High-toughness and high-strength finishing coating and preparation method thereof

Abstract

The invention discloses a high-toughness and high-strength finishing coating and a preparation method thereof. The invention further discloses the high-toughness and high-strength finishing coating and the preparation method thereof. The coating comprises a main agent, a curing agent and a diluent, the main agent comprises a film forming component composed of elastic resin and 35% cellulose nitrate resin and matting powder, and the matting powder is fumed silica; the curing agent is aliphatic isocyanate and butyl acetate; the diluent comprises xylene, butyl acetate and propylene glycol; the problem that bright marks appear when fingernails, hard objects and the like are scratched by existing paint is solved.

Description

Technical Field

[0001] This invention relates to the field of furniture protective coating technology, specifically, to a high-toughness, high-strength topcoat coating and its preparation method. Background Technology

[0002] As people's material and cultural living standards improve, consumers are demanding higher and higher quality finishes from furniture manufacturers. In an increasingly competitive environment, furniture factories are striving to improve product quality, achieve breakthroughs in performance, and identify highlights and selling points for various coating finishes to enhance product competitiveness and added value.

[0003] Traditional polyurethane transparent topcoat materials fail to form an effective dense paint film due to insufficient cross-linking density, toughness, and hardness. Ordinary matte materials float on the surface of the paint film, causing glossy marks to appear on panels with lower gloss after being scratched by hard objects. These marks are irreversible and severely affect the aesthetic appearance of the furniture during use.

[0004] Therefore, a decorative material that is both hard and tough is needed to solve this problem. Summary of the Invention

[0005] The purpose of this invention is to provide a high-toughness, high-strength topcoat coating and its preparation method, so as to solve the problem of glossy marks appearing when existing coatings are scratched by fingernails, hard objects, etc.

[0006] To solve the above problems, the present invention employs the following technical means: A high-toughness, high-strength topcoat includes a base agent, a curing agent, and a diluent; The main agent includes a film-forming component composed of elastic resin and 35% nitrocellulose resin, and a matting agent, wherein the matting agent is fumed silica. The curing agent is an aliphatic isocyanate and butyl acetate; The diluents include xylene, butyl acetate, and propylene glycol.

[0007] A composite system of 35% elastic resin and nitrocellulose resin, combined with an aliphatic isocyanate curing agent, forms a paint film structure that combines rigidity and toughness. The elastic resin provides high toughness and a smooth, elastic feel, preventing brittle cracking of the paint film; the nitrocellulose resin aids in rapid drying and enhances hardness; and the aliphatic curing agent reacts with the resin to form a highly cross-linked paint film, while maintaining weather resistance and toughness.

[0008] The long-chain, flexible elastic resin is capable of reversible stretching and contraction when its segments are stressed. After curing, it forms a continuous, flexible three-dimensional network. When subjected to scratches or impacts, this elastic three-dimensional network absorbs and disperses impact energy through its own deformation. Combined with 35% nitrocellulose resin, it provides initial hardness, sandability, and rapid drying; its intertwining with the elastic resin provides a rigid framework in the early stages of curing, compensating for the elastic resin's relatively softness; simultaneously, it significantly accelerates the surface drying speed of the paint film, improving application efficiency.

[0009] Furthermore, a specific curing process allows for the simultaneous attainment of both increased hardness and high toughness resulting from high crosslinking density. The curing agent utilizes the inherent flexibility of its hexamethylene molecular chains. Unlike the more brittle aromatic isocyanates, it allows for bending and rotation of its chain segments while forming strong carbamate bonds. The elastic resin provides ultra-long, flexible chains as a backbone. The curing agent, acting as high-strength active nodes, tightly connects these flexible backbones. The resulting paint film network possesses both the hardness and strength provided by the high-density active nodes, while retaining the excellent toughness and elastic recovery capabilities of the flexible backbone.

