An organic amine catalyst, its preparation and use

Abstract

The present application relates to an organic amine catalyst and its preparation and application, the organic amine catalyst of the present application gives consideration to chemical stability and catalytic activity, which is suitable for low GWP environmentally friendly blowing agent, exhibits excellent catalytic activity and system compatibility in polyurethane foam production, can effectively improve the stability and structural uniformity of foam products, and the catalyst preparation process is simple, high in atomic economy, and has important application value.

Description

Technical Field

[0001] This invention belongs to the field of catalysts, and specifically relates to an organic amine catalyst and its preparation and application. Background Technology

[0002] Polyurethane foam is produced by reacting polyols and isocyanates in the presence of catalysts, foaming agents, surfactants, crosslinking agents, and other additives. The main reactions involved are: the gelation reaction of polyols and isocyanates to form urethanes; the foaming reaction of isocyanates and water to form carbon dioxide and urea bonds; and the crosslinking reaction of isocyanates themselves trimerizing to form isocyanurate rings under the action of specific catalysts. Industrially, tertiary amine catalysts that promote foaming are usually used in combination with metal catalysts that promote gelation / trimerization to achieve the optimal balance between foaming and curing.

[0003] Catalysts not only significantly influence the reaction rates but also greatly affect the curing speed, moldability, density reduction, and physical properties of polyurethane foams. Fluorocarbons have long been considered one of the representative physical blowing agents for polyurethane foams. Fluorocarbons, especially when used in rigid polyurethane foams, act not only as blowing agents due to their volatility but also contribute to the low thermal conductivity of rigid polyurethane foams by encapsulating them within their independent bubble structure. Among fluorocarbons, the reduction of ozone-depleting chlorofluorocarbons (such as trichlorofluoromethane and dichlorofluoromethane, the so-called CFCs) and hydrochlorofluorocarbons (such as dichlorofluoroethane, the so-called HCFCs), the improvement of working environments, and the suppression of volatile organic compound (VOC) emissions from products have received considerable attention. Therefore, as foaming agents, those that do not damage the ozone layer (HFO types such as HFO-1233zd and HFO-1336mzz) or those that have low ozone-depleting properties (so-called HFC types such as tetrafluoroethane, 1,1,1,3,3-pentafluoropropane, and 1,1,1,3,3-pentafluorobutane) are now widely used.

[0004] However, in the polyurethane foaming reaction, the carbon-carbon double bonds in fluorocarbon molecules and the active fluorine groups exhibit strong reactivity. In actual foaming operations, they readily undergo addition, defluorination, or cyclization reactions with commonly used tertiary amine catalysts (such as DABCO, BDMA, PMDETA, TEA, etc.), leading to catalyst deactivation, foam collapse, delayed foaming, and disordered microporous structure. Literature reports indicate that the side reactions between the catalyst and HFO not only cause performance problems but may also form fluorine-containing byproducts that corrode equipment, affecting the stable operation of the plant.

[0005] The literature has already attempted to develop catalyst systems with higher stability to HFO, such as:

[0006] CN109347892A (Wanhua Chemical) suppresses side reactions with HFO by adding conventional catalysts along with antioxidants and metal complexes. It does not directly improve the catalyst structure but uses an external stabilizer for slow release to prevent catalyst deactivation. This approach has the risks of system complexity, multiple components, narrow formulation window, and stabilizer migration and catalytic activity inhibition. WO2020032457A1 (Evonik) develops a class of organic amines with strong electron-withdrawing groups (such as amides and fluoroalkyl groups) to enhance the electron affinity of the catalyst center, thereby reducing the nucleophilic addition reaction of HFO. Introducing polar electron-withdrawing groups near the basic core slows down side reactions. However, catalytic activity and foam reaction rate are significantly affected, and mold opening time is difficult to control. WO 2025024345 (Huntsman) uses the same strategy, introducing electron-withdrawing groups after Michael addition reactions of dimethylamine with different acrylates and acrylamides, thereby reducing the nucleophilic addition reaction of HFO; however, the catalytic activity is also significantly reduced.

