Polyurethane waterproof agent containing long-chain alkane and preparation method thereof

Abstract

The invention discloses a polyurethane waterproofing agent containing long-chain alkane and a preparation method thereof, and when the polyurethane waterproofing agent is prepared, polydimethylsiloxane with high silicon-oxygen bond energy, low surface energy and molecular chain elasticity and glyceryl monostearate containing long-chain hydrophobic alkane groups are introduced into a polyurethane system; comprising the following steps: polymerizing TDI (toluene diisocynate), TMP (trimethylolpropane) and polydimethylsiloxane to obtain a prepolymer 1; the prepolymer 1 is subjected to a polymerization reaction with N-MDEA, diacetylmonoxime and GMS in the presence of a catalyst DBTDL, and a prepolymer 2 is obtained; acidifying the prepolymer 2 into salt to obtain a prepolymer 3; uniformly mixing the prepolymer 3 and deionized water, and carrying out self-emulsification through an emulsifying machine or by applying an instantaneous nano precipitation technology FNP to obtain a polyurethane emulsion containing long-chain alkane, so as to prepare the polyurethane waterproof agent containing long-chain alkane. The polyurethane waterproof agent prepared by using the FNP has smaller particle size, better stability and good waterproofness, can be continuously emulsified, and has a relatively great application prospect in the field of fabrics.

Description

Technical Field

[0001] The invention relates to the technical field of waterproofing agents, and in particular to a polyurethane waterproofing agent containing long-chain alkane and a preparation method thereof. Background Art

[0002] Polyurethane waterproofing agents are mainly formed by the reaction of isocyanates and polyols to form high molecular polymers with excellent waterproof properties. With the development of science and technology, people are pursuing higher and higher functionalization of fabrics. Functional fabrics have many important emerging applications, such as waterproofing. Fabric functionalization is to modify the surface of fabrics with reagents with unique structures, which can change the surface structure of the original fabric and provide new functions. Usually, some low surface energy compounds, such as fluorinated compounds, silicone complexes and long-chain alkane substances, can be introduced to increase the water repellency of waterborne polyurethane.

[0003] Fluorinated compounds are widely used in polyurethane modification, which has the following advantages: excellent waterproof effect, can form a low surface energy film on the fabric surface, effectively block water penetration, excellent oil resistance, can prevent oily stains from invading fibers, good durability, waterproof effect can be sustained for multiple washings, has little effect on the feel of the fabric, will not significantly change the softness and breathability of the fabric, has a wide range of applications, and can be used for various types of fiber fabrics; however, most of them will release biotoxic substances, which are potentially harmful to humans and ecosystems. Some fluorinated compounds have been proven to be bioaccumulative and toxic, causing serious damage to the ecosystem. Therefore, the development of fluorine-free waterproofing agents has become an important trend; fluorine-free waterproofing agents are environmentally friendly, biodegradable, will not exist in the environment for a long time, are safer for humans and ecosystems, have a cleaner production process, reduce hazardous waste emissions, meet the increasingly stringent environmental protection regulations of various countries, and have relatively low costs, which is conducive to reducing production costs.

[0004] With the progress of society and the improvement of people's living standards, environmental protection and health have attracted more extensive attention. In the context of rapid development, new requirements have been put forward for the waterproof performance, safety and environmental protection of polyurethane waterproofing agents. Therefore, the present invention provides a polyurethane waterproofing agent containing long-chain alkanes and a preparation method thereof. Summary of the invention

[0005] The object of the present invention is to provide a polyurethane waterproofing agent containing long-chain alkanes and a preparation method thereof, wherein the preparation method can obtain a polyurethane waterproofing agent with excellent properties to solve environmental problems and insufficient waterproofing effects.

