High-wear-resistance water-based polyester-polyurethane resin and preparation method thereof

Abstract

The invention provides high-wear-resistance waterborne polyester-polyurethane resin and a preparation method thereof, and relates to the technical field of functional resin synthesis, mixed resin comprises a polyester component containing a long-chain aliphatic group and a polyurethane component containing a siloxane group, and the preparation method comprises the following steps: synthesizing polyester introduced with the long-chain aliphatic group; the preparation method comprises the following steps: synthesizing a siloxane group-introduced polyurethane prepolymer, adding a neutralizing agent into the obtained polyurethane prepolymer to carry out a neutralization reaction, adding a chain extender, continuously stirring to react for a period of time, gradually adding water to carry out high-speed dispersion, and removing a solvent to form the waterborne polyester-polyurethane resin emulsion with introduced long-chain aliphatic groups and siloxane groups. According to the water-based polyester-polyurethane resin provided by the invention, the mechanical property, especially the wear resistance, of a material is improved in all aspects, and the material has certain scratch resistance.

Description

Technical Field

[0001] The invention provides a highly wear-resistant water-based polyester-polyurethane resin and a preparation method thereof, and relates to the technical field of functional resin synthesis. Background Art

[0002] Polyurethane (PU), whose full name is polyurethane, is a polymer compound generated by polymerization reaction of specific chemical raw materials. In the field of coatings, polyurethane coatings are favored for their excellent comprehensive performance. Polyurethane coatings are mainly composed of isocyanates, polyols, solvents, additives and pigments. Among them, isocyanates and polyols are the main raw materials for forming polyurethane resins, which are gradually polymerized to form polyurethane resins with high molecular weight. Solvents are used to adjust the viscosity and construction performance of the coating, while additives are used to improve the fluidity, drying, weather resistance and other properties of the coating. Polyurethane coatings can be divided into many types, including single-component polyurethane coatings and two-component polyurethane coatings. Single-component polyurethane coatings are easy to use, but their performance is relatively limited; two-component polyurethane coatings have more excellent performance, such as high strength, high wear resistance, high weather resistance, etc., and are high-end products among polyurethane coatings. Polyurethane coatings have been widely used in the field of coatings. Polyurethane coatings occupy an important position in automobile coatings. They are used for coating automobile bodies, chassis, parts, etc. to improve the appearance quality and durability of automobiles. In addition, polyurethane coatings can be used for coating the exterior walls, interior walls, ceilings and other parts of buildings, providing excellent decorative effects and protective properties. At the same time, polyurethane coatings perform well in wood coatings and can give wood products excellent gloss and wear resistance. As a leader in the coatings industry, polyurethane coatings are widely used in many fields due to their excellent comprehensive performance. However, although they have shown excellent wear resistance, weather resistance and adhesion, there is still room for improvement in mechanical properties, especially for applications in high stress and high impact environments. In some industrial environments, such as automobile manufacturing and building exterior walls, coatings need to withstand frequent friction and scratches. Although current polyurethane coatings have good wear resistance, their wear resistance and scratch resistance still need to be further enhanced under extreme conditions.

[0003] Chinese patent CN111087572A discloses a method for preparing a bio-based waterborne polyurethane resin with high wear resistance. The solution uses a long-chain compound with a dimer fatty acid main chain to synthesize waterborne polyurethane to reduce the use of petroleum-based compounds and obtain better physical and mechanical properties by improving the compatibility of reactants. However, the technology mainly uses bio-based material reactions and is mainly used in clothing leather surface resins. The performance is mainly reflected by improving flexibility, and the actual wear resistance is not ideal. Chinese patents CN109456690B, CN114350242A, etc. all disclose compositions of waterborne polyurethane resin coatings or emulsions with good wear resistance, but their research and development ideas are to improve the wear resistance of the product by optimizing the filler or emulsion formula and emulsion preparation process, rather than starting from the waterborne polyurethane resin itself. A large amount of research and development work from these perspectives has confirmed that continuing such research can no longer further improve the wear resistance of the product. Summary of the invention

[0004] To solve the above problems, the present invention is characterized in that the specific scheme is as follows:

[0005] A highly wear-resistant water-based polyester-polyurethane resin comprises a polyester component containing a long-chain aliphatic group and a polyurethane component containing a siloxane group.

[0006] Preferably, the long-chain aliphatic group comprises a sebacic acid group or a 1,12-dodecanedioic acid group; wherein the chemical structural formula of the sebacic acid group is: [-(CH2)8-C(O)-OROC(O)-(CH2)8-]-n, wherein R represents a diol group and n represents a repeating unit of a polyester chain; wherein the chemical structural formula of the 1,12-dodecanedio ... 10 -C(O)-OROC(O)-(CH2) 10 -]-n, wherein R represents a diol group and n represents a repeating unit of a polyester chain.

