Low viscosity aniline polyether polyols, their preparation methods and applications

Abstract

This invention belongs to the field of polyether polyol technology, specifically relating to low-viscosity aniline polyether polyol, its preparation method, and its application. The low-viscosity aniline polyether polyol has a viscosity below 10000 mPa·s, and its raw material components include 5-15 parts of o-toluene diamine, 10-35 parts of aniline compound, 0.05-0.3 parts of alkali metal catalyst, and 30-70 parts of epoxide alkane. The resulting low-viscosity aniline polyether polyol has even lower viscosity, resulting in better operability and applicability in product applications, and exhibits excellent thermal conductivity in the preparation of rigid polyurethane foam products. The preparation method is simple and convenient. The application of the low-viscosity aniline polyether polyol is in the preparation of rigid polyurethane foam.

Description

Technical Field

[0001] This invention belongs to the field of polyether polyol technology, specifically relating to low-viscosity aniline polyether polyols, their preparation methods, and applications. Background Technology

[0002] Rigid polyurethane foam possesses excellent thermal insulation properties, high strength, and superior electrical, chemical resistance, and sound insulation performance. It is also easy to process and mold, making it widely used in building insulation, petrochemical pipeline transportation, and home appliances. o-Tolyldiamine polyether, prepared using o-tolyldiamine as an initiator, exhibits good miscibility with pentane, resulting in foams with good dimensional stability and fine pores. It effectively reduces the thermal conductivity of the foam, making it an essential component in high-end composite materials for home appliances and playing an irreplaceable role in low-thermal-conductivity applications. Its application has now expanded to many other fields, including containers and sheet materials. However, as o-tolyldiamine is a solid initiator, the polyether prepared from it typically has a high viscosity, which presents significant inconvenience in practical applications.

[0003] To reduce the viscosity of o-tolyldiamine polyether, the industry typically adds an alkali metal catalyst at the initial stage of the reaction. Chinese patent CN108129648A discloses a toluenediamine polyether polyol and its preparation method. This method includes the following steps: mixing toluenediamine and an alkaline catalyst; adding an epoxide compound to initiate a ring-opening polymerization reaction under polymerization temperature and pressure; followed by a ripening reaction; after ripening, cooling, degassing, and neutralization with water and acid. While this method can reduce the viscosity of o-tolyldiamine polyether, the addition of an alkali metal catalyst at the initial stage significantly increases the irregularity of the product's molecular structure. This can lead to stratification with other components when formulating polyether blends in downstream applications, greatly reducing product stability.

[0004] Another method to reduce viscosity during the preparation of polyether polyols is to add triethanolamine as a composite initiator. Although this method can effectively reduce the viscosity of o-toluene diamine polyether, it will also reduce the thermal conductivity of the product. Summary of the Invention

[0005] To address the shortcomings of existing technologies, the present invention aims to provide a low-viscosity aniline polyether polyol. Using aniline compounds as composite initiators, the resulting polyether polyol has a lower viscosity, resulting in better operability and applicability in product applications. This leads to the excellent thermal conductivity of rigid polyurethane foam products prepared in this way.

[0006] Another objective of this invention is to provide a method for preparing and applying a low-viscosity aniline polyether polyol. The preparation method is simple and easy to operate. The application of the low-viscosity aniline polyether polyol is for the preparation of rigid polyurethane foam.

[0007] The technical solution adopted in this invention is as follows:

[0008] The low-viscosity aniline polyether polyol is composed of the following raw materials in parts by weight:

[0009]

[0010]

[0011] The aniline compound is one or more of mesitylene trimethylaniline and o-methoxyaniline.

[0012] The alkali metal catalyst is one or more of potassium hydroxide and sodium hydroxide, preferably potassium hydroxide.

[0013] The epoxide hydrocarbon is one or more of ethylene oxide, butane oxide, propylene oxide, or epichlorohydrin.

