Bio-based PDI waterborne polyurethane emulsion as well as preparation method and application thereof

Abstract

The invention discloses a bio-based PDI waterborne polyurethane emulsion, which is prepared from a system formed by the following components in parts by weight: 70 to 90 parts of first bio-based polyol, 30 to 50 parts of second bio-based polyol, 25 to 45 parts of 1, 5-pentamethylene diisocyanate, 0.5 to 2.5 parts of catalyst and 4 to 6 parts of neutralizer, wherein the first bio-based polyol and the second bio-based polyol are respectively selected from any one of polyethylene glycol, polycarbonate diol or polylactic acid polyol. The bio-based PDI water-based polyurethane emulsion is prepared by taking the first bio-based polyol, the second bio-based polyol and the 1, 5-pentamethylene diisocyanate as raw materials, so that the bio-based proportion is enlarged, the emulsion is green and environment-friendly, and the emulsion has good stability and has relatively good thermal stability and tensile strength after being cured into a film. The bio-based PDI waterborne polyurethane emulsion provided by the invention can be applied to a printing coating, and a fabric treated by the printing coating is bright in color and soft in hand feeling.

Description

Technical Field

[0001] The invention relates to a waterborne polyurethane material, and in particular to a bio-based PDI waterborne polyurethane emulsion and a preparation method and application thereof. Background Art

[0002] With the depletion of oil resources and the popularization of green ecological development concepts, in order to reduce dependence on traditional petrochemical resources and reduce carbon emissions, bio-based products are gradually replacing traditional oil resources, and the proportion of water-based polyurethane in the paint printing industry is increasing year by year.

[0003] 1,5-pentane diisocyanate (PDI) is made from biomass such as corn stalks, and its additives such as rice bran wax also come from renewable resources such as corn and castor, making it a green material. PDI has excellent properties such as high strength, high toughness, oil resistance, and yellowing resistance, and is environmentally friendly and low in toxicity. However, the waterborne polyurethane emulsion prepared with PDI as the hard segment in the prior art has weak stability and low tensile strength after curing into a film, so it is difficult to use it as a coating for paint printing. Summary of the invention

[0004] The first object of the present invention is to provide a bio-based PDI aqueous polyurethane emulsion to solve at least one of the above technical problems.

[0005] The second object of the present invention is to provide a method for preparing a bio-based PDI aqueous polyurethane emulsion to solve at least one of the above technical problems.

[0006] The third object of the present invention is to provide a bio-based PDI printing coating to solve at least one of the above-mentioned technical problems.

[0007] According to a first aspect of the present invention, a bio-based PDI waterborne polyurethane emulsion is provided, wherein the bio-based PDI waterborne polyurethane emulsion is prepared from a system formed by the following components in parts by weight: 70 to 90 parts of a first bio-based polyol, 30 to 50 parts of a second bio-based polyol, 25 to 45 parts of 1,5-pentanediisocyanate, 0.5 to 2.5 parts of a catalyst, and 4 to 6 parts of a neutralizer;

[0008] Wherein, the first bio-based polyol and the second bio-based polyol are respectively selected from any one of polyethylene glycol, polycarbonate diol or polylactic acid polyol.

[0009] The bio-based PDI aqueous polyurethane emulsion according to the present invention has good emulsion stability. 1,5-pentanediisocyanate and a variety of bio-based polyols are used to prepare a bio-based PDI aqueous polyurethane emulsion with a high bio-based content, which has good thermal stability and tensile strength after being cured into a film.

[0010] In some embodiments, the number average molecular weight of polypropylene glycol can be 600 to 3000, the number average molecular weight of polycarbonate diol can be 500 to 3000, and the number average molecular weight of polylactic acid polyol can be 1000 to 2000. By adjusting the combination, number average molecular weight and content of bio-based polyols, a bio-based PDI waterborne polyurethane emulsion that meets mechanical properties after curing and film formation is obtained.

[0011] In some embodiments, the neutralizing agent may be any one of triethylamine, dimethylaminoethanol or triethanolamine.

[0012] In some embodiments, the molar ratio of the neutralizing agent to the carboxyl group in the reaction system is (0.9-1.1):1.

[0013] In some embodiments, the catalyst may be at least one of organic bismuth or bismuth neodecanoate. Specifically, the catalyst may be bismuth neodecanoate DY-20, the bismuth content of which is 20%±0.5.

