Guaiacol-based organic amine cross-linking agent, preparation method thereof and polyurethane foam

Abstract

The invention relates to the technical field of polyurethane foam, in particular to a guaiacol-based organic amine cross-linking agent, a preparation method of the guaiacol-based organic amine cross-linking agent and polyurethane foam. The guaiacol-based organic amine cross-linking agent is selected from compounds shown in the following structural formula: # imgabs0 #, R1 is selected from # imgabs1 #, R2 and R3 are respectively and independently selected from hydrogen, C1-C5 unsubstituted alkyl and hydroxyl substituted C2-C5 alkyl, and at least one of R2 and R3 is hydroxyl substituted C2-C5 alkyl; # imgabs2 # represents a 5-to 7-membered ring; r4 is N or C, and R5 represents a hydroxyl-substituted C2-C5 alkyl group. The cross-linking agent provided by the embodiment of the invention can improve the flatulence, trepanning and supporting performance of polyurethane foam, and meanwhile, the requirements for the tensile strength, the elongation, the rebound resilience, the comfort factor and the like of the foam are met.

Description

Technical Field

[0001] The invention relates to the technical field of polyurethane foams, in particular to a guaiacol-based organic amine cross-linking agent, a preparation method thereof and polyurethane foam. Background Art

[0002] Polyurethane foam is a widely used polymer material. Its properties can be regulated by adding various additives. Among them, the application of crosslinking agents plays a vital role in improving the performance of polyurethane foam. Crosslinking agents are substances that can form chemical bonds between polymer molecular chains, thereby increasing the crosslinking density of the polymer network. During the synthesis process of polyurethane foam, crosslinking agents can form more crosslinking points between polyurethane molecular chains, thereby significantly improving the mechanical properties, thermal stability and dimensional stability of the foam.

[0003] In terms of mechanical properties, the introduction of cross-linking agents can increase the strength and stiffness of polyurethane foam. Due to the presence of cross-linking points, the slippage between molecular chains is limited when the foam is subjected to external forces, so that it can withstand greater loads. This allows polyurethane foam to exhibit better performance in application scenarios that need to withstand certain pressures and impacts, such as car seats, mattresses, etc. Thermal stability is an important factor that needs to be considered in many applications of polyurethane foam. The use of cross-linking agents can increase the decomposition temperature and heat deformation temperature of polyurethane foam. The cross-linked structure can hinder the thermal motion of molecular chains and reduce heat transfer, thereby effectively improving the heat resistance of the foam, enabling it to maintain structural integrity and performance stability in high temperature environments.

[0004] With the development of technology and social progress, traditional cross-linking agents are gradually unable to meet the requirements of application and the expansion of application scope. In view of this, it is necessary to accelerate the development of new organic amine cross-linking agents to replace existing cross-linking agents; at the same time, by introducing unique structures to improve their application performance and improve the quality of polyurethane foam, such as improving the inflation, opening and supporting performance of high-resilience molded foam, and meeting the foam tensile strength, elongation, resilience and comfort factor, so that polyurethane foam plastics can meet different application requirements.

[0005] In view of this, the present invention is proposed. Summary of the invention

[0006] The object of the present invention is to provide a guaiacol-based organic amine cross-linking agent, a preparation method thereof and a polyurethane foam. The cross-linking agent provided in the embodiment of the present invention can improve the inflation, opening and supporting properties of the polyurethane foam, and at the same time, meet the requirements of the foam tensile strength, elongation, rebound performance and comfort factor.

[0007] The present invention is achieved in that:

[0008] In a first aspect, the present invention provides a guaiacol-based organic amine cross-linking agent selected from the compounds represented by the following structural formula:

[0009] Among them, R 1 Selected from R 2 and R 3 are independently selected from hydrogen, C1-C5 unsubstituted alkyl and hydroxy-substituted C2-C5 alkyl, and R 2 and R 3 At least one of them is a C2-C5 alkyl group substituted with a hydroxyl group;

[0010] Represents a 5-7 membered ring; R 4 N or C, R 5 It represents a C2-C5 alkyl group substituted with a hydroxy group.

