Pressure sensitive adhesives of acetoacetoxy-alkyl acrylate polymers

A normally tacky composition having an acidic pH and comprising (I) at least about 40 weight percent of at least one polymerized olefinically unsaturated carboxylic acid ester monomer selected from the group consisting of acrylic and methacrylic acid esters having 4 to about 14 carbon atoms and combinations thereof, (II) a polymer having a Tg of about 0.degree. C, or less and containing at least one polymerized functional monomer selected from the group consisting of acetoacetoxyethyl methacrylate, acetoacetoxyethyl arcylate and combinations thereof, the functional monomer being present in an amount from about 0.1 to about 10 weight percent based on the weight of said polymer, and (III) the tetrasodium salt of ethylenediaminetetraacetic acid present in an amount from about 0.5 to about 5 weight percent based on the weight of the polymer;

• wherein the polymer is normally tacky as well as normally tacky when cured.

A water-based latex comprising continuous aqueous medium having dispersed therein (I) particles of a polymer having a Tg of about 0.degree. C. or less and comprising (i) at least about 40 weight percent of at least one polymerized olefinically unsaturated carboxylic ester monomer selected from the group consisting of acrylic and methacrylic acid esters having 4 to about 14 carbon atoms and combinations thereof, and (ii) a functional monomer selected from the group consisting of acetoacetoxyethyl methacrylate, acetoacetoxyethyl acrylate and combinations thereof present in an amount from about 0.1 to about 10 weight percent based on the weight of said polymer, and (II) the terasodium salt of ethylenediaminetetraacetic acid present in an amount from about 0.5 to about 5 weight percent based on the weight of said polymer, wherein upon evaporation of the aqueous medium the latex forms a pressure-sensitive adhesive composition having an acidic pH.

A normally tacky composition comprising (I) a polyacid component selected from the group consisting of (a) polyphosphonic acids, (b) polycarboxylic acids, (c) mixtures of (a) and (b), and (d) salts of (a), (b), and (c), and (II) a polymer having a Tg of about 0.degree. C. or less and containing at least one polymerized functional monomer of formula A:

• ##STR15## in which R.sub.1 is a divalent organic radical of at least 3 atoms in lengths, R.sub.5 and R.sub.6 are independently selected from the group consisting of hydrogen, hydroxy, halo, thio, amino and monovalent organic radicals, and X is --CO--R.sub.4 or --CN wherein R.sub.4 is hydrogen or a monovalent organic radical, said polyacid component being present in an amount effective for increasing cohesive strength under acidic conditions, and wherein the composition is a pressure sensitive adhesive and has a cohesive strength at least about two times greater than the cohesive strength of a composition having substantially identical ingredients but substantially devoid of the polyacid component.

A normally tacky composition comprising (I) a polyacid component selected from the group consisting of (a) polyphosphonic acids, (b) polycarboxylic acids, (c) mixtures of (a) and (b), and (d) salts of (a), (b), and (c), and (II) a polymer having a Tg of about 0.degree. C. or less and containing pendent functional groups of formula B:

• ##STR16## wherein R.sub.1 is a divalent organic radical of at least 3 atoms in length and R.sub.4 is H or a monovalent organic radical, the composition being a pressure sensitive adhesive and having a cohesive strength under acidic conditions at least about two times greater than the cohesive strength of a composition having substantially identical ingredients but substantially devoid of the polyacid component.

A water-based latex comprising a continuous aqueous medium having dispersed therein (I) a polyacid component selected from the group consisting of (a) polyphosphonic acids, (b) polycarboxylic acids, (c) mixtures of (a) and (b), and (d) salts of (a), (b), and (c), and (II) particles of a polymer having a Tg of about 0.degree. C, or less and comprising at least about 0.1 weight percent of at least one polymerized functional monomer of formula A:

• ##STR17## in which R.sub.1 is a divalent organic radical of at least 3 atoms in length, R.sub.5 and R.sub.6 are independently selected from the group consisting of hydrogen, hydroxy, halo, thio, amino and monovalent organic radicals, and X is --CO--R.sub.4 or --CN wherein R.sub.4 is hydrogen or a monovalent organic radical, wherein upon evaporation of the aqueous medium the latex forms a pressure-sensitive adhesive composition having a cohesive strength under acidic conditions at least about two times greater than the cohesive strength of a composition having substantially identical ingredient but substantially devoid of the polyacid component.

A pressure-sensitive adhesive article comprising a substrate coated on at least a portion of one surface thereof with a normally tacky and pressure-sensitive adhesive composition comprising (I) a polyacid component selected from the group consisting of (a) polyphosphonic acids, (b) polycarboxylic acids, (c) mixtures of (a) and (b), and (d) salts of (a), (b), and (c), and (II) a polymer having a Tg of about 0.degree. C. or less and containing at least one polymerized functional monomer of formula A:

• ##STR18## in which R.sub.1 is a divalent organic radical of at least 3 atoms in length, R.sub.5 and R.sub.6 are independently selected from the group consisting of hydrogen, hydroxy, halo, thio, amino and monovalent organic radicals, and X is --CO--R.sub.4 or --CN wherein R.sub.4 is hydrogen or a monovalent organic radical, said polymer also being normally tacky when cured and the pressure-sensitive adhesive composition having a cohesive strength under acidic conditions at least about two times greater than the cohesive strength of a composition having substantially identical ingredients but substantially devoid of the polyacid component.