[0006] In order to achieve the above-mentioned object of the invention, the technical solution adopted by the present invention is: a method for preparing a polyurethane waterproofing agent containing a long-chain alkane, comprising the following steps:

[0007] (1) in a nitrogen atmosphere, toluene diisocyanate (TDI), polydimethylsiloxane and n-propane (TMP) are added to a container equipped with a mechanical stirrer, a thermometer and a reflux condenser with a drying tube, and vacuum dried at high temperature until the raw materials contain no moisture, and the polymerization reaction temperature is controlled in an anhydrous environment and the mixture is stirred for 3 to 4 hours to obtain an NCO-terminated prepolymer 1;

[0008] (2) In a nitrogen atmosphere, dry glyceryl monostearate (GMS) and a catalyst dibutyltin dilaurate (DBTDL) are added to the prepolymer 1 obtained in step (1) under controlled temperature, diluted with acetone, and the temperature is lowered. An acetone solution of N-methyldiethanolamine (N-MDEA) as a cationic chain extender is slowly added dropwise to the container under controlled stirring speed to react, and some acetone is added to the system to adjust the viscosity of the mixture during the reaction, and butanone oxime is added thereto. The reaction is continued for 0.5 to 1 hour to obtain a prepolymer 2;

[0009] (3) Controlling the temperature, adding glacial acetic acid to the prepolymer 2 obtained in step (2), acidifying to obtain prepolymer 3, adding deionized water, and preparing a polyurethane emulsion by an emulsifier or FNP self-emulsification, and decompressing the polyurethane emulsion to remove organic solvents such as acetone, thereby obtaining the polyurethane waterproofing agent containing long-chain alkanes.

[0010] Preferably, in step (1), the polydimethylsiloxane is selected from one of hydroxymethyl polydimethylsiloxane, hydroxyethyl polydimethylsiloxane and hydroxypropyl polydimethylsiloxane.

[0011] Preferably, in step (1), the concentration of n-propane (TMP) is 1 wt% to 2 wt%, the polymerization reaction temperature is 75 to 90°C, the stirring speed is 150 to 220 r / min, and the molar ratio of -NCO / -OH of the reactants in the polymerization reaction is 1.2 to 1.6.

[0012] Further preferably, in step (1), the concentration of normal propane (TMP) is 2 wt %, the polymerization reaction temperature is 80° C., and the molar ratio of -NCO / -OH of the reactants in the polymerization reaction is 1.4.

[0013] Preferably, in step (1), the temperature of vacuum drying at high temperature until the raw material contains no moisture is controlled to be 105-115°C.

[0014] Preferably, in step (2), the concentration of GMS is 10 wt% to 20 wt%, the concentration of catalyst DBTDL is 0.01 wt% to 0.02 wt%, the controlled temperature is 40 to 50°C, and the lowered temperature is 20 to 30°C.

[0015] Preferably, in step (2), N-methyldiethanolamine (N-MDEA) and acetone are diluted in a mass ratio of 1 to 5 and slowly added dropwise, and the stirring speed is controlled to be 150 to 220 r / min.

[0016] Preferably, in step (2), butanone oxime is added in an amount equal to the molar number of the remaining NCO groups, and at the same time, glacial acetic acid is added in an amount equal to the molar number of the N-methyldiethanolamine in step 2.

[0017] Preferably, in step (3), the controlled temperature is 20-25°C, the mass ratio of the prepolymer 3 to deionized water is 1-3:1-4, the rotation speed of the emulsifier is 4800-5000 r / min, and the emulsification time is 8-10 min; further preferably, the rotation speed of the emulsifier is 5000 r / min, and the emulsification time is 10 min.

[0018] Preferably, in step (3), the FNP self-emulsification is prepared by using instantaneous nanoprecipitation technology FNP, using a microreactor, taking prepolymer 3 as stream No. 1 and deionized water as stream No. 2, flushing prepolymer 3 into the tiny cavity of the microreactor for rapid and uniform mixing to prepare a polyurethane emulsion.

[0019] The present application also claims protection for a polyurethane waterproofing agent containing long-chain alkanes prepared by the above-mentioned method for preparing the polyurethane waterproofing agent containing long-chain alkanes.

