A cashew phenol quaternary ammonium salt compound and its preparation method, a catalyst for rigid polyurethane foam, and rigid polyurethane foam.

Abstract

This invention discloses a cashew phenol quaternary ammonium salt compound and its preparation method, a catalyst for rigid polyurethane foam, and rigid polyurethane foam itself. The structure of the cashew phenol quaternary ammonium salt compound is shown below: n is 0-4. The cashew phenol quaternary ammonium salt contains an ester group, which improves compatibility with pentane, and the introduction of the ester group can reduce the thermal conductivity and increase the oxygen index; simultaneously, each molecule contains two tertiary amine structures, resulting in better catalytic effect per unit mass / molarity, i.e., higher catalytic efficiency. The cashew phenol quaternary ammonium salt compound can serve as a novel catalyst for rigid polyurethane foam. Compared with traditional polyurethane amine catalysts, its application in the field of rigid polyurethane foam has advantages such as safety, environmental friendliness, economy, high efficiency, and odorlessness.

Description

Technical Field

[0001] This invention belongs to the field of organic synthesis technology, specifically, it relates to a cashew phenol quaternary ammonium salt compound and its preparation method, and also relates to the field of polyurethane, specifically to rigid polyurethane foam. Background Technology

[0002] Through long-term research and practice, it has been found that tertiary amine catalysts and organotin catalysts are the most important catalysts in polyurethane production. However, the polyurethane foaming process is exothermic, and amine catalysts, due to their volatility, often produce irritating odors during foaming. Furthermore, amine catalysts possess a certain degree of toxicity. Given that polyurethane foam applications now permeate all aspects of life, developing an amine catalyst with low toxicity, low volatility, and low odor has broad market prospects.

[0003] Huo Shuping et al. (Forest Products Chemistry and Industry, Vol. 37, No. 2, pp. 115-120) used cashew phenol and lignin as raw materials, first modifying them with epichlorohydrin, and then reacting them with diethanolamine to prepare a highly active polyether polyol with tertiary amine groups. This polyether polyol can be used as a self-catalytic polyether polyol in the synthesis of polyurethane foam. The addition of lignin can increase the foam strength, but the compatibility between lignin and polyether is very poor. When the amount of lignin added is too high, the viscosity of the foaming system increases, resulting in difficulties in foaming and uneven foam cell structure. The partial structural formula disclosed in CN201810478813.x contains hydroxyl groups, which can react with polymerized MDI and be continuously consumed. The amine structure with catalytic effect will be fixed in a certain position or surrounded by other structures and gradually lose its catalytic effect.

[0004] A novel catalyst needs to be developed for the preparation of polyurethane foam. Summary of the Invention

[0005] The first objective of this invention is to provide a cashew phenol quaternary ammonium salt compound.

[0006] A second objective of this invention is to provide a method for preparing the aforementioned cashew phenol quaternary ammonium salt compound.

[0007] The third objective of this invention is to provide an application of the aforementioned cashew phenol quaternary ammonium salt compound as a catalyst for rigid polyurethane foam and the rigid polyurethane foam itself.

[0008] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0009] A cashew phenol quaternary ammonium salt compound, the structure of which is shown in Formula I:

[0010]

[0011] Where n is 0 to 4, for example n = 0, 1, 2, 3 or 4.

[0012] A method for preparing the cashew phenol quaternary ammonium salt compound of the present invention includes the following steps:

[0013] (1) Cashew phenol, bromoacetyl bromide, dichloromethane and pyridine were reacted to prepare esterified product IV.

[0014]

[0015] (2) The esterification product IV is reacted with 1-alkyl-1H-imidazolium to prepare compound I, wherein the alkyl group is selected from methyl, ethyl, n-propyl, n-butyl or n-pentyl.

[0016] In step (1) of this invention, the reaction temperature is 20–25°C.

[0017] In step (1) of this invention, the reaction time is 3 to 5 hours.

