The development and application of nano-modified coatings

China Paint Online News Information:
Division Xiaomei (Taiyuan City Construction Engineering Quality Supervision Station, Shanxi Taiyuan 030009)
Summary: Adding functional nanomaterials to the coating not only improves the traditional properties of the coating, but also gives the coating many new properties. Nano-modified coatings have greatly improved the conventional technical properties of coatings, and can improve the properties of coatings aging, corrosion resistance, radiation resistance and so on.
key words: nanomaterials; Waterproof paint; Anti-aging; Ultraviolet
: TQ 630. 7; TU 767． 1 Document identification code: A
article number: 1009 - 9441 (2014) 01 - 0026 - 02
Introduction
With the rapid development of China's economy, the construction industry has become one of china's major industries. With the improvement of people's living standards, the building conditions of the past have been far from meeting people's needs. In people's many needs, architectural coatings play an important role. Since the beginning of the 21st century, people demand that architectural coatings have better durability, low pollution and antibacterial anti-fouling properties, which pose great challenges to China's current architectural coatings and construction processes. Therefore, the development and application of high-level architectural coatings and construction technology has become a hot research topic in many disciplines today. With the rapid development of nanotechnology and nanomaterials, nanomaterials have been applied to all aspects of the construction industry, such as concrete, cement, coatings and other basic materials, transforming the development of the traditional construction industry, so that building materials have a new function and mission.
1 Nano-modified coatings with different functions
nano-modified coatings not only have various superior properties of traditional coatings, but also make traditional coatings have many new functions, such as antibacterial, self-cleaning, anti-static, stealth, purifying the atmosphere, high transparency and so on. If nano-modified coatings are classified by function, they can be divided into the following categories.
1． 1 nanometer antibacterial coating
nomethic antibacterial materials have been widely used in fiber, plastics, ceramics and electrical appliances, used to kill E. coli, Staphylococcus aureus and other bacteria and viruses. Inner wall coatings and coatings for a variety of instruments, furniture surface, due to frequent contact, there will be a large number of bacteria and viruses on its surface, easy to cause cross-infection, therefore, it is necessary to develop nano-modified antibacterial coatings. At present, nanomaterials with good antibacterial properties mainly refer to nano TiO2, nano ZnO and nano-silver-carrying materials.
1． 2nm modified waterproof coating
special nano-interface coating has excellent anti-corrosion and self-cleaning function, is a very important coating varieties, especially in the metal anti-corrosion is of great significance. According to statistics, the quality of steel products scrapped by corrosion in the world each year is equivalent to about 1/3 of steel production, of which about 10% of the annual output of steel into rust, which is a huge loss of resources and energy. Therefore, how to use science and technology to prevent, control or reduce the corrosion of steel materials economically and safely is of great significance to China's economic construction and development.
1． 3 Anti-aging nano-
to improve the weather resistance of external wall coatings is one of the development directions of exterior coatings. Nanoscale pigments have been greatly improved in weather resistance, nano-scale pigment particles can absorb ultraviolet light, so this material can play the role of ultraviolet absorbers, can effectively enhance the anti-aging properties of coatings. Nano ZnO, SiO2, TiO2, Fe2O3, CaCO3 and other particles have special optical properties not available to large particles, the prevalence of "blue shift" phenomenon, added to the coating can form a shielding effect on the coating, so as to achieve the goal of anti-UV aging. NanoTiO2 can be added to the coating according to a certain proportion, can be made a special anti-ultraviolet product ———nomet coating, and nanomaterials can enhance the adhesion of the coating and substation, so that it has anti-color effect, and can make the coating itself into a decorative material.
add a certain amount of nanoSiO2 to the coating can also play a very good role. NanoSiO2 is an anaerical white powdery substance with good optical properties such as UV absorption and reflective infrared, and its absorption and reflectivity of ultraviolet and infrared light with wavelengths of less than 400 mm and infrared waves above 80 mm are as high as 70%. NanoSiO2 molecular structure has a large number of unsaturated bonds, the presence of these unsaturated bonds show strong activity, can absorb some colored particles, which to a certain extent reduces the paint under ultraviolet radiation produced pigment attenuation.
