 1 Into a four-neck flask equipped with a stirrer, a thermometer, a condenser, and a nitrogen line were placed 208.0 g of toluene, 242.8 g of an isocyanurate modified product of isophorone diisocyanate (EVONIK's "VESTANAT T-1890 / 100", isocyanate group content 17.3% by mass), and 145.1 g (1.05 mol) of p-methoxybenzyl alcohol. The temperature was raised to 110°C while blowing nitrogen into the system, and the reaction was carried out at the same temperature for 10 hours. In the infrared spectrum, the characteristic absorption of the isocyanate group at 2250 cm was observed. -1 It was confirmed that the absorption of 1H had completely disappeared, and the amount of isocyanate calculated from titration according to JIS K6806 was 0. The obtained solution was washed five times with water, and the solvent was distilled off to obtain 350 g (92% yield) of a white solid amine precursor (1) (R1 is the above formula (A-7), n=0 in 70%, and n≧1 in 30% (according to the GPC chart in Figure 1)). The GPC chart of the obtained amine precursor is shown in Figure 1. The number average molecular weight Mn and weight average molecular weight Mw were 1232 and 1429, respectively, as determined by GPC analysis. It was confirmed that a compound had been produced from the IR spectrum and 1H-NMR. The 1H-NMR is shown in Figure 2, and the IR spectrum is shown in Figure 3. 150.0 g of toluene was added to 100.0 g of the obtained amine precursor (1), and 57.8 g of methanesulfonic acid was added dropwise for 1 hour, and then the reaction was carried out at 60°C for 1 hour. After cooling, an aqueous sodium hydroxide solution was added until the pH reached 8. The precipitated solid was dissolved in the organic layer and washed five times with water. The solvent was distilled off to obtain 60 g of amine compound (1). The amine equivalent of the obtained amine compound was 222 g / eq (theoretical value: amine equivalent 217).

[0051] Example 2 Into a four-neck flask equipped with a stirrer, a thermometer, a condenser, and a nitrogen line were added 34.05 g of toluene, 179.5 g of an isocyanurate modified product of hexamethylene diisocyanate ("Coronate HXLV" manufactured by Tosoh Corporation, isocyanate group content 23.4% by mass), 81.4 g (1.1 mol) of tertiary butanol, and 11.2 g (0.1 mol) of triethylenediamine. The temperature was raised to 90°C while blowing nitrogen into the system, and the reaction was carried out at the same temperature for 16 hours. In the infrared spectrum, the characteristic absorption of the isocyanate group at 2250 cm was observed. -1 It was confirmed that the absorption of 100.0 g had completely disappeared, and the amount of isocyanate calculated from titration according to JIS K6806 was 0. The obtained solution was washed five times with water, and the solvent was distilled off to obtain 221 g (87% yield) of a white solid amine precursor (2) (R1 is the above formula (A-3), n=0 in 70%, and n≧1 in 30% (according to the GPC chart in FIG. 4)). The GPC chart of the obtained amine precursor is shown in FIG. 4. The number average molecular weight Mn was 1200 and the weight average molecular weight Mw was 1436 by GPC analysis. 1H-NMR is shown in FIG. 5, and the IR spectrum is shown in FIG. 6. It was confirmed that a compound was produced from the IR spectrum and 1H-NMR. 150.0 g of toluene was added to 100.0 g of the obtained amine precursor (2), and 54.3 g of methanesulfonic acid was added dropwise for 1 hour, and then the reaction was carried out at 60° C. for 1 hour. After cooling, an aqueous sodium hydroxide solution was added until the pH reached 8. The precipitated solid was dissolved in the organic layer and washed five times with water. The solvent was distilled off to obtain 50 g of amine compound (2). The amine equivalent of the obtained amine compound was 160 g / eq (theoretical value: amine equivalent 153).

[0052] Reference example 3 A four-neck flask equipped with a stirrer, a thermometer, a condenser, and a nitrogen line was charged with 65.4 g of toluene, 65.4 g of N-methylpyrrolidone, 179.5 g of an isocyanurate modified product of hexamethylene diisocyanate (Tosoh Corporation's "Coronate HXLV" isocyanate group content 23.4% by mass), and 93.6 g of 35% hydrochloric acid. The temperature was raised to 60°C while blowing nitrogen into the system, and the reaction was carried out at the same temperature, resulting in the precipitation of a gel-like solid substance.

[0053] Examples 3 to 4, Comparative Example 1 The amine compounds (1) and (2) obtained above, and the amine compound represented by the following formula, were blended under the blending conditions shown in the table to prepare a resin liquid.

[0054] [Table 1]

[0055] Amine chemical (3) Amine compound represented by the following formula (amine equivalent: 202 g / eq)

[0056] [ka]

[0057] <Curability> Each resin liquid was heated on a hot plate at 100° C., and the time until it lost its fluidity was measured. Less than 60 minutes was evaluated as ◯, and 60 minutes or more was evaluated as ×. <Transmittance, heat-resistant transmittance> Each resin liquid was poured into a 1 mm thick Teflon (registered trademark) mold and cured for 2 hours at 100° C., 2 hours at 120° C., and 3 hours at 180° C. The light transmittance of the cured resin was measured under the following conditions. Measurement equipment: Spectrophotometer U-3900H (Hitachi High-Tech Science) Measurement wavelength range: 300nm~800nm The transmittance at 400 nm of the obtained cured product and the transmittance at 400 nm after 1 hour at 230° C. were measured. A 400 nm transmittance of 60% or more was evaluated as ◯, and a transmittance of less than 60% was evaluated as x.

[0058] [Table 2]

[0059] From the above results, it was found that the amine compound of the present invention is excellent in low-temperature curing property, transmittance (coloration) and heat-resistant transmittance (heat-resistant coloration). Therefore, the amine compound of the present invention is useful as a curing agent for epoxy resins.

Claims

1. A polyfunctional amine compound having an isocyanurate ring and represented by the following general formula (I): 【Chemistry 1】 (In formula (I), R １ are each independently the same or different hydrocarbons, and n is the number of repetitions and represents a real number of 0≦n<10.

2. In the formula (I), R １ The polyfunctional amine compound according to claim 1, wherein the polyfunctional amine compound is one or more of the following general formula (II): 【Chemistry 2】 (The wavy line in formula (II) is the bonding site with the nitrogen atom.)

3. An amine precursor represented by the following formula (III): 【Chemistry 3】 (In formula (II), R １ are each independently the same or different hydrocarbons, R ２ represents a tertiary alcohol residue or a 4-substituted benzyl alcohol residue; n is the number of repetitions and is a real number in the range of 0≦n<10.

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