JP2006321834A - Curing agent for urethane resin - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a low-toxicity curing agent for urethane resin having short curing time of an urethane prepolymer and having good productivity, compared with a case where 3,3'-dichloro-4,4'-diaminodiphenylmethane (MOCA) is used and having physical properties of the cured product which is equivalent to or better than those obtained when using MOCA. <P>SOLUTION: The curing agent for urethane resin is composed of an aminophenol compound represented by general formula (I) (wherein R<SP>1</SP>to R<SP>4</SP>are each independently a hydrogen atom or a 1-20C alkyl group; A is a direct bond, -O-, -NH-, -SO<SB>2</SB>-, -CH<SB>2</SB>- or -C(CH<SB>3</SB>)<SB>2</SB>- and OH group and NH<SB>2</SB>group in one benzene ring exist at adjacent position; k is 0 or 1; m and n are each 1 or 2). <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a curing agent for urethane resin, and more specifically, since it has a hydroxyl group in the molecule, it has low toxicity, can freely change the curing rate, and is suitable as a curing agent for RIM (reaction injection molding). Relates to a curing agent for urethane resin.

Polyurethane resins are widely used in the fields of coating materials, sealing materials, adhesives, etc. due to their excellent flexibility and durability. For example, they are widely used as coating materials in waterproofing materials, flooring materials, etc. in use.
In general, a polyurethane resin is a urethane prepolymer obtained by reacting a relatively high molecular weight polyol having an OH group at the terminal with an excess of an organic polyisocyanate.

3,3′-dichloro-4,4′-diaminodiphenylmethane (hereinafter referred to as “MOCA”) and other blending components are blended to form a urethane composition, and this urethane composition is heated and reacted to form a urethane prepolymer. Is produced by chain extension.
However, this MOCA is suspected of being a carcinogen and is a chlorinated compound, so it is harmful to the human body and the environment because it may induce dioxins, which are extremely toxic when incinerated, and generate acid gas. It has been pointed out as a substance.
Further, when MOCA is used as a curing agent, it takes a long time for curing, and thus there are problems such as poor productivity. Therefore, when an attempt is made to shorten the curing time by using an appropriately prepared catalyst or the like, the curing time is shortened, but when the curing agent is blended with the urethane prepolymer, the viscosity tends to be accelerated. For this reason, there are problems such as poor mixing of the blending components and clogging of the piping of the casting machine, and further failure to cast into the mold.
Although it has been proposed to use an aromatic diamine compound such as diethyltoluenediamine as an alternative to MOCA, it does not completely solve the toxicity of chlorine, although it does not contain chlorine. In addition, diethyltoluenediamine has an extremely high reactivity, and thus has a problem that it is difficult to control.

In the case of using a low-reactivity MOCA substitute for the production of polyurethane resin, a method using a catalyst such as organometallic lead has been used so far, but this causes a decrease in heat resistance of the polyurethane resin. It was. Recently, as a method for improving curability, a method in which diaminodiphenylmethanes are used in combination with diethyltoluenediamine or a secondary amine (see, for example, Patent Documents 1 and 2), a polyoxyalkylene polyol having a low degree of unsaturation, and diethyldiaminotoluene are used. A method of combining a curing agent component containing and an isocyanate component containing an isocyanate group-terminated polyurethane prepolymer obtained by reacting a high molecular weight polyol and a polyisocyanate compound (for example, see Patent Document 3) has been disclosed. There is a problem that the balance between curability and workability is poor.
As a method for avoiding the toxicity that MOCA has, a method using methylthiotoluenediamine and an acid catalyst as main components as a curing agent (see, for example, Patent Document 4), and 4-methyl-2,6-bis (methylthio) as a curing agent. ) -1,3-benzenediamine and 2-methyl-4,6-bis (methylthio) -1,3-benzenediamine are used (for example, see Patent Document 5), but a third substance is added. Or a complicated compound must be used, and it is difficult to say from the viewpoint of cost.

JP 09-316153 A JP-A-10-195163 JP-A-10-130360 JP 2000-1920203 A JP 2001-226446 A

  The present invention has been made in view of the above circumstances, is safer for the human body than MOCA, is more environmentally friendly, has a shorter curing time of urethane prepolymer than MOCA, and has good productivity. An object of the present invention is to provide a low-toxic curing agent for urethane resin having a cured product physical property equivalent to or higher than that of a cured product.