[0007] Although the aforementioned patents propose various design strategies, they still generally share the following common problems: it is difficult to balance chemical stability and catalytic efficiency; and they have poor adaptability to specific HFO systems (such as 1233zd and 1336mzz). Summary of the Invention

[0008] To address the shortcomings of existing technologies, the technical problem this invention aims to solve is to provide an organic amine catalyst, its preparation, and its application. This invention provides a novel organic amine catalyst suitable for HFO (hydrofluoroolefin) low-GWP blowing agent systems. This catalyst exhibits excellent chemical stability and can effectively avoid problems such as catalytic failure and unstable foaming quality caused by reaction with HFO during the foaming process.

[0009] This invention provides an organic amine catalyst, the organic amine catalyst having the following structural formula:

[0010] Where n≥0; R1 is at least one of cyclic alkyl, aromatic, and heterocyclic groups; R2 is an alkyl group.

[0011] Preferably, the cyclic alkyl group is a C3-C7 cyclic alkane; more preferably, the cyclic alkyl group is a C5-C6 cyclic alkane. , One or more of them;

[0012] Preferably, the aromatic group includes The heterocyclic group includes , , , One or more of them.

[0013] Preferably, R2 is a C1-C4 alkyl group; and n is 0~5.

[0014] More preferably, R2 is one or more of methyl, ethyl, isopropyl, and methylethyl, and more preferably methyl.

[0015] More preferably, n is 0 or 1.

[0016] This invention provides a method for preparing an organic amine catalyst, comprising:

[0017] Step (1) In the presence of a hydrogen atmosphere and a metal catalyst, diethylenetriamine undergoes a reductive amination reaction with a carbonyl compound containing a cyclic structure to obtain an intermediate;

[0018] In step (2), under a hydrogen atmosphere and in the presence of a metal catalyst, the above intermediate and aldehyde compound continue to undergo a reductive alkylation reaction to obtain an organic amine catalyst.

[0019] Preferably, the carbonyl compound containing a cyclic structure in step (1) includes one or more of cyclopentanone, cyclohexanone, acetophenone, and furfural; more preferably, the carbonyl compound containing a cyclic structure is at least one of cyclohexanone and cyclopentanone.

[0020] Preferably, the catalyst in steps (1) and (2) includes one or more of Pd / C, Ru / C, and Pt / C;

[0021] Preferably, the aldehyde compound in step (2) includes one or more of formaldehyde, acetaldehyde, and propionaldehyde; more preferably, it is formaldehyde.

[0022] Preferably, in step (1), the molar ratio of diethylenetriamine to carbonyl compound containing a cyclic structure is 1:1.9~2.2, more preferably 1:2.0-2.1; in step (2), the molar ratio of intermediate to aldehyde compound is 1:3.2~4.5, more preferably 1:3.3~3.6.

[0023] Furthermore, the method for preparing the organic amine catalyst is as follows:

[0024] Step (1) In the presence of a hydrogen atmosphere and a metal catalyst, diethylenetriamine undergoes a reductive amination reaction with a carbonyl compound containing a cyclic structure to obtain an intermediate. Specifically, this includes: adding a catalyst to the reactor, introducing hydrogen at a rate of 150-300 mL / min, controlling the pressure at 80-120 kg, raising the temperature to 150-180 °C, and continuously introducing diethylenetriamine and the carbonyl compound containing a cyclic structure into the reactor to obtain the intermediate.

[0025] The diethylenetriamine and the carbonyl compound containing a cyclic structure were continuously fed into the reactor using an HPLC pump or directly.

[0026] Step (2) In the presence of hydrogen atmosphere and metal catalyst, the above intermediate and aldehyde compound continue to undergo reduction alkylation reaction, specifically as follows: then the catalyst is added to the reactor, hydrogen is introduced at a rate of 300-400 ml / min, the pressure is controlled at 100-150 kg, the temperature is raised to 120-180℃, the intermediate solution and aldehyde compound are continuously introduced into the reactor respectively, and distillation is performed to obtain organic amine catalyst;

[0027] The intermediate solution and aldehyde compound are continuously fed into the reactor using an HPLC pump, or they are fed directly into the reactor.

[0028] This invention provides the application of any of the described organic amine catalysts in the preparation of polyurethane foam materials.

