| One-component ambient cross-linkable technique which having the advantage of simple operation,lower cost and less energy comsumption is the important method of modifying thermoplastic resins and the reserch foucs of waterborne coating.Two kinds of ambient crosslinkable core-shell acrylic latex,containing acetoacetate groups and organic siliconer,respectively,were synthesized by particle design and optimizing emulsion polymerization process.Metalic coating was studied,which using ambient crosslinkable latex as film forming matrix.The core-shell acrylic latex was synthesized by pre-emulsificational semi continuous emulsion polymerization of acetoacetoxyethyl methacrylate(AAEM), butyl acrylate(BA), methacrylate (MMA), styrene(St),isobornyl methacrylate(IBOMA) and acrylamide(AM) with reactive emulsifier.The effect of emulsifier dosage,mass ratio of emulsifier in core and shell,initiator dosage,monomers proportion and curing agent content on copolymerization behavior and properties of latex film were studied.The latex and its film were characterized by FTIR,TEM,TGA and laser scattering.The results showed that the latex exhibited excellent film forming performance,the latex particles had number-average diameter of 100nm and narrowdispersed polydispersity.The latex film exhibited better mechanical properties and water resistance of 37 hours when the content of emulsifier was 3%,the mass ratio of emulsifier in core and shell was 40/60 respectively,the content of AM,IBOMA,AAEM were respectively 2%,8%,5%,the amount substance ratio of 3-triethoxysilylpropylamine(KH550) and AAEM was 1:1Silicone modified acrylic latexs were prepared by blend and copolymerization,these two modified methods were compared.The results showed that blending modified acrylic latex with nanosilicasol could improve the rheology of latex,reduce sagging and also increase the fullness of film.The stability of emulsion and mechanical properties of film were better when the mass ratio of silicasol and acrylic emulsion was 8:100.Silicone modified core-shell acrylic emulsion was synthesized by copolymerization of acrylic monomers with triethoxylsilane (A151) and 3-methacryloxypropyltrimethoxysilane(A174) respectively.The Tg of latex resin was about 17℃,exhibiting excellent film forming.A174 had a better modified effect on acrylic latex, the film properties were the best when the content of A174 was 10%,water resistance reached 110 hours,water absorbtion was 4.5%.Waterborne metalic coating was prepared by silicone modified acrylic copolymerization latex,waterborne aluminum and waterborne additives.The rheological control agent, celluloseacetate butyrate(CAB),on the stability of metalic coating and glossiness were investigated.The results showed that when the content of CAB,aluminum particles were 1.5% and 20% respectively,the stability of latex and film properties were better.Ambient crosslinkable metalic coating could reduce the―dissolution‖effect of clear coating on metalic coating.
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