Silicone oil is used as leveling agent in coatings.
Such as product model BD-3055 product name polyether silicone oil
Polyether modified organopolysiloxane with structural formula or component.
A widely used polyether modified silicone surfactant. Low surface tension, excellent compatibility with all film forming systems. It can be miscible with oily system or dispersed in water. It can be used in plastic processing, coating, ink, textile printing and dyeing, cosmetics and other industries.
Physical and chemical data and indicators
Appearance: transparent amber oily liquid
Specific gravity (25℃)1.05 0.05g/ml.
Viscosity (25℃) 1000 200℃.
Should be used
1, agricultural film defogging agent. 0.2~0.3% by weight of plastic film particles are added to the total formula (or mixed after being made into master batch in advance), and the film is blown to obtain the shed film with defogging function.
2. Adding PU leather coating system can improve leveling, anti-sticking and hand feeling.
3. Above the cloud point, it has excellent defoaming performance. Suitable for defoaming in the process of cleaning and spraying high alkalinity metals above 60℃.
Attached:
Synthesis and application evaluation of series silicone coating leveling agent
A series of polyether modified polysiloxanes were synthesized and their surface control properties were tested. Compared with three imported samples with the same concentration (based on the original solution), the comprehensive effect is better than that of imported similar additives, especially the slip and leveling effect of the coating.
Keywords: leveling agent, increasing slip
1, Introduction
With the development of China's economy, China's furniture exports occupy an important position in world trade. Accordingly, with the rapid development of high-grade wood coatings, various strong polar polymer resins and solvents with high surface tension are used more and more widely. With the development of high-quality, high-performance wood coatings, people pay more and more attention to smooth leveling agent with less addition and good effect. Among them, modified silicone oil is a kind of leveling agent widely used in coating industry, which has good leveling effect. It can reduce the surface tension of coatings, reduce the gradient of surface tension of coatings, prevent the formation of bainite spiral, improve leveling and gloss, reduce the interfacial tension between coatings and substrates, improve the wettability of substrates, and reduce coating surface diseases such as shrinkage cavity.
A considerable number of domestic additive enterprises are mainly agents and lack product development capabilities. In recent years, BYK, EFKA and TEGO have flooded into China, which has had a great impact on the domestic additive industry. At present, leveling agent imported from silicone has been widely used in high-grade coatings such as automobile paint and furniture paint, occupying most of the market share.
Zhejiang Xin 'an Chemical Group Co., Ltd. is a single manufacturer in silicone, second only to Bluestar Spark in China. As a national key high-tech enterprise, Xin 'an has a national technology center and more than 40 patented technologies with independent intellectual property rights, and more than 20 scientific and technological achievements have won national and provincial awards. On the basis of the upstream raw material of silica gel itself, the downstream industrial chain of Xin 'an has also infiltrated a series of products such as hot vulcanized silicone rubber, condensed room temperature vulcanized rubber, liquid addition rubber, modified silicone oil and so on. , thus forming a perfect industrial chain from upstream monomer to downstream products. In view of the lack of new product development and import substitution production capacity in domestic additives industry, Xin 'an has gradually formed silicone additives series with independent property rights through R&D production and market application evaluation since 2007, occupying a corner in the middle and high-grade additives market. In the product series, there are not only leveling agent with high smoothness and shrinkage resistance, but also low foam stabilizer with good handle and substrate wettability, and leveling additive with excellent substrate wettability and shrinkage resistance, which is suitable for water-based wood paint.
2. Synthesis of silicone leveling agent series.
2. 1 main raw materials
MM: self-produced, > 99%; DMC: self-produced, > 99.8%; Special hydrogen-containing silicone oil: self-produced, > 98%; Allyl polyether: made in China.
2.2 Synthesis process
Equilibrium reaction: adding MM, DMC and hydrogen-containing silicone oil into the reaction kettle in proportion, adding catalyst while stirring, reacting at room temperature for more than 6 hours, neutralizing and filtering to obtain polymerized hydrogen-containing silicone oil.
Addition reaction: the hydrogen-containing silicone oil and allyl polyether prepared above are respectively added in a proper proportion, stirred and heated, and the catalyst is added. When the reaction system becomes uniform and transparent, keep the temperature for 65438 0-2 hours, and then cool and discharge.
3, coating flatness and leveling performance test
Silicone leveling agent is mainly a variety of modified silicone oil with different structures. A series of leveling agent with different properties can be obtained through structural changes. By studying the relationship between the structure and properties of foreign serialized additives, we have a clear understanding of the factors affecting the surface properties of coating inks. Through comprehensive evaluation of the influence of various structural parameters, a series of surface leveling additives suitable for oily, waterborne and UV systems were obtained, so that surface control additives with different structures can be basically prepared for different systems. This lays a solid foundation for actively designing product structure according to customer's performance requirements and system requirements. According to the three characteristics of hand feeling, leveling and wettability, products with different emphasis are developed for use, and all of them have achieved satisfactory results.
The performance of silicone leveling agent mainly focuses on the following aspects: leveling, compatibility (transparency of reaction in varnish), smoothness of coating film, low foam stability, adhesion resistance, wettability of substrate and shrinkage resistance. The following table lists the performance summaries of several representative products. When selecting leveling agent, leveling agent should be selected according to the formula requirements to achieve the best performance and avoid side effects, so as to achieve balance.
Table 1 Summary of Comprehensive Performance of silicone leveling agent
Remarks on leveling, compatibility, smoothness, low foam stability, shrinkage resistance and anti-adhesion substrate wettability
XHG-230 repainted.
XHG-230P
XHG-2333 repainting.
XHG-237 repainted.
XHG-24 10 can be repainted.
XHG-2432
XHG-2450 repainted.
*XHG-245
*XHG-270
It should be pointed out that additives with excellent substrate wettability have great potential application value in the field of coating additives, and are on the rise. With the increasing pressure of environmental protection, waterborne wood coatings have developed rapidly, and waterborne leveling AIDS with high wettability and foam instability have great application value.