[0020] Due to the application of the above technical solution, the present invention has the following advantages compared with the prior art:

[0021] 1. The polydimethylsiloxane in the present invention has high silicon-oxygen bond energy, low surface energy and molecular chain flexibility, and can provide good heat resistance, weather resistance, and waterproof properties;

[0022] 2. In the present invention, trimethylolpropane is a triol, which is introduced into waterborne polyurethane to provide a branched structure; glyceryl monostearate contains a long-chain hydrophobic alkane group, which is introduced into the waterproofing agent to increase the content of long-chain alkanes in the molecule and the hydrophobicity of the fabric; it is environmentally friendly, biodegradable, and will not exist in the environment for a long time; it is safer for the human body and the ecosystem; the production process is cleaner and reduces the emission of hazardous waste; it meets the increasingly stringent environmental protection regulations of various countries, and the waterproofing effect can reach level 4-5. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, some of the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0024] Figure 1 This is a physical picture of the device for testing the waterproof level of Example 1 of the present invention;

[0025] Figure 2 Schematic diagram of using FNP in Examples 4-6 of the present invention;

[0026] Figure 3 The physical pictures of the samples of Examples 1-3, 4-6 and Comparative Example 1 of the present invention;

[0027] Figure 4 The waterproof level of Examples 1-3, 4-6 and Comparative Example 1 of the present invention is shown in the figure;

[0028] Figure 5 Schematic diagram of contact angles of Examples 1-3, 4-6 and Comparative Example 1 on fabrics;

[0029] Figure 6 The graph of the particle size variation with GMS of Examples 1-3 and Comparative Example 1 of the present invention;

[0030] Figure 7 This is a comparison curve of the particle size changes with GMS of Examples 1-3 and 4-6 of the present invention;

[0031] Figure 8 This is a comparison curve of PDI versus GMS for Examples 1-3 and 4-6 of the present invention;

[0032] Among them, Figure 3 -Attached Figure 5 The sequence numbers (1)(2)(3)(4)(5)(6) correspond to Examples 1-6 respectively, and the sequence number (7) corresponds to Example 1. DETAILED DESCRIPTION

[0033] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0034] Example 1

[0035] See attached Figure 1 And attached Figure 3-8 This embodiment provides a method for preparing a polyurethane waterproofing agent containing a long-chain alkane, comprising the following steps:

[0036] (1) In a nitrogen atmosphere, 3 g of TDI, 5.235 g of hydroxypropyl polydimethylsiloxane and 0.165 g of TMP were added to a three-necked round-bottom flask equipped with a mechanical stirrer, a thermometer and a reflux condenser with a drying tube, and vacuum dried at 110° C. until the raw materials contained no moisture, and the mixture was stirred at 80° C. in an anhydrous environment for 3 hours to obtain an NCO-terminated prepolymer 1;

[0037] (2) In a nitrogen atmosphere, 1 g of dry GMS and a few drops of catalyst DBTDL were added to the prepolymer 1 obtained in step (1) at 45° C., diluted with a small amount of acetone, and an acetone solution of N-MDEA as a cationic chain extender was slowly added to the flask at 25° C., and some acetone was added to the system to adjust the viscosity of the mixture during the reaction, and then 0.861 g of butanone oxime was added thereto, and the reaction was continued for 0.5 hour to obtain prepolymer 2;

[0038] (3) adding 0.302 g of glacial acetic acid to the prepolymer 2 obtained in step (2) at 25° C., acidifying to obtain a prepolymer 3, adding deionized water, wherein the mass ratio of the prepolymer 3 to the deionized water is 1:3, and self-emulsifying with an emulsifier to obtain a polyurethane emulsion, wherein the rotation speed of the emulsifier is 5000 r / min, and the emulsification time is 10 min. The obtained polyurethane emulsion is decompressed to remove organic solvents such as acetone, thereby obtaining the polyurethane waterproofing agent containing long-chain alkanes.

[0039] Example 2

[0040] See attached Figure 3-8 This embodiment provides a method for preparing a polyurethane waterproofing agent containing a long-chain alkane, comprising the following steps:

[0041] (1) In a nitrogen atmosphere, 3.242 g of TDI, 4.5 g of hydroxypropyl polydimethylsiloxane and 0.158 g of TMP were added to a three-necked round-bottom flask equipped with a mechanical stirrer, a thermometer and a reflux condenser with a drying tube, and vacuum dried at 110° C. until the raw materials contained no moisture, and the mixture was stirred at 80° C. in an anhydrous environment for 3 hours to obtain an NCO-terminated prepolymer 1;