2. The effect of nanomaterials on coating
2. 1 nanometer SiO2
effect on coating performance After adding the appropriate amount of nanoSiO2 to the interior and exterior wall coatings of the building, the anti-UV anti-aging performance of conventional coatings was improved by 2. More than 5 times; Scrub resistance is more than 10 times higher than before. NanoSiO2 in the internal and external wall coatings in the amount of addition is generally 0. 1% to 1%, up to ≯5%. NanoSiO2 has a very strong UV shielding, the UV shielding rate for the long Bosnia-Herzegovina spot effect reaches 88%, while the UV shielding rate for the medium wave erythema effect is 85%, and the short-wave shielding rate for sterilized UV rays is still 70% to 80% ( Because of the low penetration of this short wave, nanoSiO2 in the coating can play a role in shielding a variety of ultraviolet rays, so as to achieve the purpose of the coating anti-UV aging and heat-resistant aging.
2． The effect of 2nm TiO2
on coating performance compared with conventional materials, nanoTiO2 has several unique properties: (1) larger than the surface area; (2) Strong magnetism; (3) Light absorption is good, and the ability to absorb ultraviolet light is strong; (4) large surf activity; (5) good thermal conductivity; (6) Good dispersion, stable suspension, etc. Because nanoTiO2 has many excellent performance, it has a broad application prospect in the field of coatings.
construction coatings, especially exterior coatings, the application environment is relatively harsh, ultraviolet, thermal energy, microorganisms, water, air pollutants can cause the aging of polymers in the coating, which in turn with ultraviolet aging is the most destructive. Therefore, the key to improving paint weather resistance is how to reduce the degradation of coatings by ultraviolet light.
2． Effect of 3nmZnO on coating performance
nNO is also an excellent anti-aging agent added to the coating, adding a certain amount of nano ZnO to the coating can significantly improve the anti-aging performance of the coating. Nano ZnO's ability to absorb ultraviolet light is stronger than other nanomaterials, whether it is on the long Bosnia-Herzegovina spot effect UV, or on the medium wave erythema effect UV, have a better shielding effect, so it is suitable as an anti-aging agent in the coating. Japan's patent reports that Itogang and other researchers used a certain amount of ZnO as a glass additive, developed a glass with ultraviolet shielding coating.
. Foster Products uses nanoZnO to create an anti-aging coating that is 15 times more resistant to aging than conventional coatings. Another U.S. company used Foster Products' nanoZnO to successfully create a UV-resistant pre-mixture with solvents, resins, catalysts, etc., which can be used as a vital part of coatings and plastic formulations.
2． Effect of 4 nanometer clay on coating performance
Clay is a "one-dimensional" nanomaterial, so it is higher than the surface area relative to other nanomaterials, up to 700 to 800 m2 /g. Clay as an additive in composite materials is also extremely widely used, depending on the amount of added to composite materials, can be made the following products: conventional composites, laminate composites and peeling composites. Adding the right amount of clay to the coating can greatly improve the mechanics and thermal performance of the coating. Changing clay and adding it to the coating not only improves the flexibility and impact resistance of the coating, but also improves the optical properties of the coating to a certain extent, resulting in a new type of architectural coating.
3. The
coating is an ancillary product of industrial products, and its application range is very wide. It can be said that any kind of industrial products can not be separated from paint. The 21st century is the era of information industry, coatings have a new application area. For example, an electro-excitation optical element, which clamps a fluorescent material between two electrodes and, when an intersection/DC biased electric field is added, its fluorescent electrons are affected and sent in the form of energy transfer. It is divided into non-electromechanical light-emitting elements and mechanical and electrical light-emitting elements. This component has the advantages of cold light, no heat and no UV damage, less power consumption, waterproof and anti-humidity, vibration, shock resistance, many kinds of light color, uniform lighting and its strength adjustable and long service life, etc. , can be used for computers, household appliances, equipment, instruments and other liquid crystal backlights, as well as automobiles, transportation, construction, advertising and other signs display and colorful, full-color display, etc.
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