Water-based adhesive, preparation method, adhesive tape and preparation method thereof

The invention relates to a water-based adhesive, a preparation method, an adhesive tape and a preparation method thereof. The preparation method of the water-based adhesive comprises the following steps of: preparing pre-emulsified liquid, adding 2.5-9.5 parts of reactive emulsifying agent and 0.08-0.9 part of sodium bicarbonate into a pre-emulsifying kettle, mixing with 100-250 parts of deionized water, stirring uniformly, adding 2-30 parts of methacrylic acid or acrylic acid, 1-20 parts of hydroxymethyl acrylamide and ethylhexyl acrylate and the like, stirring uniformly, and adding 150-350 parts of deionized water, the reactive emulsifying agent and the sodium bicarbonate into a reaction kettle; rising the temperature to be 75-85 DEG C, and adding 1-5% of pre-emulsified liquid prepared in the step S1 and diluted liquid prepared by adding 0.3-6 parts of ammonium persulfate and 20-30 parts of deionized water; preserving heat for 10 minutes, starting to drip the pre-emulsified liquid prepared by the step S1 and the diluted liquid prepared by the remaining ammonium persulfate and 20-50 parts of deionized water, and dripping within 2-5 hours completely; preserving heat for 10-60 minutes, then eliminating, reducing the temperature to be below 45 DEG C, neutralizing, discharging, adding a defoaming agent and a sterilizing agent, finally filtering by a net and discharging.