Solvent-free sprayable putty

Abstract

The invention relates to the technical field of coatings, and discloses solvent-free sprayable putty which comprises a component A and a component B. The mass ratio of the component A to the component B is 2: 1, and the component A comprises, by mass, 45-50% of polyol resin, 5-8% of a dispersing agent, 0.5% of a wetting agent, 0.5% of a defoaming agent, 8-10% of titanium dioxide, 14-17% of first functional filler, 8-10% of second functional filler and 1% of an anti-settling agent. And the component B comprises the following components in percentage by mass: 100% of a polyurethane curing agent, 0.8% of a water removal agent and 5-10% of feldspar powder. Through cross-linking and curing of the polyurethane curing agent and the polyol resin, the use of a solvent can be avoided, the generation of volatile substances can be reduced, meanwhile, a high-density and wear-resistant polyurethane coating can be formed, and the polyurethane coating has high adhesive force, wear resistance, impact resistance and weather resistance stability in cooperation with the use of the functional filler.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of paint, in particular to a solvent-free sprayable putty. BACKGROUND

[0002] Paint is a material that can be coated on the surface of an object and form a continuous film of firm adhesion, usually composed of film-forming substances, pigments, solvents and additives. It can be applied by brushing, spraying, rolling and other methods, and after drying, it forms a coating on the surface of the object with protection, decoration or special functions (such as corrosion resistance, insulation, mildew resistance, etc.), widely used in construction, automobiles, furniture, machinery and many other fields, beautifying the appearance and prolonging the service life of the object, and putty is a common paint.

[0003] The existing putty realizes the construction fluidity by dissolving the resin with a solvent, but the physical dry film layer formed after the solvent volatilizes has low density and accelerates water penetration, resulting in low adhesion and poor wear resistance, which cannot meet the needs of high wear resistance scenes and is prone to cracking when the substrate shrinks. SUMMARY

[0004] In view of the deficiencies of the prior art, the present application provides a solvent-free sprayable putty, which solves the problem that the existing putty cannot meet the needs of high wear resistance scenes and is prone to cracking when the substrate shrinks due to the use of a solvent to dissolve the resin to achieve construction fluidity.

[0005] To achieve the above purpose, the present application realizes the following technical scheme: a solvent-free sprayable putty, comprising component A and component B: the mass ratio of component A to component B is 2:1, wherein component A contains the following components by mass percentage: polyol resin 45-50%, dispersing agent 5-8%, wetting agent 0.5%, defoaming agent 0.5%, titanium white 8-10%, functional filler one 14-17%, functional filler two 8-10%, anti-settling agent 1%, water removal agent 0.8% and feldspar 5-10%, and component B contains the following components by mass percentage: polyurethane curing agent 100%.

[0006] Through the above technical solution, the solvent-free sprayable putty is composed of two components A and B in a mass ratio of 2:1, wherein component A contains 45%-50% polyether polyol as the main film-forming substance, which reacts with the isocyanate group of the polyurethane curing agent of component B to form a three-dimensional network polyurethane structure; the dispersant maintains the stability of the system through the electrostatic steric effect, and the wetting agent cooperates with the defoaming agent to reduce the surface tension to 28mN / m, achieving a spray atomization particle size median of 60μm; when the titanium dioxide dosage exceeds 10%, the paint film Porosity > 8%; calcium carbonate or talc (oil absorption value 25g / 100g) adjusts the rheology to a Stormer viscosity of 95-105KU, muscovite powder forms a water vapor barrier layer, and quartz powder (Mohs hardness 7.0) improves wear resistance; the organic bentonite anti-settling agent constructs a thixotropic network through 1nm flakes (viscosity recovery coefficient > 0.95), and the water scavenger can absorb 300ppm of moisture, thereby achieving the effect of making the putty have higher adhesion, wear resistance, impact resistance and weather stability.

[0007] Preferably, the first functional filler is at least one of calcium carbonate and talc powder, and the second functional filler is at least one of mica powder and quartz powder.

[0008] Preferably, the polyol resin is a polyether polyol with a hydroxyl value ranging from 100 to 200 mgKOH / g.

[0009] Preferably, the polyurethane curing agent contains an isocyanate group, and is selected from at least one of hexamethylene diisocyanate trimer, phorone diisocyanate trimer and diphenylmethane diisocyanate derivatives.

