Isophorone diamine composition, preparation method thereof and epoxy resin composition

Abstract

The invention relates to an isophorone diamine composition, a preparation method of the isophorone diamine composition and an epoxy resin composition, and the isophorone diamine composition comprises 3-aminomethyl-3, 5, 5-trimethyl cyclohexylamine and 10 to 2000 ppm of an isomeride 4-aminomethyl-3, 5, 5-trimethyl cyclohexylamine. The epoxy resin composition prepared from the isophorone diamine composition provided by the invention has the advantages of strong mechanical properties and high toughness, and especially has significant application advantages in the field of manufacturing of wind turbine blades and automobile parts.

Description

Technical Field

[0001] The invention belongs to the field of curing agents, and in particular relates to an isophorone diamine composition and a preparation method thereof, and an epoxy resin composition. Background Art

[0002] Isophorone diamine is a common amine compound that can be combined with epoxy resin to prepare a curing agent. It is widely used in wind turbine blades, automotive parts and other fields.

[0003] The long-term harsh use environment and large-scale development of wind turbine blades have put forward higher requirements for epoxy resin compositions, especially requiring the mechanical strength and toughness of epoxy resins to be very outstanding. However, traditional epoxy resins have the problems of weak flexibility, high brittleness, and short service life in harsh environments and in the production of large blades. For example, Chinese patent CN117264584A describes the introduction of a condensed ring naphthalene structure into the epoxy main chain, which gives it excellent mechanical properties and heat resistance, but also increases the initial viscosity of the system, resulting in a slower curing speed; Chinese patent CN102329586B uses hyperbranched polyester to improve the impact strength of epoxy resin, but there is still a phenomenon of rapid heat release during the curing process. Summary of the invention

[0004] The object of the present invention is to provide an isophoronediamine composition and a preparation method thereof.

[0005] Another object of the present invention is to provide an epoxy resin composition comprising the isophoronediamine composition, wherein the epoxy resin composition has higher strength and toughness.

[0006] In order to obtain high-strength and high-toughness epoxy resin, the applicant found through research that the content of isomers in isophorone diamine curing agents has a certain influence on the toughness and strength of epoxy resins. When a certain amount of isomer 4-aminomethyl-3,5,5-trimethylcyclohexylamine exists in 3-aminomethyl-3,5,5-trimethylcyclohexylamine, it has a good effect on improving the mechanical properties of epoxy resins.

[0007] To achieve the above purpose, the technical solution adopted by the present invention is as follows:

[0008] The present invention provides an isophorone diamine composition, wherein the isophorone diamine composition comprises 3-aminomethyl-3,5,5-trimethylcyclohexylamine and 10-2000 ppm, preferably 50-500 ppm, of an isomer 4-aminomethyl-3,5,5-trimethylcyclohexylamine, wherein the structure of 4-aminomethyl-3,5,5-trimethylcyclohexylamine is shown in formula (1):

[0009]

[0010] Preferably, the mass content of 3-aminomethyl-3,5,5-trimethylcyclohexylamine in the isophoronediamine composition is 80% or more, preferably 90%-99.9%.

[0011] When the content of 4-aminomethyl-3,5,5-trimethylcyclohexylamine is controlled within the range described in the present invention, the effect is best, mainly because 4-aminomethyl-3,5,5-trimethylcyclohexylamine is more linear and symmetrical, and can make the epoxy resin composition form a denser structure, further improving the mechanical properties of the epoxy resin composition, meeting the needs of the fields of wind turbine blades and automotive parts.

[0012] The present invention also provides a method for preparing an isophorone diamine composition, the preparation method comprising:

[0013] 1) reacting a mixture of α-isophorone and β-isophorone with hydrocyanic acid to obtain an isophoronenitrile composition;

[0014] 2) The isophoronenitrile composition undergoes an imidization reaction with liquid ammonia, and then further hydrogenates to generate an isophoronediamine composition.

[0015] The reaction in step 1) is generally referred to as a cyanation process. Specifically, the cyanation conditions for preparing isophoronenitrile by reacting isophorone with hydrocyanic acid in the presence of a catalyst, which are well known in the art, can be used.

[0016] Preferably, in the mixture of the raw materials α-isophorone and β-isophorone, the content of β-isophorone accounts for 0.02-5% of the total mass of isophorone, preferably 0.1-2%.

[0017] Preferably, hydrocyanic acid gas is introduced into isophorone, and a catalyst is added, and then the above materials are quickly stirred and mixed to carry out a cyanation reaction, thereby obtaining an isophoronenitrile composition containing 4-cyano-3,5,5-trimethylcyclohexanone.

