Jiang Juan Cheng, Hai Ling, Zhu Jie
(1) Shengli Oilfield Lifeng industry and Trade Co., Ltd., Shandong Dongying 257508;
2. Drilling engineering technology company of Shengli Petroleum Administration Bureau, Shandong Dongying 257064)
Abstract: the advantages, anti-corrosion mechanism, research status at home and abroad and its application in coatings of Chloroether resin were introduced. The application prospect of Chloroether resin was prospected.
Keywords: Chloroether resin; Coatings; application
Chinese Library Classification No.: TQ 630.7 document identification code: a Article No.: 1009-1696 (2010) 08-0053-03
Introduction
Chlorinated polymers are widely used because of their excellent corrosion resistance. Chlorinated rubber occupies a large proportion in chlorinated polymers because of its excellent corrosion resistance. In recent years, the requirements of environmental protection regulations are becoming more and more strict. Traditional chlorinated rubber is limited by countries because it contains more residual CCH and pollutes the atmosphere. According to the provisions of the Montreal Protocol, developed countries have successively shut down the production of chlorinated rubber with carbon tetrachloride since 1995, allowing a 10-year grace period for developing countries, that is, to stop using carbon tetrachloride by 2005. As a base material for heavy-duty anti-corrosion coatings instead of chlorinated rubber, Chloroether resin has a very broad application prospect because of its superior price and environmental protection advantages.
1 Advantages of Chloroether resin
Chloroether resin has the following advantages:
(1) Good anti-corrosion performance: the Chloroether resin molecule does not contain saponifiable ester bond, and has good acid resistance, alkali resistance and salt resistance. It has wide miscibility with other resins for coating, which can improve the performance of other resins (such as alkyd resin, asphalt, etc.). For example, alkyd resin coating needs air oxidation to form a film, and the drying speed is slow. After adding Chloroether resin, it can accelerate its drying speed, reduce peeling, especially prolong its service life in the atmosphere, and significantly improve its chemical resistance and steam resistance.
(2) Strong stability: there is no reactive double bond in the molecule of Chloroether resin, which is not easy to be degraded by atmospheric oxidation; Excellent light stability, not easy to yellowing and pulverization.
(3) Good adhesion: there is ether bond in the Chloroether resin molecule, which makes it have good internal plasticization and sufficient flexibility without adding plasticizer. In this way, the content of plasticizer in the formula can be controlled very low, and the hardness of the film will not be reduced due to excessive plasticizer, resulting in orange peel, cracking, pinhole and contamination. Chloroether resin contains copolymerized vinyl isobutyl ether, which is easy to form hydrogen bond with the substrate to ensure good adhesion of the coating on various substrates.
(4) Strong solubility: Chloroether resin and other coating base materials
It is very soluble and can improve the performance of coatings such as dry oil, alkyd resin, tar and asphalt. Chloroether resin does not contain reactive groups and can basically be mixed with various pigments and fillers. Pigments and fillers and different pigment volume concentrations can be selected according to different needs.
(5) Fireproof: Chloroether resin contains chlorine and has certain flame retardancy. It can be made into fireproof coating by adding other flame retardant pigments, fillers and fireproof agents, which can be used in the field of building fire prevention.
2 Anticorrosion mechanism of Chloroether resin and its research status at home and abroad
2.1 anti corrosion mechanism
Chloroether resin is the abbreviation of vinyl chloride vinyl isobutyl ether resin, which is copolymerized by 75% vinyl chloride and 25% vinyl isobutyl ether. The appearance of Chloroether resin is white powder particles, and the particle size is generally 0.4 ~ 1.69 BTM. The isobutyl ether long chain structure in the Chloroether resin structure exists as a branch of the polymer chain, which makes it difficult for the polymer molecules to stack tightly, reduces the crystallinity, and macroscopically shows that the flexibility of the polymer is enhanced; There are a large number of ether bonds in the polymer chain, so that its rotation free energy is low and has excellent internal plasticization. The coating substrate has good adhesion. The coating also has sufficient flexibility without additional plasticizer, so the coating will not become brittle, crack and fall off due to the migration of plasticizer. It shows excellent adhesion in two and three paint systems, and also has excellent adhesion on the surface of metal aluminum and zinc; Chloroether resin does not contain reactive double bonds and is not easy to be degraded by atmospheric oxidation. The coating made of Chloroether resin has excellent atmospheric aging resistance and light stability, and is not easy to yellowing and pulverization; The copolymer does not contain saponifiable ester bond, and because the combined chlorine atom is very stable, the coating has excellent water resistance and chemical resistance. It does not contain reactive groups, can basically be mixed with various pigments and fillers, and has good wettability to pigments and fillers; Pigments, fillers and different pigment volume concentrations can be selected according to different needs. At the same time, Chloroether resin has good miscibility with other polymer materials.
