A high-wear-resistance antifouling normal-temperature curing polysilazane coating, a preparation method and application thereof

Abstract

The present application belongs to the technical field of coating preparation, and provides a high-wear-resistance and anti-fouling normal-temperature curing polysilazane coating, a preparation method and application thereof.The present application takes epoxy side group polysilazane resin as a film-forming main body, and the resin is obtained by reacting perhydropolysilazane with allyl glycidyl ether under the action of Karstedt catalyst;an amphoteric ion amphiphilic functional copolymer containing silicon anchoring is matched to form an anti-fouling interface on the surface of the coating film;latent amine curing agent is introduced, the latent amine curing agent is obtained by grafting branched polyethyleneimine with ketone imine closure and / or epoxy functional silane, so that the system can give consideration to construction pot life and normal-temperature crosslinking and curing;and a hybrid interpenetrating structure of organic crosslinking network and siloxane network is constructed in cooperation with a siloxane condensation crosslinking agent, the coating takes di-n-butyl ether as a solvent, adopts a quaternary ammonium salt catalytic system and can be separately packaged with a strong alkali to promote the reaction components, and the obtained coating is suitable for wear-resistance and anti-fouling protection of metals, ceramics and composite materials.

Description

Technical Field

[0001] This invention belongs to the field of coating preparation technology, and relates to a high wear-resistant and stain-resistant room-temperature curing polysilazane coating, its preparation method and application. Background Technology

[0002] Polysilazane materials have attracted attention in the field of protective coatings due to their ability to transform into a silicon-oxygen network structure after film formation, good heat and weather resistance, and strong adhesion potential to various substrates. However, when facing applications that require both high wear resistance and anti-fouling properties, existing room-temperature curing polysilazane coating systems still have several shortcomings, making it difficult to simultaneously achieve workability, film density, and long-term surface anti-fouling stability.

[0003] On the one hand, to achieve high crosslinking density, polysilazane systems often incorporate reactive groups such as epoxy and silane groups, along with amine curing agents, to achieve room-temperature curing. However, amine curing agents are typically highly reactive, easily causing rapid thickening, shortening the pot life, or even gelling risks during paint formulation or application, thus limiting the storage or long-term workability of single-component systems. Especially in solvent-based systems, the combined effects of solvent evaporation, air humidity fluctuations, and the presence of catalysts further exacerbate the uncertainty of the curing rate, making it difficult to stably control the application window. On the other hand, the abrasion resistance of polysilazane coatings relies more on the formation of the inorganic network and the densification of the coating film. However, the coupling process of network transformation and organic crosslinking under room-temperature conditions is complex. If the organic crosslinking and siloxane condensation processes are mismatched, it can easily lead to local phase separation, micro-defects, or uneven surface energy, thereby affecting the synergistic performance of abrasion resistance and stain resistance.

[0004] Furthermore, antifouling performance often depends on the regulation of coating surface energy and the construction of the interfacial hydration layer. Existing solutions often achieve hydrophobic antifouling by adding fluorinated additives, silicone oil, or inorganic fillers, or by introducing hydrophilic modified components to improve antifouling ability. However, these solutions are prone to problems such as uncontrolled additive migration, insufficient durability, poor compatibility with the substrate, and attenuation of surface effects. For polysilazane systems, if the antifouling component exists only in a physical blending manner, it may agglomerate or be embedded inside the coating during film formation, making it difficult to form a stable and effective functional layer on the surface, resulting in inconsistencies between initial performance and long-term performance. At the same time, the practice of using high fillers or high-hardness inorganic components to improve wear resistance may bring new problems such as increased system viscosity, poor workability, coating embrittlement, and decreased adhesion, which is not conducive to widespread application on complex substrates and under field conditions. Summary of the Invention

[0005] To address the shortcomings of existing technologies, the present invention aims to provide a high-wear-resistant and anti-fouling room-temperature curing polysilazane coating, its preparation method, and its application. The coating uses epoxy-side-group polysilazane resin as the film-forming matrix, combined with a silicon-anchored zwitterionic amphiphilic functional copolymer to construct a surface anti-fouling interface. A latent amine curing agent obtained by branched polyethyleneimine blocked with ketimine and / or grafted with epoxy silane is introduced, working synergistically with a siloxane condensation crosslinking agent and a catalytic system to achieve room-temperature curing, resulting in a coating that combines wear resistance and anti-fouling properties, thus meeting the needs of practical production.

[0006] To achieve this objective, the present invention adopts the following technical solution:

[0007] In a first aspect, the present invention provides a high wear-resistant and stain-resistant room-temperature curing polysilazane coating, comprising, by weight: 100 parts of epoxy-side-chain polysilazane resin, 1-6 parts of silane-anchored zwitterionic amphiphilic functional copolymer, 5-30 parts of latent amine curing agent, 0.5-20 parts of siloxane condensation crosslinking agent, 0.05-1.50 parts of catalyst, and 50-300 parts of di-n-butyl ether; wherein the catalyst comprises at least tetrabutylammonium chloride.

[0008] Preferably, the epoxy-side-chain polysilazane resin is obtained by reacting the following raw materials, which, by mass, include: 100 parts of perhydropolysilazane di-n-butyl ether solution, 1-8 parts of allyl glycidyl ether, and 0.005-0.050 parts of caster catalyst; wherein the perhydropolysilazane di-n-butyl ether solution has a solid content of 20 wt.% and the solvent is di-n-butyl ether.