[0018] Preferably, the molar ratio of the total molar amount of the mixture of α-isophorone and β-isophorone to hydrocyanic acid is 0.8-1.0:1, preferably 0.9-1.0:1.

[0019] Preferably, the reaction temperature of the cyanidation process is above 100°C, preferably above 110°C;

[0020] Preferably, the reaction temperature of the cyanidation step is below 200°C, preferably below 190°C.

[0021] Preferably, the cyanidation process is carried out under normal pressure or pressurized conditions.

[0022] Preferably, the reaction force (gauge pressure) of the cyanidation process is greater than or equal to 0.01 MPaG and less than or equal to 0.5 MPaG.

[0023] Preferably, the reaction time of the cyanidation step is more than 0.5 h, preferably more than 1 h.

[0024] Preferably, the reaction time of the cyanidation step is less than 20 hours, preferably less than 18 hours.

[0025] Preferably, the catalyst used in the cyanidation step is an alkaline compound, preferably an alkali metal compound, more preferably lithium hydroxide, sodium hydroxide, etc.

[0026] As the hydrogenation process, specifically, a method well known in the art is used. Isophorone nitrile and ammonia undergo imidization reaction under the action of an imidization catalyst, and then enter a hydrogenation reactor to undergo a further hydrogenation reaction in the presence of a hydrogenation catalyst to prepare isophorone diamine. Since the raw material is an isophorone nitrile composition obtained by the above-mentioned cyanidation process, an isophorone diamine composition containing 4-aminomethyl-3,5,5-trimethylcyclohexylamine is obtained.

[0027] Preferably, the imidization catalyst is an acidic or amphoteric metal oxide, preferably activated alumina and / or titanium oxide.

[0028] Preferably, the imidization reaction process can be carried out in a solvent or without a solvent, and the preferred solvent is an alcohol, such as methanol.

[0029] Preferably, the hydrogenation reaction catalyst is a supported catalyst, the active component is preferably nickel-based and / or cobalt-based, and the carrier is preferably alumina, silicon dioxide, or the like.

[0030] In the present invention, the specific hydrogenation reaction conditions can be selected according to the common knowledge in the art, such as reference patent CN117069593A.

[0031] In the present invention, the obtained isophorone diamine reaction liquid needs to be separated and purified by distillation. Usually, low-boiling methanol, water and other low-boiling substances are first separated in a light-removal tower, and then the decyanated material enters another distillation tower to separate the isophorone diamine composition. The content of 4-aminomethyl-3,5,5-trimethylcyclohexylamine can also be adjusted by distillation separation, so as to obtain an isophorone diamine composition that meets the use requirements.

[0032] Preferably, the distillation is carried out in a distillation tower.

[0033] Preferably, the distillation tower is a packed distillation tower.

[0034] Preferably, the distillation tower has a theoretical plate number of 10 or more, preferably 15 or more.

[0035] Preferably, the number of theoretical plates of the distillation tower is 50 or less, preferably 45 or less.

[0036] Preferably, the top pressure of the light-removal tower when separating light components is above 10 kPaA, preferably above 15 kPaA.

[0037] Preferably, the top pressure of the light-removal tower when separating light components is below 30 kPaA, preferably below 25 kPaA.

[0038] Preferably, the top pressure of the distillation tower is above 0.1 kPaA, preferably above 0.3 kPaA.

[0039] Preferably, the top pressure of the distillation tower is 5.0 kPaA or less, preferably 3.0 kPaA or less.

[0040] Another aspect of the present invention provides an epoxy resin composition, wherein the epoxy resin composition comprises the following components in parts by weight:

[0041] Epoxy resin 50-120 parts, preferably 70-90 parts;

[0042] 5-50 parts of the isophorone diamine composition, preferably 25-40 parts;

[0043] 20-50 parts of diluent, preferably 30-40 parts;

[0044] Reaction aid 0.1-5 parts, preferably 0.5-2 parts.

[0045] The epoxy resin may be selected from one or more of bisphenol A epoxy resin, bisphenol F epoxy resin, bisphenol S epoxy resin and the like.

[0046] Preferably, the epoxy resin is selected from bisphenol A epoxy resin, such as one or more of E51 resin, E54 resin, and F170 resin.

[0047] The isophorone diamine composition is the isophorone diamine composition of the present invention. The diluent includes one or more of allyl glycidyl ether, butyl glycidyl ether, methacrylate glycidyl ether, etc.

[0048] The reaction aid comprises a free radical initiator and a free radical accelerator, and the mass ratio of the free radical initiator and the free radical accelerator is 1:0.1-1, preferably 1:0.2-0.8.