[0042] (2) In a nitrogen atmosphere, 1.5 g of dry GMS and a few drops of catalyst DBTDL were added to the prepolymer 1 obtained in step (1) at 45° C., diluted with a small amount of acetone, and an acetone solution of N-MDEA as a cationic chain extender was slowly added to the flask at 25° C., and some acetone was added to the system to adjust the viscosity of the mixture during the reaction, and then 0.937 g of butanone oxime was added thereto, and the reaction was continued for 0.5 hour to obtain prepolymer 2;

[0043] (3) adding 0.302 g of glacial acetic acid to the prepolymer 2 obtained in step (2) at 25° C., acidifying to obtain a prepolymer 3, adding deionized water, wherein the mass ratio of the prepolymer 3 to the deionized water is 1:3, and self-emulsifying with an emulsifier to obtain a polyurethane emulsion, wherein the rotation speed of the emulsifier is 5000 r / min, and the emulsification time is 10 min. The obtained polyurethane emulsion is decompressed to remove organic solvents such as acetone, thereby obtaining the polyurethane waterproofing agent containing long-chain alkanes.

[0044] Example 3

[0045] See attached Figure 3-8 This embodiment provides a method for preparing a polyurethane waterproofing agent containing a long-chain alkane, comprising the following steps:

[0046] (1) In a nitrogen atmosphere, 3.452 g of TDI, 3.8 g of hydroxypropyl polydimethylsiloxane and 0.148 g of TMP were added to a three-necked round-bottom flask equipped with a mechanical stirrer, a thermometer and a reflux condenser with a drying tube, and vacuum dried at 110° C. until the raw materials contained no moisture, and the mixture was stirred at 80° C. in an anhydrous environment for 3 hours to obtain an NCO-terminated prepolymer 1;

[0047] (2) In a nitrogen atmosphere, 2 g of dry GMS and a few drops of catalyst DBTDL were added to the prepolymer 1 obtained in step (1) at 45° C., diluted with a small amount of acetone, and an acetone solution of N-MDEA as a cationic chain extender was slowly added to the flask at 25° C., and some acetone was added to the system to adjust the viscosity of the mixture during the reaction, and then 0.985 g of butanone oxime was added thereto, and the reaction was continued for 0.5 hour to obtain prepolymer 2;

[0048] (3) adding 0.302 g of glacial acetic acid to the prepolymer 2 obtained in step (2) at 25° C., acidifying to obtain a prepolymer 3, adding deionized water, wherein the mass ratio of the prepolymer 3 to the deionized water is 1:3, and self-emulsifying with an emulsifier to obtain a polyurethane emulsion, wherein the rotation speed of the emulsifier is 5000 r / min, and the emulsification time is 10 min. The obtained polyurethane emulsion is decompressed to remove organic solvents such as acetone, thereby obtaining the polyurethane waterproofing agent containing long-chain alkanes.

[0049] Example 4

[0050] See attached Figure 2-5 And attached Figure 7-8 This embodiment provides a method for preparing a polyurethane waterproofing agent containing a long-chain alkane, comprising the following steps:

[0051] (1) In a nitrogen atmosphere, 3 g of TDI, 5.235 g of hydroxypropyl polydimethylsiloxane and 0.165 g of TMP were added to a three-necked round-bottom flask equipped with a mechanical stirrer, a thermometer and a reflux condenser with a drying tube, and vacuum dried at 110° C. until the raw materials contained no moisture, and the mixture was stirred at 80° C. in an anhydrous environment for 3 hours to obtain an NCO-terminated prepolymer 1;

[0052] (2) In a nitrogen atmosphere, 1 g of dry GMS and a few drops of catalyst DBTDL were added to the prepolymer 1 obtained in step (1) at 45° C., diluted with a small amount of acetone, and an acetone solution of N-MDEA as a cationic chain extender was slowly added to the flask at 25° C., and some acetone was added to the system to adjust the viscosity of the mixture during the reaction, and then 0.861 g of butanone oxime was added thereto, and the reaction was continued for 0.5 hour to obtain prepolymer 2;

[0053] (3) adding 0.302 g of glacial acetic acid to the prepolymer 2 obtained in step (2) at 25° C. to obtain prepolymer 3 after acidification, using FNP, with prepolymer 3 as stream No. 1 and deionized water as stream No. 2, flushing prepolymer 3 into a tiny cavity of a reactor and mixing them quickly and evenly to obtain a polyurethane emulsion, decompressing the polyurethane emulsion to remove organic solvents such as acetone and the like, to obtain the polyurethane waterproofing agent containing long-chain alkanes.

