Waterborne polyurethane-polyurea dispersion as well as preparation method and application thereof

Abstract

The invention provides a waterborne polyurethane-polyurea dispersion as well as a preparation method and application thereof. The polyester polyol is a product prepared by reaction of raw materials comprising the following components: a) polyester polyol; b) a polyisocyanate; c) a component containing at least two groups that are reactive with isocyanate and containing a polyethoxy segment; d) a compound containing at least one group reactive with isocyanate and containing a carboxyl group; e) a hydrophilic chain extender containing sulfonate ions; f) a chain extender containing at least two amino groups; and g) a compound containing at least two amino groups and hydroxyl groups. According to the invention, the low-temperature tortuosity of the waterborne polyurethane-polyurea dispersion can be improved.

Description

Technical Field

[0001] This invention relates to the field of polymer materials technology, and in particular to an aqueous polyurethane-polyurea dispersion, its preparation method, and its application. Background Technology

[0002] The printing industry generally uses polyurethane resin as a printing material, but the traditional preparation process of solvent-based polyurethane generates a large amount of wastewater and waste gas, polluting the environment. In contrast, the preparation process of waterborne polyurethane-polyurea dispersions is simple to operate, highly operable, produces fewer harmful substances, and is safe and environmentally friendly. Furthermore, waterborne polyurethane-polyurea dispersions also possess good room-temperature flexibility, alkali resistance, and jungle resistance, making them widely used in the printing field, such as in shoe material printing.

[0003] However, waterborne polyurethane-polyurea dispersions still suffer from poor low-temperature bending performance, which seriously affects the expansion of their application areas. Summary of the Invention

[0004] This invention provides an aqueous polyurethane-polyurea dispersion, its preparation method, and its application, which helps to improve the low-temperature tortuosity of the aqueous polyurethane-polyurea dispersion.

[0005] This invention provides a method for preparing the above-mentioned waterborne polyurethane-polyurea dispersion, which can obtain a waterborne polyurethane-polyurea dispersion with good low-temperature tortuosity.

[0006] This invention provides an application of the above-mentioned waterborne polyurethane-polyurea dispersion in printing, and the prints made using the above-mentioned waterborne polyurethane-polyurea dispersion have good low-temperature bending properties.

[0007] This invention provides an aqueous polyurethane-polyurea dispersion, which is a product obtained by reacting raw materials containing the following components: a) polyester polyol; b) polyisocyanate; c) a component containing at least two groups reactive to isocyanate and containing a polyethoxy chain segment; d) a compound containing at least one group reactive to isocyanate and containing a carboxyl group; e) a hydrophilic chain extender containing sulfonate ions; f) a chain extender containing at least two amine groups; and g) a compound containing at least two amine groups and containing a hydroxyl group.

[0008] Optionally, the number average molecular weight of the polyester polyol is 1000-15000, preferably 1000-5000, more preferably 1000-3000; and / or, the polyester polyol includes one or more of polyester diol, polyester triol, and polyester tetraol; and / or, the polyisocyanate includes one or more of aliphatic polyisocyanate, alicyclic polyisocyanate, and aromatic polyisocyanate, preferably, the aliphatic polyisocyanate includes aliphatic diisocyanate, wherein the alkyl group in the aliphatic diisocyanate has 4-12 carbon atoms, the alicyclic polyisocyanate includes alicyclic diisocyanate, wherein the cycloalkyl group in the alicyclic diisocyanate has 6-15 carbon atoms, and the aromatic polyisocyanate includes aromatic diisocyanate, wherein the aromatic group in the aromatic diisocyanate has 6-15 carbon atoms; and / or, component c) includes a component containing at least two hydroxyl groups. The polyoxyethylene ether comprises a polyethoxylate, wherein the number average molecular weight of the polyethoxylate is 200-3000, preferably 500-2000; and / or, component d) comprises one or more of 12-hydroxystearic acid, dimethylolpropionic acid, dimethylolbutyric acid, 6-aminohexanoic acid, and L-lysine; and / or, component e) comprises N-(2-aminoethyl)-2-aminoethanesulfonic acid, N-(3-aminopropionic acid)-2-aminoethylolpropionic acid, and L-lysine. The component f) comprises one or more of N-(3-aminopropyl)-3-aminopropanesulfonic acid, N-(2-aminoethyl)-3-aminopropanesulfonic acid; and / or, component g) comprises one or more of ethylenediamine, 1,3-propanediamine, 1,2-propanediamine, 1,4-butanediamine, 1,5-pentanediamine, 1,6-hexanediamine, hexylenediamine, and isophoronediamine; and / or, component g) comprises hydroxyethyl ethylenediamine.

[0009] Optionally, the amounts of components a) to g) satisfy the following: the mass percentage of component a) in the solid mass of the waterborne polyurethane-polyurea dispersion is 60.00% to 90.00%, preferably 70.00% to 88.00%; and / or, the mass percentage of component b) in the solid mass of the waterborne polyurethane-polyurea dispersion is 6.00% to 30.00%, preferably 8.00% to 22.00%; and / or, the mass percentage of component c) in the solid mass of the waterborne polyurethane-polyurea dispersion is 0.30% to 2.00%, preferably 0.50% to 1.50%; and / or, the mass percentage of component d) in the solid mass of the waterborne polyurethane-polyurea dispersion is [not specified in the original text]. The percentage of solids in the polyurea dispersion is 0.20% to 2.00%, preferably 0.30% to 1.00%; and / or, the percentage of component e) in the solids of the aqueous polyurethane-polyurea dispersion is 0.80% to 5.00%, preferably 1.00% to 4.00%; and / or, the percentage of component f) in the solids of the aqueous polyurethane-polyurea dispersion is 0.00% to 5.00%, preferably 1.00% to 3.50%; and / or, the percentage of component g) in the solids of the aqueous polyurethane-polyurea dispersion is 0.15% to 1.00%, preferably 0.20% to 0.50%.