[0049] Preferably, the free radical initiator is selected from organic peroxides, azo initiators, preferably one or more of tert-butyl peroxy-2-ethylhexanoate, tert-butyl perbenzoate, dibenzoyl peroxide, and methyl ethyl ketone peroxide;

[0050] Preferably, the free radical accelerator is selected from organic metal salts and tertiary amines, preferably one or more of cobalt isooctanoate, potassium isooctanoate, copper isooctanoate, pentamethyldiethylenetriamine, N,N-dimethylaniline and N,N-dimethylcyclohexylamine.

[0051] The epoxy resin composition of the invention is prepared by mixing epoxy resin, isophorone diamine composition, diluent and reaction auxiliary agent, stirring, vacuum degassing and curing.

[0052] Wherein, the vacuum degassing conditions are: vacuum degree is 0.05-0.1Mpa, preferably 0.08-0.1Mpa, and temperature is 5-45°C, preferably 25-35°C.

[0053] The curing conditions are: pre-curing temperature 30-55°C, time 30-240min, preferably temperature 35-45°C, time 60-120min; post-curing temperature 60-100°C, time 30-240min, preferably temperature 70-85°C, time 60-120min.

[0054] The epoxy resin composition can be suitably applied to wind turbine blades and automobile parts.

[0055] Compared with the prior art, the present invention has the following beneficial effects:

[0056] The isophorone diamine composition provided by the present invention contains 10-2000 ppm of 4-aminomethyl-3,5,5-trimethylcyclohexylamine represented by formula (1). The epoxy resin composition prepared therefrom has excellent mechanical properties, among which tensile strength, impact strength and fracture toughness are outstanding. DETAILED DESCRIPTION

[0057] In order to better understand the technical solution of the present invention, the preparation method of the present invention is further explained below through more specific examples, but it does not constitute any limitation.

[0058] (I) The test method of the relevant test in the present invention is as follows:

[0059] 1. The content ratio of 3-aminomethyl-3,5,5-trimethylcyclohexylamine and 4-aminomethyl-3,5,5-trimethylcyclohexylamine in the isophorone diamine composition

[0060] GC purity test instrument: Agilent 7890, column: DB-5, FID detector, injection port temperature 260℃, detector temperature 300℃, carrier gas: nitrogen (10mL / min), split ratio 10:1, injection volume: 20ul. The initial temperature of the column box was 100℃, maintained for 0.5 minutes, heated to 160℃ at 15℃ / min, maintained for 1.5 minutes, heated to 260℃ at 20℃ / min, maintained for 9 minutes, and the area normalized content was tested.

[0061] 2. Content ratio of 3-nitrile-3,5,5-trimethylcyclohexanone and 4-nitrile-3,5,5-trimethylcyclohexanone in isophoronenitrile composition

[0062] The above-mentioned gas chromatography method was also used for analysis, and the area normalized content was tested.

[0063] 3. Tensile strength

[0064] Refer to ISO527-2 and use Instron universal tensile testing machine, model Instron5980.

[0065] 4. Impact strength

[0066] Refer to ISO-179, using Instron pendulum impact tester, model CEAST 9050

[0067] 5. Fracture toughness

[0068] Refer to ISO 15024:2001, and use MTS fracture toughness testing machine, model Landmark250.

[0069] (II) The relevant raw material information in the present invention is as follows:

[0070] α-Isophorone (α-IP), Wanhua Chemical Group Co., Ltd.

[0071] β-Isophorone (β-IP), Sigma

[0072] Hydrocyanic acid (HCN), Wanhua Chemical Group Co., Ltd.

[0073] Lithium hydroxide (LiOH), Beijing Inotech

[0074] Sodium hydroxide (NaOH), Beijing Inotech

[0075] Activated Alumina, Dalian Haixin

[0076] Loaded cobalt catalyst (supported by aluminum oxide), medium catalyst

[0077] Bisphenol A epoxy resin E51, E54 and F170, Nan Ya Epoxy Resin (Kunshan) Co., Ltd.

[0078] Glycidyl Methacrylate (GMA), Wanhua Chemical Group Co., Ltd.

[0079] N,N-Dimethylcyclohexylamine, Wanhua Chemical Group Co., Ltd.

[0080] Potassium 2-ethylhexanoate, Cobalt 2-ethylhexanoate, Copper 2-ethylhexanoate, Umicore International Ltd.