[0007] The present invention also provides a method for preparing the above-mentioned highly wear-resistant water-based polyester-polyurethane resin, comprising the following steps:

[0008] S1. Synthesis of polyester with long-chain aliphatic groups introduced: adding a long-chain dibasic acid and a diol into a reactor, adding a solvent and a catalyst, stirring evenly, heating under nitrogen protection to react, cooling after reaction and discharging to obtain a polyester with long-chain aliphatic groups introduced;

[0009] S2, synthesis of polyurethane prepolymer introduced with siloxane groups: adding the polyester obtained in S1, the diol containing siloxane and the diisocyanate into a reactor, adding a catalyst, heating for reaction, and obtaining a polyurethane prepolymer introduced with siloxane groups after the reaction is completed;

[0010] S3. Cooling the obtained polyurethane prepolymer, adding a neutralizing agent for neutralization reaction, adding a chain extender, continuing to stir and react for a period of time, gradually adding water for high-speed dispersion, heating and distilling to remove the solvent after uniform dispersion, and obtaining an aqueous polyester-polyurethane resin emulsion with introduced long-chain aliphatic groups and siloxane groups.

[0011] Preferably, the long-chain dibasic acid in step S1 includes sebacic acid or 1,12-dodecanedioic acid.

[0012] Preferably, the diol in step S1 includes ethylene glycol or propylene glycol.

[0013] Preferably, the molar ratio of the long-chain dibasic acid to the diol in step S1 is (1.05-1.1):1.

[0014] Preferably, the reaction heating rate in step S1 is 10-20° C. / min, the reaction temperature is 200-205° C., and the reaction time is 3-5 h; until a predetermined acid value (10-30 mg KOH / g) is reached.

[0015] Preferably, the solvent in step S1 is acetone, and the mass of the acetone is 0.8-1.5 times the sum of the mass of the long-chain dibasic acid and the diol.

[0016] Preferably, the catalyst in step S1 is tetrabutyl titanate, and the amount used is 0.3-0.5wt% of the total mass of the reaction system.

[0017] Preferably, the silicone-containing diol in step S2 includes N-β-(aminoethyl)-γ-aminopropyl polydimethylsiloxane or bis(hydroxymethyl)siloxane.

[0018] Preferably, the molar ratio of the polyester to the siloxane-containing diol in step S2 is (0.8-0.9):1.

[0019] Preferably, the catalyst in step S2 includes dibutyltin dilaurate, and the amount of the catalyst is 0.3-0.5wt% of the total mass of the system.

[0020] Preferably, the heating reaction in step S2 is carried out at a temperature of 85-90° C. for 2.5-3.0 h, until the NCO content reaches a predetermined value (5%-7%).

[0021] Preferably, the cooling in step S3 is to 60-65°C, the mass ratio of polyurethane prepolymer, neutralizer and chain extender is (30-40):(2-3):1; the mass ratio of polyurethane prepolymer to water is (2-2.5):1; the dispersion time is 1-1.5h; the heating distillation to remove the solvent has a distillation temperature of 56-60°C.

[0022] Beneficial effects of the present invention:

[0023] The waterborne polyester-polyurethane resin provided by the present invention has high mechanical properties, excellent mechanical properties, and also has scratch resistance (certain self-repairing properties).

[0024] Polyester matrix: obtained by the reaction of long-chain aliphatic dibasic acid (adipic acid) and long-chain diol (polyethylene glycol 1000), which provides flexibility and chemical stability to the matrix.

[0025] Polyurethane part: obtained by the reaction of diisocyanate (MDI) and siloxane-containing diol. The introduction of siloxane groups and the synergistic effect of long-chain aliphatic groups realize the self-healing function of the material.

[0026] The polyester provided by the present invention, which introduces long-chain aliphatic groups, contains an acidic end. Generally speaking, in polyester synthesis, if we want to obtain higher flexibility, we will choose to retain the alcoholic end. In the present invention, retaining the acidic end makes a greater contribution to the scratch resistance (certain self-healing properties) of the material. DETAILED DESCRIPTION

[0027] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0028] Unless otherwise defined, all professional and scientific terms used herein have the same meanings as those familiar to those skilled in the art. In addition, any methods and materials similar or equivalent to those described herein may be applied to the present invention. The preferred implementation methods and materials described herein are for demonstration purposes only and are not intended to limit the content of this application.

[0029] The experimental methods in the following examples are conventional methods unless otherwise specified, and the experimental materials used in the following examples are purchased from commercial channels unless otherwise specified.

