Aqueous polyurethane dispersion, preparation method therefor and use thereof

Abstract

The present application provides an aqueous polyurethane dispersion, a preparation method therefor and a use thereof. Raw materials of the aqueous polyurethane dispersion comprise a hydrogenated polybutadiene polyol and a polyisocyanate, wherein the mass percentage content of a hydrogenated 1,2-vinyl unit in the hydrogenated polybutadiene polyol is not higher than 85%. By selecting the hydrogenated polybutadiene polyol as a soft segment and defining the mass percentage content of the hydrogenated 1,2-vinyl unit in the hydrogenated polybutadiene polyol to be not higher than 85%, the obtained aqueous polyurethane dispersion can have both excellent solvent resistance and mechanical properties, have a relatively high modulus, breaking strength, and elongation at break, and can be used as an automotive interior adhesive, an electronic adhesive, or a battery adhesive.

Description

Aqueous polyurethane dispersion and its preparation method and application Technical Field

[0001] The present application belongs to the technical field of polyurethanes, and specifically relates to an aqueous polyurethane dispersion and a preparation method and application thereof. Background Art

[0002] Over the past few decades, waterborne polyurethane dispersions based on polyester, polyether, and polycarbonate polyols as soft segments have been extensively researched and applied by academia and industry. They offer performance comparable to oil-based systems while being environmentally friendly and pollution-free during use, leading to their widespread use in coatings, adhesives, and other fields. Polyester, polyether, and polycarbonate polyurethane or polyurethane-urea aqueous dispersions are often designed as larger molecular weight block polymers. However, these waterborne polyurethanes share a common characteristic: a large number of highly polar ester, ether, and carbonate bonds give the polymer chain segments a high overall polarity, resulting in poor adhesion to low-surface-energy substrates. Furthermore, since most of these soft segments can crystallize and hydrogen bonds exist between them and the hard segments, their low-temperature stability is limited. Furthermore, the large number of polar segments and most polar organic solvents dissolve like in like, leading to challenges in the solvent resistance of polyurethane films, limiting the application scenarios of waterborne polyurethanes.

[0003] At present, there are several methods to improve the above-mentioned problems. For example, the polarity of the polymer can be tuned by low-polarity substrate treatment agents or by introducing silicon-containing or low-polarity side chains into water-based polyurethane, thereby improving its adhesion to low-surface-energy substrates, but the degree of improvement is extremely limited; for example, the crystallization can be destroyed by introducing irregular segments or monomers, thereby improving the low-temperature resistance of the emulsion, but this will sacrifice the high cohesive energy brought by the crystallization to a certain extent; for example, the organic solvent resistance of polyester, polyether, and polycarbonate water-based polyurethane films can be improved by introducing cross-linking or increasing the molecular weight, but this method itself is an unfavorable factor for the film-forming property of the emulsion and needs to be balanced and adjusted as appropriate.

[0004] CN113711383A discloses a binder composition for electrodes that exhibits high durability even when using active materials with large volume changes. The polyurethane resin is obtained by reacting a polyisocyanate, an olefin polyol containing more than 1.5 active hydrogen atoms and / or a carbonate diol having less than 6 carbon atoms between carbonate bonds, a compound having a hydrophilic group and more than one active hydrogen atom, and a chain extender. The obtained resin has excellent electrolyte stability, electrode active material / electrode sheet adhesion, and the ability to inhibit expansion and rebound of the electrode active material coating as an electrode binder. However, on the one hand, the polyurethane resin provided in the disclosure can only use alicyclic isocyanates and / or aromatic isocyanates. On the other hand, the disclosure does not discuss or limit the structure of polyolefin polyols and hydrogenated polyolefin polyols, especially the alkyl side chain content.

[0005] CN114698377A discloses a method for preparing and using a polyolefin-based waterborne polyurethane, characterized by excellent storage stability and excellent adhesion to a variety of substrates. The polyolefin polyol used in the polyolefin polyol comprises a weight ratio of ethylene to an α-olefin having 3 to 8 carbon atoms (ethylene / α-olefin) of 5 / 95 to 65 / 35, and the α-olefin portion (A1) has an isotacticity of 1 to 50%. However, the polymer system of the polyolefin-based waterborne polyurethane disclosed herein contains a large number of cis / trans (Z / E) isomers, which compromise the flexibility of the soft segment. Due to its configuration and steric hindrance, the soft segment struggles to achieve a high level of phase separation. The presence of the α-olefin (1,2-vinyl) also exacerbates this drawback.

[0006] In summary, current conventional water-based polyurethane products contain a large number of highly polar ester bonds, ether bonds, and carbonate bonds, which make the overall polarity of the polymer chain segments relatively high, resulting in poor swelling properties of the polyurethane film, greatly limiting its application in solvent environments. In addition, in existing polyolefin-based water-based polyurethane products, since they mostly use highly rigid hard segments, it is difficult to achieve a balanced strength and elongation at break of the polyurethane film produced.

[0007] Therefore, developing an aqueous polyurethane dispersion with both excellent mechanical properties and solvent resistance is a technical problem that urgently needs to be solved in this field.

