Bai junqian
(Tianjin Changlu Hangu salt farm Co., Ltd., Tianjin 300480)
Abstract: This paper briefly discusses the production process, production application and market prospect of Chloroether resin at home and abroad; It is proposed that the domestic technology is not very mature, which temporarily affects its large-scale development. However, with the continuous research and development of Chloroether resin, it will be gradually recognized and accepted by downstream coating manufacturers. It has broad market prospects in the coating market, especially in the anti-corrosion coating market, which is worthy of vigorous development of PVC enterprises.
Keywords: Chloroether resin; Copolymerization; Vinyl isobutyl ether; anticorrosive
doi:10.3969/j.issn.1008-1267.2011.05.002
CLC No.: tq326.52 document code: a Article No.: 1008-1267 (2011) 05-0005-03
Chloroether resin (fully known as vinyl chloride vinyl isobutyl ether copolymer resin, abbreviated as vc-ibve) is a kind of PVC copolymer widely used in coating industry and ink industry. It basically overcomes the shortcomings of other chlorinated polymer resins. It has the properties of chemical corrosion resistance, water resistance, weather resistance and good adhesion with metal matrix. It is an important marine paint It is one of the base materials of heavy-duty anti-corrosion coating and advanced ink binder. In Europe, Chloroether resin is widely used in container paint, marine paint, heavy-duty anti-corrosion coating and high-grade ink. At present, it has been widely used in the ink industry in China, while its application in coatings needs to be further developed.
As an anti-corrosion coating, the anti-corrosion ability of Chloroether resin is 2 ~ 3 times that of ordinary coatings. It is also a new resin to replace chlorinated rubber. Compared with chlorinated rubber, its coating has slightly better flexibility, heat resistance, UV stability, alkali resistance and pulverization resistance, and has a good market prospect.
1 resin properties
Chloroether resin is a copolymer of 75% vinyl chloride and 25% isobutyl vinyl ether. It is a white powder with a particle size of 0.4 ~ 1.69 μ m。 Its structural formula is as follows:
Due to the existence of flexible isobutyl side groups in Chloroether resin, its molecules are softer than PVC molecular bonds and have better internal plasticization. Plasticizers do not need to be added during use, which avoids the loss of mechanical properties due to the migration loss of external plasticizers, and it is not easy to be degraded by atmospheric oxidation because it does not contain reactive double bonds. Due to the long fat chain on the molecular chain, the resin has good solubility. It is very soluble with other coating base materials, and can improve and improve the coating performance with dry oil, alkyd resin, tar and asphalt as raw materials. The resin has good miscibility. It can be compatible with vinyl chloride polymer, acrylic resin, maleic anhydride resin, amino resin, modified alkyd resin, etc.
Because of its good adhesion, it has excellent adhesion with a variety of metal substrates. In addition to steel, it also has strong adhesion on BOPP and mixed PE.
The chlorine ether resin is very stable in combination with chlorine atoms, so that the coating and ink have excellent water resistance and chemical corrosion resistance.
In addition, it has excellent wettability to pigments and can basically be mixed with various fillers. Because the resin contains chlorine, it also has certain flame retardancy. By adding other flame retardant pigments, fillers and fireproof agents, it can be made into fireproof coatings, which can be used in the field of building fire prevention.
2 Production process
At present, the production methods of Chloroether resin mainly include emulsion method and suspension method. The process flow is:
2.1 emulsion polymerization
Tang Zhihu, Xie Jianwu and other [1], using (NH4) 2S2O8/Na2SO3/CuSO4 as oxidant reduction initiator system and twelve alkyl sulfate (SDS) as emulsifier, synthesized Chloroether resin by batch emulsion polymerization. It is found that the kinetic behavior of emulsion copolymerization of Chloroether resin has many aspects similar to VC emulsion polymerization. For example, when the comonomer is fixed, the intrinsic viscosity and molecular weight of the polymer are mainly determined by the polymerization temperature. The emulsifier and initiator system concentration has little effect on the intrinsic viscosity, and the emulsifier concentration has little effect on the polymerization rate. It can be seen that VC/IBVE emulsion copolymerization and VC emulsion homopolymerization process is similar, the polymerization occurs mainly in the water phase or has formed the latex particle surface, the polymerization rate has little relationship with the number of latex particles.
