Chromium-free photo-sensitive resist for rotary screen printing

Abstract

The invention relates to chromium-free photo-sensitive resist for rotary screen printing, which comprises the following components: polyvinyl alcohol (30%), gelatin, p-diazodiphenylamine paraformaldehyde condensate, polyisocyanate blocks, silicone modified polyurethane resins, trimethylolethane, 3-6 parts of stilbazole dimethyl sulfate salt, hydroquinone, curing agents, polyethyleneimine, ethylamine boron trifluoride salt, benzyl dimethylamine, aluminum chloride hexahydrate, solvents, aluminum chloride hexahydrate, silicone defoaming agents and vitamin E. The chromium-free photo-sensitive resist has the advantages of strong binding force of the high-precision photo-sensitive resist for a rotary printing screen and the rotary printing screen, excellent chemical resistance and abrasion resistance, and high press run; plate making and developing of the rotary printing screen are clear and mesh holes cannot be stopped; through adding the silicone modified polyurethane resin, the tensile property of the rotary printing screen in a printing process is improved, and the service life of the rotary printing screen is prolonged.

Description

Technical field [0001] The invention relates to a rotary screen photosensitive glue, in particular to a chromium-free rotary screen photosensitive glue. Background technique [0002] Rotary screen printing technology is an important large-scale printing technology. It is a printing process that can achieve high resolution, continuous, and extremely high printing resistance. It is mainly used for printing cloth, plastic film and other continuous textiles. Rotary screen photosensitive glue is an important photosensitive material for rotary screen printing. It is usually composed of colloid and photosensitive agent. The colloid is an aqueous emulsion and the photosensitive agent is an aqueous solution of ammonium dichromate. When using, add the sensitizer ammonium dichromate solution to the colloid, stir it evenly, apply immediately after defoaming, dry at a low temperature under 35-40℃, carry out exposure, wash and develop, after drying, then at 180℃ Baking, curing, and finally fo...

AI Technical Summary

Problems solved by technology

However, using ammonium dichromate as a photosensitive agent also has obvious disadvantages: when ammonium dichromate is mixed with the colloid, it must be used immediately, otherwise due to dark reaction, the film will be cross-linked and cannot be developed; ammonium dichromate contains chromium , and chromium is a typical carcinogenic heavy metal, which is extremely toxic to the human body and is also one of the sources of heavy metal pollution in groundwater. During the development process, it is dissolved by water and removed from the nickel mesh. At the same time, the chromium salt in the film also enters the water and is then discharged into the environment, causing water pollution.

However, due to the slow reaction rate of the crosslinking reaction of the acryloyl group caused by the free radical initiator, and the photocrosslinking reaction caused by the free radical is more sensitive to oxygen, oxygen acts as a polymerization inhibitor for the free radical initiator, so, with Photocrosslinking reactions initiated by free radical initiators are still rarely used in screen printing photoresist products