[0029] This invention provides a polyurethane foam material, comprising, by weight, the following components:

[0030] 100 parts of polyol;

[0031] Flame retardant 0-25 parts;

[0032] Surfactant 0.1-2 parts;

[0033] 0-5 parts water

[0034] 5-20 parts of catalyst;

[0035] 5-20 parts of foaming agent;

[0036] 0-6 parts of solubilizer;

[0037] 100-150 parts isocyanate;

[0038] The catalyst is any of the organic amine catalysts described above.

[0039] Preferably, the components, by mass parts, include:

[0040] 100 parts of polyol;

[0041] 5-25 parts flame retardant;

[0042] Surfactant 0.5-2 parts;

[0043] 0.1-3 parts water

[0044] 5-15 parts of catalyst;

[0045] 10-20 parts of foaming agent;

[0046] 1-5 parts of solubilizer;

[0047] Isocyanate 110-135;

[0048] Preferably, the polyol is one or more of polyester polyols and polyether polyols.

[0049] Further, the polyester polyol is one or more of aromatic polyester polyols and aliphatic polyester polyols, with a functionality of 1.8 to 3.0 and a hydroxyl value of 250 to 450 mgKOH / g; preferably, the polyester polyol is one or more of Stepanpol PS-3152, PS-2352, PS-2412, DSM Rynel series, and BASF Lupraphen series.

[0050] Furthermore, the polyether polyol is a polyether polyol containing one or more of sucrose, sorbitol, glycerol, and amines as initiators, with a functionality of 3-8 and a hydroxyl value of 300-600 mgKOH / g. Preferably, the polyether polyol includes, but is not limited to, one or more of NJ-M330, NJ-6209, Suzhou Fengsha S380, Carpenter GR-380, and Voranol 490.

[0051] Preferably, the isocyanate includes diphenylmethane diisocyanate (MDI) type isocyanate, and more preferably, it includes polymeric MDI, a mixture of diphenylmethane diisocyanate and polymeric MDI, with an NCO mass fraction of 30.0-32.0%, an average functionality of 2.6-3.0, and a viscosity of 50-700 mPa·s at 25°C; preferably, the isocyanate includes one or more of Suprasec 5005, Suprasec 5028, Wannate PM-200, PM-2010, M20S, Desmodur 44V20, Lupranate M20S, Pap i 135, and Ongronate 4040.

[0052] Preferably, the flame retardant comprises a reactive or additive phosphate flame retardant, wherein the phosphate flame retardant is selected from one or more of tris(2-chloroisopropyl) phosphate (TCPP), tris(1,3-dichloroisopropyl) phosphate (TDCP), tris(2-chloroethyl) phosphate (TCEP), dimethylpropanephosphonate (DMMP), and triethyl phosphate (TEP), with TCPP being preferred.

[0053] Preferably, the surfactant is an organosilicon surfactant, and more preferably a non-hydrolyzable siloxane-polyether copolymer. More preferably, it is selected from one or more of Evonik Tegostab B8460, B8481, B8491, B8545, Momentive Niax L-618, L-193, L-5340, Shanghai Xinrui New Materials Loca S193, Momentive DC5604, DC2525, and Evonik B8486.

[0054] Preferably, the foaming agent includes HFO foaming agent; further, the HFO foaming agent is at least one of HFO-1233zd(E) and HFO-1336mzz(Z).

[0055] Preferably, the solubilizer is an HFO solubilizer.

[0056] This invention provides a method for preparing the polyurethane foam material, comprising:

[0057] Weigh each component according to the mass fraction, mix the polyol, flame retardant, surfactant, water, catalyst, foaming agent, solubilizer, and isocyanate, and react to obtain polyurethane foam material.

[0058] This invention provides an application of the polyurethane foam material in building spray insulation, cold storage panels, pipeline insulation, or cold chain transportation equipment.

[0059] Beneficial effects

[0060] This invention provides a novel organic amine catalyst that balances chemical stability and catalytic activity, which is of great significance for improving the stability and structural uniformity of polyurethane foam products.

[0061] This invention relates to an organic amine catalyst mixture with excellent stability for polyurethane foam systems. This type of catalyst mixture exhibits excellent catalytic activity and system compatibility in the production of polyurethane foam, especially when using low-GWP (Global Warming Potential) environmentally friendly blowing agents such as HFO-1233zd(E) and HFO-1336mzz(Z).