[0014] The method for preparing the low-viscosity aniline polyether polyol includes the following steps:

[0015] (1) Add o-toluenediamine and aniline compound to the reactor, replace with nitrogen, evacuate and stir to raise the temperature to the specified temperature, slowly add some epoxy alkane to the reactor to carry out the polymerization reaction, control the temperature and reaction pressure until the reaction time ends, and obtain intermediate product.

[0016] (2) After adding an alkali metal catalyst to the intermediate product obtained in step (1), the remaining epoxy alkane is slowly added after vacuuming to carry out the polymerization reaction. The temperature and reaction pressure are controlled until the reaction time ends to obtain crude aniline polyether polyol. Then, it is purified to obtain low viscosity aniline polyether polyol.

[0017] The viscosity of the low-viscosity aniline polyether polyol is less than 10,000 mPa·s.

[0018] In step (1), the amount of alkyl oxidants used accounts for 60 wt.% to 90 wt.% of the total amount of alkyl oxidants used.

[0019] In steps (1) and (2), the polymerization reaction temperature is 100-130℃, the pressure when adding the epoxide is -0.09--0.06 MPa, the polymerization reaction pressure is 0.1-0.25 MPa, and the time is 0.5-5 h.

[0020] The refining process in step (2) includes neutralization, adsorption, drying, and filtration.

[0021] The refining process in step (2) is as follows: add a mixture of phosphoric acid and pure water to the obtained crude aniline polyether polyol, stir at 80-90°C for 0.5-1h for neutralization; after neutralization, add an adsorbent, stir at 80-90°C for 0.5-1h for adsorption; after adsorption, dehydrate and dry; after drying, filter under reduced pressure to obtain low viscosity aniline polyether polyol.

[0022] The aforementioned low-viscosity aniline polyether polyol is used to prepare rigid polyurethane foam.

[0023] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0024] (1) This invention uses liquid aniline compound and solid o-toluenediamine as a composite initiator, which greatly reduces the viscosity of o-toluenediamine polyether, improves the practicality and applicability, and has excellent processing performance, especially suitable for preparing rigid polyurethane foam.

[0025] (2) The liquid aniline compound used in this invention is highly similar in structure to o-toluenediamine. The rigid polyurethane foam prepared with the low viscosity aniline polyether polyol obtained in this invention has no loss in thermal conductivity compared with the pure o-toluenediamine polyether product prepared with o-toluenediamine as the initiator.

[0026] (3) By using the preparation method described in this invention, the viscosity of o-toluene diamine polyether was successfully reduced while ensuring performance, thus solving the operational and applicability problems caused by the excessively high viscosity of o-toluene diamine polyether in the industry. Detailed Implementation

[0027] The present invention will be further described below with reference to the embodiments, but these embodiments do not limit the implementation of the present invention; the raw materials used in the embodiments and comparative examples are all commercially available conventional raw materials unless otherwise specified.

[0028] The raw materials and their amounts (g) in the examples and comparative examples are shown in Table 1:

[0029] Table 1

[0030] project Example 1 Example 2 Example 3 o-Toluenediamine 100 100 100 Trimethylaniline 200 / 200 o-Methoxyaniline / 125 / potassium hydroxide 2.5 2.1 / Sodium hydroxide / / 0.43 propylene oxide 600 / / Ethylene oxide / 520 / epichlorohydrin / / 575

[0031] Example 1

[0032] (1) 100g of o-toluenediamine and 200g of mesitylenediamine were added to the reactor in sequence, stirring was started, nitrogen was used for purging, and after pressure testing, the reactor was evacuated to -0.09MPa and the temperature was raised to 130℃. 360g of propylene oxide was slowly added to the reactor to carry out the polymerization reaction. During the reaction, the pressure was maintained at 0.2MPa. The reaction was continued for 3 hours at this temperature and pressure to obtain the intermediate product.