[0009] Preferably, the silane-anchored zwitterionic amphiphilic functional copolymer is a copolymer obtained by free radical copolymerization, and its repeating units include: lauryl methacrylate, 2-(dimethylamino)ethyl methacrylate and 3-(trimethoxysilyl)propyl methacrylate.

[0010] Preferably, the silane-anchored zwitterionic amphiphilic functional copolymer comprises a sulfobetaine structure introduced by 1,3-propanesulfonyl lactone.

[0011] Preferably, the latent amine curing agent is any one of ketimide-blocked branched polyethyleneimine, silanized branched polyethyleneimine, or ketimide-blocked and silanized branched polyethyleneimine.

[0012] The ketimine-blocked branched polyethyleneimine is prepared by reacting branched polyethyleneimine with methyl ethyl ketone or methyl isobutyl ketone;

[0013] The silanized branched polyethyleneimine is prepared by a ring-opening addition reaction of branched polyethyleneimine and 3-glycidoxypropyltrimethoxysilane;

[0014] The ketoimine-blocked and silanized branched polyethyleneimine is prepared by reacting branched polyethyleneimine, methyl ethyl ketone or methyl isobutyl ketone with 3-glycidoxypropyltrimethoxysilane.

[0015] Preferably, the siloxane condensation crosslinking agent is one or more of tetraethoxysilane, methyltrimethoxysilane, and 3-glycidoxypropyltrimethoxysilane; and the catalyst, in addition to tetrabutylammonium chloride, also includes one or two of 1,8-diazabicyclo[5.4.0]undecyl-7-ene or 1,4-diazabicyclo[2.2.2]octane; wherein the 1,8-diazabicyclo[5.4.0]undecyl-7-ene is packaged separately from the other components and mixed with the other components before use.

[0016] Secondly, the present invention provides a method for producing a highly wear-resistant and stain-resistant room-temperature curing polysilazane coating, comprising the following steps:

[0017] S1) Mix the perhydropolysilazane di-n-butyl ether solution with the caster catalyst, add allyl glycidyl ether at 40-60℃ and react for 2-6 hours, then cool to obtain epoxy side-chain polysilazane resin.

[0018] S2) Lauryl methacrylate, 2-(dimethylamino)ethyl methacrylate, 3-(trimethoxysilyl)propyl methacrylate and 2,2′-azobis(2-methylpropionitrile) were added to N,N-dimethylformamide and polymerized at 65-75℃ for 4-12 h to obtain a copolymer solution; 1,3-propane sulpholactone was added to the copolymer solution and reacted for 4-12 h to obtain a silane-anchored zwitterionic amphiphilic functional copolymer; and solvent substitution was performed to obtain a di-n-butyl ether system silane-anchored zwitterionic amphiphilic functional copolymer;

[0019] S3) Preparation of a latent amine curing agent, wherein the preparation includes any one or more of the following:

[0020] S3-1) Branched polyethyleneimine is mixed with methyl ethyl ketone or methyl isobutyl ketone and reacted at 30-45℃ for 4-8 hours to obtain ketimine-blocked branched polyethyleneimine.

[0021] S3-2) Branched polyethyleneimine is mixed with 3-glycidyloxypropyltrimethoxysilane and reacted at 30-50℃ for 4-8h to obtain silanized branched polyethyleneimine.

[0022] S3-3) The ketimine-blocked branched polyethyleneimine obtained in S3-1 is mixed with 3-glycidyloxypropyltrimethoxysilane and reacted at 30-50℃ for 3-6h to obtain ketimine-blocked and silanized branched polyethyleneimine.

[0023] S4) Epoxy-side-chain polysilazane resin, silane-anchored zwitterionic amphiphilic functional copolymer, latent amine curing agent, siloxane condensation crosslinking agent, tetrabutylammonium chloride and di-n-butyl ether are mixed and degassed; a catalyst component containing 1,8-diazabicyclo[5.4.0]undecyl-7-ene is mixed with the mixture to obtain a high wear-resistant and anti-fouling room-temperature curing polysilazane coating.

[0024] Preferably, in the preparation of the ketimine-blocked branched polyethyleneimine, by mass parts: 100 parts of branched polyethyleneimine and 50-250 parts of methyl ethyl ketone or methyl isobutyl ketone;

[0025] In the preparation of the silanized branched polyethyleneimine, by mass parts: 100 parts of branched polyethyleneimine and 5-80 parts of 3-glycidyloxypropyltrimethoxysilane;

[0026] In the preparation of the ketimine-blocked branched polyethyleneimine, by mass parts: 100 parts of branched polyethyleneimine, 50-250 parts of methyl ethyl ketone or methyl isobutyl ketone, and 5-80 parts of 3-glycidyloxypropyltrimethoxysilane.

[0027] In step S1, the perhydropolysilazane backbone contains silicon-nitrogen bonds and silicon-hydrogen bonds. The Castanet catalyst causes the silicon-hydrogen bonds to add to the carbon-carbon double bonds of allyl glycidyl ether, introducing epoxy-containing organic side groups. The epoxy groups are not used as reaction sites in this step but are retained as reactive groups for subsequent room-temperature crosslinking. The resulting epoxy-side-group polysilazane resin possesses both a moisture-convertible polysilazane backbone and amine-curable epoxy side groups.