[0010] Preferably, the dispersant is a high molecular weight polycarboxylate dispersant, and the wetting agent is a silicone modified polyether wetting agent.

[0011] Preferably, the anti-settling agent is organic bentonite, and the water scavenger is triethyl orthoformate.

[0012] Preferably, the feldspar powder has a particle size distribution of 800-1250 meshes and a Mohs hardness of ≥6.

[0013] Preferably, a method for preparing a solvent-free sprayable putty comprises the following steps: S1. Preparation of component A: First, stir the polyol resin, dispersant, wetting agent and defoamer at a low speed of 200-400 rpm for 5-10 minutes; then add titanium dioxide, functional filler 1, functional filler 2, anti-settling agent, water remover and feldspar powder in sequence, and stir at a high speed of 800-1200 rpm for 15-25 minutes until the mixture is uniform and free of particles; S2. Sealed storage tank: After the preparation of the A component, it is sealed and stored with the B component according to the ratio. The storage temperature is controlled at 5-30 ° C. S3. Mixing before construction: Before construction, add component B to component A at a uniform speed, stir at a speed of 500-800 rpm for 3-5 minutes to mix evenly to obtain putty. The putty can be cured at room temperature to form a polyurethane film layer.

[0014] Preferably, the dispersant in S1 is added in batches: 50% of the dispersant is premixed with the polyol resin and the wetting agent at 200-400 rpm, and the remaining dispersant is added when the stirring time is more than half at a low speed.

[0015] Preferably, the B component in S2 is stored in a sealed aluminum can filled with nitrogen with an oxygen content of ≤0.5%, and the pressure in the can is maintained at 0.05-0.1 MPa. The inner wall of the A component storage container is covered with a polytetrafluoroethylene anti-adsorption coating with a coating thickness of 50-100 μm.

[0016] The present invention provides a solvent-free sprayable putty having the following beneficial effects: 1. The present invention can avoid the use of solvents and reduce the generation of volatile substances through cross-linking and curing of polyurethane curing agent and polyol resin. At the same time, it can form a highly dense and wear-resistant polyurethane coating, and cooperate with the use of functional fillers to achieve the effect of making the putty have higher adhesion, wear resistance, impact resistance and weather resistance stability.

[0017] 2. The present invention ensures uniform dispersion of solid particles through dispersants and wetting agents, improves substrate wettability, and the provision of anti-settling agents and feldspar powder enhances the rheological properties of putty, thereby facilitating spraying construction.

[0018] 3. The present invention replaces 30% of titanium dioxide with feldspar powder (1250 mesh accounting for ≥70%), and uses its silica content >65% to form hydrogen bonds with polyurethane (bond energy 30kJ / mol). Under the premise of maintaining the Stormer viscosity at 100KU, the raw material cost can be reduced by 18% and the grinding weight loss rate can be ≤6mg / s, thus taking into account both performance and economy.

[0019] 4. The present invention forms a water vapor barrier layer by arranging two functional fillers in parallel, and cooperates with feldspar powder (Mohs hardness ≥ 6) to increase the fracture energy to 8.5kJ / m 2 Combined with the control of polyurethane cross-linking density, it can achieve 10 times of -30℃ / 80℃ hot and cold cycles without cracking, greatly extending the service life of the coating. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 The present invention is a process flow chart of a solvent-free sprayable putty. DETAILED DESCRIPTION

[0021] The following will clearly and completely describe the technical solution of the present invention in conjunction with the accompanying drawings. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0022] An embodiment of the present invention provides a solvent-free sprayable putty, including component A and component B: the mass ratio of component A to component B is 2:1, wherein component A contains the following ingredients by mass percentage: 45-50% polyol resin, 5-8% dispersant, 0.5% wetting agent, 0.5% defoaming agent, 8-10% titanium dioxide, 14-17% functional filler 1, 8-10% functional filler 2, 1% anti-settling agent, 0.8% dewatering agent and 5-10% feldspar powder, and component B contains the following ingredients by mass percentage: 100% polyurethane curing agent.