[0033] (2) Add 2.5g of solid potassium hydroxide to the intermediate product obtained in step (1), evacuate the reactor to -0.09MPa, slowly add 240g of propylene oxide, maintain the pressure at 0.2MPa, and continue the reaction at this temperature and pressure for 2h to obtain crude aniline polyether polyol. Then, refine it by adding a mixed solution of 9g phosphoric acid and 60g pure water to the crude aniline polyether polyol and stirring at 80℃ for 1h for neutralization. After neutralization, add 1.4g magnesium silicate and 0.7g aluminum silicate adsorbent and stir at 90℃ for 1h for adsorption. After adsorption, dehydrate and dry for 2.5h. After drying, filter under reduced pressure to obtain low viscosity aniline polyether polyol.

[0034] Example 2

[0035] (1) 100g of o-toluenediamine and 125g of o-methoxyaniline were added to the reactor in sequence, stirring was started, nitrogen was used for purging, and after pressure testing, the reactor was evacuated to -0.09MPa and the temperature was raised to 100℃. 380g of ethylene oxide was slowly added to the reactor to carry out the polymerization reaction. During the reaction, the pressure was maintained at 0.25MPa. The reaction was continued at this temperature and pressure for 5 hours to obtain the intermediate product.

[0036] (2) Add 2.1g of solid potassium hydroxide to the intermediate product obtained in step (1), evacuate the reactor to -0.09MPa, slowly add 140g of ethylene oxide, maintain the pressure at 0.25MPa, and continue the reaction at this temperature and pressure for 2h to obtain crude aniline polyether polyol, and then perform purification treatment. Add 5g of phosphoric acid and 40g of pure water mixed solution to the obtained crude aniline polyether polyol, stir at 85℃ for 1h for neutralization treatment; after neutralization, add 0.8g of magnesium silicate and 0.4g of aluminum silicate adsorbent, stir at 85℃ for 0.5h for adsorption treatment; after adsorption, dehydrate and dry for 2.5h; after drying, filter under reduced pressure to obtain low viscosity aniline polyether polyol.

[0037] Example 3

[0038] (1) 100g of o-toluenediamine and 200g of mesitylenediamine were added to the reactor in sequence, stirring was started, nitrogen was used for purging, and after pressure testing, the reactor was evacuated to -0.09MPa and the temperature was raised to 110℃. 515g of epichlorohydrin was slowly added to the reactor to carry out the polymerization reaction. During the reaction, the pressure was maintained at 0.1MPa. The reaction was continued at this temperature and pressure for 4 hours to obtain the intermediate product.

[0039] (2) Add 0.43g of solid sodium hydroxide to the intermediate product obtained in step (1), evacuate the reactor to -0.09MPa, slowly add 60g of epichlorohydrin, maintain the pressure at 0.1MPa, and continue the reaction at this temperature and pressure for 0.5h to obtain crude aniline polyether polyol, and then perform purification treatment. Add 17g of phosphoric acid and 50g of pure water mixed solution to the obtained crude aniline polyether polyol, stir at 90℃ for 0.5h for neutralization treatment; after neutralization, add 1g of magnesium silicate and 0.5g of aluminum silicate adsorbent, stir at 90℃ for 0.5h for adsorption treatment; after adsorption, dehydrate and dry for 2.5h; after drying, filter under reduced pressure to obtain low viscosity aniline polyether polyol.

[0040] Comparative Example 1

[0041] (1) Add 100g of o-toluenediamine to the reactor, start stirring, replace with nitrogen, pressurize and test for leaks, then evacuate the reactor to -0.09MPa, raise the temperature to 130℃, slowly introduce 220g of propylene oxide, carry out the polymerization reaction, maintain the pressure at 0.2MPa during the reaction, and continue the reaction at this temperature and pressure for 3h to obtain the intermediate product.

[0042] (2) Add 3.9g of solid potassium hydroxide to the intermediate product obtained in step (1), evacuate the reactor to -0.09MPa, slowly introduce 140g of propylene oxide, maintain the pressure at 0.2MPa, and continue the reaction at this temperature and pressure for 2h to obtain crude polyether polyol. Finally, add 9g of phosphoric acid and 60g of pure water mixed solution at 80℃ for neutralization reaction. After reacting for 1h, add 1.4g of magnesium silicate and 0.7g of aluminum silicate adsorbent, stir for 30min and then dehydrate and dry for 2.5h. After drying, filter to obtain polyether polyol.

