Matt waterborne polyurethane and preparation method thereof
By introducing different soft segments to form microphase separation through a specific ratio of isocyanate-terminated polyurethane prepolymers A and B, the problem of poor water resistance and abrasion resistance of matte waterborne polyurethane is solved, achieving a matte effect and improved performance without matting agents.
Patent Information
- Application Number
- CN202511919607.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-18
- Publication Date
- 2026-02-10
AI Technical Summary
Existing matte waterborne polyurethanes suffer from poor water resistance and abrasion resistance after the introduction of matting agents, and the poor interfacial compatibility between the matting agents and the polyurethane matrix makes the coating easy to peel off during friction.
Using isocyanate-terminated polyurethane prepolymer A and isocyanate-terminated polyurethane prepolymer B in specific ratios, microphase separation is formed by introducing diol hydroxyl-terminated polydimethylsiloxane, long-chain alkyl diol and polytetrahydrofuran ether diol with different soft segments, resulting in a rough surface structure and a matte effect. Water resistance and wear resistance are improved by controlling the component ratio.
A matte finish can be achieved without the addition of additional matting agents, significantly improving the water resistance, abrasion resistance, and storage stability of waterborne polyurethane.
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Abstract
Description
Technical Field
[0001] This application relates to the field of waterborne resins, and in particular to a matte waterborne polyurethane and its preparation method. Background Technology
[0002] Currently, most matte waterborne polyurethane preparations in the industry reduce surface gloss by adding matting agents such as silica and talc. While these agents achieve a matte finish, they suffer from poor dispersibility. On one hand, these defects weaken the coating's density, significantly reducing its water resistance and making it prone to blistering and peeling in humid environments. On the other hand, the poor interfacial compatibility between the matting agent particles and the polyurethane matrix leads to easy detachment during friction, resulting in a significant decrease in the coating's abrasion resistance. Therefore, developing a matte waterborne polyurethane that requires no matting agents and possesses excellent water and abrasion resistance is of significant research importance. Summary of the Invention
[0003] To address the temperature difference in water resistance and abrasion resistance caused by the introduction of matting agents in existing matte waterborne polyurethanes, this application provides a matte waterborne polyurethane and its preparation method.
[0004] Firstly, the matte waterborne polyurethane provided in this application adopts the following technical solution: A matte waterborne polyurethane comprises 18.2-25.4 parts by weight of isocyanate-terminated polyurethane prepolymer A, 9.5-14.8 parts by weight of isocyanate-terminated polyurethane prepolymer B, 10-15 parts by weight of polymeric polyol, 0.05-0.1 parts by weight of neutralizer, 0.2-0.25 parts by weight of hydrophilic chain extender, 0.001-0.0015 parts by weight of catalyst, 30-40 parts by weight of diluent, and 100 parts by weight of waterborne dispersant; The isocyanate-terminated polyurethane prepolymer A is obtained by reacting a first isocyanate component, a diol hydroxyl-terminated polydimethylsiloxane, a long-chain alkyl diol, and a polytetrahydrofuran ether diol; the isocyanate-terminated polyurethane prepolymer B is obtained by reacting a second isocyanate component and polypropylene glycol.
[0005] In this application, isocyanate-terminated polyurethane prepolymer A introduces soft segments through a specific ratio of diol hydroxyl-terminated polydimethylsiloxane, long-chain alkyl diol, and polytetrahydrofuran ether diol. Isocyanate-terminated polyurethane prepolymer B introduces soft segments through polypropylene glycol. The matte waterborne polyurethane is obtained by reacting two isocyanate-terminated polyurethane prepolymers containing different soft segments with polymeric polyols, hydrophilic chain extenders, etc. Due to the polarity difference between the hard segments and the organosiloxane and long-chain alkyl segments in the waterborne polyurethane of this application, coupled with the coexistence of different soft segments, the waterborne polyurethane easily undergoes microphase separation, resulting in a rough surface structure after drying and directly exhibiting a matte effect without the need for additional silica as a matting agent. Furthermore, by combining isocyanate-terminated polyurethane prepolymer A and isocyanate-terminated polyurethane prepolymer B and rationally controlling the ratio of the above components, this application facilitates the acquisition of waterborne polyurethane that is both water-resistant and wear-resistant.
[0006] In some specific embodiments, in the isocyanate-terminated polyurethane prepolymer A, the molar ratio of isocyanate in the first isocyanate component, hydroxyl in alcohol-hydroxyl-terminated polydimethylsiloxane, hydroxyl in long-chain alkyl diol, and hydroxyl in polymeric polyol is 1:(0.15-0.2):(0.15-0.2):(0.45-0.5).