[0030] Embodiment Preparation of highly wear-resistant waterborne polyester-polyurethane resin:

[0031] S1. Synthesis of polyester with long-chain aliphatic groups introduced: adding a long-chain dibasic acid and a diol into a reactor, adding a solvent and a catalyst, stirring evenly, heating under nitrogen protection to react, cooling after reaction and discharging to obtain a polyester with long-chain aliphatic groups introduced;

[0032] S2. Synthesis of polyurethane prepolymer with siloxane group introduced: adding the polyester obtained in S1, siloxane-containing diol and diisocyanate into a reactor, adding a catalyst, heating and reacting to obtain a polyurethane prepolymer with siloxane group introduced;

[0033] S3. Cooling the obtained polyurethane prepolymer, adding a neutralizing agent for neutralization reaction, adding a chain extender, continuing to stir and react for a period of time, gradually adding water for high-speed dispersion, heating and distilling to remove the solvent after uniform dispersion, and obtaining an aqueous polyester-polyurethane resin emulsion with introduced long-chain aliphatic groups and siloxane groups.

[0034] The long-chain dibasic acid in step S1 includes sebacic acid or 1,12-dodecanedioic acid.

[0035] The diol in step S1 includes ethylene glycol or propylene glycol.

[0036] The molar ratio of the long-chain dibasic acid to the diol in step S1 is (1.05-1.1):1.

[0037] In step S1, the reaction temperature rise rate is 10-20°C / min, the reaction temperature is 200-205°C, and the reaction time is 3-5h; until the predetermined acid value (10-30mg KOH / g) is reached.

[0038] The catalyst in step S1 is tetrabutyl titanate, and the amount used is 0.3-0.5wt% of the total mass of the reaction system.

[0039] The silicone-containing diol in step S2 includes N-β-(aminoethyl)-γ-aminopropyl polydimethylsiloxane or bis(hydroxymethyl)siloxane.

[0040] The molar ratio of the polyester to the silicone-containing diol in step S2 is (0.8-0.9):1.

[0041] The catalyst in step S2 includes dibutyltin dilaurate, and the amount of the catalyst used is 0.3-0.5wt% of the total mass of the system.

[0042] The heating reaction in step S2 is carried out at a temperature of 85-90° C. for 2.5-3.0 h, until the NCO content reaches a predetermined value (5%-7%).

[0043] The solvent in step S1 is acetone, and the mass of the acetone is 0.8-1.5 times the sum of the mass of the long-chain dibasic acid and the diol.

[0044] The cooling in step S3 is to 60-65°C, the mass ratio of polyurethane prepolymer, neutralizer and chain extender is (30-40):(2-3):1; the mass ratio of polyurethane prepolymer to water is (2-2.5):1; the dispersion time is 1-1.5h; the heating distillation to remove the solvent has a distillation temperature of 56-60°C.

[0045] Example 1 Preparation of highly wear-resistant water-based polyester-polyurethane resin:

[0046] S1. Synthesis of polyester with long-chain aliphatic groups introduced: adding a long-chain dibasic acid and a diol into a reactor, adding a solvent and a catalyst, stirring evenly, heating under nitrogen protection to react, cooling after reaction and discharging to obtain a polyester with long-chain aliphatic groups introduced;

[0047] S2. Synthesis of polyurethane prepolymer with siloxane group introduced: adding the polyester obtained in S1, siloxane-containing diol and diisocyanate into a reactor, adding a catalyst, heating and reacting to obtain a polyurethane prepolymer with siloxane group introduced;

[0048] S3. Cooling the obtained polyurethane prepolymer, adding a neutralizing agent for neutralization reaction, adding a chain extender, continuing to stir and react for a period of time, gradually adding water for high-speed dispersion, heating and distilling to remove the solvent after uniform dispersion, and obtaining an aqueous polyester-polyurethane resin emulsion with introduced long-chain aliphatic groups and siloxane groups.

[0049] The long-chain dibasic acid in step S1 includes sebacic acid.

[0050] The diol in step S1 includes ethylene glycol.

[0051] The molar ratio of the long-chain dibasic acid to the diol in step S1 is 1.05:1.

[0052] The reaction temperature rise rate of step S1 is 10°C / min, the reaction temperature is 200°C, and the reaction time is 3-5h; until the predetermined acid value (10mg KOH / g) is reached.

[0053] The catalyst in step S1 is tetrabutyl titanate, and the amount used is 0.3wt% of the total mass of the reaction system.

[0054] The silicone-containing diol in step S2 includes N-β-(aminoethyl)-γ-aminopropyl polydimethylsiloxane.

[0055] The molar ratio of the polyester to the siloxane-containing diol in step S2 is 0.8:1.

[0056] The catalyst in step S2 includes dibutyltin dilaurate, and the amount of the catalyst used is 0.3wt% of the total mass of the system.

[0057] The heating reaction in step S2 is carried out at a temperature of 85° C. for 2.5-3.0 hours until the NCO content reaches a predetermined value of 5%.

[0058] The solvent in step S1 is acetone, and the mass of acetone is 0.8 times the sum of the mass of the long-chain dibasic acid and the diol.

