• Silicone - acrylic resin modified waterborne polyurethane
    Silicone - acrylic resin modified waterborne polyurethane


    1.Introduction to silicone acrylic emulsion Silicon-acrylic emulsion is a kind of composite emulsion. It is a copolymer emulsion of organosilicone and acrylate.Acrylic resin has many excellent characteristics, such as weather resistance and light resistance, long time under ultraviolet irradiation is not easy to yellow。In addition, it also has flexibility, so it is often used as a leather finishing agent。However, as acrylic resin belongs to thermoplastic materials, it is a linear molecular structure, lack of crosslink points, not easy to form a network structure, sensitive to temperature changes, high temperature return viscosity, low temperature lack of elastic, that is, easy to appear hot viscosity cold brittle phenomenon. The main chain of organosilicon resin is si-o bond, and its bond energy is 450k J/mol, which is much higher than the bond energy of 345kJ/mol of c-c bond and bond energy of 351kJ/mol of c-o bond. Therefore, organosilicon resin has good resistance to high temperature, infrared radiation and ultraviolet light, chemical resistance;In addition, the surface energy of organosilicon resin and low vitrification temperature are low.With good hydrophobic wear resistance and anti - pollution. In summary, the modification of acrylic resin with an appropriate amount of silicone resin can not only make up for the defects of acrylate, but also improve its mechanical properties. 2.Modification method of silicon - acrylic emulsion Silicone acrylic emulsion modified method there are two ways: the physical method is to a certain amount of siloxane and acrylate mechanical mixing, this method is simple, but due to both the surface and the difference of molecular structure, poor compatibility with polysiloxane acrylate, because the former is migration, caused by composite emulsion stability is poor, prone to phase separation phenomenon, the result is not ideal.Chemical method is the use of emulsion polymerization, in addition to the siloxane and acrylate have a simple physical cross-linking, but also the existence of chemical bonds, so that the two components of the polarity of the material with a large difference in the combination, in the micro to achieve uniform dispersion, improve the stability of the emulsion. The silicon-propylene composite emulsion was prepared by chemical method, and then the silicon-propylene composite emulsion was used to replace the water-borne polyurethane emulsion.The modified waterborne polyurethane emulsion has the advantages of three, and the water resistance is improved. According to the preparation method of si-acrylic emulsion, si-acrylic emulsion was prepared by seed emulsion polymerization with methyl methacrylate acrylic vinyl silicone oil as raw material.Then the prepared silicon-acrylic emulsion was modified to the prepared waterborne polyurethane, the composite emulsion was configured by blending method, the film was formed on different substrates, and the mechanical properties of the film such as adhesion...

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  • Application of two - component waterborne polyurethane
    Application of two - component waterborne polyurethane


    At present, two-component waterborne polyurethane has been widely used in leather, textile dyeing AIDS, adhesives, foam materials, coatings and other fields. With the continuous development of two-component waterborne polyurethane scientific research, it is gradually replacing solvent polyurethane as the medium to occupy the dominant position in the market. One: leather China's leather resources, production and export trade are among the world's leading.China's annual consumption of polyurethane synthetic leather paste is nearly 2.4 million tons. The solvent polyurethane used in the synthetic leather industry has caused serious environmental pollution, and the production process of water-based synthetic leather cleaning emerged as The Times require.At present in the leather industry, waterborne polyurethane is mainly used for leather finishing, leather filling, leather adhesive and so on.In synthetic leather, the dispersed two-component waterborne polyurethane can be used as adhesive for artificial leather and surface treatment agent for artificial leather, as well as for synthetic leather bass, surface layer resin, bass veneer and special base coating resin. Two :Textile dyeing auxiliaries In the field of textile industry, two-component waterborne polyurethane can be used as dyeing AIDS, printing, finishing agents, etc., showing good application properties, such as flame retardant, breathable, wrinkle resistance, etc.Fabric finishing agent is a layer of coating on the surface of the fabric, on the one hand, the surface gives the fabric some functions, such as waterproof, fire, etc.On the other hand, different fabric finishing agents give fabrics different appearance styles.Traditional solvent - based two - component polyurethane system contains a large number of organic solvents, causing great harm to human body.The two-component waterborne polyurethane system is free from harmful solvents such as formic acid, which may be the development direction of textile dyeing auxilaries in the future. Three : Adhesive National standard GB/ t30779-2014 waterborne polyurethane adhesive for shoes was officially implemented.This standard has filled the gap in the field of waterborne polyurethane adhesive for shoes in China, further standardizing the market order of waterborne polyurethane adhesive for shoes, and has a good promoting effect on environmental protection and energy saving in the production of shoes.Two-component waterborne polyurethane adhesive is widely used in the fields of soles and uppers, leather, home building materials, automotive interior and so on, but there are serious safety, health and environmental protection problems in the production and application of solvent adhesive.With the promotion of national policies and the continuous enhancement of enterprise customers' concepts of safety, green and environmental protection, it has become a trend to vigorously research and develop environmentally friendly adhesives with high technical con...