[0028] In step S2, lauryl methacrylate, 2-(dimethylamino)ethyl methacrylate, and 3-(trimethoxysilyl)propyl methacrylate undergo free radical copolymerization under the action of an azo initiator to form an amphiphilic copolymer segment. The lauryl side chain provides a source of organic phase compatibility, the tertiary amine side group provides a site for subsequent quaternization, and the trimethoxysilane side group hydrolyzes to silanol under humid conditions and condenses to form a siloxane bond, becoming a chemical anchoring point for embedding the copolymer into the siloxane network. After the addition of 1,3-propanesulfonyl lactone, the tertiary amine undergoes nucleophilic ring-opening quaternization to generate a sulfobetaine inner salt structure. This zwitterionic structure forms a hydration layer with water molecules, affecting the adsorption and spreading of pollutants at the interface.

[0029] In step S3, the latent amine curing agent is obtained through ketimine blocking and / or silanization grafting. Ketones condense with the primary amine of branched polyethyleneimine to form ketimines, converting some of the amines from an immediately reactive form to a hydrolyzable and release form. Under the influence of moisture, the ketimine hydrolyzes to release the primary amine, achieving moisture-triggered amine supply. 3-Glycidyloxypropyltrimethoxysilane undergoes epoxy ring-opening addition with the amine group of polyethyleneimine to form a β-hydroxyamine bond structure, introducing a hydrolyzable alkoxysilane site onto the molecule. This site hydrolyzes to a silanol and condenses into a siloxane bond, enabling the curing agent to simultaneously possess the linking functions of epoxy curing and siloxane network crosslinking. When ketimine blocking and silanization are superimposed, the amine release and silane condensation within the same molecule participate in network construction in parallel during the curing stage.

[0030] In step S4, the components are mixed to form a multi-reaction-site system, the reaction initiation and rate of which are controlled by moisture and catalytic strength. The siloxane condensation crosslinking agent hydrolyzes to generate silanols upon the introduction of moisture, which then condense to form siloxane bonds. The epoxy functional silane simultaneously provides condensable silane sites and amine-opening epoxy sites. Tetrabutylammonium chloride influences epoxy ring-opening and the system's microstructure through ionic environment and nucleophilic interactions. After coating, solvent evaporation and moisture diffusion occur in parallel. Moisture drives the hydrolysis of ketimines to release amines, which then undergo ring-opening addition to the epoxy side groups to form β-hydroxyamine bonds. The branched structure brings multi-point connections and forms an organic crosslinking network. Simultaneously, the silicon-nitrogen bonds in the polysilazane backbone hydrolyze to generate silanols, which further condense to form siloxane bonds. The alkoxysilane sites on the crosslinking agent, functional copolymer, and silanized curing agent simultaneously hydrolyze and condense, co-condensing with the silanols in the system to form covalent bridges, coupling the organic network and the siloxane network at the bonding level. The zwitterionic side groups form a hydrated layer at the air-side interface and are fixed after condensation and curing. The final coating is composed of an epoxy-amine crosslinked network and a silicon-oxygen network, with the zwitterionic hydrated interface on the surface forming a structural association with the bulk hybrid network.

[0031] Thirdly, the high wear-resistant and anti-fouling room-temperature curing polysilazane coating provided by the present invention is applied in the field of wear-resistant and anti-fouling.

[0032] Compared with the prior art, the beneficial effects of the present invention are as follows: The polysilazane coating provided by the present invention uses epoxy-side-group polysilazane resin as the film-forming body. The epoxy side groups provide reaction sites for subsequent room-temperature crosslinking. The polysilazane backbone undergoes hydrolysis and condensation under humid conditions to form a silicon-oxygen network, so that the coating structure simultaneously contains an organic crosslinking network and a silicon-oxygen network and achieves synergistic curing. The introduced zwitterionic amphiphilic functional copolymer has both hydrophobic compatible segments and hydrated internal salt groups, and participates in the condensation reaction through silicon-containing anchoring units, thereby forming a coating on the surface. A stable hydration interface is established and chemically linked with the bulk network, reducing the adsorption and adhesion of surface contaminants. The latent amine curing agent is obtained by blocking branched polyethyleneimine with ketimine and / or grafting with epoxy silane. During the curing process, the amine is released by moisture trigger and participates in the ring-opening crosslinking of epoxy. At the same time, condensable silane sites are introduced to achieve the regulation of the pot life and curing process and strengthen the coupling of organic-inorganic networks. Combined with the siloxane condensation crosslinking agent and catalytic system, a dense and continuous coating can be formed under room temperature conditions, which is suitable for wear-resistant and anti-fouling protection on the surface of various substrates. Attached Figure Description

[0033] Figure 1 The FTIR spectrum of the silane-anchored zwitterionic amphiphilic functional copolymer provided in Example 1 of this invention; Detailed Implementation

[0034] The technical solutions of the present invention will be described in detail below with reference to specific embodiments and accompanying drawings. The embodiments described herein are specific implementations of the present invention, used to illustrate the concept of the present invention; these descriptions are explanatory and exemplary, and should not be construed as limiting the implementation methods or the scope of protection of the present invention. In addition to the embodiments described herein, those skilled in the art can employ other obvious technical solutions based on the content disclosed in the claims and specification of this application. These technical solutions include those that make any obvious substitutions and modifications to the embodiments described herein.