[0043] Comparative Example 2

[0044] (1) 100g of o-toluenediamine and 70g of triethanolamine were added to the reactor in sequence, stirring was started, nitrogen was used for purging, and after pressure testing, the reactor was evacuated to -0.09MPa and the temperature was raised to 130℃. 300g of propylene oxide was slowly introduced to carry out the polymerization reaction. During the reaction, the pressure was maintained at 0.2MPa. The reaction was continued for 3 hours at this temperature and pressure to obtain the intermediate product.

[0045] (2) Add 3g of solid potassium hydroxide to the intermediate product obtained in step (1), evacuate the reactor to -0.09MPa, slowly introduce 200g of propylene oxide, maintain the pressure at 0.2MPa, and continue the reaction at this temperature and pressure for 2h to obtain crude polyether polyol. Finally, add 7g of phosphoric acid and 40g of pure water mixed solution at 80℃ for neutralization reaction. After reacting for 1h, add 1.4g of magnesium silicate and 0.7g of aluminum silicate adsorbent, stir for 30min and then dehydrate and dry for 2.5h. After drying, filter to obtain polyether polyol.

[0046] Comparative Example 3

[0047] (1) Add 100g of o-toluenediamine and 0.5g of solid potassium hydroxide to the reactor, start stirring, replace with nitrogen, pressurize and test for leaks, then evacuate the reactor to -0.09MPa, raise the temperature to 130℃, slowly introduce 220g of propylene oxide to carry out the polymerization reaction, maintain the pressure at 0.2MPa during the reaction, and continue the reaction at this temperature and pressure for 3h to obtain the intermediate product;

[0048] (2) Add 3.9g of solid potassium hydroxide to the intermediate product obtained in step (1), evacuate the reactor to -0.09MPa, slowly introduce 140g of propylene oxide, maintain the pressure at 0.2MPa, and continue the reaction at this temperature and pressure for 2 hours to obtain crude polyether polyol. Finally, add a mixed solution of 9g phosphoric acid and 60g pure water at 80℃ for neutralization reaction. After reacting for 1 hour, add 1.4g magnesium silicate and 0.7g aluminum silicate adsorbent, stir for 30 minutes, and then dehydrate and dry for 2.5 hours. After drying, filter to obtain polyether polyol.

[0049] Detection method:

[0050] The performance of the polyether polyols prepared in Examples 1-3 and Comparative Examples 1-3 was tested according to GB / T 12008.3-1989 and GB / T 12008.7-2010, respectively. The test results are shown in Table 2.

[0051] Table 2 Performance Test Results

[0052]

[0053] The test data above show that, compared with Comparative Example 1, which used o-toluenediamine as a single initiator, the viscosity of the polyether polyols prepared in Examples 1-3 was reduced to below 10000 mPa·s, and even reached 6100 mPa·s. Comparative Example 2 used o-toluenediamine and triethanolamine as a composite initiator, and Comparative Example 3 added an alkali metal catalyst at the initial stage of the reaction. Although these measures reduced viscosity, the reduction was limited. This demonstrates that the method for preparing low-viscosity aniline polyether polyols described in this invention significantly reduces the viscosity of the resulting low-viscosity aniline polyether polyols, greatly increasing their operability and applicability in downstream applications, exhibiting excellent processing performance, and being easy to use.

[0054] The polyether polyols obtained in Examples 1-3 and Comparative Examples 1-3 were formulated according to the formulation shown in Table 3, and rigid polyurethane foam products were obtained by the following preparation method. The thermal conductivity of the products was tested, and the test results are shown in Table 4.