[0008] Summary of the Invention

[0009] The following is a summary of the subject matter described in detail herein. This summary is not intended to limit the scope of the claims.

[0010] In view of the deficiencies in the prior art, the purpose of the present application is to provide an aqueous polyurethane dispersion, a preparation method and application thereof. The aqueous polyurethane dispersion selects hydrogenated polybutadiene polyol as the soft segment and limits the mass percentage of hydrogenated 1,2-vinyl units in the hydrogenated polybutadiene polyol to no more than 85%, thereby being able to have both excellent solvent resistance and excellent mechanical properties, having high modulus, breaking strength and breaking elongation, and can be used as automotive interior adhesive, electronic adhesive or battery adhesive.

[0011] To achieve this goal, this application adopts the following technical solutions:

[0012] In a first aspect, the present application provides an aqueous polyurethane dispersion, wherein the raw materials of the aqueous polyurethane dispersion include hydrogenated polybutadiene polyol and polyisocyanate;

[0013] The mass percentage of hydrogenated 1,2-vinyl units in the hydrogenated polybutadiene polyol is not higher than 85%, for example, 80%, 75%, 70%, 65%, 60%, 55%, 50%, 45% or 40%.

[0014] The aqueous polyurethane dispersion provided by the present application can introduce a large number of alkyl chains into the polyurethane molecular chain segment by selecting hydrogenated polybutadiene polyol with a mass percentage of 1,2-vinyl units not higher than 85% as a soft segment and combining it with polyisocyanate, thereby effectively adjusting the polarity of the aqueous polyurethane dispersion, making it have unprecedented low polarity and a more flexible chain structure, thereby enabling it to have excellent solvent resistance as well as high breaking strength, elongation at break and modulus, which is more advantageous in high-stress application scenarios; wherein the structural formula of the hydrogenated polybutadiene polyol is n represents the degree of polymerization of the hydrogenated polybutadiene polyol, and a represents the number of 1,2-vinyl units;

[0015] In addition, although the present application uses hydrogenated polybutadiene polyol with a mass percentage of no more than 85% as the soft segment, since the fatty backbone of hydrogenated polybutadiene polyol is entirely composed of sp 3 Hybridized carbon-carbon single bond composition, sp 3The hybridized carbon-carbon single bond can rotate freely, so during high-speed shearing, the large steric side chain can be caused to rotate to the outside by mechanical energy supply, completing the conformational energy barrier crossing, and ultimately promoting the lowest energy conformation, effectively ensuring the degree of microphase separation of the soft and hard segments, thereby providing better emulsion stability, cohesion and solvent resistance; and precisely because the prepared block polymer contains ultra-low polarity fatty long chains and a large number of alkyl side chains, the overall glass transition temperature (Tg) of the obtained aqueous polyurethane dispersion is very low, and can be controlled between -10 and -80°C through formula adjustment. Therefore, the aqueous polyurethane dispersion provided by the present application also has excellent low-temperature resistance and is easy to activate as an adhesive.

[0016] In one embodiment, the mass percentage of hydrogenated 1,2-vinyl units in the hydrogenated polybutadiene polyol is 65-85%. On the one hand, if the mass percentage of hydrogenated 1,2-vinyl units in the hydrogenated polybutadiene polyol is lower than 65%, it is easy to cause the polymer segments of the prepared aqueous polyurethane dispersion to be too flexible and too soft after film formation, which is not conducive to blocking the internal penetration of organic solvents, thereby reducing the mechanical properties and solvent resistance. On the other hand, if the mass percentage of hydrogenated 1,2-vinyl units in the hydrogenated polybutadiene polyol is higher than 85%, it is easy to cause the polymer segments of the prepared aqueous polyurethane dispersion to have too many side chains, which adhere to each other, thereby increasing the viscosity of the emulsion and having poor processing performance. At the same time, during film formation, the internal morphological cavity is too large due to steric hindrance between the segments, which is not conducive to microphase separation, and also leads to unsatisfactory mechanical properties and solvent resistance.

[0017] In one embodiment, the raw materials of the aqueous polyurethane dispersion include 58 to 77 parts by weight of hydrogenated polybutadiene polyol and 16 to 34 parts by weight of polyisocyanate.

[0018] The content of the polyisocyanate may be 18 parts by weight, 20 parts by weight, 22 parts by weight, 24 parts by weight, 26 parts by weight, 28 parts by weight, 30 parts by weight or 32 parts by weight, and may further be 16 to 28 parts by weight.

[0019] The content of the hydrogenated polybutadiene polyol may be 60 parts by weight, 62 parts by weight, 64 parts by weight, 66 parts by weight, 68 parts by weight, 70 parts by weight, 72 parts by weight, 74 parts by weight or 76 parts by weight, and may further be 60 to 77 parts by weight.

[0020] In one embodiment, the molecular weight of the hydrogenated polybutadiene polyol is 1500 to 3500 g / mol, for example, 1600 g / mol, 1800 g / mol, 2000 g / mol, 2200 g / mol, 2400 g / mol, 2600 g / mol, 2800 g / mol, 3000 g / mol, 3200 g / mol or 3400 g / mol, and can further be 2000 to 3500 g / mol.