[0010] Optionally, the solid content of the aqueous polyurethane-polyurea dispersion is 35% to 65%, preferably 40% to 60%, more preferably 45% to 60%, the pH of the aqueous polyurethane-polyurea dispersion is 4 to 11, preferably 5 to 10, and the average particle size of the polyurethane-polyurea in the aqueous polyurethane-polyurea dispersion is 100 to 600 nm, preferably 200 to 400 nm.

[0011] This invention provides a method for preparing the aqueous polyurethane-polyurea dispersion as described above, comprising: 1) subjecting the components a), b), c), a first solvent, and a catalyst to a first reaction in an inert atmosphere, wherein the temperature of the first reaction is 50–150°C and the reaction time is 3–6 h, to obtain a polyurethane prepolymer; 2) cooling the polyurethane prepolymer to 35–50°C, adding an aqueous solution of component d), an aqueous solution of component e), and an aqueous solution of component f), and subjecting a second reaction at 35–50°C for 10–30 min, to obtain an intermediate material; 3) adding component g) to the intermediate material and subjecting a third reaction for 5–15 min, and after the reaction is completed, removing the first solvent to obtain the aqueous polyurethane-polyurea dispersion.

[0012] Optionally, the first solvent comprises one or more of acetone, methyl isobutyl ketone, butanone, tetrahydrofuran, dioxane, acetonitrile, dipropylene glycol dimethyl ether, and 1-methyl-2-pyrrolidone; and / or, the catalyst comprises one or more of triethylamine, 1,4-diazabicyclo-[2,2,2]octane, dibutyltin oxide, tin dioctanoate, dibutyltin dilaurate, bis-(2-ethylhexanoate)tin, bismuth neodecanoate, and bismuth 2-ethylhexanoate.

[0013] Optionally, the pressure of the first reaction is 0-5 MPa, preferably 0-1 MPa.

[0014] Optionally, before step 2), the method further includes adding a second solvent to the polyurethane prepolymer for dilution, then cooling the diluted polyurethane prepolymer to 35-50°C, adding an aqueous solution of component d), an aqueous solution of component e), and an aqueous solution of component f), and carrying out a second reaction at 35-50°C for 10-30 minutes to obtain an intermediate material; the mass of the first solvent and the second solvent is 0.8-3.0 times, preferably 1.0-2.0 times, the solid mass in the aqueous polyurethane-polyurea dispersion.

[0015] Optionally, before step 3), deionized water is added to the intermediate material for dispersion under stirring, wherein the stirring speed is 800-1500 r / min and the stirring time is 5-15 min; then the component g) is added to the dispersed intermediate material for a third reaction for 5-15 min; after the reaction is completed, the solvent is removed to obtain the waterborne polyurethane-polyurea dispersion.

[0016] This invention provides an application of an aqueous polyurethane-polyurea dispersion in printing, wherein the aqueous polyurethane-polyurea dispersion comprises the aqueous polyurethane-polyurea dispersion as described above or the aqueous polyurethane-polyurea dispersion obtained according to the preparation method described above.

[0017] This invention provides an aqueous polyurethane-polyurea dispersion, its preparation method, and its application. By introducing carboxyl groups into the aqueous polyurethane-polyurea dispersion, the polarity of the aqueous polyurethane-polyurea is increased, and its intermolecular forces are enhanced. This can improve the cohesive force of the aqueous polyurethane-polyurea dispersion while maintaining its softness, thus helping to improve its bending resistance. Detailed Implementation

[0018] To enable those skilled in the art to better understand the present invention, the present invention will be further described in detail below. The specific embodiments listed below are merely descriptions of the principles and features of the present invention, and the examples are only for explaining the present invention and are not intended to limit the scope of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0019] In the printing industry, polyurethane resin is generally used as a printing material. For example, the shoe material printing industry uses waterborne polyurethane-polyurea dispersion (waterborne polyurethane resin) as a printing material. However, the low-temperature performance of waterborne polyurethane-polyurea dispersion in the prior art is poor, specifically, its flexural resistance is poor at low temperatures. The inventors of this invention have introduced carboxyl groups into the waterborne polyurethane-polyurea dispersion, increasing the polarity of the waterborne polyurethane-polyurea and enhancing its intermolecular forces. This can improve its cohesive force while maintaining the softness of the waterborne polyurethane-polyurea dispersion, thus helping to improve its flexural resistance. In addition, in the application of waterborne polyurethane-polyurea dispersion, it is necessary to coat the waterborne polyurethane-polyurea dispersion onto the substrate and then coat it with a carboxyl-containing ink. The carboxyl groups in the waterborne polyurethane-polyurea dispersion can enhance the adhesion between the waterborne polyurethane-polyurea dispersion and the carboxyl-containing ink, which also helps to increase the flexural resistance.

[0020] Based on this, the first aspect of the present invention provides an aqueous polyurethane-polyurea dispersion, which is a product obtained by reacting raw materials containing the following components: a) polyester polyol; b) polyisocyanate; c) a component containing at least two groups reactive to isocyanate and containing a polyethoxy chain segment; d) a compound containing at least one group reactive to isocyanate and containing a carboxyl group; e) a hydrophilic chain extender containing sulfonate ions; f) a chain extender containing at least two amine groups; and g) a compound containing at least two amine groups and containing a hydroxyl group.

