Phosphorus-containing organic thiourea catalyst and preparation method and application thereof, and bio-based block polyester polyol and preparation method and application thereof

Abstract

The invention belongs to the technical field of bio-based polyols, and particularly relates to a phosphorus-containing organic thiourea catalyst, a preparation method and application of the phosphorus-containing organic thiourea catalyst, bio-based block polyester polyol and a preparation method and application of the bio-based block polyester polyol. The phosphorus-containing organic thiourea catalyst provided by the invention has the characteristics of no metal, high catalytic activity, flame retardance, no need of removal and separation and the like. According to the invention, the castor oil, the aromatic ring-containing polyol and the phosphorus-containing organic thiourea catalyst are adopted, and the fatty acid chain segment of the castor oil is introduced into the molecular structure of the aromatic ring-containing polyol through selective transesterification; the bio-based block polyester polyol contains a saturated polyether chain segment, and the side group of the bio-based block polyester polyol is a fatty acid chain segment of castor oil. The bio-based block polyester polyol provided by the invention contains bifunctional and trifunctional aromatic ring chain segments, provides good acid and alkali resistance, heat resistance and wear resistance for the coating, has excellent chemical properties, especially chemical resistance, good mechanical properties and physical properties, and reliable comprehensive properties.

Description

Technical Field

[0001] The present invention belongs to the technical field of bio-based polyols, and specifically relates to a phosphorus-containing organic thiourea catalyst, a preparation method and application thereof, and a bio-based segmented polyester polyol, a preparation method and application thereof. Background Art

[0002] Concrete floors are susceptible to corrosion from factors such as carbonization and high loads, leading to structural damage and surface cracking. Floor coatings are an effective way to reduce or delay these damages. As a high-performance, multifunctional floor coating, polyurethane floor coatings offer advantages such as excellent elasticity, flexibility, crack resistance, weather resistance, anti-slip and wear resistance, and decorative properties, significantly extending the service life of concrete floors.

[0003] In order to reduce the consumption of non-renewable resources, researchers have developed bio-based raw materials for polyurethane floor coatings, such as castor oil, palm oil, soybean oil or cashew nut shell oil, to replace or partially replace petroleum-based raw materials - polyester polyols. These have the advantages of wide sources, renewability and low environmental pollution. However, the resulting polyurethane has poor acid and alkali resistance. Summary of the Invention

[0004] The purpose of the present invention is to provide a phosphorus-containing organic thiourea catalyst, a preparation method and application thereof, and a bio-based segmented polyester polyol, a preparation method and application thereof. The polyurethane prepared from the bio-based segmented polyester polyol provided by the present invention has good acid and alkali resistance and excellent chemical properties.

[0005] In order to achieve the above object, the present invention provides the following technical solutions:

[0006] The present invention provides a phosphorus-containing organic thiourea catalyst, the structure of which is shown in Formula I:

[0007]

[0008] The present invention also provides a method for preparing the phosphorus-containing organic thiourea catalyst described in the above scheme, comprising the following steps:

[0009] 3,5-bis(trifluoromethyl)phenylisothiocyanate, 2-(diphenylphosphino)ethylamine and a good solvent are mixed and sequentially subjected to a nucleophilic addition reaction, and then a trivalent phosphorus oxidation reaction is carried out under oxygen conditions to obtain the phosphorus-containing organic thiourea catalyst.

[0010] Preferably, the molar ratio of the 3,5-bis(trifluoromethyl)phenylisothiocyanate to 2-(diphenylphosphino)ethylamine is 1:1 to 1.05.

[0011] The present invention also provides the use of the phosphorus-containing organic thiourea catalyst described in the above scheme or the phosphorus-containing organic thiourea catalyst obtained by the preparation method described in the above scheme in an ester exchange reaction.

[0012] The present invention also provides a bio-based segmented polyester polyol, the structure of which is shown in Formula II:

[0013]

[0014] In formula II, Ar is

[0015] The average relative molecular mass of the bio-based segmented polyester polyol is 600-800 g / mol.

[0016] Preferably, the bio-based segmented polyester polyol has a hydroxyl value of 160 to 400 mg KOH / g, an acid value of ≤2 mg KOH / g, and a viscosity (25° C.) of 1000 to 3500 mPa.s.

[0017] The present invention also provides a method for preparing the bio-based segmented polyester polyol described in the above scheme, comprising the following steps:

[0018] A phosphorus-containing organic thiourea catalyst, an aromatic ring-containing polyol, and dry castor oil are mixed to undergo an ester exchange reaction to obtain the bio-based segmented polyester polyol; the phosphorus-containing organic thiourea catalyst is the phosphorus-containing organic thiourea catalyst described in the above scheme or the phosphorus-containing organic thiourea catalyst obtained by the preparation method described in the above scheme.