[0014] In some embodiments, the system further comprises 2 to 10 parts by weight of a hydrophilic chain extender.

[0015] In some embodiments, the hydrophilic chain extender may be at least one of 2,2-dimethylol propionic acid, 2,2-dimethylol butyric acid, and tartaric acid glyceride.

[0016] In some embodiments, the system further comprises 6 to 11 parts by weight of a small molecule chain extender.

[0017] In some embodiments, the small molecule chain extender can be any one or two of PEG, diethylenediamine, ethylenediamine, and isophoronediamine. Specifically, the number average molecular weight of PEG can be 200 to 600. PEG is used as both a small molecule chain extender and a compatibilizer in the system to improve the problem of uneven compatibility reaction between polycarbonate diol as a soft segment and PDI and a hydrophilic chain extender.

[0018] According to a second aspect of the present invention, a method for preparing a bio-based PDI waterborne polyurethane emulsion is provided.

[0019] In some embodiments, the method for preparing a bio-based PDI waterborne polyurethane emulsion comprises the following steps:

[0020] S1. Add the first bio-based polyol and the second bio-based polyol into a reactor, and perform a reduced pressure dehydration reaction in a nitrogen atmosphere, then cool to 60° C. to 70° C., add 1,5-pentanediisocyanate and a catalyst into the reactor, react at a constant temperature of 80° C. to 85° C. for 1.5 to 3 hours, then add an organic solvent, and cool to 45 to 55° C. to obtain a bio-based PDI polyurethane prepolymer;

[0021] S2, adding a neutralizing agent to the bio-based PDI polyurethane prepolymer for neutralization for 8 to 12 minutes, adding deionized water for emulsification reaction, and removing the organic solvent in vacuo at 40 to 50° C. to obtain;

[0022] In other embodiments, the method for preparing the bio-based PDI waterborne polyurethane emulsion comprises the following steps:

[0023] S1. Add the first bio-based polyol and the second bio-based polyol into a reactor, and perform a reduced pressure dehydration reaction in a nitrogen atmosphere, then cool down to 60°C to 70°C, add 1,5-pentanediisocyanate into the reactor, react at 80°C to 85°C for 1.5 to 3 hours, cool down to 55°C to 65°C, then add a catalyst and a chain extension agent into the reactor, react at 60°C to 80°C for 3 to 5 hours, then add an organic solvent, cool down to 45 to 55°C, and obtain a bio-based PDI polyurethane prepolymer;

[0024] S2, adding a neutralizing agent to the bio-based PDI polyurethane prepolymer for neutralization for 8 to 12 minutes, adding deionized water for emulsification reaction, and removing the organic solvent in vacuo at 40 to 50° C. to obtain;

[0025] Wherein, the chain extender is at least one of a hydrophilic chain extender and a small molecule chain extender.

[0026] In some embodiments, the organic solvent may be any one of acetone or butanone.

[0027] In some embodiments, in step S1, the reduced pressure dehydration treatment method is reduced pressure dehydration for 1 to 2 hours at a temperature of 100 to 120° C. and a vacuum degree greater than 0.085 MPa.

[0028] In some embodiments, the emulsification reaction in step S2 is first dispersed at a rotation speed of 1800 to 2200 r / min for 4 to 6 minutes, and then dispersed at a rotation speed of 900 to 1100 r / min for 0.8 to 1.2 hours.

[0029] In other embodiments, the processing method of the emulsification reaction in step S2 is to add a neutralizer to the bio-based PDI polyurethane prepolymer for neutralization, first add a small molecule chain extender, then add deionized water, disperse at a speed of 1800 to 2200 r / min for 4 to 6 minutes, and then disperse at a speed of 900 to 1100 r / min for 0.8 to 1.2 hours.

[0030] In other embodiments, the processing method of the emulsification reaction in step S2 is to add a neutralizer to the bio-based PDI polyurethane prepolymer for neutralization, first add a small molecule chain extender, then add deionized water, disperse at a speed of 1800 to 2200 r / min for 4 to 6 minutes, and then disperse at a speed of 900 to 1100 r / min for 0.8 to 1.2 hours.

[0031] According to a third aspect of the present invention, there is provided a use of a bio-based PDI waterborne polyurethane emulsion in a printing coating.