2.2 research status at home and abroad
Since the early 1980s, the research on the preparation and application of Chloroether resin has basically focused on Japan and Europe. The copolymerization method of Chloroether resin has turned to suspension polymerization, and many applications have been developed, especially in coatings. These research results are basically disclosed in the form of patents. The research on Chloroether resin in China started late and less. The research on the modification of Chloroether resin and the application of modified Chloroether resin in coatings were carried out by Marine Chemical Research Institute and German BASF. Due to the relatively high price of Chloroether resin, the practical application of Chloroether resin coating has been stagnant. At present, Jiangyin Huitong Fine Chemical Co., Ltd. and the school of chemical engineering of Lanzhou University have completed the first set of Chloroether resin plant with an annual output of 2500 t in China after several years of joint research. With the localization of Chloroether resin, the price factor is gradually ignored. Therefore, the research on Chloroether resin coatings, especially anti-corrosion coatings, will have a broad space.
3 Application of Chloroether resin in coatings
Chloroether resin coating is non-toxic, has strong adhesion to various substrates, has excellent aging resistance and corrosion resistance, and its corrosion resistance is 2 ~ 3 times that of ordinary anti-corrosion coatings. It has a wide range of applications.
3.1 industrial anticorrosive coatings
Chloroether resin coating is not easy to aging, water resistance, chemical resistance, and good adhesion with a variety of substrates. It is suitable for the anti-corrosion of steel components in the chemical industry and can prevent the corrosion caused by the atmosphere. Chloroether resin can be prepared into primer with good performance with antirust pigments and fillers, and zinc rich primer with zinc powder to play a good anti-corrosion role. It can also be prepared into finish paint with mica iron oxide. It is widely used in steel components such as external pipelines and storage tanks in factories, as well as buildings in contact with water and steam.
3.2 paint for ships and containers
The anti-corrosion performance of Chloroether resin coating is 2 ~ 3 times that of ordinary anti-corrosion coating. It has excellent water resistance, salt water resistance, alkali resistance and salt fog resistance. Moreover, the prepared coating dries quickly and is easy to use. It is widely used in the fields of transportation, marine engineering and so on. From the 1960s to 1990s, the marine coatings based on chlorinated rubber coatings formed a series of supporting coating systems from above water to underwater and from hull to inner cabin, including more than a dozen varieties, which used to be the main body of medium-grade marine coatings. At present, Chloroether resin coating has gradually replaced chlorinated rubber coating for ship anti-corrosion protection, which can well meet the requirements of sunlight exposure and seawater erosion. The results show that only 5% of the steel plate is adhered by marine organisms after being soaked in seawater; After adding zinc oxide and phenylphenol, the coating has good stain resistance, and the coating is still not contaminated after soaking in seawater for two years. BASF of Germany, Nippon of Japan, Mitsubishi materials and other companies have carried out a large number of research work on Chloroether resin marine coatings. The coating prepared by mixing Chloroether resin and alkyl phosphate is used for degreasing steel plate. After drying at room temperature for 7 days and 40 for 1 day, the salt spray resistance of the coating reaches more than 500 H.
Container transportation has become one of the main modes of international transportation because of its high loading and unloading efficiency, convenient transportation and good safety. In order to ensure the quality of container coatings, the International Committee for container standardization has unified regulations on the identification and testing of container coatings, that is, the coating system must pass the 8 projects and 13 methods of konstandt lab in the United States, and obtain the Laboratory Approval Certificate (the total score exceeds 120) before it can be used in the container. Chloroether resin coating is used in the field of container because of its excellent adhesion and water resistance, and can ensure the stability of the coating within the range of large temperature change.
3.3 light metal primer and finish
Generally, the synthetic resin coating cannot adhere well to aluminum, zinc, galvanized steel plate and other non-ferrous metals, and the coating will peel off from the substrate. Chloroether resin coating is widely used in the coating of garage doors and windows, roof gutters, lamp columns and highway anti-collision isolation plates because of its strong adhesion and ideal outdoor performance.
3.4 plastic coating
Applying Chloroether resin coating on plastic substrate (such as polyester, rigid polyvinyl chloride, nylon, polystyrene, phenolic resin, etc.) can not only color the plastic, but also have yellowing resistance and powdering resistance. If it is mixed with acrylic resin, the effect is better.
3.5 inorganic substrate coating
It is reported that coatings containing Chloroether resin and corresponding alkali resistant plasticizer can be used for alkaline materials such as asbestos, cement, concrete, masonry and so on.
4 Conclusion
In the new century with increasingly strict environmental protection requirements, Chloroether resin, as the base material of anti-corrosion coating instead of chlorinated rubber by carbon tetrachloride solvent method, has a broad application prospect because of its superior price and environmental protection advantages. Compared with chlorinated rubber by carbon tetrachloride solvent method, Chloroether resin is not only non-toxic, but also has advantages in flexibility, heat resistance, UV stability, alkali resistance and powdering resistance of the coating. It can be miscible with alkyd resin, acrylic resin and epoxy resin, which can greatly improve the performance of the resin.
Reference
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3 Hou Baorong. Corrosion research and protection technology [M]. Beijing: Ocean Press, 1998:138-145