[0062] The preparation method of this invention is simple and highly atom-economical. Detailed Implementation

[0063] The present invention will be further illustrated below with reference to specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Furthermore, it should be understood that after reading the teachings of this invention, those skilled in the art can make various alterations or modifications to the invention, and these equivalent forms also fall within the scope defined by the appended claims.

[0064] Example 1

[0065] A 250 mL fixed-bed reactor was loaded with 200 g of 3*3 mm metal catalyst (1% Pd-C). Hydrogen was introduced into the reactor at a rate of 180 mL / min using a mass flow meter, and the pressure was controlled at 80 kg. The temperature was raised to 160 °C, and diethylenetriamine (50 g / h) and cyclohexanone (95 g / h) were continuously introduced into the reactor (molar ratio 1:2) using an HPLC pump. After solvent removal, the content of the target product was measured to be 89.6% by GC.

[0066]

[0067] Example 2

[0068] A 250 mL fixed-bed reactor was loaded with 200 g of 3*3 mm metal catalyst (1% Pd-C). Hydrogen was introduced into the reactor at a rate of 300 mL / min using a mass flow meter, and the pressure was controlled at 100 kg. The temperature was raised to 130 °C. A methanol solution (100 g / h, 50% solution) and 37% formaldehyde (55 g / h) of compound I were continuously introduced into the reactor using an HPLC pump (molar ratio of 1:3.6). After distillation of the crude product, compound II was obtained, with a purity of 98.2% based on GC analysis.

[0069]

[0070] Example 3

[0071] A 250 mL fixed-bed reactor was loaded with 200 g of 3*3 mm metal catalyst (1% Pd-C). Hydrogen was introduced into the reactor at a rate of 200 mL / min using a mass flow meter. The pressure was controlled at 80 kg. The temperature was raised to 150 °C. Diethylenetriamine (50 g / h) and cyclopentanone (80 g / h) were continuously introduced into the reactor (molar ratio 1:2) using an HPLC pump. The target product content was measured to be 90.2% by GC.

[0072]

[0073] Example 4

[0074] A 200 g 3*3 mm metal catalyst (1% Pd-C) was loaded into a 250 mL fixed-bed reactor. Hydrogen was introduced into the reactor at a rate of 360 mL / min using a mass flow meter, and the pressure was controlled at 100 kg. The temperature was raised to 120 °C. A methanol solution (100 g / h, 60% solution) and 37% formaldehyde (73 g / h) of compound III were continuously introduced into the reactor using an HPLC pump (molar ratio of 1:3.6). After distillation of the crude product, compound IV was obtained, with a purity of 99.1% based on GC analysis.

[0075]

[0076] Example 5

[0077] A 250 mL fixed-bed reactor was loaded with 200 g of 3*3 mm metal catalyst (1% Pd-C). Hydrogen was introduced into the reactor at a rate of 180 mL / min using a mass flow meter, and the pressure was controlled at 80 kg. The temperature was raised to 150 °C, and diethylenetriamine (50 g / h) and cyclohexylformaldehyde (106 g / h) were continuously introduced into the reactor (molar ratio 1:2) using an HPLC pump. The target product content was measured to be 86.2% by GC.

[0078]

[0079] Example 6

[0080] A 200 g 3*3 mm metal catalyst (1% Pd-C) was loaded into a 250 mL fixed-bed reactor. Hydrogen was introduced into the reactor at a rate of 320 mL / min using a mass flow meter, and the pressure was controlled at 100 kg. The temperature was raised to 130 °C. A methanol solution (100 g / h, 50% solution) and 37% formaldehyde (7348 g / h) of V were continuously introduced into the reactor using an HPLC pump (molar ratio of 1:3.45). After distillation of the crude product, compound VI was obtained, with a purity of 97.8% based on GC analysis.

[0081]

[0082] Example 7

[0083] A 250 mL fixed-bed reactor was loaded with 200 g of 3*3 mm metal catalyst (1% Pd-C). Hydrogen was introduced into the reactor at a rate of 300 mL / min using a mass flow meter, and the pressure was controlled at 120 kg. The temperature was raised to 180 °C. Diethylenetriamine (40 g / h) and furfural (72 g / h) were continuously introduced into the reactor (molar ratio 1:2) using an HPLC pump. The resulting mixture was introduced into the same reactor at a rate of 30 g / h. At the same time, 37% formaldehyde was introduced into the reactor at a rate of 32 g / h, and the pressure was maintained at 150 kg. After distillation of the crude product, compound VII was obtained, with a purity of 95.8% based on GC analysis.