[0054] Example 5

[0055] See attached Figure 2-5 And attached Figure 7-8 This embodiment provides a method for preparing a polyurethane waterproofing agent containing a long-chain alkane, comprising the following steps:

[0056] (1) In a nitrogen atmosphere, 3.242 g of TDI, 4.5 g of hydroxypropyl polydimethylsiloxane and 0.158 g of TMP were added to a three-necked round-bottom flask equipped with a mechanical stirrer, a thermometer and a reflux condenser with a drying tube, and vacuum dried at 110° C. until the raw materials contained no moisture, and the mixture was stirred at 80° C. in an anhydrous environment for 3 hours to obtain an NCO-terminated prepolymer 1;

[0057] (2) In a nitrogen atmosphere, 1.5 g of dry GMS and a few drops of catalyst DBTDL were added to the prepolymer 1 obtained in step (1) at 45° C., diluted with a small amount of acetone, and an acetone solution of N-MDEA as a cationic chain extender was slowly added to the flask at 25° C., and some acetone was added to the system to adjust the viscosity of the mixture during the reaction, and then 0.937 g of butanone oxime was added thereto, and the reaction was continued for 0.5 hour to obtain prepolymer 2;

[0058] (3) adding 0.302 g of glacial acetic acid to the prepolymer 2 obtained in step (2) at 25° C. to obtain prepolymer 3 after acidification, using FNP, with prepolymer 3 as stream No. 1 and deionized water as stream No. 2, flushing prepolymer 3 into a tiny cavity of a reactor and mixing them quickly and evenly to obtain a polyurethane emulsion, decompressing the polyurethane emulsion to remove organic solvents such as acetone and the like, to obtain the polyurethane waterproofing agent containing long-chain alkanes.

[0059] Example 6

[0060] See attached Figure 2-5 And attached Figure 7-8 This embodiment provides a method for preparing a polyurethane waterproofing agent containing a long-chain alkane, comprising the following steps:

[0061] (1) In a nitrogen atmosphere, 3.452 g of TDI, 3.8 g of hydroxypropyl polydimethylsiloxane and 0.148 g of TMP were added to a three-necked round-bottom flask equipped with a mechanical stirrer, a thermometer and a reflux condenser with a drying tube, and vacuum dried at 110° C. until the raw materials contained no moisture, and the mixture was stirred at 80° C. in an anhydrous environment for 3 hours to obtain an NCO-terminated prepolymer 1;

[0062] (2) In a nitrogen atmosphere, 2 g of dry GMS and a few drops of catalyst DBTDL were added to the prepolymer 1 obtained in step (1) at 45° C., diluted with a small amount of acetone, and an acetone solution of N-MDEA as a cationic chain extender was slowly added to the flask at 25° C., and some acetone was added to the system to adjust the viscosity of the mixture during the reaction, and then 0.985 g of butanone oxime was added thereto, and the reaction was continued for 0.5 hour to obtain prepolymer 2;

[0063] (3) adding 0.302 g of glacial acetic acid to the prepolymer 2 obtained in step (2) at 25° C. to obtain prepolymer 3 after acidification, using FNP, with prepolymer 3 as stream No. 1 and deionized water as stream No. 2, flushing prepolymer 3 into a tiny cavity of a reactor and mixing them quickly and evenly to obtain a polyurethane emulsion, decompressing the polyurethane emulsion to remove organic solvents such as acetone and the like, to obtain the polyurethane waterproofing agent containing long-chain alkanes.