[0019] Preferably, the transesterification reaction is carried out in a protective atmosphere; the transesterification reaction includes a normal pressure transesterification stage and a vacuum transesterification stage in sequence; the temperature of the normal pressure transesterification stage is 80 to 180°C, and the insulation time is 5 to 10 hours; the temperature of the vacuum transesterification stage is 80 to 180°C, the vacuum degree is -100 to -80 kPa, and the insulation time is 2 to 5 hours.

[0020] The present invention also provides the use of the bio-based segmented polyester polyol described in the above scheme or the bio-based segmented polyester polyol obtained by the preparation method described in the above scheme in coatings.

[0021] The present invention also provides a polyurethane, wherein the polyester polyol raw material is the bio-based segmented polyester polyol described in the above scheme or the bio-based segmented polyester polyol obtained by the preparation method described in the above scheme.

[0022] The present invention provides a phosphorus-containing organic thiourea catalyst. The phosphorus-containing organic thiourea catalyst provided by the present invention contains two strongly electron-withdrawing trifluoromethyl groups and multiple benzene ring structures, has strong reactivity and a large steric hindrance effect, and can catalyze a directional single transesterification reaction between a polyol and castor oil triester, thereby obtaining castor oil diesters and castor oil segmented polyester polyol molecular structures, effectively reducing the generation of small molecule products such as glycerol and castor oil monoesters, thereby improving the performance and interpenetrating network structure of polyurethanes prepared from bio-based segmented polyester polyols. In addition, the phosphorus-containing organic thiourea catalyst provided by the present invention has the characteristics of being metal-free and having high catalytic activity, and the phosphorus-containing organic thiourea catalyst of the present invention has flame retardant properties, which greatly improves the safety of the products prepared by the catalytic preparation thereof; the phosphorus-containing organic thiourea catalyst of the present invention has high catalytic activity, and thus can be used in small amounts, has no effect on the subsequent preparation of polyurethane materials, and does not require removal or separation.

[0023] The present invention also provides a method for preparing the phosphorus-containing organic thiourea catalyst described in the above scheme. The preparation method provided by the present invention has simple steps, convenient operation, good safety, high feasibility, and is suitable for industrial production.

[0024] The present invention also provides the use of the phosphorus-containing organothiourea catalyst described in the above embodiment or the phosphorus-containing organothiourea catalyst obtained by the preparation method described in the above embodiment in an ester exchange reaction. The phosphorus-containing organothiourea catalyst provided by the present invention can be used to prepare polyurethane raw materials, especially bio-based segmented polyester polyols. The resulting bio-based segmented polyester polyols have high activity, are easy to react to form polyurethanes, have low molecular weight, excellent overall performance, and high added value.

[0025] The present invention also provides a bio-based segmented polyester polyol. The bio-based segmented polyester polyol provided by the present invention contains difunctional and trifunctional aromatic ring segments, which provide floor coatings with excellent acid and alkali resistance, heat resistance and wear resistance, excellent chemical properties, especially chemical resistance, good mechanical and physical properties, and reliable comprehensive performance; the bio-based segmented polyester polyol provided by the present invention contains castor oil fatty acid side chains, which give the floor coating excellent flexibility, weather resistance, water resistance, moisture resistance and adhesion, so that it can adapt well to changes in ambient temperature, has good UV resistance, greatly extends the service life, and is convenient for construction. The bio-based segmented polyester polyol obtained by the present invention through chemical composition and molecular structure modification has good activity and low molecular weight.

[0026] The present invention also provides a method for preparing the bio-based segmented polyester polyol described in the above-mentioned scheme. This method utilizes castor oil, an aromatic ring-containing polyol, and the phosphorus-containing organothiourea catalyst described in the above-mentioned scheme. Through a selective transesterification reaction, castor oil fatty acid segments are introduced into the molecular structure of the aromatic ring-containing polyol, resulting in a bio-based segmented polyester polyol containing saturated polyether segments and castor oil fatty acid segments as pendant groups. The preparation method provided by the present invention features simple steps, a wide range of raw material sources, improved safety for humans, and environmental friendliness, with broad application prospects.

[0027] The present invention also provides the use of the bio-based segmented polyester polyol described in the above scheme or the bio-based segmented polyester polyol obtained by the preparation method described in the above scheme in a coating. The bio-based segmented polyester polyol provided by the present invention has a low molecular weight, is polyhydroxyl-rich, and is highly branched. It can be used to prepare polyurethane floor coatings. After curing, the floor coating can form a complete interpenetrating network structure of soft and hard segments, endowing the floor paint film with excellent chemical, physical, and mechanical properties, resistance to chemical corrosion, good heat stability, and good adhesion. It is suitable for preparing polyurethane floor coatings with various properties, especially two-component solvent-free polyurethane floor coatings.