[0081] Tert-butyl peroxy-2-ethylhexanoate (TBPO), tert-butyl peroxybenzoate (TBPB), Lanzhou Additives Factory

[0082] It should be noted that, unless otherwise specified, "parts" and "%" are based on mass.

[0083] [Example 1]

[0084] The preparation method of the isophorone diamine composition is as follows:

[0085] 276 parts by mass of isophorone (including 0.055 parts by mass of β-IP and 275.045 parts by mass of α-IP) were added to the reaction kettle, and the mixture was stirred and heated to 100° C. while maintaining the system at normal pressure.

[0086] 67.5 parts by mass of hydrocyanic acid were pumped into an isophorone reactor, and 0.6 parts by mass of lithium hydroxide as a catalyst were added simultaneously. The addition was completed in 0.5 h, and the mixture was kept at 100° C. for 20 h. The catalyst was filtered out to obtain an isophorone nitrile composition.

[0087] The isophorone nitrile composition was subjected to imidization and hydrogenation reaction by the method in Example 1 of patent CN117069593A to obtain an isophorone diamine reaction solution.

[0088] The isophorone diamine reaction liquid is delighted in a light-removing tower, and light components such as methanol and water are taken out from the top of the tower. The delighted material then enters another distillation tower to take out the remaining light components from the top of the tower, and at the same time, the isophorone diamine composition is taken out from the tower. For the light-removing tower, it is filled with a filler equivalent to 15 theoretical plates; for the distillation tower for collecting the isophorone diamine composition, it is filled with a filler equivalent to 30 theoretical plates.

[0089] The conditions of the lightness removal tower are as follows:

[0090] Tower top pressure: 15.0kPaA

[0091] Tower top temperature: 65℃

[0092] Tower bottom temperature: 150℃

[0093] Average stay time: 2h

[0094] Thus, a crude isophorone diamine product after light removal is produced, which is then further distilled.

[0095] The conditions of the isophordione diamine composition distillation column are as follows:

[0096] Tower top pressure: 1.0kPaA

[0097] Tower top temperature: 125℃

[0098] Tower bottom temperature: 170℃

[0099] Average stay time: 3h

[0100] Thus, an isophoronediamine composition was prepared, wherein the content of 4-aminomethyl-3,5,5-trimethylcyclohexylamine in the composition was 10 ppm, and the mass content of 3-aminomethyl-3,5,5-trimethylcyclohexylamine was 99.80%.

[0101] [Example 2]

[0102] The preparation method of the isophorone diamine composition is as follows:

[0103] 276 parts by mass of isophorone (including 0.276 parts by mass of β-IP and 275.724 parts by mass of α-IP) were added to the reactor, stirred, heated to 110° C., and the system pressure was adjusted to 0.01 MPaG with nitrogen.

[0104] 60.0 parts by mass of hydrocyanic acid were pumped into an isophorone reactor, and 2.0 parts by mass of catalyst triethylamine were added simultaneously. The addition was completed in 0.5 h, and the mixture was kept at 110° C. for 18 h to obtain an isophorone nitrile composition.

[0105] The isophorone nitrile composition was subjected to imidization and hydrogenation reaction by the method in Example 1 of patent CN117069593A to obtain an isophorone diamine reaction solution.

[0106] The isophorone diamine reaction liquid is delighted in a light-removing distillation tower, and light components such as methanol and water are taken out from the tower top. The delighted material then enters another distillation tower to take out the remaining light components from the tower top, and at the same time, the isophorone diamine composition is taken out from the tower. For the light-removing tower, it is filled with a filler equivalent to 15 theoretical plates; for the distillation tower for collecting the isophorone diamine composition, it is filled with a filler equivalent to 30 theoretical plates.

[0107] The conditions of the lightness removal tower are as follows:

[0108] Tower top pressure: 15.0kPaA

[0109] Tower top temperature: 65℃

[0110] Tower bottom temperature: 150℃

[0111] Average stay time: 2h

[0112] Thus, a crude isophorone diamine product after light removal is produced, which is then further distilled.

[0113] The conditions of the isophordione diamine composition distillation column are as follows:

[0114] Tower top pressure: 1.0kPaA

[0115] Tower top temperature: 125℃

[0116] Tower bottom temperature: 170℃

[0117] Average stay time: 3h

[0118] Thus, an isophoronediamine composition was prepared, wherein the content of 4-aminomethyl-3,5,5-trimethylcyclohexylamine in the composition was 50 ppm.

[0119] [Example 3]

[0120] The preparation method of the isophorone diamine composition is as follows:

[0121] 276 parts by mass of isophorone (including 2.76 parts by mass of β-IP and 273.24 parts by mass of α-IP) were added to the reactor, stirred, heated to 150° C., and the system pressure was adjusted to 0.1 MPaG with nitrogen.

