An aqueous polyurethane resin, its preparation method and application

Abstract

The present invention provides an aqueous polyurethane resin, a preparation method thereof and an application. The raw materials for preparing the aqueous polyurethane resin include a combination of a diisocyanate, a polyester polyol, a hydroxyl-terminated polysiloxane, a hydrophilic chain extender small molecule diol and a stabilizer, and the stabilizer includes a polyether ester polyol. By selecting the hydroxyl-terminated polysiloxane and the polyester polyol to be combined and reacted with the diisocyanate, the present invention successfully introduces a siloxane structure into the polyurethane molecular chain segment, improves the water resistance of the polyurethane resin, and at the same time adds a polyether ester polyol as a stabilizer, effectively improving the compatibility of the hydroxyl-terminated polysiloxane and the polyester polyol, enabling the two to be uniformly dispersed and maintaining the same reaction activity, and finally obtaining an aqueous polyurethane resin with high stability and low water absorption.

Description

Technical Field

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

[0002] With the restrictions on organic solvents, aqueous polyurethane resins have gradually replaced solvent-based polyurethane resins. Aqueous polyurethane resins have the advantages of being non-toxic, pollution-free, easy to store and convenient to use. Aqueous polyurethane resins include polyether-based aqueous polyurethane resins and polyester-based aqueous polyurethane resins. Among them, polyester-based aqueous polyurethane resins have the advantages of low pollution, non-flammability and convenient sources, and are widely used in automotive interiors, house decoration, fabric finishing and other aspects. However, due to the poor hydrolysis resistance and unsatisfactory mechanical properties of polyester-based aqueous polyurethanes, their applications in some fields are restricted.

[0003] At present, to solve the above problems, hydroxyl-terminated polysiloxane is usually used to modify waterborne polyurethane resin. CN106519169A discloses a waterborne organosilicon polyurethane dispersion and its preparation and application. This waterborne organosilicon polyurethane dispersion has excellent low-temperature flexibility, anti-blocking, and high-temperature resistance properties. And it has very excellent waterproof and anti-staining properties. The obtained waterborne organosilicon polyurethane dispersion of this invention is very suitable for use as a surface coating protective coating and can be used for the protection and treatment of coatings, leather, paper, glass, etc. CN102633971A discloses a continuous production process for waterborne polyurethane dispersion based on the design of a twin-screw reactor. After the raw materials for synthesizing waterborne polyurethane are mixed, they are injected into the twin-screw reactor and polymerized at 120-200°C for 3-15 minutes in the twin-screw reactor. The polymerized polyurethane prepolymer is extruded from the twin-screw reactor and enters two series-connected pressure mixers, where it is mixed with water at 90-150°C. The mixer can use mechanical dispersion or ultrasonic dispersion. The reactants are cooled and depressurized to obtain the waterborne polyurethane dispersion. In the process provided by this invention, no solvent or a small amount of organic solvent can be used, and the production cycle is very short. It only takes 3-15 minutes from the raw materials entering the continuous production device to obtaining the product, and the process is fully automated. CN105440240A discloses a continuous production method for preparing waterborne polyurethane ionomers and their dispersions, including the following steps: (1) Polymer diol, diisocyanate, diol, and catalyst are respectively input into a mixing head and then input into twin-screw reactor A for reaction extrusion to obtain an isocyanate-terminated prepolymer; (2) The isocyanate-terminated prepolymer and an amino-sulfonate hydrophilic chain extender are injected into twin-screw reactor B for reaction extrusion and granulation to obtain waterborne polyurethane ionomers; (3) After the polyurethane particles are dissolved in a solvent, dispersed in water, and the solvent is removed, a waterborne polyurethane ionomer dispersion can be obtained. This invention improves the molecular weight and cohesive energy of the waterborne polyurethane dispersion, improves the storage stability and long-term effectiveness after construction of the dispersion; greatly reduces the addition amount of sulfonate groups in the dispersion, and improves the performance and stability while reducing the cost of the dispersion.

[0004] However, there are problems with poor compatibility between polyester polyol and hydroxyl-terminated polysiloxane and non-uniform reaction activity in the hydroxyl-terminated polysiloxane-modified waterborne polyurethane resin, which will further lead to poor hydrolysis resistance of the finally obtained waterborne polyurethane resin.

[0005] Therefore, to solve the above technical problems, how to improve the compatibility between polyester polyol and hydroxyl-terminated polysiloxane and finally obtain a waterborne polyurethane resin with low water absorption and high stability has become a technical problem urgently to be solved in this field. Summary of the Invention

[0006] Aiming at the deficiencies of the prior art, the purpose of the present invention is to provide an aqueous polyurethane resin, a preparation method and an application thereof. By introducing polyether ester polyol as a stabilizer into the preparation raw materials, the compatibility of polyester polyol and hydroxy polysiloxane is improved, so that the above two can be uniformly mixed and the intermediate reaction activity is kept consistent. Furthermore, after reacting with diisocyanate, an aqueous polyurethane resin with high stability and low water absorption can be obtained.