[0018] Preferably, the molar ratio of cashew phenol to bromoacetyl bromide is 1:1 to 1:1.2, and more preferably 1:1.

[0019] The amount of pyridine used is 3 to 5 times the mass of cashew phenol.

[0020] As a preferred embodiment, in step (1) of the present invention, after the reaction is completed, separation is performed. The separation method can be a method known in the art, such as column chromatography. As a commonly used method, column chromatography is used, with silica gel as the stationary phase and petroleum ether / ethyl acetate system as the mobile phase.

[0021] Preferably, in step (2) of the present invention, the molar ratio of esterification product IV to 1-alkyl-1H-imidazole is 1:1 to 1:1.2, and more preferably the molar ratio is 1:1.

[0022] In step (2) of the present invention, the reaction temperature is 60-80℃ and the reaction time is 3-5h.

[0023] As a preferred embodiment, step (2) is performed under solvent-free conditions.

[0024] As a preferred embodiment, after step (2) of the present invention is completed, the product is dissolved in acetone at 30-40°C to prepare a saturated solution, cooled to 10°C, and recrystallized to obtain compound I.

[0025] The cashew phenol quaternary ammonium salt compounds described in this invention can be used as polyurethane catalysts.

[0026] A rigid polyurethane foam, prepared from the following raw materials: by weight parts

[0027]

[0028] The diethylene glycol polyether polyol A of this invention uses diethylene glycol as the initiator, propylene oxide as the polymerization unit, and has a hydroxyl value of 200–300 mg KOH / g, preferably 265–295 mg KOH / g.

[0029] The sucrose and glycerol polyether polyol B of the present invention has sucrose and glycerol as initiators, propylene oxide as the polymerization unit, a hydroxyl value of 300-400 mgKOH / g, preferably 345-375 mgKOH / g, and a functionality of 4.0-5.0, preferably 4.3-4.7.

[0030] The sorbitol polyether polyol C of the present invention has sorbitol as the initiator, propylene oxide as the polymerization unit, and a hydroxyl value of 200-300 mgKOH / g, preferably 230-260 mgKOH / g.

[0031] The glycerol polyether polyol D of the present invention has glycerol as the initiator, propylene oxide as the polymerization unit, and a hydroxyl value of 50-100 KOH / g, preferably 51-61 mg KOH / g.

[0032] The surfactant described in this invention is a silicone-based surfactant. Suitable examples include, but are not limited to, at least one of Evonik's B8496 and B8545 from Germany. These surfactants have strong foam-stabilizing properties and good stability, which is beneficial for preparing rigid polyurethane foams with uniform cell structure.

[0033] The composite catalyst of the present invention comprises cashew phenol quaternary ammonium salt compound I of the present invention, and in addition, contains one or more of the following catalysts: pentamethyldiethylenetriamine, triethylenediamine, dimethylethanolamine, N,N-dimethylcyclohexylamine, triethylenediamine, triethylamine, N-methylpyrrolidone, 1,4-dimethylpiperazine, N,N-dimethylbenzylamine, dimethylaminoethyl ether, tris(dimethylaminopropyl)hexahydrotriazine, potassium acetate, potassium isooctanoate, stannous octanoate, TMR-2, cashew phenol quaternary ammonium salt, preferably triethylenediamine, N,N-dimethylcyclohexylamine, pentamethyldiethylenetriamine, hexahydrotriazine, TMR-2, and potassium acetate.

[0034] As a preferred embodiment, the composite catalyst of the present invention comprises a milky white catalyst, a gel catalyst, and a trimerizing catalyst, and a reasonable combination can ensure a stable reaction. Preferably, the milky white catalyst is pentamethyldiethylenetriamine, the gel catalyst is N,N-dimethylcyclohexylamine, and the trimerizing catalyst is cashew phenol quaternary ammonium salt.