[0059] The cooling in step S3 is to 60°C, the mass ratio of polyurethane prepolymer, neutralizer and chain extender is 30:2:1; the mass ratio of polyurethane prepolymer to water is 2:1; the dispersion time is 1h; the heating distillation to remove the solvent has a distillation temperature of 56°C.

[0060] Example 2 Preparation of highly wear-resistant water-based polyester-polyurethane resin:

[0061] S1. Synthesis of polyester with long-chain aliphatic groups introduced: adding a long-chain dibasic acid and a diol into a reactor, adding a solvent and a catalyst, stirring evenly, heating under nitrogen protection to react, cooling after reaction and discharging to obtain a polyester with long-chain aliphatic groups introduced;

[0062] S2. Synthesis of polyurethane prepolymer with siloxane group introduced: adding the polyester obtained in S1, siloxane-containing diol and diisocyanate into a reactor, adding a catalyst, heating and reacting to obtain a polyurethane prepolymer with siloxane group introduced;

[0063] S3. Cooling the obtained polyurethane prepolymer, adding a neutralizing agent for neutralization reaction, adding a chain extender, continuing to stir and react for a period of time, gradually adding water for high-speed dispersion, heating and distilling to remove the solvent after uniform dispersion, and obtaining an aqueous polyester-polyurethane resin emulsion with introduced long-chain aliphatic groups and siloxane groups.

[0064] The long-chain dibasic acid in step S1 includes sebacic acid.

[0065] The diol in step S1 includes ethylene glycol.

[0066] The molar ratio of the long-chain dibasic acid to the diol in step S1 is 1.1:1.

[0067] The reaction temperature rise rate of step S1 is 20°C / min, the reaction temperature is 205°C, and the reaction time is 3-5h; until the predetermined acid value (20mg KOH / g) is reached.

[0068] The catalyst in step S1 is tetrabutyl titanate, and the amount used is 0.5wt% of the total mass of the reaction system.

[0069] The siloxane-containing diol in step S2 includes bis(hydroxymethyl)siloxane.

[0070] The molar ratio of the polyester to the siloxane-containing diol in step S2 is 0.9:1.

[0071] The catalyst in step S2 includes dibutyltin dilaurate, and the amount of the catalyst used is 0.5wt% of the total mass of the system.

[0072] The heating reaction in step S2 is carried out at a temperature of 90° C. for 2.5-3.0 hours until the NCO content reaches a predetermined value of 5%.

[0073] The solvent in step S1 is acetone, and the mass of acetone is 1.5 times the sum of the mass of the long-chain dibasic acid and the diol.

[0074] The cooling in step S3 is to 65°C, the mass ratio of polyurethane prepolymer, neutralizer and chain extender is 40:3:1; the mass ratio of polyurethane prepolymer to water is 2.5:1; the dispersion time is 1.5h; the heating distillation to remove the solvent has a distillation temperature of 60°C.

[0075] Example 3 Preparation of highly wear-resistant water-based polyester-polyurethane resin:

[0076] S1. Synthesis of polyester with long-chain aliphatic groups introduced: adding a long-chain dibasic acid and a diol into a reactor, adding a solvent and a catalyst, stirring evenly, heating under nitrogen protection to react, cooling after reaction and discharging to obtain a polyester with long-chain aliphatic groups introduced;

[0077] S2. Synthesis of polyurethane prepolymer with siloxane group introduced: adding the polyester obtained in S1, siloxane-containing diol and diisocyanate into a reactor, adding a catalyst, heating and reacting to obtain a polyurethane prepolymer with siloxane group introduced;

[0078] S3. Cooling the obtained polyurethane prepolymer, adding a neutralizing agent for neutralization reaction, adding a chain extender, continuing to stir and react for a period of time, gradually adding water for high-speed dispersion, heating and distilling to remove the solvent after uniform dispersion, and obtaining an aqueous polyester-polyurethane resin emulsion with introduced long-chain aliphatic groups and siloxane groups.

[0079] The long-chain dibasic acid in step S1 includes 1,12-dodecanedioic acid.

[0080] The diol in step S1 includes propylene glycol.

[0081] The molar ratio of the long-chain dibasic acid to the diol in step S1 is 1.1:1.

[0082] The reaction temperature rise rate of step S1 is 20°C / min, the reaction temperature is 205°C, and the reaction time is 3-5h; until the predetermined acid value of 30mg KOH / g is reached.

[0083] The catalyst in step S1 is tetrabutyl titanate, and the amount used is 0.5wt% of the total mass of the reaction system.

[0084] The silicone-containing diol in step S2 includes N-β-(aminoethyl)-γ-aminopropyl polydimethylsiloxane.

[0085] The molar ratio of the polyester to the siloxane-containing diol in step S2 is 0.8:1.