As a result of extensive research, the present inventor has found that a specific aminophenol compound in which an NH ₂ group and an OH group are adjacent to each other in one benzene ring is easy to desorb hydrogen and has high reactivity, and is also present in the molecule. It was found to have low toxicity because it has an OH group. In general, aminophenol compounds have a very high reactivity, but it has been found that the reactivity can be controlled by N-alkylation. In general, urethane curing agents are required to have optimum reactivity depending on the application. For use in urethane resins that require relatively low reactivity, a balance between working time and curing time is required. Also found to be good. The present invention has been completed based on such findings.
That is, the present invention provides the following curing agent for urethane resin.
1. The following general formula (I)

(In the formula, R ^{1 to} R ⁴ each independently represent a hydrogen atom or an alkyl group having 1 to 20 carbon atoms, and A represents a direct bond, —O—, —NH—, —SO ₂ —, —CH _2. -Or -C (CH ₃ ) _2-, and the OH group and the NH ₂ group in one benzene ring are present at adjacent positions, k is 0 or 1, and m and n are 1 or 2. )
A urethane resin curing agent comprising an aminophenol compound represented by the formula:
2. The aminophenol compound represented by the general formula (I) is 2,2-bis (3-amino-4-hydroxyphenyl) propane or 2,2-bis [3- (isopropylamino) -4-hydroxyphenyl] propane. 2,2-bis [3- (1-methylpropylamino) -4-hydroxyphenyl] propane, 2,2-bis [3- (1-methylpentylamino) -4-hydroxyphenyl] propane, 2,2 The curing agent for urethane resin according to 1 above, which is bis (3,5-diamino-4-hydroxyphenyl) propane or 2,6-diamino-4-methylphenol.

  According to the present invention, the curing agent for urethane resin is excellent in reactivity, has low toxicity as compared with the conventional curing agent MOCA, has improved curability, and has a good balance between working time and curing time. Can be provided.

  The curing agent for urethane resin of the present invention has the following general formula (I):

It is an aminophenol compound represented by these.
In the said general formula (I), R < ¹ > -R < ⁴ > shows a hydrogen atom or a C1-C20 alkyl group each independently. Here, the alkyl group having 1 to 20 carbon atoms of R ^{1 to} R ⁴ may be linear, branched or cyclic, and examples thereof include a methyl group, an ethyl group, and an n-propyl group. , Isopropyl, various butyl, various pentyl, various hexyl, various octyl, various decyl, various dodecyl, various tetradecyl, various hexadecyl, various octadecyl, various icosyl, cyclopentyl, cyclohexyl, Examples thereof include a methylcyclohexyl group, a cyclopentylmethyl group, and a cyclohexylmethyl group. Among these, a C1-C10 alkyl group is preferable.
A represents a direct bond, —O—, —NH—, —SO ₂ —, —CH ₂ — or —C (CH ₃ ) ₂ —, and the OH group and NH ₂ group in one benzene ring are adjacent to each other. Exists. k is 0 or 1, and m and n are 1 or 2.

Among the aminophenol compounds represented by the above general formula (I), those having k = 0 are
2-amino-3-methylphenol, 2,6-diamino-3-methylphenol, 2-amino-4-methylphenol, 2,6-diamino-4-methylphenol, 2-isopropylamino-3-methylphenol, Examples include 2,6-diisopropylamino-3-methylphenol, 2-isopropylamino-4-methylphenol and 2,6-diisopropylamino-4-methylphenol.
Among the aminophenol compounds represented by the above general formula (I), those in which k is 1 are preferably those in which A is —C (CH ₃ ) ₂ —, in which m and n are 1. 2,2-bis (3-amino-4-hydroxyphenyl) propane, 2,2-bis [3- (methylamino) -4-hydroxyphenyl] propane, 2,2-bis [3- (ethyl) Amino) -4-hydroxyphenyl] propane, 2,2-bis [3- (isopropylamino) -4-hydroxyphenyl] propane, 2,2-bis [3- (1-methylpropylamino) -4-hydroxyphenyl Propane and 2,2-bis [3- (1-methylpentylamino) -4-hydroxyphenyl] propane.