[0028] The present invention also provides a polyurethane, wherein the polyester polyol raw material is the bio-based segmented polyester polyol described in the above embodiment or the bio-based segmented polyester polyol obtained by the preparation method described in the above embodiment. The polyurethane provided by the present invention is used in floor coatings, and can form a complete interpenetrating network structure of soft and hard segments in the cured floor coating. The polyurethane is resistant to chemical corrosion and is not swollen, dissolved, destroyed, decomposed, or corroded by chemical media. It remains stable for a long time and has good hardness, impact resistance, weather resistance, wear resistance, and heat stability. It also has good adhesion, low air permeability and water permeability, and can well meet various performance indicators required for floor coatings. DETAILED DESCRIPTION

[0029] The present invention provides a phosphorus-containing organic thiourea catalyst, the structure of which is shown in Formula I:

[0030]

[0031] The phosphorus-containing organic thiourea catalyst provided by the present invention has the characteristics of being metal-free, having high catalytic activity, being flame-retardant, and not requiring removal or separation.

[0032] The present invention also provides a method for preparing the phosphorus-containing organic thiourea catalyst described in the above scheme, comprising the following steps:

[0033] 3,5-bis(trifluoromethyl)phenylisothiocyanate, 2-(diphenylphosphino)ethylamine and a good solvent are mixed and sequentially subjected to a nucleophilic addition reaction, and then a trivalent phosphorus oxidation reaction is carried out under oxygen conditions to obtain the phosphorus-containing organic thiourea catalyst.

[0034] The present invention mixes 3,5-bis(trifluoromethyl)phenylisothiocyanate, 2-(diphenylphosphino)ethylamine, and a good solvent (referred to as the first mixing) to obtain a reaction solution. In the present invention, the molar ratio of the 3,5-bis(trifluoromethyl)phenylisothiocyanate to the 2-(diphenylphosphino)ethylamine can be 1:1 to 1.05, specifically 1:1, 1:1.01, 1:1.02, 1:1.03, 1:1.04, or 1:1.05.

[0035] In the present invention, the good solvent may be a substituted hydrocarbon; the substituted hydrocarbon may be a substituted alkane; the substituted alkane may be a halogenated alkane; the halogenated alkane may be a chlorinated alkane; the chlorinated alkane may be a C1-C8 chlorinated alkane; the C1-C8 chlorinated alkane may be dichloromethane.

[0036] In the present invention, the ratio of the amount of 2-(diphenylphosphino)ethylamine to the volume of the good solvent may be 2 mol:(3-5) L, specifically 2 mol:4 L.

[0037] In the present invention, the first mixing can be performed in a protective atmosphere; the protective atmosphere can be an inert gas; the inert gas can be argon. By performing the mixing in a protective atmosphere, the present invention can avoid the influence of oxygen on the catalyst activity and the esterification reaction, as well as the generation of by-products.

[0038] In the present invention, the first mixing process may include: mixing 2-(diphenylphosphino)ethylamine with a first portion of a good solvent to obtain a 2-(diphenylphosphino)ethylamine solution; mixing 3,5-bis(trifluoromethyl)phenylisothiocyanate with the remaining portion of the good solvent to obtain a premixed solution; and then dropwise adding the 2-(diphenylphosphino)ethylamine solution to the premixed solution under stirring. The present invention, through the above-described mixing order and method, can avoid the generation of by-products and improve the conversion rate of the target product.

[0039] In the present invention, the volume ratio of the first portion of good solvent to the remaining portion of good solvent may be 1:2-3, specifically 1:2.5.

[0040] In the present invention, the stirring rate of the stirring condition may be 200-500 rpm, specifically 300 rpm or 400 rpm.

[0041] In the present invention, the dropping rate may be 10 to 20 mL / min, specifically 15 mL / min.

[0042] After obtaining the reaction liquid, the present invention performs a nucleophilic addition reaction on the reaction liquid to obtain a trivalent phosphorus organic thiourea compound. In the present invention, the nucleophilic addition reaction can be carried out in a protective atmosphere; the protective atmosphere can be an inert gas; the inert gas can be argon; the temperature of the nucleophilic addition reaction can be 20 to 40°C, specifically 25°C or 35°C, and the holding time can be 20 to 48 hours, specifically 24 hours or 36 hours.

[0043] After obtaining a trivalent phosphorus organothiourea compound, the present invention conducts a trivalent phosphorus oxidation reaction on the trivalent phosphorus organothiourea compound under oxygen conditions to obtain the phosphorus-containing organothiourea catalyst. In the present invention, the oxygen conditions can include: introducing oxygen into the reaction solution of the nucleophilic addition reaction; the oxygen introduction rate can be 0.1 to 0.5 L / min, specifically 0.1 L / min, 0.3 L / min, or 0.5 L / min. By slowly introducing oxygen, the present invention can avoid volatilization of the organic solvent and precipitation of the target product.

[0044] In the present invention, the temperature of the trivalent phosphorus oxidation reaction can be 20-30° C., specifically 25° C., and the insulation time can be 2-10 minutes, specifically 5 minutes.

