1. Water-based silicone-acrylic emulsion
Our conventional paints for interior and exterior walls have the same composition - an emulsion. Emulsions play an important role in architectural coatings. There are currently three types of emulsions on the market, namely silicone-acrylic emulsion, pure acrylic emulsion, and styrene-acrylic emulsion.
Now let's briefly introduce the difference between these three lotions:
1. Composition difference
Silicon-acrylic emulsion: polymerized from silicone monomers containing unsaturated bonds and acrylic monomers, silicone + acrylic acid (acrylate) + additives;
Pure acrylic emulsion: polymerized from acrylic monomers such as: various acrylic acids + methacrylic acid + methyl methacrylate + acrylates + additives;
Styrene-acrylic emulsion: polymerized from styrene monomer and acrylic monomer, styrene + acrylic acid (acrylate) + additive
2. Price difference
Market reference prices are as follows:
Styrene-acrylic emulsion: 9500 yuan/t, the current price is mainly 5000-8500 yuan/t, there are also quality ones, such as Dow's and BASF, the price is 12000 yuan/t
Pure acrylic emulsion: 12,500 yuan/ton, pure acrylic usually costs 15,000-18,000 yuan/ton
Silicone-acrylic emulsion: 16,000 RMB/ton, the price of high-quality and high-purity silicon-acrylic emulsion reaches 25,000 yuan/ton.
3. Service life difference
The service life of styrene-acrylic emulsion is 4-5 years, and the service life of household styrene-acrylic emulsion is usually no more than 3 years.
The service life of pure acrylic emulsion is more than 10 years,
The service life of silicone-acrylic emulsion is more than 15 years.
Note. In architectural coatings, the higher the emulsion content, the longer the service life. Generally, more than 8% of the emulsion content is qualified and more than 10% is high quality.
4. Difference in benefits
Advantages of silicone acrylic emulsion: strong acid and alkali resistance, film formation is not easy to yellow, film particles have high tensile strength, high flexibility, and not easy to bleach when exposed to water;
Advantages of pure acrylic emulsion: difficult to burn, high gloss, wide applicability;
Advantages of styrene-acrylic emulsion: low price, high melting film formation rate and low temperature design.
5. different market share.
According to data published by the paint industry, the market share of various emulsions is roughly as follows:
Pure acrylic emulsion 40%
Silicone acrylic emulsion 35%
Styrene-acrylic emulsion 14%
Other lotions 11%.
Generally speaking, silicone-acrylic emulsion or pure acrylic emulsion is generally chosen for home improvement and utility construction, considering the service life of the exterior wall. If styrene-acrylic emulsion is used for the outer wallThis means that the outer wall does not place high demands on the service life of the paint.
So besides the three main types of lotions, what other lotions are there?
Vinegar Acrylic Emulsion, Tertiary Acrylic Emulsion, Tertiary Acrylic Vinegar Emulsion, Tertiary Acrylic Emulsion, EVA Emulsion, Water Based Fluorocarbon Emulsion, etc.
Acrylic Acetic Emulsion: Also known as ethylene propylene emulsion, it copolymerizes with vinyl acetate and butyl acrylate as the main functional monomers and is suitable for making interior wall paints and mercerized paint emulsions. This emulsion has low cost, poor water resistance, creep resistance, alkali resistance and aging resistance.
Vinegar emulsion: copolymer of vinyl acetate and vinyl tertiary carbonate, since the reactivity ratio of vinyl tertiary carbonate and vinyl acetate is the same, it can be used to synthesize high performance tertiary vinegar emulsion, tertiary vinegar acrylic emulsion, which can greatly improve the adhesive. Excellent cohesion, water resistance and permeability while reducing emulsion surface tension and making polymer emulsions with small particle sizes. Widely used in woodworking adhesive, packaging adhesive, tile adhesive, PVC leather adhesive, etc.