[0021] In one embodiment, the polyisocyanate includes any one or a combination of at least two of toluene diisocyanate, diphenylmethane diisocyanate, isophorone diisocyanate, hexamethylene diisocyanate or dicyclohexylmethane diisocyanate.

[0022] In one embodiment, the raw materials of the aqueous polyurethane dispersion further include a hydrophilic chain extender, a neutralizer and water.

[0023] In one embodiment, the content of the hydrophilic chain extender in the raw materials of the aqueous polyurethane dispersion is 3.8 to 4.6 parts by weight, for example, 3.9 parts by weight, 4 parts by weight, 4.1 parts by weight, 4.2 parts by weight, 4.3 parts by weight, 4.4 parts by weight or 4.5 parts by weight, and can further be 4 to 4.5 parts by weight.

[0024] In one embodiment, the hydrophilic chain extender includes any one or a combination of at least two of 3-hydroxypropionic acid, dimethylolpropionic acid, dimethylolbutanoic acid, dimethylolacetic acid, trihydroxysulfonic acid or dihydroxysuccinic acid.

[0025] In one embodiment, the content of the neutralizing agent in the raw materials of the aqueous polyurethane dispersion is 2.8 to 3.3 parts by weight, such as 2.9 parts by weight, 3 parts by weight, 3.1 parts by weight or 3.2 parts by weight, and can further be 2.9 to 3.3 parts by weight.

[0026] In the present application, there is no particular limitation on the type of the neutralizing agent, and conventional neutralizing agents in the art may be selected, including but not limited to any one of triethanolamine, triethylamine, sodium hydroxide or N,N-dimethylethanolamine, or a combination of at least two thereof.

[0027] In one embodiment, the solid content of the aqueous polyurethane dispersion is 10-40%, such as 15%, 20%, 25%, 30%, 35% or 40%, and can further be 15-30%.

[0028] In one embodiment, the raw materials of the aqueous polyurethane dispersion further include a structural chain extender.

[0029] In one embodiment, the content of the structural chain extender in the raw materials of the aqueous polyurethane dispersion is not higher than 4.1 parts by weight, for example, 4 parts by weight, 3.8 parts by weight, 3.6 parts by weight, 3.4 parts by weight, 3.2 parts by weight, 3 parts by weight, 2.8 parts by weight, 2.6 parts by weight, 2.4 parts by weight, 2.2 parts by weight or 2 parts by weight, and can further be 0.1 to 3.2 parts by weight.

[0030] In one embodiment, the structural chain extender comprises a small molecule polyamine.

[0031] In one embodiment, the molecular weight of the small molecule polyamine is 60 to 499 g / mol, for example, 100 g / mol, 150 g / mol, 200 g / mol, 250 g / mol, 300 g / mol, 350 g / mol, 400 g / mol or 450 g / mol.

[0032] In one embodiment, the small molecule polyamine includes any one or a combination of at least two of ethylenediamine, hexamethylenediamine, pentamethylenediamine, diethylenetriamine, isophoronediamine, 4,4'-diphenylmethanediamine or 4,4'-diaminodicyclohexylmethane, and can further be ethylenediamine and / or diethylenetriamine.

[0033] In one embodiment, the raw materials of the aqueous polyurethane dispersion further include a catalyst.

[0034] In one embodiment, the catalyst content in the raw materials of the aqueous polyurethane dispersion is not higher than 1000 ppm, for example, 900 ppm, 800 ppm, 700 ppm, 600 ppm, 500 ppm, 400 ppm, 300 ppm, 200 ppm or 100 ppm.

[0035] In the present application, there is no special limitation on the type of the catalyst. An organic bismuth catalyst or an organic tin catalyst can be selected, and Bi@8108 or dimethyltin dineodecanoate from a leading American company can be selected, and dimethyltin dineodecanoate can be further selected.

[0036] In one embodiment, the raw materials of the aqueous polyurethane dispersion further include an organic solvent, and the amount of the organic solvent used is 1 to 3 times the total amount of other components used, such as 1.5 times, 2 times or 2.5 times.

[0037] In one embodiment, the boiling point of the organic solvent is 40-85°C, such as 45°C, 50°C, 55°C, 60°C, 65°C, 70°C, 75°C or 80°C, including but not limited to acetone and / or butanone.

[0038] In one embodiment, the average particle size of the solid particles in the aqueous polyurethane dispersion is 20 to 500 nm, for example, 50 nm, 100 nm, 150 nm, 200 nm, 250 nm, 300 nm, 350 nm, 400 nm or 450 nm, and can further be 50 to 250 nm.

[0039] In a second aspect, the present application provides a method for preparing the aqueous polyurethane dispersion as described in the first aspect, the preparation method comprising: reacting polyisocyanate and hydrogenated polybutadiene polyol to obtain the aqueous polyurethane dispersion.

[0040] In one embodiment, the preparation method comprises the following steps:

[0041] (1) reacting a polyisocyanate, a hydrogenated polybutadiene polyol, a hydrophilic chain extender, optionally a catalyst, and optionally a portion of an organic solvent to obtain an isocyanate-terminated polyurethane prepolymer;

[0042] (2) reacting the polyurethane prepolymer obtained in step (1), a neutralizing agent and a remaining optional organic solvent, adding water for dispersion, then adding an optional structural chain extender for post-chain extension, and finally removing the organic solvent to obtain the aqueous polyurethane dispersion.