When the mass fraction of IBVE in the feed monomer increased, the polymerization conversion and the intrinsic viscosity of the copolymer decreased significantly at the same polymerization time. When the conversion was less than 70%, the average composition of the copolymer changed little; The polymerization rate increases with the increase of polymerization temperature, but the intrinsic viscosity of the copolymer decreases; SDS concentration has little effect on polymerization rate and intrinsic viscosity of copolymer; With the increase of initiator concentration, the polymerization rate increases, and the intrinsic viscosity of the copolymer changes little [2].
2.2 suspension polymerization
Jiangyin Huitong Fine Chemical Co., Ltd. cooperated with the school of chemical engineering of Lanzhou University [3 ~ 6]. After several years of joint research, Chloroether resin was developed and produced by suspension polymerization with water as continuous phase. In the polymerization process, in addition to mixing and dispersing the monomer with appropriate mechanical stirring form and rotating speed, an appropriate amount of surfactant and dispersant are added in order to form a stable polymerization system and obtain ideal polymer particles.
The formula is composed of monomer, comonomer, water, oil soluble initiator, emulsifier, third monomer, etc. The specific raw materials are:
Monomer: vinyl chloride, the dosage is 65% ~ 98%.
Comonomer: vinyl isobutyl ether, the dosage is 2% ~ 35%.
The third monomer: Jiangyin Huitong added the third monomer, which is 0.03% ~ 5% of the total weight of the monomer, such as acrylic acid, maleic anhydride, etc. The effect may be to adjust the copolymerization composition between vinyl chloride and vinyl isobutyl ether.
Water: the amount of water used as a medium in polymerization is similar to the usual emulsion polymerization, about 1~5 times the total weight of the monomer. Oil soluble initiator: the difference between micro suspension polymerization and emulsion polymerization is that oil suspension initiator is used in micro suspension polymerization. Emulsion polymerization is water-soluble initiator. Under slow stirring, the floating oil layer will not polymerize without initiator. The monomer must contact with water to polymerize. The oil soluble initiator used in micro suspension polymerization will agglomerate under the slow stirring, and the floating oil layer will be caked. To obtain good emulsion, the monomer oil droplet must be dispersed evenly in the water phase (homogenization). That is to form uniform emulsion. The common initiators are organic peroxide initiators or azo initiators.
Emulsifier (surfactant): the emulsifier used in the micro suspension polymerization of vinyl chloride / vinyl isobutyl ether is the same as the emulsifier used in emulsion polymerization of vinyl chloride, such as alkyl sulfate and alkyl sulfonate of anionic groups, and non-ionic polyoxyethylene ether and fatty acid esters as well. The dosage is 0.01% ~ 8% of the total weight of monomer.
Dispersant: the dosage accounts for 0.05% ~ 5% of the total weight of monomer, which can be hydroxycellulose, such as hydroxypropyl cellulose, etc.
The polymerization temperature is 40 ~ 80 ℃. During polymerization, keep stirring, and the polymerization reaction time is about 3 ~ 10 h.
The process has the advantages of easy control of reaction conditions, high polymerization yield and good resin quality. After removing residual monomers, washing, dehydration and drying, the total yield of polymerization can reach more than 95%.
3 Production and Application
3.1 foreign situation
Vinyl chloride and vinyl isobutyl ether copolymers were first produced by emulsion polymerization in Germany BASF company. They have been in the history of decades, and still have a unique market and application area [10].
BASF company [10] in Germany mainly produces Chloroether resin for coating, with the brand of laroflex MP, which has been widely used in Europe. The copolymerization resins produced by BASF emulsion polymerization are divided into different brands according to their viscosity, corresponding to different application occasions.
At present, the production and research of Chloroether resin are mainly concentrated in Japan and Europe. The copolymerization method of Chloroether resin has shifted to suspension method, and many applications have been developed, especially in coatings. These research results are basically disclosed in the form of patents.
3.2 domestic situation
In recent years, several domestic enterprises have successfully developed Chloroether resin products and occupied a certain market.
3.2.1 Jiangyin Huitong Fine Chemical Co., Ltd
At present, it is the only manufacturer in China that adopts suspension production process. As the first high-tech private enterprise in China to develop and produce Chloroether resin, it mainly produces Chloroether resin and its intermediate vinyl isobutyl ether for ink and heavy-duty anti-corrosion coatings. Combined with the technical characteristics at home and abroad, it began to work with relevant scientific research institutions in 2000. After years of joint research, it began to officially produce Chloroether resin with excellent quality in 2003. It is completely independently developed and has a number of patented technologies (Patent No. zl02138359.6).
