Solvent-free super-wear-resistant polyurethane floor coating and preparation method thereof

Abstract

The invention relates to a solvent-free super-wear-resistant polyurethane floor coating and a preparation method thereof. The solvent-free super-wear-resistant polyurethane floor coating comprises a component A, a component B and a component C, the component A is prepared from a mixture of a hexamethylene diisocyanate tripolymer, an isophorone isocyanate tripolymer and uretdione isocyanate, and a siloxane coupling agent; the component B comprises bio-based polyol resin, a polyisocyanate copolymerization reactant containing amino functional groups, a wear-resistant filler, titanium dioxide, a rheological additive, a dispersing agent, a defoaming agent, a flatting agent, a catalyst and a scratch-resistant additive; and the component C comprises wear-resistant aggregate and a dehydrating agent. According to the solvent-free super-wear-resistant polyurethane floor coating disclosed by the invention, a paint film has extremely high hardness (pencil hardness 6H), super-strong wear resistance (wear resistance 8mg), excellent weather resistance (artificial weathering aging resistance reaches 1000h), safe and reliable high skid resistance (wet friction coefficient is greater than or equal to 0.77) and excellent scratch resistance.

Description

Technical Field

[0001] The invention belongs to the technical field of polyurethane materials, and in particular relates to a solvent-free super-wear-resistant polyurethane floor coating and a preparation method thereof. Background Art

[0002] The most commonly used floor coating at present is solvent-free epoxy coating. Although it has the advantages of strong adhesion, resistance to corrosion from general chemicals, and low price, the surface scratch resistance of this floor coating is slightly poor. Long-term use may cause more wear and scratches, which not only affects the appearance, but also the performance. Summary of the invention

[0003] The purpose of the present invention is to solve the problem of poor scratch resistance of the floor coating surface mentioned above, and to provide a solvent-free super wear-resistant polyurethane floor coating and a preparation method thereof. The prepared polyurethane floor coating is a solvent-free super wear-resistant polyurethane floor coating with excellent wear resistance, heavy object impact resistance, acid and alkali resistance, and oil resistance. The solvent-free super wear-resistant polyurethane floor coating of the present invention has a paint film with extremely high hardness (pencil hardness 6H), super wear resistance (wear resistance 8mg), excellent weather resistance (resistance to artificial weathering aging reaches 1000h), safe and reliable high anti-slip property (wet friction coefficient ≥0.77) and excellent scratch resistance.

[0004] To solve the above problems, the present invention is implemented through the following technical solutions:

[0005] The first object of the present invention is:

[0006] Provided is a solvent-free super wear-resistant polyurethane floor coating, which comprises three components A, B and C, wherein the mass ratio of component A: component B: component C is 3-5: 1-3: 2-4;

[0007] The A component comprises the following components in parts by weight:

[0008] 80-90 parts of a mixture of hexamethylene diisocyanate trimer, isophorone isocyanate trimer and uretdione isocyanate, and 6-10 parts of a siloxane coupling agent;

[0009] The B component comprises the following components in parts by weight:

[0010] 30-50 parts of bio-based polyol resin, 5-20 parts of polyisocyanate copolymer containing amino functional group, 20-30 parts of wear-resistant filler, 1-15 parts of titanium dioxide, 0.1-2 parts of rheological additive, 0.1-1.5 parts of dispersant, 0.1-1.5 parts of defoaming agent, 0.1-2 parts of leveling agent, 0.1-1 parts of catalyst, 0.1-2 parts of anti-scratch additive;

[0011] The wear-resistant filler is one or a combination of quartz powder, barium sulfate and calcium carbonate;

[0012] The titanium dioxide is subjected to surface deposition coating modification treatment, and a layer of aluminum oxide or chromium oxide is coated on the surface of the titanium dioxide to form a protective film; the mass percentage of titanium dioxide in the titanium dioxide is 94% to 95.5%, the oil absorption is 17 to 20g / 100g, and the whiteness is ≥93%;