[0122] 54.0 parts by mass of hydrocyanic acid were pumped into an isophorone reactor, and 2.0 parts by mass of catalyst triethylamine were added simultaneously. The addition was completed in 0.5 h, and the mixture was kept at 150° C. for 10 h to obtain an isophorone nitrile composition.

[0123] The isophorone nitrile composition was subjected to imidization and hydrogenation reaction by the method in Example 1 of patent CN117069593 to obtain an isophorone diamine reaction solution.

[0124] The isophorone diamine reaction liquid needs to extract light components such as methanol and water at the top of the light removal tower. The material after light removal then enters another distillation tower to extract the remaining light components from the top of the tower, and at the same time, the isophorone diamine composition is extracted from the tower. For light removal, a filler equivalent to 15 theoretical plates is filled; for the distillation tower for collecting the isophorone diamine composition, a filler equivalent to 30 theoretical plates is filled.

[0125] The conditions of the lightness removal tower are as follows:

[0126] Tower top pressure: 15.0kPaA

[0127] Tower top temperature: 65℃

[0128] Tower bottom temperature: 150℃

[0129] Average stay time: 2h

[0130] Thus, a crude isophorone diamine product after light removal is produced, which is then further distilled.

[0131] The conditions of the isophordione diamine composition distillation column are as follows:

[0132] Tower top pressure: 1.0kPaA

[0133] Tower top temperature: 125℃

[0134] Tower bottom temperature: 170℃

[0135] Average stay time: 3h

[0136] Thus, an isophoronediamine composition was prepared, wherein the content of 4-aminomethyl-3,5,5-trimethylcyclohexylamine in the composition was 230 ppm.

[0137] [Example 4]

[0138] The preparation method of the isophorone diamine composition is as follows:

[0139] 276 parts by mass of isophorone (including 5.52 parts by mass of β-IP and 270.48 parts by mass of α-IP) were added to the reactor, stirred, heated to 190° C., and the system pressure was adjusted to 0.2 MPaG with nitrogen.

[0140] 54.0 parts by mass of hydrocyanic acid were pumped into an isophorone reaction kettle, and 2.0 parts by mass of catalyst triethylamine were added at the same time. The addition was completed in 0.5 h, and the mixture was kept at 190° C. for 1 h to obtain an isophorone nitrile composition.

[0141] The isophorone nitrile composition was subjected to imidization and hydrogenation reaction by the method in Example 1 of patent CN117069593A to obtain an isophorone diamine reaction solution.

[0142] The isophorone diamine reaction liquid is delighted in a light-removing tower, and light components such as methanol and water are taken out from the top of the tower. The delighted material then enters another distillation tower to take out the remaining light components from the top of the tower, and at the same time, the isophorone diamine composition is taken out from the tower. For the light-removing tower, it is filled with a filler equivalent to 15 theoretical plates; for the distillation tower for collecting the isophorone diamine composition, it is filled with a filler equivalent to 30 theoretical plates.

[0143] The conditions of the lightness removal tower are as follows:

[0144] Tower top pressure: 15.0kPaA

[0145] Tower top temperature: 65℃

[0146] Tower bottom temperature: 150℃

[0147] Average stay time: 2h

[0148] Thus, a crude isophorone diamine product after light removal is produced, which is then further distilled.

[0149] The conditions of the isophordione diamine composition distillation column are as follows:

[0150] Tower top pressure: 1.0kPaA

[0151] Tower top temperature: 125℃

[0152] Tower bottom temperature: 170℃

[0153] Average stay time: 3h

[0154] Thus, an isophoronediamine composition was prepared, wherein the content of 4-aminomethyl-3,5,5-trimethylcyclohexylamine in the composition was 500 ppm.

[0155] [Example 5]

[0156] The preparation method of the isophorone diamine composition is as follows:

[0157] 276 parts by mass of isophorone (including 13.8 parts by mass of β-IP and 262.2 parts by mass of α-IP) were added to the reactor, stirred, heated to 200° C., and the system pressure was adjusted to 0.5 MPaG with nitrogen.

[0158] 54.0 parts by mass of hydrocyanic acid were pumped into an isophorone reaction kettle, and 2.0 parts by mass of catalyst triethylamine were added at the same time. The addition was completed in 0.5 h, and the mixture was kept at 200° C. for 0.5 h to obtain an isophorone nitrile composition.

[0159] The isophorone nitrile composition was subjected to imidization and hydrogenation reaction by the method in Example 1 of patent CN117069593A to obtain an isophorone diamine reaction solution.