[0045] In the present invention, after the oxidation reaction of trivalent phosphorus, the obtained reaction system may be further desolventized; the desolventizing may be evaporation to dryness; the evaporation to dryness may be vacuum evaporation to dryness; the evaporation to dryness temperature may be 20 to 40° C., specifically 30° C., and the insulation time may be 1 to 2 hours, specifically 1.5 hours; the vacuum degree of the vacuum evaporation to dryness may be -0.095 to -0.100 MPa, specifically -0.097 MPa.

[0046] In the present invention, after the solvent removal, the solid can be mixed with n-hexane (referred to as the second mixing) and then subjected to solid-liquid separation and drying. The present invention can further improve the purity of the phosphorus-containing organic thiourea catalyst by mixing with n-hexane.

[0047] In the present invention, the volume ratio of the solid to n-hexane can be (5-10) g:(20-40) mL, specifically 5 g:20 mL, 5 g:30 mL, 5 g:40 mL, 8 g:20 mL, 8 g:30 mL, 8 g:40 mL, 10 g:20 mL, 10 g:30 mL or 10 g:40 mL.

[0048] In the present invention, the second mixing may be stirring mixing, the stirring mixing speed may be 50 to 100 rpm, specifically 60 rpm, and the mixing time may be 1 to 3 hours, specifically 2 hours.

[0049] In the present invention, the solid-liquid separation can be filtration; the drying can be vacuum drying; the vacuum degree of the vacuum drying can be -0.095 to -0.100 MPa; the temperature of the vacuum drying can be 30 to 50°C, specifically 40°C, and the insulation time can be 6 to 12h, specifically 8h or 10h.

[0050] The present invention also provides the use of the phosphorus-containing organic thiourea catalyst described in the above scheme or the phosphorus-containing organic thiourea catalyst obtained by the preparation method described in the above scheme in an ester exchange reaction.

[0051] The phosphorus-containing organic thiourea catalyst provided by the present invention can be used in ester exchange reactions to prepare polyester polyols or polyurethanes as raw materials for polyurethanes, especially bio-based segmented polyester polyols. The obtained bio-based segmented polyester polyols have high functionality, good activity, low molecular weight, excellent comprehensive performance and high added value.

[0052] The present invention also provides a bio-based segmented polyester polyol, the structure of which is shown in Formula II:

[0053]

[0054] In formula II, Ar is

[0055]

[0056] The average relative molecular mass of the bio-based segmented polyester polyol is 600-800 g / mol.

[0057] In the present invention, the bio-based segmented polyester polyol may have a hydroxyl value of 160 to 400 mg KOH / g, an acid value of ≤2 mg KOH / g, and a viscosity (25° C.) of 1000 to 3500 mPa.s.

[0058] The present invention also provides a method for preparing the bio-based segmented polyester polyol described in the above scheme, comprising the following steps:

[0059] A phosphorus-containing organic thiourea catalyst, an aromatic ring-containing polyol, and dry castor oil are mixed (referred to as the third mixture) to undergo an ester exchange reaction to obtain the bio-based segmented polyester polyol; the phosphorus-containing organic thiourea catalyst is the phosphorus-containing organic thiourea catalyst described in the above scheme or the phosphorus-containing organic thiourea catalyst obtained by the preparation method described in the above scheme.

[0060] In the present invention, the number of aromatic rings of the aromatic ring-containing polyol may be more than one, specifically 1, 2 or 3; the aromatic ring-containing polyol may be a branched aromatic ring-containing polyol; the branched aromatic ring-containing polyol may be a saturated aromatic ring-containing polyether polyol; the saturated aromatic ring-containing polyether polyol may include one or more of polyether polyol, polyoxyethylene ether polyol and polyoxypropylene ether polyol.

[0061] In the present invention, the polyether polyol may be a cashew nut shell liquid polyether polyol; the hydroxyl value of the cashew nut shell liquid polyether polyol may be 320 to 380 mg KOH / g, specifically 340 mg KOH / g or 360 mg KOH / g.

[0062] In the present invention, the polyoxyethylene ether polyol can be bisphenol A polyoxyethylene ether polyol; the hydroxyl value of the bisphenol A polyoxyethylene ether polyol can be 180-350 mg KOH / g, specifically 210 mg KOH / g, 240 mg KOH / g, 270 mg KOH / g, 300 mg KOH / g or 330 mg KOH / g.

[0063] In the present invention, the polyoxypropylene ether polyol may include one or more of bisphenol A polyoxypropylene ether polyol, hydroquinone-based polyoxypropylene ether polyol and 2,5-di-tert-butylhydroquinone-based polyoxypropylene ether polyol.

[0064] In the present invention, the hydroxyl value of the bisphenol A polyoxypropylene ether polyol may be 160 to 335 mg KOH / g, specifically 220 mg KOH / g, 270 mg KOH / g or 320 mg KOH / g.