[0013] The high refractive index of titanium dioxide (anatase type is about 2.5, rutile type is about 2.7) has strong scattering properties for visible light, providing excellent hiding power for the coating. After the surface of the rutile titanium dioxide selected by the present invention is coated with aluminum oxide or chromium oxide, the light resistance and chemical resistance of the titanium dioxide are further improved, avoiding coating failure caused by ultraviolet rays or environmental corrosion. The selected titanium dioxide has undergone special surface treatment to improve its dispersibility in the coating, ensuring the consistency and weather resistance of the coating color;

[0014] The C component comprises the following components in parts by weight:

[0015] 80-100 parts of wear-resistant aggregate, 2-5 parts of dehydrating agent;

[0016] The wear-resistant aggregate comprises aluminum oxide and glass powder, and the weight ratio of the aluminum oxide to the glass powder is 1 to 4:1.

[0017] The solvent-free super wear-resistant polyurethane floor coating of the present invention is further optimized as follows:

[0018] The weight ratio of the mixture of hexamethylene diisocyanate trimer, isophorone isocyanate trimer and uretdione isocyanate is 1-5:0.1-1:0.1-1.

[0019] The solvent-free super wear-resistant polyurethane floor coating of the present invention is further optimized as follows:

[0020] The alumina in the wear-resistant aggregate is high-strength α-type alumina; its Mohs hardness is ≥9, the appearance is white powder, the whiteness is 90-95, and the density is 3.0-3.2g / cm 3 , oil absorption 23~26g / 100g.

[0021] The solvent-free super wear-resistant polyurethane floor coating of the present invention is further optimized as follows:

[0022] The siloxane coupling agent is one or a combination of a titanate coupling agent and a silane coupling agent.

[0023] In the present invention, the siloxane coupling agent (such as silane, titanate coupling agent) improves the coating performance in the solvent-free polyurethane system through the following effects:

[0024] Enhance substrate wettability: The organic end of the siloxane structure combines with the coating organically, while the inorganic end reacts with the substrate surface (such as concrete or metal) to improve the adhesion between the coating and the substrate.

[0025] Improve coating density: Siloxane reduces pores through interfacial cross-linking during film formation, thereby improving the water resistance and chemical corrosion resistance of the coating.

[0026] Slipperiness and scratch resistance: The low surface energy characteristics of siloxane coupling agent make the coating surface smoother and improve the scratch resistance.

[0027] Some high molecular weight modified siloxane parts can also improve the stain resistance and anti-adhesion properties of the coating.

[0028] The solvent-free super wear-resistant polyurethane floor coating of the present invention is further optimized as follows:

[0029] The bio-based polyol resin is a bio-based polyester polyol resin, which is a colorless transparent liquid, has a solid content greater than 99%, a viscosity of 1000-5000cps, a hydroxyl value of 160-180mgKOH / g, and a moisture content of ≤0.05%. The selected bio-based polyol resin is used in combination with an isocyanate adduct and can be used for floor coatings, and the coating has excellent impact resistance and wear resistance. It has strong adhesion to concrete; its coating has excellent chemical resistance.

[0030] The solvent-free super wear-resistant polyurethane floor coating of the present invention is further optimized as follows:

[0031] The polyisocyanate copolymer reactant containing amino functional groups is a colorless transparent liquid with a viscosity of 900-2000 cps, an amine value of 199-203 mgKOH / g, a water content of ≤0.15%, and a density of 1.0-1.1 g / ml.

[0032] The solvent-free super wear-resistant polyurethane floor coating of the present invention is further optimized as follows:

[0033] It includes one or more of the following technical features: the rheological additive is one or a combination of several sheet silicate rheological additives; the combination of different morphological structures in its mineral components requires only extremely low shear force, is easy to disperse, and significantly shortens the processing time; does not require heating or activator activation, has effective low shear viscosity, prevents hard precipitation of pigments and fillers, reduces phase separation, and has very good pseudoplastic fluid properties; the selected sheet silicate prevents filler and pigment sedimentation by forming a thixotropic network, while enhancing the workability of the coating.

[0034] The dispersant is one or a combination of a copolymer solution containing an acidic group, an alkylamine salt of a high molecular weight copolymer, an acrylic copolymer solution containing a basic pigment affinity group, and a modified polyacrylate;

[0035] The leveling agent is one or a combination of polyether-modified polydimethylsiloxane and polyether-siloxane copolymer; polyether-modified polydimethylsiloxane or polyether-siloxane copolymer can reduce surface tension, ensure uniform leveling of the coating film, and avoid shrinkage cavities and fish-eye defects.