[0010] Furthermore, the curing agent used in this application utilizes a high-crosslink density network formed by aliphatic isocyanates to firmly anchor the matting powder throughout the entire coating system. Specifically, the rapidly formed dense network restricts the migration and settling of the matting powder, ensuring its uniform distribution. Thus, the surface of the coating is actually composed of a tough resin-curing agent crosslinking network, rather than a fragile matting powder buildup. When scratched, it is this tough network that provides resistance, not the surface matting powder. Therefore, even with extremely low gloss, it possesses extremely high surface scratch resistance.

[0011] Furthermore, the thinner is crucial for achieving scratch resistance while maintaining a low gloss finish. A well-blended thinner allows sufficient time for the matting agents to align evenly and stably within the paint film, rather than floating on the surface or settling at the bottom. This ultimately results in a dense structure where the matting agents are evenly distributed throughout the entire paint film phase.

[0012] Preferably, by weight, the main agent comprises 25-30 parts of elastic resin, 15-25 parts of 35% nitrocellulose resin, 25-35 parts of butyl acetate, 3-8 parts of xylene, 2-10 parts of propylene glycol methyl ether acetate, 1-2 parts of defoamer, 0.3-0.5 parts of drying agent, 0.5-1 part of leveling agent, and 0.5 parts of anti-settling agent; The curing agent comprises 40-50 parts of aliphatic isocyanate and 50-60 parts of butyl acetate; The diluent includes 15-25 parts xylene, 40-60 parts butyl acetate, and propylene glycol methyl ether acetate.

[0013] Furthermore, the defoamer is a modified silicone defoamer.

[0014] Furthermore, the anti-settling agent is a polyamide wax.

[0015] Furthermore, the drying agent is an organotin drying agent.

[0016] Furthermore, the leveling agent is an organosilicon-based leveling agent.

[0017] Furthermore, the dispersant is a deflocculating dispersant.

[0018] In addition, a method for preparing the aforementioned high-toughness, high-strength topcoat includes, The main agent is prepared according to the following preparation method: After mixing the elastic resin, 35% nitrocellulose resin, propylene glycol methyl ether acetate, xylene, butyl acetate, anti-settling agent, defoamer, and dispersant, disperse the mixture at 600-800 rpm for 5-8 minutes until the mixture is homogeneous. Then add the matting agent and disperse at 1000-1500 rpm for 15 minutes until the dispersion fineness is <40um; After adding butyl acetate, drier, and leveling agent, disperse at 600-800 rpm for 5-8 minutes until the mixture is homogeneous; The diluent is prepared according to the following method: After mixing xylene, butyl acetate and propylene glycol methyl ether acetate, disperse the mixture at 300-700 rpm for 3-8 minutes until the mixture is homogeneous. The curing agent is prepared according to the following preparation method: After mixing aliphatic isocyanate and butyl acetate, disperse at 300-700 rpm for 3-8 minutes until the mixture is homogeneous; The main agent, the curing agent, and the diluent are mixed in a ratio of 1:0.35 to 0.5:0.1, and the finished coating is obtained after curing.

[0019] Furthermore, the main agent is filtered and packaged after preparation using a 200-mesh filter, the diluent is filtered and packaged using a 300-mesh filter, and the curing agent is filtered and packaged using a 300-mesh filter.

[0020] The present invention has the following beneficial effects when used: This invention can be applied to matte panels where high scratch resistance is required. It is particularly suitable for ultra-matte finishes that do not leave glossy marks after being scratched by fingernails or hard objects. Compared to traditional polyurethane matte finishes, the coating film exhibits significantly improved resistance to gloss marks and scratches. The coating involved in this invention has excellent toughness and a skin-like elasticity, feeling similar to fleshy skin to the touch. The coating film has a higher cross-linking density than conventional finishes, exhibiting superior chemical resistance and other properties; it is both tough and hard, making it difficult for hard objects to scratch or break it. Detailed Implementation

[0021] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0022] Therefore, the following detailed description of embodiments of the present invention is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0023] It should be noted that, unless otherwise specified, the embodiments and features described in this invention can be combined with each other.

[0024] A high-toughness, high-strength topcoat includes a base agent, a curing agent, and a diluent; The main agent includes a film-forming component composed of elastic resin and 35% nitrocellulose resin, and a matting agent, wherein the matting agent is fumed silica. The curing agent is an aliphatic isocyanate and butyl acetate; The diluents include xylene, butyl acetate, and propylene glycol.

