Study On Preparation And Structure Of Functional Coatings For Color Printing Drawings

Today there are two kinds of drawings in the field of drawings:blueprinting paper and white drawings.The blueprinting paper has the problems of serious environmental pollution and low efficiency.White drawings have many advantages,such as high efficiency,clear picture,high color density,saturated color,strong stereo sense,good color restoration,etc.Therefore,the development of white drawings is an urgent social need at present.In this paper,a color printing drawing functional coating was studied,which was applied by micro coating.This can not only meet the printing accuracy required by the drawings,but also reduce the production cost of color printing drawings.The main research work includes the following aspects:?1?Selecting the change of light transmittance before and after sedimentation of SiO₂ for 6 h to characterize the dispersion performance of solution and discuss the dispersion mode?ultrasonic dispersion and high-speed dispersion?,the amount of dispersant?SHMP,PAAS and NFC?,the effect of solution pH value on the dispersion properties of fumed SiO₂.The experimental results show that:the ultrasonic dispersion is 18 min,the amount of NFC is 0.8%,and and the pH value of solution is 10,the dispersion stability of SiO₂ solution is best.The mechanism of NFC dispersing fumed SiO₂ is the electrospatial stabilization mechanism.?2?AFM was used to analyze the quality of color printing drawings by ultrasonic dispersion and high-speed dispersion.The experimental results show that the ultrasonically dispersed SiO₂ is uniformly distributed on the paper after coating and is suitable for printing.Then the effects of PAAS dosage and NFC dosage on the quality of color printing drawings were discussed.The experimental results show that the physical properties,optical properties and printing performance of the paper with 1%NFC added are better than those with 1%PAAS.In a comprehensive analysis,it was finally chosen to add 1%NFC as a dispersant for the pigment.Next,the influence of the amount of PVA-1799 on the color printing drawings was discussed.The experimental results show that when the amount of PVA-1799 is 30%,the roughness of the paper sample is 63 ml/min,which is the lowest value.The air permeability of the paper pattern decreased with the increase of the amount of PVA-1799.When the amount of PVA-1799 is 30%,the contact angle reaches a minimum of 43°.As the amount of adhesive increases,the overall change in whiteness is small,the opacity increases,and the gloss decreases.The change of the amount of PVA-1799 has little effect on the ink absorption of the paper sample,but when the amount of PVA-1799 is 30%,the color density of the paper,the color gamut area is relatively good,and the line diffusion area is relatively small.Comprehensive analysis,when the amount of PVA-1799 is 30%,the quality of color drawings is better.Finally,the suitable coating formulation for color printing drawings was determined as follows:SiO₂ 100 g,NFC 1 g,PVA-1799 30 g,CMC 1.5 g,Poly-DMDAAC 5 g,defoamer 0.5 g.The solid content of the coating is 10%and the coating quantity is 3 g/m².?3?By analyzing the physical properties,optical properties,ink absorption values,color densities,color gamut areas and line prints of the color print drawings,the quality of the self-made color print drawings is better than that of the three commercially available color print drawings.Micro-CT,SEM and aperture analysis were used to analyze the coating structure.It was found that the color printing drawings were made by using the leveling property of the coating to uniformly fill the SiO₂ particles in the relatively large gaps on the paper surface,and did not form a thick coating layer on the paper surface.