[0021] According to the inventors' research and analysis, introducing carboxyl groups into the waterborne polyurethane-polyurea segments can increase the polarity of the waterborne polyurethane-polyurea, enhance its intermolecular forces, and improve its cohesiveness while maintaining the softness of the waterborne polyurethane-polyurea dispersion. This, in turn, helps to improve its flexural resistance, giving it better flexural resistance at low temperatures, as well as good resistance to alkalis, jungles, and room temperature flexural stress. Furthermore, in the application of waterborne polyurethane-polyurea dispersions, after coating the waterborne polyurethane-polyurea dispersion onto a substrate, a carboxyl-containing ink is coated on top. The carboxyl groups in the waterborne polyurethane-polyurea dispersion can enhance the adhesion between the waterborne polyurethane-polyurea dispersion and the carboxyl-containing ink, which also helps to increase flexural resistance, giving it better flexural resistance at low temperatures, as well as good resistance to alkalis, jungles, and room temperature flexural stress. Therefore, the waterborne polyurethane-polyurea dispersion of the present invention has good flexural resistance at low temperatures, as well as good resistance to alkalis, jungles, and room temperature flexural stress.

[0022] In component a) above, the number average molecular weight of the polyester polyol can be 1000-15000, preferably 1000-5000, and more preferably 1000-3000. This is beneficial for improving the flexural resistance of the waterborne polyurethane-polyurea dispersion at low temperatures.

[0023] Polyester polyols may include one or more of polyester diols, polyester triols, and polyester tetraols. Preferably, the polyester polyols include linear polyester diols and / or microbranched polyester diols.

[0024] The aforementioned polyester polyols can be obtained by dehydration condensation reaction of polyols with carboxylic acids and / or acid anhydrides.

[0025] The aforementioned carboxylic acids and / or anhydrides may include one or more of aliphatic dicarboxylic acids or polycarboxylic acids or their corresponding anhydrides, alicyclic dicarboxylic acids or polycarboxylic acids or their corresponding anhydrides, and aromatic dicarboxylic acids or polycarboxylic acids or their corresponding anhydrides. Specifically, carboxylic acids and / or anhydrides may include one or more of succinic acid, methylsuccinic acid, glutaric acid, adipic acid, pimelic acid, octanoic acid, azelaic acid, sebacic acid, nonanedicarboxylic acid, decanedicarboxylic acid, terephthalic acid, isophthalic acid, phthalic acid, tetrahydrophthalic acid, hexahydrophthalic acid, cyclohexanedicarboxylic acid, maleic acid, fumaric acid, malonic acid, trimellitic acid, phthalic anhydride, trimellitic anhydride, and succinic anhydride.

[0026] Polyols may include one or more of alicyclic dihydroxy compounds and / or polyhydroxy compounds, and aromatic dihydroxy compounds and / or polyhydroxy compounds. Specifically, polyols may include one or more of ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,4-butanediol, 1,3-butanediol, 2,3-butanediol, 1,5-pentanediol, 1,6-hexanediol, 2,2-dimethyl-1,3-propanediol, neopentanediol, 1,4-dihydroxycyclohexane, 1,4-dimethylolcyclohexane, 1,8-octanediol, 1,10-decanediol and 1,12-dodecanediol, diethylene glycol, 2-methyl-1,3-propanediol, and hexanediol. Furthermore, polyols may also include one or more of trimethylolpropane, glycerol, or pentaerythritol with higher functionality.

[0027] Preferably, one or more of adipic acid, isophthalic acid, and terephthalic acid can be used as carboxylic acid raw materials, and they can be subjected to dehydration condensation reaction with one or more of neopentyl glycol, diethylene glycol, 2-methyl-1,3-propanediol, and hexanediol to prepare polyester polyol.

[0028] The aforementioned polyester polyols may also include homopolymers or copolymers of lactones, specifically obtained by ring-opening polymerization of lactones or mixtures of lactones with suitable difunctional or higher-functionality low-molecular-weight polyols. The lactones may include one or more of butyrolactone, ε-caprolactone, and methyl-ε-caprolactone; the type of difunctional or higher-functionality low-molecular-weight polyol can be the same as the aforementioned polyols. Preferably, one or more of 1,4-butanediol, 1,6-hexanediol, and 2,2-dimethyl-1,3-propanediol can be used as polyols to prepare linear polyester polyols by ring-opening reaction with ε-caprolactone.

[0029] Furthermore, the aforementioned polyester polyol may also include hydroxyl-containing polycarbonates prepared by reacting diols and carbonates. The diols here may include 1,4-butanediol and / or 1,6-hexanediol, and the carbonates may include diaryl carbonates or dialkyl carbonates, wherein the diaryl carbonates may include diphenyl carbonates, and the dialkyl carbonates may include dimethyl carbonates. Preferably, 1,6-hexanediol may be reacted with dimethyl carbonates to prepare polycarbonates for use as component a).

[0030] In component b), the polyisocyanate may include one or more of aliphatic polyisocyanate, alicyclic polyisocyanate, and aromatic polyisocyanate.

[0031] Preferably, the aliphatic polyisocyanate may include an aliphatic diisocyanate (one or more of an aliphatic isocyanate having two isocyanate groups). The number of carbon atoms in the alkyl group of the above-mentioned aliphatic diisocyanate may be 4 to 12, for example 4, 5, 6, 7, 8, 9, 10 or 12, that is, the aliphatic diisocyanate may be represented by Y(NCO)2, where Y is a divalent aliphatic hydrocarbon group containing 4 to 12 carbon atoms.

[0032] Preferably, the alicyclic polyisocyanate may include an alicyclic diisocyanate (one or more of alicyclic isocyanates having two isocyanate groups), wherein the number of carbon atoms in the cycloalkyl group of the alicyclic diisocyanate may be 6 to 15, for example 6, 7, 8, 9, 10, 11, 12, 13, 14 or 15, that is, the alicyclic diisocyanate may be represented by X(NCO)2, where X is a divalent alicyclic hydrocarbon group containing 6 to 15 carbon atoms.