[0043] In one embodiment, the mass ratio of the organic solvent in step (1) to the organic solvent in step (2) is 1:(0.5-2), for example, 1:0.7, 1:0.9, 1:1.1, 1:1.3, 1:1.5, 1:1.7 or 1:1.9, etc.

[0044] In one embodiment, the reaction temperature in step (1) is 75-85°C, for example, 76°C, 77°C, 78°C, 79°C, 80°C, 81°C, 82°C, 83°C or 84°C.

[0045] In one embodiment, the reaction in step (1) ends when the mass percentage of NCO groups in the reaction system reaches the theoretical value.

[0046] It should be noted that the neutralizing agent and the structural chain extender in step (2) are both dissolved in water in advance and added to the reaction in the form of an aqueous solution, and the water is included in the total amount of water in the raw materials.

[0047] In one embodiment, the reaction temperature in step (2) is 35-45°C, such as 37°C, 39°C, 41°C or 43°C.

[0048] In one embodiment, the reaction time of step (2) is 10 to 20 minutes, for example, 12 minutes, 14 minutes, 16 minutes or 18 minutes.

[0049] In one embodiment, the temperature of the post-chain extension in step (2) is 40-55°C, such as 42°C, 44°C, 46°C, 48°C, 50°C, 52°C or 54°C.

[0050] In one embodiment, the post-chain extension time in step (2) is 10 to 20 minutes, such as 12 minutes, 14 minutes, 16 minutes or 18 minutes.

[0051] In one embodiment, the pH value of the emulsion obtained after the post-chain extension in step (2) is greater than 6, such as 7, 8 or 9.

[0052] In one embodiment, the method for removing the organic solvent in step (2) is distillation under reduced pressure.

[0053] In a third aspect, the present application provides a use of the aqueous polyurethane dispersion as described in the first aspect as an automotive interior adhesive, electronic adhesive or battery adhesive.

[0054] Compared with the prior art, this application has the following beneficial effects:

[0055] The raw materials of the aqueous polyurethane dispersion provided in the present application include hydrogenated polybutadiene polyol and polyisocyanate, and the mass percentage of hydrogenated 1,2-vinyl units in the hydrogenated polybutadiene polyol is not higher than 85%; by selecting the hydrogenated polybutadiene polyol as the soft segment and limiting the mass percentage of hydrogenated 1,2-vinyl units in the hydrogenated polybutadiene polyol to not higher than 85%, the obtained aqueous polyurethane dispersion can have both excellent solvent resistance and mechanical properties, has high modulus, breaking strength and elongation at break, and can be used as automotive interior adhesive, electronic adhesive or battery adhesive.

[0056] Still other aspects will become apparent upon reading and understanding the detailed description. DETAILED DESCRIPTION

[0057] The technical solution of the present application is further described below through specific implementation methods. Those skilled in the art should understand that the embodiments are only used to help understand the present application and should not be regarded as specific limitations of the present application.

[0058] Some of the raw material information involved in the specific implementation of this application is as follows:

[0059] Hydrogenated polybutadiene polyol (HLBH-P3000): The mass percentage of hydrogenated 1,2-vinyl units is 65%, Mn=3100 g / mol, ( HLBH-P3000, Crayville);

[0060] Hydrogenated polybutadiene polyol (HLBH-P2000): The mass percentage of hydrogenated 1,2-vinyl units is 65%, Mn=2100 g / mol, ( HLBH-P3000, Crayville);

[0061] Hydrogenated polybutadiene polyol (GI3000): The mass percentage of hydrogenated 1,2-vinyl units is 85%, Mn=3100 g / mol, ( GI3000, Japan Soda);

[0062] Hydrogenated polybutadiene polyol (GI2000): The mass percentage of hydrogenated 1,2-vinyl units is 95%, Mn=2100 g / mol, ( GI2000, Japan Soda);

[0063] The mass percentage of 1,2-vinyl unit of polybutadiene polyol (LBH-P3000) is 65%, Mn=3100g / mol, ( LBH-P3000, Crayville);

[0064] Catalyst: dimethyltin diceneodecanoate, reagent grade, Bidex Pharmaceuticals;

[0065] Dimethylolpropionic acid (DMPA): technical grade, Perstorp Chemical Company;

[0066] Triethylamine: analytical grade, Sinopharm Chemical Reagent Co., Ltd.;

[0067] Butanone: industrial grade, Zibo Qixiang Tengda Chemical Co., Ltd.

[0068] Hexamethylene diisocyanate (HDI): industrial grade, Wanhua Chemical Group Co., Ltd.

[0069] Dicyclohexylmethane diisocyanate (HMDI): industrial grade, Wanhua Chemical Group Co., Ltd.

[0070] Ethylenediamine: analytical grade, Sinopharm Chemical Reagent Co., Ltd.;

[0071] Diethylenetriamine: analytical grade, Sinopharm Chemical Reagent Co., Ltd.;

[0072] Unless otherwise specified, other raw materials are conventional products and can be purchased from the market.

