A silane-modified polyurethane acrylate resin, a method for preparing the same, and a coating material

Abstract

This invention relates to the field of coating technology, specifically to a silane-modified polyurethane acrylate resin, its preparation method, and an anti-corrosion coating. The silane-modified polyurethane acrylate resin, by weight, comprises the following components: 25-45 parts polyether polyol, 10-20 parts first plasticizer, 3-6 parts isocyanate, 0.002-0.005 parts inhibitor, 5-15 parts first end-capping agent, 6-18 parts second end-capping agent, 0.002-0.005 parts resin catalyst, and 0.5-2 parts photoinitiator; wherein the first end-capping agent includes pentaerythritol triacrylate and / or polydipentaerythritol pentaacrylate; and the second end-capping agent includes trimethoxysilane and / or triethoxysilane. It can achieve both light curing and rapid moisture curing, and when used in anti-corrosion coatings, it provides characteristics such as fast curing speed, good anti-corrosion effect, high strength, and good flexibility, enabling long-term resistance to the impact of sea waves.

Description

Technical Field

[0001] This invention relates to the field of coating technology, and more specifically, to a silane-modified polyurethane acrylate resin, its preparation method, and an anti-corrosion coating. Background Technology

[0002] The unique characteristic of marine corrosion lies in the fact that it is a result of multiple coupled factors: chloride ion penetration in salt spray, mechanical impact of ocean waves, and the cell effect of oxygen concentration difference during alternating wet and dry conditions. When these factors act alone, the corrosion rate may be 2 to 3 times that of land, and when combined, it can be more than 10 times faster.

[0003] Marine engineering projects often involve construction scenarios requiring emergency repairs to be completed within 2-4 hours. For example, the work window for repairing circumferential welds on offshore wind turbine foundations is limited to 2 hours before and after low tide; repairing damage to the foundation of a cross-sea bridge requires work in the splash zone, with less than 3 hours of work time per day; and repairing welds on the guide walls of tidal power stations must be carried out during low tide, with each repair lasting no more than 3 hours. After construction, some welds or bolt connections require anti-corrosion treatment. This necessitates anti-corrosion materials that are quick to apply, cure rapidly (to prevent erosion by waves), have good anti-corrosion effects, high bonding strength, and can withstand long-term wave impact.

[0004] In view of this, the present invention is hereby proposed. Summary of the Invention

[0005] The primary objective of this invention is to provide a silane-modified polyurethane acrylate resin, which simultaneously contains uncapped acrylate double bonds and siloxane groups at the ends. This resin can achieve photocuring, imparting high hardness and high strength to the material, while also enabling rapid moisture curing to form a dense Si-O-Si network, resulting in strong weather resistance and corrosion resistance.

[0006] A second objective of this invention is to provide a method for preparing the silane-modified polyurethane acrylate resin as described above.

[0007] A third objective of the present invention is to provide an anti-corrosion coating comprising the silane-modified polyurethane acrylate resin as described above.

[0008] In order to achieve the above-mentioned objectives of the present invention, the following technical solution is adopted:

[0009] A silane-modified polyurethane acrylate resin, comprising the following components by weight:

[0010] 25-45 parts of polyether polyol, 10-20 parts of first plasticizer, 3-6 parts of isocyanate, 0.002-0.005 parts of inhibitor, 5-15 parts of first end-capping agent, 6-18 parts of second end-capping agent, 0.002-0.005 parts of resin catalyst, and 0.5-2 parts of photoinitiator;

[0011] The first end-capping agent comprises pentaerythritol triacrylate and / or polydipentaerythritol pentaacrylate; the second end-capping agent comprises trimethoxysilane and / or triethoxysilane.

[0012] The preparation method of the silane-modified polyurethane acrylate resin described in the foregoing embodiments includes the following steps:

[0013] S1. Mix the polyether polyol and the first plasticizer and then dehydrate them under vacuum;

[0014] S2. Add isocyanate and carry out the first reaction under vacuum or inert gas protection to obtain NCO-terminated polyurethane prepolymer;

[0015] S3. After adding the inhibitor and mixing, add the first capping agent and carry out the second reaction under vacuum or inert gas protection to cap all NCO groups;

[0016] S4. Add the second capping agent and resin catalyst, and carry out the third reaction under vacuum or inert gas protection to partially cap the first capping agent;

[0017] S5. Add a photoinitiator and mix under vacuum to obtain the silane-modified polyurethane acrylate resin.

[0018] An anti-corrosion coating comprising the silane-modified polyurethane acrylate resin described in any of the foregoing embodiments.

[0019] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0020] This invention uses pentaerythritol triacrylate and / or polydipentaerythritol pentaacrylate as the first end-capping agent to completely end the NCO groups of the polyurethane prepolymer, and uses trimethoxysilane and / or triethoxysilane as the second end-capping agent to partially end the first end-capping agent. During the synthesis process, a star-shaped structure centered on pentaerythritol triacrylate or polydipentaerythritol pentaacrylate is formed, with its multi-branched structure connected to siloxanes, achieving multi-terminal silane functionalization. This allows for rapid moisture curing, forming a dense Si-O-Si network with high crosslinking density, high cohesive strength, and better weather resistance. Simultaneously, the unenden groups within the resin... Acrylic double bonds undergo free radical polymerization under a suitable UV light source, achieving photocuring. This process rapidly forms a rigid molecular network within 10-20 seconds, effectively resisting the initial impact of seawater erosion. Photocuring causes the acrylate groups to crosslink through C-C bonds, imparting high hardness and strength to the material. Furthermore, during the subsequent hydrolysis and curing process, the siloxane bonds adjacent to the acrylate bonds form a network structure with flexible segments interspersed among the rigid segments, contributing to improved flexibility and corrosion resistance. When used to prepare anti-corrosion coatings, these coatings exhibit characteristics such as fast curing speed, good anti-corrosion effect, high strength, and good flexibility, enabling long-term resistance to the impact of sea waves. Detailed Implementation

[0021] The technical solution of the present invention will be clearly and completely described below with reference to specific embodiments. However, those skilled in the art will understand that the embodiments described below are some embodiments of the present invention, but not all embodiments, and are only used to illustrate the present invention, and should not be regarded as limiting 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. Where specific conditions are not specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall be followed. Where the manufacturers of reagents or instruments are not specified, they are all conventional products that can be purchased commercially.

