Preparation And Properties Of Sulfonated Water-based Fluorescent Polyurethane Ink

Due to the long-term negative effects of volatile organic compounds(VOCs)on human health and the strict requirements of environmental legislation,the use of solvent inks has been increasingly restricted.In order to avoid the production of volatile organic compounds(vocs),water as an environmentally friendly and cheap solvent has been favored by more and more researchers.Thus,water-based ink emerged.Water-based inks generally consist of binders,pigments,additives and water.Among them,the water-based resin binder is called the "heart" of the ink,which determines the performance of the ink.At present,waterborne polyurethane as ink binder has been widely concerned by people,among which,sulfonated waterborne polyurethane(SWPU)is easier to produce low viscosity,high solid content emulsion,at the same time,its acid and alkali resistance,heat resistance,water resistance and the bonding strength of the substrate have been greatly improved,has a good economic value and market prospects.In this paper,the sulfonate waterborne polyurethane is used as the connection material of waterborne ink,and the fluorescent monomer is introduced to synthesize a kind of sulfonate waterborne polyurethane fluorescent anti-counterfeit ink for plastic packaging films.The first chapter mainly introduces water-based inks,waterborne polyurethanes,sulfonate waterborne polyurethanes,and waterborne fluorescent polyurethanes.The second chapter uses isophorone diisocyanate,1,4-butylene glycol ethyl and sodium ethylenediamine sulfonate(A95)as hard segment,gather adipic acid neopentyl glycol ester diol(PNA)and poly(adipic acid-1,4-butanediol ester diol(PBA)as mixed soft segments,a series of sulfonic acid type waterborne polyurethane emulsion was synthesized.The effects of different mass ratios of PNA and PBA on the properties of polyurethane emulsions and their films were discussed.The structure of WPU was characterized by FTIR.The results showed that SWPU emulsion had good particle size distribution and storage stability.With the increase of PNA in polyols,the crystallinity and tensile strength of WPU film decreased,elongation at break increased,water absorption first decreased and then increased,while water contact Angle first increased and then decreased.The T-peel strength of SWPU emulsion on BOPP film increased first and then decreased,with little difference in thermal stability.When the mass fraction of PNA in polyols is 40%,the comprehensive performance of SWPU is the best.At this point,the T-peel strength of SWPU is 5.0N/25 mm,the water absorption rate at 24 h is 3.95%,the water contact Angle is 75°,and the tensile strength and elongation at break are 33.89 MPa and 737.8%.In the third chapter,the mass ratio of 2: 3 of neopentyl glycol adipate and poly(1,4-butanediol adipate)(PBA)is used as the mixed soft segment.A series of sulfonic acid water-based fluorescent polyurethane emulsions were synthesized by the content of functional fluorescent chain extender N,N-dihydroxyethylaniline-γ-terpyridine(TPPDA),and the structure of FWPU was tested by FTIR.The results show that the FWPU emulsion has good particle size distribution and storage stability.With the increase of TPPDA content,the tensile strength of FWPU increases continuously,while the elongation at break,water absorption at 24 h and crystallization property decrease continuously,the thermal stability increases slightly,and the t-peel strength decreases slightly.The optical performance test results show that the UV maximum absorption peak λmax of the fluorescent monomer TPPDA is 370 nm,and the UV maximum absorption peak λmax of the FWPU is 360 nm.As the content of TPPDA increases,the intensity of the UV absorption peak increases,and the fluorescence intensity Increase first and then decrease.When the TPPDA mass fraction is 0.4%,the fluorescence intensity of the FWPU film reaches the maximum.At this time,the T-type peel strength of the FWPU is 4.8N / 25 mm,and the water absorption rate at 24 h is 3.11%.The tensile strength and elongation at break are respectively 41.73 MPa and 682.4%,the comprehensive performance of water-based polyurethane is the best.In the fourth chapter of this paper,a series of white inks with different pigment-base ratios were prepared by using sulfonate-based water-based fluorescent polyurethane as the ink binder,and titanium dioxide was selected as pigment.The experimental results show that with the increase of the pigment-base ratio,the fineness,particle size,viscosity,and initial drying of water-based fluorescent inks are constantly increasing,while the gloss is continuously decreasing.Adhesion fastness and water resistance tend to worsen with the increase of pigment-base ratio.Water-based fluorescent inks have better anti-blocking properties.When the pigment-base ratio is 1: 2,the overall performance of water-based fluorescence is the best.At this time,the viscosity of the water-based fluorescent ink is 217.6 mPa · s,the gloss is 28.6%,and the initial dryness is 19mm/30 s.The fineness an d particle size are respectively It is 10 μm and 14.12 nm.At the same time,the ink has good water resistance,fastness to adhesion,anti-blocking and fluorescence intensity.