In addition, examples in which A is —C (CH ₃ ) ₂ —, k is 1, m, and n are 2, include 2,2-bis (3,5-diamino-4-hydroxyphenyl) propane, 2,2 -Bis (3,5-dimethylamino-4-hydroxyphenyl) propane, 2,2-bis (3,5-diethylamino-4-hydroxyphenyl) propane, 2,2-bis (3,5-diisopropylamino-4) -Hydroxyphenyl) propane, 2,2-bis [3,5-di (1-methylpropylamino) 4-hydroxyphenyl] propane and 2,2-bis [3,5-di (1-methylpentyl) amino- 4-hydroxyphenyl] propane and the like.
Among these, in the present invention, 2,2-bis (3-amino-4-hydroxyphenyl) propane, 2,2-bis [3- (isopropylamino) -4-hydroxyphenyl] propane, 2,2- Bis [3- (1-methylpropylamino) -4-hydroxyphenyl] propane, 2,2-bis [3- (1-methylpentylamino) -4-hydroxyphenyl] propane, 2,2-bis (3 5-Diamino-4-hydroxyphenyl) propane and 2,6-diamino-4-methylphenol are preferred.

  Among the aminophenol compounds represented by the above general formula (I), 2,2-bis (3-amino-4-hydroxyphenyl) propane can be produced, for example, by the following method. That is, in a suitable solvent that is inert to the nitration reaction, such as methyl ethyl ketone, bisphenol A is usually -30 to 30 ° C, preferably 0 ° C to room temperature, with a nitrating agent such as nitric acid. Nitration is performed for about 1 to 10 hours to obtain a dinitro form of bisphenol A. In this nitration reaction, since the hydroxyl group is an electron donating group, the nitro group is usually introduced at the o-position and the p-position with respect to the hydroxyl group. Therefore, when A which is a divalent group is bonded to the hydroxyl group at the p-position, an o-nitrophenol compound can be obtained with a particularly high selectivity.

Next, this nitrophenol compound is reduced with a reducing agent such as hydrogen gas in the presence of a reduction catalyst in a suitable solvent such as dimethylformamide. As the reduction catalyst, for example, a catalyst in which a metal catalyst such as palladium / carbon, nickel, or platinum is supported on alumina, silica gel, zeolite, or the like can be used. The reduction treatment is usually performed at a temperature of about room temperature to about 150 ° C. for about 1 to 20 hours under a pressure of 0.1 to 10 MPa. In this way, 2,2-bis (3-amino-4-hydroxyphenyl) propane is obtained.
2,2-bis (3-alkylamino-4-hydroxyphenyl) propane can be obtained by a reaction in which the amino group of 2,2-bis (3-amino-4-hydroxyphenyl) propane is substituted with an alkylamino group. it can.

  The curing agent for urethane resin of the present invention can be used in combination with a conventionally known curing agent for urethane resin as long as the object of the present invention is not impaired. As this conventionally well-known hardening | curing agent for urethane resins, diethyl toluenediamine, methylbis (methylthio) benzenediamine, etc. are mentioned, for example. Further, as a curing accelerator, in polyurethane chemistry, metal salts composed of organic acids such as tin octoate, tin naphthenate, dibutyltin dilaurate, and zinc octoate and Sn, Co, Ni, Fe, Zn, Pb, triethylamine, Dimethylcyclohexylamine, 1,4-diazabicyclo [2.2.2] octane, 1,5-diazabicyclo [4.3.0] non-5-ene, 1,8-diazabicyclo [5.4.0] undeca- Tertiary amines such as 7-ene and diethylbenzylamine can be used in combination.

The urethane resin curing agent of the present invention can be used in the form of a masterbatch by mixing with a urethane resin such as an isocyanate-terminated prepolymer or a compound to be reacted with this urethane resin. Content of the hardening | curing agent for urethane resins of this invention in a masterbatch can be about 3-50 mass% normally in a masterbatch.
Using the curing agent for urethane resin of the present invention, a polyurethane compound can be obtained by reacting an isocyanate-terminated prepolymer with a polyol, and a polyamine compound is obtained by reacting the isocyanate-terminated prepolymer with an amide. be able to.