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  • Common problems and solutions in the construction of polyurethane waterproof coating
    Common problems and solutions in the construction of polyurethane waterproof coating


    In polyurethane waterproof coating construction often encounter some problems, so in the process of waterproof construction encountered different problems how to solve it?Sinograce waterproof with you to learn the following, polyurethane waterproof coating construction common problems and solutions. 1. viscosity (1) coating itself viscosity is very large, construction effort. (2) if the client applies roller coating and brush coating, less viscosity is needed to facilitate construction. Solution: it is recommended to use rubber or metal scraper scraping coating construction, not to use roller coating or brush coating construction.Add diluent, should do small test first. 2.A large number of bubbles or holes appear in the film Under the following conditions, the coating is prone to a large number of bubbles or holes: (1) wet or rainy weather.Do not be in wet or rainy day construction, after the rain to wait for the base dry construction, after the construction to do rain prevention measures. (2) low boiling point diluent is added to the product by the customer, and the diluent can volatilize quickly and easily. (3) the weather is hot, the base temperature is high, it is recommended to shade or evening construction. (4) loose porous base, should use special base treatment agent for base treatment, or paint appropriate dilution, the first thin coating, in order to close the base pores. (5) one-component product: the coating film is too thick at one time, so it is recommended to apply it with appropriate thin coating. (6) two-component products: construction shall be completed within the opening hours, especially in high temperature in summer;Avoid introducing a lot of bubbles by stirring at too high speed;If the ratio is not right, bubbles will also form. Solution: for the above reasons to produce a large number of bubbles or pores, it is recommended to remove and redo, or wait until the film dry, and then redo a waterproof layer on top.

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  • Application of polyurethane ink resin
    Application of polyurethane ink resin


    The choice of solvent In the printing ink manufacturing process, in consideration of the overall solvent system of the ink volatility, to improve the printing ink solvent release and reduce the solvent organic solvent residue, the use of solvents are often several volatile mixed solvents.In the printing ink manufacturing process, the main organic solvents are toluene, butanone, cyclohexanone, ethyl acetate, butyl acetate, n-propyl acetate, isopropanol, etc., customers can adjust the volatility of the ink according to seasonal changes. The choice of pigment As a result of the market pigment grade difference, in polyurethane ink for the same resin manufacturers of the same pigment dispersion, ink stability and other aspects of the performance is often a big difference, so it is recommended that users according to their actual customer needs carefully choose pigment. The selection of additives Wax powder: in the production of polyurethane ink, the use of wax powder is often low molecular weight polyethylene wax, the relative molecular weight is generally 1000 ~ 6000, the organic solvent in the ink has a good solubility, and polyurethane resin affinity is good, at the same time has a good chemical stability.Mainly to increase the friction of the surface of the ink film, at the same time to properly alleviate the anti-viscosity of the ink itself. Dispersant: a class of surfactant, mainly used for wetting pigment surface, shorten ink manufacturing time, is conducive to the dispersion of pigment, and sometimes appropriate to reduce the oil absorption of pigment.In the production of high concentration of ink, ink yield can be reduced to prevent the ink pigment particles agglutination and precipitation has a certain effect. Polyurethane resin adhesion promoter: printing inks containing a large number of polar groups, BOPP, PE and so on nonpolar substrate surface even by corona surface treatment, surface tension in 38 dyne ~ 42 dyne, to improve the polyurethane ink on the substrate surface adhesion fastness, often need to add the appropriate ester titanate coupling agent or chlorinated polypropylene adhesion promoter. sinograce chemical is specially designed for polar base material water-based ink, with good adhesion and water-resistant printing, suitable for various materials of ink printing visit us sinograce chemical: https://www.sinogracechem.com Get a Quote Now :sales@sinogracechem.com Telephone               :+86 0551 63459511

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