[0007] In this application, the molar ratio of each component in isocyanate-terminated polyurethane prepolymer A is controlled within the above-mentioned range, which is beneficial to the formation of a rough surface structure after the waterborne polyurethane dries, and can further improve the water resistance and wear resistance of the waterborne polyurethane, while also improving the storage stability of the waterborne polyurethane.
[0008] In some specific embodiments, the long-chain alkyl diol has the general structural formula HOR1OH, wherein R1 is selected from C15-C20 alkylene groups.
[0009] In some specific embodiments, the number-average molecular weight of the diol hydroxyl-terminated polydimethylsiloxane is 15,000-20,000 g / mol.
[0010] In this application, a diol hydroxyl-terminated polydimethylsiloxane with a number average molecular weight of 15,000-20,000 g / mol is preferred, which can further improve the storage stability of waterborne polyurethane while obtaining matte, water-resistant, and abrasion-resistant waterborne polyurethane.
[0011] In some specific embodiments, the number-average molecular weight of the polytetrahydrofuran ether diol is 1500-2500 g / mol.
[0012] In some specific embodiments, in the isocyanate-terminated polyurethane prepolymer B, the molar ratio of isocyanate in the second isocyanate component to hydroxyl in polypropylene glycol is 1:(0.85-0.9).
[0013] In some specific embodiments, the number-average molecular weight of the polypropylene glycol is 2000-3000 g / mol.
[0014] In some specific embodiments, the polymeric polyol is at least one of polytetrahydrofuran ether diol, polypropylene glycol, polycarbonate diol, and polycaprolactone diol.
[0015] In some specific embodiments, the number-average molecular weight of the polymeric polyol is 1000-3000 g / mol.
[0016] In some specific embodiments, the neutralizing agent is triethylamine.
[0017] In some specific embodiments, the hydrophilic chain extender is at least one of dimethylolpropionic acid and dimethylolbutyric acid.
[0018] Secondly, the preparation method of matte waterborne polyurethane provided in this application adopts the following technical solution: A method for preparing matte waterborne polyurethane includes the following steps: Isocyanate-terminated polyurethane prepolymer A, isocyanate-terminated polyurethane prepolymer B, and catalyst are added to the dehydrated polymerized polyol. The mixture is heated to 75-90℃ and reacted for 2-3 hours. Then, a diluent and a hydrophilic chain extender are added, and the reaction continues at 75-90℃ for 0.8-1.2 hours. The mixture is then cooled to 40℃, a neutralizing agent is added, and the reaction proceeds. Finally, water is added, and the mixture is stirred and dispersed evenly. The diluent is removed under vacuum to obtain matte waterborne polyurethane.
[0019] This application uses the above method to prepare matte waterborne polyurethane, which has the advantages of simple steps and convenient operation.
[0020] In summary, this application includes at least the following beneficial technical effects: (1) In this application, isocyanate-terminated polyurethane prepolymer A introduces soft segments through a specific ratio of diol hydroxyl-terminated polydimethylsiloxane, long-chain alkyl diol, and polytetrahydrofuran ether diol. Isocyanate-terminated polyurethane prepolymer B introduces soft segments through polypropylene glycol. The matte waterborne polyurethane is obtained by reacting two isocyanate-terminated polyurethane prepolymers containing different soft segments with polymeric polyols, hydrophilic chain extenders, etc. In this application, due to the polarity difference between the hard segments and the organosiloxane segments and long-chain alkyl segments in the waterborne polyurethane, coupled with the coexistence of different soft segments, the waterborne polyurethane is prone to microphase separation, resulting in a rough surface structure after drying, directly presenting a matte effect without the need to add silica as a matting agent. In addition, this application, through the combination of isocyanate-terminated polyurethane prepolymer A and isocyanate-terminated polyurethane prepolymer B, and by reasonably controlling the ratio of the above components, is beneficial to obtaining a waterborne polyurethane that is both water-resistant and wear-resistant.
[0021] (2) In this application, the molar ratio of each component in the isocyanate-terminated polyurethane prepolymer A is controlled within the above range, which is beneficial to the formation of a rough surface structure after the waterborne polyurethane is dried, and can further improve the water resistance and wear resistance of the waterborne polyurethane, while also improving the storage stability of the waterborne polyurethane. Detailed Implementation
[0022] The following section provides further explanation of this application in conjunction with specific experiments.