[0011] In an alternative embodiment, R 1 Selected from R 2 and R 3 are independently selected from hydrogen, C1-C5 unsubstituted alkyl and hydroxy-substituted C2-C5 alkyl, and R 2 and R 3 At least one of them is a C2-C5 alkyl group substituted with a hydroxyl group; 5 It represents a C2-C5 alkyl group substituted with a hydroxy group.

[0012] In an alternative embodiment, R 1 Any one selected from the groups shown in the following structural formulas:

[0013]

[0014]

[0015] In a second aspect, the present invention provides a method for preparing the guaiacol-based organic amine cross-linking agent described in the aforementioned embodiment, comprising: mixing guaiacol, an amine compound and polyformaldehyde for reaction.

[0016] In an optional embodiment, the method comprises: mixing the guaiacol, the amine compound, the paraformaldehyde and the catalyst at 60-120° C. and reacting for 2-10 hours.

[0017] In an optional embodiment, the molar ratio of the guaiacol, the amine compound and the paraformaldehyde is 1:(1-5):(1-3).

[0018] In an optional embodiment, the amount of the catalyst used is 0.1 to 3 wt%.

[0019] In an optional embodiment, the amine compound is selected from any one of diisopropanolamine, N-hydroxyethylpiperazine, diethanolamine, methylethanolamine, monoisopropanolamine, tris(hydroxymethyl)aminomethane and 2-amino-1,3-propanediol.

[0020] In an optional embodiment, the catalyst is any one of p-toluenesulfonic acid, acetic acid, concentrated sulfuric acid, phosphoric acid, fluoroboric acid, boron trifluoride etherate, boron trifluoride acetic acid, zinc chloride, aluminum chloride, magnesium chloride and ferric chloride.

[0021] In a third aspect, the present invention provides a polyurethane foam prepared by using the guaiacol-based organic amine cross-linking agent described in the aforementioned embodiment.

[0022] The present invention has the following beneficial effects: the cross-linking agent provided by the embodiment of the present invention uses guaiacol as a connecting matrix to synthesize a guaiacol-based cross-linking agent, and the cross-linking agent can improve the opening performance and supporting performance of high-resilience polyurethane foam products. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0024] Figure 1 The infrared spectrum of the guaiacol-based organic amine cross-linking agent provided in Example 1 of the present invention;

[0025] Figure 2 This is the hydrogen spectrum of the guaiacol-based organic amine cross-linking agent provided in Example 1 of the present invention. DETAILED DESCRIPTION

[0026] In order to make the purpose, technical scheme and advantages of the embodiments of the present invention clearer, the technical scheme in the embodiments of the present invention will be described clearly and completely below. If the specific conditions are not specified in the embodiments, they are carried out according to conventional conditions or conditions recommended by the manufacturer. If the manufacturer of the reagents or instruments used is not specified, they are all conventional products that can be purchased commercially.

[0027] The present invention provides a guaiacol-based organic amine cross-linking agent, which is selected from the compounds represented by the following structural formula:

[0028] Among them, R 1 Selected from R 2 and R 3are independently selected from hydrogen, C1-C5 unsubstituted alkyl and hydroxy-substituted C2-C5 alkyl, and R 2 and R 3 At least one of them is a C2-C5 alkyl group substituted with a hydroxy group.

[0029] For example, the C1-C5 unsubstituted alkyl group is selected from branched or straight chain alkyl groups such as methyl, ethyl, isopropyl, n-propyl, n-butyl, isobutyl, tert-butyl, n-pentyl, isopentyl and tert-pentyl.

[0030] The C2-C5 alkyl in the hydroxy-substituted C2-C5 alkyl represents a branched or straight-chain alkyl such as ethyl, isopropyl, n-propyl, n-butyl, isobutyl, tert-butyl, n-pentyl, isopentyl and tert-pentyl. That is, the hydroxy-substituted C2-C5 alkyl refers to an alkyl such as ethyl, isopropyl, n-propyl, n-butyl, isobutyl, tert-butyl, n-pentyl, isopentyl and tert-pentyl, in which one hydrogen on one carbon or multiple hydrogens on multiple carbons are replaced by hydroxyl groups. For example, specifically, Any one of .

