Development Of Water-based Gravure Ink On Plastic Film Surface

In order to respond to the green printing call,promote the comprehensive management of organic volatile VOCs,and change the current status of high-grade water-based inks in the domestic ink market mainly rely on imports.It is extremely urgent to independently develop and design new water-based ink resin binder emulsions.Acrylates have been widely concerned and researched because of their low cost and environmental friendliness,and have good film-forming properties.However,the emulsions prepared therefrom have disadvantages such as poor water resistance and low adhesion fastness.This subject uses a pre-emulsified semi-continuous polymerization process with methyl methacrylate(MMA)as the hard segment of the polymerization reaction and butyl acrylate(BA)as the soft segment of the polymerization reaction.The functional monomer dibutyl butyl phthalate(DBI)having internal plasticization was introduced to participate in the copolymerization,the ratio and amount of nonionic alkyl phenol ethoxylate(OP-10)and anionic sodium dodecyl sulphate(SDS)compound emulsifier system,and the amount of initiator ammonium persulfate(APS)were investigated.And the effect of copolymerization hard and soft monomer ratio on the properties of polymer emulsion and its film;the changes of appearance,particle size,viscosity,conversion rate,solid content,mechanical and dilution stability of the polymerization emulsion were analyzed;the adhesion of polymeric emulsions on the surface of polyamide(PA),polyethylene terephthalate(PET)and biaxially oriented polypropylene(BOPP)films was discussed;the film forming property of each group of emulsions and the water absorption rate of the film and the swelling ratio of acid and alkali were tested,and the best experimental conditions for preparing the emulsion were obtained:The amount of APS added was 0.6%,the amount of emulsifier was 3%,and OP-10:SDS=2:4,MMA:BA=45:53,the amount of DBI added was 2%,and the reaction temperature was 78-83?.The overall performance of the emulsion was excellent.The adhesion evaluation on the surface of PA,PET and BOPP films was 5B,4B and 2B,respectively,and the contact angle was 48.3°.In order to further improve the emulsion performance,the silane coupling agent KH570 was introduced and the ketone oxime crosslinking system DAAM-ADH was double modified.The experiment proves that the addition of KH570 can improve the hydrophobicity of the surface of the latex film.Compared with the unmodified emulsion,the contact angle of the latex film with 5%KH570 is 81.7°,which is increased by 69.15%.The introduction of the appropriate amount of DAAM can further enhance the hydrophobic effect.The contact angle of the latex film with 4%KH570 and 1%DAAM is 86.6°,an increase of 79.3%.The conversion rate and stability of the modified emulsion were improved,and the surface of the plastic film was well adhered.The adhesion of the emulsions with 2%KH570 and 3%DAAM on the surface of PA,PET and BOPP films were 6B,6B and 5B,respectively.The dispersion effect of the aqueous ink prepared by the self-made emulsion is comparable to that of the commercially available imported emulsion,and the viscosity of the aqueous ink is largely different,and the viscosity of the self-made emulsion is low.The adhesion evaluation of the ink IM-WR made by the self-made modified resin on the surface of the PA,PET,and BOPP films was 6B,5B,and 5B,respectively,which was higher than the other products under the same ink-making conditions.The intaglio transfer effect of the ink I-WR made by the self-made unmodified emulsion is poor,the whiteness value at the high cell depth is low,and the gravure transfer effect of the IM-WR is close to the standard of the ink obtained by the commercial emulsion.