[0064] Comparative Example 1

[0065] This embodiment provides a method for preparing a polyurethane waterproofing agent containing a long-chain alkane, comprising the following steps:

[0066] (1) In a nitrogen atmosphere, 3.452 g of TDI, 3.8 g of hydroxypropyl polydimethylsiloxane and 0.148 g of TMP were added to a three-necked round-bottom flask equipped with a mechanical stirrer, a thermometer and a reflux condenser with a drying tube, and vacuum dried at 110° C. until the raw materials contained no moisture, and the mixture was stirred at 80° C. in an anhydrous environment for 3 hours to obtain an NCO-terminated prepolymer 1;

[0067] (2) In a nitrogen atmosphere, a few drops of catalyst DBTDL were added to the prepolymer 1 obtained in step (1) at 25° C., diluted with a small amount of acetone, an acetone solution of N-MDEA as a cationic chain extender was slowly added to the flask, and some acetone was added to the system to adjust the viscosity of the mixture during the reaction, to obtain prepolymer 2;

[0068] (3) adding 0.302 g of glacial acetic acid to the prepolymer 2 obtained in step (2) at 25° C., acidifying to obtain a prepolymer 3, adding deionized water, wherein the mass ratio of the prepolymer 3 to the deionized water is 1:3, and self-emulsifying with an emulsifier to obtain a polyurethane emulsion, wherein the rotation speed of the emulsifier is 5000 r / min, and the emulsification time is 10 min. The obtained polyurethane emulsion is decompressed to remove organic solvents such as acetone, to obtain a polyurethane waterproofing agent.

[0069] The polyurethane waterproofing agents prepared in the above Examples 1-6 and Comparative Example 1 were tested, and the test results are shown in Table 1.

[0070] Table 1

[0071] Test items Waterproof grade Contact angle (°) Particle size (nm) PDI Potential (mV) Example 1 90 95.3 89.5 0.321 64 Example 2 95 97.4 82.6 0.301 63 Example 3 100 100.8 81.3 0.289 66 Example 4 90 96.5 74.3 0.202 67 Example 5 95 99.2 69.8 0.154 66 Example 6 100 102.3 66.5 0.102 69 Comparative Example 1 70 80.7 140.9 0.412 55

[0072] The polyurethane waterproofing agents of the above embodiments and comparative examples were tested according to the following method (implemented in accordance with international standard AATCC22):

[0073] ① Use a measuring cup to measure 250mL (27±1)℃ deionized water and pour it instantly from the top of the funnel;

[0074] ②250mL of water spraying time is completed within 25-30 seconds;

[0075] ③After spraying water, take off the top of the sample frame, tap the other side gently to make the water droplets on the sample fall off, then rotate 180 degrees and tap the other side;

[0076] ④ The tested specimens should be immediately compared with the rating chart and rated;

[0077] ⑤ Repeat the above steps to test and rate other samples, and also perform static contact angle test.

[0078] From the comparison of the experimental data in Table 1, it can be found that the polyurethane waterproofing agent prepared by the present invention has a good waterproofing effect. From the comparison of the experimental data of Examples 1-3 and Comparative Example 1, it can be found that as the GMS content increases, the waterproofing effect becomes better and the contact angle becomes larger. This is because stearyl glycerol GMS contains a long-chain hydrophobic alkane group and has a good hydrophobic effect; the particle size of Examples 1-3 is smaller than that of Comparative Example 1, and as the GMS content increases, the particle size becomes smaller. This is because the hydrophobicity of the molecular chain increases and the mutual entanglement between the molecular chains decreases, thereby increasing the number of latex particles and reducing the size of the particles; Examples 1-3 and Examples 4-6 are compared respectively. The smaller the particle size and the smaller the PDI, indicating that the use of FNP continuous emulsification is beneficial to the preparation of polyurethane, and the obtained waterproofing agent is more stable and more uniform; when the Zeta potential value is greater than 50mV, the emulsion stability is better.

[0079] In summary, the polydimethylsiloxane in the present invention has high silicon-oxygen bond energy, low surface energy and molecular chain flexibility, and can provide good heat resistance, weather resistance, and waterproofness; trimethylolpropane is a triol, which is introduced into waterborne polyurethane to provide a branched structure; monostearate contains a long-chain hydrophobic alkane group, and introducing it into the waterproofing agent can increase the content of long-chain alkanes in the molecule and the hydrophobicity of the fabric; it is environmentally friendly, biodegradable, and will not exist in the environment for a long time; it is safer for the human body and the ecosystem; the production process is cleaner and reduces the emission of hazardous waste; it meets the increasingly stringent environmental protection regulations of various countries and has the advantages of the waterproofing effect can reach level 4-5.

