Water-dispersible pressure-sensitive adhesive and tape made therewith

Claim 1

Normally tacky and pressure-sensitive water-dispersible adhesive especially suitable for splicing carbonless paper, comprising the blended reaction product of (a) 100 parts by weight of a copolymer of monomers consisting essentially of (1) about 60-85 weight percent of at least one monomeric acrylic acid ester of nontertiary alkyl alcohol having 4-14 carbon atoms, and, correspondingly, (2) about 40-15 weight percent of vinyl carboxylic acid, (b) about 50 to 250 parts by weight of ethoxylated plasticizing components, sufficient to impart adhesion values such as to cause the adhesive to delaminate kraft paper when tested as described herein, consisting essentially of at least one of the following: (1) up to about 125 parts by weight, but not so much as to cause adhesive separation, of one or more OH-functional ethoxylated plasticizers and (2) one or more electrolyte-tolerant complex acidic esters of phosphoric acid and an ethoxylated nonionic surfactant, and (c) alkaline hydroxide consisting essentially of (1) sodium hydroxide, lithium hydroxide, or both sodium hydroxide and lithium hydroxide, in an amount sufficient to enhance shear strength and minimize bleeding but insufficient to cause separation of any OH-functional ethoxylated plasticizer present, not exceeding about 0.07 hydroxyl equivalent if OH-functional ethoxylated plasticizer is the only plasticizing component present, and (2) potassium hydroxide in an amount sufficient to promote water solubility.