Tertiary acetate-acrylic emulsion: terpolymerized tertiary ethylene carbonate, vinyl acetate and acrylate, which can be used to produce high strength and environmentally friendly water-based metal surface coatings, plastic surface coatings and wood surface coatings.
T-Acrylic Emulsion: Polyethylene tert-carbonate and acrylic acid (acrylate) polymerize. It has excellent anti-corrosion characteristics of metal, adhesion, hydrophobicity and water resistance; high price; suitable for industrial outdoor corrosion protection. paint.
EVA emulsion: short for vinyl acetate-ethylene copolymer emulsion, is a polymer emulsion formed by copolymerizing vinyl acetate and vinyl monomers with other auxiliary materials through emulsion polymerization. The EVA emulsion has permanent flexibility. EVA emulsion can be considered as an internal plasticized product of polyvinyl acetate emulsion. Since it introduces ethylene molecular chains into polyvinyl acetate molecules, the acetyl group creates breaks, increases the freedom of rotation of the polymer chain and sterically prevents small, the main polymer chain becomes soft, and plasticizer migration does not occur, which ensures constant softness of the product.
Water-based fluorocarbon emulsion: It is polymerized with organic fluorine, (meth)acrylate, special wet adhesion monomer, reactive emulsifier, etc. using advanced seed technology and core-shell technology, and has excellentoh stain resistance. Durability, superweather resistance and chemical resistance are 3-5 times higher than conventional emulsions.
Second, rutile titanium dioxide
The scientific name for titanium dioxide is titanium Dioxide, which has two crystalline forms: rutile and anatase.
Titanium dioxide has three crystal structures: brookite, anatase and rutile.
Because of its unstable crystal structure, brookite cannot stably exist in nature for a long time, so a small amount has no industrial value and is not used.
What advantages does rutile have over anatase?
1. Differences in Grain Size and Dispersion: Since the crystalline form of rutile products tends to be hexagonal, it is easier to disperse uniformly than anatase, and the agglomerates formed by it are more uniform and the particle size distribution is narrower. .
2. Whiteness and coloring power: The whiteness of titanium dioxide in anatase is better, but the coloring power is only 70% of that of rutile.
3. Weather Resistant: Just one year after adding an anatase titania sample, it will begin to crack or flake off, while adding a rutile titania sample will change its appearance only slightly after ten years.
Conclusion: The crystalline form of rutile titanium dioxide is better and more stable, the particle size distribution is narrower, it is easier to disperse evenly, the coloring power and weatherability are better, and the whiteness of titanium dioxide in anatase is higher. .
Compared to rutile titanium dioxide, there is no surface treatment process in anatase titanium dioxide, and the crystal forms of the two are also different; for products with high weather resistance, only rutile titanium dioxide can be used, and anatase is mainly used for products with low weather resistance requirements and high whiteness requirements
Anatase unit cell (upper left), rutile unit cell (upper right), anatase crystal cluster (lower left), rutile crystal cluster (lower right)
Use the Diamond software to demonstrate the spatial structure of the anatase and rutile unit cell. The octahedron (TiO6) in the unit cell of anatase (Ti4O8) is connected by two common edges in the non-red plane and several identical octahedra Comply with the principle of minimum steric hindrance, finally form a long chain in a zigzag structure, and the chains are regularly arranged using common vertices, thus forming spatial network structure - crystal clusters, by rotating the unit cell using the Diamond software and observing from different angles of the octahedron, it can be found that the basic structural unit of the octahedron is a distorted octahedron, and the four oxygen atoms on the red plane are not in the same plane, and it is this the distorted octahedron determines the structure of the anatase unit cell. At the same time, due to the stress in the molecule of the distorted octahedron, the unit cell density is lower than that of rutile, and the distance between the octahedra in the unit cell is relatively large, so the molecules can transform into a denser arrangement. Thus, anatase is a metastable structure with a transformation that tends to be stable.