[0007] To achieve this purpose, the present invention adopts the following technical solutions:

[0008] In the first aspect, the present invention provides an aqueous polyurethane resin. The preparation raw materials of the aqueous polyurethane resin include the following components by weight:

[0009]

[0010] The stabilizer includes polyether ester polyol.

[0011] Among them, the diisocyanate can be 12 parts by weight, 14 parts by weight, 16 parts by weight, 18 parts by weight, 20 parts by weight, 22 parts by weight, 24 parts by weight, 26 parts by weight or 28 parts by weight, etc.

[0012] The polyester polyol can be 25 parts by weight, 30 parts by weight, 35 parts by weight, 40 parts by weight, 45 parts by weight, 50 parts by weight, 55 parts by weight, 60 parts by weight or 65 parts by weight, etc.

[0013] The hydroxy polysiloxane can be 3 parts by weight, 4 parts by weight, 5 parts by weight, 6 parts by weight, 7 parts by weight, 8 parts by weight, 9 parts by weight, 10 parts by weight, 11 parts by weight, 12 parts by weight, 13 parts by weight, 14 parts by weight or 15 parts by weight, etc.

[0014] The hydrophilic chain extender can be 1.5 parts by weight, 2 parts by weight, 2.5 parts by weight, 3 parts by weight, 3.5 parts by weight, 4 parts by weight or 4.5 parts by weight, etc.

[0015] The small molecule diol can be 1.5 parts by weight, 2 parts by weight, 2.5 parts by weight, 3 parts by weight, 3.5 parts by weight, 4 parts by weight or 4.5 parts by weight, etc.

[0016] The stabilizer can be 1.5 parts by weight, 2 parts by weight, 2.5 parts by weight, 3 parts by weight, 3.5 parts by weight, 4 parts by weight or 4.5 parts by weight, etc.

[0017] The raw materials for preparing the aqueous polyurethane resin provided by the present invention include a combination of specific amounts of diisocyanate, polyester polyol, hydroxyl polysiloxane, hydrophilic chain extender, small molecule diol and stabilizer, and it is defined that the stabilizer includes polyether ester polyol; the present invention selects hydroxyl polysiloxane and polyester polyol for matching, successfully introduces a polysiloxane structure on the polyurethane molecular chain, and at the same time adds a specific amount of polyether ester polyol as a stabilizer, effectively improving the compatibility of the hydroxyl polysiloxane and polyester polyol, enabling the two to be uniformly mixed and maintaining the same intermediate reaction activity. Finally, an aqueous polyurethane resin with high stability, low water absorption and relatively high surface tension is obtained, so that the emulsion prepared by using the aqueous polyurethane resin also has the advantage of high stability, and also has excellent hydrolysis resistance and stability, and also has the comprehensive performance of preventing hand sweat and anti-sticking.

[0018] Preferably, the diisocyanate includes any one or a combination of at least two of 4,4-diphenylmethane diisocyanate, toluene diisocyanate, p-phenylene diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate or hydrogenated 4,4-diphenylmethane diisocyanate, and more preferably 4,4-diphenylmethane diisocyanate.

[0019] Preferably, the molecular weight of the polyester polyol is 500 - 4000 g / mol, such as 1000 g / mol, 1500 g / mol, 2000 g / mol, 2500 g / mol, 3000 g / mol or 3500 g / mol, etc.

[0020] Preferably, the polyester polyol includes any one or a combination of at least two of polycarbonate diol, polycaprolactone diol, neopentyl glycol adipate diol, hexanediol adipate diol or butanediol adipate diol.

[0021] Preferably, the molecular weight of the hydroxyl polysiloxane is 500 - 3000 g / mol, such as 700 g / mol, 900 g / mol, 1100 g / mol, 1300 g / mol, 1500 g / mol, 1700 g / mol, 1900 g / mol, 2100 g / mol, 2300 g / mol, 2500 g / mol, 2700 g / mol or 2900 g / mol, etc.

[0022] Preferably, the hydroxyl polysiloxane has the structure shown in the following formula Ⅰ:

[0023]

[0024] Among them, R1 and R2 are each independently selected from any one of C1-C20 hydrocarbon groups (such as C2, C4, C6, C8, C10, C12, C14, C16 or C18 hydrocarbon groups, etc.), R3 is selected from any one of C1-C20 (such as C2, C4, C6, C8, C10, C12, C14, C16 or C18 alkyl groups, etc.) alkyl groups, and n is any integer from 5 to 50 (such as 10, 15, 20, 25, 30, 35, 40 or 45, etc.).

[0025] Preferably, the hydrophilic chain extender includes a hydroxy compound containing a hydrophilic group.

[0026] Preferably, the hydroxy compound includes any one or a combination of at least two of dimethylolbutyric acid, dimethylolpropionic acid, glycerol monosuccinate, glycerol monomaleate, trihydroxypropane monosuccinate, trihydroxypropane monomaleate, methyldiethanolamine, a diol containing a sodium sulfonate group, a polyether diol containing a carboxyl group or a polyester diol containing a carboxyl group, and more preferably dimethylolpropionic acid.