[0086] The catalyst in step S2 includes dibutyltin dilaurate, and the amount of the catalyst used is 0.3wt% of the total mass of the system.

[0087] The heating reaction in step S2 is carried out at a temperature of 85° C. for 2.5 hours until the NCO content reaches a predetermined value (5%).

[0088] The solvent in step S1 is acetone, and the mass of acetone is 0.8 times the sum of the mass of the long-chain dibasic acid and the diol.

[0089] The cooling in step S3 is to 60°C, the mass ratio of polyurethane prepolymer, neutralizer and chain extender is 35:2:1; the mass ratio of polyurethane prepolymer to water is 2:1; the dispersion time is 1.5h; the heating distillation to remove the solvent has a distillation temperature of 60°C.

[0090] The difference between Comparative Example 1 and Example 3 is that no long-chain aliphatic group is introduced.

[0091] S1. Synthesis of polyester: Add dibasic acid and diol into a reactor, add solvent and catalyst, stir evenly, heat up under nitrogen protection to react, cool down after reaction and discharge to obtain polyester;

[0092] S2. Synthesis of polyurethane prepolymer with siloxane group introduced: adding the polyester obtained in S1, siloxane-containing diol and diisocyanate into a reactor, adding a catalyst, heating and reacting to obtain a polyurethane prepolymer with siloxane group introduced;

[0093] S3. Cooling the obtained polyurethane prepolymer, adding a neutralizing agent for neutralization reaction, adding a chain extender, continuing to stir and react for a period of time, gradually adding water for high-speed dispersion, heating and distilling to remove the solvent after uniform dispersion, and obtaining an aqueous polyester-polyurethane resin emulsion with introduced long-chain aliphatic groups and siloxane groups.

[0094] The dibasic acid in step S1 includes adipic acid.

[0095] The diol in step S1 includes propylene glycol.

[0096] The molar ratio of the long-chain dibasic acid to the diol in step S1 is 1.1:1.

[0097] The reaction temperature rise rate of step S1 is 20°C / min, the reaction temperature is 205°C, and the reaction time is 3-5h; until the predetermined acid value of 30mg KOH / g is reached.

[0098] The catalyst in step S1 is tetrabutyl titanate, and the amount used is 0.5wt% of the total mass of the reaction system.

[0099] The silicone-containing diol in step S2 includes N-β-(aminoethyl)-γ-aminopropyl polydimethylsiloxane.

[0100] The molar ratio of the polyester to the siloxane-containing diol in step S2 is 0.8:1.

[0101] The catalyst in step S2 includes dibutyltin dilaurate, and the amount of the catalyst used is 0.3wt% of the total mass of the system.

[0102] The heating reaction in step S2 is carried out at a temperature of 85° C. for 2.5 hours until the NCO content reaches a predetermined value (5%).

[0103] The solvent in step S1 is acetone, and the mass of acetone is 0.8 times the sum of the mass of the dibasic acid and the diol.

[0104] The cooling in step S3 is to 60°C, the mass ratio of polyurethane prepolymer, neutralizer and chain extender is 35:2:1; the mass ratio of polyurethane prepolymer to water is 2:1; the dispersion time is 1.5h; the heating distillation to remove the solvent has a distillation temperature of 60°C.

[0105] The difference between Comparative Example 2 and Example 3 is that no siloxane group is introduced.

[0106] S1. Synthesis of polyester with long-chain aliphatic groups introduced: adding a long-chain dibasic acid and a diol into a reactor, adding a solvent and a catalyst, stirring evenly, heating under nitrogen protection to react, cooling after reaction and discharging to obtain a polyester with long-chain aliphatic groups introduced;

[0107] S2, synthesis of polyurethane prepolymer: adding the polyester, diol and diisocyanate obtained in S1 into a reactor, adding a catalyst, heating and reacting to obtain a polyurethane prepolymer;

[0108] S3. Cooling the obtained polyurethane prepolymer, adding a neutralizing agent for neutralization reaction, adding a chain extender, continuing to stir and react for a period of time, gradually adding water for high-speed dispersion, heating and distilling to remove the solvent after uniform dispersion, and obtaining an aqueous polyester-polyurethane resin emulsion with introduced long-chain aliphatic groups and siloxane groups.

[0109] The long-chain dibasic acid in step S1 includes 1,12-dodecanedioic acid.

[0110] The diol in step S1 includes propylene glycol.

[0111] The molar ratio of the long-chain dibasic acid to the diol in step S1 is 1.1:1.

[0112] The reaction temperature rise rate of step S1 is 20°C / min, the reaction temperature is 205°C, and the reaction time is 3-5h; until the predetermined acid value of 30mg KOH / g is reached.

[0113] The catalyst in step S1 is tetrabutyl titanate, and the amount used is 0.5wt% of the total mass of the reaction system.

[0114] The diol in step S2 includes 1,4-butanediol.