[0035] As a preferred embodiment, the composite catalyst of the present invention is composed of pentamethyldiethylenetriamine: N,N-dimethylcyclohexylamine: cashew phenol quaternary ammonium salt in a mass ratio of 1-1.2: 0.24-0.3: 0.7-1.0.

[0036] In the polyurethane rigid foam of the present invention, as a preferred embodiment, the cashew phenol quaternary ammonium salt is provided in the form of a diethylene glycol solution, wherein the concentration of the cashew phenol quaternary ammonium salt in the solution is 40 wt% to 50 wt%.

[0037] The isocyanate described in this invention is polymeric MDI (polymethylene polyphenyl polyisocyanate) with an NCO content of 30-32%. Examples of polymeric isocyanates that can be used include, but are not limited to, one or more of PM-200, PM-400, and PM-700 from Wanhua Chemical Group Co., Ltd.

[0038] The cashew phenol quaternary ammonium salt of the present invention contains an ester group, which has better compatibility with pentane, and the introduction of the ester group can reduce the thermal conductivity and increase the oxygen index; at the same time, the cashew phenol quaternary ammonium salt of the present invention also has two tertiary amine structures in one molecule, which has better catalytic effect per unit mass / molarity, that is, higher catalytic efficiency.

[0039] The cashew phenol quaternary ammonium salt of this invention is simple to synthesize, non-toxic, harmless, and has a low odor. It uses inexpensive natural cashew phenol as a raw material and does not produce any environmentally harmful byproducts during synthesis. Results from free bubble reactivity, uplift curves, and polyurethane foam performance show that the catalytic effect of the cashew phenol quaternary ammonium salt is essentially consistent with that of the traditional laboratory catalyst TMR-2. Compared with traditional polyurethane amine catalysts, the cashew phenol quaternary ammonium salt has significant advantages in terms of odor, catalytic efficiency, safety, environmental friendliness, and economy. Detailed Implementation

[0040] To more clearly illustrate the present invention, the following description, in conjunction with preferred embodiments, further clarifies the invention. Those skilled in the art should understand that the specific descriptions below are illustrative rather than restrictive, and should not be construed as limiting the scope of protection of the present invention.

[0041] Experimental methods in the following examples, unless otherwise specified, were generally performed according to national standards. If no corresponding national standard exists, they were performed according to generally accepted international standards, standard conditions, or conditions recommended by the manufacturer. Unless otherwise stated, all parts are parts by weight, all percentages are weight percentages, and the molecular weights of the polymers are number-average molecular weights.

[0042] Unless otherwise defined or stated, all technical and scientific terms used herein have the same meaning as are familiar to those skilled in the art. Furthermore, any methods and materials similar to or equivalent to those described herein may be used in the methods of this invention.

[0043] All drugs mentioned in this patent are commercially available, and unless otherwise specified, they are all AR-pure, including:

[0044] Bromoacetyl bromide, dichloromethane, and pyridine were purchased from Shanghai Titan Technology Co., Ltd.

[0045] 1-Methyl-1H-imidazole, 1-ethyl-1H-imidazole, and cashew phenol were purchased from Shanghai Maclean Biochemical Technology Co., Ltd.

[0046] Diethylene glycol polyether polyol A, with diethylene glycol as the initiator, propylene oxide as the polymerization unit, and a hydroxyl value of 280 mg KOH / g.

[0047] Sucrose and glycerol polyether polyol B, with sucrose and glycerol as initiators, propylene oxide as the polymerization unit, and a hydroxyl value of 360 mg KOH / g.

[0048] Sorbitol polyether polyol C, with sorbitol as the initiator, propylene oxide as the polymerization unit, and a hydroxyl value of 245 mg KOH / g.

[0049] Glyceryl polyether polyol D, with glycerol as the initiator, propylene oxide as the polymerization unit, and a hydroxyl value of 56 mg KOH / g.

[0050] All of the above polyether polyols are produced by Wanhua Chemical (Ningbo) Rongwei.