[0027] Preferably, the small molecule diol is selected from any one or a combination of at least two of ethylene glycol, 1,3-propanediol, 1,4-butanediol, methylpropanediol, neopentyl glycol, 1,6-hexanediol, 3-methyl-1,5-pentanediol, 1,4-bis(β-hydroxyethoxy)benzene, 1,4-cyclohexanediol, bis(β-hydroxyethyl) terephthalate or benzenedimethanol.

[0028] Preferably, the molecular weight of the polyether ester polyol is 800-2000 g / mol, such as 1000 g / mol, 1100 g / mol, 1200 g / mol, 1300 g / mol, 1400 g / mol, 1500 g / mol, 1600 g / mol, 1700 g / mol, 1800 g / mol or 1900 g / mol, etc.

[0029] In the present invention, the added polyether ester polyol can be a commercially available product or a product prepared according to the prior art.

[0030] Exemplarily, the preparation method of the polyether ester polyol includes: adding adipic acid, 1,4-butanediol and a small molecule polyether polyol into a reaction flask, heating up, and protecting with nitrogen, with the nitrogen inlet placed above the liquid level. When the temperature at the top of the distillation column is about 100 °C, dehydration starts; the temperature is raised to 220 °C, and the temperature at the top of the distillation column is controlled at 100 °C. Then, tetra-isopropyl titanate catalyst is added. After reacting for a period of time, the hydroxyl value and acid value are tested. When the acid value < 1 mg KOH / g, the reaction starts to cool down. The temperature is cooled down to 110 °C, and the nitrogen is turned off, and the reaction ends to obtain the polyether ester polyol.

[0031] Preferably, the molecular weight of the aqueous polyurethane is 50,000 to 80,000 g / mol, such as 53,000 g / mol, 56,000 g / mol, 59,000 g / mol, 62,000 g / mol, 65,000 g / mol, 68,000 g / mol, 71,000 g / mol, 74,000 g / mol or 77,000 g / mol, etc.

[0032] Preferably, the molecular weight distribution of the aqueous polyurethane resin is 1.5 to 2, such as 1.55, 1.6, 1.65, 1.7, 1.75, 1.8, 1.85, 1.9 or 1.95, etc.

[0033] Preferably, other auxiliaries are also included in the raw materials for preparing the aqueous polyurethane resin.

[0034] Preferably, the content of other auxiliaries in the raw materials for preparing the aqueous polyurethane resin is 0 to 5 parts by weight and not equal to 0, such as 0.5 part by weight, 1 part by weight, 1.5 parts by weight, 2 parts by weight, 2.5 parts by weight, 3 parts by weight, 3.5 parts by weight, 4 parts by weight or 4.5 parts by weight, etc.

[0035] Preferably, the other auxiliaries include any one or a combination of at least two of a main antioxidant, a secondary antioxidant, a catalyst or a lubricant.

[0036] In a second aspect, the present invention provides a method for preparing the aqueous polyurethane resin as described in the first aspect, and the preparation method includes the following steps:

[0037] (1) Mix the polyester polyol and the hydroxy polysiloxane, add a stabilizer and optionally other auxiliaries for mixing to obtain a mixture; mix the small molecule diol and the hydrophilic chain extender to obtain a mixture B;

[0038] (2) React the mixture A, the mixture B and the diisocyanate obtained in step (1) to obtain the aqueous polyurethane resin.

[0039] Preferably, the mixing temperature for mixing the polyester polyol and the hydroxy polysiloxane in step (1) is 80 to 100 °C, such as 82 °C, 84 °C, 86 °C, 88 °C, 90 °C, 92 °C, 94 °C, 96 °C or 98 °C, etc.

[0040] Preferably, the mixing temperature for adding the stabilizer and optionally other auxiliaries for mixing in step (1) is 80 to 140 °C, such as 85 °C, 90 °C, 95 °C, 100 °C, 105 °C, 110 °C, 115 °C, 120 °C, 125 °C, 130 °C or 135 °C, etc.

[0041] Preferably, the mixing mass ratio of the small molecule diol A and the hydrophilic chain extender in step (1) is (1-2):1, such as 1.1:1, 1.2:1, 1.3:1, 1.4:1, 1.5:1, 1.6:1, 1.7:1, 1.8:1 or 1.9:1, etc., and more preferably (1.3-1.4):1.

[0042] Preferably, the reaction time in step (2) is 1-3 min, such as 1.2 min, 1.4 min, 1.6 min, 1.8 min, 2 min, 2.2 min, 2.4 min, 2.6 min or 2.8 min, etc.

[0043] Preferably, both the reaction and the mixing in step (2) are carried out in a twin-screw extruder.

[0044] Preferably, the length-diameter ratio of the screws of the twin-screw extruder is 33-64, such as 35, 40, 45, 50 or 55, etc., and more preferably 48-60.

[0045] Preferably, the temperature of the twin-screw extruder is 100-200 °C, such as 110 °C, 120 °C, 130 °C, 140 °C, 150 °C, 160 °C, 170 °C, 180 °C or 190 °C, etc.