EXAMPLES Next, although an Example demonstrates this invention further in detail, this invention is not limited at all by these examples.
Example 1
(1) Synthesis of 2,2-bis (3-amino-4-hydroxyphenyl) propane (NH-1) In a three-necked flask with an internal volume of 1 L, 500 ml of methyl ethyl ketone (MEK) and 150 g of bisphenol A (BPA) ( 0.66 mol) was added, and the mixture was cooled in an ice bath so that the temperature was 5 ° C. or lower while stirring. After confirming that the internal temperature became 5 ° C. or less, dropping of 60 mass% nitric acid was started, and a total amount of 152 g of nitric acid was dropped. Nitric acid was dropped while adjusting the dropping speed so as to keep the temperature at 6-7 ° C. or lower.
After completion of the dropwise addition of nitric acid, the mixture was stirred for about 20 minutes, 45 ml of water was added, and saturated water of sodium hydrogencarbonate was added until the system reached pH 8 or higher. The aqueous phase was then separated and the aqueous phase was washed. Washing was performed by placing 150 ml of water in a separatory funnel and repeating this twice. The separated oil phase was dried and then MEK was concentrated by an evaporator to obtain a solid dinitro form of BPA (2,2-bis (3-nitro-4-hydroxyphenyl) propane).
Next, the dinitro form of BPA was reductively aminated by the following method. That is, 200 g of BPA dinitro compound, 3.2 g of 5 mass% Pd / C and 1000 ml of dimethylformamide (DMF) were charged in an autoclave having an internal volume of 2 L, and the reaction was continued under conditions of hydrogen pressure of 0.8 MPa and 80 ° C. until hydrogen absorption disappeared. DMF solution was obtained.
After the reaction is completed, the catalyst is filtered off, and the DMF solution is poured into 1500 ml of water that is being stirred in a flask having an internal volume of 2 L under nitrogen bubbling. It was. The precipitated solid was filtered off and dried to obtain 2,2-bis (3-amino-4-hydroxyphenyl) propane (NH-1) represented by the following formula (yield 73%).

This 2,2-bis (3-amino-4-hydroxyphenyl) propane was identified by ¹ H-NMR (measurement frequency 495.1 MHz) and ¹³ C-NMR (measurement frequency 124.5 MHz) (measuring instrument: Japan). (Electronic Co., Ltd., ECA-500). The measurement frequency and measuring instrument are the same in the following. FIG. 1 shows a ¹ H-NMR chart, and FIG. 2 shows a ¹³ C-NMR chart. The peak assignments are shown below.

¹ H-NMR d-DMSO (ppm)
(1) 1.42 (s) 6H, CH ₃ : (2) 4.30 (s) 4H, NH ₂ : (3) 6.27 (d) 2H, AROM-H: (4) 6.42 (s), 2H, AROM-H :
(5) 6.50 (d) 2H, AROM-H: (6) 8.63 (s) 2H, OH

¹³ C-NMR d-DMSO (ppm)
(1) 31.6, CH ₃ : (2) 41.5, 4th class: (4) 114.0, AROM-CH: (7) 114.1, AROM-CH:
(8) 114.8, AROM-CH: (5) 136.1, AROM-C: (3) 142.2, AROM-C: (6) 142.8, AROM-C

(2) Synthesis of polyamine compound The synthesized NH-1 was dissolved in methoxy N, N′-dimethylpropionamide (Fw (molecular weight) = 131, manufactured by Idemitsu Kosan Co., Ltd.), and the NH-1 content was 20 mass. % Liquid curing agent masterbatch was prepared. Next, an isocyanate-modified prepolymer (urethane resin, trade name MC-50, manufactured by Idemitsu Kosan Co., Ltd.) and the master batch were mixed to obtain a resin mixture. The amount of the master batch used (converted to the amount of NH-1) is that -NCO / curing agent active hydrogen equivalent (active hydrogen: total amount of active hydrogen of hydroxyl group, amino group) of the isocyanate-modified prepolymer and NH-1. The amount was 1.0. Next, the resin mixture was poured into a 150 × 300 × 2 mm mold at room temperature, pressed and cured, and then post-cured at 120 ° C. for 1 hour to obtain a sheet. The following evaluation was performed on this sheet and the like. The results are shown in Table 1.