[0065] In the present invention, the hydroxyl value of the hydroquinone-based polyoxypropylene ether polyol can be 190 to 495 mg KOH / g, specifically 240 mg KOH / g, 280 mg KOH / g, 320 mg KOH / g, 360 mg KOH / g, 400 mg KOH / g, 430 mg KOH / g or 480 mg KOH / g.

[0066] In the present invention, the hydroxyl value of the 2,5-di-tert-butylhydroquinone-based polypropylene ether polyol may be 165 to 330 mg KOH / g, specifically 200 mg KOH / g, 240 mg KOH / g, 280 mg KOH / g or 310 mg KOH / g.

[0067] In the present invention, the mass ratio of the phosphorus-containing organic thiourea catalyst to the aromatic ring-containing polyol can be 6 to 8:7000 to 13000, specifically 6:7000, 7:9000, 8:9000, or 8:13000. The phosphorus-containing organic thiourea catalyst provided by the present invention has high catalytic activity, so only a small amount of addition is required, reducing costs and post-processing difficulty.

[0068] In the present invention, the water content of the dried castor oil may be no more than 2000 ppm, specifically 500 ppm, 1000 ppm or 1500 ppm.

[0069] In the present invention, the method for preparing dried castor oil may include the following steps: heating the castor oil in a protective atmosphere under vacuum conditions. Through this method, the castor oil is dehydrated and impurities are removed simultaneously. Dehydration can prevent the deterioration of catalyst activity and transesterification reactions.

[0070] In the present invention, the acid value of the castor oil may be ≤2.0 mgKOH / g, specifically 1.5 mgKOH / g, and the hydroxyl value may be 154-168 mgKOH / g, specifically 158 mgKOH / g or 166 mgKOH / g.

[0071] In the present invention, the protective atmosphere may be an inert gas or nitrogen; the inert gas may be argon.

[0072] In the present invention, the vacuum degree of the vacuum condition may be -100 to -85 kPa, specifically -90 kPa or -95 kPa.

[0073] In the present invention, the heating may further include heat preservation after heating; the heating rate may be 20° C. / h; and the heat preservation time may be 1 hour.

[0074] In the present invention, the heating temperature may be 80-130° C., specifically 90° C., 100° C., 110° C. or 120° C., and the insulation time may be 1-5 h, specifically 2 h, 3 h or 4 h.

[0075] In the present invention, the mass ratio of the dried castor oil to the aromatic ring-containing polyol can be 45-75:20-40, specifically 50:22, 55:22, 60:22, 65:22, 70:22, 50:26, 55:26, 60:26, 65:26, 70:26, 50:30, 55:30, 60:30, 65:30, 70:30, 50:35, 55:35, 60:35, 65:35, 70:35, 50:38, 55:38, 60:38, 65:38 or 70:38.

[0076] In the present invention, the third mixing equipment can be a dry stainless steel reactor.

[0077] In the present invention, the third mixing may be: premixing dry castor oil and a phosphorus-containing organic thiourea catalyst to obtain a premix, and then mixing the premix with the aromatic ring-containing polyol.

[0078] In the present invention, the temperature may be raised to the temperature of the transesterification reaction before the transesterification reaction; the rate of the temperature increase may be 15 to 25° C. / h, specifically 20° C. / h.

[0079] In the present invention, the transesterification reaction can be carried out in a protective atmosphere; the protective atmosphere can be an inert gas or nitrogen; the inert gas can be argon; the transesterification reaction can include sequentially performing a normal pressure transesterification stage and a vacuum transesterification stage.

[0080] In the present invention, the temperature of the atmospheric pressure transesterification stage can be 80-180°C, specifically 85°C, 90°C, 95°C, 100°C, 105°C, 110°C, 115°C, 120°C, 125°C, 130°C, 135°C, 140°C, 145°C, 150°C, 155°C, 160°C, 165°C, 170°C or 175°C, and the holding time can be 5-10 hours, specifically 6 hours, 7 hours, 8 hours or 9 hours. By using the phosphorus-containing organic thiourea catalyst provided by the present invention, the present invention achieves the preparation of bio-based segmented polyester polyols at a low reaction temperature.

[0081] In the present invention, the temperature of the vacuum transesterification stage can be 80-180°C, specifically 85°C, 90°C, 95°C, 100°C, 105°C, 110°C, 115°C, 120°C, 125°C, 130°C, 135°C, 140°C, 145°C, 150°C, 155°C, 160°C, 165°C, 170°C or 175°C, the vacuum degree can be -100-80kPa, specifically -95kPa, -90kPa or -85kPa, and the insulation time can be 2-5h, specifically 3h or 4h.

[0082] In the present invention, the reaction system may be cooled after the transesterification reaction; the cooling rate may be 20-40°C / h, specifically 30°C / h, and the final temperature may be 40-60°C, specifically 50°C.

[0083] The present invention also provides the use of the bio-based segmented polyester polyol described in the above scheme or the bio-based segmented polyester polyol obtained by the preparation method described in the above scheme in coatings.