[0022] A first aspect of the present invention provides a silane-modified polyurethane acrylate resin, wherein the raw materials comprise the following components by weight:

[0023] 25-45 parts of polyether polyol, 10-20 parts of first plasticizer, 3-6 parts of isocyanate, 0.002-0.005 parts of inhibitor, 5-15 parts of first end-capping agent, 6-18 parts of second end-capping agent, 0.002-0.005 parts of resin catalyst, and 0.5-2 parts of photoinitiator;

[0024] The first end-capping agent includes pentaerythritol triacrylate and / or polydipentaerythritol pentaacrylate; the second end-capping agent includes trimethoxysilane and / or triethoxysilane.

[0025] The silane-modified polyurethane acrylate resin provided by this invention uses pentaerythritol triacrylate and / or polydipentaerythritol pentaacrylate as the first end-capping agent to end the NCO groups and form a multi-branched structure. Trimethoxysilane and / or triethoxysilane are used as the second end-capping agent to partially end the first end-capping agent. The ends simultaneously contain unenden acrylate double bonds and siloxane groups, and the multi-branched structure is connected to siloxanes, achieving multi-terminal silane functionalization. It can be photocured and rapidly formed within 10-20 seconds. The rigid molecular network effectively resists the initial impact of seawater erosion, while endowing the material with high hardness and strength. It can also quickly cure in moisture, forming a dense Si-O-Si network with high cross-linking density, high cohesive strength, and better weather resistance. Furthermore, during the later hydrolysis and curing process, the siloxane bonds form a network structure in which flexible segments are interspersed between rigid segments, which helps to improve the material's flexibility and corrosion resistance. When used in anti-corrosion coatings, it can give the material the characteristics of fast curing speed, good anti-corrosion effect, high strength, and good flexibility, and can resist the impact of sea waves for a long time.

[0026] In some embodiments, typically but not limitingly, for example, the mass fraction of the polyether polyol can be any one value or a range of any two values ​​from 25 parts, 30 parts, 35 parts, 40 parts, and 45 parts; the mass fraction of the first plasticizer can be any one value or a range of any two values ​​from 10 parts, 12 parts, 15 parts, 18 parts, and 20 parts; the mass fraction of the isocyanate can be any one value or a range of any two values ​​from 3 parts, 4 parts, 5 parts, and 6 parts; and the mass fraction of the first capping agent can be any one value or a range of any two values ​​from 5 parts, 8 parts, 10 parts, 12 parts, and 15 parts. The mass fraction of the inhibitor can be any one value or a range of any two values ​​from 0.002 parts, 0.003 parts, 0.004 parts, and 0.005 parts; the mass fraction of the second capping agent can be any one value or a range of any two values ​​from 6 parts, 8 parts, 10 parts, 12 parts, 15 parts, and 18 parts; the mass fraction of the resin catalyst can be any one value or a range of any two values ​​from 0.002 parts, 0.003 parts, 0.004 parts, and 0.005 parts; and the mass fraction of the photoinitiator can be any one value or a range of any two values ​​from 0.5 parts, 1 part, 1.5 parts, and 2 parts.

[0027] In some specific embodiments of the present invention, the second capping agent is trimethoxysilane, with a mass fraction of 6-14 parts, for example, any single value or a range of any two values ​​selected from 6, 8, 10, 12, and 14 parts; or, the second capping agent is triethoxysilane, with a mass fraction of 8-18 parts, for example, any single value or a range of any two values ​​selected from 8, 10, 12, 14, 16, and 18 parts. The degree of capping by the first capping agent affects the ratio of photocuring to moisture curing, and thus affects product performance. By controlling the amount of the second capping agent within the above-mentioned range, the first capping agent can achieve a suitable capping rate, achieving rapid curing while obtaining better mechanical properties, flexibility, weather resistance, and salt spray resistance.

[0028] In some specific embodiments of the present invention, the number average molecular weight of the polyether polyol is 2800-4200 g / mol and the functionality is 2. When polyether polyols with a functionality of 2 are selected, a chain structure can be formed during the preparation of polyurethane prepolymers, which can improve the flexibility of the material.

[0029] In some specific embodiments of the present invention, the polyether polyol includes at least one of ED-28, LHE-3000D, and LHE-4000D.

[0030] In some specific embodiments of the present invention, the isocyanate includes at least one of IPDI (isophorone diisocyanate), HDI (hexamethylene diisocyanate), and HMDI (dicyclohexylmethane diisocyanate).

[0031] In some specific embodiments of the present invention, the first plasticizer includes environmentally friendly plasticizer T60 and / or bio-based environmentally friendly plasticizer SK50 produced by Jiangsu Shengkai Plasticizer Technology Co., Ltd.

[0032] In some specific embodiments of the present invention, the inhibitors include TEMPO (2,2,6,6-tetramethylpiperidine oxide) and / or BHT (2,6-di-tert-butyl-p-cresol).

[0033] In some specific embodiments of the present invention, the resin catalyst includes at least one of KP23 (Shanghai Neutron Star Chemical Technology Co., Ltd.), Castel platinum catalyst (Shanghai Neutron Star Chemical Technology Co., Ltd.), and PT-5000 platinum catalyst (Guangzhou Silicon Friends New Materials Technology Co., Ltd.), for catalyzing the reaction between the second end-capping agent and the first end-capping agent.

