CN110229598A - Cool down coating and its preparation method and application - Google Patents

Abstract

The invention discloses a cooling coating and its preparation method and application, comprising a bottom layer, a middle layer and a surface layer, the bottom layer is a modified solvent-free sealing waterproof coating; by weight percentage, the middle layer includes 20-50% of polyurethane resin and functional Material 50-80%; by weight percentage, the surface layer includes: organic-inorganic hybrid resin 40-70%, reflective titanium dioxide 5-20%, reflective black pigment 1-5%, far-infrared radiation fine powder 3-10% and Solvent 5‑15%. Compared with the prior art, the present invention has the following advantages: (1) the normal tensile strength of the ballastless track slab concrete is enhanced by more than 50%; (2) the surface temperature of the concrete can be reduced by more than 15°C under hot sunlight; (3) it can Reduce the temperature difference between the upper and lower surfaces of the concrete by more than 10°C; (4) the near-infrared reflectivity of the cement-like color reaches more than 80%; (5) the coating has intrinsic self-cleaning performance and will not produce obvious attenuation; (6) the coating The aging resistance is extremely strong, and the outdoor service life can reach more than 30 years; (7) It adopts phase change temperature control design to intelligently control the temperature of the protected object.

Description

Cooling coating and its preparation method and application

technical field

The invention belongs to the technical field of coatings, and relates to a coating with the functions of concrete reinforcement, phase change intelligent temperature control, heat blocking, radiation reflection, self-cleaning, super weather resistance and anti-aging, specifically a cooling coating and its preparation method and application.

Background technique

The planning scope of my country's high-speed railways spans from north to south, and from east to west, and the climate conditions in the areas where the high-speed lines are located are relatively complex. It can be seen from the surface temperature map that most high-speed railways operate at high temperatures in summer, especially at high temperatures above 40°C for more than a week. Under the coupled effects of temperature stress generated by ambient high temperatures and train load impacts, it is easy to cause some ballastless track slabs to warp Deformation, cracking and other situations have become hidden dangers for the long-term safe operation of high-speed rail. At present, no protective measures have been taken on the surface of ballastless track slabs to reduce the temperature, and the existing concrete protective coatings cannot meet the protection requirements of high-speed rail ballastless track slabs in terms of life and performance. In order to solve the problems faced by the ballastless track of the high-speed railway, protective coating can be applied to the existing track to reduce the peak temperature of the concrete surface, reduce the temperature difference between the upper and lower surfaces of the concrete, and reduce the effect of the temperature difference stress of the concrete structure on the ballastless track. Thereby ensuring the stability of the ballastless track under high temperature conditions and improving its service performance.

Contents of the invention

The technical problem to be solved: In order to overcome the deficiencies of the existing technology, obtain a coating with the functions of concrete reinforcement, phase change intelligent temperature control, heat barrier, radiation reflection, self-cleaning and super weather resistance and aging resistance, so as to reduce the concrete structure The effect of temperature difference stress on the ballastless track, so as to ensure the stability of the ballastless track under high temperature conditions and improve its service performance. The invention provides a cooling coating and its preparation method and application.

Technical solution: cooling coating, including bottom layer, middle layer and surface layer, the bottom layer is a modified solvent-free sealing waterproof coating; by weight percentage, the middle layer includes 20-50% of polyurethane resin and 50-80% of functional materials; In terms of weight percent, the surface layer includes: 40-70% of organic-inorganic hybrid resin, 5-20% of reflective titanium dioxide, 1-5% of reflective black pigment, 3-10% of far-infrared radiation micropowder and 5-15% of solvent.

Preferably, the thickness of each layer of the coating is as follows: the bottom layer is 40-100 μm, the middle layer is 200-1000 μm, and the surface layer is 60-100 μm.

Preferably, the modified solvent-free sealing waterproof coating is a high-permeability concrete sealing coating prepared by small molecule epoxy.

Preferably, by weight percentage, the functional material includes: 30-70% of ultrafine phase change powder, 2-8% of airgel powder and 15-40% of hollow microsphere.

Further, the ultrafine phase change powder is a microcapsule with a phase change temperature of 40-50°C.

Preferably, in terms of weight percentage, the organic-inorganic hybrid resin includes metal silicate, and the proportions of siloxane chain segments are 10-15% and 5-10%, respectively.

Preferably, the reflective black pigment is a perylene film-containing black pigment with high near-infrared reflectivity.

Preferably, the far-infrared radiation fine powder is a high-temperature ceramic far-infrared radiation powder.

The preparation method of any one of the above cooling coatings, comprising the following steps:

(1) Primer preparation: Mix small molecule epoxy resin, reactive diluent, and concrete wetting agent in proportion, rotate at 300-500rpm, and disperse for 10-15min;

(2) Intermediate paint preparation: mix polyurethane resin, solvent and additives, stir at low speed, add functional materials, rotate at 300-500rpm, disperse for 30-50min;

(3) Topcoat preparation: Mix organic-inorganic hybrid resin, solvent and additives, stir at low speed, add functional materials, grind at least once with a horizontal sand mill, add the above additives and solvents again and stir at low speed;

(4) After treating the concrete surface, apply a primer to form a bottom layer. Apply an intermediate paint 30 minutes to 60 minutes after the primer is applied to form an intermediate layer. After 30 minutes to 60 minutes after the intermediate paint is applied, apply a topcoat to form a surface layer.

Application of any one of the cooling coatings mentioned above in high-speed rail ballastless track slabs.

The application of any one of the cooling coatings described above in the cooling and energy-saving protective coating of large stadium buildings, residential warehouses or ship vehicles.