[0046] Preferably, the rotation speed of the twin-screw extruder is 150-250 rpm, such as 160 rpm, 170 rpm, 180 rpm, 190 rpm, 200 rpm, 210 rpm, 220 rpm, 230 rpm or 240 rpm, etc.

[0047] Preferably, after the reaction in step (2), it further includes the steps of extrusion, underwater pelletizing and drying.

[0048] Preferably, the water temperature for underwater pelletizing is 0-30 °C, such as 2 °C, 4 °C, 6 °C, 8 °C, 10 °C, 12 °C, 14 °C, 16 °C, 18 °C, 20 °C, 22 °C, 24 °C, 26 °C or 28 °C, etc.

[0049] Preferably, the drying time is 4-8 h, such as 4.5 h, 5 h, 5.5 h, 6 h, 6.5 h, 7 h or 7.5 h, etc.

[0050] As a preferred technical solution of the present invention, the preparation method includes the following steps:

[0051] (1) Mix the polyester polyol and the hydroxy polysiloxane at 80-100 °C, add the stabilizer and optionally other additives and mix at 80-140 °C to obtain a mixture; mix the small molecule diol and the hydrophilic chain extender to obtain a mixture B;

[0052] (2) React the mixture A, mixture B and diisocyanate obtained in step (1) in a twin-screw extruder for 1 to 3 minutes. The length-diameter ratio of the screws of the twin-screw extruder is 33 to 64, the temperature is 100 to 200 °C, the rotation speed is 150 to 250 rpm, and optionally other additives are added for mixing, followed by extrusion, underwater pelletization and drying to obtain the aqueous polyurethane resin.

[0053] In a third aspect, the present invention provides an application of the aqueous polyurethane resin as described in the first aspect in automotive interiors, house decoration or fabric finishing.

[0054] Compared with the prior art, the present invention has the following beneficial effects:

[0055] (1) The raw materials for preparing the aqueous polyurethane resin provided by the present invention include a combination of specific amounts of diisocyanate, polyester polyol, hydroxyl polysiloxane, hydrophilic chain extender, small molecule diol and stabilizer, and the stabilizer includes polyether ester polyol; by selecting hydroxyl polysiloxane and polyester polyol for combination, a polysiloxane structure is successfully introduced into the polyurethane molecular chain, and at the same time, a specific amount of polyether ester polyol is added as a stabilizer, effectively improving the compatibility of the hydroxyl polysiloxane and polyester polyol, enabling the two to be uniformly mixed and maintaining the same intermediate reaction activity, and finally obtaining an aqueous polyurethane resin with high stability and low water absorption;

[0056] (2) The present invention also provides a preparation method of an aqueous polyurethane resin. By using a twin-screw polymerization process and selecting appropriate screws and temperature, an aqueous polyurethane resin with excellent comprehensive properties is obtained;

[0057] (3) The products prepared from the aqueous polyurethane resin emulsion further prepared by using the aqueous polyurethane resin provided by the present invention have hydrolysis resistance, low water absorption, small surface tension, the glass transition temperature of the aqueous polyurethane resin emulsion can be as low as -41 to -55 °C, the water contact angle is as high as 100 to 110°, the hydrolysis retention rate is as high as 80 to 86% and the water absorption is as low as 7.1 to 9.3%, and also have excellent comprehensive properties such as anti-sweating and anti-sticking. Specific Embodiments

[0058] The technical solutions of the present invention will be further described below through specific embodiments. Those skilled in the art should understand that the embodiments are only for helping to understand the present invention and should not be regarded as specific limitations on the present invention.

[0059] Preparation Example 1

[0060] A polyether ester polyol, and its preparation method includes: adding adipic acid, 1,4-butanediol, and a small molecule polyether polyol (number average molecular weight is 800, functionality is 2, purchased from Dow VORANOL 800) into a reaction flask according to a mass ratio of 0.326:0.174:0.5, setting the temperature to 140 °C, and purging with nitrogen for protection, with the nitrogen inlet placed above the liquid level. When the temperature at the top of the distillation column is about 100 °C, dehydration starts; the temperature is raised to 220 °C, controlling the temperature at the top of the distillation column to be 100 °C, adding 4 drops of tetraisopropyl titanate as a catalyst. After reacting for about 3 h, the acid value is tested. When the acid value < 1 mg KOH / g and the water content < 200 ppm, the reaction starts to cool down. The temperature is cooled to 110 °C, the nitrogen is turned off, and the reaction ends to obtain the polyether ester polyol.

[0061] Example 1

[0062] An aqueous polyurethane resin, which comprises the following components by weight:

[0063]

[0064] The preparation method of the aqueous polyurethane resin provided in this example includes the following steps:

[0065] (1) Add the polyester polyol (PBA-2000) into a reaction kettle at 100 °C, and add antioxidant 1010 (Irganox1010), hydroxy polyorganosiloxane (Silok-8815), and the polyether ester polyol (Preparation Example 1) therein to obtain Component A;

[0066] (2) Add 1,4-butanediol into a reaction kettle at 80 °C, and add 2,2-dimethylolpropionic acid therein to obtain Component B;

[0067] (3) After mixing Component A obtained in step (1) and Component B obtained in step (2) through a mixing pump, then mix them with 4,4-diphenylmethane diisocyanate (MDI) at a high speed at the mixing head (wherein, the mass ratio of Component A, Component B, and MDI is 65.55:8.07:26.38), add them into a twin-screw extruder at 250 rpm for reaction, and the temperature settings of each temperature zone are 115 °C, 125 °C, 135 °C, 145 °C, 155 °C, 165 °C, 165 °C, 165 °C, 165 °C, 160 °C, 150 °C, 130 °C, 120 °C, or 110 °C respectively. After underwater pelletizing and drying, the aqueous polyurethane resin is obtained.