[0034] In some specific embodiments of the present invention, the photoinitiator includes (2,4,6-trimethylbenzoyl)diphenylphosphine oxide (TPO) and / or 2-hydroxy-2-methyl-1-phenyl-1-propanone (1173).

[0035] A second aspect of the present invention provides a method for preparing the silane-modified polyurethane acrylate resin described in any of the foregoing embodiments, comprising the following steps:

[0036] S1. Mix the polyether polyol and the first plasticizer and then dehydrate them under vacuum;

[0037] S2. Add isocyanate and carry out the first reaction under vacuum or inert gas protection to obtain NCO-terminated polyurethane prepolymer;

[0038] S3. After adding the inhibitor and mixing, add the first capping agent and carry out the second reaction under vacuum or inert gas protection to cap all NCO groups;

[0039] S4. Add the second end-capping agent and resin catalyst, and carry out the third reaction under vacuum or inert gas protection to partially end the first end-capping agent;

[0040] S5. Add a photoinitiator and mix under vacuum to obtain silane-modified polyurethane acrylate resin.

[0041] The method of this invention forms a star-shaped structure centered on pentaerythritol triacrylate or polydipentaerythritol pentaacrylate during polymerization. Its multi-branched structure is connected to siloxanes, realizing multi-terminal silane functionalization. It can be rapidly cured by moisture to form a dense Si-O-Si network with high crosslinking density, high cohesive strength, and stronger weather resistance. The resin contains uncapped acrylates, which can be photocured under a suitable UV light source. It can quickly form a rigid molecular network within 10-20 seconds, which can effectively resist the impact of initial seawater erosion.

[0042] In some specific embodiments of the present invention, in step S1, the temperature of vacuum dehydration is 110-120°C, for example, it can be any one value or a range of any two values ​​among 110°C, 112°C, 115°C, 118°C, and 120°C; the time of vacuum dehydration is 2-3 hours, for example, it can be any one value or a range of any two values ​​among 2 hours, 2.2 hours, 2.5 hours, 2.8 hours, and 3 hours.

[0043] In some specific embodiments of the present invention, in step S2, the reaction temperature of the first reaction is 75-80°C, for example, it can be any one value or a range of any two values ​​among 75°C, 76°C, 78°C, and 80°C; the reaction time is 2.5-3h, for example, it can be any one value or a range of any two values ​​among 2.5h, 2.6h, 2.8h, and 3h.

[0044] In some specific embodiments of the present invention, the reaction temperature of the second reaction is 75-80°C, for example, it can be any one value or a range of any two values ​​among 75°C, 76°C, 78°C, and 80°C; the reaction time is 1.5-2h, for example, it can be any one value or a range of any two values ​​among 1.5h, 1.6h, 1.8h, and 2h.

[0045] In some specific embodiments of the present invention, the reaction temperature of the third reaction is 81-85°C, for example, it can be any one value or a range of any two values ​​among 81°C, 82°C, 83°C, 84°C, and 85°C; the reaction time is 1.5-2h, for example, it can be any one value or a range of any two values ​​among 1.5h, 1.6h, 1.8h, and 2h.

[0046] In some specific embodiments of the present invention, in step S4, the capping rate of the first capping agent is 75%-85%, for example, it can be any one value or a range of any two values ​​among 75%, 78%, 80%, 82%, and 85%.

[0047] A third aspect of the present invention provides an anti-corrosion coating comprising the silane-modified polyurethane acrylate resin described in any of the foregoing embodiments.

[0048] In some specific embodiments of the present invention, the anti-corrosion coating comprises the following components by weight:

[0049] 15-20 parts of silane-modified polyurethane acrylate resin, 10-15 parts of silane-modified polyether resin, 40-45 parts of modified nano-calcium carbonate, 5-6 parts of fumed silica, 20-23 parts of secondary plasticizer, 4-6 parts of dehydrating agent, 5-8 parts of silane coupling agent, and 0.5-1 parts of coating catalyst.

[0050] Silane-modified polyurethane acrylate resin can achieve both photocuring, rapidly forming a rigid molecular network that imparts high hardness and strength to the material, and rapid moisture curing, forming a dense Si-O-Si network with high crosslinking density, high cohesive strength, and enhanced weather resistance. When combined with silane-modified polyether resin, it helps improve the coating's flexibility. Modified nano-calcium carbonate and fumed silica respectively provide elastic buffering and rigidity enhancement. These, along with the rigid and flexible segments in the silane-modified polyurethane acrylate resin molecule, create a synergistic effect, giving the anti-corrosion material excellent comprehensive performance, meeting the requirements of marine engineering anti-corrosion treatment, and effectively resisting seawater impact, thus extending its service life.

[0051] In some embodiments, typically but not limitingly, for example, the mass fraction of silane-modified polyurethane acrylate resin can be any one value or a range of any two values ​​selected from 15 parts, 16 parts, 18 parts, and 20 parts; the mass fraction of silane-modified polyether resin can be any one value or a range of any two values ​​selected from 10 parts, 12 parts, 14 parts, and 15 parts; the mass fraction of modified nano-calcium carbonate can be any one value or a range of any two values ​​selected from 40 parts, 42 parts, 44 parts, and 45 parts; and the mass fraction of fumed silica can be 5 parts, 5.2 parts, 5.5 parts, and 5.8 parts. The mass fraction of the second plasticizer can be any one value or a range of any two values ​​from 6 parts; the mass fraction of the second plasticizer can be any one value or a range of any two values ​​from 20 parts, 21 parts, 22 parts, and 23 parts; the mass fraction of the dehydrating agent can be any one value or a range of any two values ​​from 4 parts, 4.5 parts, 5 parts, 5.5 parts, and 6 parts; the mass fraction of the silane coupling agent can be any one value or a range of any two values ​​from 5 parts, 6 parts, 7 parts, and 8 parts; the mass fraction of the coating catalyst can be any one value or a range of any two values ​​from 0.5 parts, 0.6 parts, 0.8 parts, and 1 part.