[0035] The chemical reagents used in the embodiments and comparative examples of this invention are all commercially available products and have not undergone any further purification treatment.

[0036] Example 1

[0037] This embodiment provides a high wear-resistant and stain-resistant room-temperature curing polysilazane coating and its preparation method, specifically including:

[0038] The product comprises, by weight, 100 parts of epoxy-side-coated polysilazane resin, 1 part of silane-anchored zwitterionic amphiphilic functional copolymer, 30 parts of latent amine curing agent, 10 parts of siloxane condensation crosslinking agent, 0.05 parts of catalyst, and 200 parts of di-n-butyl ether; wherein the catalyst comprises tetrabutylammonium chloride and 1,8-diazabicyclo[5.4.0]undecyl-7-ene in a mass ratio of 1:1.

[0039] The epoxy-side-chain polysilazane resin is obtained by reacting the following raw materials, which, by mass, include: 100 parts of perhydropolysilazane di-n-butyl ether solution, 8 parts of allyl glycidyl ether, and 0.005 parts of caster catalyst; wherein, the perhydropolysilazane di-n-butyl ether solution has a solid content of 20 wt.% and the solvent is di-n-butyl ether;

[0040] The silane-anchored zwitterionic amphiphilic functional copolymer is a copolymer obtained by free radical copolymerization, and its repeating units include: lauryl methacrylate, 2-(dimethylamino)ethyl methacrylate and 3-(trimethoxysilyl)propyl methacrylate.

[0041] The silane-anchored zwitterionic amphiphilic functional copolymer includes a sulfobetaine structure introduced by 1,3-propanesulfonyl lactone.

[0042] The latent amine curing agent is a branched polyethyleneimine blocked and silanized with ketimine, which is obtained by reacting the following raw materials, comprising, by mass: 100 parts of branched polyethyleneimine, 50 parts of methyl ethyl ketone, and 80 parts of 3-glycidoxypropyltrimethoxysilane.

[0043] The siloxane condensation crosslinking agent is tetraethoxysilane;

[0044] The preparation method includes the following steps:

[0045] S1) A solution of perhydropolysilazane di-n-butyl ether was mixed with a caster catalyst, and allyl glycidyl ether was added at 60°C and reacted for 2 hours. After cooling, epoxy-side-chain polysilazane resin was obtained.

[0046] S2) Lauryl methacrylate, 2-(dimethylamino)ethyl methacrylate, 3-(trimethoxysilyl)propyl methacrylate and 2,2′-azobis(2-methylpropionitrile) were added to N,N-dimethylformamide and polymerized at 65°C for 12 h to obtain a copolymer solution; 1,3-propane sulpholactone was added to the copolymer solution and reacted for 4 h to obtain a silane-anchored zwitterionic amphiphilic functional copolymer; and solvent substitution was performed to obtain a di-n-butyl ether system silane-anchored zwitterionic amphiphilic functional copolymer;

[0047] S3) Preparation of a latent amine curing agent, wherein the preparation method is as follows:

[0048] S3-1) Branched polyethyleneimine was mixed with methyl ethyl ketone and reacted at 30°C for 8 hours to obtain ketimine-blocked branched polyethyleneimine;

[0049] S3-3) The ketoimine-blocked branched polyethyleneimine obtained in S3-1 was mixed with 3-glycidyloxypropyltrimethoxysilane and reacted at 50°C for 4 h to obtain ketoimine-blocked and silanized branched polyethyleneimine.

[0050] S4) Epoxy-side-chain polysilazane resin, silane-anchored zwitterionic amphiphilic functional copolymer, latent amine curing agent, siloxane condensation crosslinking agent, tetrabutylammonium chloride and di-n-butyl ether are mixed and degassed to obtain a mixture; before use, the catalyst component containing 1,8-diazabicyclo[5.4.0]undecyl-7-ene is mixed with the mixture to obtain a room-temperature curing polysilazane coating.

[0051] Figure 1 The FTIR spectra of the silane-anchored zwitterionic amphiphilic functional copolymer provided in this embodiment are at 2955 and 2870 cm⁻¹. -1 Belongs to aliphatic -CH3 / -CH2- stretching vibrations, corresponding to lauryl side chains and alkyl segments; 1730 cm⁻¹ -1 The C=O stretching vibration of the ester group in the methacrylate structure corresponds to the ester bond in the side group of the copolymer main chain; 1250 cm⁻¹ -1 Belongs to the C–N / C–O related vibrational band, corresponding to the superposition of the β-hydroxyamine environment formed after the ring opening of the dimethylaminoethyl side chain and the contribution of the ester / ether bond; 1180 cm⁻¹ -1 With 1040cm -1 Betaine belongs to the sulfobetaine group -SO3 - The asymmetric / symmetric stretching vibrations prove that the sulfonate internal salt structure has been formed.