[0084]

[0085] Example 8

[0086] This example investigated the catalytic performance and storage stability of compound II (1,1,4,7,7-pentamethyl-4,7-dicyclohexyldiethylenetriamine) prepared in Example 2 in a rigid spray polyurethane foam system containing HFO blowing agent.

[0087] The foam formulation was prepared according to the mass parts shown in Table 1. Foaming was performed using a manual free-rising cup, and the foam rise height-time curve and rise rate-time curve were recorded using the FOAMAT sonar testing system to characterize the initial reactivity of the catalyst by measuring the time required to reach 80% of the maximum foam height.

[0088] To evaluate storage stability, the A-material (polyol + flame retardant + surfactant + water + catalyst + foaming agent + solubilizer) prepared according to Table 1 was dispensed into sealed aluminum bottles and aged in a 50°C constant temperature oven for 4 weeks. Samples were taken at weeks 0, 1, 2, and 4, and mixed with fresh isocyanate (130 parts) under the same conditions for manual cup foaming tests. The time required to reach 80% of the maximum foam height was recorded, and the percentage change relative to the initial value was calculated.

[0089] The polyurethane formulation, in parts by weight, is as follows:

[0090] Table 1: Formulations used in this embodiment

[0091]

[0092] Polyol: A mixture of Stepan Polyester (Stepanpol PS3152) and Jurong Ningwu New Materials Co., Ltd. polyether polyol (NJ-M330);

[0093] Flame retardant: WSFR-TCPP phosphate flame retardant from Wansheng Group;

[0094] Surfactant: Shanghai Xinrui New Materials' Loca S193 surfactant;

[0095] Catalysts: Novel amine catalysts

[0096] HFO: Obtained from Honeywell LBA (i.e., HFO-1233zd(E))

[0097] HFO solubilizer: The HFO solubilizer is from Shanghai Xinrui New Materials XR PM301.

[0098] Polyol, flame retardant, surfactant, water, catalyst, HFO solubilizer, and HFO were mixed and placed in a 500ml plastic beaker. Huntsman Suprasec-5005 MDI (130 parts) was added and mixed for 3 seconds at 4000 RPM using a laboratory dispenser manufactured in China. Immediately after mixing, the beaker was placed under sonar on a Foamat machine (FOAMATMesstechnik GmbH), and the foam rise curve was obtained using software equipment. The ROR curve was measured for 120 seconds. Three samples of the same formulation were stored in three sealed aluminum bottles and heated at 50°C for four weeks. The ROR curves were monitored at weeks 0, 1, 2, and 4. The observations are summarized in Table 2.

[0099] Table 2

[0100]

[0101] As can be clearly seen from Table 2, the catalyst loses its reactivity after 4 weeks at 50°C. However, the catalyst was found to have excellent stability within 2 weeks at 50°C. After 2 weeks at 50°C, it begins to lose its reactivity. By the fourth week, at 50°C, it had lost 25.4% of its original reactivity.

[0102] Example 9

[0103] The pot life study was conducted using catalyst IV in the same manner as in Example 8.

[0104] Table 3: Formulations used in this embodiment

[0105]

[0106] Table 4

[0107]

[0108] As shown in Table 4, the catalyst loses its reactivity after 4 weeks at 50°C. However, the catalyst was found to have excellent stability within 2 weeks at 50°C. After 2 weeks at 50°C, it begins to lose its reactivity. By the fourth week, at 50°C, it had lost 23% of its original reactivity.

[0109] Example 10

[0110] The pot life study was conducted using catalyst VI in the same manner as in Example 8.

[0111] Table 5: Formulations used in this embodiment

[0112]

[0113] Table 6

[0114]

[0115] As shown in Table 6, after aging at 50°C for four weeks, the rise time of the catalyst increased by 65.3% compared to its original value, indicating poor stability.

[0116] Example 11

[0117] The pot life study was conducted using catalyst VII in the same manner as in Example 8.

[0118] Table 7: Formulations used in this embodiment

[0119]

[0120] Table 8

[0121]

[0122] As shown in Table 8, the catalyst lost significant reactivity after four weeks at 50°C. After four weeks of aging, the rise time increased by 72.7% compared to its original value.