[0032] The bio-based PDI waterborne polyurethane emulsion according to the present invention can be formulated into a printing coating, which can be applied to the surface of a fabric by a mechanical or manual method. The fabric treated with the printing coating has bright colors, no obvious fading after overheating, and a soft feel.

[0033] In some embodiments, the printing coating includes the following components, in parts by weight: 80 to 90 parts of the bio-based PDI waterborne polyurethane emulsion, 0.5 to 1.5 parts of a defoamer, 2 to 4 parts of a thickener, and 8 to 12 parts of a color paste.

[0034] The beneficial effects of the present invention include:

[0035] (1) The bio-based PDI waterborne polyurethane emulsion of the present invention is prepared using a first bio-based polyol, a second bio-based polyol and 1,5-pentanediisocyanate as raw materials, which reduces the use of non-renewable petroleum resources and is a green and environmentally friendly material; and the prepared bio-based PDI waterborne polyurethane emulsion has good stability and good tensile strength and thermal stability after being cured into a film;

[0036] (2) The bio-based PDI aqueous polyurethane emulsion of the present invention can be applied to printing coatings. The fabrics treated with the printing coatings are brightly colored and soft to the touch. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 This is an infrared spectrum of the bio-based PDI waterborne polyurethane emulsion prepared by the preparation method of Examples 1 to 4 of the present invention;

[0038] Figure 2 This is a particle size curve of the bio-based PDI waterborne polyurethane emulsion prepared by the preparation methods of Examples 1 to 4 of the present invention;

[0039] Figure 3 The stress-strain curve of the WPU cured film after the bio-based PDI waterborne polyurethane emulsion prepared by the preparation method of Examples 1 to 4 of the present invention is cured to form a film;

[0040] Figure 4 The TGA curve of the WPU cured film after the bio-based PDI waterborne polyurethane emulsion prepared by the preparation method of Examples 1 to 4 of the present invention is cured to form a film;

[0041] Figure 5 The DTG curve of the WPU cured film after the bio-based PDI waterborne polyurethane emulsion prepared by the preparation method of Examples 1 to 4 of the present invention is cured to form a film;

[0042] Figure 6 (A) A physical picture of the printing paint of Example 5 of the present invention applied on cotton cloth; Figure 6 (B) is a physical picture of the printing paint of Example 6 of the present invention applied on cotton cloth; Figure 6 (C) is a physical picture of the printing paint of Example 7 of the present invention applied on cotton cloth; Figure 6 (D) is a physical picture of the printing coating of Example 8 of the present invention applied on cotton cloth;

[0043] Figure 7 (A) A photo of the printing coating of Example 5 of the present invention applied on a swimsuit fabric; Figure 7 (B) is a photo of the printed coating of Example 6 of the present invention applied on a swimsuit; Figure 7 (C) is a real picture of the printing coating of Example 7 of the present invention applied on a swimsuit; Figure 7 (D) is a photo of the printed coating of Example 8 of the present invention applied on a swimsuit fabric. DETAILED DESCRIPTION

[0044] The present invention is further described in detail below in conjunction with the accompanying drawings, but the embodiments of the present invention are not limited thereto. The raw materials and reagents involved in the following examples can all be obtained from commercial channels.

[0045] Example 1

[0046] This embodiment provides a method for preparing a bio-based PDI waterborne polyurethane emulsion, comprising the following steps:

[0047] In a nitrogen atmosphere, 80 parts of bio-based PPG (number average molecular weight of 2000) and 40 parts of bio-based PCD (number average molecular weight of 1000) were added to the reactor, and the reaction was carried out under reduced pressure and dehydration at a temperature of 115°C and a vacuum degree greater than 0.085MPa for 2 hours. The temperature was lowered to 65°C, 30 parts of PDI were added to the reactor, and the reaction was carried out at a constant temperature of 85°C for 2 hours, and then the temperature was lowered to 60°C, and 8 parts of DMPA, 4 parts of PEG (number average molecular weight of 400) and 2 parts of bismuth neodecanoate were added, and the temperature was raised to The mixture was reacted at a constant temperature of 75°C for 5 hours, acetone was added to adjust the viscosity of the system, the temperature was lowered to 50°C, and triethylamine in an amount equimolar to the carboxyl group in the reaction system was added to the reactor for neutralization reaction for 10 minutes. 200 g of deionized water was added, and the mixture was dispersed in a high-speed disperser at a speed of 2000 r / min for 5 minutes. 2.8 parts of diethylenediamine were added, and the mixture was dispersed in a high-speed disperser at a speed of 1000 r / min for 1 hour. After the emulsification reaction was completed, the acetone was removed in a vacuum environment at 45°C to obtain the product.