[0031] R 1 You can also in, Represents a 5-7 membered ring; R 4 N or C, R 5 represents a C2-C5 alkyl group substituted with a hydroxyl group. More preferably

[0032]

[0033] The crosslinking agent added in the polyurethane foaming in the prior art is usually a small molecule compound such as triethanolamine, trimethylolpropane, glycerol, etc., but the prepared high-resilience polyurethane foam products have poor opening performance and low support performance. The guaiacol-based organic amine crosslinking agent provided in the embodiment of the present invention uses guaiacol as a connecting matrix, and the guaiacol structure has an opening performance, which can improve the opening performance of high-resilience polyurethane foam products. At the same time, it contains a benzene ring structure, which can improve the support performance of high-resilience polyurethane foam products.

[0034] In a second aspect, the present invention provides a method for preparing the guaiacol-based organic amine crosslinking agent described in the aforementioned embodiment, comprising: mixing guaiacol, an amine compound and polyformaldehyde for reaction. Multiple small molecule amine compounds can be grafted through Mannich reaction and epoxy ring-opening reaction, and grafting modification can be performed according to the performance requirements of high-resilience polyurethane foam products. A new route is provided for the synthesis of polyurethane organic amine crosslinking agents. The preparation method of the organic amine crosslinking agent is simple, easy to operate, and suitable for industrial production.

[0035] Specifically, guaiacol, polyformaldehyde and amine compounds are added into a reactor in a molar ratio of 1:(1-3):(1-5), 0.1-3 wt % of a catalyst is added, and the mixture is heated to 60-120° C. at normal pressure for 2-10 hours to obtain a guaiacol-based organic amine cross-linking agent.

[0036] Specifically, the molar ratio of guaiacol to paraformaldehyde is any value between 1:(1-3) such as 1:1, 1:1.5, 1:2, 1:2.5 and 1:3. The molar ratio of guaiacol to the amine compound is any value between 1:(1-5) such as 1:1, 1:2, 1:3, 1:4 and 1:5.

[0037] The amount of the catalyst used is 0.1wt%, 0.5wt%, 1wt%, 1.5wt%, 2.0wt%, 2.5wt% or 3.0wt%, or any value between 0.1-3.0wt%.

[0038] The reaction temperature is any value between 60-120° C., such as 60° C., 70° C., 80° C., 90° C., 100° C., 110° C., and 120° C. The reaction time is any value between 2-10 hours, such as 2 hours, 3 hours, 4 hours, 5 hours, 6 hours, 7 hours, 8 hours, 9 hours, and 10 hours.

[0039] Amine compounds according to R 1 The group confirmation includes, for example, but is not limited to, any one of diisopropanolamine, N-hydroxyethylpiperazine, diethanolamine, methylethanolamine, monoisopropanolamine, tris(hydroxymethyl)aminomethane and 2-amino-1,3-propanediol.

[0040] The catalyst is any one of p-toluenesulfonic acid, acetic acid, concentrated sulfuric acid, phosphoric acid, fluoroboric acid, boron trifluoride etherate, boron trifluoride acetic acid, zinc chloride, aluminum chloride, magnesium chloride and ferric chloride.

[0041] In a third aspect, the present invention provides a polyurethane foam prepared by using the guaiacol-based organic amine cross-linking agent described in the aforementioned embodiment.

[0042] The features and performance of the present invention are further described in detail below in conjunction with the embodiments.

[0043] Example 1

[0044] The embodiment of the present invention provides a guaiacol-based organic amine cross-linking agent, the structural formula of which is shown below:

[0045] in:

[0046] The preparation method of the above-mentioned guaiacol-based organic amine cross-linking agent is as follows:

[0047] 12.4 g of guaiacol, 6.0 g of paraformaldehyde, 21.0 g of diethanolamine and 0.5 g of p-toluenesulfonic acid were added to a three-necked flask, heated to 80°C, and kept warm for 6 hours after the temperature stabilized. Water and unreacted small molecules were removed by vacuum distillation to obtain a guaiacol-based organic amine crosslinker. Its characterization infrared spectrum and hydrogen spectrum can be found in Figure 1 and Figure 2 .