[0084] The bio-based segmented polyester polyol provided by the present invention has high functionality and low molecular weight, and can be used to prepare polyurethane floor coatings. It can enable the cured floor coating to form a complete soft and hard segment interpenetrating network structure, endowing the floor paint film with good chemical properties, physical properties and mechanical properties, resistance to chemical corrosion, good heat stability, and good adhesion. It is suitable for preparing polyurethane floor coatings with various properties, especially two-component solvent-free polyurethane floor coatings.

[0085] The present invention also provides a polyurethane, wherein the polyester polyol raw material is the bio-based segmented polyester polyol described in the above scheme or the bio-based segmented polyester polyol obtained by the preparation method described in the above scheme.

[0086] The polyurethane provided by the present invention is used for floor coatings, which can enable the cured floor coatings to form a complete soft and hard segment interpenetrating network structure, is resistant to chemical corrosion, and is not swollen, dissolved, destroyed, decomposed or corroded by chemical media. It remains stable for a long time, has good hardness, impact resistance, weather resistance, wear resistance and heat stability, and has good adhesion, low air permeability and water permeability, and can well meet various performance index requirements of floor coatings.

[0087] In order to further illustrate the present invention, the scheme of the present invention is described in detail below with reference to the embodiments, but they should not be understood as limiting the scope of protection of the present invention.

[0088] Example 1

[0089] Under argon protection, 3,5-bis(trifluoromethyl)phenylisothiocyanate (27.1 g, 100 mmol) and dichloromethane (100 mL) were mixed uniformly, and a dichloromethane solution (2 mmol / mL) of 2-(diphenylphosphino)ethylamine (22.9 g, 100 mmol) was added dropwise (dropping rate of 15 mL / min) under vigorous stirring (stirring rate of 300 rpm). The mixture was reacted at 25 ° C for 24 h, and then oxygen was slowly introduced into the reaction solution at 0.3 L / min. The reaction was continued for 5 min, and the dichloromethane was evaporated under vacuum at 30 ° C (vacuum degree of -0.1 MPa), and then n-hexane (200 mL) was added and vigorously stirred (stirring rate of 60 rpm) for 2 h, filtered, and dried at 40 ° C under a vacuum degree of -0.1 MPa for 8 h to obtain 49 g of phosphorus-containing organic thiourea catalyst as a white solid.

[0090] 25 kg of castor oil (acid value 1.8 mgKOH / g, hydroxyl value 161.0 mgKOH / g) was added to a dry stainless steel reactor filled with nitrogen, and the reactor was heated to 120° C. at a rate of 20° C. / h and kept warm for 1 h. Impurities were removed and dehydrated at 120° C. and a vacuum degree of -95 kPa for 3 h.

[0091] 8.0 g of a phosphorus-containing organic thiourea catalyst and 13 kg of a cashew nut shell liquid polyether polyol having a hydroxyl value of 340 mg KOH / g were added to the reactor, the reactor was heated to 130 ° C. at a rate of 20 ° C. / h and kept warm for 6 h, and then the reactor was evacuated for ester exchange reaction. The reaction was continued under a vacuum degree of -90 kPa for 3 h, and the temperature was lowered to 50 ° C. at a rate of 30 ° C. / h to obtain a bio-based block polyester polyol.

[0092] The bio-based segmented polyester polyol prepared in this example has a hydroxyl value of 224 mg KOH / g, an acid value of 0.6 mg KOH / g, a viscosity (25° C.) of 1480 mPa·s, and an average relative molecular mass of 723 g / mol.

[0093] Example 2

[0094] 25 kg of castor oil (acid value 1.8 mgKOH / g, hydroxyl value 161.0 mgKOH / g) was added to a dry stainless steel reactor filled with nitrogen, and the reactor was heated to 120° C. at a rate of 20° C. / h and kept at this temperature for 1 h. Impurities were removed and dehydrated for 3 h under a vacuum degree of -95 kPa.

[0095] 7.0 g of a phosphorus-containing organic thiourea catalyst (Example 1) and 9.0 kg of bisphenol A polyoxypropylene ether polyol having a hydroxyl value of 322 mgKOH / g were added to the reactor, and the reactor was heated to 130° C. at a rate of 20° C. / h and kept warm for 6 h. The reactor was then evacuated for ester exchange reaction, and the reaction was continued at a vacuum degree of -90 kPa for 3 h. The reaction was then cooled to 60° C. at a rate of 20° C. / h to obtain a bio-based block polyester polyol.

[0096] The bio-based segmented polyester polyol prepared in this example has a hydroxyl value of 206 mg KOH / g, an acid value of 0.7 mg KOH / g, a viscosity (25° C.) of 1720 mPa·s, and an average relative molecular mass of 652 g / mol.

