Silicon Sol And Acrylate Polyurethane Hybrid Some Preparation And Its Application

The acrylic based polyurethane coatings have the advantages of soft paint film,well abrasive resistance and hydrolysis resistance. The silica sol is a high hardening,well solvent resistance engineering plastics with enhanced adhesive property. It isassume that we can combine PUA with silica sol together have complementaryadvantages. It shows concretely as follows: Applied to general purpose on any surface,well scratch resistance, high hardness, resistance to soiling, good fullness and chemicalresistance.The SPUA was prepared via in-situ dispersion polymerization，methods usingIPDI,PPG，DMPA,TMP and Silica sol as the experimental objects，specifically dealswith each empirical factor influence on properties of SPUA hybrid dispersions andfilms，to definite the optimum technology parameter as follows: R value was1.3to1.4,the DMPA account for6%proportion in the total of PU quality, the TMP account for1%proportion in the total of PUA quality, the neutralization value was90%, the silicasol account for15%proportion in the total of PUA quality, control the chain-extendersquantity-NH2content of-NCO volume ratio is0.7, the AIBN account for1%proportion in the total of total acrylate monomer quality.Stability and theological properties of the hybrid dispersion were studiedqualitatively, the results showed as follows: Introducing the right amount of silica Solhas no influence on the stability of the system. The SPUA of apparent viscosity ofmixed aqueous dispersions of turn decreased rather dramatically which has15%-5%silica sol. The SPUA hybrid dispersions’s [w(silica sol)=15%]Viscosity shear decrease over timeunder the action of a constant shear rate. The viscosity after falling to a certain extent isno longer reduced when shearing time long enough, is is referred to as a thixotropicproperty of the resin. The aqueous SPUA dispersion took on the behavior ofpseudoplastic fluid when the ratio of m(Silica-sol)/m(SPUA) above and beyond fifteenpercent.In order to explain the relationship between microscopic structure and physicalperformance of SPUA hybrid aqueous dispersions, especially the interaction of twophase, infrared spectroscopy(FT-IR), the projection electron microscope(TEM),scanning electron microscopy(SEM), nanometer particle size analysis(DLS) were used, the results confirmed hydrogen bonding is existent between the silanol and urethanebonds, SiO2particles with nanometer level was dispersed in SPUA hybrid aqueousdispersions, because of SiO2, the phase structure of water dispersion system becomesmore homogeneous, but one small part of coacervate caused a certain extent reductionof particle size.The mutual relationship between aqueous dispersions, film-forming auxiliariesand paint additive was studied, using silica sol acrylic polyurethane hybrid dispersions(SPUA) as main film-forming, and the best formula of SPUA coating was filtrated byorthogonal experimental method: flatting agent (DSX-2000) added0.5%;Adding filmforming additives (propylene glycol ether and benzene methanol with9:1complexusing)5%; Adding foam suppressor (BYK-028)0.1%concluded; polyurethanethickener (DSX-1550) water in accordance with the1:1ratio of dilution, added0.5%;At the same time, storage stability, good brushing performance, the film ’sperformance is high, SPUA can be successfully applied in waterborne wood coatingsfield.