[0052] In some specific embodiments of the present invention, the preparation method of modified nano-calcium carbonate includes the following steps:

[0053] (1) KH570 and KH792 are mixed to obtain the first mixture;

[0054] (2) The first mixture is mixed with an aqueous ethanol solution to obtain a second mixture;

[0055] (3) Place the nano-calcium carbonate in a closed reactor, spray the second mixture into the nano-calcium carbonate under stirring, and stir the reaction under vacuum at 70-80℃ for 2-3 hours to obtain modified nano-calcium carbonate.

[0056] The KH570 on the surface of the modified nano-calcium carbonate participates in free radical polymerization during UV curing, forming covalent bonds with the acrylate network. The diamino catalyst of KH792 catalyzes the hydrolysis-condensation reaction of the silane network, promoting the bonding of the modified powder and resin to form a dense network, effectively resisting seawater penetration into the coating and providing better anti-corrosion performance.

[0057] In some specific embodiments of the present invention, in step (1), the molar ratio of KH570 and KH792 is 1:2-3. For example, it can be any one value or a range of any two values ​​among 1:2, 1:2.2, 1:2.5, 1:2.8, and 1:3.

[0058] In some specific embodiments of the present invention, in step (2), the volume of the ethanol aqueous solution used is 1.5-2.5 times that of the first mixture. For example, it can be any one of the values ​​of 1.5 times, 1.8 times, 2 times, 2.3 times, 2.5 times, or a range of any two values; wherein the ethanol aqueous solution refers to a mixture of ethanol and deionized water.

[0059] In some specific embodiments of the present invention, the mass percentage of ethanol in the ethanol aqueous solution is 97%-98%, for example, it can be any one value or a range of any two values ​​from 97%, 97.2%, 97.5%, 97.8%, 98%.

[0060] In some specific embodiments of the present invention, the spraying amount of the second mixture is 7%-9% of the mass of nano-calcium carbonate, for example, it can be any one value or a range of any two values ​​among 7%, 7.5%, 8%, 8.5%, and 9%.

[0061] In some specific embodiments of the present invention, the oil absorption value of nano-calcium carbonate is 20-30 g / 100 g, and the specific surface area is 20-25 m². 2 / g.

[0062] In some specific embodiments of the present invention, nano-calcium carbonate includes at least one of LP-200, LP-300, and SP200.

[0063] In some specific embodiments of the present invention, the silane-modified polyether resin includes at least one of KERILON 3368T, KERILON 3188T, and KERILON 3900 produced by Jiangsu Ruiyang Antai New Material Technology Co., Ltd.

[0064] In some specific embodiments of the present invention, the fumed silica is hydrophobic silica, which avoids premature curing and failure of the anti-corrosion coating due to water absorption.

[0065] In some specific embodiments of the present invention, fumed silica includes at least one of HB-630, HB-139, and HB-701 from Hubei Huifu Nanomaterials Co., Ltd.

[0066] In some specific embodiments of the present invention, the first plasticizer includes environmentally friendly plasticizer T60 and / or bio-based environmentally friendly plasticizer SK50 produced by Jiangsu Shengkai Plasticizer Technology Co., Ltd.

[0067] In some specific embodiments of the present invention, the dehydrating agent includes vinyltrimethoxysilane and / or vinyltriethoxysilane.

[0068] In some specific embodiments of the present invention, the silane coupling agent includes at least one of KH792, KH-550, and KH540.

[0069] In some specific embodiments of the present invention, the coating catalyst includes at least one of dibutyltin dilaurate, stannous octoate, and HTMS2406 (Nantong Haotai Chemical Products Co., Ltd.).

[0070] In some specific embodiments of the present invention, the method for preparing the anti-corrosion coating includes: mixing each raw material component in proportion and uniformly under vacuum.

[0071] In some preferred embodiments of the present invention, the method for preparing the anti-corrosion coating specifically includes the following steps:

[0072] A portion of the second plasticizer and all of the modified nano-calcium carbonate and fumed silica are added to a stirred tank. Under vacuum, the mixture is stirred until fine and uniform. The remaining second plasticizer, silane-modified polyurethane acrylate resin, and silane-modified polyether resin are added. Under vacuum, the mixture is stirred until uniform. A dehydrating agent, silane coupling agent, and coating catalyst are added. Under vacuum, the mixture is stirred until uniform to obtain an anti-corrosion coating.

[0073] In some embodiments of the present invention, the vacuum state during the reaction or mixing process refers to a vacuum degree of -0.095 MPa to -0.1 MPa inside the container.

[0074] The following detailed description of some embodiments of the present invention is provided in conjunction with specific application examples. Unless otherwise specified, all raw materials used in the embodiments can be obtained commercially available.

[0075] Example 1

[0076] Preparation of silane-modified polyurethane acrylate resin:

[0077] S1. Add 40 parts of ED-28 and 20 parts of T60 to the reactor, control the temperature at 110℃, the vacuum degree below -0.095MPa, and dehydrate for 3 hours;

[0078] S2. Lower the temperature to 75℃, add 4.67 parts of IPDI, control the vacuum degree to below -0.095MPa, and react at 76℃ for 2.5h to obtain NCO-terminated polyurethane prepolymer;

[0079] S3. Add 0.002 parts of TEMPO, stir for 5 min, then add 6.86 parts of pentaerythritol triacrylate, and react at 76℃ for 2 h under nitrogen protection to completely cap the NCO groups.

[0080] S4. Add 6.74 parts of trimethoxysilane and 0.002 parts of KP23, and react at 81°C for 2 hours under nitrogen protection to partially end-cap the first end-capping agent, with an end-capping rate of 80%.

[0081] S5. Add 0.5 parts of initiator TPO, control the vacuum degree below -0.095MPa, stir at 85℃ for 10min to obtain silane modified polyurethane acrylate resin 1.

