Emulsion

Generally, emulsion consists of three basic PVA, sensitizer, dispersion and other composing elements are countlessly many including wetting agents, flow agents, defoamers, plasticizers, dyes. Issue is how to draw these harmony can be the most difficult part and undiluted solution of emulsion is consisting of polymer (vinyI-covinyI acetate) that is a polymer of both PVOH(polyvinyl alcohol, its chemical name: PVA ) and PVA(Polyvinyl acetate, its chemical name: PVAC) and water if looking at very carefully and a sphere is formed as these are mixed. At this time, PVOH is located in the outer side and PVA is located in the inner side. In the future, if exposing to the UV light in a condition of agitation with diazo, alternating joint with each particles will be caused. Emulsion typediazo type : is developed for substitution for dichromic acid series as the most general emulsion and main components can be divided into PVOH(polyvinyl alcohol), PVA(polyvinyl acetate), DIAZO and displays a crosslink with PVOH and PVA by the reaction of diazo under UV light. At this moment, judge between solvent resistance and water resistance qualities according to the ratio of solvent resistance PVOH or water proofing PVA. Generally oily nature emulsion is the ratio between PVOH and PVA is 6 : 4 and water nature emulsion is the ratio about 2 : 8. Emulsion of diazo type is excellent and can be obtained minute resolution, is easy to form pattern and is used for general printing a lot.SBQ type : is called an emulsion for guttation and its main components are consisted of PVOH, PVA and SBQ and is used general diazo or monomer or other photopolymer chromophore as a photosentisizer. Differing from diazo, this photopolymer -the connection with particles such as PVOH or PVA is not thorough - and also has time limits finishing actions within short time and therefore, cross-linking density is relatively weak as compared to diazo series or dual cure series. However, efficiency in performance using very fast exposure time can be improved and stable printing effect can be obtained.High functional polymer type : Main components are PVOH, PVA, monomer and diazo and acrylate, that is, acrylic monomo is added on emulsion. The acrylate existing in emulsion performs the role of light accelerant and advance exposure time by helping reaction of diazo. Also, acrylate helps combination in PVOH and PVA together with diazo. And, acting to improve water resistance qualities to each PVOH and solvent resistance to PVA and give more enhanced combination formation of particles. However, reaction to UV light is relatively mile, plate making work can not be performed without diazo. Emulsion of polymer type is far superior and can be obtained minute resolution and used for fine pattern printing as water resistance qualities is outstanding at the same time as solvent resistance. If you want to obtain high quality printing, all working condition should be met, but especially using what type of emulsion is to be used can make the difference in flexibility of emulsion film, flatness of emulsion film, size and stability and so forth.Sejin Smark Co.,Ltd. specifies and is using SF -2 as a main specification item and this is an emulsion displaying excellence in resolution, solvent resistance, flexibility of emulsion film and humidity as compared to other emulsions.