Benzylamine derivatives, process for their preparation, their use and polyurethane foams

Abstract

The present application relates to the technical field of polyurethane foam preparation, in particular to a benzylamine derivative, a preparation method and application thereof, and a polyurethane foam. The benzylamine derivative is selected from the compounds shown in the following structural formula: wherein R1, R2, R3, R4 and R5 are independently selected from hydrogen or C1-C6 alkyl; m, n, p and q are independently integers from 0 to 6. The benzylamine derivative has the ability to catalyze the reaction of isocyanate and water or polyol, can be used in combination with existing conventional catalysts to match the production process of related polyurethane foam, reduce the odor in the process of material configuration and use, reduce the odor and VOC emission of the final foam product, and meet the performance requirements of downstream market customers in the aspect of environmental protection.

Description

Technical Field

[0001] This invention relates to the field of polyurethane foam preparation technology, and more specifically, to benzylamine derivatives, their preparation methods and applications, and polyurethane foam. Background Technology

[0002] Polyurethane foam is a porous polymer material formed by the stepwise addition polymerization of isocyanate and polyol, with the cell structure controlled by foaming agents, silicone surfactants, catalysts and other additives. According to its hardness, it can be divided into flexible polyurethane foam, rigid polyurethane foam and semi-rigid polyurethane foam. Due to its excellent properties such as lightweight, heat insulation, cushioning and sound absorption, polyurethane foam is widely used in many fields such as construction, furniture, automobiles and home appliances.

[0003] In the preparation of polyurethane foam, tertiary amine catalysts are core additives that regulate the reaction process and ensure successful foam formation. Their key role is to accelerate various reactions involving isocyanates (-NCO), while balancing the rates of gelation and foaming reactions, ultimately determining the foam's pore structure, density, hardness, and mechanical properties. However, many commonly used tertiary amine catalysts are volatile and have irritating odors, making them a major source of odor and VOC (volatile organic compound) contamination in foam products. Therefore, they are a key area for optimization in upgrading the formulation of low-odor, low-VOC polyurethane foam products.

[0004] In view of this, the present invention is proposed. Summary of the Invention

[0005] The purpose of this invention is to provide benzylamine derivatives, their preparation methods, their applications, and polyurethane foams. Embodiments of this invention provide a benzylamine derivative that catalyzes the reaction of isocyanates with water or polyols. This derivative can be used in conjunction with existing conventional catalysts to match relevant polyurethane foam production processes, reducing odor during the preparation and use of the compound, lowering the odor and VOC emissions of the final foam product, and meeting the environmental performance requirements of downstream market customers.

[0006] This invention is implemented as follows: In a first aspect, the present invention provides a benzylamine derivative selected from compounds shown in the following structural formulas: In this context, R1, R2, R3, R4 and R5 are each independently selected from hydrogen or C1-C6 alkyl groups; m, n, p and q are integers from 0 to 6.

[0007] In an optional embodiment, R1, R2, R3, R4 and R5 are each independently selected from hydrogen or C1-C3 alkyl groups, preferably methyl, ethyl or isopropyl.

[0008] In an optional embodiment, it is selected from any of the compounds shown in the following structural formulas: and .

[0009] In a second aspect, the present invention provides a method for preparing the benzylamine derivative described in the foregoing embodiments, comprising: mixing a raw material containing an N-alkylbenzylamine structure with an epoxide to carry out a ring-opening reaction; Alternatively, a nucleophilic substitution reaction can be carried out by mixing a raw material containing a halogenated benzyl structure with a raw material containing an alcohol amine structure to form an intermediate containing a benzylamine alkyl alcohol structure, which is then mixed with a compound containing an aldehyde or ketone structure and formic acid to carry out an alkylation reaction.

[0010] Thirdly, the present invention provides an application of the benzylamine derivative described in the foregoing embodiments in the preparation of polyurethane foam.

[0011] In an optional embodiment, the benzylamine derivative is used as a co-catalyst in the preparation of polyurethane foam.

[0012] Fourthly, the present invention provides a polyurethane foam comprising the benzylamine derivative described in the foregoing embodiments.

[0013] In an optional embodiment, it also includes an organosilicon surfactant.

[0014] In an optional embodiment, it also includes a polyisocyanate.

[0015] In an optional embodiment, it also includes a polyether polyol.

[0016] The present invention has the following beneficial effects: The embodiments of the present invention provide a benzylamine derivative with catalytic properties, which can catalyze the reaction between isocyanate and water or polyol, and can replace existing conventional co-catalysts. It can then be combined with existing catalysts for forming polyurethane foam, which can reduce the odor in the preparation and use of polyurethane foam raw materials, reduce the odor and VOC emissions of the final foam product, and meet the environmental performance requirements of downstream market customers. Detailed Implementation

[0017] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Where specific conditions are not specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall apply. Reagents or instruments whose manufacturers are not specified are all conventional products that can be purchased commercially.