[0051] Polymerized MDI (CP) was purchased from Wanhua Chemical.

[0052] Silicone oil B8496 was purchased from Evonik Specialty Chemicals Co., Ltd.

[0053] Pentamethyldiethylenetriamine, dimethylcyclohexylamine, and TMR-2 were purchased from Air Products.

[0054] Example 1

[0055] Preparation method of cashew phenol quaternary ammonium salt compound II:

[0056]

[0057] Cashew phenol (5 mmol) was placed in a 50 mL round-bottom flask, and 5 mmol of bromoacetyl bromide was added, followed by 5 mL of dichloromethane and pyridine. The reaction was carried out at room temperature for 4 hours. After the reaction was completed, the product was obtained by column chromatography. The esterified product and 1-methyl-1H-imidazole were added at a molar ratio of 1:1, and the mixture was refluxed at 70 °C for 3 hours without solvent. Recrystallization gave compound I (yield 86%).

[0058] Compound I, 1 H NMR(400MHz,DMSO)δ9.23(s,1H),7.86-7.87(m,1H), 7.80-7.81(m,1H),7.34-7.38(m,1H),7.02-7.14(m,3H),5.57(s,2H),3.95(s,3H), 2.57-2.61(t,J=8.0Hz,2H),1.53-1.55(m,2H),1.23-1.27(m,24H),0.83-0.87(t,J= 8.0Hz,3H).

[0059] 13C NMR (101MHz, DMSO) δ165.84,149.87,144.32,137.75,129.39,126.34,123.74,123.46, 120.99,118.56,49.74,36.00,34.77,31.26,30.71,29.01,28.68,28.58,22.07,13.92.

[0060] HRMS(ESI-TOF)m / z:[M-Br] + Calcd for C 27 H 43 N2O2 427.3325; Found 427.3333.

[0061] Example 2

[0062] Preparation method of cashew phenol quaternary ammonium salt compound III:

[0063]

[0064] Cashew phenol (5 mmol) was placed in a 50 mL round-bottom flask, and 5 mmol of bromoacetyl bromide was added, followed by 5 mL of dichloromethane and pyridine. The reaction was carried out at room temperature for 3 hours. After the reaction was completed, the product was obtained by column chromatography. The esterified product and 1-ethyl-1H-imidazol were added at a molar ratio of 1:1, and the mixture was refluxed at 70 °C for 3 hours without solvent. Recrystallization gave compound I (yield 82%).

[0065] Compound III, 1H NMR (400MHz, DMSO) δ9.33(s,1H),7.88-7.89(m,1H), 7.82-7.83(m,1H),7.37-7.40(m,1H),7.08-7.19(m,3H),5.57(s,2H),4.27 (m,J=7.1Hz 2H),2.59-2.63(t,J=8.0Hz,2H),1.54-1.55(m,2H),1.24-1.27(m,24H),0.92(t,J=7.4Hz,3H),0.83-0.86(t,J=8.0Hz,3H).

[0066] 13C NMR (101MHz, DMSO) δ165.81,149.89,144.27,137.82,129.41,126.30,12368,123.51,121. 02,118.59,49.77,35.95,34.81,31.22,30.67,28.98,28.72,28.63,22.12,15.05,13.98.

[0067] HRMS(ESI-TOF)m / z:[M-Br] + Calcd for C 28 H 45 N2O2 441.3402; Found 441.3410.

[0068] Example 3

[0069] Combination polyethers: Diethylene glycol polyether polyol A (hydroxyl value 280mgKOH / g) 13g, sucrose and glycerol polyether polyol B (hydroxyl value 360mgKOH / g) 57.71g, sorbitol polyether polyol C (hydroxyl value 245mgKOH / g) 15g, glycerol polyether polyol D (hydroxyl value 56mgKOH / g) 5g;

[0070] Surfactant: Silicone oil B8496 3g (Evonik);

[0071] Composite catalyst: foaming catalyst is 0.24g of pentamethyldiethylenetriamine, gel catalyst is 0.7g of dimethylcyclohexylamine, and trimerizing catalyst is 1g of cashew phenol quaternary ammonium salt of formula II (dissolved in diethylene glycol at a ratio of 1:1).