[0033] Preferably, the aromatic polyisocyanate may include an aromatic diisocyanate, which may include a divalent aromatic hydrocarbon group or a divalent aryl aliphatic hydrocarbon group. The number of carbon atoms in the divalent aromatic hydrocarbon group may be 6 to 15, for example, 6, 7, 8, 9, 10, 11, 12, 13, 14 or 15. The number of carbon atoms in the divalent aryl aliphatic hydrocarbon group may be 7 to 15, for example, 7, 8, 9, 10, 11, 12, 13, 14 or 15. That is, the aromatic polyisocyanate may be represented by Z(NCO)2, where Z may include a divalent aromatic hydrocarbon group containing 6 to 15 carbon atoms or a divalent aryl aliphatic hydrocarbon group containing 7 to 15 carbon atoms.

[0034] The polyisocyanate in component b) may include diisocyanate, specifically, the diisocyanate may include one or more of the following: hexamethylene diisocyanate, pentamethylene diisocyanate, dodecamethylene diisocyanate, 1,4-cyclohexane diisocyanate, isophorone diisocyanate, 4,4'-dicyclohexylmethane diisocyanate, 4,4'-dicyclohexylpropane diisocyanate, 1,4-phenyl diisocyanate, 2,4-toluene diisocyanate, 2,6-toluene diisocyanate, 4,4'-diphenylmethane diisocyanate, 2,2'-diphenylmethane diisocyanate, 2,4'-diphenylmethane diisocyanate, tetramethylxylyl diisocyanate, and terephthalic diisocyanate.

[0035] Component c) comprises a component containing at least two groups reactive to isocyanates and containing a polyethoxy group (a bifunctional or polyfunctional nonionic hydrophilic compound component). Preferably, component c) comprises a polyoxyolefin ether containing at least two hydroxyl groups. Initiators used in the preparation of this polyoxyolefin ether include, but are not limited to, saturated triols, such as glycerol and / or trimethylolpropane.

[0036] Furthermore, the polymerization unit of the above-mentioned polyoxyalkylene ether may include propylene oxide and / or ethylene oxide, preferably ethylene oxide, that is, the above-mentioned polyoxyalkylene ether includes polyethoxy ether (which can be understood as component c), preferably a bifunctional or polyfunctional polyethoxy ether.

[0037] The number-average molecular weight of the polyethoxy ether can be 200 to 3000, preferably 500 to 2000.

[0038] Furthermore, the number of ethylene oxide alkyl groups in the above-mentioned polyethoxy ether molecule (polyoxyethylene ether molecule) can be 4 to 100, preferably 10 to 45.

[0039] In some embodiments, the above composition c) is preferably a bifunctional or polyfunctional polyethoxy ether with a number average molecular weight of 200 to 3000 and 4 to 100 ethylene oxide alkyl groups, more preferably a bifunctional or polyfunctional polyethoxy ether with a number average molecular weight of 500 to 2000 and 10 to 45 ethylene oxide alkyl groups.

[0040] Component d) includes a compound containing at least one group that is reactive to isocyanates and contains a carboxyl group, that is, component d) includes one or more compounds containing a carboxyl group and at least one isocyanate reactive group.

[0041] In component d), the groups that are reactive to isocyanates may include hydroxyl and / or amine groups.

[0042] Specifically, component d) may include one or more of 12-hydroxystearic acid, dimethylolpropionic acid, dimethylolbutyric acid, 6-aminohexanoic acid, and L-lysine, preferably L-lysine.

[0043] Component e) includes a hydrophilic chain extender containing sulfonate ions. This hydrophilic chain extender containing sulfonate ions (a hydrophilic compound containing ionic groups) may include one or more of alkali metal salts, alkaline earth metal salts, and ammonium salts containing potentially ionic groups. Preferably, the hydrophilic chain extender containing sulfonate ions may contain 2 to 3 isocyanate (NCO) reactive functional groups; more preferably, the hydrophilic chain extender containing sulfonate ions may include one or more of N-(2-aminoethyl)-2-aminoethanesulfonic acid, N-(3-aminopropyl)-2-aminoethanesulfonic acid, N-(3-aminopropyl)-3-aminopropanesulfonic acid, and N-(2-aminoethyl)-3-aminopropanesulfonic acid.

[0044] Component f) includes a chain extender containing at least two amino groups. Specifically, component f) may include one or more of ethylenediamine, 1,3-propanediamine, 1,2-propanediamine, 1,4-butanediamine, 1,5-pentanediamine, 1,6-hexanediamine, hexylenediamine, and isophoronediamine, preferably ethylenediamine and / or isophoronediamine.

[0045] Component g) comprises a compound containing at least two amino groups and a hydroxyl group, that is, component g) comprises a compound (low molecular weight compound) containing a hydroxyl group and at least two isocyanate (NCO) reactive functional groups (amino groups). Preferably, component g) comprises hydroxyethyl ethylenediamine.

[0046] The aqueous polyurethane-polyurea dispersion of this invention is a product obtained by reacting raw materials containing components a) to g), wherein the amounts of components a) to g) satisfy the following:

[0047] The mass percentage of component a) in the solid mass of the waterborne polyurethane-polyurea dispersion can be 60% to 90%, preferably 70% to 88%; the mass percentage of component b) in the solid mass of the waterborne polyurethane-polyurea dispersion can be 6% to 30%, preferably 8% to 22%; the mass percentage of component c) in the solid mass of the waterborne polyurethane-polyurea dispersion can be 0.3% to 2.0%, preferably 0.5% to 1.5%; and the mass percentage of component d) in the solid mass of the waterborne polyurethane-polyurea dispersion can be 0. The mass percentage of component e) in the solid mass of the waterborne polyurethane-polyurea dispersion can be 0.8% to 5.0%, preferably 1.0% to 4.0%; the mass percentage of component f) in the solid mass of the waterborne polyurethane-polyurea dispersion can be 0.0% to 5.0%, preferably 1.0% to 3.5%; the mass percentage of component g) in the solid mass of the waterborne polyurethane-polyurea dispersion can be 0.15% to 1.00%, preferably 0.20% to 0.50%.