[0160] The isophorone diamine reaction liquid needs to be delightened in a light-removing tower, and light components such as methanol and water are taken out from the top of the tower. The delightened material then enters another distillation tower to take out the remaining light components from the top of the tower, and at the same time, the isophorone diamine composition is taken out from the tower. For the light-removing tower, it is filled with a filler equivalent to 15 theoretical plates; for the distillation tower for collecting the isophorone diamine composition, it is filled with a filler equivalent to 30 theoretical plates.

[0161] The conditions of the lightness removal tower are as follows:

[0162] Tower top pressure: 15.0kPaA

[0163] Tower top temperature: 65℃

[0164] Tower bottom temperature: 150℃

[0165] Average stay time: 2h

[0166] Thus, a crude isophorone diamine product after light removal is produced, which is then further distilled.

[0167] The conditions of the isophordione diamine composition distillation column are as follows:

[0168] Tower top pressure: 1.0kPaA

[0169] Tower top temperature: 125℃

[0170] Tower bottom temperature: 170℃

[0171] Average stay time: 3h

[0172] Thus, an isophoronediamine composition was prepared, wherein the content of 4-aminomethyl-3,5,5-trimethylcyclohexylamine in the composition was 1980 ppm.

[0173] [Comparative Example 1]

[0174] The preparation method of the isophorone diamine composition is as follows:

[0175] 276 parts by mass of isophorone (including 0.0276 parts by mass of β-IP and 275.9724 parts by mass of α-IP) were added to the reactor, stirred, heated to 150° C., and the system pressure was adjusted to 0.1 MPaG with nitrogen.

[0176] 54.0 parts by mass of hydrocyanic acid were pumped into an isophorone reactor, and 2.0 parts by mass of catalyst triethylamine were added simultaneously. The addition was completed in 0.5 h, and the mixture was kept at 150° C. for 10 h to obtain an isophorone nitrile composition.

[0177] The isophorone nitrile composition was subjected to imidization and hydrogenation reaction by the method in Example 1 of patent CN117069593A to obtain an isophorone diamine reaction solution.

[0178] The isophorone diamine reaction liquid is delighted in a light-removing tower, and light components such as methanol and water are taken out from the top of the tower. The delighted material then enters another distillation tower to take out the remaining light components from the top of the tower, and at the same time, the isophorone diamine composition is taken out from the tower. For the light-removing tower, it is filled with a filler equivalent to 15 theoretical plates; for the distillation tower for collecting the isophorone diamine composition, it is filled with a filler equivalent to 30 theoretical plates.

[0179] The conditions of the lightness removal tower are as follows:

[0180] Tower top pressure: 15.0kPaA

[0181] Tower top temperature: 65℃

[0182] Tower bottom temperature: 150℃

[0183] Average stay time: 2h

[0184] Thus, a crude isophorone diamine product after light removal is produced, which is then further distilled.

[0185] The conditions of the isophordione diamine composition distillation column are as follows:

[0186] Tower top pressure: 1.0kPaA

[0187] Tower top temperature: 125℃

[0188] Tower bottom temperature: 170℃

[0189] Average stay time: 3h

[0190] Thus, an isophoronediamine composition was prepared, wherein the content of 4-aminomethyl-3,5,5-trimethylcyclohexylamine in the composition was 6 ppm.

[0191] [Comparative Example 2]

[0192] The preparation method of the isophorone diamine composition is as follows:

[0193] 276 parts by mass of isophorone (including 16.56 parts by mass of β-IP and 259.44 parts by mass of α-IP) were added to the reactor, stirred, heated to 150° C., and the system pressure was adjusted to 0.1 MPaG with nitrogen.

[0194] 54.0 parts by mass of hydrocyanic acid were pumped into an isophorone reactor, and 2.0 parts by mass of catalyst triethylamine were added simultaneously. The addition was completed in 0.5 h, and the mixture was kept at 150° C. for 10 h to obtain an isophorone nitrile composition.

[0195] The isophorone nitrile composition was subjected to imidization and hydrogenation reaction by the method in Example 1 of patent CN117069593A to obtain an isophorone diamine reaction solution.

[0196] The isophorone diamine reaction liquid is delighted in a light-removing tower, and light components such as methanol and water are taken out from the top of the tower. The delighted material then enters another distillation tower to take out the remaining light components from the top of the tower, and at the same time, the isophorone diamine composition is taken out from the tower. For the light-removing tower, it is filled with a filler equivalent to 15 theoretical plates; for the distillation tower for collecting the isophorone diamine composition, it is filled with a filler equivalent to 30 theoretical plates.