[0023] Preparation Example
Preparation Example 1-1
[0024]
Preparation Examples 1-2
[0025]
Preparation Examples 1-3
[0026]
Preparation Examples 1-4
[0027]
Preparation Examples 1-5
[0028]
Preparation Example 2-1
[0029]
Preparation Example 2-2
[0030]
Example 1
[0031] In this embodiment, the preparation method of matte waterborne polyurethane includes the following steps: Isocyanate-terminated polyurethane prepolymer A, isocyanate-terminated polyurethane prepolymer B, and dibutyltin dilaurate were added to the dehydrated polymerized polyol. The mixture was heated to 75°C and reacted for 3 hours. Then, acetone and dimethylolbutyric acid were added, and the reaction was continued at 75°C for 1.2 hours. The mixture was then cooled to 40°C, and triethylamine was added to react. Finally, water was added, and the mixture was stirred and dispersed evenly. Acetone was removed under vacuum to obtain matte waterborne polyurethane.
[0032]
Example 2
[0033] In this embodiment, the preparation method of matte waterborne polyurethane includes the following steps: Isocyanate-terminated polyurethane prepolymer A, isocyanate-terminated polyurethane prepolymer B, and dibutyltin dilaurate were added to the dehydrated polymerized polyol. The mixture was heated to 90°C and reacted for 2 hours. Then, acetone and dimethylolbutyric acid were added, and the reaction was continued at 90°C for 0.8 hours. The mixture was then cooled to 40°C, and triethylamine was added to react. Finally, water was added, and the mixture was stirred and dispersed evenly. Acetone was removed under vacuum to obtain matte waterborne polyurethane.
[0034]
Example 3
[0035]
Example 4
[0036] Comparative Example Comparative Example 1 A waterborne polyurethane differs from [Example 1] in that: isocyanate-terminated polyurethane prepolymer A is replaced by an equal mass of isocyanate-terminated polyurethane prepolymer A prepared in [Preparation Examples 1-4].
[0037] Comparative Example 2 A waterborne polyurethane differs from [Example 1] in that: isocyanate-terminated polyurethane prepolymer A is replaced by an equal mass of isocyanate-terminated polyurethane prepolymer A prepared in [Preparation Examples 1-5].
[0038] Comparative Example 3 A waterborne polyurethane differs from [Example 1] in that isocyanate-terminated polyurethane prepolymer A is replaced by an equal mass of isocyanate-terminated polyurethane prepolymer B.
[0039] Comparative Example 4 A waterborne polyurethane differs from [Example 1] in that isocyanate-terminated polyurethane prepolymer B is replaced by an equal mass of isocyanate-terminated polyurethane prepolymer A.
[0040] Performance testing Sample preparation: In accordance with GB / T1727-2021 "General method for preparation of coating film", matte waterborne polyurethane was coated on a clean glass surface with a coating thickness of 30μm. Then, it was baked in an oven at 110℃ for 1min. After being completely dried, it was cooled to room temperature for use.
[0041] 1. Gloss: Compliant with ISO / 2813 standard, using glass as the substrate for the coating, and employing German... The Erichsen 500MC gloss meter measures the 60° gloss of a coating.
[0042] (2) Water resistance: The water resistance of samples made of different water-based polyurethanes was tested according to the immersion test method in GB / T 1733-1993 "Test Method for Water Resistance of Coating Film". The water temperature was 25℃ and the immersion time was 72h. The bubbling or peeling of the samples was observed.
[0043] (3) Abrasion resistance: The abrasion resistance of samples made of different water-based polyurethanes was determined in accordance with GB / T1768-2006 "Determination of abrasion resistance of paints and varnishes by rotating rubber grinding wheel method". The coating load was 1 kg, and the rotation was 500 times. The abrasion amount was recorded.
[0044] (4) Stability of waterborne polyurethane: Centrifugal sedimentation test was conducted on waterborne polyurethanes prepared in different examples and comparative examples at room temperature. The centrifuge was centrifuged at 3000 r / min for 15 min, and the presence or absence of precipitation in the emulsion was observed.
[0045] Table 1
[0046] Based on Example 1 and Comparative Examples 1-2, and the test data in Table 1, it can be seen that the coexistence of diol hydroxyl-terminated polydimethylsiloxane and long-chain alkyl diols in the isocyanate-terminated polyurethane prepolymer A in a specific ratio is beneficial to improving the water resistance and abrasion resistance of matte waterborne polyurethane. At the same time, it can also improve the stability of matte waterborne polyurethane to a certain extent.