[0048] In some embodiments, the solid content of the waterborne polyurethane-polyurea dispersion is 35%–65%, preferably 45%–60%, the pH of the waterborne polyurethane-polyurea dispersion is 4–11, preferably 5–10, and the average particle size of the polyurethane-polyurea in the waterborne polyurethane-polyurea dispersion is 100–600 nm, preferably 200–400 nm. This waterborne polyurethane-polyurea dispersion exhibits high stability, good flexural resistance at low temperatures, and also good resistance to alkalis, thorns, and flexural stress at room temperature.

[0049] This invention also provides a method for preparing the above-mentioned waterborne polyurethane-polyurea dispersion, comprising: 1) subjecting components a), b), c), a first solvent, and a catalyst to a first reaction in an inert atmosphere, wherein the temperature of the first reaction is 50–150°C and the time of the first reaction is 3–6 h, to obtain a polyurethane prepolymer; 2) cooling the polyurethane prepolymer to 35–50°C, adding an aqueous solution of component d), an aqueous solution of component e), and an aqueous solution of component f), and subjecting a second reaction at 35–50°C for 10–30 min, to obtain an intermediate material; 3) adding component g) to the intermediate material and subjecting a third reaction for 5–15 min, and after the reaction is completed, removing the solvent to obtain the waterborne polyurethane-polyurea dispersion.

[0050] According to the inventor's research and analysis: In the above preparation method, components a), b), and c) are first subjected to a first reaction to obtain a polyurethane prepolymer; then component d) is reacted with the polyurethane prepolymer to introduce carboxyl groups, while components e) and f) are reacted with the polyurethane prepolymer as chain extenders; finally, component g) is used to introduce hydroxyl groups that are beneficial for subsequent curing treatment, thereby obtaining an aqueous polyurethane-polyurea dispersion. This aqueous polyurethane-polyurea dispersion has high polarity, strong intermolecular forces, and high softness and cohesiveness. In addition, after being used for printing, it has strong adhesion to the upper ink layer. Therefore, this aqueous polyurethane-polyurea dispersion has good flexural resistance, as well as good resistance to alkali, rust, and room temperature flexural stress. In summary, the preparation method of this invention is simple and easy to implement, does not generate a large amount of wastewater and waste gas, has high environmental protection significance, and more importantly, helps to obtain an aqueous polyurethane-polyurea dispersion with good flexural resistance at low temperatures, as well as good resistance to alkali, rust, and room temperature flexural stress.

[0051] In step 1) above, the endpoint of the first reaction can be determined by the content of isocyanate in the mixture of the first reaction. That is, the content of NCO groups in the prepolymer is directly tested by using a ZETA potentiometric titrator according to the principle of acid-base titration. When the actual NCO content is lower than the theoretical NCO content, the reaction endpoint is reached and the first reaction can be terminated.

[0052] For example, the temperature of the first reaction can be a range of 50°C, 60°C, 80°C, 100°C, 120°C, 140°C, 150°C or any two of these, and the time of the first reaction can be a range of 3h, 4h, 5h, 6h or any two of these.

[0053] Furthermore, the pressure of the first reaction can be 0 to 5 MPa, for example, 0 MPa, 1 MPa, 2 MPa, 3 MPa, 4 MPa, 5 MPa or any combination thereof, preferably 0 to 1 MPa.

[0054] In some embodiments, nitrogen is used as an inert atmosphere.

[0055] The first solvent can be a solvent that is easy to remove from the reaction system, for example, by distillation to remove part or all of the solvent from the reaction system. Specifically, the first solvent may include one or more of acetone, methyl isobutyl ketone, butanone, tetrahydrofuran, dioxane, acetonitrile, dipropylene glycol dimethyl ether, and 1-methyl-2-pyrrolidone, preferably acetone and / or butanone, more preferably acetone.

[0056] The catalyst may include one or more of triethylamine, 1,4-diazabicyclo-[2,2,2]octane, dibutyltin oxide, tin dioctanoate or dibutyltin dilaurate, bis-(2-ethylhexanoate)tin, bismuth neodecanoate, and bismuth 2-ethylhexanoate, preferably bismuth neodecanoate or bismuth 2-ethylhexanoate, and more preferably bismuth neodecanoate.

[0057] In addition, in step 1), the amount of catalyst used can be 30-1000 ppm based on the non-volatile solid components in the first reaction system.

[0058] Before step 2), the process may further include adding a second solvent to the polyurethane prepolymer to dilute it, thereby obtaining a diluted polyurethane prepolymer.

[0059] The polyurethane prepolymer (or diluted polyurethane prepolymer) is then cooled to 35–50°C, and aqueous solutions of components d), e), and f) are added. A second reaction is then carried out at 35–50°C for 10–30 minutes to obtain an intermediate material. Understandably, the addition of these aqueous solutions should be slow and gradual, avoiding excessively rapid addition.

[0060] The second solvent can be a solvent that is easily removed from the reaction system, for example, by distillation to remove part or all of the solvent from the reaction system. Specifically, the second solvent may include one or more of acetone, methyl isobutyl ketone, butanone, tetrahydrofuran, dioxane, acetonitrile, dipropylene glycol dimethyl ether, and 1-methyl-2-pyrrolidone, preferably acetone and / or butanone, more preferably acetone. For ease of operation, the first and second solvents may be selected from the same solvent.