[0025] A composite system of 35% elastic resin and nitrocellulose resin, combined with an aliphatic isocyanate curing agent, forms a paint film structure that combines rigidity and toughness. The elastic resin provides high toughness and a smooth, elastic feel, preventing brittle cracking of the paint film; the nitrocellulose resin aids in rapid drying and enhances hardness; and the aliphatic curing agent reacts with the resin to form a highly cross-linked paint film, while maintaining weather resistance and toughness.

[0026] The long-chain, flexible elastic resin is capable of reversible stretching and contraction when its segments are stressed. After curing, it forms a continuous, flexible three-dimensional network. When subjected to scratches or impacts, this elastic three-dimensional network absorbs and disperses impact energy through its own deformation. Combined with 35% nitrocellulose resin, it provides initial hardness, sandability, and rapid drying; its intertwining with the elastic resin provides a rigid framework in the early stages of curing, compensating for the elastic resin's relatively softness; simultaneously, it significantly accelerates the surface drying speed of the paint film, improving application efficiency.

[0027] Furthermore, a specific curing process allows for the simultaneous attainment of both increased hardness and high toughness resulting from high crosslinking density. The curing agent utilizes the inherent flexibility of its hexamethylene molecular chains. Unlike the more brittle aromatic isocyanates, it allows for bending and rotation of its chain segments while forming strong carbamate bonds. The elastic resin provides ultra-long, flexible chains as a backbone. The curing agent, acting as high-strength active nodes, tightly connects these flexible backbones. The resulting paint film network possesses both the hardness and strength provided by the high-density active nodes, while retaining the excellent toughness and elastic recovery capabilities of the flexible backbone.

[0028] Furthermore, the curing agent used in this application utilizes a high-crosslink density network formed by aliphatic isocyanates to firmly anchor the matting powder throughout the entire coating system. Specifically, the rapidly formed dense network restricts the migration and settling of the matting powder, ensuring its uniform distribution. Thus, the surface of the coating is actually composed of a tough resin-curing agent crosslinking network, rather than a fragile matting powder buildup. When scratched, it is this tough network that provides resistance, not the surface matting powder. Therefore, even with extremely low gloss, it possesses extremely high surface scratch resistance.

[0029] Furthermore, the thinner is crucial for achieving scratch resistance while maintaining a low gloss finish. A well-blended thinner allows sufficient time for the matting agents to align evenly and stably within the paint film, rather than floating on the surface or settling at the bottom. This ultimately results in a dense structure where the matting agents are evenly distributed throughout the entire paint film phase.

[0030] Furthermore, the defoamer is a modified silicone defoamer.

[0031] Furthermore, the anti-settling agent is a polyamide wax.

[0032] Furthermore, the drying agent is an organotin drying agent.

[0033] Furthermore, the leveling agent is an organosilicon-based leveling agent.

[0034] Furthermore, the dispersant is a deflocculating dispersant.

[0035] In addition, a method for preparing the aforementioned high-toughness, high-strength topcoat includes, The main agent is prepared according to the following preparation method: After mixing the elastic resin, 35% nitrocellulose resin, propylene glycol methyl ether acetate, xylene, butyl acetate, anti-settling agent, defoamer, and dispersant, disperse the mixture at 600-800 rpm for 5-8 minutes until the mixture is homogeneous. Then add the matting agent and disperse at 1000-1500 rpm for 15 minutes until the dispersion fineness is <40um; After adding butyl acetate, drier, and leveling agent, disperse at 600-800 rpm for 5-8 minutes until the mixture is homogeneous; The diluent is prepared according to the following method: After mixing xylene, butyl acetate and propylene glycol methyl ether acetate, disperse the mixture at 300-700 rpm for 3-8 minutes until the mixture is homogeneous. The curing agent is prepared according to the following preparation method: After mixing aliphatic isocyanate and butyl acetate, disperse at 300-700 rpm for 3-8 minutes until the mixture is homogeneous; The main agent, the curing agent, and the diluent are mixed in a ratio of 1:0.35 to 0.5:0.1, and the finished coating is obtained after curing.