[0048] Example 2

[0049] The embodiment of the present invention provides a guaiacol-based organic amine cross-linking agent, the structural formula of which is shown below:

[0050] in:

[0051] The preparation method of the above-mentioned guaiacol-based organic amine cross-linking agent is as follows:

[0052] 12.4 g of guaiacol, 6.0 g of paraformaldehyde, 15.0 g of monoisopropanolamine and 0.8 g of magnesium chloride were added into a three-necked flask, and the temperature was raised to 90° C. After the temperature stabilized, the mixture was kept warm for 7 hours, and water and unreacted small molecules were removed by distillation under reduced pressure to obtain a guaiacol-based organic amine cross-linking agent.

[0053] Example 3

[0054] The embodiment of the present invention provides a guaiacol-based organic amine cross-linking agent, the structural formula of which is shown below:

[0055] in:

[0056] The preparation method of the above-mentioned guaiacol-based organic amine cross-linking agent is as follows:

[0057] 12.4 g of guaiacol, 6.0 g of paraformaldehyde, 39.9 g of diisopropanolamine and 0.2 g of concentrated sulfuric acid were added into a three-necked flask, and the temperature was raised to 80° C. After the temperature stabilized, the reaction was kept warm for 10 hours, and water and unreacted small molecules were removed by vacuum distillation to obtain a guaiacol-based organic amine cross-linking agent.

[0058] Example 4

[0059] The embodiment of the present invention provides a guaiacol-based organic amine cross-linking agent, the structural formula of which is shown below:

[0060] in:

[0061] The preparation method of the above-mentioned guaiacol-based organic amine cross-linking agent is as follows:

[0062] 12.4 g of guaiacol, 9.0 g of paraformaldehyde, 24.2 g of tris(hydroxymethyl)aminomethane and 0.5 g of p-toluenesulfonic acid were added into a three-necked flask, and the temperature was raised to 80° C. After the temperature stabilized, the mixture was kept warm for 3 h, and water and unreacted small molecules were removed by distillation under reduced pressure to obtain a guaiacol-based organic amine cross-linking agent.

[0063] Example 5

[0064] The embodiment of the present invention provides a guaiacol-based organic amine cross-linking agent, the structural formula of which is shown below:

[0065] in:

[0066] The preparation method of the above-mentioned guaiacol-based organic amine cross-linking agent is as follows:

[0067] 12.4 g of guaiacol, 6.0 g of paraformaldehyde, 39.0 g of N-hydroxyethylpiperazine and 0.4 g of zinc chloride were added into a three-necked flask, and the temperature was raised to 60° C. After the temperature stabilized, the mixture was kept warm for 6 hours, and water and unreacted small molecules were removed by distillation under reduced pressure to obtain a guaiacol-based organic amine cross-linking agent.

[0068] Example 6

[0069] The embodiment of the present invention provides a guaiacol-based organic amine cross-linking agent, the structural formula of which is shown below:

[0070] in:

[0071] The preparation method of the above-mentioned guaiacol-based organic amine cross-linking agent is as follows:

[0072] Add 12.4 g of guaiacol, 6.0 g of paraformaldehyde, 15.0 g of methylethanolamine and 0.4 g of boron trifluoride ether into a three-necked flask, heat to 70°C, keep the temperature for 4 hours after the temperature stabilizes, and remove water and unreacted small molecules by distillation under reduced pressure to obtain a guaiacol-based organic amine cross-linking agent.

[0073] Example 7

[0074] The embodiment of the present invention provides a guaiacol-based organic amine cross-linking agent, the structural formula of which is shown below:

[0075] in:

[0076] The preparation method of the above-mentioned guaiacol-based organic amine cross-linking agent is as follows:

[0077] 12.4 g of guaiacol, 6.0 g of polyformaldehyde, 18.2 g of 2-amino-1,3-propanediol and 1.0 g of phosphoric acid were added into a three-necked flask, heated to 100° C., and kept warm for 8 hours after the temperature stabilized. Water and unreacted small molecules were removed by reduced pressure distillation to obtain a guaiacol-based organic amine cross-linking agent.

[0078] Comparative Examples 1-5

[0079] Comparative Example 1: trimethylolpropane; Comparative Example 2: triethanolamine; Comparative Example 3: glycerol; Comparative Example 4: ethylene glycol; Comparative Example 5: p-hydroxyphenylethanol.