[0052] Example 2

[0053] This embodiment provides a high wear-resistant and stain-resistant room-temperature curing polysilazane coating and its preparation method, specifically including:

[0054] The product comprises, by weight, 100 parts of epoxy-side-coated polysilazane resin, 6 parts of silane-anchored zwitterionic amphiphilic functional copolymer, 5 parts of latent amine curing agent, 0.5 parts of siloxane condensation crosslinking agent, 1.0 part of catalyst, and 300 parts of di-n-butyl ether; wherein the catalyst comprises tetrabutylammonium chloride and 1,4-diazabicyclo[2.2.2]octane in a mass ratio of 1:1.

[0055] The epoxy-side-chain polysilazane resin is obtained by reacting the following raw materials, which, by mass, include: 100 parts of perhydropolysilazane di-n-butyl ether solution, 1 part of allyl glycidyl ether, and 0.03 parts of caster catalyst; wherein, the perhydropolysilazane di-n-butyl ether solution has a solid content of 20 wt.% and the solvent is di-n-butyl ether;

[0056] The silane-anchored zwitterionic amphiphilic functional copolymer is a copolymer obtained by free radical copolymerization, and its repeating units include: lauryl methacrylate, 2-(dimethylamino)ethyl methacrylate and 3-(trimethoxysilyl)propyl methacrylate.

[0057] The silane-anchored zwitterionic amphiphilic functional copolymer includes a sulfobetaine structure introduced by 1,3-propanesulfonyl lactone.

[0058] The latent amine curing agent is ketimine-blocked branched polyethyleneimine, which is obtained by reacting the following raw materials, comprising, by mass, 100 parts of branched polyethyleneimine and 250 parts of methyl isobutyl ketone.

[0059] The siloxane condensation crosslinking agent is methyltrimethoxysilane;

[0060] The preparation method includes the following steps:

[0061] S1) A solution of perhydropolysilazane di-n-butyl ether was mixed with a caster catalyst, and allyl glycidyl ether was added at 40°C and reacted for 6 hours. After cooling, epoxy-side-chain polysilazane resin was obtained.

[0062] S2) Lauryl methacrylate, 2-(dimethylamino)ethyl methacrylate, 3-(trimethoxysilyl)propyl methacrylate and 2,2′-azobis(2-methylpropionitrile) were added to N,N-dimethylformamide and polymerized at 75°C for 4 h to obtain a copolymer solution; 1,3-propane sulpholol was added to the copolymer solution and reacted for 12 h to obtain a silane-anchored zwitterionic amphiphilic functional copolymer; and solvent substitution was performed to obtain a di-n-butyl ether system silane-anchored zwitterionic amphiphilic functional copolymer;

[0063] S3) Preparation of a latent amine curing agent, wherein the preparation includes:

[0064] S3-1) Branched polyethyleneimine was mixed with methyl isobutyl ketone and reacted at 45°C for 5 hours to obtain ketimine-blocked branched polyethyleneimine.

[0065] S4) Epoxy-side-group polysilazane resin, silane-anchored zwitterionic amphiphilic functional copolymer, latent amine curing agent, siloxane condensation crosslinking agent, tetrabutylammonium chloride and di-n-butyl ether are mixed and degassed to obtain a mixture; before use, a catalyst component containing 1,4-diazabicyclo[2.2.2]octane is mixed with the mixture to obtain a room-temperature curing polysilazane coating.

[0066] Example 3

[0067] This embodiment provides a high wear-resistant and stain-resistant room-temperature curing polysilazane coating and its preparation method, specifically including:

[0068] The product comprises, by weight, 100 parts of epoxy-side-coated polysilazane resin, 3.5 parts of silane-anchored zwitterionic amphiphilic functional copolymer, 15 parts of latent amine curing agent, 20 parts of siloxane condensation crosslinking agent, 0.8 parts of catalyst, and 50 parts of di-n-butyl ether; wherein the catalyst comprises tetrabutylammonium chloride and 1,8-diazabicyclo[5.4.0]undecyl-7-ene in a mass ratio of 1:1.

[0069] The epoxy-side-chain polysilazane resin is obtained by reacting the following raw materials, which, by mass, include: 100 parts of perhydropolysilazane di-n-butyl ether solution, 4 parts of allyl glycidyl ether, and 0.05 parts of caster catalyst; wherein, the perhydropolysilazane di-n-butyl ether solution has a solid content of 20 wt.% and the solvent is di-n-butyl ether;

[0070] The silane-anchored zwitterionic amphiphilic functional copolymer is a copolymer obtained by free radical copolymerization, and its repeating units include: lauryl methacrylate, 2-(dimethylamino)ethyl methacrylate and 3-(trimethoxysilyl)propyl methacrylate.

[0071] The silane-anchored zwitterionic amphiphilic functional copolymer includes a sulfobetaine structure introduced by 1,3-propanesulfonyl lactone.

[0072] The latent amine curing agent is silanized branched polyethyleneimine, which is obtained by reacting the following raw materials, comprising, by mass: 100 parts of branched polyethyleneimine and 5 parts of 3-glycidyloxypropyltrimethoxysilane.

[0073] The siloxane condensation crosslinking agent is 3-glycidyloxypropyltrimethoxysilane;

[0074] The preparation method includes the following steps:

[0075] S1) A solution of perhydropolysilazane di-n-butyl ether was mixed with a caster catalyst, and allyl glycidyl ether was added at 50°C and reacted for 4 hours. After cooling, epoxy-side-chain polysilazane resin was obtained.