A production unit of Chloroether resin with an annual output of 2500 t will be built. The actual annual output is about 2000 t. The "Sanhui brand" Chloroether resin produced by it is divided into five specifications: MP15, mp25, mp35, mp45 and mp60 according to different viscosity, of which mp45 is a special resin for ink [4].
3.2.2 Xuzhou Donghong Chemical Co., Ltd
Xuzhou Dong Hong Chemical Co., Ltd. [7] combines the technical characteristics of chlorinated ether resin at home and abroad, concentrating on research and development, adopting more advanced and more reasonable technology, and integrating the advantages of emulsion polymerization and suspension polymerization. Through ASPEN PLUS's rigorous calculation and simulation, the formula and technology of the product are optimized, and the quality of the chlorinated ether resin is greatly improved.
In fact, the technical key to the production of Chloroether resin products is how to solve the problem of polymerization degree between VCM and IBVE, and ensure that the relative molecular weight distribution of the obtained polymer is more reasonable. Aiming at this core problem, Xuzhou Donghong Chemical Co., Ltd. learned from each other and adopted a special feeding method to improve the polymerization mechanism of VCM and IBVE and greatly improve the quality of Chloroether resin.
The Chloroether resin produced by Xuzhou Donghong Chemical Co., Ltd. is maxweii, with specifications of MP15, mp25, mp35, mp45 and mp60 and output of 2000 t / A. the internal quality is basically consistent with that of the Chloroether resin of multinational companies. Some customers at home and abroad have tested and applied their resins, which has also proved that they can completely replace the products of multinational companies and meet the needs of domestic anti-corrosion coatings.
3.2.3 Hangzhou Electrochemical Group Co., Ltd
Hangzhou Electrochemical Group Co., Ltd. is one of the earliest enterprises engaged in the production of Chloroether resin in China. The products mainly include Chloroether resin mp25 for anticorrosive coating production and mp45 for ink production. Chloroether resin mp25 is the best substitute of chlorinated rubber for heavy-duty anti-corrosion coating resin. At the end of 2009, the company will move to Linjiang Industrial Park as a whole and build the project of "annual output of 300000 t ionic membrane caustic soda, 200000 t polyvinyl chloride, 50000 T electronic chemicals, 40000 t Chloroether resin, 100000 t hydrogen peroxide and other series of fine chemicals" in two phases.
3.2.4 Jiangsu Liside Chemical Co., Ltd
Jiangsu Liside Chemical Co., Ltd. [8] is one of the manufacturers specializing in the production of Chloroether resin and vinyl isobutyl ether. Its products are widely used in coatings, inks and other industries. At present, the output of Chloroether resin is 1800 T / A. The emulsion process was used. The company's products include mp25, mp35, mp45 and Chloroether resin mp45 for ink.
In addition, Zhejiang Jinhua new materials Co., Ltd. also produces Chloroether resin and vinyl isobutyl ether [9].
4 Market prospect
At present, domestic heavy-duty anti-corrosion coatings are far from meeting the different requirements for anti-corrosion performance in different fields in terms of quantity, quality and performance. Chloroether resin can be used as the base material of air drying coatings and coatings of other physical drying methods. At present, only Germany, the United States and Japan produce in the world.
As a copolymer resin used to manufacture anti-corrosion coatings, Chloroether resin has excellent cost performance and environmental protection advantages. Today, when the production of chlorinated rubber is facing a great crisis, Chloroether resin, as a base material for heavy-duty anti-corrosion coatings instead of chlorinated rubber, will have broad prospects and market potential. Although the domestic technology is not very mature at present, which temporarily affects its large-scale development, with the continuous development of Chloroether resin, it is gradually recognized and accepted by downstream coating manufacturers. It is believed that there will be a broad market prospect in the future coating market, especially the anti-corrosion coating market, which is worthy of vigorous development by PVC enterprises [11,12].
5 Conclusion
Chloroether resin has superior cost performance and environmental protection advantages, but the scale of domestic production enterprises is small, and the output is 1000 ~ 2000 t / A, so it does not have industry advantages. In addition, since there are no relevant standards for Chloroether resin products in China, enterprises can only refer to the enterprise standards of large foreign companies. Domestic enterprises should formulate their own industry standards from reality, which is more conducive to the promotion of Chloroether resin industry and the expansion of product application fields.
Reference:
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[8] China resin network http://www.resin.cn/trade_ supply/offer_ detail_ 166800.html.
[9] coating industry network http://www.tlcy.ibicn.com/news/detail.asp?articleId=197328. 2010-10-26 .
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