The binder used in inororal silicate coatings and their curing process

1. Introduction to inorance silicate coatings
Inorance coatings have not been clearly defined, according to the habit of coating naming is generally classified as the main film-forming substances, so inorance coatings usually refer to inorance materials as the main film-forming substances or binders of a class of coatings.
common inorder binders are cement, gypsum, water glass, silicone sol, lime and so on. According to the chemical composition, inorganic binders are silicates, phosphates, oxides, sulfates and borates and other

. According to the curing method, can generally be divided into the following four categories.
(1) air dry type: solidified by the volatile or loss of moisture of the solvent, e.g. water glass, lime, etc.
(2) water curing type: water as a curing agent, water to produce chemical reactions and curing, such as gypsum, cement, etc.
(3) hot melt type: the inorgeous hot melt is first heated above the melting point, then bonded, cooled and cured, such as low melting point metal, low melting point glass, etc.
(4) chemical reaction type: by adding curing agents other than water to produce chemical reactions and curing, such as silicates, phosphates, colloidal alumina and so on.
inorderable binders used in building coatings are mainly lime and silicate. Under the role of carbon dioxide, lime-based binders are carbonized into carbonates, silicate binders are siliconized into silicates, and together they form calcium silicate hydrates. Lime-based inorganic coating weather resistance in general, silicate coatings generally use potassium glass as a binder, weather resistance is excellent, life span of more than 100 years is possible, Europe still has a well-preserved 100 years ago silicate coating buildings.
inorderable adhesives used in building coatings are alkali metal silicates and silicone sols. China's construction industry standard JG/T 26-2002 "exterior inorderable building coatings" according to the main types of binders are divided into two categories. Among them, class
I. : alkali metal silicates - potassium silicate, sodium silicate and other alkali metal silicate as the main binder, added pigments, fillers and additives preparation.
II. Class II: Silicone Sol - Silicone sol as the main binder to add the appropriate amount of synthetic resin emulsion, pigments, fillers and additives.
in the JG/T 26-2002 standard preparation of the domestic market before 2002 inororgable paint varieties of the internal wall, so did not consider the interior wall inoranced architectural coatings, the standard name as "external wall inorgable building coatings." In recent years, the domestic use of interior wall inorgic architectural coatings than external wall inorgic architectural coatings more common, so the revised JG/T 26 standard changed the name of the standard to "liquid inorgic coatings for the interior and exterior walls of the building", including the building exterior wall inorgic coatings and the building interior wall inorient coatings.
In accordance with the requirements of the German standard DIN 18363, the quality of organic ingredients in silicate latex coatings does not exceed 5% (W/W) of the total dry film quality, the test method is to 2 hours at 200 degrees C after drying the quality of the coating as the quality of the total dry film, this dry film at 450 degrees C after 2 hours of burning, burning weight as the quality of organic ingredients. Drying for 2 hours at 200 degrees C is to ensure that crystalline water in the coating is completely evaporated, and burning at 450 degrees C for 2 hours is to allow organic film-forming substances and organic additives to burn completely, while ensuring that inorganic fillers such as calcium carbonate do not break down. German standards further guarantee the properties of inorganic coatings by strictly limiting the amount of organic resins used to ensure that inorganic coatings are the primary binders of inorganic materials.
China's construction industry standard JG/T 26-2002 "external wall inorger building coatings" will be inoranced coatings according to the main types of binders divided into I. class - alkali metal silicate and II. class - silicone sol class is debatable, although different particle size and surface characteristics Silicone adhesive bonding capacity is different, but overall silicone adhesive bonding capacity is poor, it is difficult as the main adhesive to meet the internal and external wall building coating physical and chemical performance requirements, even pure silicone sol after complete curing is also difficult to form a film, easy to powder, add a large number of pigments, fillers after the paint film performance is even worse. Generally speaking, silicone sol can only be used as a secondary binder, with other inorganic or organic major binders such as alkali metal silicate, synthetic resin emulsion, etc. to meet the requirements of the building interior and exterior wall coatings for chemical and chemical properties. If silicone sol and emulsion together as a composite binder, the emulsion must be the main binder, when the performance of the coating film is closer to the performance of latex paint, it is difficult to meet the DIN 18363 standard limit requirements for organic ingredients. Pure inorganic coatings can only be completely alkali metal silicate as a binder, or alkali metal silicate as the main binder, silicone sol as a secondary binder, it is difficult to use silicone sol as a binder.