[0036] The defoamer is one or a combination of an organosilicon defoamer and a polymer defoamer that does not contain organosilicon. The organosilicon defoamer and the polymer defoamer that does not contain organosilicon can quickly eliminate bubbles introduced during the construction process by reducing the liquid-gas interfacial tension, thereby ensuring a smooth and flat coating.

[0037] The catalyst is one or a combination of an organic tin catalyst and an organic bismuth catalyst;

[0038] The selected catalyst is a light yellow to brown transparent liquid, which is easily soluble in common polyurethane raw materials such as polyether polyol plasticizers; it does not contain controlled heavy metals and toxic phthalates; it significantly increases the curing speed, and its catalytic activity is significantly higher than that of dibutyltin dilaurate. It has the following characteristics:

[0039] 1. High catalytic activity. It exhibits excellent catalytic activity for hexamethylene diisocyanate trimer, isophorone isocyanate trimer and uretdione isocyanate, and the non-stick time is shortened by one third (or even shorter, related to the NCO% of the formula), especially the post-curing speed is significantly improved.

[0040] 2. It dries quickly at low temperatures in winter, especially in the middle and late stages of coating curing. It overcomes the shortcoming of slow drying of organic tin driers at low temperatures in winter. When tested at low temperatures (5°C) and ambient humidity of 10-30%, it still maintains high-efficiency drying activity, and the actual drying time is shortened by half compared to that of the drier dibutyltin dilaurate, showing excellent performance.

[0041] 3. Environmentally friendly. It does not contain butyl tin and restricted heavy metals that are subject to environmental control.

[0042] The anti-scratch additive is one or a combination of an organic silicon slip agent and a wax additive.

[0043] The second object of the present invention is:

[0044] Provided is a method for preparing the aforementioned solvent-free super wear-resistant polyurethane floor coating, which comprises the following preparation steps:

[0045] Preparation of component A:

[0046] Weigh a mixture of hexamethylene diisocyanate trimer, isophorone isocyanate trimer and uretdione isocyanate, and a siloxane coupling agent according to a formula ratio, and stir them evenly to obtain component A;

[0047] Preparation of component B:

[0048] Weigh the defoaming agent, dispersant, rheological additive and polyisocyanate copolymer containing amino functional group according to the formula ratio and add them to the bio-based polyol resin. After uniform dispersion, add the wear-resistant filler and titanium dioxide and grind to a suitable fineness. Then add the leveling agent, catalyst and anti-scratch additive and stir evenly to obtain component B.

[0049] Preparation of component C:

[0050] Weigh the wear-resistant aggregate and dehydrating agent according to the formula ratio, mix them evenly, and obtain component C;

[0051] Preparation of solvent-free ultra-wear-resistant polyurethane floor coating:

[0052] The above components A, B and C are stirred and mixed in proportion to obtain a solvent-free super wear-resistant polyurethane floor coating.

[0053] The coating system of the solvent-free super wear-resistant polyurethane floor coating of the present invention is a highly cross-linked high-strength paint film generated by the reaction of a mixture of hexamethylene diisocyanate trimer, isophorone isocyanate trimer and uretdione isocyanate with a bio-based polyol resin and a polyisocyanate copolymer reactant containing an amino functional group, the interface strengthening effect of the siloxane coupling agent, the synergy of wear-resistant fillers and aggregates, and the functional optimization of additives. A solvent-free polyurethane floor coating with super high wear resistance, weather resistance and environmental protection has been successfully developed to meet the high performance requirements of modern buildings.

[0054] The solvent-free super wear-resistant polyurethane floor coating of the present invention itself has a high-strength paint film, and is matched with super scratch-resistant wear-resistant aggregate and surface anti-scratch additives, which can effectively improve the surface scratch resistance of the resin coating and extend the service life of the floor; at the same time, it has a frosted surface and a soft reflective effect, and therefore can meet the requirements of modern architecture.

