The addition of organo-modified silica particles (OSP) to organic monolayer coatings has been investigated as an alternative to the use of primers or surface pretreatments in galvanised steel substrates. A commercial additive consisting of trifunctional organosilane (alkyl-triethoxysilane) grafted on silica particles was directly incorporated at different concentrations (1, 2.5, 3.5 and 4.5 wt%) as an integral additive in a polyester powder coating. The OSP were characterised physicochemically by means of FTIR and TGA, and the coating formulated by DSC. The anticorrosive properties of the systems were evaluated by means of electrochemical impedance spectroscopy (EIS), showing improvements with all the formulations containing the OSP, especially in the coating with 2.5% OSP. In order to explain this behaviour, morphological (using SEM) and adhesion studies were done. The formation of agglomerates in the powder coatings was detected when the concentration was over 2.5%. There was an improvement in the adhesion of the coating to the substrate for all the samples containing the OSP but especially for that containing 2.5%. The impact resistance was increased too, especially in the formulations with 2.5% and 3.5%.
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机译:(54)标题:具有硅酸盐涂层的固体颗粒(54):FESTKoRPERPARTKEL MIT SILKATBESCHICHTUNG(57)摘要:本发明涉及一种具有二氧化硅涂层的固体颗粒的生产方法,其包括以下步骤:将固体颗粒分散为将其涂覆在水性介质中以产生固体颗粒分散体,通过缓冲系统调节固体颗粒分散体的pH以产生缓冲的固体颗粒分散体,并向缓冲的固体颗粒分散体中添加碱性硅酸盐溶液以形成二氧化硅在涂覆期间将其涂覆在固体颗粒上,其中选择缓冲体系和碱性硅酸盐溶液的量,使得在添加碱性硅酸盐溶液之前和在添加完成之后,缓冲的固体颗粒分散体的pH至少为7.0。碱性硅酸盐溶液的最大含量为11.0。固体颗粒优选是无机固体,特别是