[0073] Example 1

[0074] A waterborne polyurethane dispersion having a solid content of 20% and a solid particle size of about 173 nm;

[0075] The preparation method of the aqueous polyurethane dispersion provided in this embodiment comprises the following steps:

[0076] (1) 190 g of dehydrated HLBH-P3000, 40 g of HMDI, 11 g of DMPA, 320 g of butanone, and 0.144 g of dimethyltin dineodecanoate were added to a 1 L four-necked round-bottom flask equipped with a nitrogen inlet and outlet, and the mixture was stirred and reacted at 75° C. until the mass percentage of NCO groups in the mixture reached 0.18%, thereby obtaining a polyurethane prepolymer;

[0077] (2) The polyurethane prepolymer obtained in step (1) was cooled to 50° C., dissolved in 160 g of butanone, and cooled again to 35° C., 15.3 g of triethylamine aqueous solution (8.3 g of triethylamine dissolved in 7 g of water) was added, stirred and reacted for 20 min, and then 981 g of water was added for dispersion. The temperature was raised to 40° C., and 10.5 g of diethylenetriamine aqueous solution (0.5 g of diethylenetriamine dissolved in 10 g of water) was added, stirred and chain extended for 20 min to obtain a crude emulsion with a pH value of 7.4. Finally, the crude emulsion was subjected to reduced pressure distillation to separate the butanone, thereby obtaining the aqueous polyurethane dispersion.

[0078] Example 2

[0079] A waterborne polyurethane dispersion having a solid content of 15% and a solid particle size of about 232 nm;

[0080] The preparation method of the aqueous polyurethane dispersion provided in this embodiment comprises the following steps:

[0081] (1) 250 g of dehydrated HLBH-P3000, 40 g of HMDI, 16.5 g of HDI, 14 g of DMPA, and 456 g of butanone were added to a 2 L four-necked round-bottom flask equipped with a nitrogen inlet and outlet, and stirred at 75° C. until the mass percentage of the NCO group in the mixture reached 0.74%, thereby obtaining a polyurethane prepolymer;

[0082] (2) The polyurethane prepolymer obtained in step (1) was cooled to 50° C., dissolved in 456 g of butanone, and cooled again to 45° C., 27.55 g of triethylamine aqueous solution (10.55 g of triethylamine dissolved in 17 g of water) was added, stirred for reaction for 10 min, and then 1756 g of water was added for dispersion. The temperature was raised to 45° C., and 22 g of ethylenediamine aqueous solution (2.0 g of ethylenediamine dissolved in 20 g of water) was added, stirred, and chain extended for 15 min to obtain a crude emulsion with a pH value of 7.4. Finally, the crude emulsion was subjected to reduced pressure distillation to separate the butanone, thereby obtaining the aqueous polyurethane dispersion.

[0083] Example 3

[0084] A waterborne polyurethane dispersion having a solid content of 25% and a solid particle size of about 248 nm;

[0085] The preparation method of the aqueous polyurethane dispersion provided in this embodiment comprises the following steps:

[0086] (1) 123 g of dehydrated HLBH-P3000, 60 g of HMDI, 8.1 g of DMPA, 63.7 g of butanone, and 0.19 g of dimethyltin dineodecanoate were added to a 1 L four-necked round-bottom flask equipped with a nitrogen inlet and outlet, and the mixture was stirred and reacted at 85° C. until the mass percentage of NCO groups in the mixture reached 3.8%, thereby obtaining a polyurethane prepolymer;

[0087] (2) The polyurethane prepolymer obtained in step (1) was cooled to 60° C., dissolved in 127.4 g of butanone, and cooled again to 35° C., 23.1 g of triethylamine aqueous solution (6.4 g of triethylamine dissolved in 17 g of water) was added, stirred for reaction for 15 minutes, and then 573.3 g of water was added for dispersion. The temperature was raised to 50° C., and 20.5 g of diethylenetriamine aqueous solution (0.5 g of diethylenetriamine dissolved in 20 g of water) was added, stirred, and chain extended for 15 minutes to obtain a crude emulsion with a pH value of 7.4. Finally, the crude emulsion was subjected to reduced pressure distillation to separate the butanone, thereby obtaining the aqueous polyurethane dispersion.

[0088] Example 4

[0089] A waterborne polyurethane dispersion having a solid content of 30% and a solid particle size of about 229 nm;

[0090] The preparation method of the aqueous polyurethane dispersion provided in this embodiment comprises the following steps:

[0091] (1) 168 g of dehydrated GI3000, 47 g of HMDI, 10.5 g of DMPA, 225.5 g of butanone, and 0.133 g of dimethyltin dineodecanoate were added to a 1 L four-necked round-bottom flask equipped with a nitrogen inlet and outlet, and the mixture was stirred and reacted at 75° C. until the mass percentage of NCO groups in the mixture reached 0.89%, thereby obtaining a polyurethane prepolymer;

[0092] (2) The polyurethane prepolymer obtained in step (1) was cooled to 50° C., dissolved in 225.5 g of butanone, and cooled again to 35° C., 26.5 g of triethylamine aqueous solution (7.5 g of triethylamine dissolved in 19 g of water) was added, stirred and reacted for 15 minutes, and then 505.3 g of water was added for dispersion. The temperature was raised to 45° C., and 20.3 g of diethylenetriamine aqueous solution (0.3 g of diethylenetriamine dissolved in 20 g of water) was added, stirred and chain extended for 10 minutes to obtain a crude emulsion with a pH value of 7.4. Finally, the crude emulsion was subjected to reduced pressure distillation to separate the butanone, thereby obtaining the aqueous polyurethane dispersion.