[0072] 4.35g of deionized water;

[0073] PM-200 160g.

[0074] The preparation method of rigid polyurethane foam includes the following steps:

[0075] 1) Weigh each raw material according to the ratio, put the combined polyether, surfactant, composite catalyst, water and foaming agent into a container, and mix them thoroughly to obtain the composite mixture;

[0076] 2) The obtained mixture is mixed with polyisocyanate, foamed under high pressure at a material temperature of 21°C and a pressure of 135 bar (gauge pressure). The filling coefficient of the reaction mixture in the mold is 1.15, and the demolding time is 360 s to obtain rigid polyurethane foam.

[0077] Example 4

[0078] Combination polyethers: Diethylene glycol polyether polyol A (hydroxyl value 280mgKOH / g) 13g, sucrose and glycerol polyether polyol B (hydroxyl value 360mgKOH / g) 57.71g, sorbitol polyether polyol C (hydroxyl value 245mgKOH / g) 15g, glycerol polyether polyol D (hydroxyl value 56mgKOH / g) 5g;

[0079] Surfactant: Silicone oil B8496 3g (Evonik);

[0080] Composite catalyst: foaming catalyst is 0.24g of pentamethyldiethylenetriamine, gel catalyst is 0.7g of dimethylcyclohexylamine, and trimerizing catalyst is 1g of cashew phenol quaternary ammonium salt of formula III (dissolved in diethylene glycol at a ratio of 1:1).

[0081] 4.35g of deionized water;

[0082] PM-200 160g.

[0083] The preparation method of rigid polyurethane foam includes the following steps:

[0084] 1) Weigh each raw material according to the ratio, put the combined polyether, surfactant, composite catalyst, water and foaming agent into a container, and mix them thoroughly to obtain the composite mixture;

[0085] 2) The obtained mixture is mixed with polyisocyanate, foamed under high pressure at a material temperature of 21°C and a pressure of 135 bar (gauge pressure). The filling coefficient of the reaction mixture in the mold is 1.15, and the demolding time is 360 s to obtain rigid polyurethane foam.

[0086] Comparative Example 1

[0087] Combination polyethers: Diethylene glycol polyether polyol A (hydroxyl value 280mgKOH / g) 13g, sucrose and glycerol polyether polyol B (hydroxyl value 360mgKOH / g) 57.71g, sorbitol polyether polyol C (hydroxyl value 245mgKOH / g) 15g, glycerol polyether polyol D (hydroxyl value 56mgKOH / g) 5g;

[0088] Surfactant: Silicone oil B8496 3g (Evonik);

[0089] Composite catalysts: foaming catalyst is 0.24g of pentamethyldiethylenetriamine, gel catalyst is 0.7g of dimethylcyclohexylamine, and trimerizing catalyst is 1g of TMR-2.

[0090] 4.35g of deionized water;

[0091] PM-200 160g.

[0092] The preparation method of rigid polyurethane foam includes the following steps:

[0093] 1) Weigh each raw material according to the ratio, put the combined polyether, surfactant, composite catalyst, water and foaming agent into a container, and mix them thoroughly to obtain the composite mixture;

[0094] 2) The obtained mixture is mixed with polyisocyanate, foamed under high pressure at a material temperature of 21°C and a pressure of 135 bar (gauge pressure). The filling coefficient of the reaction mixture in the mold is 1.15, and the demolding time is 360 s to obtain rigid polyurethane foam.

