Fast setting starch-based corrugating adhesive having partially hydrolyzed water soluble polyvinyl alcohol component
OwnerPaul L. Krankkalainventor
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Abstract
Corrugating adhesives free of incompatibility problems with water soluble partially hydrolized polyvinyl alcohol comprise a major portion of water, starch, strong base, a boric acid compound and a partially hydrolized water soluble polyvinyl alcohol composition.
Claims17
An aqueous fast-setting corrugating adhesive composition which comprises, in an aqueous emulsion, a major proportion of water, about 5 to 50 parts of starch per each 100 parts of adhesive, sufficient alkali metal hydroxide to provide an alkaline pH, about 0.1 to 5 parts of a boric acid compound per each 100 parts of water, and an effective amount of a cold water soluble, partially hydrolyzed polyvinyl alcohol composition having a degree of hydrolysis of less than about 91%, sufficient to increase the rate of green bond formation wherein the concentration of the polyvinyl alcohol composition in the adhesive composition is about 0.01 to 1.25 parts of the polyvinyl alcohol composition per 100 parts of the adhesive composition.
An aqueous fast-setting corrugating adhesive composition which comprises in an aqueous emulsion a major proportion of water, about 5 to 100 parts of starch, about 0.2 to 0.75 parts of an alkali metal hydroxide to provide a pH greater than about 9, about 0.1 to 5 parts of a boric acid compound, and about 0.01 to 1.5 parts of a cold water soluble, partially hydrolyzed polyvinyl alcohol composition having a degree of hydrolysis of about 87% to 91%, a particle size of less than about 80 mesh, sufficient to increase the rate of green bond formation.
An aqueous, fast-setting corrugating adhesive composition which comprises in an aqueous emulsion a major proportion of water, about 5 to 50 parts of starch per each 100 parts of adhesive, sufficient alkali metal hydroxide to provide an alkaline pH, about 0.1 to 5 parts of a boric acid compound per each 100 parts of water, and about 0.01 to 1.5 parts by weight of a soluble polyvinyl alcohol composition, having a degree of hydrolysis of about 91% or less per each 100 parts of adhesive, sufficient to increase the rate of green bond formation of the adhesive at temperatures below the temperature required to solubilize fully hydrolyzed polyvinyl alcohol in a corrugating adhesive.
An aqueous, fast setting corrugating adhesive composition which consists essentially of, in a silicate-free aqueous emulsion, a major proportion of water, about 5 to 50 parts of starch per each 100 parts of adhesive, about 0.2 to 0.75 parts by weight of sodium hydroxide per each 100 parts of the adhesive, about 0.01 to 1.5 parts by weight of a cold water soluble polyvinyl alcohol composition having a degree of hydrolysis of about 87 to 89%, wherein the particle size of the polyvinyl alcohol is less than about 80 mesh, about 0.1 to 5 parts of a boric acid compound per each 100 parts of water, wherein the starch is present in the form of an ungelatinized starch phase suspended in a carrier phase of gelatinized starch in an aqueous emulsion having about 0.1 to 10 parts of gelatinized starch and about 0.01 to 40 parts of ungelatinized starch, wherein the polyvinyl alcohol composition is a low molecular weight polyvinyl alcohol which is a 4 wt-% aqueous solution has a Brookfield viscosity of about 4-10 cP at 20.degree. C.
Dependencies are inferred from the claim text.