[0018] In a first aspect, the present invention provides a benzylamine derivative selected from compounds shown in the following structural formulas: R1, R2, R3, R4, and R5 are each independently selected from hydrogen or C1-C6 alkyl groups; for example, they are unsubstituted C1-C6 straight or branched alkyl groups such as methyl, ethyl, isopropyl, n-propyl, isobutyl, tert-butyl, n-butyl, and n-pentyl, preferably C1-C3 alkyl groups. m, n, p, and q are integers from 0 to 6, for example, any integer between 0 and 6 such as 0, 1, 2, 3, 4, 5, and 6, preferably any integer between 1 and 3.

[0019] Furthermore, it is selected from any one of the compounds shown in the following structural formulas: (N-methyl-N-hydroxyethylbenzylamine) and (N-Methyl-N-hydroxyisopropylbenzylamine).

[0020] In a second aspect, embodiments of the present invention provide a method for preparing a benzylamine derivative, comprising: mixing a raw material containing an N-alkylbenzylamine structure (such as N-methylbenzylamine) with an epoxide (such as ethylene oxide or propylene oxide) to carry out a ring-opening reaction; Alternatively, a raw material containing a halogenated benzyl structure (such as benzyl chloride) can be mixed with a raw material containing an alcohol amine structure (such as ethanolamine) to carry out a nucleophilic substitution reaction to form an intermediate containing a benzylaminoalkyl alcohol structure (such as benzylaminoethanol), which can then be mixed with a compound containing an aldehyde or ketone structure (such as formaldehyde) and formic acid to carry out an alkylation reaction.

[0021] This invention uses the synthesis of N-methyl-N-hydroxyethylbenzylamine as an example. The specific process is as follows: Under the protection of an inert gas (e.g., nitrogen), N-methylbenzylamine is added to a high-pressure reactor. After multiple purgings with an inert gas (e.g., nitrogen), stirring is started, and the temperature is raised to 60-80°C and stabilized. Ethylene oxide is slowly introduced through a metering device, strictly controlling the reaction temperature not to exceed 80°C and the pressure inside the reactor not to exceed 0.30 MPa. The introduction process continues for 2-4 hours, and then the reaction is maintained at 70-90°C for 2-4 hours until the reactor pressure remains essentially constant, which is considered the reaction endpoint. Subsequently, the temperature is cooled to below 20-40°C, the pressure is slowly released, and residual ethylene oxide is removed by purging with nitrogen to obtain crude N-methyl-N-hydroxyethylbenzylamine, which can be further purified by vacuum distillation.

[0022] Thirdly, the embodiments of the present invention provide the application of the above-mentioned benzylamine derivative in the preparation of polyurethane foam. Specifically, the benzylamine derivative can be used as a co-catalyst or catalyst, specifically as a co-catalyst to partially replace existing conventional catalysts, and is widely used in various polyurethane foam application fields such as rigid polyurethane foam, flexible polyurethane foam, molded high-resilience polyurethane foam, and sprayed polyurethane foam, effectively reducing odor during the preparation and use of the compound and reducing VOC emissions from the foam plastic.

[0023] Fourthly, embodiments of the present invention provide a polyurethane foam, wherein the raw materials for forming the polyurethane foam include benzylamine derivatives.

[0024] Furthermore, the raw materials for forming polyurethane foam also include polyisocyanates used in polyurethane foam. For example, polyisocyanates can be polymeric MDI (also known as PAPI, which is a mixture of 4,4'-diphenylmethane diisocyanate (MDI) and polyphenyl ring polyisocyanates with a functionality greater than 2), toluene diisocyanate (TDI, which is often a mixture of 2,4-isomers and 2,6-isomers in a certain proportion), isophorone diisocyanate (IPDI), hexamethylene diisocyanate (HDI), diphenylmethane diisocyanate (MDI), lysine diisocyanate (LDI), and other conventional polyisocyanates, used alone or in a certain proportion.

[0025] Furthermore, the amount of polyisocyanate used is the existing amount, for example, the mass ratio of polyisocyanate to the benzylamine derivative is 148:(1-4). For example, it is any value between 148:(1-4), such as 148:1, 148:1.5, 148:2, 148:2.5, 148:3, etc.