[0115] The molar ratio of the polyester to the diol in step S2 is 0.8:1.

[0116] The catalyst in step S2 includes dibutyltin dilaurate, and the amount of the catalyst used is 0.3wt% of the total mass of the system.

[0117] The heating reaction in step S2 is carried out at a temperature of 85° C. for 2.5 hours until the NCO content reaches a predetermined value (5%).

[0118] The solvent in step S1 is acetone, and the mass of acetone is 0.8 times the sum of the mass of the long-chain dibasic acid and the diol.

[0119] The cooling in step S3 is to 60°C, the mass ratio of polyurethane prepolymer, neutralizer and chain extender is 35:2:1; the mass ratio of polyurethane prepolymer to water is 2:1; the dispersion time is 1.5h; the heating distillation to remove the solvent has a distillation temperature of 60°C.

[0120] The difference between Comparative Example 3 and Example 3 is that no long-chain aliphatic groups and siloxane groups are introduced.

[0121] S1. Synthesis of polyester: Add dibasic acid and diol into a reactor, add solvent and catalyst, stir evenly, heat up under nitrogen protection to react, cool down after reaction and discharge to obtain polyester;

[0122] S2, synthesis of polyurethane prepolymer: adding the polyester, diol and diisocyanate obtained in S1 into a reactor, adding a catalyst, heating and reacting to obtain a polyurethane prepolymer;

[0123] S3. Cooling the obtained polyurethane prepolymer, adding a neutralizing agent for neutralization reaction, adding a chain extender, continuing to stir and react for a period of time, gradually adding water for high-speed dispersion, heating and distilling to remove the solvent after uniform dispersion, and obtaining an aqueous polyester-polyurethane resin emulsion with introduced long-chain aliphatic groups and siloxane groups.

[0124] The dibasic acid in step S1 includes adipic acid.

[0125] The diol in step S1 includes propylene glycol.

[0126] The molar ratio of the long-chain dibasic acid to the diol in step S1 is 1.1:1.

[0127] The reaction temperature rise rate of step S1 is 20°C / min, the reaction temperature is 205°C, and the reaction time is 3-5h; until the predetermined acid value of 30mg KOH / g is reached.

[0128] The catalyst in step S1 is tetrabutyl titanate, and the amount used is 0.5wt% of the total mass of the reaction system.

[0129] The diol in step S2 includes 1,4-butanediol.

[0130] The molar ratio of the polyester to the siloxane-containing diol in step S2 is 0.8:1.

[0131] The catalyst in step S2 includes dibutyltin dilaurate, and the amount of the catalyst used is 0.3wt% of the total mass of the system.

[0132] The heating reaction in step S2 is carried out at a temperature of 85° C. for 2.5 hours until the NCO content reaches a predetermined value (5%).

[0133] The solvent in step S1 is acetone, and the mass of acetone is 0.8 times the sum of the mass of the dibasic acid and the diol.

[0134] The cooling in step S3 is to 60°C, the mass ratio of polyurethane prepolymer, neutralizer and chain extender is 35:2:1; the mass ratio of polyurethane prepolymer to water is 2:1; the dispersion time is 1.5h; the heating distillation to remove the solvent has a distillation temperature of 60°C.

[0135] The difference between Comparative Example 4 and Example 3 is that the alcohol terminal is retained in the synthesis of the polyester with long-chain aliphatic groups (more diol is used).

[0136] S1. Synthesis of polyester with long-chain aliphatic groups introduced: adding a long-chain dibasic acid and a diol into a reactor, adding a solvent and a catalyst, stirring evenly, heating under nitrogen protection to react, cooling after reaction and discharging to obtain a polyester with long-chain aliphatic groups introduced;

[0137] S2. Synthesis of polyurethane prepolymer with siloxane group introduced: adding the polyester obtained in S1, siloxane-containing diol and diisocyanate into a reactor, adding a catalyst, heating and reacting to obtain a polyurethane prepolymer with siloxane group introduced;

[0138] S3. Cooling the obtained polyurethane prepolymer, adding a neutralizing agent for neutralization reaction, adding a chain extender, continuing to stir and react for a period of time, gradually adding water for high-speed dispersion, heating and distilling to remove the solvent after uniform dispersion, and obtaining an aqueous polyester-polyurethane resin emulsion with introduced long-chain aliphatic groups and siloxane groups.

[0139] The long-chain dibasic acid in step S1 includes 1,12-dodecanedioic acid.

[0140] The diol in step S1 includes propylene glycol.

[0141] The molar ratio of the long-chain dibasic acid to the diol in step S1 is 1:1.1.

[0142] The reaction temperature rise rate of step S1 is 20°C / min, the reaction temperature is 205°C, and the reaction time is 3-5h; until the predetermined acid value of 30mg KOH / g is reached.

