| 摘要 |
PURPOSE:To provide a pressure-sensitive adhesive which has excellent tack, cohesive force and adhesion to polyolefin resins, by incorporating a water- insoluble solid aziridine compd. in an aq. dispersion of an emulsion polymer of a carboxylic acid-contg. acrylic resin. CONSTITUTION:A compsn. consists of an aq. dispersion (a) obtd. by neutralizing 100pts.wt. (on a solid basis) emulsion polymer of a tacky acrylic resin contg. 0.5-10wt% carboxylic acid-contg. monomer in its constitutional component with ammonia or amine and a dispersion (b) of 0.005-5pts.wt. water-insoluble aziridine compd. which contains at least two aziridinyl groups per molecule and is a solid at room temp. When the aziridine compd. is liquid, no effect can be obtd., because a crosslinking reaction takes place at the interface between the fine powder of the acrylic resin and that of the crosslinking agent and hence the aziridine compd. is liable to remain in the adhesive as unreacted material. It is believed that when the crosslinking agent is a liquid at room temp. a trace amount of unreacted crosslinking agent left behind has a bad effect on the physical properties of the adhesive.
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