[0055] The bio-based polyol resin selected in the present invention has good miscibility and dilutability in the polyurethane coating system, and also has good leveling properties, and can enhance the gloss of the paint film, and improve the strength and adhesion of the paint film; at the same time, the selected resin is non-toxic, low in odor, safe to use, and is not classified as a hazardous substance in regulations; in addition, the resin has good stability and will not oxidize and decompose during natural storage.

[0056] The bio-based polyol resin selected in the present invention has the following characteristics:

[0057] Cross-linking: The reaction of bio-based polyol resin and aliphatic isocyanate forms the matrix structure of the polyurethane coating. The coating has excellent wear resistance and impact resistance and has strong adhesion to concrete.

[0058] Environmental protection and stability: Bio-based polyol resin does not contain harmful solvents, has low odor, meets modern environmental protection needs, has strong stability, is not easy to oxidize or degrade, and the coating has excellent chemical resistance, which extends the storage life and service life of the coating.

[0059] The polyisocyanate copolymer containing amino functional groups selected in the present invention has the following characteristics:

[0060] Cross-linking: Polyisocyanate copolymers containing amino functional groups have amino groups that can react with isocyanates to form a polyurethane coating that is wear-resistant, weather-resistant, chemical-resistant, water-resistant, and has good adhesion.

[0061] In particular, the presence of bio-based polyol resin and polyisocyanate copolymer reactants containing amino functional groups synergistically increases the reaction speed, quickly builds strength and quickly adheres; at the same time, it effectively increases the cross-linking density, allowing super wear resistance to be achieved.

[0062] In the present invention, the wear-resistant filler and the wear-resistant aggregate have a synergistic effect.

[0063] Wear-resistant fillers include quartz powder, barium sulfate and other fillers:

[0064] Quartz powder has high hardness (Mohs hardness about 7);

[0065] The high density of barium sulfate particles further improves the wear and impact resistance of the coating.

[0066] Through the optimization of dispersant treatment, the wear-resistant filler is evenly distributed in the coating film, reducing sedimentation and stratification.

[0067] Wear-resistant aggregates include alumina and glass powder:

[0068] The micro-particles of aluminum oxide form a hard friction layer on the surface of the coating, improving the anti-slip performance. The particle size and ratio of the aggregate (aluminum oxide to glass powder 1 to 4:1) have been optimized to take into account the leveling and anti-wear effects of the coating.

[0069] The present invention selects a mixture of specific hexamethylene diisocyanate trimer, isophorone isocyanate trimer and uretdione isocyanate.

[0070] The hexamethylene diisocyanate trimer undergoes a cross-linking reaction with the bio-based polyol resin in component B and the polyisocyanate copolymer containing amino functional groups to generate a highly cross-linked polyurethane network structure: The cross-linking density is increased: the multiple -NCO groups in the molecular structure of the hexamethylene diisocyanate trimer react completely with the hydroxyl group and the amino group to form a highly cross-linked polyurethane network, which gives the coating film a high hardness and wear resistance. At the same time, the hexamethylene diisocyanate trimer structure does not contain benzene rings, which gives the coating film excellent yellowing resistance and weather resistance, and is particularly suitable for outdoor use. Due to the saturated bonds in its molecules, the hexamethylene diisocyanate trimer has excellent light stability and avoids photodegradation caused by ultraviolet rays.

[0071] Hexamethylene diisocyanate trimer further increases the crosslinking density of the cured coating and improves the wear resistance through the electron-withdrawing effect of the isocyanurate ring.

[0072] Urethaldione isocyanate is a chemical structure containing urea and ketone groups. It has good reactivity and can undergo cross-linking reactions with bio-based polyol resins and polyisocyanate copolymers containing amino functional groups to form a network structure. Urethaldione isocyanate itself has strong structural stability and good chemical resistance, which makes the prepared paint film have high hardness, good wear resistance, good impact resistance, and strong resistance to acids, alkalis, solvents and other corrosive substances.

[0073] Isophorone isocyanate trimer can undergo cross-linking reaction with bio-based polyol resin and polyisocyanate copolymer containing amino functional groups to generate a network structure, which provides high hardness and wear resistance as well as good UV resistance for the paint film. It can effectively prevent the floor coating from yellowing or fading under sunlight, and can enhance the coating's resistance to acids, alkalis, solvents and other chemicals.