[0061] In the above operation, the mass (total amount) of the first solvent and the second solvent can be 0.8 to 3.0 times the solid mass (total solid content) of the waterborne polyurethane-polyurea dispersion, for example, 0.8 times, 1.0 times, 2.0 times, 3.0 times, or any combination thereof, preferably 1.0 to 2.0 times. This helps the raw materials to be better dispersed in the reaction system, which facilitates the improvement of the reaction effect and thus helps to improve the flexural resistance of the waterborne polyurethane-polyurea dispersion at low temperature.

[0062] Before step 3), deionized water may be added to the intermediate material for dispersion while stirring. After dispersion, the dispersed intermediate material is obtained. The stirring speed can be 800-1500 r / min and the stirring time can be 5-15 min.

[0063] Then, add component g to the intermediate material (or the dispersed intermediate material) and carry out the third reaction for 5-15 minutes. After the reaction is completed, remove the first solvent (or the first solvent and the second solvent) to obtain the waterborne polyurethane-polyurea dispersion.

[0064] The process of removing the first solvent (or the first solvent and the second solvent) described above can be carried out by vacuum distillation to remove (remove) the first solvent (or the first solvent and the second solvent).

[0065] This invention also provides an application of the above-mentioned waterborne polyurethane-polyurea dispersion in printing.

[0066] The aforementioned printing may include printing on shoe materials.

[0067] Prints made from the above-mentioned waterborne polyurethane-polyurea dispersion (especially for shoe materials) have good flexural resistance at low temperatures, as well as good resistance to alkalis, jungles, and room temperature flexural stress.

[0068] The present invention will be further described below through specific embodiments and comparative examples. Unless otherwise specified, the reagents, materials, and instruments used below are all conventional reagents, materials, and instruments, all of which are commercially available. The reagents and materials involved can also be synthesized by conventional synthetic methods. The sources of some materials are explained below:

[0069] Polyester diols: WHP1056 and WHP1556, with number average molecular weights of 1000 and 1500 respectively, are both obtained by dehydration condensation reaction of 1,6-adipic acid with 1,6-hexanediol and neopentyl glycol in different proportions; WHP305, with a number average molecular weight of 3000, is obtained by dehydration condensation reaction of 1,6-adipic acid with neopentyl glycol in a specific proportion; all of the above are produced by Wanhua Chemical Group Co., Ltd.

[0070] Polyethoxy ethers (monohydroxy polyethoxy ethers): MPEG1200, with a number average molecular weight of 1200, is a monohydroxy polyethoxy ether prepared by ring-opening polymerization of ethylene oxide and methanol end-capping; N120, with a number average molecular weight of 1000, is a dihydroxy polyethoxy ether prepared by ring-opening polymerization of ethylene oxide and TMP end-capping; both are produced by Wanhua Chemical Group Co., Ltd.

[0071] 12-Hydroxystearic acid: Sinopharm Group;

[0072] L-Lysine (50% aqueous solution): Hebei Tikham Biotechnology Co., Ltd.;

[0073] 4,4-Dicyclohexylmethane diisocyanate (HMDI): Wanhua Chemical Group Co., Ltd.;

[0074] Isoflurone diisocyanate (IPDI): Wanhua Chemical Group Co., Ltd.;

[0075] Hexamethylene diisocyanate (HDI): Wanhua Chemical Group Co., Ltd.;

[0076] Ethylenediamine (industrial grade): Yangzi Petrochemical-BASF Co., Ltd.;

[0077] Hydroxyethyl ethylenediamine (industrial grade): Wanhua Chemical Group Co., Ltd.

[0078] Sodium N-(2-aminoethyl)-2-aminoethanesulfonate (Vestamin A95, 50% aqueous solution): Evonik Industries, Germany;

[0079] Isophorone diamine (IPDA, industrial grade): Wanhua Chemical Group Co., Ltd.

[0080] Bismuth neodecanoate catalyst (8108): Leading US chemical company.

[0081] Example 1

[0082] This embodiment provides a method for preparing an aqueous polyurethane-polyurea dispersion, including:

[0083] 1) A polyester diol WHP1556 (a) with a number average molecular weight of 1500, hexamethylene diisocyanate and isoflurane diisocyanate (b), monohydroxy polyethoxy ether MPEG1200 (c) with a number average molecular weight of 1200, acetone (first solvent) and bismuth neodecanoate (catalyst) were subjected to a first reaction in nitrogen atmosphere. The temperature of the first reaction was 80°C, the pressure was 0 MPa, and the time of the first reaction was 5 h, to obtain a polyurethane prepolymer.

[0084] 2) Add acetone to the polyurethane prepolymer for dilution, then cool the diluted polyurethane prepolymer to 35-50℃. Dilute the aqueous solution of L-lysine (d) (where the mass percentage of L-lysine is 50%), N-(2-aminoethyl)-2-aminoethanesulfonic acid (e) and isophorone diamine (f) with pure water (the mass of pure water is 4.5 times the sum of the mass of N-(2-aminoethyl)-2-aminoethanesulfonic acid (e) and isophorone diamine (f)) and slowly add it to the prepolymer. Under stirring, maintain the temperature at 35-50℃ for the second reaction for 20 minutes to obtain the intermediate material.

[0085] 3) Add deionized water to the intermediate material under stirring to disperse it. After dispersion, the dispersed intermediate material is obtained. The stirring speed can be 1000 r / min, the water addition time is 10 min, and the mass of deionized water is 1 times the mass of solids in the waterborne polyurethane-polyurea dispersion.

[0086] 4) Add an aqueous solution of hydroxyethyl ethylenediamine (g) to the dispersed intermediate material and carry out the third reaction for 5 min. After the reaction is completed, remove acetone by distillation to obtain an aqueous polyurethane-polyurea dispersion.