[0197] The conditions of the lightness removal tower are as follows:

[0198] Tower top pressure: 15.0kPaA

[0199] Tower top temperature: 65℃

[0200] Tower bottom temperature: 150℃

[0201] Average stay time: 2h

[0202] Thus, a crude isophorone diamine product after light removal is produced, which is then further distilled.

[0203] The conditions of the isophordione diamine composition distillation column are as follows:

[0204] Tower top pressure: 1.0kPaA

[0205] Tower top temperature: 125℃

[0206] Tower bottom temperature: 170℃

[0207] Average stay time: 3h

[0208] Thus, an isophoronediamine composition was prepared, wherein the content of 4-aminomethyl-3,5,5-trimethylcyclohexylamine in the composition was 2500 ppm.

[0209] Application performance testing

[0210] The isophorone diamine compositions of the above examples and comparative examples were used to prepare epoxy resin compositions, and performance evaluation was performed after casting, as follows:

[0211] (1) Preparation method:

[0212] 75 g of epoxy resin (E51), 39 g of glycidyl methacrylate (GMA), 26 g of isophorone diamine composition (IPDA), 1 g of tert-butyl perbenzoate (TBPB), and 10 mg of N,N-dimethylcyclohexylamine were weighed separately, added into a 200 mL round-bottom flask, the composition was mixed evenly by mechanical stirring, and bubbles were removed by vacuum drying oven. The vacuum degree in the drying oven was 0.08 MPa and the temperature was 25° C. to obtain an epoxy resin composition.

[0213] The composition was poured into a sealed glass mold, heated and cured in a blast oven at 35° C. for 60 minutes, and then heated and cured at 90° C. for 120 minutes to obtain an epoxy resin composition casting.

[0214] (2) Performance evaluation:

[0215] The tensile strength, impact strength and fracture toughness of the epoxy resin composition casting were tested and the results are shown in Table 1.

[0216] Table 1. Performance test results of epoxy resin composition castings

[0217]

[0218] As can be seen from Table 1, the present invention can effectively improve the mechanical properties of the epoxy resin composition by controlling the content of 4-aminomethyl-3,5,5-trimethylcyclohexylamine in the isophoronediamine composition within 10-2000 ppm.

Claims

1. An isophorone diamine composition, characterized in that The isophorone diamine composition comprises 3-aminomethyl-3,5,5-trimethylcyclohexylamine and 10-2000 ppm, preferably 50-500 ppm, of the isomer 4-aminomethyl-3,5,5-trimethylcyclohexylamine. The structure of 4-aminomethyl-3,5,5-trimethylcyclohexylamine is shown in formula (1):

2. The composition according to claim 1, characterized in that The mass content of 3-aminomethyl-3,5,5-trimethylcyclohexylamine in the isophoronediamine composition is more than 80%, preferably 90%-99.9%.

3. A method for preparing an isophorone diamine composition, characterized in that: The preparation method comprises: 1) reacting a mixture of α-isophorone and β-isophorone with hydrocyanic acid to obtain an isophoronenitrile composition; 2) The isophoronenitrile composition undergoes an imidization reaction with liquid ammonia, and then further hydrogenates to generate an isophoronediamine composition.

4. The preparation method according to claim 3, characterized in that: In the mixture of raw materials α-isophorone and β-isophorone, the content of β-isophorone accounts for 0.02-5% of the total mass of isophorone, preferably 0.1-2%.

5. The preparation method according to claim 3 or 4, characterized in that: Passing hydrocyanic acid gas into the isophorone mixture, adding a catalyst, and then stirring and mixing to carry out a cyanation reaction to obtain an isophorone nitrile composition containing 4-cyano-3,5,5-trimethylcyclohexanone; Preferably, the molar ratio of the total molar amount of the mixture of α-isophorone and β-isophorone to hydrocyanic acid is 0.8-1.0:1, preferably 0.9-1.0:1; Preferably, the reaction temperature of the cyanidation process is above 100°C, preferably above 110°C; Preferably, the reaction temperature of the cyanidation process is below 200°C, preferably below 190°C; Preferably, the cyanidation process is carried out under normal pressure or pressurized conditions; Preferably, the reaction force of the cyanidation process is greater than 0.01 MPaG and less than 0.5 MPaG; Preferably, the reaction time of the cyanidation step is 0.5 h or more, preferably 1 h or more; Preferably, the reaction time of the cyanidation process is less than 20 hours, preferably less than 18 hours; Preferably, the catalyst used in the cyanidation step is a basic compound, preferably an alkali metal compound, more preferably lithium hydroxide or sodium hydroxide.