[0076] S2) Lauryl methacrylate, 2-(dimethylamino)ethyl methacrylate, 3-(trimethoxysilyl)propyl methacrylate and 2,2′-azobis(2-methylpropionitrile) were added to N,N-dimethylformamide and polymerized at 70°C for 8 h to obtain a copolymer solution; 1,3-propane sulpholol was added to the copolymer solution and reacted for 8 h to obtain a silane-anchored zwitterionic amphiphilic functional copolymer; and solvent substitution was performed to obtain a di-n-butyl ether system silane-anchored zwitterionic amphiphilic functional copolymer;

[0077] S3) Preparation of a latent amine curing agent, wherein the preparation includes:

[0078] S3-2) Branched polyethyleneimine was mixed with 3-glycidyloxypropyltrimethoxysilane and reacted at 40°C for 6 h to obtain silanized branched polyethyleneimine.

[0079] S4) Epoxy-side-group polysilazane resin, silane-anchored zwitterionic amphiphilic functional copolymer, latent amine curing agent, siloxane condensation crosslinking agent, tetrabutylammonium chloride and di-n-butyl ether are mixed and degassed to obtain a mixture; before use, the catalyst component containing 1,8-diazabicyclo[5.4.0]undecyl-7-ene is mixed with the mixture to obtain a room-temperature curing polysilazane coating.

[0080] Example 4

[0081] This embodiment provides a high wear-resistant and stain-resistant room-temperature curing polysilazane coating and its preparation method, specifically including:

[0082] The product comprises, by weight, 100 parts of epoxy-side-group polysilazane resin, 4 parts of silane-anchored zwitterionic amphiphilic functional copolymer, 20 parts of latent amine curing agent, 5 parts of siloxane condensation crosslinking agent, 1.50 parts of catalyst, and 150 parts of di-n-butyl ether; wherein the catalyst comprises tetrabutylammonium chloride, 1,8-diazabicyclo[5.4.0]undecyl-7-ene and 1,4-diazabicyclo[2.2.2]octane in a mass ratio of 1:0.5:0.5.

[0083] The epoxy-side-chain polysilazane resin is obtained by reacting the following raw materials, which, by mass, include: 100 parts of perhydropolysilazane di-n-butyl ether solution, 6 parts of allyl glycidyl ether, and 0.02 parts of caster catalyst; wherein, the perhydropolysilazane di-n-butyl ether solution has a solid content of 20 wt.% and the solvent is di-n-butyl ether;

[0084] The silane-anchored zwitterionic amphiphilic functional copolymer is a copolymer obtained by free radical copolymerization, and its repeating units include: lauryl methacrylate, 2-(dimethylamino)ethyl methacrylate and 3-(trimethoxysilyl)propyl methacrylate.

[0085] The silane-anchored zwitterionic amphiphilic functional copolymer includes a sulfobetaine structure introduced by 1,3-propanesulfonyl lactone.

[0086] The latent amine curing agent is a branched polyethyleneimine blocked and silanized with ketimine, which is obtained by reacting the following raw materials, comprising, by mass: 100 parts of branched polyethyleneimine, 150 parts of methyl ethyl ketone, and 40 parts of 3-glycidyloxypropyltrimethoxysilane.

[0087] The siloxane condensation crosslinking agent is a mixture of tetraethoxysilane and methyltrimethoxysilane;

[0088] The preparation method includes the following steps:

[0089] S1) A solution of perhydropolysilazane di-n-butyl ether was mixed with a caster catalyst, and allyl glycidyl ether was added at 55°C and reacted for 3 hours. After cooling, epoxy-side-chain polysilazane resin was obtained.

[0090] S2) Lauryl methacrylate, 2-(dimethylamino)ethyl methacrylate, 3-(trimethoxysilyl)propyl methacrylate and 2,2′-azobis(2-methylpropionitrile) were added to N,N-dimethylformamide and polymerized at 72°C for 6 h to obtain a copolymer solution; 1,3-propane sulpholol was added to the copolymer solution and reacted for 10 h to obtain a silane-anchored zwitterionic amphiphilic functional copolymer; and solvent substitution was performed to obtain a di-n-butyl ether system silane-anchored zwitterionic amphiphilic functional copolymer;

[0091] S3) Preparation of a latent amine curing agent, wherein the preparation includes:

[0092] S3-1) Branched polyethyleneimine was mixed with methyl ethyl ketone and reacted at 40°C for 7 h to obtain ketimine-blocked branched polyethyleneimine;

[0093] S3-3) The ketoimine-blocked branched polyethyleneimine obtained in S3-1 was mixed with 3-glycidyloxypropyltrimethoxysilane and reacted at 45°C for 3 h to obtain ketoimine-blocked and silanized branched polyethyleneimine.

[0094] S4) Epoxy-side-group polysilazane resin, silane-anchored zwitterionic amphiphilic functional copolymer, latent amine curing agent, siloxane condensation crosslinking agent, tetrabutylammonium chloride and di-n-butyl ether are mixed and degassed to obtain a mixture; before use, a catalyst component containing 1,8-diazabicyclo[5.4.0]undec-7-ene and 1,4-diazabicyclo[2.2.2]octane is mixed with the mixture to obtain a room-temperature curing polysilazane coating.