[0023] Specifically, the solvent-free sprayable putty is composed of component A and component B in a mass ratio of 2:1, wherein component A contains 45% to 50% by mass of polyether polyol as the main film-forming substance, which undergoes a polyaddition reaction with the isocyanate group of the polyurethane curing agent of component B to form a three-dimensional network polyurethane structure; the dispersant maintains the dispersion stability of the system through the electrostatic steric effect; the wetting agent cooperates with the defoaming agent to reduce the surface tension of the system to 28mN / m, achieving a median spray atomization particle size of 60μm; titanium dioxide provides hiding power, and its upper limit of mass percentage is based on the critical pigment The volume concentration experiment is set up so that when the porosity of the paint film exceeds 10%, the mercury intrusion method measures the porosity to be greater than 8%; calcium carbonate or talc powder is used as the first functional filler, with an oil absorption value of 25g / 100g, and the rheological properties are adjusted to a Stormer viscosity of 95-105KU; muscovite powder or quartz powder is used as the second functional filler, with a mica powder diameter-to-thickness ratio greater than 50 to form a water vapor barrier layer, and quartz powder with a Mohs hardness of 7.0 to improve wear resistance; the anti-settling agent uses organic bentonite, which constructs a thixotropic network through a 1nm lamellar structure, and the viscosity recovery coefficient is greater than 0.95; the water remover can absorb 300ppm of moisture.

[0024] The first functional filler is at least one of calcium carbonate and talc powder, and the second functional filler is at least one of mica powder and quartz powder.

[0025] Specifically, the functional filler 1 is selected from at least one of heavy calcium carbonate or talc, wherein the particle size of the heavy calcium carbonate is controlled in the range of 1250 mesh and the oil absorption value is 20-30g / 100g. The volume solid content of the paint film is increased by physical filling, and its calcite crystal structure forms a mechanical anchoring effect with the urethane bond generated during the curing process of the polyurethane; the talc uses a layered silicate with a 1250 mesh and an aspect ratio greater than 10, and its siloxane surface produces hydrogen bond adsorption with the ether bond of the polyol resin, reducing the shear viscosity of the system to a Stormer viscosity of 95-105KU. The total addition amount of the functional filler 1 is 14%-17%. The rheometer test confirms that the thixotropic index at this ratio is 4.2, which can ensure that the 500μm wet film on the vertical surface has no sag. The functional filler 2 is selected from at least one of 300 mesh muscovite powder or 400 mesh quartz powder. The mica powder has a lamellar structure with an aspect ratio of more than 50 and is arranged in parallel in the paint film, and the water vapor transmission rate is less than 5g / m 2 · day; quartz powder with a Mohs hardness of 7.0 angular particles improves crack resistance by increasing the crack propagation path, and the fracture energy can be increased to 8.5kJ / m in a three-point bending test 2 .

[0026] The polyol resin is a polyether polyol with a hydroxyl value ranging from 100 to 200 mgKOH / g.

[0027] Specifically, the polyol resin uses a polyether polyol with a hydroxyl value range of 100-200 mgKOH / g. This hydroxyl value range has been verified by gel permeation chromatography. When the hydroxyl value is lower than 100 mgKOH / g, the polyurethane crosslinking density is insufficient, resulting in a 40% decrease in the wear resistance of the paint film; when the hydroxyl value is higher than 200 mgKOH / g, the system viscosity increases sharply to >5000 mPa·s, affecting the spray atomization effect. The molecular weight of the polyether polyol is controlled at 3000-5000 g / mol, and its terminal primary hydroxyl content is >70% to enhance the reactivity with isocyanate. This structure reduces the activation energy of the -NCO / -OH reaction to 45 kJ / mol, which increases the reaction rate compared to the secondary hydroxyl system.

[0028] The polyurethane curing agent contains an isocyanate group and is selected from at least one of hexamethylene diisocyanate trimer, phorone diisocyanate trimer and diphenylmethane diisocyanate derivatives.

[0029] Specifically, the polyurethane curing agent contains an isocyanate group, which is selected from at least one of hexamethylene diisocyanate trimer, isophorone diisocyanate trimer and diphenylmethane diisocyanate derivatives, wherein the isocyanate group content of hexamethylene diisocyanate trimer is 21.5±0.5%, and its aliphatic structure makes the paint film highly weatherable, with a gloss retention rate of >85% after 1000 hours of QUV aging test; the cyclic structure of isophorone diisocyanate trimer increases the glass transition temperature to 75°C, making it suitable for high temperature environments; diphenylmethane diisocyanate derivatives contain rigid benzene rings and have a tensile strength of 12.3 MPa. When these three curing agents react with the hydroxyl groups of the polyol resin, the reaction activation energies are 45 kJ / mol, 50 kJ / mol and 55 kJ / mol, respectively, and the gel time is controlled in the range of 20-30 minutes.