from Europe, where inorganic coatings are most developed, inorganic coatings have been from the first generation of pure silicate coatings to the second generation of silicate emulsions since 1962 (Silicate Emulsion Coatings or Organo-siliate Coatings), and the third generation of silicone inorganics (Sollicate inorganic coatings) since 2002 -Silicate Coatings) is based on silicate as the main binder, even if the third generation of inorgeable coatings use silicone sol, but the main binder is still alkali metal silicate, silicone sol only as a secondary binder to change silicate, using the weak characteristics of silicone adhesion to reduce the coating curing contraction stress, to apply to more substrate coating.2. History of inorganic coatings
About 6,000 years ago, ancient Egyptians used quartz sand and natural soda or potassium carbonate produced by combustion processes to produce sodium silicate or potassium silicate. It is widely believed that the chemical composition of the frescoes preserved after the eruption of Mount Vesuvius in 79 B and the ruins of the ancient city of Herculaneum is alkali metal silicate. In the 16th century, alchemistes in their quest for "philosopher's stone" discovered that sand and potassium carbonate fused in fireplaces to create sparkling water glass.
although there have been numerous references to water-soluble silicates, the real start of practical applications took place in 1825, under the auspices of Fox, a professor of mineralogy in Munich, Germany. He did a lot of pioneering work and systematically studied what he called water-soluble sodium silicate and potassium silicate production methods. At the same time, it is proposed that water glass can be used as a binder, cement and fire protection coating, can also be used to seal porous stone and as a base for mural coating. In 1855, water glass began commercial production in Europe and the United States.
King Luvich I of Bavaria was impressed by the colourful lime frescoes of northern Italy and was eager to experience them in his bavarian kingdom, but the weather in the northern Alps was so bad that they were destroyed in a very short time. So he issued an order to the Bavarian Academy of Sciences to develop a coating that looked like a lime fresco but was more durable. Scientist Adolf William Kem, using water glass as a binder to try to make silicate coatings, finally achieved good results after several years of experiments, in 1878 applied for the first inororate silicate coating patent, and began the production of silicate coatings. To this day, KEIM FARBE Coatings(known in China as Mine Coatings) is named after him, and KEIM FARBE Coatings is one of the world's leading manufacturers of inororated silicate coatings.
The first generation of inorganic coatings invented by Kem more than 140 years ago was pure inorganic silicate paints, a two-part coating (also known as a 2K coating) consisting of powders made up of inorganic pigments, fillers, and potassium silicate. In accordance with the requirements of the German standard DIN 18363, 2.4.1 silicate coating, the formula is two components, completely free of organic composition, can only be used for the application of strong, absorbent mineral substrate surface. Since the 1870s, the first generation of inorgeable coatings has been used in Europe in architectural coatings, its excellent weather resistance and color fastness is still unridable. Buildings decorated with inorgic silicate paint in the 19th century are still well preserved, such as the White Eagle Inn in Stein on the Rhine in Switzerland and the town hall in Schweitz, as well as the facades of Oslo and Trenstein in Germany. The first generation of inorgeable coatings is still in use, but its disadvantage is two-part packaging, must be fully mixed before use, and requires a certain amount of time to mature.
has a long-term experience of 2K inorganic silicate coating super weather resistance, but also see the emerging organic latex coating easy to produce, storage stability excellent, easy to build attraction, the market has combined the advantages of the two single-component packaging of inorganic organic composite building coating desire, in 1962 the second generation of inorganic silicate coating came out, it is Potassium silicate as the main binder, supplemented by a small amount of high alkali-resistant organic synthetic emulsion, and added the appropriate amount of inorganic pigment, fillers and additives composed of a single component of silicate emulsion coating (Silicate Emulsion Paints), also known as organo-silicate paints. According to german standard DIN 18363, 2.4.1 for latex coatings of silicate, the organic ingredients (including emulsions and additives) do not exceed 5%. Due to the emergence of the second generation of inorgeable coatings, since the 1970s, inorgeable coatings in the form of silicate latex coatings by consumers, has been vigorously developed around the world, especially in Europe.