[0074] In summary, the solvent-free super wear-resistant polyurethane floor coating and the preparation method thereof of the present invention have the following beneficial effects:

[0075] 1. Bio-based polyol resins and polyisocyanate copolymers containing amino functional groups are selected, which have good compatibility, safety and environmental protection, and the paint film has good wear resistance, impact resistance and chemical resistance.

[0076] 2. By selecting a mixture of specific hexamethylene diisocyanate trimer, isophorone isocyanate trimer and uretdione isocyanate, the paint film has excellent weather resistance and is not easy to yellow; it has super wear resistance and high surface hardness, and good resistance to acids, alkalis, solvents and other chemicals.

[0077] 3. Preferably, high-strength α-alumina with a Mohs hardness of up to 9 is introduced to improve the basic wear resistance of the paint film.

[0078] 4. Preferably, by introducing environmentally friendly and efficient organic tin catalysts and environmentally friendly organic bismuth catalysts, the catalytic activity is significantly improved compared to dibutyltin dilaurate. The non-stick time is shortened by one third (or even shorter, related to the NCO% of the formula); making early strength and fast drying possible. The surface drying is fast at low temperatures in winter, and the high-efficiency drying activity is maintained at low temperatures (5°C) and the environment, which is half the actual drying time of the drying agent dibutyltin dilaurate, and is environmentally friendly. It does not contain butyltin and restricted heavy metals that are regulated by environmental protection.

[0079] 5. By adding anti-scratch additives (such as silicone slip agents, wax additives, etc.), the scratch resistance of the paint film surface can be further improved.

[0080] 6. The entire system is solvent-free, with low VOC content, in line with modern environmental protection regulations; it does not contain free diisocyanates (such as TDI or HDI monomers), and the construction process is safe and reliable. DETAILED DESCRIPTION

[0081] In order to make the purpose, technical solutions and advantages of the present invention clearer, the present invention is described in detail below in conjunction with specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not limited to the present invention. All simple improvements to the preparation method of the present invention under the premise of the present invention's conception belong to the protection scope of the present invention.

[0082] The following are the raw materials used in the technical scheme and embodiments of the present invention, as shown in Table 1.

[0083] Table 1

[0084]

[0085] Example 1

[0086] A method for preparing a solvent-free super wear-resistant polyurethane floor coating comprises the following preparation steps:

[0087] Preparation of component A:

[0088] Weigh 80 parts of a mixture of hexamethylene diisocyanate trimer, isophorone isocyanate trimer and uretdione isocyanate and 6 parts of a siloxane coupling agent according to the formula ratio, stir them evenly, and obtain component A;

[0089] The weight ratio of the mixture of hexamethylene diisocyanate trimer, isophorone isocyanate trimer and uretdione isocyanate is 4:0.5:0.5;

[0090] Preparation of component B:

[0091] According to the formula ratio, 0.6 parts of defoaming agent, 0.5 parts of dispersant, 0.5 parts of rheological additive and 10 parts of polyisocyanate copolymer containing amino functional group are weighed and added to 30 parts of bio-based polyol resin. After uniform dispersion, 30 parts of wear-resistant filler and 10 parts of titanium dioxide are added and ground to a suitable fineness. Then, 0.5 parts of leveling agent, 1 part of catalyst and 1 part of anti-scratch additive are added and stirred evenly to obtain component B.

[0092] Preparation of component C:

[0093] Weigh 80 parts of wear-resistant aggregate and 4 parts of dehydrating agent according to the formula ratio, mix them evenly, and obtain component C;

[0094] Preparation of solvent-free ultra-wear-resistant polyurethane floor coating:

[0095] The above components A, B, and C are stirred and mixed in proportion to obtain a solvent-free super wear-resistant polyurethane floor coating, and the mass ratio of component A: component B: component C is 5:2.4:3.