[0030] The dispersant is a high molecular weight polycarboxylate dispersant, and the wetting agent is a silicone modified polyether wetting agent.

[0031] Specifically, the dispersant uses a polycarboxylate dispersant, which forms an ionic bond anchoring effect between the carboxylate anions and the calcium ions on the filler surface. At the same time, the long polyether chain produces a steric hindrance effect, so that the dispersion fineness of titanium dioxide and functional fillers is ≤15μm; the wetting agent uses a silicone-modified polyether compound, whose polydimethylsiloxane chain segment reduces the surface tension to 28mN / m, and the ethylene oxide / propylene oxide block structure is directionally adsorbed on the defects of the substrate, so that the contact angle of the concrete substrate is reduced to below 15°.

[0032] The anti-settling agent is organic bentonite and the water removing agent is triethyl orthoformate.

[0033] Specifically, the anti-settling agent uses organic bentonite with a layer thickness of 1 nm. Under the action of shear force, it dissociates in the polyol resin to form a three-dimensional hydrogen bond network. This structure increases the viscosity of the system to 12,000 mPa·s at a low shear rate, and the thixotropic index reaches 4.2. When the organic bentonite is added at a rate of 1%, the rotational rheometer test confirms that the viscosity recovery time is less than 10 seconds, and the sedimentation rate after storage for 90 days is less than 0.1%; the dehydrating agent uses triethyl orthoformate, in which the ethoxy group undergoes an ester exchange reaction with the trace moisture in the system to generate ethanol and ethyl formate, and the reaction rate constant is 0.15 h-1 (25°C). The dehydrating agent can reduce the moisture content of the system from 800 ppm to below 80 ppm, preventing moisture from reacting with isocyanate groups to produce carbon dioxide bubbles.

[0034] The particle size distribution of feldspar powder is 800-1250 mesh, and the Mohs hardness is ≥6.

[0035] Specifically, the feldspar powder is made of potassium feldspar or sodium feldspar minerals, and its particle size distribution is controlled in the range of 800-1250 mesh, of which 800 mesh particles account for ≤15% and 1250 mesh particles ≥70%. The Mohs hardness ≥6 enables it to form a rigid skeleton during the curing process of the paint film. The Taber wear test shows that the wear loss is ≤22mg / 1000 revolutions. The flake and granular particles in the feldspar powder are compounded (aspect ratio of 1.5-3.0) to form secondary support points in the thixotropic network of the organic bentonite. The rotational viscometer test shows that the thixotropic index is increased to 4.5. At the same time, the surface silanol of the feldspar powder with a silica content of >65% forms hydrogen bonds with the polyurethane urethane group, with a bond energy of about 30kJ / mol. The three-point bending test increases the fracture energy from 7.2kJ / m 2 Increased to 8.5kJ / m 2 , and feldspar powder can replace 20%-30% of titanium dioxide, while the Stormer viscosity remains stable at 100±5KU, and the raw material cost is reduced by 18%±2%.

[0036] See attached Figure 1 , a method for preparing a solvent-free sprayable putty, comprising the following steps: S1. Preparation of component A: First, stir the polyol resin, dispersant, wetting agent and defoamer at a low speed of 200-400 rpm for 5-10 minutes; then add titanium dioxide, functional filler 1, functional filler 2, anti-settling agent, water remover and feldspar powder in sequence, and stir at a high speed of 800-1200 rpm for 15-25 minutes until the mixture is uniform and free of particles; S2. Sealed storage tank: After component A is prepared, it is sealed and stored separately with component B according to the ratio, and the storage temperature is controlled at 5-30℃; S3. Mixing before construction: Before construction, add component B to component A at a uniform speed, stir at a speed of 500-800rpm for 3-5 minutes to obtain putty. The putty can be cured at room temperature to form a polyurethane film layer.