[0093] Example 5

[0094] A waterborne polyurethane dispersion having a solid content of 25% and solid particles having a particle size of about 160 nm;

[0095] The preparation method of the aqueous polyurethane dispersion provided in this embodiment comprises the following steps:

[0096] (1) 192.5 g of dehydrated HLBH-P3000, 46 g of HMDI, 11.5 g of DMPA, 250 g of butanone, and 0.15 g of dimethyltin dineodecanoate were added to a 1 L four-necked round-bottom flask equipped with a nitrogen inlet and outlet, and the mixture was stirred and reacted at 75° C. until the mass percentage of the NCO group in the mixture reached 0.48%, thereby obtaining a polyurethane prepolymer;

[0097] (2) The polyurethane prepolymer obtained in step (1) was cooled to 50° C., dissolved in 250 g of butanone, and cooled again to 35° C., 17.66 g of triethylamine aqueous solution (8.66 g of triethylamine dissolved in 9 g of water) was added, stirred and reacted for 15 minutes, and then 750 g of water was added for dispersion. The temperature was raised to 45° C., and 21.2 g of diethylenetriamine aqueous solution (1.2 g of diethylenetriamine dissolved in 20 g of water) was added, stirred and chain extended for 15 minutes to obtain a crude emulsion with a pH value of 7.4. Finally, the crude emulsion was subjected to reduced pressure distillation to separate the butanone, thereby obtaining the aqueous polyurethane dispersion.

[0098] Example 6

[0099] A waterborne polyurethane dispersion having a solid content of 25% and a solid particle size of about 61 nm;

[0100] The preparation method of the aqueous polyurethane dispersion provided in this embodiment comprises the following steps:

[0101] (1) 184 g of dehydrated HLBH-P2000, 54.5 g of HMDI, 11.5 g of DMPA, 250 g of butanone, and 0.2 g of dimethyltin dineodecanoate were added to a 1 L four-necked round-bottom flask equipped with a nitrogen inlet and outlet, and the mixture was stirred and reacted at 75° C. until the mass percentage of NCO groups in the mixture reached 0.67%, thereby obtaining a polyurethane prepolymer;

[0102] (2) The polyurethane prepolymer obtained in step (1) was cooled to 50° C., dissolved in 250 g of butanone, and cooled again to 35° C., 17.66 g of triethylamine aqueous solution (8.66 g of triethylamine dissolved in 9 g of water) was added, stirred and reacted for 15 minutes, and then 750 g of water was added for dispersion. The temperature was raised to 45° C., and 21.95 g of diethylenetriamine aqueous solution (1.95 g of diethylenetriamine dissolved in 20 g of water) was added, stirred and chain extended for 15 minutes to obtain a crude emulsion with a pH value of 7.3. Finally, the crude emulsion was subjected to reduced pressure distillation to separate the butanone, thereby obtaining the aqueous polyurethane dispersion.

[0103] Example 7

[0104] A waterborne polyurethane dispersion having a solid content of 25% and a solid particle size of about 131 nm;

[0105] The preparation method of the aqueous polyurethane dispersion provided in this embodiment comprises the following steps:

[0106] (1) 190 g of dehydrated HLBH-P3000, 95 g of HMDI, 11 g of DMPA, 256 g of butanone, and 0.15 g of dimethyltin dineodecanoate were added to a 1 L four-necked round-bottom flask equipped with a nitrogen inlet and outlet, and the mixture was stirred and reacted at 75° C. until the mass percentage of the NCO group in the mixture reached 0.18%, thereby obtaining a polyurethane prepolymer;

[0107] (2) The polyurethane prepolymer obtained in step (1) was cooled to 50° C., dissolved in 256 g of butanone, and cooled again to 35° C., 37.3 g of triethylamine aqueous solution (8.3 g of triethylamine dissolved in 29 g of water) was added, stirred and reacted for 15 minutes, and then 768 g of water was added for dispersion. The temperature was raised to 45° C., and 55 g of diethylenetriamine aqueous solution (15 g of diethylenetriamine dissolved in 40 g of water) was added, stirred and chain extended for 15 minutes to obtain a crude emulsion with a pH value of 7.4. Finally, the crude emulsion was subjected to reduced pressure distillation to separate the butanone, thereby obtaining the aqueous polyurethane dispersion.