[0068] Example 2

[0069] An aqueous polyurethane resin, which is different from that of Example 1 in that the addition amount of hydroxy polyorganosiloxane is 6.35 parts by weight, the addition amount of polyester polyol is 57.11 parts by weight, and the other components, dosages and preparation methods are the same as those of Example 1.

[0070] Example 3

[0071] An aqueous polyurethane resin, which is different from that of Example 1 in that the addition amount of hydroxy polyorganosiloxane is 8.88 parts by weight, the addition amount of polyester polyol is 54.57 parts by weight, and the other components, dosages and preparation methods are the same as those of Example 1.

[0072] Example 4

[0073] An aqueous polyurethane resin, which is different from that of Example 1 in that the addition amount of hydroxy polyorganosiloxane is 12.69 parts by weight, the addition amount of polyester polyol is 50.76 parts by weight, and the other components, dosages and preparation methods are the same as those of Example 1.

[0074] Example 5

[0075] An aqueous polyurethane resin, which comprises the following components by weight:

[0076]

[0077] The preparation method of the aqueous polyurethane resin provided in this example comprises the following steps:

[0078] (1) Add polyester polyol (PBA-2000) to a reaction kettle at 100 °C, and add antioxidant 1010 (Irganox1010), hydroxy polyorganosiloxane (Silok-8815) and polyether ester polyol (Preparation Example 1) therein to obtain Component A;

[0079] (2) Add 1,4-butanediol to a reaction kettle at 80 °C, and add 2,2-dimethylolpropionic acid therein to obtain Component B;

[0080] (3) After mixing Component A obtained in step (1) and Component B obtained in step (2) by a mixing pump, and then mixing them with MDI at high speed at the mixing head (wherein, the mass ratio of Component A, Component B and MDI is 65.11:8.17:26.72), add them to a twin-screw extruder at 250 rpm for reaction. The temperature settings of each temperature zone are 115 °C, 125 °C, 135 °C, 145 °C, 155 °C, 165 °C, 165 °C, 165 °C, 165 °C, 160 °C, 150 °C, 130 °C, 120 °C or 110 °C respectively. After underwater pelletizing and drying, the aqueous polyurethane resin is obtained.

[0081] Example 6

[0082] An aqueous polyurethane resin, which comprises the following components by weight:

[0083]

[0084] The preparation method of the aqueous polyurethane resin provided by this embodiment comprises the following steps:

[0085] (1) Add polyester polyol (PBA-2000) to a reaction kettle at 100 °C, and add antioxidant 1010 (Irganox1010), hydroxy polyorganosiloxane (Silok-8815) and polyether ester polyol (Preparation Example 1) thereto to obtain Component A;

[0086] (2) Add 1,4-butanediol to a reaction kettle at 80 °C, and add 2,2-dimethylolpropionic acid thereto to obtain Component B;

[0087] (3) After mixing the Component A obtained in step (1) and the Component B obtained in step (2) through a mixing pump, mix them with MDI at a high speed at the mixing head (wherein, the mass ratio of Component A, Component B and MDI is 65.33:8.12:26.55), then add them to a twin-screw extruder at 250 rpm for reaction, and the temperature settings of each temperature zone are 115 °C, 125 °C, 135 °C, 145 °C, 155 °C, 165 °C, 165 °C, 165 °C, 165 °C, 160 °C, 150 °C, 130 °C, 120 °C or 110 °C respectively. After underwater pelletizing and drying, the aqueous polyurethane resin is obtained.

[0088] Example 7

[0089] An aqueous polyurethane resin, which comprises the following components by weight:

[0090]

[0091]

[0092] The preparation method of the aqueous polyurethane resin provided by this embodiment comprises the following steps:

[0093] (1) Add polyester polyol (PBA-2000) to a reaction kettle at 100 °C, and add antioxidant 1010 (Irganox1010), hydroxy polyorganosiloxane (Silok-8815) and polyether ester polyol (Preparation Example 1) thereto to obtain Component A;

[0094] (2) Add 1,4-butanediol to a reaction kettle at 80 °C, and add 2,2-dimethylolpropionic acid thereto to obtain Component B;

[0095] (3) After mixing the component A obtained in step (1) and the component B obtained in step (2) by a mixing pump, and then mixing them with MDI at a high speed at the mixing head (wherein, the mass ratio of component A, component B and MDI is 65.77:8.02:26.21), add them to a twin-screw extruder at 250 rpm for reaction. The temperature settings of each temperature zone are 115 °C, 125 °C, 135 °C, 145 °C, 155 °C, 165 °C, 165 °C, 165 °C, 165 °C, 160 °C, 150 °C, 130 °C, 120 °C or 110 °C respectively. After underwater pelletizing and drying, the aqueous polyurethane resin is obtained.