[0047] Based on Example 1 and Comparative Examples 3-4, and the test data in Table 1, it can be seen that the combination of isocyanate-terminated polyurethane prepolymer A and isocyanate-terminated polyurethane prepolymer B in this application is beneficial to further improve the matte properties of waterborne polyurethane, and at the same time, it is also beneficial to obtain waterborne polyurethane with both water resistance and abrasion resistance.
[0048] Combining Examples 1 and 3-4 with the test data in Table 1, it can be seen that controlling the molar ratio of isocyanate in the first isocyanate component, hydroxyl in alcohol-hydroxyl-terminated polydimethylsiloxane, hydroxyl in long-chain alkyl diol, and hydroxyl in polymeric polyol in the isocyanate-terminated polyurethane prepolymer A within the range of 1:(0.15-0.2):(0.15-0.2):(0.45-0.5) is beneficial for obtaining matte waterborne polyurethane, and can further improve the water resistance and abrasion resistance of waterborne polyurethane, while also improving the storage stability of waterborne polyurethane.
[0049] This specific embodiment is merely an explanation of this application and is not intended to limit it. After reading this specification, those skilled in the art can make modifications to this specific embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they fall within the scope of the claims of this application.
Claims
1. A matte waterborne polyurethane, characterized in that: It includes 18.2-25.4 parts by weight of isocyanate-terminated polyurethane prepolymer A, 9.5-14.8 parts by weight of isocyanate-terminated polyurethane prepolymer B, 10-15 parts by weight of polymeric polyol, 0.05-0.1 parts by weight of neutralizer, 0.2-0.25 parts by weight of hydrophilic chain extender, 0.001-0.0015 parts by weight of catalyst, 30-40 parts by weight of diluent, and 100 parts by weight of aqueous dispersant; The isocyanate-terminated polyurethane prepolymer A is obtained by reacting a first isocyanate component, a diol hydroxyl-terminated polydimethylsiloxane, a long-chain alkyl diol, and a polytetrahydrofuran ether diol; the isocyanate-terminated polyurethane prepolymer B is obtained by reacting a second isocyanate component and polypropylene glycol.
2. The matte waterborne polyurethane according to claim 1, characterized in that: The molar ratio of isocyanate, hydroxyl group in alcohol-hydroxyl-terminated polydimethylsiloxane, hydroxyl group in long-chain alkyl diol, and hydroxyl group in polymeric polyol in the first isocyanate component is 1:(0.15-0.2):(0.15-0.2):(0.45-0.5).
3. A matte waterborne polyurethane according to claim 1 or 2, characterized in that: The long-chain alkyl diol has the general structural formula HOR1OH, where R1 is selected from C15-C20 alkylene groups.
4. A matte waterborne polyurethane according to claim 1 or 2, characterized in that: The number-average molecular weight of the diol hydroxyl-terminated polydimethylsiloxane is 15,000-20,000 g / mol.
5. A matte waterborne polyurethane according to claim 1 or 2, characterized in that: The number-average molecular weight of the polytetrahydrofuran ether diol is 1500-2500 g / mol.
6. The matte waterborne polyurethane according to claim 1, characterized in that: The molar ratio of isocyanate to hydroxyl groups in the second isocyanate component is 1:(0.85-0.9).
7. A matte waterborne polyurethane according to claim 6, characterized in that: The number-average molecular weight of the polypropylene glycol is 2000-3000 g / mol.
8. The matte waterborne polyurethane according to claim 1, characterized in that: The polymerized polyol is at least one of polytetrahydrofuran ether diol, polypropylene glycol, polycarbonate diol, and polycaprolactone diol.
9. A matte waterborne polyurethane according to claim 8, characterized in that: The number average molecular weight of the polymeric polyol is 1000-3000 g / mol.
10. A method for preparing a matte waterborne polyurethane as described in any one of claims 1-9, characterized in that, Includes the following steps: Isocyanate-terminated polyurethane prepolymer A, isocyanate-terminated polyurethane prepolymer B, and catalyst are added to the dehydrated polymerized polyol. The mixture is heated to 75-90℃ and reacted for 2-3 hours. Then, a diluent and a hydrophilic chain extender are added, and the reaction continues at 75-90℃ for 0.8-1.2 hours. The mixture is then cooled to 40℃, a neutralizing agent is added, and the reaction proceeds. Finally, water is added, and the mixture is stirred and dispersed evenly. The diluent is removed under vacuum to obtain matte waterborne polyurethane.