Preparation And Properties Of UV-sensitive Resin

With countries around the world advocating and appealing for green environmental protection,traditional thermosetting resin has been gradually washed out due to their large pollution,low curing speed and low production efficiency.As the main representative of the surface treatment of green advanced materials and functional resin.Photosensitive resin is not only environmental friendly,but also convenient for basic research and large-scale industrialization,thus,it is favored by many researchers,which has important theoretical and practical significance in expanding the application field of polymer resin.Acrylic photosensitive resin has the advantages of low cost,wide source,which is one of the most common photosensitive resin,while it has a poor weather resistance,high viscosity,and bad adhesion to the substrate,which limited its application in some areas,and this can be improved through the introduction of functional monomer or more functional groups.Dendritic photosensitive resin is a novel photosensitive resin,which possesses unique structure,functional diversification,and has broad application prospects.In this paper,in order to reduce the viscosity of photosensitive resin and improve the adhesion of the coating on substrate,modified acrylate photosensitive resin and the UV curing coating were prepared.To reduce the use of reactive diluent,improve the curing rate,we prepared dendritic photosensitive resin and dendritic coating,The main contents are listed as follows:(1)The acrylic photosensitive resin was synthesized by using HEA,BA and MMA as raw material through solution free radical polymerization,after optimizing the polymerization conditions,the absolute viscosity of the resin(5600mPa.s)was measured by using NDJ-1.The UV-curable films were prepared by reacting with Acrylic photosensitive resin under the photoinitiator components and UV light,the physical and chemical properties such as hardness,adhesion,brittleness,as well as gloss were tested according to the standard of coating film.The results indicates that the hardness of the cured film is 3H,the adhesion is 4,which is fragile and has poor flow,it need to add the resin dosage of 40?50%of the active diluent monomer,and the film has a small amount of pinhole.(2)The as-synthesized acrylic resin was modified by introducing innovative-C=C activity and-COOH polarity of different functional monomer,such as maleic acid,eleven acid and methylene succinic acid.After comprehensive analysis on the polymerization process and resin properties of appearance,methylene succinic acid was selected as the modified monomer.When the amount of modified monomers accounts for 10%of the total monomer,the modified resin absolute viscosity measured by using NDJ-1 is 1250mPa.s,which decreased about 5 times compared with the pure acrylic resin.The UV-curable films were prepared by reacting with Acrylic photosensitive resin under the photoinitiator components and UV light,the physical and chemical properties such as hardness,adhesion,brittleness,as well as gloss were tested according to the standard of coating film.The results showed that the hardness of the modified acrylate resin curing paint film is 4H,the adhesion is grade 2,and it has a good leveling,it only need to add the resin dosage of 10-20%of the active diluent monomer when curing,and the coating is smooth,the gloss is also good.(3)A series of dendritic photosensitive resin with its core of amine,and terminal group containing different acrylate double bond were synthesized through dispersion method by using active amine(EDA,DETA and TETA),active polyfunctional dilution monomer(TGPDA,ETPTA)as raw material,and it takes advantage of the difference between reactive functional groups.The absolute viscosity of dendritic resin measured by using NDJ-1 are all no more than 50mPa.s,with ultra low viscosity and good hydrodynamic performance.(4)The dendritic coating films were prepared by curing dendritic photosensitive resin whose terminal group is composed of different acrylate double bond and photo initiation agent,as well as other components under the irradiation of UV light.The influence of double bond content on resin curing speed,dry time and gel conversion rate and other performance were investigated.The results show that the synthetic dendritic photosensitive resin curing does not need to add active diluent monomer,and the more the number of acrylate double bond in terminal group is,the curing speed is faster,the surface dry time is shorter,and conversion rate of gel is higher.Active amine of TETA contains six active hydrogen,which can react with ETPTA through Michael addition reaction to obtain the dendrimers resin with the end group containing 12 acrylate double bond,and its curing rate is fastest,its dry time is shortest(only 6?8s),achieving a high gel conversion rate of 97.5%.