[0082] Preparation of modified nano-calcium carbonate:

[0083] (1) KH570 and KH792 were mixed evenly at a molar ratio of 1:2 to obtain the first mixture;

[0084] (2) Add 2 times the volume of an aqueous ethanol solution (97% by mass) to the first mixture, mix well, and obtain the second mixture;

[0085] (3) Place nano-calcium carbonate LP-300 in a sealed kettle, turn on high-speed dispersion, add the second mixture by spraying, the weight of which is 7% of the weight of nano-calcium carbonate LP-300, continue high-speed dispersion, turn on high temperature 75℃, control the vacuum degree below -0.095MPa and stir for 3h to obtain modified nano-calcium carbonate 1.

[0086] Preparation of anti-corrosion coatings:

[0087] By weight, 15 parts of T60, 45 parts of modified nano-calcium carbonate, and 5 parts of HB-630 were added to a mixing tank. The vacuum degree was controlled below -0.095 MPa, and high-speed stirring was started to mix until fine and uniform. The remaining 5 parts of T60, 16 parts of silane-modified polyurethane acrylate resin, and 13 parts of KERILON 3368T were added. The vacuum degree was controlled below -0.095 MPa, and high-speed stirring was started to mix uniformly. 5 parts of vinyltrimethoxysilane, 5 parts of KH792, and 0.6 parts of HTMS2406 were added. The vacuum degree was controlled below -0.095 MPa, and high-speed stirring was started to mix uniformly to obtain the anti-corrosion coating.

[0088] Example 2

[0089] Preparation of silane-modified polyurethane acrylate resin:

[0090] S1. Add 30 parts of LHE-3000D and 20 parts of SK50 to the reactor, control the temperature at 110℃ and the vacuum degree below -0.095MPa, and dehydrate for 3 hours;

[0091] S2. Lower the temperature to 75℃, add 3.7 parts of HDI, control the vacuum degree to below -0.095MPa, and react at 76℃ for 2.5h to obtain NCO-terminated polyurethane prepolymer;

[0092] S3. Add 0.002 parts of TEMPO, stir for 5 min, then add 7.15 parts of pentaerythritol triacrylate, and react at 76°C for 2 h under nitrogen protection to completely cap the NCO groups.

[0093] S4. Add 8.84 parts of triethoxysilane and 0.002 parts of caster platinum catalyst, and react at 81°C for 2 hours under nitrogen protection to partially end the first end-capping agent, with an end-capping rate of 78%.

[0094] S5. Add 0.8 parts of photoinitiator 1173, control the vacuum degree below -0.095MPa, stir at 85℃ for 10min to obtain silane-modified polyurethane acrylate resin 2.

[0095] Preparation of modified nano-calcium carbonate:

[0096] (1) KH570 and KH792 were mixed evenly at a molar ratio of 1:2.5 to obtain the first mixture;

[0097] (2) Add 2 times the volume of an aqueous ethanol solution (98% by mass) to the first mixture, mix well, and obtain the second mixture;

[0098] (3) Place nano-calcium carbonate LP-200 in a sealed kettle, turn on high-speed dispersion, add the second mixture by spraying, the weight of which is 7% of the weight of nano-calcium carbonate, continue high-speed dispersion, turn on high temperature 76℃, control the vacuum degree below -0.095MPa and stir for 3h to obtain modified nano-calcium carbonate 2.

[0099] Preparation of anti-corrosion coatings:

[0100] By weight, 15 parts SK50, 43 parts modified nano-calcium carbonate, and 6 parts HB-139 were added to a mixing tank. The vacuum degree was controlled below -0.095 MPa, and high-speed stirring was started to mix until fine and uniform. The remaining 6 parts SK50, 20 parts silane-modified polyurethane acrylate resin, and 13 parts KERILON 3188T were added. The vacuum degree was controlled below -0.095 MPa, and high-speed stirring was started to mix evenly. 5 parts vinyltrimethoxysilane, 6 parts KH540, and 0.6 parts dibutyltin dilaurate were added. The vacuum degree was controlled below -0.095 MPa, and high-speed stirring was started to mix evenly to obtain the anti-corrosion coating.

[0101] Example 3

[0102] Preparation of silane-modified polyurethane acrylate resin:

[0103] S1. Add 40 parts of LHE-4000D and 15 parts of SK50 to the reactor, control the temperature at 120℃, the vacuum degree below -0.095MPa, and dehydrate for 2.5h;

[0104] S2. Lower the temperature to 80℃, add 5.77 parts of HMDI, control the vacuum degree to below -0.095MPa, and react at 75℃ for 3 hours to obtain NCO-terminated polyurethane prepolymer;

[0105] S3. Add 0.005 parts of TEMPO, stir for 10 min, then add 7.46 parts of pentaerythritol triacrylate, and react at 75°C for 2 h under nitrogen protection to completely cap the NCO groups.

[0106] S4. Add 7.51 parts of trimethoxysilane and 0.003 parts of PT-5000, and react at 82°C for 2 hours under nitrogen protection to partially end-cap the first end-capping agent, with an end-capping rate of 82%.

[0107] S5. Add 1 part of photoinitiator TPO, control the vacuum degree below -0.095MPa, stir at 83℃ for 5 min to obtain silane-modified polyurethane acrylate resin 3.

[0108] Preparation of modified nano-calcium carbonate:

[0109] (1) KH570 and KH792 were mixed evenly at a molar ratio of 1:3 to obtain the first mixture;

[0110] (2) Add 2 times the volume of an aqueous ethanol solution (97% by mass) to the first mixture, mix well, and obtain the second mixture;

[0111] (3) Place the nano-calcium carbonate SP200 in a sealed kettle, turn on high-speed dispersion, add the second mixture by spraying, the weight of which is 8% of the weight of the nano-calcium carbonate, continue high-speed dispersion, turn on high temperature 76℃, control the vacuum degree below -0.095MPa and stir for 3h to obtain modified nano-calcium carbonate 3.