[0080] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for preparing a polyurethane waterproofing agent containing long-chain alkanes, characterized in that: The following steps are involved: (1) in a nitrogen atmosphere, toluene diisocyanate, polydimethylsiloxane and n-propane are added to a container equipped with a mechanical stirrer, a thermometer and a reflux condenser with a drying tube, and vacuum dried at high temperature until the raw materials contain no moisture, and the polymerization reaction temperature is controlled in an anhydrous environment to stir the mixture for 3 to 4 hours to obtain an NCO-terminated prepolymer 1; (2) in a nitrogen atmosphere, dry glyceryl monostearate and catalyst dibutyltin dilaurate are added to the prepolymer 1 obtained in step (1) under controlled temperature, diluted with acetone, and the temperature is lowered. An acetone solution of N-methyldiethanolamine as a cationic chain extender is slowly added dropwise to the container under controlled stirring speed to react, and some acetone is added to the system to adjust the viscosity of the mixture during the reaction, and butanone oxime is added thereto. The reaction is continued for 0.5 to 1 hour to obtain a prepolymer 2; (3) Controlling the temperature, adding glacial acetic acid to the prepolymer 2 obtained in step (2), acidifying to obtain prepolymer 3, adding deionized water, and preparing a polyurethane emulsion by an emulsifier or FNP self-emulsification, and decompressing the polyurethane emulsion to remove organic solvents such as acetone, thereby obtaining the polyurethane waterproofing agent containing long-chain alkanes.

2. The method for preparing a polyurethane waterproofing agent containing long-chain alkanes according to claim 1, characterized in that: In step (1), the polydimethylsiloxane is selected from one of hydroxymethyl polydimethylsiloxane, hydroxyethyl polydimethylsiloxane and hydroxypropyl polydimethylsiloxane.

3. The method for preparing a polyurethane waterproofing agent containing long-chain alkanes according to claim 1, characterized in that: In step (1), the concentration of n-propane is 1wt% to 2wt%, the polymerization reaction temperature is 75 to 90°C, the stirring speed is 150 to 220 r / min, and the molar ratio of -NCO / -OH of the reactants in the polymerization reaction is 1.2 to 1.

6.

4. The method for preparing a polyurethane waterproofing agent containing long-chain alkanes according to claim 1, characterized in that: In step (1), the temperature of vacuum drying at high temperature until the raw material contains no moisture is controlled to be 105-115°C.

5. The method for preparing a polyurethane waterproofing agent containing long-chain alkanes according to claim 1, characterized in that: In step (2), the concentration of the glyceryl monostearate is 10wt% to 20wt%, the concentration of the catalyst dibutyltin dilaurate is 0.01wt% to 0.02wt%, the controlled temperature is 40 to 50°C, and the temperature is lowered to 20 to 30°C.

6. The method for preparing a polyurethane waterproofing agent containing long-chain alkanes according to claim 1, characterized in that: In step (2), N-methyldiethanolamine and acetone are diluted in a mass ratio of 1 to 5 and slowly added dropwise, and the stirring speed is controlled to be 150 to 220 r / min.

7. The method for preparing a polyurethane waterproofing agent containing long-chain alkanes according to claim 1, characterized in that: In step (2), butanone oxime is added in an amount equal to the molar number of the remaining NCO groups, and at the same time, glacial acetic acid is added in an amount equal to the molar number of the N-methyldiethanolamine in step 2.

8. The method for preparing a polyurethane waterproofing agent containing long-chain alkanes according to claim 1, characterized in that: In step (3), the controlled temperature is 20-25° C., the mass ratio of the prepolymer 3 to deionized water is 1-3:1-4, the rotation speed of the emulsifier is 4800-5000 r / min, and the emulsification time is 8-10 min.

9. The method for preparing a polyurethane waterproofing agent containing long-chain alkanes according to claim 1, characterized in that: In step (3), the FNP self-emulsification is prepared by using instantaneous nanoprecipitation technology FNP, using a microreactor, taking prepolymer 3 as stream No. 1 and deionized water as stream No. 2, flushing prepolymer 3 into the tiny cavity of the microreactor for rapid and uniform mixing to prepare a polyurethane emulsion.

10. A polyurethane waterproofing agent containing long-chain alkanes prepared by the method for preparing a polyurethane waterproofing agent containing long-chain alkanes according to any one of claims 1 to 9.

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