[0096] Example 8

[0097] An aqueous polyurethane resin, which comprises the following components by weight:

[0098]

[0099]

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

[0101] (1) Add polyester polyol (PBA-2000) to a reaction kettle at 100 °C, and add antioxidant 1010 (Irganox1010), hydroxy polyorganosiloxane (Silok-8815) and polyether ester polyol (Preparation Example 1) therein to obtain component A;

[0102] (2) Add 1,4-butanediol to a reaction kettle at 80 °C, and add 3.42 parts by weight of 2,2-dimethylolpropionic acid therein to obtain component B;

[0103] (3) After mixing the component A obtained in step (1) and the component B obtained in step (2) by a mixing pump, and then mixing them with MDI at a high speed at the mixing head (wherein, the mass ratio of component A, component B and MDI is 65.98:7.97:26.05), add them to a twin-screw extruder at 250 rpm for reaction. The temperature settings of each temperature zone are 115 °C, 125 °C, 135 °C, 145 °C, 155 °C, 165 °C, 165 °C, 165 °C, 165 °C, 160 °C, 150 °C, 130 °C, 120 °C or 110 °C respectively. After underwater pelletizing and drying, the aqueous polyurethane resin is obtained.

[0104] Example 9

[0105] An aqueous polyurethane resin, the difference from Example 1 is only that toluene diisocyanate is used to replace 4,4-diphenylmethane diisocyanate, and other components, dosages and preparation methods are the same as those in Example 1.

[0106] Comparative Example 1

[0107] A waterborne polyurethane resin, which is different from Example 1 only in that hydroxy polyorganosiloxane is not added, and other components, dosages and preparation methods are the same as those in Example 1.

[0108] Comparative Example 2

[0109] A waterborne polyurethane resin, which is different from Example 1 only in that polyether ester polyol is not added, and other components, dosages and preparation methods are the same as those in Example 1.

[0110] Comparative Example 3

[0111] A waterborne polyurethane resin, which is different from Example 1 only in that the addition amount of polyether ester polyol is 6 parts by weight, and other components, dosages and preparation methods are the same as those in Example 1.

[0112] Application Example 1

[0113] A waterborne polyurethane resin emulsion, the preparation method of which includes: after mixing 2000 g of waterborne polyurethane resin (Example 1) and 7000 g of methyl ethyl ketone completely, adding 7000 g of water, then adding 73.8 g of TEA, heating to 70 °C, and keeping the temperature constant for 2 h to ensure that the waterborne polyurethane resin is completely emulsified and dispersed, then removing the solvent, cooling, and filtering to obtain a waterborne polyurethane resin emulsion with a solid content of 29.8%.

[0114] Application Examples 2-9

[0115] A waterborne polyurethane resin emulsion, which is different from Application Example 1 only in that the waterborne polyurethane resins obtained in Examples 2-9 are used to replace the waterborne polyurethane resin obtained in Example 1 respectively, and other components, dosages and preparation methods are the same as those in Application Example 1.

[0116] Comparative Application Examples 1-3

[0117] A waterborne polyurethane resin emulsion, which is different from Application Example 1 only in that the waterborne polyurethane resins obtained in Comparative Examples 1-3 are used to replace the waterborne polyurethane resin obtained in Example 1 respectively, and other components, dosages and preparation methods are the same as those in Application Example 1.

[0118] Performance Test:

[0119] (1) Test of waterborne polyurethane resin:

[0120] ① Number average molecular weight and molecular weight distribution: Tested by a molecular weight tester.

[0121] The waterborne polyurethane resins provided in Examples 1-9 and Comparative Examples 1-3 were tested by the above test method, and the results are shown in Table 1:

[0122] Table 1

[0123]

[0124] It can be seen from the data in Table 1 that the number-average molecular weight of the aqueous polyurethane resin provided by the present invention is 60,000 - 63,000, and the molecular weight distribution is 1.6 - 1.93.

[0125] (2) Testing of the aqueous polyurethane emulsion: First, prepare an aqueous polyurethane film. The specific operation is as follows: Scrape the aqueous polyurethane resin emulsion on the release paper with a thickness of 0.2 mm, and completely dry it in an oven at 140 °C to obtain an aqueous polyurethane film with a thickness of about 1.7 mm as the sample to be tested;

[0126] ① Glass transition temperature: Test according to ASTM D3418 standard;

[0127] ② Contact angle: Test according to GB / T 30693 - 2014 standard;

[0128] ③ Hydrolysis retention rate: Cut the obtained aqueous polyurethane film into a fixed shape, place it in a constant temperature and humidity chamber at 70 °C and 95% RH for 7 days. Take out the sample, dry the surface moisture with absorbent paper, dry it in an oven at 100 °C for 30 min, and then place it in a standard laboratory for 3 h for tensile testing. Hydrolysis retention rate = tensile strength after hydrolysis / tensile strength before hydrolysis × 100%;

[0129] ④ Water absorption rate: Place 60 g of the aqueous polyurethane resin emulsion in a specific glass dish, dry it at 120 °C for 30 min, then take out the aqueous polyurethane film in a specific shape, measure the mass m0. Place the film in constant temperature water at 25 °C for 6 h, take it out, dry the surface moisture, and measure the mass m1. Then the water absorption rate = (m1 - m0) / m1 × 100%.