[0048] The product obtained in Example 1 was subjected to infrared detection, and the infrared spectrum was as follows: Figure 1 As shown. Figure 1 It can be seen that at 2270cm -1 The characteristic absorption peak at 2971.761 cm-1 disappeared (-N=C=O), indicating that the hydroxyl groups of PPG and PCD reacted completely with the isocyanate groups in PDI. -1 The stretching vibration peaks of -CH2 and -CH3 are at 1725.978 cm -1 The stretching vibration peak of C=O is at 1255cm -1 and 1166cm -1 The appearance of -COO stretching vibration peak indicated that the bio-based PDI waterborne polyurethane emulsion was successfully synthesized.

[0049] Example 2

[0050] This embodiment provides a method for preparing a bio-based PDI waterborne polyurethane emulsion, comprising the following steps:

[0051] In a nitrogen atmosphere, 80 parts of bio-based PPG (number average molecular weight of 2000) and 40 parts of bio-based PCD (number average molecular weight of 1000) were added to the reactor, and the reaction was carried out under reduced pressure and dehydration at a temperature of 115°C and a vacuum degree greater than 0.085MPa for 2 hours. The temperature was lowered to 65°C, and 30 parts of PDI were added to the reactor. After the reaction was kept at 85°C for 2 hours, the temperature was lowered to 60°C, and 9 parts of tartaric acid glyceride, 8 parts of PEG (number average molecular weight of 400) and 0.5 parts of Bismuth neodecanoate was heated to 70°C and reacted at a constant temperature for 3 hours, acetone was added to adjust the viscosity of the system, the temperature was lowered to 50°C, and then triethylamine in an amount equimolar to the carboxyl group in the reaction system was added to the reactor for neutralization reaction for 10 minutes, and then 200g of deionized water was added, and the mixture was dispersed in a high-speed disperser at a speed of 2000r / min for 5 minutes, and then dispersed in a high-speed disperser at a speed of 1000r / min for 1 hour. After the emulsification reaction was completed, the acetone was removed in a vacuum environment at 45°C to obtain the product.

[0052] The product obtained in Example 2 was subjected to infrared detection, and the infrared spectrum was as follows: Figure 1 As shown, from Figure 1 It can be seen that the position of its characteristic peak is basically consistent with that in Example 1, which also shows that the bio-based PDI water-based polyurethane emulsion in Example 2 was successfully synthesized.

[0053] Example 3

[0054] This embodiment provides a method for preparing a bio-based PDI waterborne polyurethane emulsion, comprising the following steps:

[0055] In a nitrogen atmosphere, 80 parts of bio-based PPG (number average molecular weight of 2000) and 40 parts of polylactic acid polyol (number average molecular weight of 1000) were added to a reactor, and the reaction was carried out under reduced pressure and dehydration at a temperature of 115°C and a vacuum degree greater than 0.085MPa for 2 hours, and the temperature was lowered to 65°C. 40 parts of PDI and 0.5 parts of bismuth neodecanoate were added to the reactor, and the temperature was raised to 85°C for constant temperature reaction for 2 hours. 8 parts of DMPA and 30 parts of acetone were added to adjust the viscosity of the system, and the temperature was lowered to 50°C. Then, triethylamine in an amount equimolar to the carboxyl group in the reaction system was added to the reactor for neutralization reaction for 10 minutes, and then 250g of deionized water and 4.5 parts of ethylenediamine were added. The mixture was dispersed in a high-speed disperser at a speed of 2000r / min for 5 minutes, and then dispersed in a high-speed disperser at a speed of 1000r / min for 1 hour. After the emulsification reaction was completed, the acetone was removed in a vacuum environment of 45°C to obtain the product.

[0056] The product obtained in Example 3 was subjected to infrared detection, and the infrared spectrum was as follows: Figure 1 As shown, from Figure 1It can be seen that the position of its characteristic peak is basically consistent with that in Example 1, indicating that the hydroxyl groups of PPG and polylactic acid polyol react completely with the isocyanate groups in PDI, and also indicating that the bio-based PDI waterborne polyurethane emulsion in Example 3 is successfully synthesized.