[0097] Example 3

[0098] 25 kg of castor oil (acid value 1.8 mgKOH / g, hydroxyl value 161.0 mgKOH / g) was added to a dry stainless steel reactor filled with nitrogen, and the reactor was heated to 120° C. at a rate of 20° C. / h and kept at this temperature for 1 h. Impurities were removed and dehydrated for 3 h under a vacuum degree of -95 kPa.

[0099] 6.2 g of phosphorus-containing organic thiourea catalyst (Example 1), 7.0 kg of cashew nut shell liquid polyether polyol having a hydroxyl value of 340 mg KOH / g, and 4.5 kg of bisphenol A polyoxypropylene ether polyol having a hydroxyl value of 322 mg KOH / g were added to the reactor, and the reactor was heated to 130 ° C. at a rate of 20 ° C. / h and kept warm for 6 h. The reactor was then evacuated for ester exchange reaction, and the reaction was continued under a vacuum degree of -90 kPa for 3 h. The temperature was lowered to 40 ° C. at a rate of 40 ° C. / h to obtain a bio-based block polyester polyol.

[0100] The bio-based segmented polyester polyol prepared in this example has a hydroxyl value of 217 mg KOH / g, an acid value of 0.5 mg KOH / g, a viscosity (25° C.) of 1590 mPa·s, and an average relative molecular mass of 689 g / mol.

[0101] Example 4

[0102] 25 kg of castor oil (acid value 1.8 mgKOH / g, hydroxyl value 161.0 mgKOH / g) was added to a dry stainless steel reactor filled with nitrogen, and the reactor was heated to 120° C. at a rate of 20° C. / h and kept at this temperature for 1 h. Impurities were removed and dehydrated for 3 h under a vacuum degree of -95 kPa.

[0103] 8.0 g of a phosphorus-containing organic thiourea catalyst (Example 1) and 9.0 kg of 2,5-di-tert-butylhydroquinone-based polypropylene ether polyol having a hydroxyl value of 325 mgKOH / g were added to the reactor, and the reactor was heated to 130° C. at a rate of 20° C. / h and kept warm for 6 h. The reactor was then evacuated for an ester exchange reaction, and the reaction was continued at a vacuum degree of -90 kPa for 3 h. The reaction was then cooled to 50° C. at a rate of 30° C. / h to obtain a bio-based block polyester polyol.

[0104] The bio-based segmented polyester polyol prepared in this example has a hydroxyl value of 208 mg KOH / g, an acid value of 0.6 mg KOH / g, a viscosity (25° C.) of 1950 mPa·s, and an average relative molecular mass of 644 g / mol.

[0105] Comparative Example 1 (using traditional catalyst)

[0106] 25 kg of castor oil (acid value 1.8 mgKOH / g, hydroxyl value 161.0 mgKOH / g) was added to a dry stainless steel reactor filled with nitrogen, and the reactor was heated to 120° C. at a rate of 20° C. / h and kept at this temperature for 1 h. Impurities were removed and dehydrated for 3 h under a vacuum degree of -95 kPa.

[0107] 8.0 g of dibutyltin dilaurate and 13 kg of cashew nut shell liquid polyether polyol with a hydroxyl value of 340 mg KOH / g were added to the reactor, and the reactor was heated to 130° C. at a rate of 20° C. / h and kept warm for 6 h. The reactor was then evacuated for ester exchange reaction, and the reaction was continued under a vacuum degree of -90 kPa for 3 h. The temperature was then lowered to 50° C. at a rate of 30° C. / h to obtain a bio-based block polyester polyol.

[0108] The bio-based segmented polyester polyol prepared in this comparative example has a hydroxyl value of 221 mg KOH / g, an acid value of 0.5 mg KOH / g, a viscosity (25° C.) of 1535 mPa.s, and an average relative molecular mass of 733 g / mol.

[0109] Comparative Example 2 (using traditional catalyst)

[0110] 25 kg of castor oil (acid value 1.8 mgKOH / g, hydroxyl value 161.0 mgKOH / g) was added to a dry stainless steel reactor filled with nitrogen, and the reactor was heated to 120° C. at a rate of 20° C. / h and kept at this temperature for 1 h. Impurities were removed and dehydrated for 3 h under a vacuum degree of -95 kPa.

[0111] 8.0 g of tetrabutyl titanate and 13 kg of cashew nut shell liquid polyether polyol with a hydroxyl value of 340 mg KOH / g were added to the reactor, the reactor was heated to 130 ° C at a rate of 20 ° C / h and kept warm for 6 hours, and then the reactor was vacuumed for ester exchange reaction. The reaction was continued under a vacuum degree of -90 kPa for 3 hours, and the temperature was lowered to 50 ° C at a rate of 30 ° C / h to obtain a bio-based block polyester polyol.

[0112] The bio-based segmented polyester polyol prepared in this comparative example has a hydroxyl value of 215 mg KOH / g, an acid value of 0.4 mg KOH / g, a viscosity (25° C.) of 1360 mPa·s, and an average relative molecular mass of 678 g / mol.