[0143] The catalyst in step S1 is tetrabutyl titanate, and the amount used is 0.5wt% of the total mass of the reaction system.

[0144] The silicone-containing diol in step S2 includes N-β-(aminoethyl)-γ-aminopropyl polydimethylsiloxane.

[0145] The molar ratio of the polyester to the siloxane-containing diol in step S2 is 0.8:1.

[0146] The catalyst in step S2 includes dibutyltin dilaurate, and the amount of the catalyst used is 0.3wt% of the total mass of the system.

[0147] The heating reaction in step S2 is carried out at a temperature of 85° C. for 2.5 hours until the NCO content reaches a predetermined value (5%).

[0148] The solvent in step S1 is acetone, and the mass of acetone is 0.8 times the sum of the mass of the long-chain dibasic acid and the diol.

[0149] The cooling in step S3 is to 60°C, the mass ratio of polyurethane prepolymer, neutralizer and chain extender is 35:2:1; the mass ratio of polyurethane prepolymer to water is 2:1; the dispersion time is 1.5h; the heating distillation to remove the solvent has a distillation temperature of 60°C.

[0150] Performance testing:

[0151] The above samples were prepared into coatings according to the following formula:

[0152] Polyester-polyurethane resin emulsion: 60 parts, curing agent (HDI trimer): 5 parts, leveling agent (water-based acrylic leveling agent): 0.5 parts, defoaming agent (silicone water-based defoaming agent): 0.2 parts, thickener (hydroxyethyl cellulose): 0.5 parts, filler (nano calcium carbonate): 10 parts, deionized water: 5 parts.

[0153] Weigh each component according to the formula ratio, add the polyester-polyurethane resin emulsion into the stirring container, add the water-based curing agent and water-based additives (such as leveling agent, defoaming agent, thickener) in turn, stir until uniform, and finally add deionized water to adjust the viscosity of the coating.

[0154] Select a clean and smooth substrate (glass sheet), wipe the surface of the substrate with ethanol and acetone in turn to ensure that there is no oil stain and impurities. Spray the mixed coating evenly on the surface of the substrate. The coating thickness is controlled at 100 microns, and the coating thickness is monitored in real time using a thickness gauge. Put the sample in a constant temperature oven and cure it at 60°C for 2 hours.

[0155] Strength test: GB / T 1040.3-2006 "Determination of tensile properties of plastics Part 3: Test conditions for films and sheets", using an electronic universal testing machine equipped with a standard fixture. Set the tensile speed to 50 mm / min.

[0156] Hardness test: GB / T 6739-2006 "Determination of film hardness of paints and varnishes by pencil method", using a pencil hardness tester and a set of standard hardness pencils, with an inclination angle of 45°.

[0157] Wear resistance test: GB / T 1768-2006 "Determination of abrasion resistance of paints and varnishes - Rotating rubber grinding wheel method", use a wear test machine and a specified rotating rubber grinding wheel for friction test.

[0158] Scratch resistance (certain self-healing properties) test: Use a standardized scratch machine to create scratches on the coating surface. The depth of the scratch should reach the middle layer of the coating to simulate the damage in actual use. Create 3 parallel scratches with a length of 2 cm and a depth of 50 microns. Place the scratched sample under set environmental conditions in a constant temperature box set at 60°C for 24 hours. Scratch healing observation: After taking out the sample, detect and calculate the repair rate (based on the scratch depth):

[0159]

[0160] The three scratch data of each sample were averaged. The results are shown in Table 1.

[0161] Table 1 Sample performance test results

[0162]

[0163] From the above results, it can be seen that the simultaneous presence of long-chain aliphatic groups and siloxane groups can improve the mechanical properties of the product as a whole, especially the wear resistance, and this is also the key factor for the resulting resin to have scratch resistance (certain self-healing properties). Long-chain aliphatic groups provide flexibility and ductility, allowing the material to disperse stress when subjected to stress or damage, while siloxane groups provide low surface energy and dynamic bonding capabilities, allowing the material to restore its structure after dispersing stress. The two complement each other, allowing the material to effectively self-repair after mechanical damage. The long-chain aliphatic groups in the material give the molecular chain a certain fluidity and rearrangement ability after damage, while the siloxane groups, through their dynamic bonding characteristics, enable the material to re-bond at the damaged site, thereby achieving self-repair. Removal of long-chain aliphatic groups: If only the siloxane groups are retained, the material may lose its flexibility and low-temperature fluidity, and cannot effectively disperse and relieve stress, thereby losing its self-healing ability. Removal of siloxane groups: If only long-chain aliphatic groups are retained, although the material still has flexibility and low-temperature fluidity, it lacks the low surface energy and dynamic bonding ability of siloxane and cannot heal itself after damage. When both groups are absent in the product, the material lacks the flexibility, low surface energy and dynamic bonding ability required for self-repair, resulting in its inability to self-repair after mechanical damage.