[0057] Example 4

[0058] This embodiment provides a method for preparing a bio-based PDI waterborne polyurethane emulsion, comprising the following steps:

[0059] In a nitrogen atmosphere, 80 parts of polylactic acid polyol (number average molecular weight of 2000) and 40 parts of bio-based PCD (number average molecular weight of 1000) were added to a reactor, and the reaction was carried out under reduced pressure and dehydration at a temperature of 115°C and a vacuum degree greater than 0.085 MPa for 2 hours. The temperature was lowered to 65°C, 40 parts of PDI were added to the reactor, and the reaction was carried out at 85°C for 2 hours, then the temperature was lowered to 60°C, and 6.8 parts of methyl propanediol and 2 parts of bismuth neodecanoate were added. The temperature was raised to 75°C and the reaction was carried out at a constant temperature for 2 hours. Acetone was added to adjust the viscosity of the system, and the temperature was lowered to 50°C. Then, triethylamine in an amount equimolar to the carboxyl group in the reaction system was added to the reactor for neutralization reaction for 10 minutes, and then 250 g of deionized water was added. The mixture was dispersed at a high speed of 2000 r / min for 5 minutes, and then dispersed at a low speed of 1000 r / min for 1 hour. After the emulsification reaction was completed, the acetone was removed in a vacuum environment of 45°C to obtain the product.

[0060] The product obtained in Example 4 was subjected to infrared detection, and the infrared spectrum was as follows: Figure 1 As shown, from Figure 1 It can be seen that the position of its characteristic peak is basically consistent with that in Example 1, indicating that the hydroxyl groups of polylactic acid polyol and PCD react completely with the isocyanate groups in PDI, and also indicating that the bio-based PDI waterborne polyurethane emulsion in Example 4 is successfully synthesized.

[0061] Example 5

[0062] This embodiment provides a printing coating, and the preparation method is as follows: by weight, 90 parts of the bio-based PDI water-based polyurethane emulsion prepared in Example 1, 1 part of defoamer 580, 3 parts of thickener N-0010, 0.8 parts of pH regulator AMP95 and 10 parts of bright red paste are mixed to obtain a printing coating.

[0063] Example 6

[0064] This embodiment provides a printing coating, and the preparation method is as follows: by weight, 90 parts of the bio-based PDI water-based polyurethane emulsion prepared in Example 2, 1 part of defoamer 580, 3 parts of thickener N-0010 and 10 parts of bright red paste are mixed to obtain a printing coating.

[0065] Example 7

[0066] This embodiment provides a printing coating, and the preparation method is as follows: by weight, 90 parts of the bio-based PDI water-based polyurethane emulsion prepared in Example 3, 1 part of defoamer 580, 3 parts of thickener N-0010 and 10 parts of bright red paste are mixed to obtain a printing coating.

[0067] Example 8

[0068] The present embodiment provides a printing coating, and the preparation method is as follows: by weight, 90 parts of the bio-based PDI water-based polyurethane emulsion prepared in Example 4, 1 part of defoamer 580, 1.4 parts of thickener N-0010, 3 parts of propylene glycol, 0.8 parts of pH regulator AMP95, 10 parts of bright red paste and 1 part of cross-linking agent carbodiimide are mixed to obtain a printing coating.

[0069] Experimental Example 1

[0070] In this experimental example, the bio-based PDI waterborne polyurethane emulsion prepared in Examples 1 to 4 was tested for particle size distribution and zeta potential. The particle size distribution results are as follows: Figure 2 The values ​​of Zeta potential are shown in Table 1. Figure 2 It can be seen that the average particle size and particle size distribution of the bio-based PDI aqueous polyurethane emulsions prepared in Examples 1 to 4 are relatively close, with an average particle size of about 200 nm. The particle size of the bio-based PDI aqueous polyurethane emulsions in Examples 1 and 4 is slightly larger than that of the bio-based PDI aqueous polyurethane emulsions in Examples 2 and 3. As can be seen from Table 1, the absolute values ​​of the Zeta potential of the bio-based PDI aqueous polyurethane emulsions prepared in Examples 1 to 4 are all greater than 50, indicating that the bio-based PDI aqueous polyurethane emulsions prepared by the preparation method of the present invention have good storage stability. The maximum absolute value of the Zeta potential of Examples 1 and 2 is greater than that of Examples 3 and 4. This is because Examples 1 and 2 use PEG as a small molecule chain extender in combination with a hydrophilic chain extender, making the bio-based prepolymer easy to emulsify, and improving the problem of easy demulsification in the acetone method due to the hydrophobicity of PCD and the reaction with the hydrophilic chain extender. The Zeta potential of Example 2 is greater than that of Example 1. This is because the hydrophilic chain extender of Example 2 has a lower melting point and diffuses faster in the reaction system, thus promoting the chain extension reaction.