[0036] Furthermore, the main agent is filtered and packaged after preparation using a 200-mesh filter, the diluent is filtered and packaged using a 300-mesh filter, and the curing agent is filtered and packaged using a 300-mesh filter.

[0037] The main agent in several embodiments of this application uses the components and dosages shown in the table below: project Product Category Raw material grade Example 1 Example 2 Example 3 1 elastic resin Zuoronggong 18# 29 29 29 2 35% Nitrocellulose Resin Sogo 1 / 2 20 21.5 22.5 3 dispersant EFKA4010 1.5 1.5 1.5 4 Defoamer BYK141 0.4 0.4 0.4 5 Anti-settling agent HX-8800 0.5 0.5 0.5 6 Propylene glycol methyl ether acetate PMA 3 3 3 7 xylene xylene 4 4 4 8 Butyl acetate Butyl acetate 10 10 10 9 Matte powder ACEMATT3400 5.5 4 3 10 Leveling agent TEGO450 0.2 0.2 0.2 11 Leveling agent HX-3130 0.2 0.2 0.2 12 Organosilicon surface additives BYK-3700 0.3 0.3 0.3 13 drying agent T-12 0.4 0.4 0.4 14 Butyl acetate Butyl acetate 25 25 25 The curing agent used in several embodiments of this application adopts the components and dosages shown in the table below: project Product Category Raw material grade Dosage 1 Aliphatic HDI Wanhua HT-100plus 45 2 solvent Butyl acetate 55 The diluents used in several embodiments of this application employ the components and amounts shown in the table below: project Product Category Raw material grade Dosage 1 solvent xylene 25 2 solvent Butyl acetate 45 3 solvent Propylene glycol methyl ether acetate 30 Preparation process: A high-toughness and high-strength topcoat material is prepared by mixing the main agent, curing agent and diluent in a weight ratio of 1:0.35:0.1. The main agent is prepared according to the following method: After mixing the elastic resin, 35% nitrocellulose resin, propylene glycol methyl ether acetate, xylene, butyl acetate, anti-settling agent, defoamer, and dispersant, disperse the mixture at 600-800 rpm for 5-8 minutes until the mixture is homogeneous. Then add the matting agent and disperse at 1000-1500 rpm for 15 minutes until the dispersion fineness is <40um; After adding 0.7 parts of butyl acetate, drier, and leveling agent, disperse at 600-800 rpm for 5-8 minutes until the mixture is homogeneous; The diluent is prepared according to the following method: After mixing xylene, butyl acetate, and propylene glycol methyl ether acetate, disperse the mixture at 300-700 rpm for 3-8 minutes until the mixture is homogeneous. The curing agent is prepared according to the following method: After mixing aliphatic isocyanate and butyl acetate, disperse the mixture at 300-700 rpm for 3-8 minutes until the mixture is homogeneous.

[0038] After the main agent is prepared, it is filtered and packaged using a 200-mesh filter; after the diluent is prepared, it is filtered and packaged using a 300-mesh filter; after the curing agent is prepared, it is filtered and packaged using a 300-mesh filter.

[0039] Based on tests of various embodiments, the performance and technical indicators of this high-toughness and high-strength topcoat material are shown in the following tables: Table 1 shows the technical performance indicators and experimental data of various embodiments of the high-toughness and high-strength topcoat material provided by the present invention:

[0040] As can be clearly seen from Table 1, the technical performance of each embodiment of the high-toughness and high-strength topcoat material provided by the present invention meets or exceeds the technical indicators in the national standard GB / T23997-2009.

[0041] Table 2 presents the environmental protection test data for various embodiments of the high-toughness and high-strength topcoat material provided by this invention:

[0042] As can be clearly seen from Table 2, the VOCs (volatile organic compounds) and soluble heavy metals contained in the various embodiments and comparative examples of the present invention are all superior to the GB18581-2020 standard, meet environmental and health requirements, and are safe and reliable to use.

