Study On Activation Process And Coating Properties Of ABS/PC Resin Surface Before Metallization

With the increasing demand for engineering resin,ABS/PC resin has become a research hotspot.PC is blended into ABS as a reinforcer to form ABS/PC resin,which makes ABS/PC have more excellent impact resistance than ABS and stronger fluidity than PC.It is widely used in the production of automobile interior,communication equipment,electronic appliances,lighting equipment,etc.However,the pure ABS/PC resin has poor conductivity and needs to show metallic luster in practical application,so ABS/PC needs to be metallized.ABS/PC is a composite material,its matrix and reinforced phase properties are different,which leads to the difficulty in the activation process of electroless plating,so it is urgent to develop the activation scheme for ABS/PC engineering resin.In this paper,the best preparation technology of colloidal palladium was researched by studying the effects of process parameters and different additives on the activity and stability of colloidal palladium and the coating performance.A palladium free activation scheme suitable for ABS/PC matrix was explored,and the effects of various parameters on palladium free activation were studied.By the characterization of the starting time,the complete plating time and the glossiness of the coating and the best preparation technology of the colloidal palladium for ABS/PC matrix are obtained:the concentration of Pd Cl₂is 8 g/L,the reaction temperature is 55℃,the reaction time is 10 min,the curing temperature is 70℃,the curing time is 6 h,the feeding time is 40 s,mole ratio of Sn/Pd in the reactant is 10,In the product,mole ratio of Sn/Pd is 55,the HCl concentration is 500 m L/L,vitamin concentration is 2 g/L and sodium dodecylbenzene sulfonate is 4 g/L.The initial plating time and complete plating time of the colloidal palladium were 4 s and 8 s,respectively.The gloss of plating for ABS/PC is 453,and the surface of the coating is flat without missing plating.After being coarsened,a large number of polar groups will be exposed on the surface of ABS/PC matrix.These exposed polar groups will be combined with the metal ions free in the solution,and the metal with catalytic effect can be obtained after reduction.Through electronic balance and scanning electron microscope,the scheme without palladium activation was studied.It was found that after the coarsened matrix was put into the nickel sulfate solution then put into the sodium borohydride solution,a dense and uniform metal deposition layer appeared.Through the study of activation process,the effects of activation solution concentration,activation solution p H,activation time and activation temperature on the deposition of nickel on the substrate surface and the coating properties after reduction were found.Results show that when the activation solution concentration was 75 g/L,the activation solution p H value was 2.5,the activation time was 4 min and the activation temperature was 50℃,the deposited nickel after reduction was even and large,and the coating properties were good.Besides,when the concentration of Na BH₄is 20 g/L and the concentration of Na OH is 20 g/L,the growth of nickel on the surface of the substrate after reduction is compact and evenly distributed.The surface morphology of the coating shows that it has good integrity,compact and flat surface.