[0071] Table 1 Zeta potential of bio-based PDI waterborne polyurethane emulsion

[0072] sample Zeta potential (mV) Example 1 59.3±4.24 Example 2 69.4±2.31 Example 3 50.7±2.43 Example 4 50.2±1.32

[0073] Experimental Example 2

[0074] 10 g of the bio-based PDI waterborne polyurethane emulsion prepared in Examples 1 to 4 were weighed respectively and placed in a culture dish. The culture dish was dried at room temperature for 24 h, and then placed in an electric constant temperature blast drying oven at 60° C. and dried for 12 h to obtain a cured film.

[0075] In this experimental example, the bio-based PDI waterborne polyurethane emulsion prepared in Examples 1 to 4 was cured to obtain a cured film and the tensile properties were tested. Figure 3 As shown. Figure 3 It can be seen that when the relative deformation of the cured film is the same, the stress of the cured film of Example 3 and Example 4 is significantly greater than that of Example 1 and 2. This is because Examples 3 and 4 use polylactic acid polyols and other raw materials to prepare bio-based PDI waterborne polyurethanes, indicating that the bio-based PDI waterborne polyurethane emulsion prepared using bio-based PPG and bio-based PCD as soft segments has better tensile strength after curing into a film. By controlling the combination and relative content of bio-based polyols, a bio-based PDI waterborne polyurethane cured film with desired tensile properties can be formulated.

[0076] Experimental Example 3

[0077] In this experimental example, the thermal stability of the cured film obtained by curing the bio-based PDI waterborne polyurethane emulsion prepared in Examples 1 to 4 was analyzed. The results are as follows: Figure 4 and Figure 5 As shown, the cured films of different embodiments were placed at a thermal degradation temperature (T 5％ ), 50% thermal degradation temperature (T 50％ ), maximum degradation rate temperature (T max ) and the carbon residue rate at 700℃ are listed in Table 2.

[0078] from Figure 4 and Figure 5 It can be seen that the thermal degradation of the cured film can be roughly divided into two stages. The first stage is the degradation of the hard segment at a temperature of about 300°C, and the second stage is the degradation of the soft segment at a temperature of about 400°C, indicating that the cured films of Examples 1 to 4 have good thermal stability. As can be seen from Table 2, the thermal degradation temperature of the cured films of Examples 1 and 3 at a weight loss of 50% is greater than 300°C, indicating that they have good heat resistance. This is because the reaction systems of Examples 1 and 3 react more fully, and the increase in crosslinking degree and molecular weight restricts the movement of the molecular chains of the products, thereby making T 50％At the same time, the carbon residue rate of Example 1 and Example 3 at 700°C is relatively low, because the cured films of Example 1 and Example 3 are more likely to generate gas products during thermal degradation. Although the weight loss of the cured films of Example 2 and Example 4 reaches 50% at about 250°C, the carbon residue rate at 700°C is greater than 9%, because compared with other embodiments of the present invention, the cured films of Example 2 and Example 4 first undergo segment cleavage and release of small molecules at a lower temperature, and then undergo carbonization reaction at a higher temperature.