[0095] Comparative Example 1

[0096] This comparative example provides a room-temperature curing polysilazane coating with high wear resistance and antifouling properties and its preparation method. The difference between this and Example 1 is that the mass fraction of the silane-anchored zwitterionic amphiphilic functional copolymer in S4 is 0, while other process parameters and operating conditions are exactly the same as in Example 1.

[0097] Comparative Example 2

[0098] This comparative example provides a room-temperature curing polysilazane coating with high wear resistance and antifouling properties and its preparation method. The difference between this and Example 1 is that the silane-anchored zwitterionic amphiphilic functional copolymer in S4 is replaced with an amphiphilic copolymer that has not reacted with 1,3-propane sulfonyl lactone. Other process parameters and operating conditions are exactly the same as in Example 1.

[0099] Comparative Example 3

[0100] This comparative example provides a room-temperature curing polysilazane coating with high wear resistance and antifouling properties and its preparation method. The difference between this and Example 1 is that the raw materials for preparing the amphiphilic copolymer in S2 do not contain 3-(trimethoxysilyl)methacrylate, and the functional copolymer added in S4 is an amphoteric amphiphilic functional copolymer without silane anchoring units. Other process parameters and operating conditions are exactly the same as in Example 1.

[0101] Comparative Example 4

[0102] This comparative example provides a room-temperature curing polysilazane coating with high wear resistance and anti-fouling properties and its preparation method. The difference between this and Example 1 is that the latent amine curing agent in S4 is replaced with branched polyethyleneimine, while other process parameters and operating conditions are exactly the same as in Example 1.

[0103] After the obtained coating is applied to the substrate surface to form a film, it is placed in a clean, ventilated environment to allow it to level. Then, it is allowed to stand at room temperature to evaporate the solvent and come into contact with air moisture. The coated sample is dried at 30-35℃ for 10-12 hours, and then cured in an environment of 20-30℃ and 40-70% relative humidity for 24-72 hours. After curing, a cured coating film is obtained. If the ambient humidity is lower than the above range, a water tray should be placed in a sealed curing chamber and air circulation maintained. During curing and ripening, the coating surface should avoid direct contact with liquid water or being wiped.

[0104] The abrasion resistance test method is ASTM D4060, and the evaluation index is the mass loss before and after abrasion, with the unit being mg.

[0105] The stain resistance test method is ASTM D4828, and the evaluation index is the color difference of the residual stains after cleaning, with the unit being dimensionless.

[0106] The adhesion test method is GB / T 9286.

[0107] The test results are shown in Table 1.

[0108] Table 1. Test results of room temperature curing polysilazane coatings from Examples 1-4 and Comparative Examples 1-4

[0109]

[0110] As shown in Table 1, compared with Example 1, Comparative Example 1 showed increased mass loss and color difference; Comparative Example 2 showed increased mass loss and color difference; Comparative Example 3 showed increased mass loss and color difference, but decreased adhesion; and Comparative Example 4 showed increased mass loss, increased color difference, and decreased adhesion.

[0111] This is because, in Comparative Example 1, after removing the zwitterionic amphiphilic copolymer, the surface lacks a sulfobetaine hydration layer, allowing for more thorough contact between the stain and the organic phase. Simultaneously, the absence of silane-anchored co-condensation nodes reduces surface crosslinking density, increases abrasion, and leads to increased residue after cleaning. In Comparative Example 2, the functional copolymer, lacking sulfonyl lactone quaternization, has only tertiary amine side chains, making it difficult to form a stable internal saline hydration interface, hindering the maintenance of a continuous water film during cleaning. Although silane sites can be co-condensed and fixed, insufficient surface energy control reduces stain removal and increases abrasion. In Comparative Example 3, the zwitterionic copolymer lacks trimethoxysilane anchoring units, making it prone to migration and embedding during film formation, or being carried away by cleaning after surface enrichment. The interface layer is difficult to lock into the silicon-oxygen network, resulting in microphase separation and surface defects, decreased antifouling durability, reduced abrasion resistance, and decreased adhesion. In Comparative Example 4, when unclosed branched polyethyleneimine was used to replace the latent amine, the ring-opening reaction of the amine with the epoxy proceeded rapidly in the early stage of mixing. The system became thickened in advance and formed local gels. The solvent evaporation and condensation reaction were unevenly fixed, resulting in increased porosity and internal stress, and a decrease in wear resistance, stain resistance and adhesion.

[0112] The above description is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention fall within the protection and disclosure scope of the present invention.

Claims

1. A highly wear-resistant and stain-resistant room-temperature curing polysilazane coating, characterized in that, The product comprises, by weight, 100 parts of epoxy-side-coated polysilazane resin, 1-6 parts of silane-anchored zwitterionic amphiphilic functional copolymer, 5-30 parts of latent amine curing agent, 0.5-20 parts of siloxane condensation crosslinking agent, 0.05-1.50 parts of catalyst, and 50-300 parts of di-n-butyl ether; wherein the catalyst comprises at least tetrabutylammonium chloride.

2. The high wear-resistant and stain-resistant room-temperature curing polysilazane coating according to claim 1, characterized in that, The epoxy-side-chain polysilazane resin is obtained by reacting the following raw materials, which, by mass, include: 100 parts of a di-n-butyl ether solution of perhydropolysilazane, 1-8 parts of allyl glycidyl ether, and 0.005-0.050 parts of caster catalyst; wherein, the solid content of the di-n-butyl ether solution of perhydropolysilazane is 20 wt.%, and the solvent is di-n-butyl ether.

