The Core Features of Waterborne Acrylic Resin Used in Building Coatings Processing

With water as the dispersion medium, waterborne acrylic resin has become the mainstream film-forming raw material of architectural coatings (interior wall latex paint, exterior wall paint, waterproof coating, etc.) with its environmental protection performance and excellent construction and use characteristics. Its core features can be developed from the dimensions of environmental protection, construction adaptability, performance and application flexibility, as follows:

First, environmental protection and safety, in line with the trend of green building materials

Low VOC emission: Water-based acrylic resin replaces volatile organic solvents such as toluene and xylene in traditional solvent-based resin. The VOC content is usually ≤50g/L, and some high-end products can be as low as 10g/L, which is far lower than the national environmental protection standard for architectural coatings (GB 18582-2020). There is no pungent odor during construction and use, which reduces the harm to the atmospheric environment and human health and conforms to the "green building".

No fire safety hazard: water as a dispersed medium is non-flammable and non-explosive. Compared with solvent-based architectural coatings, water-based acrylic coatings do not need to worry about fire risks during storage, transportation and construction, which reduces the safety control cost of storage and construction, and is especially suitable for painting projects in densely populated areas such as residential buildings and office buildings.

Convenient wastewater treatment: the tool cleaning wastewater generated in the construction process can be discharged up to the standard only by simple precipitation and filtration treatment, and there is no water pollution problem caused by organic solvents, which meets the strict requirements of environmental protection policy on industrial wastewater discharge and reduces the environmental protection pressure of coating enterprises.

Second, the construction performance is excellent, and it is suitable for architectural painting scenes.

Flexible construction method: Waterborne acrylic resin coating can be applied in various construction methods, such as brush coating, roller coating, spray coating, etc. The construction viscosity is easy to adjust, and the leveling performance is good (leveling time is less than or equal to 30 minutes), and defects such as brush marks, sagging and bubbles are not easy to occur. Even non-professional construction personnel can operate it, and it is suitable for different construction scenes such as home decoration and large-scale construction projects.

Fast drying speed: in the normal temperature (25℃, relative humidity 60%) environment, the surface drying time is only 1-2 hours, and the practical work time is less than or equal to 24 hours, which can realize rapid recoating (the next painting can be carried out at intervals of 4-6 hours), greatly shorten the construction painting period, and is especially suitable for projects that are greatly affected by weather, such as exterior wall painting, and reduce the risk of delay in rainy days.

Strong adaptability to substrate: it can be directly painted on the surfaces of various building substrates such as concrete, cement mortar, gypsum board, wood and metal, without complicated substrate pretreatment (only cleaning, drying and removing floating ash), with strong adhesion (tensile strength ≥1.5MPa), and it is not easy to peel off and fall off, so it is suitable for the painting requirements of different parts such as building walls, ceilings, doors and windows.

Low-temperature construction is friendly: partially modified waterborne acrylic resin (such as adding film-forming additives) can form a film normally in an environment above 5℃. Compared with the lowest construction temperature of solvent-based coatings (above 10℃), it adapts to the construction needs in the low temperature period in northern China in spring and autumn, and expands the construction window period.

Third, the use performance is comprehensive, ensuring the quality of architectural painting.

Outstanding weatherability: the acrylate group contained in the molecular structure of waterborne acrylic resin has excellent anti-ultraviolet degradation ability. After being used, the exterior wall coating can resist the natural environment erosion such as wind, sun and rain, and can keep the color stability (color difference δ E ≤ 2) and the paint film intact without pulverization, cracking and fading after being exposed to the outdoor for a long time (5-8 years). It is especially suitable for outdoor scenes such as exterior walls, bridges and squares of high-rise buildings.

Strong scrub resistance and stain resistance: after the paint film is cured, a dense polymer film is formed, and the scrub resistance of interior wall latex paint can reach more than 10,000 times, and daily stains (such as dust, juice and oil stains) can be directly wiped off by a wet cloth without damaging the paint film; The surface of exterior wall coating has certain hydrophobicity (contact angle ≥ 90), which can reduce the stain residue after rain washing and keep the wall clean and beautiful.

Good flexibility and crack resistance: by adjusting the glass transition temperature (Tg value) of resin, the flexibility of paint film can be customized (elongation at break≥100%), which can adapt to the slight deformation of building base materials (such as concrete and gypsum board) due to temperature change and settlement, and avoid paint film cracking; It is especially suitable for painting new building walls (prone to shrinkage and deformation) and old buildings (prone to cracking of base materials).

Excellent anti-mildew and anti-bacterial performance: the water-borne acrylic resin coating can be added with environmental-friendly anti-mildew agents (such as isothiazolinone) to inhibit the growth of mold and bacteria in humid environment (such as bathrooms, basements and southern rainy season), and the paint film has no mildew spots and odor, which ensures indoor air quality and meets the sanitary requirements of houses, hospitals, schools and other places.

Fourth, the application is flexible, adapting to the needs of multi-painting.

Strong function customization: By adjusting the monomer ratio (such as introducing methyl methacrylate and butyl acrylate) and adding functional additives (such as flame retardant, waterproof coating and antistatic agent), building coatings with multi-functions such as fire prevention, waterproof, antistatic and heat preservation can be developed. For example, water-based acrylic waterproof coating can be used in waterproof engineering of roofs, toilets and basements, and it has no seam after film formation and good water resistance and permeability; Fire-retardant waterborne acrylic coatings can be used in steel structure buildings to improve the fire resistance limit.

A wide range of colors and glosses can be selected: water-based acrylic resin has good compatibility with pigments, and thousands of colors can be blended, and the colors are even and bright, which can meet the decorative needs of different architectural styles (modern simplicity, Chinese classicism and European luxury); The gloss can be adjusted to matte, mercerized, semi-gloss, high-gloss, etc. according to requirements, and it is suitable for different scenes such as interior wall (mainly matte, eye protection) and exterior wall (mercerized/semi-gloss, easy to clean).

Good compatibility with other materials: it can be combined with polyurethane, epoxy resin, silicone-acrylic resin, etc., or used in coordination with various environmental protection additives such as water-based color paste, film-forming additives and defoamer to further optimize the performance of paint film (such as improving weather resistance, hardness and adhesion), develop high-end architectural coatings products (such as imitation stone paint, real stone paint and artistic paint), and enhance the grade and added value of architectural decoration.

Five, high cost performance, in line with the project cost requirements.

The cost of raw materials is controllable: the main raw materials of waterborne acrylic resin (acrylic monomer, water and initiator) are widely available, the production process is mature, and the cost is relatively stable after large-scale production. Compared with high-end solvent-based resins (such as fluorocarbon resins) and silicone-acrylic resins, it has obvious cost advantages and is suitable for the coating needs of large-scale construction projects.

Low cost of construction and maintenance: there is no need to equip explosion-proof equipment and ventilation equipment in the construction process, and only water is needed for tool cleaning, which reduces the auxiliary cost of construction; The paint film has a long service life (5-10 years for the interior wall and 8-15 years for the exterior wall), and only local repair is needed in the later maintenance without overall renovation, which greatly reduces the long-term maintenance cost of architectural painting.

To sum up, water-borne acrylic resin, with its core characteristics of environmental protection, safety, convenient construction, comprehensive performance and high cost performance, perfectly meets the processing and application requirements of architectural coatings, and has become the key material for the construction industry to realize green and low-carbon transformation and improve the coating quality, and is widely used for interior and exterior wall decoration and functional protection of various buildings such as houses, office buildings, bridges and gymnasiums.