The Preparation Of A Waterbased Peelable Coating And An Epoxy Aqueous Dispersion

This paper can be divided into two parts.The first one is the preparation of a waterbased peelable coating,the second is the the preparation of an epoxy aqueous dispersion.In the first part,firstly a polystyrene-acrylate emulsion was synthesized,secongdly modified the emulsion with toughener,remover ,lastly preparated a waterbased peelable coating with some additives.The influence of the proportion between soft monomer and hard monomer,the dosages of toughener,remover on coating's performance by adhesion,flexibility and elongation rate was investigated.Results show that the coating has good adhesion,flexibility and elongation rate when the proportion between soft monomer and hard monomer is 13:20,the dosages of toughener is 4.5%,the dosages of remover is 0.7%.The coating has the follows properties:solid content30%, size18～23nm, pencil hardnessH,viscidity 55～64mP·s,Tg8℃,adhesion grade7,elongation rate300%.It can be used extentively in metal,coatings,glass or plastics for surface protection.In the second part,firstly a reative epoxy dispertant was preparated by using PEG4000 and epoxy128,secondly enlarged the epoxy128 with P,P-iso-propylide- nediphenol,thirdly addied double acidpolyethylene glycol and reactive epoxy dispertant in consequence,lastly preparated an self-mulisifing epoxy aqueous dispersion by converting contryly technique with water. The influence of the proportion between PEG4000 and epoxy128 , the dosages of double acidpolyethylene glycol and reactive epoxy dispertant on the performance of the epoxy aqueous dispersion was investigated. Results show when the proportion between PEG4000 and epoxy128 is 1.25:1 , the proportion between P,P-iso-propylidenediphenol and epoxy128 is 1:2.70, the dosages of double acidpolyethylene glycol and reactive epoxy dispertant are 0.44% and 22.0%,the performance of the epoxy aqueous dispersion is better.It's properties:the solid content30%,size0.58μm,viscidity 4200mP·s. Mixed it with waterbased epoxy curing agent in proportion of 100:29,the dispersion can forming a film in 3 hours,then addied pigments and additives,the dispersion can be made into many sorts of epoxy aqueous dispersion coatings.