6. The preparation method according to any one of claims 3 to 5, characterized in that: Isophorone nitrile and ammonia undergo an imidization reaction under the action of an imidization catalyst, and then enter a hydrogenation reactor to undergo a further hydrogenation reaction in the presence of a hydrogenation catalyst to prepare isophorone diamine; Preferably, the imidization catalyst is an acidic or amphoteric metal oxide, preferably activated alumina and / or titanium oxide; Preferably, the imidization reaction process can be carried out in a solvent or without a solvent, and the preferred solvent is an alcohol, more preferably methanol; Preferably, the hydrogenation reaction catalyst is a supported catalyst, the active component is preferably nickel-based and / or cobalt-based, and the carrier is preferably aluminum oxide or silicon dioxide.

7. The preparation method according to any one of claims 3 to 6, characterized in that: The obtained isophorone diamine reaction liquid needs to be separated and purified by distillation. Usually, low-boiling methanol, water and other low-boiling substances are separated in a light-removal tower, and then the decyanated material enters another distillation tower to separate the isophorone diamine composition. The content of 4-aminomethyl-3,5,5-trimethylcyclohexylamine can also be adjusted by distillation separation, so as to obtain an isophorone diamine composition that meets the use requirements; Preferably, the distillation is carried out in a distillation tower; Preferably, the distillation tower is a packed distillation tower; Preferably, the number of theoretical plates of the distillation tower is 10 or more, preferably 15 or more; Preferably, the number of theoretical plates of the distillation tower is 50 or less, preferably 45 or less; Preferably, the top pressure of the light-removal tower when separating the light components is 10 kPaA or more, preferably 15 kPaA or more; Preferably, the top pressure of the light component removal tower when separating the light components is 30 kPaA or less, preferably 25 kPaA or less; Preferably, the top pressure of the distillation tower is above 0.1 kPaA, preferably above 0.3 kPaA; Preferably, the top pressure of the distillation tower is 5.0 kPaA or less, preferably 3.0 kPaA or less.

8. An epoxy resin composition, characterized in that The epoxy resin composition comprises the following components in parts by weight: Epoxy resin 50-120 parts, preferably 70-90 parts; 5-50 parts of the isophorone diamine composition, preferably 25-40 parts; 20-50 parts of diluent, preferably 30-40 parts; Reaction aid 0.1-5 parts, preferably 0.5-2 parts; The isophorone diamine composition is the isophorone diamine composition according to claim 1 or 2 or the isophorone diamine composition prepared by the preparation method according to any one of claims 3 to 7; Preferably, the epoxy resin is selected from one or more of bisphenol A epoxy resin, bisphenol F epoxy resin, and bisphenol S epoxy resin; Preferably, the epoxy resin is selected from bisphenol A epoxy resin, more preferably one or more of E51 resin, E54 resin, and F170 resin; Preferably, the diluent includes one or more of allyl glycidyl ether, butyl glycidyl ether, and methacrylate glycidyl ether; Preferably, the reaction aid comprises a free radical initiator and a free radical accelerator, and the mass ratio of the two is 1:0.1-1, preferably 1:0.2-0.8; Preferably, the free radical initiator is selected from organic peroxides, azo initiators, preferably one or more of tert-butyl peroxy-2-ethylhexanoate, tert-butyl perbenzoate, dibenzoyl peroxide, and methyl ethyl ketone peroxide; Preferably, the free radical accelerator is selected from organic metal salts and tertiary amines, preferably one or more of cobalt isooctanoate, potassium isooctanoate, copper isooctanoate, pentamethyldiethylenetriamine, N,N-dimethylaniline and N,N-dimethylcyclohexylamine.

9. The method for preparing the epoxy resin composition according to claim 8, characterized in that: The epoxy resin, isophorone diamine composition, diluent and reaction aid are mixed, stirred, vacuum degassed and cured; Preferably, the vacuum degassing conditions are: vacuum degree of 0.05-0.1Mpa, preferably 0.08-0.1Mpa, temperature of 5-45°C, preferably 25-35°C; Preferably, the curing conditions are: pre-curing temperature 30-55°C, time 30-240 min, preferably temperature 35-45°C, time 60-120 min; post-curing temperature 60-100°C, time 30-240 min, preferably temperature 70-85°C, time 60-120 min.

10. Use of the epoxy resin composition according to claim 8 or the epoxy resin composition prepared by the preparation method according to claim 9, which can be applied to wind turbine blades and automobile parts.

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