Research on nano-thermal insulation and environmental protection packaging coating material (2)

Experiment and preparation method

Preparation method of acrylic nanoemulsion

1. Add the first mixture of unsaturated monomer, solvent and initiator in the reaction vessel No. 1 and stir and nitrogen gas. Warm up to 80-110° C. and incubate for 1.5-2 hours. The first unsaturated monomer contains Methyl propionate, butyl acrylate, butyl methacrylate, methacrylic acid, and acrylic acid. Their weights are: (10-20), (6-20), (0-10), (0) -1), (0 - 1); the parts by weight of solvent and initiator are: (6-10), (0.3-1);

2. The second mixture of unsaturated monomer, solvent and initiator is added dropwise into the No. 1 reaction vessel, and the dropping time is 0.5-1 h, and 1-1.5 h is maintained at 80-100° C.; Unsaturated monomers include methyl methacrylate, butyl acrylate, butyl methacrylate, methacrylic acid, and acrylic acid, and their weights are: (10-20), (6-20), (0-10) ), (0-1), (0-1); parts by weight of solvent and initiator are: (6-10), (0.3-1):

3. The third mixture of unsaturated monomer, solvent and initiator is uniformly added dropwise into the No. 1 reaction vessel. The dropwise addition time is 0.5-1 h, and the incubation is performed at 80-110° C. for 1.5-2 h; the third part is not The saturated monomers include methyl methacrylate, butyl acrylate, butyl methacrylate, methacrylic acid, acrylic acid, maleic anhydride, and their weights are: (10-30), (8-20) (0-10), (0-2), (0-2), (0-2); parts by weight of solvent and initiator are: (8-10), (0.4-1):

4. Add PH regulator and demineralized water to No. 2 reaction vessel, stir, transfer the material in No. 1 reaction vessel to No. 2 reaction vessel, stir and emulsify for 1-2h; the weight of PH regulator and demineralized water The order is: (3-7), (100-150):

5. The material obtained in step 4 is pumped out of the solvent and filtered to remove larger particles to obtain an acrylic nanoemulsion, the vacuum degree may generally be 500-700 mmHg, and the filtration may be performed using a 100-150 mesh filter. Good use of 120 mesh filter. The main component of the acrylic nanoemulsion obtained in Step 5 is an acrylic copolymer having a number average molecular weight of 20,000 to 100,000, and a number average particle size of more than 95% in a range of 10 to 100 nm;

6. Add demineralized water, auxiliary agent, infrared reflector and acrylic nanoemulsion in the slurry container and mix well; use the adjustable high-speed disperser to stir; the following steps 7, 9 and 10 are the same;
7. Add pigment and filler to the mixture obtained in step 6, and mix well;

8. The mixture obtained in step 7 is ground to a fineness of 30 μm or less to obtain a color paste, which is ground using a ball mill or a sand mill;

9, in the paint container by adding color paste, hollow beads and conventional acrylic emulsion, stir evenly;

10. Add a thickening agent to the mixture obtained in step 9 and mix well;

11, in the step 10 in the mixture obtained by adding PH regulator, adjust the PH value to 8-10;

12. The mixture obtained in step 11 is filtered and the larger particles are filtered to obtain a water-based thermal reflective insulation coating. Use 60-100 mesh filter, preferably 80 mesh filter.

Excellent performance

Compared with common paints and existing solvent-based heat-reflective coatings, it has the following advantages: 1 Excellent heat reflection and heat insulation. Since the water-based thermal reflective insulation coating contains infrared reflectors and hollow microspheres, the former can reflect infrared rays in the light, the latter's surface can reflect light, the middle hollow can be insulated, and the water-based thermal reflective insulation coating can reflect 50 - 80% of the solar thermal energy, significantly reduce the temperature within the container or room; 2 safe and convenient to use, non-flammable, non-explosive, pollution-free. Acrylic nano-emulsion and water-based heat-reflecting heat-insulating coatings use water as a dispersion medium, do not contain organic solvents and auxiliary solvents, do not cause environmental pollution, do no harm to the human body, improve the construction environment, and avoid potential fire hazards. 3 good decoration. The base material of the water-based thermal reflective insulation coating is a conventional acrylic emulsion and an acrylic nanoemulsion. The latter has a small particle size and can fill the gap between the former latex particles to obtain a uniform, delicate and highly decorative coating material. 4 The overall performance of the paint film is good. As in the water-based thermal reflective insulation coating, the conventional acrylic emulsion and the acrylic nanoemulsion have reasonable matching and dense film formation, and the paint film adhesion, mechanical properties, water resistance, alkali resistance, and weather resistance are all good. With excellent freeze-thaw stability.

Implementation case

As shown in Table 2, Examples 1 to 6 are the raw material ratios of the six acrylic nanoemulsions, respectively.

In Table 2, benzoyl peroxide is an initiator, n-butanol is a solvent, triethylamine, 2-amino-1-propanol, and N,N-dimethylethanolamine are pH regulators.