[0080] Application Examples

[0081] The crosslinking agents of Examples 1-7 and Comparative Examples 1-5 are used to prepare polyurethane molded foam. Specifically, the polyurethane molded foam is prepared by reacting component X and component Y. The preparation method is as follows:

[0082] Preparation of component X: According to the formula in Table 1, the weighed polyether polyol, surfactant, catalyst, water, and crosslinking agent were mixed and stirred at room temperature for 20 seconds at a speed of 2000 r / min.

[0083] Table 1X Component Formula

[0084]

[0085]

[0086] The Y component is TM-20.

[0087] When the raw material temperature is 20-25°C, add component X and component Y according to 96% of isocyanate number, stir for 5s at 2000r / min, and introduce into the mold after mixing evenly. The mold temperature is 50-70°C and the mold clamping pressure is 1.0-5.0bar. Foam is formed after aging for 5 minutes. Take out the foam and conduct performance test.

[0088] The standard square mold exhaust force test method is referenced to: GBT10807-2006 Determination of hardness of flexible foam polymer materials (indentation method). Other test methods are referenced to: QBT 2080-2010 High resilience flexible polyurethane foam plastics. The structure is shown in Table 2.

[0089] Table 2 Test results

[0090]

[0091] As can be seen from Table 2, when the cross-linking agent prepared in the embodiment of the present invention is applied to high-resilience molded foam, compared with the foam prepared by the cross-linking agent of Comparative Examples 1-5, it has less inflation, making the foam have better easy opening (refer to the standard square mold exhaust force data), higher support (refer to 65% depression hardness and 25% depression hardness data), and the tensile strength, tensile elongation, resilience and comfort factor of the foam are equivalent. The partial introduction of different types of cross-linking agents has been correspondingly optimized from the performance perspective. It can be seen that the guaiacol-based organic amine cross-linking agent provided in the embodiment of the present invention can effectively improve the performance of the foam.

[0092] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A guaiacol-based organic amine cross-linking agent, It is characterized in that It is selected from the compounds represented by the following structural formula: Among them, R 1 Selected from R 2 and R 3 are independently selected from hydrogen, C1-C5 unsubstituted alkyl and hydroxy-substituted C2-C5 alkyl, and R 2 and R 3 At least one of them is a C2-C5 alkyl group substituted with a hydroxyl group; Represents a 5-7 membered ring; R 4 N or C, R 5 It represents a C2-C5 alkyl group substituted with a hydroxy group.

2. The guaiacol-based organic amine cross-linking agent according to claim 1, It is characterized in that R 1 Selected from R 2 and R 3 are independently selected from hydrogen, C1-C5 unsubstituted alkyl and hydroxy-substituted C2-C5 alkyl, and R 2 and R 3 At least one of them is a C2-C5 alkyl group substituted with a hydroxyl group; 5 It represents a C2-C5 alkyl group substituted with a hydroxy group.

3. The guaiacol-based organic amine cross-linking agent according to claim 1, It is characterized in that R 1 Any one selected from the groups shown in the following structural formulas:

4. A method for preparing the guaiacol-based organic amine cross-linking agent according to claim 1, It is characterized in that include: Guaiacol, an amine compound and paraformaldehyde are mixed to react.

5. The preparation method according to claim 4, It is characterized in that include: The guaiacol, the amine compound, the polyformaldehyde and the catalyst are mixed at 60-120° C. and reacted for 2-10 hours.

6. The preparation method according to claim 5, It is characterized in that The molar ratio of the guaiacol, the amine compound and the paraformaldehyde is 1:(1-5):(1-3).

7. The preparation method according to claim 5, It is characterized in that The amount of the catalyst used is 0.1-3 wt%.

8. The preparation method according to claim 5, It is characterized in that The amine compound is selected from any one of diisopropanolamine, N-hydroxyethylpiperazine, diethanolamine, methylethanolamine, monoisopropanolamine, tris(hydroxymethyl)aminomethane and 2-amino-1,3-propylene glycol.

9. The preparation method according to claim 5, It is characterized in that The catalyst is any one of p-toluenesulfonic acid, acetic acid, concentrated sulfuric acid, phosphoric acid, fluoroboric acid, boron trifluoride etherate, boron trifluoride acetic acid, zinc chloride, aluminum chloride, magnesium chloride and ferric chloride.

10. A polyurethane foam, It is characterized in that The cross-linking agent is prepared by using the guaiacol-based organic amine cross-linking agent described in claim 1.

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