The working principle of the cooling coating in the present invention is that the coating is composed of a bottom layer, an intermediate layer and a surface layer, and their functions complement each other to realize the multi-functional characteristics of the whole coating. The function of the bottom layer is concrete reinforcement, which is used to improve the positive tensile bond strength of concrete, and can be used on the surface of wet track slabs; the function of the middle layer is phase change control and heat barrier, which as the main body of the material gives the entire coating flexibility, The characteristics of heat insulation and phase change temperature control; the functional characteristics of the surface layer are solar heat reflection radiation, self-cleaning and ultra-long weather resistance, with ultra-high solar heat reflection coefficient and hemispherical emissivity.

Beneficial effects: (1) the positive tensile strength of the ballastless track slab concrete is enhanced by more than 50%; (2) the surface temperature of the concrete can be reduced by more than 15°C under hot sunlight; (3) the temperature difference between the upper and lower surfaces of the concrete can be reduced by more than 10°C; ( 4) The near-infrared reflectance of the cement-like color reaches more than 80%; (5) The coating has intrinsic self-cleaning performance and will not produce obvious attenuation; (6) The aging resistance of the coating is extremely strong, and the outdoor service life can be extended More than 30 years; (7) Phase change temperature control design is adopted to intelligently control the temperature of the protected object.

Description of drawings

Fig. 1 is the high-speed iron ballastless track slab structure schematic diagram that is coated with cooling coating of the present invention in embodiment 1;

Among them, 1 is the area coated with cooling coating, and 2 is the area not coated with cooling coating.

Detailed ways

The following examples further illustrate the content of the present invention, but should not be construed as limiting the present invention. Without departing from the spirit and essence of the present invention, the modifications and substitutions made to the methods, steps or conditions of the present invention all belong to the scope of the present invention. Unless otherwise specified, the technical means used in the embodiments are conventional means well known to those skilled in the art.

Example 1

The multifunctional intelligent cooling composite coating for high-speed rail ballastless track slab prepared according to the chemical composition of the coating is coated on the 1:1 high-speed rail ballastless track slab model as shown in Figure 1. The cooling test was carried out under sunlight, and the results showed that the average temperature difference between the top and bottom of the uncoated track plate was 25°C, and the average surface temperature was 60°C. After the coating is applied, the average surface temperature of the track plate is 44°C, and the surface temperature is reduced by 16°C. The temperature difference between the upper and lower surfaces is 12°C, and the temperature difference between the upper and lower surfaces is reduced by 13°C.

In addition, the average positive tensile bond strength of the uncoated concrete is 0.97MPa, the positive tensile average bond strength of the coated concrete is 3.23MPa, and the positive tensile bond strength of the surface of the coating reinforced track slab is 233%. After 5000 hours of QUV test on the concrete sample, the coating is intact, no blistering, cracking, falling off, etc., and the decrease in coating adhesion does not exceed 20%.

Claims (10)

1. The cooling coating comprises a bottom layer, an intermediate layer and a surface layer, and is characterized in that the bottom layer is a modified solvent-free sealing waterproof coating; by weight percentage, the intermediate layer includes 20-50% of polyurethane resin and 50-80% of functional materials %; by weight percentage, the surface layer includes: organic-inorganic hybrid resin 40-70%, reflective titanium dioxide 5-20%, reflective black pigment 1-5%, far-infrared radiation micropowder 3-10% and solvent 5-15% %. 2. The cooling coating according to claim 1, characterized in that the thickness of each layer of the coating is: the bottom layer is 40-100 μm, the middle layer is 200-1000 μm, and the surface layer is 60-100 μm. 3. The cooling coating according to claim 1, characterized in that, the modified solvent-free sealing waterproof coating is a small molecule liquid epoxy sealing coating. 4. The cooling coating according to claim 1, characterized in that, by weight percentage, the functional material comprises: 30-70% of ultra-fine phase change powder, 2-8% of airgel powder and Hollow microspheres 15-40%. 5. The cooling coating according to claim 4, characterized in that the ultrafine phase change powder is a microcapsule with a phase change temperature of 40-50°C. 6. The cooling coating according to claim 1, characterized in that, by weight percentage, the organic-inorganic hybrid resin comprises metal silicates, and the proportions of siloxane chain segments are 10-15% and 5-10%. 7 . The cooling coating according to claim 1 , wherein the reflective black pigment is a perylene film-containing black pigment with high near-infrared reflectivity. 8. The cooling coating according to claim 1, characterized in that, the far-infrared radiation micropowder is a high-temperature ceramic far-infrared radiation powder. 9. The preparation method of any one of claims 1-8, characterized in that, comprising the following steps: (1) Primer preparation: Mix small molecule epoxy resin, reactive diluent, and concrete wetting agent in proportion, rotate at 300-500rpm, and disperse for 10-15min; (2) Intermediate paint preparation: mix polyurethane resin, solvent and additives, stir at low speed, add functional materials, rotate at 300-500rpm, disperse for 30-50min; (3) Topcoat preparation: Mix organic-inorganic hybrid resin, solvent and additives, stir at low speed, add functional materials, grind at least once with a horizontal sand mill, add the above additives and solvents again and stir at low speed; (4) After treating the concrete surface, apply a primer to form a bottom layer. Apply an intermediate paint 30 minutes to 60 minutes after the primer is applied to form an intermediate layer. After 30 minutes to 60 minutes after the intermediate paint is applied, apply a topcoat to form a surface layer. 10. The application of any one of claims 1-8 in the cooling and energy-saving protective coating of high-speed railway ballastless track slabs, large stadium buildings, residential warehouses or ship vehicles.