[0096] Example 2

[0097] A method for preparing a solvent-free super wear-resistant polyurethane floor coating comprises the following preparation steps:

[0098] Preparation of component A:

[0099] Weigh 90 parts of a mixture of hexamethylene diisocyanate trimer, isophorone isocyanate trimer and uretdione isocyanate and 10 parts of a siloxane coupling agent according to the formula ratio, stir evenly, and obtain component A;

[0100] The weight ratio of the mixture of hexamethylene diisocyanate trimer, isophorone isocyanate trimer and uretdione isocyanate is 4:1:0.5;

[0101] Preparation of component B:

[0102] According to the formula ratio, 0.6 parts of defoaming agent, 0.5 parts of dispersant, 0.5 parts of rheological additive and 15 parts of polyisocyanate copolymer containing amino functional group are weighed and added to 30 parts of bio-based polyol resin. After uniform dispersion, 30 parts of wear-resistant filler and 10 parts of titanium dioxide are added and ground to a suitable fineness. Then, 0.5 parts of leveling agent, 1.5 parts of catalyst and 1 part of anti-scratch additive are added and stirred evenly to obtain component B.

[0103] Preparation of component C:

[0104] Weigh 90 parts of wear-resistant aggregate and 5 parts of dehydrating agent according to the formula ratio, mix them evenly, and obtain component C;

[0105] Preparation of solvent-free ultra-wear-resistant polyurethane floor coating:

[0106] The above components A, B, and C are stirred and mixed in proportion to obtain a solvent-free super wear-resistant polyurethane floor coating, and the mass ratio of component A: component B: component C is 5:2.4:3.

[0107] Comparative Example 1 and Comparative Example 2 are commercially available solvent-free super wear-resistant polyurethane floor coatings.

[0108] The performance of the solvent-free super wear-resistant polyurethane floor coatings prepared in Examples 1 and 2 was tested in accordance with the national standard GB / T22374-2018, and the test results are shown in Table 2.

[0109] Table 2 Performance test results of the coatings of the embodiments and comparative examples

[0110]

[0111]

[0112] It can be seen from Table 2 that the solvent-free super wear-resistant polyurethane floor coating prepared by the present invention has excellent properties such as wear resistance, heavy object impact resistance, acid and alkali resistance, oil resistance, and artificial aging resistance; while Comparative Examples 1 and 2 have corresponding defects in artificial aging resistance, VOC, wear resistance, pencil hardness, TVOC, etc.

[0113] To sum up, the above are only preferred embodiments of the present invention and are not intended to limit the present invention in any form. Any equivalent changes, modifications and evolutions made by technicians familiar with the profession without departing from the scope of the technical solution of the present invention using the disclosed technical content are regarded as equivalent embodiments of the present invention. At the same time, any equivalent changes, modifications and evolutions made to the above embodiments based on the essential technology of the present invention are still within the protection scope of the technical solution of the present invention.

[0114] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0115] The experimental methods without specific conditions in the present invention are usually carried out under conventional conditions or conditions recommended by the manufacturer.

[0116] Unless otherwise stated, the various optimization technical solutions in the present invention can be combined with each other.

[0117] Unless otherwise indicated, percentages and parts are by weight.

[0118] Experimental methods without specific conditions specified in the instructions and examples are usually carried out under conventional conditions or conditions recommended by the manufacturers.

[0119] Unless otherwise specified, various raw materials, reagents and components used in the present invention are corresponding raw materials commonly used in the art.

[0120] Unless otherwise defined, all professional and scientific terms used herein have the same meaning as those familiar to those skilled in the art. In addition, any method and material similar or equivalent to the described content can be applied to the method of the present invention.