[0112] Preparation of anti-corrosion coatings:

[0113] By weight, 15 parts of T60, 45 parts of modified nano-calcium carbonate, and 6 parts of HB-701 were added to a mixing tank. The vacuum degree was controlled below -0.095 MPa, and high-speed stirring was started to mix until fine and uniform. The remaining 7 parts of T60, 19 parts of silane-modified polyurethane acrylate resin, and 15 parts of KERILON 3900 were added. The vacuum degree was controlled below -0.095 MPa, and high-speed stirring was started to mix uniformly. 6 parts of vinyltriethoxysilane, 8 parts of KH-550, and 1 part of stannous octoate were added. The vacuum degree was controlled below -0.095 MPa, and high-speed stirring was started to mix uniformly to obtain the anti-corrosion coating.

[0114] Example 4

[0115] Preparation of silane-modified polyurethane acrylate resin:

[0116] S1. Add 40 parts of ED-28 and 19 parts of SK50 to the reactor, control the temperature at 120℃, the vacuum degree below -0.095MPa, and dehydrate for 2.5h;

[0117] S2. Lower the temperature to 80℃, add 4.67 parts of IPDI, control the vacuum degree to below -0.095MPa, and react at 75℃ for 3 hours to obtain NCO-terminated polyurethane prepolymer;

[0118] S3. After adding 0.005 parts of TEMPO and stirring for 10 min, add 12.06 parts of polydipentaerythritol pentaacrylate and react at 75°C for 2 h under nitrogen protection to completely end the NCO groups.

[0119] S4. Add 15.11 parts of triethoxysilane and 0.004 parts of PT-5000, and react at 82°C for 2 hours under nitrogen protection to partially end-cap the first end-capping agent, with an end-capping rate of 80%.

[0120] S5. Add 1 part of photoinitiator TPO, control the vacuum degree below -0.095MPa, stir at 83℃ for 5 min to obtain silane-modified polyurethane acrylate resin 4.

[0121] The modified nano-calcium carbonate used was the modified nano-calcium carbonate 3 prepared in Example 3.

[0122] Preparation of anti-corrosion coatings:

[0123] By weight, 15 parts SK50, 42 parts modified nano-calcium carbonate, and 6 parts HB-630 were added to a mixing tank. The vacuum degree was controlled below -0.095 MPa, and high-speed stirring was started to mix until fine and uniform. The remaining 6 parts SK50, 18 parts silane-modified polyurethane acrylate resin, and 15 parts KERILON 3368T were added. The vacuum degree was controlled below -0.095 MPa, and high-speed stirring was started to mix uniformly. 6 parts vinyltrimethoxysilane, 8 parts KH792, and 0.8 parts HTMS2406 were added. The vacuum degree was controlled below -0.095 MPa, and high-speed stirring was started to mix uniformly to obtain the anti-corrosion coating.

[0124] Comparative Example 1

[0125] Comparative Example 1 is similar to Example 1, except that: the first capping agent was changed from 6.86 parts pentaerythritol triacrylate to 33 parts hydroxyl-terminated polybutadiene Polybd R-15M, and all NCO groups were capped using hydroxyl-terminated polybutadiene Polybd R-15M; the amount of the second capping agent trimethoxysilane was adjusted to 1.08 parts (keeping the capping rate of the first capping agent the same as in Example 1); all other conditions were the same as in Example 1.

[0126] Comparative Example 2

[0127] Comparative Example 2 is similar to Example 1, except that the second capping agent was replaced with 5.86 parts of methyldimethoxysilane instead of 6.74 parts of trimethoxysilane (keeping the capping rate of the first capping agent the same as in Example 1); all other conditions were the same as in Example 1.

[0128] Comparative Example 3

[0129] Comparative Example 3 is similar to Example 2, except that KH792 was replaced with an equal amount of KH570 when preparing modified nano-calcium carbonate; all other conditions were the same as in Example 2.

[0130] Comparative Example 4

[0131] Comparative Example 4 is similar to Example 2, except that KH570 was replaced with an equal amount of KH792 when preparing modified nano-calcium carbonate; all other conditions are the same as in Example 2.

[0132] Comparative Example 5

[0133] Comparative Example 5 is similar to Example 2, except that the nano-calcium carbonate was not modified; all other conditions are the same as in Example 2.

[0134] Comparative Example 6

[0135] Comparative Example 6 is similar to Example 3, except that the amount of the second capping agent, trimethoxysilane, was adjusted from 7.51 parts to 9.17 parts to completely cap the first capping agent; all other conditions are the same as in Example 3.

[0136] Comparative Example 7

[0137] Comparative Example 7 is similar to Example 3, except that the amount of the second capping agent, trimethoxysilane, was adjusted from 7.51 parts to 5.5 parts, and the capping rate of the first capping agent was 60%; all other conditions were the same as in Example 3.

[0138] Comparative Example 8

[0139] Comparative Example 8 is similar to Example 4, except that the amount of the second capping agent, triethoxysilane, was adjusted from 15.11 parts to 17.94 parts, and the first capping agent was capped by 95%; all other conditions were the same as in Example 4.

[0140] Comparative Example 9

[0141] Comparative Example 9 is similar to Example 4, except that the amount of the second capping agent, triethoxysilane, was adjusted from 15.11 parts to 13.22 parts, and the first capping agent was capped by 70%; all other conditions were the same as in Example 4.

[0142] Comparative Example 10

[0143] Comparative Example 10 is similar to Example 1, except that: when preparing the anti-corrosion coating, 16 parts of silane-modified polyurethane acrylate resin 1 were replaced with 15.5g of KERILON 3368T and 0.5g of pentaerythritol triacrylate; all other conditions were the same as in Example 1.