[0108] Example 8

[0109] A waterborne polyurethane dispersion having a solid content of 25% and a solid particle size of about 244 nm;

[0110] The preparation method of the aqueous polyurethane dispersion provided in this embodiment comprises the following steps:

[0111] (1) 250 g of dehydrated HLBH-P3000, 46 g of HMDI, 11 g of DMPA, 307.5 g of butanone, and 0.18 g of dimethyltin dineodecanoate were added to a 1 L four-necked round-bottom flask equipped with a nitrogen inlet and outlet, and the mixture was stirred and reacted at 75° C. until the mass percentage of the NCO group in the mixture reached 0.15%, thereby obtaining a polyurethane prepolymer;

[0112] (2) The polyurethane prepolymer obtained in step (1) was cooled to 50° C., dissolved in 307.5 g of butanone, and cooled again to 35° C., 15.66 g of triethylamine aqueous solution (8.66 g of triethylamine dissolved in 7 g of water) was added, stirred and reacted for 15 minutes, and then 922 g of water was added for dispersion. The temperature was raised to 45° C., and 20.3 g of diethylenetriamine aqueous solution (0.3 g of diethylenetriamine dissolved in 20 g of water) was added, stirred and chain extended for 15 minutes to obtain a crude emulsion with a pH value of 7.5. Finally, the crude emulsion was subjected to reduced pressure distillation to separate the butanone, thereby obtaining the aqueous polyurethane dispersion.

[0113] Comparative Example 1

[0114] A waterborne polyurethane dispersion is prepared, which differs from Example 1 only in that LBH-P3000 is used in an equal molar amount to replace HLBH-P3000, and other substances, amounts used, and preparation methods are the same as those in Example 1.

[0115] Comparative Example 2

[0116] A waterborne polyurethane dispersion is prepared, which differs from Example 1 only in that GI2000 is used in an equal molar amount to replace HLBH-P3000, and other substances, amounts used, and preparation methods are the same as those in Example 1.

[0117] Performance testing:

[0118] (1) Solid content: Take an appropriate amount of waterborne polyurethane dispersion and place it in a container made of tin foil. Weigh the weight before and after placing it at 150°C for 20 minutes to calculate its solid content.

[0119] (2) Particle size: tested using a Malvern particle size analyzer;

[0120] (3) 100% modulus, breaking strength, and elongation at break: The aqueous polyurethane dispersion was spread onto a polytetrafluoroethylene film-forming mold to obtain a polyurethane film with a thickness of 0.5 mm. The polyurethane film was then cut into dumbbell shapes as test specimens. Finally, the polyurethane test specimens were tested using a Tesla machine, MTS Model E43, at a pulling speed of 10 mm / min.

[0121] (4) Solvent resistance: The aqueous polyurethane dispersion was spread into a polytetrafluoroethylene film-forming mold to obtain a film with a thickness of 0.5 mm and a length of 2 cm. 2 and a width of 2cm 2 The polyurethane film was prepared and the original mass of the polyurethane film was recorded. Then, in a glove box, the polyurethane film was immersed in an electrolyte (the solvent was diethyl carbonate, ethylene carbonate, and propylene carbonate in a volume ratio of 1:1:1, and the lithium salt was 1M LiPF6) and sealed. The film was placed in an oven at 50°C for 2 days. The polyurethane film was taken out and the surface was wiped dry with absorbent paper. After recording the mass, the percentage of mass increase was calculated.

[0122] The aqueous polyurethane dispersions provided in Examples 1 to 8 and Comparative Examples 1 to 2 were tested according to the above test method. The test results are shown in Table 1:

[0123] Table 1

[0124] According to the data in Table 1, it can be seen that the waterborne polyurethane dispersion provided by the present application can have both excellent solvent resistance and mechanical properties;

[0125] Specifically, the polyurethane films prepared from the aqueous polyurethane dispersions provided in Examples 1 to 6 had a 100% modulus of 1.2 to 4.9%, a breaking strength of 2.0 to 8.6 MPa, and an elongation at break of 194 to 627%. Solvent resistance tests showed that the percentage increase in mass before and after immersion in the electrolyte was 17 to 34%.

[0126] Compared with Examples 1 to 6, since the soft segment of the aqueous polyurethane dispersion provided in Comparative Example 1 is polybutadiene polyol, the mechanical properties and solvent resistance of the prepared polyurethane film are poor;

[0127] Compared with Examples 1 to 6, since the mass percentage of hydrogenated 1,2-vinyl units in the soft segment of the aqueous polyurethane dispersion provided in Comparative Example 2 is too high, the mechanical properties and solvent resistance of the polyurethane film after being made are also deteriorated;

[0128] Furthermore, by comparing the data of Examples 1, 7, and 8, it can be seen that if the amount of polyisocyanate added to the raw materials of the aqueous polyurethane dispersion is relatively too high (Example 7), the hardness after film formation will be too high, the elongation at break will be only 76% (it cannot be stretched to 100%, so there is no 100% modulus data), and the solvent resistance will be poor; and if the amount of hydrogenated polybutadiene polyol added to the raw materials of the aqueous polyurethane dispersion is relatively too high (Example 8), the tensile strength of the film will be low; neither of them can have both excellent mechanical properties and solvent resistance.