(1) Tensile strength, 100% modulus (100M) and elongation As a sample, the sheet was cut into a rubber dumbbell piece (dumbbell No. 3). In accordance with JIS K6251-2004, a tensile test was performed using a tensile tester (Orientec Co., Ltd., Tensilon RTC-1325A) under the conditions of a tensile speed of 500 mm / min, and tensile strength, 100% modulus and elongation were measured. It was measured.
(2) Hardness Based on JIS K6253-1997, type A durometer hardness was measured using an automatic hardness meter (P1 manufactured by Asker Co., Ltd.).
(3) Pot life The time from the start of the resin mixture injection to the mold until the resin mixture gelled was measured.
(4) Possibility of dioxin generation Estimated from the structural formula of the curing agent.

Example 2
(1) Synthesis of 2,2-bis [3- (isopropylamino) -4-hydroxyphenyl] propane (NH-2) 2,2-bis (3-amino-4-hydroxyphenyl) obtained in Example 1 12 g (109.92 mmol) of propane, 100 ml (79 g, 1.4 mol) of acetone, 0.6 g of 5% by mass Pd / C and 30 g of MgSO ₄ were charged into an autoclave having an internal volume of 300 ml, and at 100 ° C. under a hydrogen pressure of 1.0 MPa. Stir. After 1 hour, hydrogen absorption stopped and the reaction was completed.
Pd / C and MgSO ₄ were removed from the reaction solution by suction filtration, the filtrate was concentrated, water was added to precipitate the product, this was dried, and 2,2-bis represented by the following formula: [3- (Isopropylamino) -4-hydroxyphenyl] propane (NH-2) was obtained (yield 93%).

This 2,2-bis [3- (isopropylamino) -4-hydroxyphenyl] propane was identified by ¹ H-NMR and ¹³ C-NMR. FIG. 3 shows a ¹ H-NMR chart, and FIG. 4 shows a ¹³ C-NMR chart. The peak assignments are shown below.

¹ H-NMR d-DMSO (ppm)
(2) 1.05 (d) 12H, CH ₃ : (1) 1.52 (s) 6H, CH ₃ : (3) 3.37 (m) 2H, CH: (4) 3.95 (d) 2H, NH ₂ :
(5) 6.27 (d) 2H, AROM-H: (6) 6.29 (s) 2H, AROM-H: (7) 6.51 (d) 2H, AROM-H: (8) 8.86 (s) 2H, OH

¹³ C-NMR d-DMSO (ppm)
(3) 22.5, CH ₃ : (1) 30.9, CH ₃ : (2) 41.3, 4th class: (4) 43.1, CH: (6) 109.8, AROM-CH:
(9) 112.7, AROM-CH: (10) 113.2, AROM-CH: (7) 135.4, AROM-C: (5) 141.7, AROM-C:
(8) 142.1, AROM-C

(2) Synthesis of polyamine compound In Example 1 (2), a polyamine compound was synthesized in the same manner except that NH-2 was used instead of NH-1, and the same evaluation was performed. The results are shown in Table 1.

Example 3
(1) Synthesis of 2,2-bis (3,5-diamino-4-hydroxyphenyl) propane (NH-3) In Example (1), 2 instead of 150 g (0.66 mol) of bisphenol A (BPA) , 2-bis (3-amino-4-hydroxyphenyl) propane (NH-1) 171 g (0.66 mol) was used to obtain a nitro form of NH-1. Next, a reductive amination reaction was carried out in the same manner as in Example (1) except that 220 g of this NH-1 nitro compound was used instead of 200 g of the dinitro compound of BPA, and 2,2- Bis (3,5-diamino-4-hydroxyphenyl) propane (NH-3) was obtained (yield 58%).

This 2,2-bis (3,5-diamino-4-hydroxyphenyl) propane was identified by ¹ H-NMR and ¹³ C-NMR. Peak assignments are shown below.