[0144] Test case

[0145] The anti-corrosion coatings in each embodiment and comparative example were tested separately. The product performance testing methods are as follows:

[0146] Tensile strength and elongation at break: The film was prepared according to Chapter 4 of GB / T 16777-2008, with a film thickness of (1.5±0.2) mm. It was irradiated with a 365nm-405nm UV-LED light source for 5 seconds and then cured under standard conditions for 7 days. After curing, the test was carried out according to Chapter 9 of GB / T 16777-2008, with a test speed of (500±50) mm / min.

[0147] Bond strength: Using cold-rolled steel sheet as the substrate as specified in GB / T9271-2008, a uniform coating of (1.5±0.2) mm was applied. The coating was then irradiated with a 365nm-405nm UV-LED light source for 5 seconds and cured under standard conditions for 7 days. After curing, the test was conducted according to GB / T5210-2006 using a test column with a diameter of 20 mm.

[0148] Tear strength: The film was prepared according to Chapter 4 of GB / T 16777-2008, with a film thickness of (1.5±0.2) mm. It was irradiated with a 365nm-405nm UV-LED light source for 5 seconds and then cured under standard conditions for 7 days. After curing, the right-angled specimens were tested according to GB / T 529-2008 without cutting, and the tensile speed was (500±50) mm / min.

[0149] Salt spray aging: Cold-rolled steel sheet as specified in GB / T9271-2008 was used as the substrate, and a coating of (1.5±0.2) mm was applied. The coating was then irradiated with a 365nm-405nm UV-LED light source for 5 seconds, followed by curing under standard conditions for 7 days. After curing, the test was conducted in accordance with GB / T1771-2007, with a test cycle of 30 days.

[0150] Artificial climate aging: The membrane was prepared according to Chapter 4 of GB / T 16777-2008, with a thickness of (1.5±0.2) mm. It was irradiated with a 365nm-405nm UV-LED light source for 5 seconds, followed by curing under standard conditions for 7 days. The cured membrane was then placed in seawater in an artificial climate aging test chamber and tested according to GB / T 16422.2-2004, with a cumulative irradiance reaching 5040 kJ / (m²). 2 The membrane (·nm) was removed from the seawater and placed in an artificial climate aging test chamber. Testing was conducted according to GB / T 16422.2-2004, and the cumulative irradiance again reached 5040 kJ / (m²). 2 After being taken out for testing (·nm), the coating was simulated to demonstrate the impact of climate on anti-corrosion coatings under ocean tidal changes.

[0151] Under standard conditions, a coating film of (1.5±0.2) mm is made using a mold. The film is irradiated with a 365nm-405nm UV-LED light source for 5 seconds, and the timing is started. The time when the coating film is picked up with a glass rod and becomes obviously stringy is the initial curing time. The time when the coating film is cut with a knife and no wet coating sticks to the knife, and the coating film is elastic and intact when pulled by hand, is the complete drying time.

[0152] The test results are shown in Tables 1, 2 and 3.

[0153] Table 1

[0154]

[0155] As shown in Table 1, the anti-corrosion coating prepared by this invention possesses high tensile strength, tear strength, and bond strength, with an elongation at break exceeding 200%, indicating excellent flexibility and resistance to long-term wave impact. After artificial climate aging under simulated seawater tidal conditions, the tensile strength retention rate is above 95%, demonstrating good weather resistance. After rigorous salt spray aging, the bonding effect is good, and no rust appears on the substrate at the bottom of the coating. Under ultraviolet light irradiation, it completes photocuring in about 2 minutes, forming a preliminary rigid molecular network that effectively resists the initial impact of seawater erosion. The siloxane groups have high activity, allowing for rapid moisture curing, and the product dries quickly, meeting the needs of rapid construction.

[0156] Table 2

[0157]

[0158] As shown in Table 2, changing the first end-capping agent from pentaerythritol triacrylate to hydroxyl-terminated polybutadiene Polybd R-15M weakens the branching degree of the siloxane groups in the silane-modified polyurethane acrylate resin, resulting in lower activity and a slower curing speed. This prevents the formation of a suitable network structure where flexible segments intersect between rigid segments, leading to poorer salt spray resistance and weather resistance. Furthermore, the product cannot achieve photocuring and its strength decreases. Replacing the second end-capping agent, trimethoxysilane, with methyldimethoxysilane reduces mechanical properties, weather resistance, and curing speed. Rusting occurs after salt spray aging, resulting in poorer corrosion protection. When nano-calcium carbonate is not modified according to the present invention, its tear strength decreases, its flexibility deteriorates, and its corrosion resistance worsens.

[0159] Table 3

[0160]

[0161] The data in Table 3 show that when preparing silane-modified polyurethane acrylate resin, complete or excessively high end-capping of the first end-capping agent can lead to inability to achieve photocuring or excessively long initial curing time, which is detrimental to resistance to initial seawater erosion, resulting in decreased mechanical properties, reduced flexibility, corrosion after salt spray aging, and poor corrosion protection. Conversely, excessively low end-capping of the first end-capping agent increases tensile strength, decreases tear strength, reduces elongation at break, reduces flexibility, decreases the retention rate of tensile strength under artificial climate aging, worsens weather resistance, and leads to corrosion after salt spray aging, resulting in poor corrosion protection. This indicates that the degree of end-capping of the first end-capping agent affects the ratio of photocuring to moisture curing, thereby affecting product performance. Adding pentaerythritol triacrylate monomer alone to the system results in a significant performance degradation and fails to achieve the desired effect of introducing it into the silane-modified polyurethane acrylate resin molecule.

[0162] Although the present invention has been illustrated and described with specific embodiments, it should be understood that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; those skilled in the art should understand that modifications can 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 therein, without departing from the spirit and scope of the present invention; 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; therefore, this means that all such substitutions and modifications that fall within the scope of the present invention are included in the appended claims.