[0095] Comparative Example 2

[0096] Combination polyethers: Diethylene glycol polyether polyol A (hydroxyl value 280 mg KOH / g) 13g; Sucrose and glycerol polyether polyol B (hydroxyl value 360 ​​mg KOH / g) 57.71g; Sorbitol polyether polyol C (hydroxyl value 245 mg KOH / g) 15g; Glycerol polyether polyol D (hydroxyl value 56 mg KOH / g) 5g;

[0097] Surfactant: Silicone oil B8496 3g (Evonik);

[0098] Composite catalyst: The foaming catalyst is 0.24g of pentamethyldiethylenetriamine, the gelation catalyst is 0.7g of dimethylcyclohexylamine, and the trimerization catalyst is... (CN201810478813.x)1g.

[0099] 4.35g of deionized water;

[0100] PM-200 160g.

[0101] The preparation method of rigid polyurethane foam includes the following steps:

[0102] 1) Weigh each raw material according to the ratio, put the combined polyether, surfactant, composite catalyst, water and foaming agent into a container, and mix them thoroughly to obtain the composite mixture;

[0103] 2) The obtained mixture is mixed with polyisocyanate, foamed under high pressure at a material temperature of 21°C and a pressure of 135 bar (gauge pressure). The filling coefficient of the reaction mixture in the mold is 1.15, and the demolding time is 360 s to obtain rigid polyurethane foam.

[0104] The performance parameters of polyurethane rigid foams in Examples 3-4 and Comparative Examples 1-2 are shown in Table 1:

[0105] Table 1 Performance parameters of polyurethane rigid foam in Examples 3-4 and Comparative Examples 1-2

[0106]

[0107] Note: Foam density, compressive strength, and thermal conductivity were all measured according to national standards.

[0108] The foam core density test shall be conducted in accordance with the standard GB / T 6343-2009;

[0109] The thermal conductivity of foam was tested according to standard GB / T 10295-2008.

[0110] The foam compressive strength test shall be conducted in accordance with the standard GB / T 8813-2008;

[0111] Dimensional stability testing was conducted in accordance with standard GB / T 8811-2008.

[0112] Odor testing relies on subjective judgment using human sense of smell.

[0113] Through comparison of examples and comparative examples, compound II reacts slightly slower than TMR-2, but the difference is not significant. The resulting rigid polyurethane foam has essentially no difference in strength and thermal conductivity.

[0114] Compared with compound V (CN201810478813.x), compound II has a certain advantage in catalytic efficiency (using the same amount of catalyst, the filamentation time of compound II is 97s, while that of compound V is 119s), mainly because compound II contains more tertiary amine groups per unit amount.

[0115] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-described technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. A cashew phenol quaternary ammonium salt compound, the structure of which is shown in Formula I: ， in, n = 0, 1, 2, 3 or 4.

2. A method for preparing the cashew phenol quaternary ammonium salt compound according to claim 1, comprising the following steps: (1) Cashew phenol, bromoacetyl bromide, dichloromethane and pyridine were reacted to prepare esterified product IV. ； (2) The esterification product IV is reacted with 1-alkyl-1H-imidazolium, wherein the alkyl group is selected from methyl, ethyl, n-propyl, n-butyl or n-pentyl.

3. The method according to claim 2, characterized in that: In step (1), the reaction temperature is 20-25℃ and the reaction time is 3-5 hours.

4. The method according to claim 2, characterized in that, The molar ratio of cashew phenol to bromoacetyl bromide is 1:1 to 1:1.2; the amount of pyridine used is 3 to 5 times the mass of cashew phenol.

5. The method according to claim 2, characterized in that, In step (2), the molar ratio of esterification product IV to 1-alkyl-1H-imidazole is 1:1 to 1:1.

2.

6. The method according to claim 2, characterized in that, In step (2), the reaction temperature is 60-80℃ and the reaction time is 3-5h.

7. A catalyst for rigid polyurethane foam, comprising the cashew phenol quaternary ammonium salt compound as described in claim 1.

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