[0079] Table 2 Thermal decomposition data of cured films

[0080] sample <![CDATA[T 5％ (℃)]]> <![CDATA[T 50％ (℃)]]> <![CDATA[T max (1 st / 2 nd )(℃)]]> Carbon residue rate (%) Example 1 233.8 303.3 342.7 / 400.8 2.44 Example 2 237.9 264.4 316.4 / 380.4 10.64 Example 3 278.7 307.2 324.2 / 396.7 0.79 Example 4 242.3 266.3 291.8 / 377.8 9.53

[0081] Experimental Example 4

[0082] In this experimental example, the printing coatings of Examples 5 to 8 were applied to cotton cloth and swimsuit cloth respectively, and then the cotton cloth and swimsuit cloth were overheated at 135°C for 30 seconds. The color degree of the printing on the cotton cloth before and after overheating was observed by visual inspection. The results are as follows: Figure 6 and Figure 7 As shown, it can be observed that the printing paint of the present invention is brightly colored when applied on cotton cloth, and there is no obvious fading after overheating at 135°C, indicating that the printing paint has good thermal stability and can be printed on fabrics. By touching the fabric, it is found that the fabric treated with the printing paint feels soft.

[0083] The machine washing fastness test of the swimsuit fabric coated with the printed coating was carried out according to GB / T 3921-2008 "Textiles - Tests for Colour Fastness - Colour Fastness to Soaping". The experimental conditions of the test were as follows: the swimsuit fabric coated with the printed coating of Examples 5 to 8 was immersed in water, 5g of phosphorus-free washing powder was added, and the fabric was washed in a mechanical washing device at a water temperature of 60°C and a rotation speed of 1200r / min for a standard 2.5h.

[0084] According to the test method for color fastness to rubbing (dry and wet) in GB / T 3920-2008 “Textiles - Tests for color fastness - Color fastness to rubbing”, the cotton cloth coated with the printing coatings of Examples 5 to 8 was tested for dry and wet rubbing fastness.

[0085] Table 3 Dry rubbing fastness, wet rubbing fastness and machine washing fastness of fabrics

[0086] Dry rubbing fastness Wet rubbing fastness Machine washing fastness Example 5 4 4-5 4 Example 6 3-4 3-4 3-4 Example 7 3-4 4 4 Example 8 3-4 4 3-4

[0087] As can be seen from Table 3, the swimsuit fabric coated with the printed coatings of Examples 5 to 8 was rated 3-4 after the machine washing fastness test, indicating that the printed coating was firmly bonded to the swimsuit fabric (generally chemical fiber). The cotton fabric coated with the printed coatings of Examples 5 to 8 was rated 3-4 in the dry friction fastness test, indicating that the printed coating of the present invention has a strong bond with the cotton fiber and is not easy to fall off due to friction, and the wet friction fastness was rated 3-5, indicating that the printed coating is not easily dissolved by water. The above tests show that the printed coating slurry of the present invention has good adhesion and water resistance and can be coated on fabrics.

[0088] Therefore, compared with the prior art, the beneficial effects of the present invention are as follows: the bio-based PDI water-based polyurethane emulsion prepared by reacting the first bio-based polyol, the second bio-based polyol and 1,5-pentanediisocyanate reduces the use of petroleum resources as raw materials, increases the content of bio-based in the water-based polyurethane emulsion, and is green and environmentally friendly. At the same time, the bio-based PDI water-based polyurethane emulsion prepared by the present invention has good emulsion stability. In addition, the cured film of the bio-based PDI water-based polyurethane emulsion of the present invention after curing and film formation has good tensile properties and thermal stability. The bio-based PDI water-based polyurethane emulsion of the present invention can be used to prepare printing coatings, and the fabrics treated with the printing coatings have bright colors and soft hand feel, and the machine washing fastness test and dry and wet friction fastness test results are good.

[0089] The above are only some embodiments of the present invention. For those skilled in the art, several modifications and improvements can be made without departing from the creative concept of the present invention, which all belong to the protection scope of the present invention.

Claims

1. A bio-based PDI waterborne polyurethane emulsion, characterized in that: The system is prepared from the following components in parts by weight: 70 to 90 parts of a first bio-based polyol, 30 to 50 parts of a second bio-based polyol, 25 to 45 parts of 1,5-pentanediisocyanate, 0.5 to 2.5 parts of a catalyst, and 4 to 6 parts of a neutralizer; Wherein, the first bio-based polyol and the second bio-based polyol are respectively selected from any one of polyethylene glycol, polycarbonate diol or polylactic acid polyol.

2. The bio-based PDI aqueous polyurethane emulsion according to claim 1, characterized in that The neutralizing agent is any one of triethylamine, dimethylaminoethanol or triethanolamine, and the molar ratio of the neutralizing agent to the carboxyl group in the system is (0.9-1.1):1; the catalyst is at least one of organic bismuth or bismuth neodecanoate.