Claims

1. A silane-modified polyurethane acrylate resin, characterized in that, By mass, the raw materials comprise the following components: 25-45 parts of polyether polyol, 10-20 parts of first plasticizer, 3-6 parts of isocyanate, 0.002-0.005 parts of inhibitor, 5-15 parts of first end-capping agent, 6-18 parts of second end-capping agent, 0.002-0.005 parts of resin catalyst, and 0.5-2 parts of photoinitiator; Wherein, the first end-capping agent includes pentaerythritol triacrylate and / or polydipentaerythritol pentaacrylate; the second end-capping agent includes trimethoxysilane and / or triethoxysilane; The preparation method of the silane-modified polyurethane acrylate resin includes the following steps: S1. The polyether polyol and the first plasticizer are mixed and then subjected to vacuum dehydration; S2. Add the isocyanate and carry out the first reaction under vacuum or inert gas protection to obtain NCO-terminated polyurethane prepolymer; S3. After adding the inhibitor and mixing, add the first capping agent and carry out the second reaction under vacuum or inert gas protection to cap all NCO groups; S4. Add the second capping agent and the resin catalyst, and carry out the third reaction under vacuum or inert gas protection to partially cap the first capping agent, with a capping rate of 75%-85%; S5. Add a photoinitiator and mix under vacuum to obtain the silane-modified polyurethane acrylate resin.

2. The silane-modified polyurethane acrylate resin according to claim 1, characterized in that, The second capping agent is trimethoxysilane, in parts by mass of 6-14; or, the second capping agent is triethoxysilane, in parts by mass of 8-18.

3. The silane-modified polyurethane acrylate resin according to claim 1 or 2, characterized in that, It meets at least one of the following characteristics: (1) The number average molecular weight of the polyether polyol is 2800-4200 g / mol and the functionality is 2; (2) The polyether polyol includes at least one of ED-28, LHE-3000D, and LHE-4000D; (3) The isocyanate includes at least one of IPDI, HDI, and HMDI; (4) The first plasticizer includes T60 and / or SK50; (5) The inhibitors include TEMPO and / or BHT; (6) The resin catalyst includes a Castells platinum catalyst; (7) The photoinitiator includes (2,4,6-trimethylbenzoyl)diphenylphosphine oxide and / or 2-hydroxy-2-methyl-1-phenyl-1-propanone.

4. The silane-modified polyurethane acrylate resin according to claim 3, characterized in that, The Castel platinum catalyst includes KP23 and / or PT-5000 platinum catalyst.

5. The method for preparing the silane-modified polyurethane acrylate resin according to any one of claims 1-4, characterized in that, Includes the following steps: S1. Mix the polyether polyol and the first plasticizer and then dehydrate them under vacuum; S2. Add isocyanate and carry out the first reaction under vacuum or inert gas protection to obtain NCO-terminated polyurethane prepolymer; S3. After adding the inhibitor and mixing, add the first capping agent and carry out the second reaction under vacuum or inert gas protection to cap all NCO groups; S4. Add the second capping agent and resin catalyst, and carry out the third reaction under vacuum or inert gas protection to partially cap the first capping agent; S5. Add a photoinitiator and mix under vacuum to obtain the silane-modified polyurethane acrylate resin.

6. The method for preparing silane-modified polyurethane acrylate resin according to claim 5, characterized in that, It meets at least one of the following characteristics: (1) The reaction temperature of the first reaction is 75-80℃ and the reaction time is 2.5-3h; (2) The reaction temperature of the second reaction is 75-80℃, and the reaction time is 1.5-2h; (3) The reaction temperature of the third reaction is 81-85℃, and the reaction time is 1.5-2h; (4) In step S4, the capping rate of the first capping agent is 75%-85%.

7. A coating, characterized in that, The coating comprises the following components by weight: The composition comprises 15-20 parts of silane-modified polyurethane acrylate resin, 10-15 parts of silane-modified polyether resin, 40-45 parts of modified nano-calcium carbonate, 5-6 parts of fumed silica, 20-23 parts of a second plasticizer, 4-6 parts of a dehydrating agent, 5-8 parts of a silane coupling agent, and 0.5-1 parts of a coating catalyst; wherein the silane-modified polyurethane acrylate resin is the silane-modified polyurethane acrylate resin according to any one of claims 1-4. The preparation method of the modified nano-calcium carbonate includes the following steps: (1) KH570 and KH792 are mixed to obtain the first mixture; (2) The first mixture is mixed with an aqueous ethanol solution to obtain a second mixture; (3) Place the nano-calcium carbonate in a closed reactor, spray the second mixture into the nano-calcium carbonate under stirring, and stir the reaction under vacuum at 70-80°C for 2-3 hours to obtain the modified nano-calcium carbonate.

8. The coating according to claim 7, characterized in that, It meets at least one of the following characteristics: (1) The molar ratio of KH570 and KH792 is 1:2-3; (2) The volume of the ethanol-water solution is 1.5-2.5 times that of the first mixture; (3) In the ethanol-water solution, the mass percentage of ethanol is 97%-98%; (4) The amount of the second mixture sprayed is 7%-9% of the mass of the nano-calcium carbonate; (5) The oil absorption value of the nano-calcium carbonate is 20-30 g / 100 g, and the specific surface area is 20-25 m². 2 / g; (6) The nano calcium carbonate includes at least one of LP-200, LP-300 and SP200.

9. The coating according to claim 7 or 8, characterized in that, It meets at least one of the following characteristics: (1) The silane-modified polyether resin includes at least one of KERILON 3368T, KERILON 3188T, and KERILON 3900; (2) The fumed silica is hydrophobic silica; (3) The fumed silica includes at least one of HB-630, HB-139, and HB-701; (4) The second plasticizer includes T60 and / or SK50; (5) The dehydrating agent includes vinyltrimethoxysilane and / or vinyltriethoxysilane; (6) The silane coupling agent includes at least one of KH792, KH-550, and KH540; (7) The coating catalyst includes at least one of dibutyltin dilaurate, stannous octoate, and HTMS2406.

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