3. The high wear-resistant and stain-resistant room-temperature curing polysilazane coating according to claim 1, characterized in that, The silane-anchored zwitterionic amphiphilic functional copolymer is a copolymer obtained by free radical copolymerization, and its repeating units include lauryl methacrylate, 2-(dimethylamino)ethyl methacrylate and 3-(trimethoxysilyl)propyl methacrylate.

4. The high wear-resistant and stain-resistant room-temperature curing polysilazane coating according to claim 3, characterized in that, The silane-anchored zwitterionic amphiphilic functional copolymer includes a sulfobetaine structure introduced by 1,3-propanesulfonyl lactone.

5. The high wear-resistant and stain-resistant room-temperature curing polysilazane coating according to claim 1, characterized in that, The latent amine curing agent is any one of ketimide-blocked branched polyethyleneimine, silanized branched polyethyleneimine, or ketimide-blocked and silanized branched polyethyleneimine. The ketimine-blocked branched polyethyleneimine is prepared by reacting branched polyethyleneimine with methyl ethyl ketone or methyl isobutyl ketone; The silanized branched polyethyleneimine is prepared by a ring-opening addition reaction of branched polyethyleneimine and 3-glycidoxypropyltrimethoxysilane; The ketoimine-blocked and silanized branched polyethyleneimine is prepared by reacting branched polyethyleneimine, methyl ethyl ketone or methyl isobutyl ketone with 3-glycidoxypropyltrimethoxysilane.

6. The high wear-resistant and stain-resistant room-temperature curing polysilazane coating according to claim 1, characterized in that, The siloxane condensation crosslinking agent is one or more of tetraethoxysilane, methyltrimethoxysilane, and 3-glycidoxypropyltrimethoxysilane; the catalyst, in addition to tetrabutylammonium chloride, also includes one or two of 1,8-diazabicyclo[5.4.0]undec-7-ene or 1,4-diazabicyclo[2.2.2]octane; the 1,8-diazabicyclo[5.4.0]undec-7-ene is packaged separately from the other components and mixed with the other components before use.

7. A method for preparing a high-wear-resistant and anti-fouling room-temperature curing polysilazane coating as described in any one of claims 1-6, characterized in that, Includes the following steps: A solution of perhydropolysilazane di-n-butyl ether, a cassiterite catalyst and allyl glycidyl ether were mixed and reacted to obtain epoxy-side-group polysilazane resin. Lauryl methacrylate, 2-(dimethylamino)ethyl methacrylate, 3-(trimethoxysilyl)propyl methacrylate, and 2,2′-azobis(2-methylpropionitrile) were added to N,N-dimethylformamide and reacted to obtain a copolymer solution. 1,3-propane sulpholactone was added to the copolymer solution to react and obtain a silane-anchored zwitterionic amphiphilic functional copolymer. Solvent substitution was then performed to obtain a di-n-butyl ether-based silane-anchored zwitterionic amphiphilic functional copolymer. An epoxy-side-chain polysilazane resin, a silane-anchored zwitterionic amphiphilic functional copolymer, a latent amine curing agent, a siloxane condensation crosslinking agent, tetrabutylammonium chloride, and di-n-butyl ether are mixed and degassed to obtain a mixture. When used, a catalyst component containing 1,8-diazabicyclo[5.4.0]undecyl-7-ene is mixed with the mixture to obtain a room-temperature curing polysilazane coating.

8. The method for preparing a high-wear-resistant and anti-fouling room-temperature curing polysilazane coating according to claim 7, characterized in that, The preparation method of the latent amine curing agent includes any one or more of the following: Branched polyethyleneimine is mixed with methyl ethyl ketone or methyl isobutyl ketone and reacted to obtain ketimine-blocked branched polyethyleneimine; Branched polyethyleneimine was mixed with 3-glycidoxypropyltrimethoxysilane and reacted to obtain silanized branched polyethyleneimine; The obtained ketimine-blocked branched polyethyleneimine was mixed and reacted with 3-glycidyloxypropyltrimethoxysilane to obtain ketimine-blocked and silanized branched polyethyleneimine.

9. The method for preparing a high-wear-resistant and anti-fouling room-temperature curing polysilazane coating according to claim 8, characterized in that, In the preparation of the ketimine-blocked branched polyethyleneimine, by mass parts: 100 parts of branched polyethyleneimine, and 50-250 parts of methyl ethyl ketone or methyl isobutyl ketone; In the preparation of the silanized branched polyethyleneimine, by mass parts: 100 parts of branched polyethyleneimine and 5-80 parts of 3-glycidyloxypropyltrimethoxysilane; In the preparation of the ketoimine-blocked and silanized branched polyethyleneimine, by mass parts: 100 parts branched polyethyleneimine, 50-250 parts methyl ethyl ketone or methyl isobutyl ketone, and 5-80 parts 3-glycidoxypropyltrimethoxysilane.

10. The application of a room-temperature curing polysilazane coating with high wear resistance and antifouling properties as described in any one of claims 1-6 in the field of wear resistance and antifouling.

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