[0055] Table 3. Rigid polyurethane foam sample preparation formula

[0056] raw material Number of copies Aniline polyether polyols 70 INOVOL R6207 30 <![CDATA[H2O]]> 1.5 N,N-Dimethylcyclohexylamine 1 BDMA 0.5 cyclopentane 20 TEGOSTAB B8460 3

[0057] Preparation method of rigid polyurethane foam sample: Under the conditions of ambient temperature of 25℃ and mold temperature of 45℃, accurately weigh the materials according to the formula in Table 3 and prepare the composite material in a 500mL beaker. Take 50 parts of the above composite material and 60 parts of isocyanate PM200 and stir thoroughly. Stop stirring when the system is uniform. Pour the stirred material into a constant temperature foaming mold. After the foam has foamed, matured and cured, remove it from the mold to obtain a rigid polyurethane foam sample.

[0058] The testing standards and methods used for rigid polyurethane foam samples are as follows:

[0059] Thermal conductivity: The rigid polyurethane foam obtained above was cut into samples with dimensions of 20×20×2.5 (cm) and thermal conductivity was tested. The test method was GB / T 10295-2008 "Determination of steady-state thermal resistance and related properties of thermal insulation materials by heat flow meter method".

[0060] Table 4. Test results of thermal conductivity of rigid polyurethane foam

[0061]

[0062] As shown in Tables 2 and 4, while the viscosity of the polyether polyol product using o-tolyldiamine and triethanolamine as composite initiators in Comparative Example 2 was effectively reduced compared to the product using pure o-tolyldiamine as an initiator, it resulted in a significant loss in the thermal conductivity of the final product. In Comparative Example 3, the addition of an alkali metal catalyst at the initial stage of the reaction reduced viscosity, but caused raw material stratification during the preparation of rigid polyurethane foam, resulting in poor stability. The polyether polyol product obtained by the present invention using composite aniline initiators showed a significant reduction in viscosity compared to the two aforementioned polyether polyol products. The thermal conductivity of the product in Example 1 was essentially the same as that of the polyether polyol product using pure o-tolyldiamine as an initiator. The thermal conductivity of the products in Examples 2 and 3 was significantly improved, greatly increasing the operability and applicability for downstream applications, and the thermal conductivity and stability of the final rigid polyurethane foam were not compromised.

Claims

1. A low-viscosity aniline polyether polyol, characterized in that, It consists of the following raw materials in parts by weight: 5-15 parts of o-toluenediamine; 10-35 parts of aniline compound; Alkali metal catalyst, 0.05-0.3 parts; 30-70 parts of epoxides; The aniline compound is one or both of mesitylene and o-methoxyaniline; The method for preparing the low-viscosity aniline polyether polyol includes the following steps: (1) Add o-toluenediamine and aniline compound to a reaction vessel, add some epoxy alkane, and carry out polymerization reaction to obtain intermediate product; (2) After adding an alkali metal catalyst to the intermediate product obtained in step (1), the remaining epoxy alkane is added to carry out a polymerization reaction to obtain crude aniline polyether polyol, which is then purified to obtain low viscosity aniline polyether polyol. In step (1), the amount of epoxide alkane used accounts for 60 wt.% to 90 wt.% of the total amount of epoxide alkane used.

2. The low viscosity aniline polyether polyol according to claim 1, characterized in that, The alkali metal catalyst is one or more of potassium hydroxide and sodium hydroxide.

3. The low viscosity aniline polyether polyol according to claim 1, characterized in that, The epoxide hydrocarbon is one or more of ethylene oxide, butane oxide, propylene oxide, or epichlorohydrin.

4. The low viscosity aniline polyether polyol according to claim 1, characterized in that, In steps (1) and (2), the polymerization reaction temperature is 100~130℃, the polymerization reaction pressure is 0.1~0.25Mpa, and the time is 0.5~5h.

5. The low viscosity aniline polyether polyol according to claim 1, characterized in that, The refining process in step (2) includes neutralization, adsorption, drying, and filtration.

6. The application of the low-viscosity aniline polyether polyol according to any one of claims 1 to 5, characterized in that, Used to prepare rigid polyurethane foam.

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