[0130] Test the aqueous polyurethane resin emulsions provided by Application Examples 1 - 9 and Comparative Application Examples 1 - 3 according to the above test methods. The test results are shown in Table 2:

[0131] Table 2

[0132]

[0133]

[0134] It can be seen from the data in Table 2 that the water contact angle of the aqueous polyurethane resin emulsion obtained by using the aqueous polyurethane resin provided by the present invention is relatively large, indicating a relatively low surface tension, and the water absorption rate is low, the glass transition temperature is low, and the hydrolysis retention rate is relatively high, indicating high stability.

[0135] Specifically, the glass transition temperatures of the aqueous polyurethane resin emulsions obtained in Application Examples 1 to 9 are as low as -41 to -55 °C, the water contact angles are as high as 100 to 110°, the hydrolysis retention rates are as high as 80 to 86%, and the water absorption rates are as low as 7.1 to 9.3%.

[0136] By comparing the data of Application Example 1 and Comparative Application Example 1, it can be found that the glass transition temperature of the aqueous polyurethane resin emulsion further prepared from the aqueous polyurethane resin obtained without adding hydroxy polysiloxane is higher, the hydrolysis retention rate is lower, indicating its poor stability, and the water absorption rate is higher, indicating its poor water resistance.

[0137] By comparing the data of Application Example 1 and Comparative Application Example 2 again, it can also be found that not adding polyether ester polyol as a stabilizer will also lead to an increase in the glass transition temperature of the finally prepared aqueous polyurethane resin emulsion, a decrease in the hydrolysis retention rate, and an increase in the water absorption rate.

[0138] Finally, by comparing the data of Application Example 1 and Comparative Application Example 3, it can also be found that adding too much polyether ester polyol will also affect the stability and water resistance of the finally obtained aqueous polyurethane resin emulsion.

[0139] The applicant declares that the present invention illustrates an aqueous polyurethane resin, its preparation method and application through the above embodiments, but the present invention is not limited to the above embodiments, that is, it does not mean that the present invention must rely on the above embodiments to be implemented. Those skilled in the art should understand that any improvement of the present invention, the equivalent substitution of each raw material of the products of the present invention, the addition of auxiliary components, and the selection of specific methods, etc., all fall within the protection scope and the disclosure scope of the present invention.

Claims

1. An aqueous polyurethane resin, characterized in that, The raw materials for preparing the aqueous polyurethane resin include the following components by weight: Diisocyanate 10 - 30 parts by weight Polyester polyol 20 - 70 parts by weight Hydroxyl polyorganosiloxane 2 - 15 parts by weight Hydrophilic chain extender 1 - 5 parts by weight Small molecule diol 1 - 5 parts by weight Stabilizer 1 - 5 parts by weight; The stabilizer is a polyether ester polyol; The preparation method of the polyether ester polyol includes: adding adipic acid, 1,4 - butanediol and small molecule polyether polyol into a reaction flask, heating up, and protecting with nitrogen, with the nitrogen inlet above the liquid level. When the temperature at the top of the distillation column is 100 °C, dehydration starts; when the temperature rises to 220 °C and the temperature at the top of the distillation column is controlled at 100 °C, tetra - isopropyl titanate catalyst is added. After reacting for a period of time, the hydroxyl value and acid value are measured. When the acid value < 1 mg KOH / g, the reaction starts to cool down. When the temperature drops to 110 °C, the nitrogen is turned off and the reaction ends to obtain the polyether ester polyol; The preparation method of the aqueous polyurethane resin includes the following steps: (1) Mix the polyester polyol and the hydroxyl polyorganosiloxane, add the stabilizer and optionally other additives for mixing to obtain mixture A; mix the small molecule diol and the hydrophilic chain extender to obtain mixture B; (2) React mixture A, mixture B and the diisocyanate obtained in step (1) to obtain the aqueous polyurethane resin.

2. The aqueous polyurethane resin according to claim 1, wherein The diisocyanate includes any one or at least two combinations of 4,4 - diphenylmethane diisocyanate, toluene diisocyanate, p - phenylene diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate or hydrogenated 4,4 - diphenylmethane diisocyanate.

3. The aqueous polyurethane resin according to claim 2, wherein, The diisocyanate is 4,4 - diphenylmethane diisocyanate.

4. The aqueous polyurethane resin according to claim 1, characterized in that, The molecular weight of the polyester polyol is 500 - 4000 g / mol.

5. The aqueous polyurethane resin according to claim 1, characterized in that, The polyester polyol includes any one or at least two combinations of polycarbonate diol, polycaprolactone diol, neopentyl glycol adipate diol, hexanediol adipate diol or butanediol adipate diol.

