paint asphalt
There are three main types of paint asphalt: natural asphalt, petroleum asphalt and coal tar asphalt.
Natural bitumen is extracted from bitumen mines.
Petroleum asphalt is processed by the residual by-products of gasoline, kerosene, diesel oil and lubricating oil in crude oil after fractionation and separation. Its basic components are asphaltenes, saturated hydrocarbons, aromatic hydrocarbons, resins and waxes. Petroleum asphalt is mainly used as anti-corrosion material in the petroleum industry, such as anti-corrosion of buried pipelines. Multiple layers of thick coatings are used, with fiber material woven between the layers.
Coal tar pitch is the residue of light oil, phenol oil, naphthalene oil, etc. extracted from coal tar, and is a by-product of coal coke and gas. Coal tar is also called coal tar, so some foreign paint suppliers translate epoxy coal tar paint into tar epoxy.
Coal tar pitch has very low water absorption compared to natural and petroleum pitch. Therefore, coal tar pitch is more important in anti-corrosion coatings and has excellent corrosion resistance.
Water resistance of petroleum asphalt and coal tar pitch. Coal tar pitch is an aromatic pitch, the ratio of carbon atoms to hydrogen atoms exceeds 1.4:1, while the ratio of carbon atoms to hydrogen atoms in petroleum pitch is about 0.9:1, so coal tar pitch has better water resistance.
Coal tar pitch paint film has excellent water resistance, good wettability to the steel surface that has not been completely derusted, low price, and thicker paste paint can be obtained. Coal tar pitch becomes brittle in winter and softens in summer. When exposed, the tar will escape, cracking the paint film. Add coal powder and plasticizing oil, and digest at 300°C to remove low-boiling fractions and acidic oils, thereby increasing its softening point and penetration.
The coating types of coal tar pitch mainly include the following types.
(1) Asphalt paint A solution of pure asphalt in a solvent, such as a container primer.
(2) Asphalt antirust paint can be made into antirust paint with good seawater resistance by adding aluminum powder, iron oxide red and other antirust pigments. It has been widely used on the bottom of ships.
(3) Coal tar pitch green enamel paint is made by adding coal powder, coal tar and mineral fillers to coal tar pitch and heating. Since the 1980s, it has been widely used in the anticorrosion of the outer wall of oil and gas pipelines.
Coal tar pitch can be mixed with chlorinated rubber, polyurethane, epoxy and other coatings. Among them, the epoxy coal tar pitch paint is the most successful, combining the advantages of both pitch paint and epoxy resin paint.
Although asphalt paint is a paint with a long history, it is harmful to human health and should be phased out of use. Because asphalt contains photosensitive substances such as anthracene, phenanthrene, pyridine, pyridine, and carpyridine and noise, photosensitive dermatitis will occur on parts of the body that are exposed to asphalt in the sun. Contact with asphalt fumes can cause rhinitis, laryngitis and bronchitis. The clinical manifestations are that after contact with asphalt dust and smoke, especially under sunlight, large erythema, itching, and burning sensations will appear on the exposed parts such as the face, neck, hands, and limbs. In severe cases, local edema, blisters and exudates may appear. Systemic symptoms may include headache, dizziness, fatigue, arthralgia, nausea, vomiting, abdominal pain, and diarrhea. Accompanied by fever and leukocytosis.
Because bitumen is a carcinogen, its use in paint is restricted in Europe and the United States. Ship ballast tanks, once the main application area for epoxy coal tar pitch, have now been completely banned and light colored modified epoxy coatings are used.
Asphalt Hot Melt Adhesive Viscometer
It mainly measures substances that are solid at room temperature and become liquid after heating at high temperature, such as asphalt, hot melt adhesive, polyethylene wax, etc.
It can be used as a stand-alone machine, and the measurement data can be directly displayed on the LCD screen without secondary calculations; it can also be equipped with "data collection analysis and drawing software" to realize data collection and data analysis, and monitor the viscosity-temperature curve throughout the process.
Using high-resolution stepping motor, the speed is accurate and stable.
LCD liquid crystal with blue backlight function, directly display viscosity, speed, percent torque, rotor number, and the maximum viscosity value and temperature value that can be measured at the current speed of the selected rotor. DV-2 series can also display shear rate and shear stress. The viscosity value shows a continuous change, and there will be an alarm sound when it exceeds the measurement range.
The measurement performance of the instrument has reached the level of foreign products of the same type through computer correction.
The high-temperature furnace adopts built-in overall heating, which is evenly heated and has small thermal inertia.