[0164] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

[0165] The present invention and its implementation methods are described above, which is not restrictive and is only one of the implementation methods of the present invention. The actual application is not limited thereto. In short, if ordinary technicians in the field are inspired by it and do not deviate from the purpose of the invention, they can creatively design methods and embodiments similar to the technical solution, which should all fall within the protection scope of the present invention.

Claims

1. A highly wear-resistant water-based polyester-polyurethane resin, characterized in that: It includes a polyester component containing a long-chain aliphatic group and a polyurethane component containing a siloxane group.

2. The highly wear-resistant water-based polyester-polyurethane resin according to claim 1, characterized in that: The long-chain aliphatic group includes a sebacic acid group or a 1,12-dodecanedioic acid group; wherein the chemical structure of the sebacic acid group is: [-(CH2)8-C(O)-OROC(O)-(CH2)8-]-n, wherein R represents a diol group and n represents a repeating unit of a polyester chain; the chemical structure of the 1,12-dodecanedioic acid group is: [-(CH2)8-C(O)-OROC(O)-(CH2)8-]-n, wherein R represents a diol group and n represents a repeating unit of a polyester chain; 10 -C(O)-OROC(O)-(CH2) 10 -]-n, wherein R represents a diol group and n represents a repeating unit of a polyester chain.

3. A method for preparing the highly wear-resistant water-based polyester-polyurethane resin according to claim 1 or 2, characterized in that: The following steps are involved: S1. Synthesis of polyester with long-chain aliphatic groups introduced: adding a long-chain dibasic acid and a diol into a reactor, adding a solvent and a catalyst, stirring evenly, heating under nitrogen protection to react, cooling after reaction and discharging to obtain a polyester with long-chain aliphatic groups introduced; S2, synthesis of polyurethane prepolymer introduced with siloxane groups: adding the polyester obtained in S1, the diol containing siloxane and the diisocyanate into a reactor, adding a catalyst, heating for reaction, and obtaining a polyurethane prepolymer introduced with siloxane groups after the reaction is completed; S3. Cooling the obtained polyurethane prepolymer, adding a neutralizing agent for neutralization reaction, adding a chain extender, continuing to stir and react for a period of time, gradually adding water for high-speed dispersion, heating and distilling to remove the solvent after uniform dispersion, and obtaining an aqueous polyester-polyurethane resin emulsion with introduced long-chain aliphatic groups and siloxane groups.

4. The method for preparing a highly wear-resistant water-based polyester-polyurethane resin according to claim 3, characterized in that: The long-chain dibasic acid in step S1 includes sebacic acid or 1,12-dodecanedioic acid; the diol in step S1 includes ethylene glycol or propylene glycol.

5. The method for preparing a highly wear-resistant water-based polyester-polyurethane resin according to claim 3, characterized in that: The molar ratio of the long-chain dibasic acid to the diol in step S1 is (1.05-1.1):1; the solvent in step S1 is acetone, and the mass of acetone is 0.8-1.5 times the sum of the mass of the long-chain dibasic acid and the diol; the catalyst in step S1 is tetrabutyl titanate, and the amount used is 0.3-0.5wt% of the total mass of the reaction system.

6. The method for preparing a highly wear-resistant water-based polyester-polyurethane resin according to claim 3, characterized in that: The reaction heating rate of step S1 is 10-20°C / min, the reaction temperature is 200-205°C, and the reaction time is 3-5h.

7. The method for preparing a highly wear-resistant water-based polyester-polyurethane resin according to claim 3, characterized in that: The silicone-containing diol in step S2 includes N-β-(aminoethyl)-γ-aminopropyl polydimethylsiloxane or bis(hydroxymethyl)siloxane (Bis(hydroxymethyl)siloxane); the molar ratio of the polyester in step S2 to the silicone-containing diol is (0.8-0.9):

1.

8. The method for preparing a highly wear-resistant water-based polyester-polyurethane resin according to claim 3, characterized in that: The catalyst in step S2 includes dibutyltin dilaurate, and the amount of the catalyst used is 0.3-0.5wt% of the total mass of the system.

9. The method for preparing a highly wear-resistant water-based polyester-polyurethane resin according to claim 3, characterized in that: The heating reaction in step S2 is carried out at a temperature of 85-90° C. for 2.5-3.0 h, until the NCO content reaches a predetermined value (5%-7%).

10. The method for preparing a highly wear-resistant water-based polyester-polyurethane resin according to claim 3, characterized in that: The cooling in step S3 is to 60-65°C, the mass ratio of polyurethane prepolymer, neutralizer and chain extender is (30-40):(2-3):1; the mass ratio of polyurethane prepolymer to water is (2-2.5):1; the dispersion time is 1-1.5h; the heating distillation to remove the solvent has a distillation temperature of 56-60°C.

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