6. The aqueous polyurethane resin according to claim 1, characterized in that, The molecular weight of the hydroxyl polyorganosiloxane is 500 - 3000 g / mol.

7. The aqueous polyurethane resin according to claim 1, characterized in that, The hydroxyl polyorganosiloxane has the structure shown in formula Ⅰ as follows: Wherein, R1 and R2 are each independently selected from any one of C1 - C20 hydrocarbon groups, R3 is selected from any one of C1 - C20 alkyl groups, and n is any integer from 5 to 50.

8. The aqueous polyurethane resin according to claim 1, wherein The hydrophilic chain extender includes a hydroxyl compound containing a hydrophilic group.

9. The aqueous polyurethane resin according to claim 8, wherein, The hydroxyl compound includes any one or at least two combinations of dimethylolbutyric acid, dimethylolpropionic acid, glycerol monosuccinate, glycerol monomaleate, trihydroxypropane monosuccinate, trihydroxypropane monomaleate, methyldiethanolamine, a diol containing a sodium sulfonate group, a polyether diol containing a carboxyl group or a polyester diol containing a carboxyl group.

10. The aqueous polyurethane resin according to claim 9, characterized in that, The hydroxyl compound is dimethylolpropionic acid.

11. The aqueous polyurethane resin according to claim 1, characterized in that, The small molecule diol is selected from any one or a combination of at least two of ethylene glycol, 1,3 - propanediol, 1,4 - butanediol, methylpropanediol, neopentyl glycol, 1,6 - hexanediol, 3 - methyl - 1,5 - pentanediol, 1,4 - bis(β - hydroxyethoxy)benzene, 1,4 - cyclohexanediol, bis(β - hydroxyethyl) terephthalate or benzenedimethanol.

12. The aqueous polyurethane resin according to claim 1, characterized in that, The molecular weight of the polyether ester polyol is 800 - 2000 g / mol.

13. The aqueous polyurethane resin according to claim 1, characterized in that, The molecular weight of the aqueous polyurethane resin is 50000 - 80000 g / mol.

14. The aqueous polyurethane resin according to claim 1, characterized in that, The molecular weight distribution of the aqueous polyurethane resin is 1.5 - 2.

15. The aqueous polyurethane resin according to claim 1, characterized in that, Other auxiliaries are also included in the raw materials for preparing the aqueous polyurethane resin.

16. The aqueous polyurethane resin according to claim 15, wherein The content of other auxiliaries in the raw materials for preparing the aqueous polyurethane resin is 0 - 5 parts by weight and not equal to 0.

17. The aqueous polyurethane resin according to claim 15, characterized in that, The other auxiliaries include any one or a combination of at least two of a primary antioxidant, a secondary antioxidant, a catalyst or a lubricant.

18. A method for preparing the aqueous polyurethane resin according to any one of claims 1 to 17, characterized in that, The preparation method includes the following steps: (1) Mix the polyester polyol and the hydroxy polyorganosiloxane, add a stabilizer and optionally other auxiliaries for mixing to obtain a mixture A; mix the small molecule diol and the hydrophilic chain extender to obtain a mixture B; (2) React the mixture A, mixture B and the diisocyanate obtained in step (1) to obtain the aqueous polyurethane resin.

19. The preparation method according to claim 18, wherein, The mixing temperature for mixing the polyester polyol and the hydroxy polyorganosiloxane in step (1) is 80 - 100 °C.

20. The preparation method according to claim 18, wherein The mixing temperature for adding the stabilizer and optionally other auxiliaries for mixing in step (1) is 80 - 140 °C.

21. The preparation method according to claim 18, characterized in that, The mixing mass ratio of the small molecule diol A and the hydrophilic chain extender in step (1) is (1 - 2):

1.

22. The preparation method according to claim 21, wherein, The mixing mass ratio of the small molecule diol A and the hydrophilic chain extender in step (1) is (1.3 - 1.4):

1.

23. The preparation method according to claim 18, wherein The reaction time in step (2) is 1 - 3 min.

24. The preparation method according to claim 18, characterized in that, The reaction and mixing in step (2) are both carried out in a twin - screw extruder.

25. The preparation method according to claim 24, wherein The length - to - diameter ratio of the screw of the twin - screw extruder is 33 - 64.

26. The preparation method according to claim 25, characterized in that, The length - to - diameter ratio of the screw of the twin - screw extruder is 48 - 60.

27. The preparation method according to claim 24, characterized in that, The temperature of the twin - screw extruder is 100 - 200 °C.

28. The preparation method according to claim 24, characterized in that, The rotation speed of the twin - screw extruder is 150 - 250 rpm.

29. The preparation method according to claim 18, wherein, After the reaction in step (2), it also includes the steps of extrusion, underwater pelletizing and drying.

30. The preparation method according to claim 29, wherein The water temperature for underwater pelletizing is 0 - 30 °C.

31. The preparation method according to claim 29, characterized in that, The drying time is 4 - 8 h.

32. The application of the aqueous polyurethane resin according to any one of claims 1 - 17 in automotive interiors, house decoration or fabric finishing.

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