[0037] Specifically, in the preparation of component A in stage S1, first, polyether polyol, polycarboxylate dispersant, silicone polyether wetting agent and defoamer are placed in a stirring kettle and stirred at a low speed of 200-400 rpm for 5-10 minutes to ensure that the additive molecules are adsorbed on the resin chain to form a pre-wetting layer with a thickness of about 5nm; then titanium dioxide, functional filler 1, functional filler 2, organic bentonite anti-settling agent, triethyl orthoformate dewatering agent, and feldspar powder are added in sequence, and the speed is increased to 800-1200 rpm and stirred at high speed for 15-25 minutes. The blade tip linear speed reaches 15m / s to break the filler aggregates. In stage S2, it is sealed and stored. When storing in S3, component A is stored in a polytetrafluoroethylene-lined container, and component B, a hexamethylene diisocyanate trimer curing agent, is sealed with nitrogen containing less than 0.5% oxygen. The ambient temperature is 5-30°C to inhibit the side reaction of the isocyanate group with water vapor. The viscosity change rate after storage for 30 days is less than 5%. In S3, component B is added to component A at a flow rate of 20 g / s, and stirred at a speed of 500-800 rpm for 3-5 minutes. The laminar vortex with a Reynolds number of 1400 makes the reaction degree of the isocyanate group and the hydroxyl group reach 18%, and the mixed viscosity is stabilized at 4500 mPa·s. The wet film thickness of the spraying is 100 μm within 30 minutes after mixing.

[0038] See attached Figure 1 The dispersant in S1 is added in batches: 50% of the dispersant is premixed with the polyol resin and the wetting agent at 200-400 rpm, and the remaining dispersant is added when the stirring time is more than half at a low speed.

[0039] Specifically, during the preparation of component A in stage S1, first, 50% of the total amount of high molecular weight polycarboxylate dispersant, polyether polyol, and silicone polyether wetting agent are placed in a stirring kettle and premixed at a speed of 200-400 rpm to ensure that the hydrophobic chain segment of the dispersant is fully anchored to the resin molecules to form a pre-adsorption layer with a thickness of about 8 nm; when the low-speed stirring is carried out to half of the total time, the remaining 50% of the dispersant is added at a uniform speed, and the stirring is continued at the maintained speed. The carboxylate groups of the dispersant and the ether bonds of the polyol form hydrogen bonds with a bond energy of about 25 kJ / mol in the premixing stage to reduce the interfacial energy to 40 mJ / m 2 The mid-term addition allows the newly added dispersant molecules to penetrate the gaps in the pre-adsorption layer, and the thickness of the steric hindrance layer increases from 8nm to 12nm, thereby achieving a titanium dioxide dispersion fineness of ≤12μm, which is 40% higher than that of one-time addition. After high-speed dispersion, the Hegmann fineness reaches 10μm, the viscosity change rate after 30 days of storage is <3%, the sedimentation volume is 0.2mL, and the paint film surface roughness Ra=0.8μm.

[0040] See attached Figure 1 When storing component B in S2, a sealed aluminum can filled with nitrogen with an oxygen content of ≤0.5% is used, and the pressure inside the can is maintained at 0.05-0.1MPa. The inner wall of the storage container of component A is covered with a polytetrafluoroethylene anti-adsorption coating with a coating thickness of 50-100μm.

[0041] Specifically, the B component hexamethylene diisocyanate trimer curing agent is stored in a sealed aluminum can filled with nitrogen with an oxygen content of ≤0.5%. The can body is made of AA3003 aluminum alloy with a thickness of 1.0±0.1mm. The pressure inside the can is maintained at a constant 0.08±0.02MPa through a pressure reducing valve. This positive pressure environment blocks the infiltration of external moisture and makes the moisture permeability ≤5mg / m 2 The isocyanate group hydrolysis side reaction rate is controlled to ≤0.1% / month in combination with the GB / T8979 Class 1 nitrogen purity standard. The inner wall of the A component storage container is covered with a 50-100μm thick polytetrafluoroethylene coating, which can reduce the adsorption loss of the polycarboxylate dispersant on the tank wall to <0.3mg / cm 2 .

[0042] Example 1: Composition (mass percentage): Component A: 45% polyether polyol, 8% polycarboxylate dispersant, 0.5% silicone polyether wetting agent, 0.5% defoamer, 8% titanium dioxide, 17% calcium carbonate, 8% mica powder, 1% organic bentonite, 0.8% triethyl orthoformate and 10% feldspar powder. The remaining ingredients are supplemented with deionized water. Component B: hexamethylene diisocyanate trimer 100%.

[0043] Ratio: Component A: Component B = 2:1.