[0123] Comparative Example 1

[0124] The standard catalyst N,N,N',N'',N''-pentamethyldiethylenetriamine (PMDETA) used in the rigid sprayed foam polyurethane system was subjected to a pot life study in the same manner as in Example 8.

[0125] Table 9. Formulations used in this embodiment.

[0126]

[0127] Table 10

[0128]

[0129] As can be clearly seen from Table 10, the formulation lost its activity, as indicated by the 232% increase in rise time over 4 weeks of thermal aging. This commercially available catalyst is too unstable to be used with HFO blowing agents.

[0130] Compound II and HFO in this invention exhibit excellent stability and are valuable for industrial applications.

Claims

1. An organic amine catalyst, characterized in that, The organic amine catalyst has the following structural formula: (I), where n≥0; R1 is at least one of cyclic alkyl, aromatic, and heterocyclic groups; R2 is an alkyl group.

2. The organic amine catalyst according to claim 1, characterized in that, The cyclic alkyl group is a C3-C7 cyclic alkane; the aromatic group includes... The heterocyclic group includes , , , One or more of them; R2 is a C1-C4 alkyl group; n is 0~5.

3. The organic amine catalyst according to claim 2, characterized in that, The cyclic alkyl group is a C5-C6 cycloalkane. , One or more of the following; R2 is one or more of methyl, ethyl, isopropyl, and methylethyl; n is 0 or 1.

4. A method for preparing an organic amine catalyst, comprising: Step (1) In the presence of a hydrogen atmosphere and a metal catalyst, diethylenetriamine reacts with a carbonyl compound containing a cyclic structure to obtain an intermediate; In step (2), the above intermediate reacts with aldehydes in the presence of hydrogen atmosphere and metal catalyst to obtain organic amine catalyst.

5. The preparation method according to claim 4, characterized in that, The carbonyl compounds containing cyclic structures in step (1) include one or more of cyclopentanone, cyclohexanone, acetophenone, and furfural; The catalysts in steps (1) and (2) include one or more of Pd / C, Ru / C, and Pt / C; The aldehyde compounds in step (2) include one or more of formaldehyde, acetaldehyde, and propionaldehyde; In step (1), the molar ratio of diethylenetriamine to the carbonyl compound containing a cyclic structure is 1:1.9~2.2; In step (2), the molar ratio of the intermediate to the aldehyde compound is 1:3.2~4.

5.

6. The use of the organic amine catalyst according to any one of claims 1-3 in the preparation of polyurethane foam materials.

7. A polyurethane foam material, characterized in that, By mass parts, the components include: 100 parts of polyol; Flame retardant 0-25 parts; Surfactant 0.1-2 parts; 0-5 parts water 5-20 parts of catalyst; 5-20 parts of foaming agent; 0-6 parts of solubilizer; 100-150 parts isocyanate; The catalyst is any one of the organic amine catalysts described in claims 1-3.

8. The polyurethane foam material according to claim 7, characterized in that, The polyol is one or more of polyester polyols and polyether polyols; The isocyanate includes diphenylmethane diisocyanate (MDI) type isocyanate; The flame retardant includes reactive or additive phosphate flame retardants, wherein the phosphate flame retardant is selected from one or more of tris(2-chloroisopropyl) phosphate TCPP, tris(1,3-dichloroisopropyl) phosphate TDCP, tris(2-chloroethyl) phosphate TCEP, dimethylpropanephosphonate DMMP, and triethyl phosphate TEP. The surfactant is an organosilicon surfactant, wherein the organosilicon surfactant includes one or more of Evonik Tegostab B8460, B8481, B8491, B8545, Momentive Niax L-618, L-193, L-5340, Loca S193, DC5604, DC2525, and B8486. The foaming agent includes HFO foaming agent; the solubilizer is HFO solubilizer.

9. A method for preparing the polyurethane foam material according to claim 7, comprising: Weigh each component according to the mass fraction, mix the polyol, flame retardant, surfactant, water, catalyst, foaming agent, solubilizer, and isocyanate, and react to obtain polyurethane foam material.

10. The application of the polyurethane foam material of claim 7 in building spray insulation, cold storage panels, pipeline insulation or cold chain transportation equipment.

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