Claims

1. A solvent-free super wear-resistant polyurethane floor coating, characterized in that: It includes three components A, B and C, and the mass ratio of component A: component B: component C is 3-5: 1-3: 2-4; The A component comprises the following components in parts by weight: 80-90 parts of a mixture of hexamethylene diisocyanate trimer, isophorone isocyanate trimer and uretdione isocyanate, and 6-10 parts of a siloxane coupling agent; The B component comprises the following components in parts by weight: 30-50 parts of bio-based polyol resin, 5-20 parts of polyisocyanate copolymer containing amino functional group, 20-30 parts of wear-resistant filler, 1-15 parts of titanium dioxide, 0.1-2 parts of rheological additive, 0.1-1.5 parts of dispersant, 0.1-1.5 parts of defoaming agent, 0.1-2 parts of leveling agent, 0.1-1 parts of catalyst, 0.1-2 parts of anti-scratch additive; The wear-resistant filler is one or a combination of quartz powder, barium sulfate and calcium carbonate; The titanium dioxide is subjected to surface deposition coating modification treatment, and a layer of aluminum oxide or chromium oxide is coated on the surface of the titanium dioxide to form a protective film; the mass percentage of titanium dioxide in the titanium dioxide is 94% to 95.5%, the oil absorption is 17 to 20g / 100g, and the whiteness is ≥93%; The C component comprises the following components in parts by weight: 80-100 parts of wear-resistant aggregate, 2-5 parts of dehydrating agent; The wear-resistant aggregate comprises aluminum oxide and glass powder, and the weight ratio of the aluminum oxide to the glass powder is 1 to 4:

1.

2. The solvent-free super wear-resistant polyurethane floor coating according to claim 1, characterized in that: The weight ratio of the mixture of hexamethylene diisocyanate trimer, isophorone isocyanate trimer and uretdione isocyanate is 1-5:0.1-1:0.1-1.

3. The solvent-free super wear-resistant polyurethane floor coating according to claim 1, characterized in that: The alumina in the wear-resistant aggregate is high-strength α-type alumina; its Mohs hardness is ≥9, the appearance is white powder, the whiteness is 90-95, and the density is 3.0-3.2g / cm 3 , oil absorption 23~26g / 100g.

4. The solvent-free super wear-resistant polyurethane floor coating according to claim 1, characterized in that: The siloxane coupling agent is one or a combination of a titanate coupling agent and a silane coupling agent.

5. The solvent-free super wear-resistant polyurethane floor coating according to claim 1, characterized in that: The bio-based polyol resin is a bio-based polyester polyol resin, which is a colorless transparent liquid, has a solid content greater than 99%, a viscosity of 1000-5000 cps, a hydroxyl value of 160-180 mgKOH / g, and a water content of ≤0.05%.

6. The solvent-free super wear-resistant polyurethane floor coating according to claim 1, characterized in that: The polyisocyanate copolymer reactant containing amino functional groups is a colorless transparent liquid with a viscosity of 900-2000 cps, an amine value of 199-203 mgKOH / g, a water content of ≤0.15%, and a density of 1.0-1.1 g / ml.

7. The solvent-free super wear-resistant polyurethane floor coating according to claim 1, characterized in that: It includes one or more of the following technical features: The rheological additive is one or a combination of sheet silicate rheological additives; The dispersant is one or a combination of a copolymer solution containing an acidic group, an alkylamine salt of a high molecular weight copolymer, an acrylic copolymer solution containing a basic pigment affinity group, and a modified polyacrylate; The leveling agent is one or a combination of polyether modified polydimethylsiloxane and polyether siloxane copolymer; The defoamer is one or a combination of an organosilicon defoamer and a polymer defoamer that does not contain organosilicon; The catalyst is one or a combination of an organic tin catalyst and an organic bismuth catalyst; The anti-scratch additive is one or a combination of an organic silicon slip agent and a wax additive.

8. A method for preparing the solvent-free super wear-resistant polyurethane floor coating according to claim 1, characterized in that: It comprises the following preparation steps: Preparation of component A: Weigh a mixture of hexamethylene diisocyanate trimer, isophorone isocyanate trimer and uretdione isocyanate, and a siloxane coupling agent according to a formula ratio, and stir them evenly to obtain component A; Preparation of component B: Weigh the defoaming agent, dispersant, rheological additive and polyisocyanate copolymer containing amino functional group according to the formula ratio and add them to the bio-based polyol resin. After uniform dispersion, add the wear-resistant filler and titanium dioxide and grind to a suitable fineness. Then add the leveling agent, catalyst and anti-scratch additive and stir evenly to obtain component B. Preparation of component C: Weigh the wear-resistant aggregate and dehydrating agent according to the formula ratio, mix them evenly, and obtain component C; Preparation of solvent-free ultra-wear-resistant polyurethane floor coating: The above components A, B and C are stirred and mixed in proportion to obtain a solvent-free super wear-resistant polyurethane floor coating.

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