[0043] The curing agent of the high-toughness and high-strength topcoat material provided by this invention is aliphatic. This curing agent has excellent weather resistance, toughness, hardness and other properties, and can greatly improve the coating performance when used in combination.

[0044] Application process: Red oak open-face veneer board - sanding the raw material - applying base coat - drying - acrylic open-face primer - drying for 24 hours - sanding smooth with 400# or higher grit - spraying the example topcoat and conventional polyurethane open-face matte clear topcoat.

[0045] Table 3 shows the various embodiments of the high-toughness and high-strength topcoat material provided by the present invention and comparative examples with conventional methods. After the above process was used to prepare the plates on the red oak open substrate, the performance of each component was tested:

[0046] As can be clearly seen from Table 3, the experimental data on the abrasion resistance of the paint films in the various embodiments and comparative examples of the present invention all meet or exceed the technical indicators in the national standard GB / T23997-2009. The abrasion resistance, nail scratch resistance, and paint knife scratch resistance are significantly better than those of the conventional polyurethane clear topcoat in the comparative example.

[0047] Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A high-toughness, high-strength topcoat, characterized in that, Includes main agent, curing agent and diluent; The main agent includes a film-forming component composed of elastic resin and 35% nitrocellulose resin, and a matting agent, wherein the matting agent is fumed silica. The curing agent is an aliphatic isocyanate and butyl acetate; The diluents include xylene, butyl acetate, and propylene glycol.

2. The high-toughness, high-strength topcoat according to claim 1, characterized in that, By weight, the main component comprises 25-30 parts of elastic resin, 15-25 parts of 35% nitrocellulose resin, 25-35 parts of butyl acetate, 3-8 parts of xylene, 2-10 parts of propylene glycol methyl ether acetate, 1-2 parts of defoamer, 0.3-0.5 parts of drying agent, 0.5-1 part of leveling agent, and 0.5 parts of anti-settling agent; The curing agent comprises 40-50 parts of aliphatic isocyanate and 50-60 parts of butyl acetate; The diluent includes 15-25 parts xylene, 40-60 parts butyl acetate, and propylene glycol methyl ether acetate.

3. The high-toughness, high-strength topcoat according to claim 2, characterized in that, The defoamer used is a modified silicone defoamer.

4. The high-toughness, high-strength topcoat according to claim 2, characterized in that, The anti-settling agent is polyamide wax.

5. The high-toughness, high-strength topcoat according to claim 2, characterized in that, The drying agent mentioned is an organotin drying agent.

6. The high-toughness, high-strength topcoat according to claim 2, characterized in that, The leveling agent used is an organosilicon-based leveling agent.

7. The high-toughness, high-strength topcoat according to claim 2, characterized in that, The dispersant used is a deflocculating dispersant.

8. A method for preparing a high-toughness, high-strength topcoat according to any one of claims 2 to 7, characterized in that, The main agent is prepared according to the following preparation method: After mixing the elastic resin, 35% nitrocellulose resin, propylene glycol methyl ether acetate, xylene, butyl acetate, anti-settling agent, defoamer, and dispersant, disperse the mixture at 600-800 rpm for 5-8 minutes until the mixture is homogeneous. Then add the matting agent and disperse at 1000-1500 rpm for 15 minutes until the dispersion fineness is <40um; After adding butyl acetate, drier, and leveling agent, disperse at 600-800 rpm for 5-8 minutes until the mixture is homogeneous; The diluent is prepared according to the following method: After mixing xylene, butyl acetate and propylene glycol methyl ether acetate, disperse the mixture at 300-700 rpm for 3-8 minutes until the mixture is homogeneous. The curing agent is prepared according to the following preparation method: After mixing aliphatic isocyanate and butyl acetate, disperse at 300-700 rpm for 3-8 minutes until the mixture is homogeneous; The main agent, the curing agent, and the diluent are mixed in a ratio of 1:0.35 to 0.5:0.1, and the finished coating is obtained after curing.

9. The preparation method according to claim 8, characterized in that, The main agent is filtered and packaged after preparation using a 200-mesh filter, the diluent is filtered and packaged using a 300-mesh filter, and the curing agent is filtered and packaged using a 300-mesh filter.

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