A mixture comprising (I) a polyacid component selected from the group consisting of (a) polyphosphonic acids, (b) polycarboxylic acids, (c) mixtures of (a) and (b), and (d) salts of (a), (b), and (c), and (II) a polymer containing at least one pendant functional group of formula B:

• ##STR19## in which R.sub.1 is a divalent organic radical of at least 3 atoms in length and R.sub.4 is hydrogen or a monovalent organic radical, the mixture being a pressure sensitive adhesive having a cohesive strength under acidic conditions at least about two times greater than the cohesive strength of a mixture having substantially identical ingredients but substantially devoid of the polyacid component.

A normally tacky composition comprising (I) a polyacid component selected from the group consisting of (a) polyphosphonic acids, (b) polycarboxylic acids, (c) mixtures of (a) and (b), and (d) salts of (a), (b), and (c), and (II) a polymer having a Tg of about 0.degree. C. or less and containing at least one polymerized functional monomer of formula A:

• ##STR20## in which R.sub.1 is a divalent organic radical of at least 3 atoms in length, R.sub.5 and R.sub.6 are independently selected from the group consisting of hydrogen, hydroxy, halo, thio, amino and monovalent organic radicals, and X is --CO--R.sub.4 or --CN wherein R.sub.4 is hydrogen or a monovalent organic radical, said polyacid component being present in an amount effective for increasing cohesive strength under acidic conditions, and wherein the composition is a pressure sensitive adhesive and has a cohesive strength at least about six times greater than the cohesive strength of a composition having substantially identical ingredients but substantially devoid of the polymerized functional monomers of formula A.

A normally tacky composition comprising (I) a polyacid component selected from the group consisting of (a) polyphosphonic acids, (b}polycarboxylic acids, (c) mixtures of (a) and (b), and (d) salts of (a), (b), and (c), and (II) a polymer having a Tg of about of about 0.degree. C. or less and containing pendant functional groups of formula B:

• ##STR21## wherein R.sub.1 is a divalent organic radical of at least 3 atoms in length and R.sub.4 is H or a monovalent organic radical, the compositions being a pressure sensitive adhesive and having a cohesive strength under acidic conditions at least about six times greater than the cohesive strength of a composition having substantially identical ingredients but substantially devoid of the pendant functional groups of formula B.

A water-based latex comprising a continuous aqueous medium having dispersed therein (I) a polyacid component selected from the group consisting of (a) polyphosphonic acids, (b) polycarboxylic acids, (c) mixtures of (a) and (b), and (d) salts of (a), (b), and (c), and (II) particles of a polymer having a Tg of about 0.degree. C. or less and comprising at least about 0.1 weight percent of at least one polymerized functional monomer of formula A:

• ##STR22## in which R.sub.1 is a divalent organic radical of at least 3 atoms in length, R.sub.5 and R.sub.6 are independently selected from the group consisting of hydrogen, hydroxy, halo, thio, amino and monovalent organic radicals, and X is --CO--R.sub.4 or --CN wherein R.sub.4 is hydrogen or a monovalent organic radical, wherein upon evaporation of the aqueous medium the latex forms a pressure-sensitive adhesive composition having a cohesive strength under acidic conditions at least about six times greater than the cohesive strength of a composition having substantially identical ingredients but substantially devoid of the polymerized functional monomers of formula A.

A pressure-sensitive adhesive article comprising a substrate coated on at least a portion of one surface thereof with a normally tacky and pressure-sensitive adhesive composition comprising (I) a polyacid component selected from the group consisting of (a) polyphosphonic acids, (b) polycarboxylic acids, (c) mixtures of (a) and (b), and (d) salts of (a), (b), and (c), and (II) a polymer having a Tg of about 0.degree. C. or less and containing at least one polymerized functional monomer of formula A:

• ##STR23## in which R.sub.1 is a divalent organic radical of at least 3 atoms in length, R.sub.5 and R.sub.6 are independently selected from the group consisting of hydrogen, hydroxy, halo, thio, amino and monovalent organic radicals, and X is --CO--R.sub.4 or --CN wherein R.sub.4 is hydrogen or a monovalent organic radical, said polymer also being normally tacky when cured and the pressure-sensitive adhesive composition having a cohesive strength under acidic conditions at least about thirteen times greater than the cohesive strength of a composition having substantially identical ingredients but substantially devoid of the polymerized functional monomers of formula A.

A mixture comprising (I) a polyacid component selected from the group consisting of (a) polyphosphonic acids, (b) polycarboxylic acids, (c) mixtures of (a) and (b), and (d) salts of (a), (b), and (c), and (II) a polymer containing at least one pendant functional group of formula B:

• ##STR24## in which R.sub.1 is a divalent organic radical of at least 3 atoms in length and R.sub.4 is hydrogen or a monovalent organic radical, the mixture being a pressure sensitive adhesive having a cohesive strength under acidic conditions at least about six times greater than the cohesive strength of a mixture having substantially identical ingredients but substantially devoid of the pendant functional groups of formula B.