Study on nano-thermal insulation and environmental protection packaging coating material (I)

The nano thermal insulation and environmental protection coating material is an acrylic nanoemulsion and a water-based thermal reaction thermal insulation coating material made of acrylic nanoemulsion, which can effectively reflect infrared rays, reduce the absorption of thermal energy by packaging materials, and change the coating material content. A large number of organic solvents, poor thermal insulation, technical problems, with anti-corrosion, waterproof, heat insulation, non-flammable, non-explosive, pollution-free, is an ideal green environmental protection packaging materials.

New materials are the material basis and important support for the development of high technology. Their development has gone far beyond their own scope, and has affected the development of various disciplines and the innovation of products. Among them, nanomaterials have become a research hotspot in materials science at home and abroad.

In the past when we were studying the nature and structure of materials, we stayed in the micron stage (ie 10-6 meters) for a long time. Within this range of magnitude, there are major deficiencies in the properties and structure of the material. Nanomaterials are ultrafine particles of nanometer size (10-9 meters) (1-15 nanometers) size, artificial condensed solids formed by pressing, sintering or sputtering, advanced in the 1980s. material. In the mid-1980s, material scientists from Germany and the United States first produced this material in the laboratory, which was hailed as "the most promising material in the 21st century." The United States "Time Magazine" selected nanomaterials as one of the "ten technologies that are most likely to make great changes in humanity in the next 10 years." Research on the application of nano-particles in coatings has led the United States to the forefront of the world, and several companies have achieved the commercialization of nano-coating products.

The unique properties of nanomaterials

1, the third solid state structure

Nanomaterials have a special structure. Since the nanoparticle-constituting ultrafine particles are on the order of nanometers in size, this magnitude is much closer to the basic structure of the material—the molecules and even the atoms. The proportion of atoms at the interface is extremely large, generally accounting for about 50% of the total number of atoms. Regardless of whether the ultrafine particles are composed of crystalline or amorphous substances, the structure of the interface atoms is not only different from long-range ordered crystals, but also Different from the long-range disorder, short-range order gas-like solid structure. Therefore, some researchers have referred to nanomaterials as "third-state solid materials" other than crystalline and amorphous.

2, unusual odd characteristics

Because of this special structure of nanomaterials, the material itself has a small size effect, a surface interface effect, a quantum size effect, and a macro quantum tunnel effect, so that it has many physical and chemical properties different from traditional materials. For example, the fracture stress of nano-iron materials is 12 times higher than that of conventional iron materials; the diffusion rate of gas through nano-materials is several thousand times faster than that of common materials; copper is no longer conductive after nano-scale and thermal diffusion is enhanced compared to conventional copper materials. Nearly double; cutting tools made of certain nano materials are harder than diamond products. It has also been found that the shape of nanoparticles gradually changes, and the smaller the particle size, the stronger the change. In nanomaterials, there are large particles that “join” small particles; the physicochemical interaction between nanoparticles and biological cell membranes is strong and they can be swallowed by cells. Due to these peculiar properties of nanomaterials, such as force, electricity, light, magnetism, absorption, catalysis, and sensitivity, it has a wide and attractive application prospect.

Complete nano-coating materials are now used in packaging. With the traditional coating technology, adding a small amount of nano-materials or forming nanoparticles on-line, the function of the traditional coating can be upgraded: increase the hardness, reduce the formation of friction Self-moistening, and improve high temperature resistance, oxidation resistance and aging resistance. It can also produce antibacterial and cleaning effects.

Experiments and preparation of raw materials

Preparation of Aqueous Thermal Reflective Insulation Coating Material Made from Acrylic Nanoemulsion

In order to solve the technical problems that the existing coating may cause environmental pollution due to a large amount of organic solvents, and have poor heat reflection and heat insulation, a water-based thermal reflective heat insulation coating was developed. The raw materials include: acrylic nanoemulsion, conventional acrylic emulsion, Pigments, fillers, infrared reflectors, additives, PH regulators, thickeners, demineralized water, weight ratio: (15-25); (15-25); (1-20); (5-20); (0.1 - 1); (1 - 10); (0.5 - 2.5); (0.1 - 0.5); (0.2 - 1.5); (20 - 40). Does not contain organic solvents.

Hollow microspheres include one or more of hollow ceramic microspheres, hollow glass microspheres, and power-plant floating beads. Power plant drift beads are a by-product of cinder from power plants. Hollow glass microspheres are prepared from boron glass having a low degree of hydrolysis.

Pigments include one or more of iron oxide black, red iron oxide, yellow iron oxide, titanium white, indigo blue, indigo blue, and light yellow. It is required that the selected pigment has low infrared absorption or high infrared reflectivity.
Fillers include one or more of light calcium carbonate, precipitated barium sulfate, talc, and mica powder.

The infrared reflective agent is a nanometer-sized oxide fine powder of nano titanium oxide fine powder and/or precious metal niobium, tantalum, niobium.

Thickeners are polyether and/or alkali soluble acrylic emulsion associative thickeners.

Additives include dispersants, wetting agents, leveling agents, defoamers, anti-mold agents, preservatives. The choice of dispersant depends on the nature of the pigment. For inorganic pigments such as titanium dioxide and iron oxide red, sodium, ammonium and amine salts of copolymers of alkenyl monomers with unsaturated carboxylic acids and their esters can be used. For example: Germany Henkel's 5040 and 5027 dispersants and Rohm and Haas's T-731 dispersants are used in an amount of 0.5-2% of the amount of pigments. For organic pigments such as indigo blue, high pigmented groups can be used. Molecular block copolymers, such as Byk184 from BYK GmbH or EFKA-550 from Effka, the Netherlands, are used in an amount of 5-20 % of the pigment amount; wetting agents use polyether modified acetylenic alcohols such as American Gas Chemistry. The company's SURFYNOL GA, SURFYNOLTG, the amount of coating for the 0.1-0.3%; leveling agent can be selected silane or fluorocarbon modified polyether, such as Germany's BYK company's Byk348, 307, the Netherlands Effka company's EFKA-3570 Defoamers are selected from polyether-modified silicones, such as SN313, NXZ, NDW from Henkel, Germany, BYK024 from BYK, with an amount of 0.01-0.1% of the coating amount; the preservative can be Oriental-Rohmer Haas. The company's KATHON LXE, for the amount of paint 0.1-0.3%; fungicide East - Rohm and Haas Company SKANEM-8, Xuzhou pesticide factory BCM fungicide, in an amount of 0.1-0.5% of the amount of paint. The pH regulator is a volatile base such as: ammonia, 2-amino-1-propanol, N-methylmorpholine, N-ethylmorpholine, triethylamine, N,N dimethylethanolamine. Thickeners are polyether or alkali soluble acrylic emulsion associative thickeners such as TT935 thickener from Beijing Dongfang-Rohm and Haas company, and Rh-278 thickener from Velos Corporation. Demineralized water is deionized or distilled water, in which the total amount of water-soluble substances is <100 ppm and the conductivity is <20 μs/cm.