[0129] The applicant declares that this application uses the above-mentioned embodiments to illustrate a waterborne polyurethane dispersion, its preparation method, and its application. However, this application is not limited to the above-mentioned embodiments, which does not mean that this application must rely on the above-mentioned embodiments in order to be implemented. Those skilled in the art should understand that any improvements to this application, equivalent replacements for various raw materials in the product of this application, the addition of auxiliary ingredients, and the selection of specific methods, etc., fall within the scope of protection and disclosure of this application.

Claims

1. An aqueous polyurethane dispersion, the raw materials of which include hydrogenated polybutadiene polyol and polyisocyanate; The mass percentage content of hydrogenated 1,2-vinyl units in the hydrogenated polybutadiene polyol is not higher than 85%.

2. The aqueous polyurethane dispersion according to claim 1, wherein The mass percentage content of hydrogenated 1,2-vinyl units in the hydrogenated polybutadiene polyol is 65 - 85%.

3. The aqueous polyurethane dispersion according to claim 1 or 2, wherein, The raw materials of the aqueous polyurethane dispersion include 58 - 77 parts by weight of hydrogenated polybutadiene polyol and 16 - 34 parts by weight of polyisocyanate according to parts by weight; Optionally, the content of hydrogenated polybutadiene polyol in the raw materials of the aqueous polyurethane dispersion is 60 - 77 parts by weight; Optionally, the molecular weight of the hydrogenated polybutadiene polyol is 1500 - 3500 g / mol, and further optionally 2000 - 3500 g / mol; Optionally, the content of polyisocyanate in the raw materials of the aqueous polyurethane dispersion is 16 - 28 parts by weight; Optionally, the polyisocyanate includes any one or a combination of at least two of toluene diisocyanate, diphenylmethane diisocyanate, isophorone diisocyanate, hexamethylene diisocyanate or dicyclohexylmethane diisocyanate.

4. The aqueous polyurethane dispersion according to any one of claims 1 to 3, wherein, The raw materials of the aqueous polyurethane dispersion further include a hydrophilic chain extender, a neutralizer and water; Optionally, the content of the hydrophilic chain extender in the raw materials of the aqueous polyurethane dispersion is 3.8 - 4.6 parts by weight; Optionally, the hydrophilic chain extender includes any one or a combination of at least two of 3-hydroxypropionic acid, dimethylolpropionic acid, dimethylolbutyric acid, dimethylolacetic acid, trihydroxy sulfonic acid or dihydroxy succinic acid; Optionally, the content of the neutralizer in the raw materials of the aqueous polyurethane dispersion is 2.8 - 3.3 parts by weight; Optionally, the solid content of the aqueous polyurethane dispersion is 10 - 40%, and further optionally 15 - 30%.

5. The aqueous polyurethane dispersion according to claim 4, wherein The raw materials of the aqueous polyurethane dispersion further include a structural chain extender; Optionally, the content of the structural chain extender in the raw materials of the aqueous polyurethane dispersion is not higher than 4.1 parts by weight; Optionally, the structural chain extender includes small molecule polyamines; Optionally, the molecular weight of the small molecule polyamines is 60 - 499 g / mol; Optionally, the small molecule polyamines include any one or a combination of at least two of ethylenediamine, hexamethylenediamine, pentamethylenediamine, diethylenetriamine, isophoronediamine, 4,4'-diphenylmethanediamine or 4,4'-diaminodicyclohexylmethane; Optionally, the raw materials of the aqueous polyurethane dispersion further include a catalyst; Optionally, the content of the catalyst in the raw materials of the aqueous polyurethane dispersion is not higher than 1000 ppm; Optionally, the raw materials of the aqueous polyurethane dispersion further include an organic solvent.

6. The aqueous polyurethane dispersion according to any one of claims 1 to 5, wherein, The particle size of the solid particles in the aqueous polyurethane dispersion is 20 - 500 nm, and further optionally 50 - 250 nm.

7. A method for preparing an aqueous polyurethane dispersion according to any one of claims 1 to 6, comprising: React the polyisocyanate and the hydrogenated polybutadiene polyol to obtain the aqueous polyurethane dispersion.

8. The preparation method according to claim 7, wherein The preparation method specifically includes the following steps: (1) React a polyisocyanate, a hydrogenated polybutadiene polyol, a hydrophilic chain extender, optionally a catalyst and optionally a partial organic solvent to obtain an isocyanate-terminated polyurethane prepolymer; (2) React the polyurethane prepolymer obtained in step (1), a neutralizing agent and the remaining optional organic solvent, add water for dispersion, then add an optional structural chain extender for post-chain extension, and finally remove the organic solvent to obtain the aqueous polyurethane dispersion.

9. The preparation method according to claim 8, characterized in that, The temperature of the reaction in step (1) is 75 - 85 °C; Optionally, the reaction in step (1) ends when the mass percentage content of NCO groups in the reaction system reaches the theoretical value; Optionally, the temperature of the reaction in step (2) is 35 - 45 °C; Optionally, the reaction time in step (2) is 10 - 20 min; Optionally, the temperature of the post-chain extension in step (2) is 40 - 55 °C; Optionally, the time of the post-chain extension in step (2) is 10 - 20 min.

10. Use of an aqueous polyurethane dispersion according to any one of claims 1 - 6 as an automotive interior adhesive, an electronic adhesive or a battery adhesive.

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