[0044] Preparation process: S1. Preparation of component A: First, stir the polyol resin, dispersant, wetting agent and defoamer at a low speed of 200 rpm for 5 minutes; then add titanium dioxide, functional filler 1, functional filler 2, anti-settling agent, water remover and feldspar powder in sequence, and stir at a high speed of 800 rpm for 15 minutes until the mixture is uniform and free of particles; S2. Sealed storage tank: After the preparation of the A component, it is sealed and stored with the B component according to the ratio, and the storage temperature is controlled at 5°C; S3. Mixing before construction: Before construction, add component B to component A at a uniform speed, stir at 500 rpm for 3 minutes to mix evenly to obtain putty. The putty can be cured at room temperature to form a polyurethane film layer.

[0045] Performance testing: Adhesion: concrete substrate cross-hatch method (GB / T9286); Wear resistance: Taber wear test (ISO7784-2); VOC: thermal desorption-GC / MS (GB / T23986); Weather resistance: QUV-B1000h (ISO11507).

[0046] Application: concrete exterior wall spraying, wet film 100μm, surface dry 25min, no sagging Control experimental group 1: Element: Component A: add 15% xylene solvent and reduce the polyol content to 35%. Other contents are the same as in Example 1.

[0047] Process: Dispersant was added at one time and stored without nitrogen. Other steps were the same as in Example 1.

[0048] Performance comparison table 1: Test items Control group 1 Example 1 in conclusion VOC content 410g / L 1.5g / L Reduced VOC content Adhesion (concrete) Level 2 Level 0 Improved adhesion QUV gloss retention rate 1000h 62％ 88％ Improved weather resistance Example 2: Element: Component A: polyol resin 46%, dispersant 7%, wetting agent 0.5%, defoaming agent 0.5%, titanium dioxide 9%, functional filler 1 15%, functional filler 2 9%, anti-settling agent 1%, dewatering agent 0.8% and feldspar powder 7%. The remaining ingredients are supplemented with deionized water.

[0049] Component B: Isophorone diisocyanate trimer 100%. Ratio: Component A: Component B = 2:1.

[0050] Process: S1. Preparation of component A: First, stir the polyol resin, dispersant, wetting agent and defoamer at a low speed of 300 rpm for 8 minutes; then add titanium dioxide, functional filler 1, functional filler 2, anti-settling agent, water remover and feldspar powder in sequence, and stir at a high speed of 1000 rpm for 20 minutes until the mixture is uniform and free of particles; S2. Sealed storage tank: After the preparation of the A component, it is sealed and stored with the B component according to the ratio, and the storage temperature is controlled at 18 ° C. S3. Mixing before construction: Before construction, add component B to component A at a uniform speed, stir at 700 rpm for 4 minutes to mix evenly to obtain putty. The putty can be cured at room temperature to form a polyurethane film layer.

[0051] Performance testing: Temperature resistance: baking at 80℃ for 24h (GB / T1735); Hardness: Pendulum hardness (GB / T1730); Crack resistance: -30℃ / 80℃ cycle 10 times (GB / T35153).

[0052] Control experimental group 2: Composition: A:B=1:1, other ingredients are the same as in Example 2; Process: non-gradient dispersion, one-time addition of filler, other procedures are the same as those in Example 2.

[0053] Performance Control Table 2: Test items Control group 2 Example 2 in conclusion Bubble area at 80℃ 15％ 0％ Improved temperature resistance Hot and cold cycle cracking Crack length 3.2mm No cracks Improved crack resistance Spray sag (vertical surface) Sagging thickness 200μm No sagging Optimized construction performance Example 3: Ingredients: A component: polyol resin 50%, dispersant 8%, wetting agent 0.5%, antifoaming agent 0.5%, titanium white 10%, functional filler one 14%, functional filler two 10%, anti-settling agent 1%, water-removing agent 0.8%, and feldspar 5%, and the rest is supplemented with deionized water.

[0054] B component: diphenylmethane diisocyanate derivative 100%.

[0055] Ratio: A component: B component = 2:1.

[0056] Process: S1, A component preparation: first, low-speed stirring of polyol resin, dispersant, wetting agent, and antifoaming agent at 400 rpm for 10 minutes; then, adding titanium white, functional filler one, functional filler two, anti-settling agent, water-removing agent, and feldspar in sequence, high-speed stirring at 1200 rpm for 25 minutes until uniform and no particles; S2, sealed storage tank: after the preparation of the A component, the B component is sealed and stored according to the ratio, and the storage temperature is controlled at 30°C; S3, mixing before construction: before construction, the B component is uniformly added to the A component, and stirred at 800 rpm for 5 minutes to mix evenly to obtain putty, which can be cured at room temperature to form a polyurethane film layer.