According to the above implementation example, the manufacturing method of the implementation example 4 will now be described as follows. The manufacturing method thereof includes the following steps:

1. Add the first mixture of unsaturated monomer, solvent and initiator in the No. 1 reaction vessel, stir and nitrogen, heat to 80-110°C for 1.5-2 hours. The first unsaturated monomer contains A. Methyl acrylate, butyl acrylate, butyl methacrylate, methacrylic acid, their weights (g) are: 100, 200, 100, 8; n-butanol is used as the solvent, weight is 7 g, and the initiator is used Benzene oxide, weight 1.0g.

2. The second mixture of unsaturated monomers, solvent and initiator is added dropwise into the No. 1 reaction vessel. The dropwise addition time is 0.5-1 h, and 1-1.5 h is maintained at 80-110° C.; The unsaturated monomers include methyl methacrylate, butyl acrylate, butyl methacrylate, and methacrylic acid. Their weights (g) are: 75, 150, 75, and 12; the solvent is n-butanol, and the weight is 8g, the initiator used benzyl peroxide, weight 0.5g.

3. The third mixture of unsaturated monomer, solvent and initiator is uniformly added dropwise into the No. 1 reaction vessel. The dropwise addition time is 0.5-1 h, and the incubation is performed at 80-110° C. for 1.5-2 h; the third part is not Saturated monomers include methyl methacrylate, butyl acrylate, butyl methacrylate, acrylic acid, maleic anhydride, and their weights (g) are: 75, 150, 75, 10, 10; solvent is positive Butanol, 10 g in weight, benzoyl peroxide as initiator, weight 0.5 g.

4. The pH adjuster and demineralized water are added to the No. 2 reaction vessel, stirred, the material in the No. 1 reaction vessel is transferred to the No. 2 reaction vessel, and emulsified by stirring for 1 to 2 hours; wherein: the pH adjuster uses triethylamine And N,N dimethyl ethanolamine, both of which have a weight of 3 g, the weight of demineralized water is 150 g.

5. The material obtained in step 4 is evacuated to remove solvent, the vacuum degree of the vacuum is 500-700 mmHg, and is filtered with a 120-mesh copper filter, and larger particles are filtered to obtain an acrylic nanoemulsion.

Mechanism of action

The mechanism of action of nano-TiOx on coatings is: nano-TiOx particles are small, have large specific surface area, many surface atoms, high surface energy, and insufficient coordination of surface atoms, have strong surface activity and super-adsorption capacity, and are added to coatings. , It is easy to cooperate with the oxygen in the resin to increase the bond strength between the molecules and the construction performance of the coating and the bonding strength between the coating film and the substrate. Nano TiOx has special optical characteristics that are not available in conventional materials, and is generally The phenomenon of "blue shift" exists, and the reflectivity to ultraviolet long-wave, medium-wave and infrared rays is as high as 85%, and the optical reflection spectrum of nano-TiOx is reproducible. Therefore, the purpose of shielding ultraviolet rays can be achieved by adding in the coating, and the anti-aging of the coating can be greatly improved. Performance; The small size effect of nano-TiOx makes it produce siltation, forming a dense "nano-coating film" at the coating layer interface, greatly improving the washability of the coating and the self-cleaning property of the coating film surface; the unique space network of nano-TiOx. In the structure, there are a large number of unsaturated residual bonds and hydroxyls in different bonding states on the surface, which can produce a good affinity with the coating system. Good suspension stability of the coating. After the coating is dried, the nanoparticles are scientifically arranged to form a complete air insulation layer.

application

1, product characteristics

Nanometer environmental protection thermal insulation coating material is a special emulsion paint developed and produced using advanced nanotechnology. It has an excellent ability to reflect infrared rays and its unique microporous structure to form a thermal insulation layer. In summer, the temperature can be lowered. Winter Can reduce heat loss, "Winter warm and cool in summer" to save energy; use the international standard color, can achieve any color. And with good adhesion, high elasticity and compactness, waterproof, anti-corrosion, sound insulation and other functions. Painted in wet and wet surfaces, the product's life span can be as long as 10 years. After more than two years of product coating on the roof of the plant, external walls, petrochemical equipment, storage tanks, storage tanks, pipelines, trunks, containers, ships, movable board rooms, warehouses, cold storage, etc., it has a very good effect and achieves better results. The social benefits and considerable economic benefits. It is an environmentally friendly green packaging material.

2, product performance indicators

Project Indicators
Dry ≤30 min
Drying time ≤24h
Contrast ratio ≥ 0.93
Alkaline resistance (24h) No abnormality
Water resistance (48h) No abnormality
Washability, >2000
3, operation requirements
Density: about 1.3g/cm3
Dry film thickness: ≥ 30um / wet film thickness: 60-80um / channel theoretical usage: 110-140g / m2
Drying time (standard environment): Table dry ≤ 1h, hard dry ≤ 24h
Coating interval:

Coating number: 2 tracks, dry film thickness ≥ 60um;
Surface treatment: batch scraping propylene