¹ H-NMR d-DMSO (ppm)
(1) 1.67 (s) 6H, CH ₃ : (2) 4.30 (s) 8H, NH ₂ : (3) 5.80 (s) 4H, AROM-H: (4) 8.63 (s) 2H, OH

¹³ C-NMR d-DMSO (ppm)
(1) 31.6, CH ₃ : (2) 41.5, 4th class: (4) (8) 106.4, AROM-CH: (6) 128.0, AROM-C:
(5) (7) 135.2, AROM-C: (3) 137.2, AROM-H:

(2) Synthesis of polyamine compound In Example 1 (2), a polyamine compound was synthesized in the same manner except that NH-3 was used instead of NH-1, and the same evaluation was performed. The results are shown in Table 1.

Example 4
(1) Synthesis of 2,2-bis [3- (1-methylpropylamino) -4-hydroxyphenyl] propane (NH-4) In Example 2, except that methyl ethyl ketone (MEK) was used instead of acetone. Similarly, 2,2-bis [3- (1-methylpropylamino) -4-hydroxyphenyl] propane (NH-4) represented by the following formula was synthesized (yield 91%).

This 2,2-bis [3- (1-methylpropylamino) -4-hydroxyphenyl] propane was identified by ¹ H-NMR and ¹³ C-NMR. FIG. 5 shows a ¹ H-NMR chart, and FIG. 6 shows a ¹³ C-NMR chart. The peak assignments are shown below.

¹ H-NMR d-DMSO (ppm)
(1) 0.79 (t) 6H, CH ₃ : (2) 1.00 (d) 6H, CH ₃ : (3) 1.47 (m) 4H, CH ₂ : (5) 1.47 (s) 4H, CH ₃ :
(4) 3.15 (m) 2H, CH: (6) 3.95 (s) 2H, NH: (7) 6.27 (s) 2H, AROM-H: (8) 6.29 (d) 2H, AROM-H:
(9) 6.51 (d) 2H, AROM-H: (10) 8.86 (s) 2H, OH

¹³ C-NMR d-DMSO (ppm)
(3) 10.1, CH ₃ : (6) 19.8, CH ₃ : (1) 28.7, CH ₃ : (4) 30.9, CH ₂ : (2) 41.3, Class 4: (5) 48.7, CH:
(8) 109.8, AROM-CH: (11) 112.7, AROM-CH: (12) 113.0, AROM-CH: (9) 135.4, AROM-C:
(7) 141.7, AROM-C: (10) 142.1, AROM-C

(2) Synthesis of polyamine compound In Example 1 (2), a polyamine compound was synthesized in the same manner except that NH-4 was used instead of NH-1, and the same evaluation was performed. The results are shown in Table 1.

Example 5
In Example 2, 2,2-bis [3- (1-methylpentylamino) -4-hydroxyphenyl represented by the following formula was used except that methyl isobutyl ketone (MIBK) was used instead of acetone. Propane (NH-5) was synthesized (yield 89%).

This 2,2-bis [3- (1-methylpentylamino) -4-hydroxyphenyl] propane was identified by ¹ H-NMR and ¹³ C-NMR. FIG. 7 shows a ¹ H-NMR chart, and FIG. 8 shows a ¹³ C-NMR chart. The peak assignments are shown below.

¹ H-NMR d-DMSO (ppm)
(1) 0.78 (t) 6H, CH ₃ : (2) 0.82 (d) 6H, CH ₃ : (4) 1.05 (m) 4H, CH ₂ : (3) 1.36 (m) 4H, CH ₂ :
(7) 1.51 (s) 6H , CH 3: (5) 1.59 (m) 4H, CH 2: (6) 3.26 (m) 2H, CH: (8) 3.89 (s) 2H, NH:
(9) 6.27 (s) 2H, AROM-H: (10) 6.29 (d) 2H, AROM-H: (11) 6.51 (d) 2H, AROM-H:
(12) 8.86 (s) 2H, OH

¹³ C-NMR d-DMSO (ppm)
(3) 21.3, CH ₃ : (8) 22.7, CH ₃ : (4) 22.8, CH ₂ : (5) 24.4, CH ₂ : (1) 28.7, CH ₃ : (6) 31.2, CH ₂ : (2 41.3, 4th grade:
(7) 48.9, CH: (10) 109.8, AROM-CH: (13) 112.7, AROM-CH: (14) 113.0, AROM-CH:
(11) 135.4, AROM-C: (9) 141.7, AROM-C: (12) 142.1, AROM-C

(2) Synthesis of polyamine compound In Example 1 (2), a polyamine compound was synthesized in the same manner except that NH-5 was used instead of NH-1, and the same evaluation was performed. The results are shown in Table 1.