[0087] In steps 1) and 2), the mass of acetone is 1.5 times the mass of solids in the aqueous polyurethane-polyurea dispersion.

[0088] In step 1), based on the non-volatile solid components in the first reaction system, the amount of catalyst can be 500 ppm;

[0089] The mass percentage of component a) in the solids of the waterborne polyurethane-polyurea dispersion is 81.4%; the mass percentage of component b) in the solids of the waterborne polyurethane-polyurea dispersion is 14.7%; the mass percentage of component c) in the solids of the waterborne polyurethane-polyurea dispersion is 0.63%; the mass percentage of component d) in the solids of the waterborne polyurethane-polyurea dispersion is 1.01%; the mass percentage of component e) in the solids of the waterborne polyurethane-polyurea dispersion is 2.1%; the mass percentage of component f) in the solids of the waterborne polyurethane-polyurea dispersion is 0.00%; and the mass percentage of component g) in the solids of the waterborne polyurethane-polyurea dispersion is 0.16%.

[0090] Referring to the process of Example 1, the aqueous polyurethane-polyurea dispersions of Examples 2 to 7 were prepared. The types of components a), b), c), d), e), f), and g) of each example are summarized in Table 1. The percentage of the mass of components a), b), c), d), e), f), and g) to the solid mass of the aqueous polyurethane-polyurea dispersion, the amount of catalyst used, and the multiple of the mass of deionized water in step 3) to the solid mass of the aqueous polyurethane-polyurea dispersion are summarized in Table 2. The parameters of the temperature of the first reaction, the time of the first reaction, the pressure of the first reaction, the type of the first solvent, the type of the second solvent, the multiple of the mass of the first solvent and the second solvent to the solid mass of the aqueous polyurethane-polyurea dispersion, the type of catalyst, the temperature of the second reaction, the time of the second reaction, the time of the third reaction, the rotation speed and time of adding deionized water for dispersion are summarized in Table 3.

[0091] Table 1

[0092]

[0093] Table 2

[0094]

[0095] Table 3

[0096]

[0097]

[0098] Test case

[0099] The following parameters of each embodiment and comparative example were tested:

[0100] Physical property testing:

[0101] 1) Solid content of waterborne polyurethane-polyurea dispersion: Weigh a quantitative amount of emulsion (i.e., waterborne polyurethane-polyurea dispersion) using aluminum foil, dry it in an oven at 150℃ for about 30 minutes, and accurately weigh the mass after drying. Solid content S = mass after drying / mass of emulsion.

[0102] 2) pH of waterborne polyurethane-polyurea dispersion: Measured accurately using a pH meter;

[0103] 3) Average particle size of waterborne polyurethane-polyurea dispersion: The emulsion (i.e., waterborne polyurethane-polyurea dispersion) and pure water were diluted with pure water at a volume ratio of 1:2500, and then measured using a Malvern particle size analyzer.

[0104] Application performance testing:

[0105] Sample preparation: The prepared waterborne polyurethane emulsion is mixed with curing agent, hand feel agent, thickener and other additives according to a specific formula, stirred evenly, and the paste is applied to a specific substrate by screen printing, dried, and then another layer of paste is applied on the coating in the same way, dried, and the finished product is obtained.

[0106] 4) Low temperature bending resistance: Cut the prepared printed sample into a rectangle of about 3*6cm, and clamp it correctly in the sample clamp on the bending tester according to the instructions. Set the heat preservation box to -20℃ and start the bending test. Record the cracking of the sample surface every 10,000 times.

[0107] 5) Room temperature flexural strength: Tested at room temperature according to the low temperature flexural strength test method;

[0108] 6) Alkali resistance: Immerse the sample in a 10% NaOH aqueous solution and record the changes in the sample surface over time. If it remains unchanged, it is qualified; if it becomes sticky and easily falls off, it is unqualified.

[0109] 7) Jungle resistance: Place the sample in a constant temperature and humidity chamber at 70℃ and 90% humidity. Observe the surface condition of the sample after 3 days. If there is no change on the surface, it is qualified. If the surface brightness disappears and it becomes sticky, it is unqualified.

[0110] Test results

[0111] Table 4. Results of physical property tests and application performance tests

[0112]

[0113] Results analysis:

[0114] Analysis of the various embodiments and Comparative Example 1 shows that introducing an appropriate amount of carboxyl groups into the polyurethane chain segment can significantly improve the low-temperature bending performance of printing.

[0115] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A waterborne polyurethane-polyurea dispersion, characterized in that, It is a product obtained by reacting raw materials containing the following components: a) Polyester polyols; b) Polyisocyanates; c) A component containing at least two groups that are reactive to isocyanates and containing polyethoxy segments; d) A compound containing at least one group that is reactive with isocyanates and also contains a carboxyl group; e) Hydrophilic chain extenders containing sulfonate ions; f) Chain extenders containing at least two amine groups; g) A compound containing at least two amine groups and a hydroxyl group.