The emergence of third-generation inorgeable coatings revolutionized the exterior coatings market in 2002: Sol-silicate Paints, based on the new adhesive concept, opened up new applications for inorgeable coatings. This new substrate is a stable mixture of silicone sol and potassium glass that, in addition to collaborating with chemical bonds produced by siliconization and inorganic mineral substrates, also produces strong adhesion to solid organic coatings, making it available on almost any ordinary substrate surface. The organic content of silicone silicate coatings is still controlled at less than 5%, thus meeting the requirements of DIN 18363 for latex silicate paints.
from the first generation to the third generation of inorgeline coatings, the development of three important milestones have been widely recognized by the world paint industry. With the development of inorcleable coating technology, new varieties continue to emerge, the German Mineral Brand Coatings (KEIM FARBE) in 2013 released the fourth generation of inorgeable coatings for wood surfaces, and in 2018 an inorgeable coatings company in Kuala Lumpur, Malaysia, also launched their fourth generation of inorgeable coatings - can be used for tropical ocean rainy climate of the outer wall silicate hybrid inorgeable coatings.
inoritable silicate coatings have grown to account for 10-15% of the water-based architectural coatings market in Europe today, as well as in the United States, Asia and Oceania. Since the early 1980s, China has also had inorganic coating research reports, the domestic development of several kinds of sodium silicate, potassium silicate and other inorganic coatings for film. However, China's real engineering to get a large number of applications are mainly silicone sol modified synthetic resin emulsion exterior coating and potassium silicate as the main film-forming substances of the two-component outer wall coating. In addition to ordinary decorative function-based exterior paint, functional wall inorgeted paint has also been very good application and development, its main varieties of inorgeable mold-proof paint, inorge inorge insulation paint, inorgeable anti-dew coating and inorder fire-resistant paint. Although the advantages of inorance coatings in China have been widely recognized, but architectural coatings are still synthetic resin emulsion coatings as the absolute leading products, inorance silicate coatings research and application is still less, with the developed countries in Europe and the United States is still a big gap. In recent years, the domestic construction industry market due to the national underground closed space fire prevention, non-combustible interior wall paint mandatory requirements and home improvement market demand for low VOC, low preservatives environmental protection interior wall coatings, promote the development of inorance interior wall coatings, the major domestic building coating manufacturers are in the research and development of inorance building coatings, and constantly introduce their own new products, so that inorgeable silicate coatings in China to find a rare development opportunity, and thus created a number of inoromic paint professional production enterprises. It is believed that inororated silicate architectural coatings will become another hot spot in China's architectural coatings market after real stone paint and water-based colorful coatings. 3. Water-soluble silicate chemistry and inorderable coating curing mechanism
3.1 Water-soluble silicate production and manufacturing
In nature, more than 95% of the earth's crust is composed of quartz and a variety of rock-forming silicates. These include 42% (volume content, same between 2nd) oblique stones: Na (AlSi3O8) - Ca (Al2Si2O8), 22% potassium longstone KAlSi3O8, 18% quartz (silica dioxide), and other more complex silicates including 5% horned stone and 12% other silicates. In addition, large amounts of silicate have been found in alien interstellar matter. So we can think of silicate materials as very close to nature, but as silicates that can be used in coatings and chemical building materials, we must focus on water-soluble silicates, especially water-based alkali metal silicates. The alkali metal element in the
-element periodic table is the first family of elements located on the far left, including lithium (Li), sodium (Na), potassium (K), (Rb), cesium (Cs), (Fr), and we will only discuss lithium, sodium, and potassium, the first three alkali metal elements that have commercial significance for inorganic coatings. If you continue to study the elements of the second main family, you will find that the insoluble silicates formed by the alkaline soil metals of the second main family can be used in the author's glass, and their silicates are also the main components of cement, and these alkaline metal ions, once in contact with soluble silicates, form the insoluble silicate inorgable coating we want.
alkali metal silicate is an inorganic silicate material often used as a binder in the coating industry, it is a synthetic material, by quartz and alkali metal lithium, sodium, potassium carbonate melting reaction in a glass furnace at a high temperature of 1300 degrees C, The reaction and manufacturing process is as follows:
molten alkaline metal water glass flows from the furnace to the cooling conveyor belt and into the solubility tank, soluble silicate dissolves in hot water at high pressure, insoluble glass and unresponsive quartz sand can be removed by filtration. The resulting soluble alkali metal silicate does not have a clear chemical measurement composition and depends entirely on the ratio of raw materials in the above reactions. Water-soluble alkaline metal silicates can form transparent solutions or translucent colloidal solutions in water, and in addition to the lowest concentrations, their solutions exhibit viscosity properties of non-Newtonian fluids.
industrial base metal silicate solution