Example 6
In Example 1 (2), 2,6-diamino-4-methylphenol (NH-6) represented by the following formula instead of NH-1 (trade name: 2,6 manufactured by Wako Pure Chemical Industries, Ltd.) A polyamine compound was synthesized in the same manner except that -dimethylphenol was used, and the same evaluation was performed. The results are shown in Table 1.

Comparative Example 1
In Example 1 (2), a polyamine compound was synthesized in the same manner except that 3,3′-dichloro-4,4′-diaminodiphenylmethane (MOCA) represented by the following formula was used instead of NH-1. Similar evaluations were made. The results are shown in Table 1.

  Since the urethane resin curing agent of the present invention is highly reactive, it is suitable for RIM (reactive injection molding) applications. In addition, since the urethane resin curing agent of the present invention has no carcinogenicity and does not generate dioxin upon combustion, (1) waterproofing material: paint film waterproofing material, sheet waterproofing material, spraying waterproofing material, (2) electrical insulation Material: Potting material, Casting material, Dipping material, Impregnating material, Dropping agent, Fluid immersion material, Hollow sealing material, (3) Adhesive: General adhesive, Adhesive tape, Insulating tape, Piping patch material, Shoes Adhesive for bottom, (4) Paint: General paint, heavy anti-corrosion paint, chipping-resistant paint, pool paint, (5) Sealing material: Double window sealing material, window gap sealing material, finger joint Seal material, putty, (6) Roll material: Roll material for papermaking, Roll material for iron making, Roll material for OA, (7) Pavement material: Elastic block for paving, Rubber chip binder, (8) Cover material: Sliding golf shaft Stop, anti-slip of fishing rod, (9) flooring: party Board, (10) Resin modifier, (11) Asphalt modifier, (12) Base material for urethane elastomer: packing material, shoe sole, furniture slip, mudguard mat backing, car mat backing, rubber clay, mold It is suitably used in the production of rubber materials for removing, mannequin dolls, tile backing materials, wet body suits, no-punk tire materials, resin materials for tracks, and the like.

1 is a ¹ H-NMR chart of a polyamine compound obtained in Example 1. 2 is a ¹³ C-NMR chart of the polyamine compound obtained in Example 1. FIG. 2 is a ¹ H-NMR chart of a polyamine compound obtained in Example 2. FIG. 3 is a ¹³ C-NMR chart of the polyamine compound obtained in Example 2. FIG. 2 is a ¹ H-NMR chart of a polyamine compound obtained in Example 4. FIG. 3 is a ¹³ C-NMR chart of the polyamine compound obtained in Example 4. FIG. 2 is a ¹ H-NMR chart of a polyamine compound obtained in Example 5. FIG. 3 is a ¹³ C-NMR chart of the polyamine compound obtained in Example 5. FIG.

Claims (2)

The following general formula (I)

(In the formula, R ^{1 to} R ⁴ each independently represent a hydrogen atom or an alkyl group having 1 to 20 carbon atoms, and A represents a direct bond, —O—, —NH—, —SO ₂ —, —CH _2. -Or -C (CH ₃ ) _2-, and the OH group and the NH ₂ group in one benzene ring are present at adjacent positions, k is 0 or 1, and m and n are 1 or 2. )
A urethane resin curing agent comprising an aminophenol compound represented by the formula: The aminophenol compound represented by the general formula (I) is 2,2-bis (3-amino-4-hydroxyphenyl) propane or 2,2-bis [3- (isopropylamino) -4-hydroxyphenyl] propane. 2,2-bis [3- (1-methylpropylamino) -4-hydroxyphenyl] propane, 2,2-bis [3- (1-methylpentylamino) -4-hydroxyphenyl] propane, 2,2 The curing agent for urethane resin according to claim 1, which is -bis (3,5-diamino-4-hydroxyphenyl) propane or 2,6-diamino-4-methylphenol.

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