The octahedron (TiO6) in the unit cell of rutile (Ti2O4) is connected by two common edges in the red plane. Several identical octahedra follow the principle of least steric hindrance and finally form a long chain with a linear structure. Chains and chains are regularly arranged at the expense of common vertices, forming a spatial network structure - crystal clusters. By rotating the unit cell using the Diamond software and observing the octahedron from different angles, it can be found that the basic structural unit of the octahedron is a regular octahedron. The four oxygen atoms are in the same plane, and it is this octahedral structure that determines the configuration of rutile. Compared to anatase, the octahedron in rutile has almost no stress, the molecular energy is low, and the molecules are close together, which is a stable structure.
Comparing the unit cell parameters of anatase and rutile, it is easy to see that the main difference between them is the number of atoms in the unit cell, the size of the unit cell, the volume of the unit cell, and the corresponding density. The density of rutile and anatase is determined by the unit cell. The calculated parameters are practically the same with the measured density. The primary reason for the difference in densities is the different shape of the octahedral units that make up the anatase and rutile lattices.
3. Hollow glass microspheres are only used as an auxiliary material in ZS-221 to block small colithe amount of solar heat absorbed by the coating.
Hollow glass microspheres are specially processed glass microspheres that are less dense and less thermally conductive than glass microspheres. It is a new lightweight micron-sized material developed in the 1950s and 1960s. Its main component is borosilicate, with an overall particle size of 10-250 µm and a wall thickness of 1-2 µm, hollow glass microspheres with the characteristics of high compressive strength, high melting point, high resistivity, small thermal conductivity and thermal contraction coefficient, it is known as " space age material" of the 21st century.
Fourth, carbon nanotubes
Carbon nanotubes, also known as tank tubes, are one-dimensional quantum materials with a special structure (radial size on the order of nanometers, axial size on the order of microns, and both ends of the tube are basically sealed. Carbon nanotubes are mainly composed of carbon atoms arranged in the form of hexagons, forming coaxial tubes with a number of layers from several to tens of layers.The fixed distance between the layers is about 0.34 nm, and the diameter is usually from 2 to 20 nm.to carbon Different orientation of the hexagon along the axis can be divided into three types: zigzag, chair and helix.Among them, helical carbon nanotubes have chirality, and zigzag and chair carbon nanotubes have no chirality.
As a one-dimensional nanomaterial, carbon nanotubes are lightweight, perfectly bonded into a hexagonal structure, and have many unusual mechanical, electrical, chemical, and optical properties.
Carbon nanotubes have a high photoelectric capacity to store energy and good photoelectron field emission. As a quasi-one-dimensional nanomaterial, it has a relatively large specific surface area and a unique hollow structure. When coated with ZS-221, excess photoelectrons that are not reflected from the surface are easily temporarily stored by it. Because the ports of carbon nanotubes are small and stable, when stored up to a certain amount, a tunnel chain propagation effect will form, and these photoelectrons will move towards the light-transmitting direction propagates.
5. Inorganic thermal barrier materials such as carbides and nitrides
MXene materials are a class of two-dimensional inorganic compounds composed of transition metal carbides, nitrides or carbonitrides several atomic layers thick. Its general chemical formula is Mn+1XnTX where (n = 1–3), M represents early transition metals such as Ti, Zr, V, Mo, etc., X represents C or N elements, and Tx represents is a surface group. , usually -OH, -O, -F and -Cl. At present, Ti4N3, Ti3C2Tx, etc. are widely used. This material has strong superconducting properties, provides more channels for the movement of ions, greatly improves the speed of movement of ions, and also has the properties of electromagnetic wave supershielding. After adding these materials to ZS-221, it is possible to form durable infrared shielding laminate. The electromagnetic waves emitted by these materials form a superimposed infrared shielding layer on the surface of the coating. When the infrared rays do not reach the thermal insulation coating, these infrared shielding layers. the amount of solar infrared rays, reducing the percentage of thermal infrared rays reaching the coverage.