Water-based building coatings of the film-aid alcohol ester-12

Water-based building coatings of the film-aid alcohol esters - 12
Chen Weiming (China Association of Architectural Decoration materials Suzhou 215006)
Luo Qinghua (Xinhua latex coating film-aided film agent development center Honghu 433200)In the water-based building coating with synthetic resin emulsion as the main film-forming substance, film-forming agent is an indispensable and important additive. The choice of safe and efficient film-forming agent is an effective measure to control the content of toxic substances and the total amount of organic matter emission (TVOC) and ensure the healthy development of water-based building coatings. The basis of the selection of film-forming agents for water-based building coatings should embody the basic spirit of the Technical Requirements of Environmental Marking Products (HJBZ004-94), with the main focus: (1) having high technical performance and stable quality; (2) The control of formaldehyde, halides and aromatic hydrocarbons also considers the impact on TVOC; (3) Have a large market share and stable and reliable supply capacity. China's water-based architectural coatings (also known as latex paint) after nearly 20 years of development, has a considerable scale and foundation, but on the whole is not satisfactory, especially the product technology level and grade and foreign comparison there is a large gap. For example, polyethylene alcohol and polyvinyl acetate emulsion as the main film-forming substances of 106,803 low-grade coatings accounted for up to 70% to 75% of the total amount of paint, the film-forming agents used are mainly more toxic ethylene glycol monoethyl ether (ECS), ethylene glycol monotyl (BCS), diglycol and aromatics additives benzoyl alcohol, etc. The above additives not only have poor performance, but also use a large amount, high cost, to a certain extent, affect the development of water-based building coatings.In the mid-80's, China's new building materials company from the United Carbide Corporation, Japan's high-pressure gas and Suzy Deer Coatings Co., Ltd. segment optimization of the introduction of the international advanced level of Suzhou new architectural coatings factory tons of acrylic new building coatings project, not only the introduction of advanced water-based building coating manufacturing technology and production equipment, but also with raw materials imported the Japanese suffocator co., Ltd. high-quality film-forming agent CS-12. In the early 1990s, Eastman introduced the efficient and safe Texano lester alcohol, which has a large Chinese market share. In order to realize the localization of imported raw materials, the Ministry of Chemical Industry Jihua company carried out the corresponding research and development, in just a few years to complete scientific research and development and built a production base of 5000 t/a scale in Hubei. The addition of international advanced technology products, improve the overall technical level of water-based building coatings products and related supporting raw materials industry scientific and technological progress, so that China's water-based building coatings development has made a qualitative leap.Texano l ester alcohol is a commercial brand number of Eastman, the chemical name should be 2, 2, 4-methane-1, 3-glycol monoodes. CS-12 is the commodity name of Japan's Serotonin Co., Ltd., while Jihua's product name is alcohol-12, also known as 12 carbon alcohol esters (hereinafter referred to as alcohol ester-12), is suitable for water-based building coatings used in the typical film-forming agent (see Table 1). The so-called film-forming agent is in the water-based building coating in the appropriate amount of added, can reduce the glass temperature of the emulsion (Tg), soften the emulsion of the ommer and its co-cluster particle surface hardness, thereby reducing the minimum film-forming temperature (M FFT), in order to better coagulate the film, to be coated after the formation of the film-forming film agent gradually volatile, restore the initial Tg. Therefore, film-forming agents can also be called temporary plasticizers. Compared with other film-forming agents, alcohol esters-12 have typical characteristics suitable for water-based architectural coatings.(1) has a wide range of applications. Can be widely used in ethylene acetate and its co-polylactic emulsion, acrylic polypulfurizer and its co-polylactic emulsion, ethylene acetate/acrylic co-polylactic emulsion, styrene (SM)/acrylic co-polylactic emulsion, ethylene acetate/uncle carbonate Ethylene polyester emulsion, styrene/acrylates/methyl acrylates (MMA)/methyl acrylic shrinkage glycerides (GMA) multi-polyphur emulsions and other coating systems, can also be used as a film-forming agent for water-based inks.
(2) film-forming properties are good. The appropriate amount of addition helps the emulsion ommer and its co-ommer particles condense into a transparent, soft and complete latex film, thus improving the overall properties of the coating, such as adhesion, flatness, brightness, color spread, weather resistance, wash resistance and critical pigment volume concentration (CPVC).
(3) security is good. Alcohol-12 itself is non-toxic, contains very little residue of the harmful ingredient isodehyde, so the safety during use and storage is obvious, even long-term exposure to human health has no adverse effects (see Table 2).-12 also has excellent water insoluble, hydrolytic stability, lower volatility and solidification point than water, so it can better fully contact with polymer particles, helping to dissolve particles to form a better quality continuous film. Its higher film-forming effect can significantly reduce dosage, reduce costs and VOC compared with water-soluble film-forming agents such as glycol ethers. The lower solidification point allows the end product to maintain good freeze-thaw storage stability and construction under harsh conditions (e.g. high humidity, low temperature) at low temperatures (see Table 3).in general, the addition of alcohol-12 is approximately 10% of the total solid content of the required lotion, and should be adjusted according to Tg and temperature. As measured by reference to the typical ratio of coatings, the average addition of interior wall coatings is about 0. 6%, up to 1% < additions; The average addition of exterior paint is about 2. 2%, up to < 3. 4%。 Estimated by maximum addition, the residual amount of isodehyde solution in the interior wall coating should be < 0. 0015‰; The residual amount of isodehyde solution in the exterior < 0. 0035‰。 Alcohol ester-12 due to the significant improvement in film-forming performance, reducing the amount of use, not only to save raw material costs, but also to reduce VOC. Also estimated at the highest amount of addition, the VOC resulting from the interior wall coating should be < 10 g/L and the VOC of the outer wall coating should < 34 g/L. The above two environmental safety indicators are lower than the relevant standards, so the choice of alcohol esters-12 as China's water-based building coatings, whether from the technical performance, or environmental safety comparison is desirable.
China's production of alcohol esters-12 has reached a certain scale, quality has also greatly improved, especially Jihua Group (Hubei) Xinhua Chemical Company's alcohol esters-12 XH6 series of products production scale has been in the domestic leading position, its main technical indicators and total aldehyde residue has been close to the United States Eastman company's Texano lsterol. Can basically meet the development needs of China's water-based architectural coatings.