2. The aqueous polyurethane-polyurea dispersion according to claim 1, characterized in that, The number average molecular weight of the polyester polyol is 1000-15000, preferably 1000-5000, and more preferably 1000-3000; And / or, the polyester polyol includes one or more of polyester diol, polyester triol, and polyester tetraol; And / or, the polyisocyanate includes one or more of aliphatic polyisocyanate, alicyclic polyisocyanate, and aromatic polyisocyanate. Preferably, the aliphatic polyisocyanate includes aliphatic diisocyanate, wherein the alkyl group in the aliphatic diisocyanate has 4 to 12 carbon atoms; the alicyclic polyisocyanate includes alicyclic diisocyanate, wherein the cycloalkyl group in the alicyclic diisocyanate has 6 to 15 carbon atoms; and the aromatic polyisocyanate includes aromatic diisocyanate, wherein the aromatic group in the aromatic diisocyanate has 6 to 15 carbon atoms. And / or, component c) comprises a polyoxyalkylene ether containing at least two hydroxyl groups, the polyoxyalkylene ether comprising a polyethoxy ether having a number-average molecular weight of 200 to 3000, preferably 500 to 2000; And / or, component d) comprises one or more of 12-hydroxystearic acid, dimethylolpropionic acid, dimethylolbutyric acid, 6-aminohexanoic acid, and L-lysine; And / or, component e) includes one or more of N-(2-aminoethyl)-2-aminoethanesulfonic acid, N-(3-aminopropyl)-2-aminoethanesulfonic acid, N-(3-aminopropyl)-3-aminopropanesulfonic acid, and N-(2-aminoethyl)-3-aminopropanesulfonic acid. And / or, the component f) includes one or more of ethylenediamine, 1,3-propanediamine, 1,2-propanediamine, 1,4-butanediamine, 1,5-pentanediamine, 1,6-hexanediamine, hexylenediamine, and isophoronediamine; And / or, the component g) includes hydroxyethyl ethylenediamine.

3. The aqueous polyurethane-polyurea dispersion according to claim 1, characterized in that, The amounts of components a) to g) satisfy the following: The mass percentage of component a) in the solid mass of the aqueous polyurethane-polyurea dispersion is 60.00% to 90.00%, preferably 70.00% to 88.00%. And / or, the mass percentage of component b) of the waterborne polyurethane-polyurea dispersion is 6.00% to 30.00% of the solid mass, preferably 8.00% to 22.00%; And / or, the mass percentage of component c) of the waterborne polyurethane-polyurea dispersion is 0.30% to 2.00% of the solid mass, preferably 0.50% to 1.50%; And / or, the mass percentage of component d) of the waterborne polyurethane-polyurea dispersion is 0.20% to 2.00%, preferably 0.30% to 1.00% of the solid mass; And / or, the mass percentage of component e) of the waterborne polyurethane-polyurea dispersion is 0.80% to 5.00% of the solid mass, preferably 1.00% to 4.00%; And / or, the mass percentage of component f) of the waterborne polyurethane-polyurea dispersion is 0.00% to 5.00% of the solid mass, preferably 1.00% to 3.50%; And / or, the mass percentage of the component (g) to the solid mass of the aqueous polyurethane-polyurea dispersion is 0.15% to 1.00%, preferably 0.20% to 0.50%.

4. The aqueous polyurethane-polyurea dispersion according to claim 1, characterized in that, The solid content of the aqueous polyurethane-polyurea dispersion is 35% to 65%, preferably 40% to 60%, more preferably 45% to 60%, the pH of the aqueous polyurethane-polyurea dispersion is 4 to 11, preferably 5 to 10, and the average particle size of the polyurethane-polyurea in the aqueous polyurethane-polyurea dispersion is 100 to 600 nm, preferably 200 to 400 nm.

5. A method for preparing the aqueous polyurethane-polyurea dispersion according to any one of claims 1-4, characterized in that, include: 1) The components a), b), c), the first solvent and the catalyst are subjected to a first reaction in an inert atmosphere. The temperature of the first reaction is 50-150°C and the time of the first reaction is 3-6 hours to obtain a polyurethane prepolymer. 2) After cooling the polyurethane prepolymer to 35-50°C, add the aqueous solutions of component d), component e), and component f), and carry out a second reaction at 35-50°C for 10-30 minutes to obtain an intermediate material; 3) Add the component g to the intermediate material and carry out the third reaction for 5 to 15 minutes. After the reaction is completed, remove the first solvent to obtain the waterborne polyurethane-polyurea dispersion.

6. The preparation method according to claim 5, characterized in that, The first solvent includes one or more of acetone, methyl isobutyl ketone, butanone, tetrahydrofuran, dioxane, acetonitrile, dipropylene glycol dimethyl ether, and 1-methyl-2-pyrrolidone; And / or, the catalyst comprises one or more of triethylamine, 1,4-diazabicyclo-[2,2,2]octane, dibutyltin oxide, tin dioctanoate, dibutyltin dilaurate, bis-(2-ethylhexanoate)tin, bismuth neodecanoate, and bismuth 2-ethylhexanoate.

7. The preparation method according to claim 5, characterized in that, The pressure of the first reaction is 0-5 MPa, preferably 0-1 MPa.

8. The preparation method according to claim 5, characterized in that, Before step 2), the process includes adding a second solvent to the polyurethane prepolymer for dilution, then cooling the diluted polyurethane prepolymer to 35-50°C, adding an aqueous solution of component d), an aqueous solution of component e), and an aqueous solution of component f), and carrying out a second reaction at 35-50°C for 10-30 minutes to obtain an intermediate material. The mass of the first solvent and the second solvent is 0.8 to 3.0 times the mass of the solids in the aqueous polyurethane-polyurea dispersion, preferably 1.0 to 2.0 times.

9. The preparation method according to claim 5, characterized in that, Before step 3), deionized water is added to the intermediate material for dispersion under stirring, wherein the stirring speed is 800-1500 r / min and the stirring time is 5-15 min; then the component g is added to the dispersed intermediate material for a third reaction for 5-15 min. After the reaction is completed, the solvent is removed to obtain the waterborne polyurethane-polyurea dispersion.

10. The application of a waterborne polyurethane-polyurea dispersion in printing, characterized in that, The aqueous polyurethane-polyurea dispersion includes the aqueous polyurethane-polyurea dispersion according to any one of claims 1-4 or the aqueous polyurethane-polyurea dispersion obtained according to the preparation method according to any one of claims 5-9.

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