| In order to obtain excellent acrylate emulsion pressure-sensitive adhesive (PSA), reduce cost of PSA and raise the value of tackifying resin emulsion, the present paper discloses a kind of water dispersion pressure-sensitive adhesive composition made of acrylic(ester) monomers with core-shell polymerization and modified with rosin ester emulsion, with the result that while being a water dispersion type pressure-sensitive adhesive composition, the product-modified displays excellent properties on a par with others similar.Anion surfactant of rosin glyceride polyoxyethylene sodium sulfosuccinate monoester (RGEOS) with different polymerization degree of EO was synthesized for the first time. Surface physical chemistry properties of RGEOS were also measured and the result shows that surface tension (5) varies from 33.50 mN/m to 37.20 raN/m, critical micelle concentration (CMC) from 1.0 mmol/L to 3.6 mmol/L, interface tension (V, with turpentine) from 3.4 mN/m to 4.8 mN/m, lime soap dispersing power (LSDP) from 3.2% to 6.4%, emulsifying power (EP, with turpentine) from 202 s to 310 s, wetting power (WP) from 125 s to 265 s, and the Krafft point is below zero. The relations between surface physicochemical properties of RGEOS and polymerization degree of ethylene oxide (EO) were also studied systemically. With the increasing of polymerization degree of EO (n), foaming power (FP) is rising firstly, and then tending towards stability or dropping a little; the application properties, such as EP and LSDP, become better with increasing of n; wetting power declines.Rosin ester emulsion was made by phase translation emulsifying under atmospheric pressure. The effects of the primary factors on the properties of rosin ester emulsion, such as the quantity and way of addition of emulsifying agent, the processing conditions in the phase inversion process, were investigated: emulsifying temperature is 95 ℃; the speed of stirring and water-dropping is 650 r/min and 45 drop/min respectively. Thus, an aqueous emulsion of rosin ester, the stability of which is over 6 months at room temperature, was prepared with 5%(mass part)emulsifier.Acrylate emulsion was prepared by core-shell emulsion polymerization, and some determinant factors on product properties were discussed in detail as follows: proportion of core-shell, initiator, emulsifier, and phase ratio. The result shows that the optimum conditions are: the quantity of seed emulsion is 12%(mass part), emulsifier and initiator in seed emulsion is 2/3 and 1/3 respectively, and the phase ratio is 1/2.5.The effects of the mass quantity of rosin ester emulsion on the properties of PSA were also studied. The 180° peeling-strength of PSA is rising firstly with the increasing of mass quantity of rosin ester emulsion; it reaches the top when the m(acrylate emulsion)/m(rosin ester emulsion) is 80/20 and then drops. The effect of amount of rosin ester emulsion on probe tack of PSA is similar to that on the 180° peeling-strength. However, the value of probe tack is the biggest at m(acrylate emulsion)/m(rosin ester emulsion)=70/30. The effect of quantity of rosin ester emulsion on the holding power is obvious. When the quantity is very small, the holding power is beginning to reduce. In order to balance the properties of PSA, the optimum rate of /w(acrylate emulsion)/m(rosin-modified emulsion) is elected to be 80/20, and the properties of PSA-modified were tested: the probe tack of adhesive is 12 (steel-ball number); the holding power of PSA is 7 h; the 180° peel-strength is 6N/25mm; and the stability is over 6 months. It was found that the product-modified has excellent properties as PSA compared with others similar.The optimum tackifying resin was found that rosin ester emulsion is the best tackifier to the acrylate emulsion PSA compared with petroleum resin and terpene resin, and then the result was investigated from blending-enthalpy, HLB, molecular weight and its distributing. Finally, the tackifying-mechanism of rosin ester emulsion was explored with adsorption theory, diffusion theory and weak boundary layer theory.
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