3. The bio-based PDI aqueous polyurethane emulsion according to claim 2, characterized in that: The system further comprises 2 to 10 parts by weight of a hydrophilic chain extender, wherein the hydrophilic chain extender is at least one of 2,2-dihydroxymethyl propionic acid, 2,2-dihydroxymethyl butyric acid, and tartaric acid glyceride.

4. The bio-based PDI aqueous polyurethane emulsion according to any one of claims 1 to 3, characterized in that The system further comprises 6 to 11 parts by weight of a small molecule chain extender, wherein the small molecule chain extender is any one or two of PEG, diethylenediamine, ethylenediamine, and hydrazine hydrate.

5. The method for preparing the bio-based PDI aqueous polyurethane emulsion according to claim 1 or 2, characterized in that: The preparation method comprises the following steps: S1. Add the first bio-based polyol and the second bio-based polyol into a reactor, and perform a reduced pressure dehydration reaction in a nitrogen atmosphere, then cool to 60° C. to 70° C., add 1,5-pentanediisocyanate and a catalyst into the reactor, react at a constant temperature of 80° C. to 85° C. for 1.5 to 3 hours, then add an organic solvent, and cool to 45 to 55° C. to obtain a bio-based PDI polyurethane prepolymer; S2, adding a neutralizing agent to the bio-based PDI polyurethane prepolymer for neutralization for 8 to 12 minutes, adding deionized water for emulsification reaction, and removing the organic solvent in vacuo at 40 to 50° C. to obtain; Wherein, the organic solvent is any one of acetone or butanone.

6. The method for preparing the bio-based PDI aqueous polyurethane emulsion according to claim 3 or 4, characterized in that: The preparation method comprises the following steps: S1. Add the first bio-based polyol and the second bio-based polyol into a reactor, and perform a reduced pressure dehydration reaction in a nitrogen atmosphere, then cool down to 60°C to 70°C, add 1,5-pentanediisocyanate into the reactor, react at 80°C to 85°C for 1.5 to 3 hours, cool down to 55°C to 65°C, then add a catalyst and a chain extension agent into the reactor, react at 60°C to 80°C for 3 to 5 hours, then add an organic solvent, cool down to 45 to 55°C, and obtain a bio-based PDI polyurethane prepolymer; S2, adding a neutralizing agent to the bio-based PDI polyurethane prepolymer for neutralization for 8 to 12 minutes, adding deionized water for emulsification reaction, and removing the organic solvent in vacuo at 40 to 50° C. to obtain; Wherein, the organic solvent is any one of acetone and butanone; the chain extender is at least one of a hydrophilic chain extender and a small molecule chain extender.

7. The method for preparing the bio-based PDI aqueous polyurethane emulsion according to claim 5 or 6, characterized in that: In step S1, the decompression dehydration treatment method is to dehydrate under reduced pressure for 1 to 2 hours at a temperature of 100 to 120° C. and a vacuum degree greater than 0.085 MPa.

8. The method for preparing the bio-based PDI aqueous polyurethane emulsion according to claim 5 or 6, characterized in that: In step S2, the processing method of the emulsification reaction is: First disperse at a speed of 1800-2200 r / min for 4-6 minutes, then add a small molecule chain extender, and then disperse at a speed of 900-1100 r / min for 0.8-1.2 hours. Or, first disperse at a speed of 1800-2200 r / min for 4-6 min, and then disperse at a speed of 900-1100 r / min for 0.8-1.2 h; Alternatively, after neutralizing the bio-based PDI polyurethane prepolymer with a neutralizing agent, first add a small molecule chain extender, then add deionized water, disperse at a speed of 1800-2200 r / min for 4-6 minutes, and then disperse at a speed of 900-1100 r / min for 0.8-1.2 hours.

9. Use of the bio-based PDI aqueous polyurethane emulsion according to any one of claims 1 to 4 in printing coatings.

10. The use according to claim 9, characterized in that: The printing coating comprises the following components in parts by weight: 80 to 90 parts of the bio-based PDI waterborne polyurethane emulsion, 0.5 to 1.5 parts of a defoamer, 2 to 4 parts of a thickener and 8 to 12 parts of a color paste.

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