[0057] Performance detection: Polishing: 400-mesh sandpaper polishing (GB / T1770); Hiding power: black and white grid method (GB / T1726).

[0058] Control experiment group 3: Ingredients: same as example 3; Process: dispersant is added at one time, without polytetrafluoroethylene lining, and the rest is consistent with example 3 Performance: Test items Control group 3 Example 3 in conclusion 30-day sedimentation volume 3.2mL 0.3mL Stability improvements Paint film roughness Ra 2.5μm 0.9μm Improved surface quality Dispersant adsorption loss <![CDATA[1.8mg / cm 2 ]]> 0.2mg / c Improved utilization Conclusion: Environmental protection breakthrough: solvent-free formula reduces VOC to 1.5-2 g / L; Process advantage: dispersant is added in batches to make fineness ≤12 μm; Economic benefit: feldspar replaces titanium white to reduce cost by 22% with the same performance; Durability guarantee: nitrogen storage process makes NCO decay rate ≤0.1% / month.

[0059] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. A solvent-free sprayable putty, characterized in that: The invention comprises component A and component B: the mass ratio of component A to component B is 2:1, wherein component A comprises the following ingredients by mass percentage: 45-50% of polyol resin, 5-8% of dispersant, 0.5% of wetting agent, 0.5% of defoaming agent, 8-10% of titanium dioxide, 14-17% of functional filler 1, 8-10% of functional filler 2, 1% of anti-settling agent, 0.8% of water removing agent and 5-10% of feldspar powder, and component B comprises the following ingredients by mass percentage: 100% of polyurethane curing agent.

2. A solvent-free sprayable putty according to claim 1, characterized in that, The first functional filler is at least one of calcium carbonate and talc powder, and the second functional filler is at least one of mica powder and quartz powder.

3. A solvent-free sprayable putty according to claim 1, characterized in that, The polyol resin is a polyether polyol with a hydroxyl value ranging from 100 to 200 mgKOH / g.

4. A solvent-free sprayable putty according to claim 1, characterized in that, The polyurethane curing agent contains an isocyanate group and is selected from at least one of hexamethylene diisocyanate trimer, phorone diisocyanate trimer and diphenylmethane diisocyanate derivatives.

5. A solvent-free sprayable putty according to claim 1, characterized in that, The dispersant is a high molecular weight polycarboxylate dispersant, and the wetting agent is an organosilicon modified polyether wetting agent.

6. A solvent-free sprayable putty according to claim 1, characterized in that: The anti-settling agent is organic bentonite, and the water removing agent is triethyl orthoformate.

7. The solvent-free sprayable putty according to claim 1, characterized in that: The feldspar powder has a particle size distribution of 800-1250 meshes and a Mohs hardness of ≥6.

8. A method for preparing a solvent-free sprayable putty, characterized in that: A solvent-free sprayable putty according to any one of claims 1 to 7, comprising the following steps: S1. Preparation of component A: First, stir the polyol resin, dispersant, wetting agent and defoamer at a low speed of 200-400 rpm for 5-10 minutes; then add titanium dioxide, functional filler 1, functional filler 2, anti-settling agent, water remover and feldspar powder in sequence, and stir at a high speed of 800-1200 rpm for 15-25 minutes until the mixture is uniform and free of particles; S2. Sealed storage tank: After the preparation of the A component, it is sealed and stored with the B component according to the ratio. The storage temperature is controlled at 5-30 ° C. S3. Mixing before construction: Before construction, add component B to component A at a uniform speed, stir at a speed of 500-800 rpm for 3-5 minutes to mix evenly to obtain putty. The putty can be cured at room temperature to form a polyurethane film layer.

9. The method for preparing a solvent-free sprayable putty according to claim 8, wherein: The dispersant described in S1 is added in batches: 50% of the dispersant is premixed with the polyol resin and the wetting agent at 200-400 rpm, and the remaining dispersant is added when the stirring time is more than half at a low speed.

10. The method for preparing a solvent-free sprayable putty according to claim 8, wherein: The B component in S2 is stored in a sealed aluminum can filled with nitrogen with an oxygen content of ≤0.5%, and the pressure in the can is maintained at 0.05-0.1 MPa. The inner wall of the storage container of the A component is covered with a polytetrafluoroethylene anti-adsorption coating with a coating thickness of 50-100 μm.

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