[0026] Furthermore, the raw materials for forming polyurethane foam also include polyether polyols. For example, these can be polyether polyols prepared by reacting sucrose, glycerol, polyether glycol, sorbitol, etc., as initiators with ethylene oxide or propylene oxide. Alternatively, they can be polyester polyols prepared by polycondensation reactions of dicarboxylic acids (such as adipic acid or sebacic acid) or polyacid anhydrides (such as phthalic anhydride or maleic anhydride) with diols (such as ethylene glycol or 1,4-butanediol) or triols (such as glycerol, with functionality adjusted). By selecting and combining polyol compounds with different properties, polyurethane foams can achieve superior overall performance.

[0027] In rigid polyurethane foam applications, components such as polyols, silicone surfactants, water, catalysts, flame retardants, and physical foaming agents can be pre-mixed to form a composite material, which facilitates subsequent processing.

[0028] Furthermore, the amount of polyether polyol used is the existing amount, for example, the mass ratio of polyether polyol to the benzylamine derivative is 100:(1-4). For example, it is any value between 100:(1-4), such as 100:1, 100:1.5, 100:2, 100:2.5, 100:3, etc.

[0029] Furthermore, the raw materials used to form polyurethane foam also include silicone surfactants. Different commercially available products can be selected based on the specific polyurethane foam application, such as MAYSTA® M88310 (for rigid foam home appliance systems), MAYSTA® M88313 (for rigid foam continuous sheet systems), MAYSTA® M88207 (for rigid foam spraying systems), MAYSTA® M6688LVN (for flexible foam systems), and MAYSTA® M7735LF2 (for molding high-resilience systems), etc.

[0030] Furthermore, the amount of silicone surfactant used is the existing amount, for example, the mass ratio of silicone surfactant to the benzylamine derivative is 5:(1-4). For example, it is any value between 5:(1-4), such as 5:1, 5:1.5, 5:2, 5:2.5, 5:3, etc.

[0031] Furthermore, the raw materials for forming polyurethane foam may also include flame retardants, such as organophosphorus compounds like tri(1-chloro-2-propyl) phosphate (TCPP) or triethyl phosphate (TEP), which can be added alone or in combination.

[0032] Furthermore, the raw materials for forming polyurethane foam may also include chemical foaming agents, such as water.

[0033] Furthermore, in the physical foaming part of this invention, the physical foaming agent can also be hydrocarbon compounds such as n-pentane, cyclopentane and isopentane, dichloromethane, hydrofluoroalkane (HFC), hydrofluoroolefin (HFO), etc.

[0034] The features and performance of the present invention will be further described in detail below with reference to embodiments.

[0035] Example 1 and Comparative Examples 1-2 Examples 1 and 1-2 of this invention provide a polyurethane foam, the composition of which is shown in Table 1 below. Performance tests were conducted on the polyurethane foam. Specifically, free foaming was performed at room temperature (22±2℃), and free foam data such as milky white time and gel time were observed. The catalytic activity of different organic amine catalysts was evaluated by comparing the foaming and gel times of different catalysts at the same addition amount, or by comparing the addition amounts of different organic amine catalysts when gel times were similar. The catalytic tendency of different organic amine catalysts was evaluated by determining the foaming time based on the gel time. The results are shown in Table 1 below.

[0036] Table 1. Composition and performance testing of polyurethane foam

[0037] As shown in Table 1, N-methyl-N-hydroxyethylbenzylamine exhibits certain catalytic activity in rigid foam appliance formulations, leaning towards gelation, and can be used as a co-catalyst in rigid polyurethane foam systems. Compared to conventional MAYCAT® 808 and MAYCAT® BDMA organic amine catalysts, N-methyl-N-hydroxyethylbenzylamine itself has a significantly lower odor.

[0038] The synthesis process of N-methyl-N-hydroxyethylbenzylamine is as follows: Under nitrogen protection, 135.2 g of N-methylbenzylamine was added to a high-pressure reactor. After purging with nitrogen three times, stirring was started, and the temperature was raised to 70°C and stabilized. 46.3 g of ethylene oxide was slowly introduced through a metering device, strictly controlling the reaction temperature to not exceed 80°C and the reactor pressure to not exceed 0.30 MPa. The introduction process continued for 3 hours, followed by holding the reaction at 80°C for 3 hours until the reactor pressure remained essentially constant, which was considered the reaction endpoint. The mixture was then cooled to below 40°C, slowly depressurized, and purged with nitrogen to remove residual ethylene oxide, yielding crude N-methyl-N-hydroxyethylbenzylamine, which can be further purified by vacuum distillation.