[0113] Test Example 1

[0114] The performance test of the bio-based block polyester polyols prepared in Examples 1 to 4 and Comparative Examples 1 to 2 was carried out. The test method was as follows: the bio-based block polyester polyols prepared in Examples 1 to 4 and Comparative Examples 1 to 2 were respectively mixed with the HT-300 curing agent according to an R value of 1.05 to prepare a two-component solvent-free floor coating, and then the two-component solvent-free floor coating was evenly applied to the floor surface with a thickness of 0.5 mm. The performance of the floor surface coating was tested in accordance with the requirements of the national standard GB / T22374-2018. The test results are shown in Table 1.

[0115] Table 1 Performance test results of Examples 1 to 4 and Comparative Examples 1 to 2

[0116]

[0117] As shown in Table 1, the bio-based block polyester polyols prepared in Examples 1 to 4 are subjected to a series of impurity removal, dehydration and transesterification reactions to introduce specific aromatic rings into the molecular structure of natural oil castor oil, thereby producing block polyester polyols with excellent mechanical properties, good temperature resistance and water resistance, which greatly improve the chemical corrosion resistance and wear resistance of the two-component solvent-free floor coating.

[0118] It can be seen from the above embodiments that the bio-based segmented polyester polyol provided by the present invention can be used to prepare polyurethane floor coatings, which can enable the floor coatings to form a complete interpenetrating network structure of soft and hard segments, endow the floor paint film with good chemical properties, physical properties and mechanical properties, and is resistant to chemical corrosion, and is not swollen, dissolved, destroyed, decomposed and corroded by chemical media. It remains in a stable state for a long time, and can well meet the various performance index requirements of floor coatings, and meet the special requirements of industrial floors, commercial floors and public facilities.

[0119] Although the above embodiment provides a detailed description of the present invention, it is only a part of the embodiments of the present invention, not all of the embodiments. Other embodiments can be obtained based on this embodiment without creativity, and these embodiments all fall within the scope of protection of the present invention.

Claims

1. A phosphorus-containing organic thiourea catalyst, characterized in that The structure is shown in Formula I:

2. The method for preparing the phosphorus-containing organic thiourea catalyst according to claim 1, characterized in that: The following steps are involved: 3,5-bis(trifluoromethyl)phenylisothiocyanate, 2-(diphenylphosphino)ethylamine and a good solvent are mixed and sequentially subjected to a nucleophilic addition reaction, and then a trivalent phosphorus oxidation reaction is carried out under oxygen conditions to obtain the phosphorus-containing organic thiourea catalyst.

3. The preparation method according to claim 2, characterized in that The molar ratio of the 3,5-bis(trifluoromethyl)phenylisothiocyanate to 2-(diphenylphosphino)ethylamine is 1:1 to 1.

05.

4. Use of the phosphorus-containing organic thiourea catalyst according to claim 1 or the phosphorus-containing organic thiourea catalyst obtained by the preparation method according to any one of claims 2 to 3 in an ester exchange reaction.

5. A bio-based segmented polyester polyol, characterized in that: The structure is shown in Formula II: In formula II, Ar is The average relative molecular mass of the bio-based segmented polyester polyol is 600-800 g / mol.

6. The bio-based segmented polyester polyol according to claim 5, characterized in that The bio-based segmented polyester polyol has a hydroxyl value of 160 to 400 mg KOH / g, an acid value of ≤2 mg KOH / g, and a viscosity at 25° C. of 1000 to 3500 mPa.s.

7. The method for preparing the bio-based segmented polyester polyol according to any one of claims 5 to 6, characterized in that: The following steps are involved: A phosphorus-containing organic thiourea catalyst, an aromatic ring-containing polyol, and dry castor oil are mixed to carry out an ester exchange reaction to obtain the bio-based segmented polyester polyol; The phosphorus-containing organic thiourea catalyst is the phosphorus-containing organic thiourea catalyst according to claim 1 or the phosphorus-containing organic thiourea catalyst obtained by the preparation method according to any one of claims 2 to 3.

8. The preparation method according to claim 7, characterized in that The transesterification reaction is carried out in a protective atmosphere; The transesterification reaction comprises sequentially performing a normal pressure transesterification stage and a vacuum transesterification stage; The temperature of the atmospheric pressure transesterification stage is 80-180°C, and the holding time is 5-10 hours; The temperature of the vacuum transesterification stage is 80 to 180° C., the vacuum degree is -100 to -80 kPa, and the insulation time is 2 to 5 hours.

9. Use of the bio-based block polyester polyol according to any one of claims 5 to 6 or the bio-based block polyester polyol obtained by the preparation method according to any one of claims 7 to 8 in coatings.

10. A polyurethane, characterized in that The polyester polyol raw material is the bio-based block polyester polyol described in any one of claims 5 to 6 or the bio-based block polyester polyol obtained by the preparation method described in any one of claims 7 to 8.

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