[0039] Example 2-3 Examples 2-3 of this invention provide a polyurethane foam, the composition of which is shown in Table 2 below. Performance tests were conducted on the polyurethane foam. Specifically, free foaming was performed at room temperature (22±2℃), and free foam data such as milky white time and gel time were observed. The catalytic activity of different organic amine catalysts was evaluated by comparing the foaming and gel times of different catalysts at the same addition amount, or by comparing the addition amounts of different organic amine catalysts when gel times were similar. The catalytic tendency of different organic amine catalysts was evaluated by comparing the foaming time when the gel time was determined. The odor intensity of different organic amine catalysts was compared by smelling them at a distance of 5–10 cm from the liquid surface for 1–2 seconds. The results are shown in Table 2 below.

[0040] Table 2. Composition and performance tests of polyurethane foam.

[0041] As shown in Table 2, the catalytic activity of N-methyl-N-hydroxyisopropylbenzylamine is slightly weaker than that of N-methyl-N-hydroxyethylbenzylamine, and its amine odor is also slightly lower.

[0042] Example 4 and Comparative Example 3 Example 4 and Comparative Example 3 of this invention provide a polyurethane foam, the composition of which is shown in Table 3 below. Performance tests were also conducted on the above polyurethane foam. Specifically, free foaming was performed at room temperature (22±2℃), and the results of free foam data such as milky white time and gel time are shown in Table 3 below.

[0043] Table 3. Composition and performance tests of polyurethane foam.

[0044] As shown in Table 3, the free foam data after N-methyl-N-hydroxyisopropylbenzylamine partially replaced MAYCAT® MK15 remained basically unchanged, but the odor of the compound itself and during foaming was significantly reduced, which can effectively improve the on-site environment during the processing and production of polyurethane rigid foam continuous boards.

[0045] Example 5 and Comparative Example 4 Example 5 and Comparative Example 4 of this invention provide a polyurethane foam, the composition of which is shown in Table 4 below. The foam was then tested, with the test items as described in Example 1, and the results are shown in Table 4.

[0046] Table 4. Composition and performance tests of polyurethane foam

[0047] As shown in Table 4, the free bubble data after N-methyl-N-hydroxyisopropylbenzylamine partially replaced MAYCAT® 806 remained basically unchanged, but the odor of the compound itself and during foaming was significantly reduced, which can greatly improve the on-site environment during polyurethane foam spraying.

[0048] Example 6 and Comparative Example 5 Example 6 and Comparative Example 5 of this invention provide a polyurethane foam, the composition of which is shown in Table 5 below. The foam was tested by box-type free foaming at room temperature (22±2℃), and the foaming process, including foaming time, final rising height, and falling height, was observed. After the foam matured, the physical properties of the foam product were tested. The results are shown in Table 5.

[0049] Table 5. Composition and performance testing of polyurethane foam

[0050] As shown in Table 5, N-methyl-N-hydroxyethylbenzylamine exhibits certain catalytic activity in flexible foam formulations, resulting in normal foam expansion. Therefore, it can be used as a catalyst in polyurethane flexible foam systems. Flexible foam samples prepared with N-methyl-N-hydroxyethylbenzylamine show normal foam properties and exhibit low odor and low VOC emissions.

[0051] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A benzylamine derivative, characterized in that, It is selected from compounds with the following structural formulas: In this context, R1, R2, R3, R4 and R5 are each independently selected from hydrogen or C1-C6 alkyl groups; m, n, p and q are integers from 0 to 6.

2. The benzylamine derivative according to claim 1, characterized in that, R1, R2, R3, R4 and R5 are each independently selected from hydrogen or C1-C3 alkyl groups, preferably methyl, ethyl or isopropyl.

3. The benzylamine derivative according to claim 1, characterized in that, It is selected from any one of the compounds shown in the following structural formulas: and .

4. A method for preparing the benzylamine derivative according to claim 1, characterized in that, include: A ring-opening reaction was carried out by mixing a raw material containing an N-alkylbenzylamine structure with an epoxide; Alternatively, a nucleophilic substitution reaction can be carried out by mixing a raw material containing a halogenated benzyl structure with a raw material containing an alcohol amine structure to form an intermediate containing a benzylamine alkyl alcohol structure, which is then mixed with a compound containing an aldehyde or ketone structure and formic acid to carry out an alkylation reaction.

5. The use of the benzylamine derivative of claim 1 in the preparation of polyurethane foam.

6. The application according to claim 5, characterized in that, The application of the benzylamine derivative as a cocatalyst in the preparation of polyurethane foam.

7. A polyurethane foam, characterized in that, It includes the benzylamine derivative as described in claim 1.

8. The polyurethane foam according to claim 7, characterized in that, It also includes organosilicon surfactants.

9. The polyurethane foam according to claim 7, characterized in that, It also includes polyisocyanates.

10. The polyurethane foam according to claim 7, characterized in that, It also includes polyether polyols.

Images