High performance water-based adhesion compositions and applications
View Patent ↗An adhesion composition comprising a) a first polymer that is selected from the group consisting of acrylic polymers, acrylonitrile butadiene, butyl rubber, cellulose acetate, cellulose butyrate, epoxy resins, ethylene vinyl acetate, natural rubber, neoprene, phenolic polymers, polyurethanes, polyvinyl acetate, polyvinyl alcohol, styrene butadiene rubber, casein, dextrin, starch, copolymers thereof and combinations thereof; b) a second polymer selected from the group consisting of ethylene-acrylic acid copolymer, oxidized polyethylene, oxidized ethylene-vinyl acetate copolymer, maleated polyolefin and combinations thereof; and c) a surfactant; where the composition is water-based, having a solids content of greater than about 30% based on the total weight of the composition, with a particle size of about 10 nm to about 2000 nm, and is adapted for adhesion to substrates; and where the first and second polymers are different. The adhesion composition can also comprise a tackifier resin selected from the group consisting of rosin ester resin, rosin acid resin, synthetic hydrocarbon resin, synthetic terpenic resin and combinations thereof. Applications of the composition are also disclosed.
1. An adhesion composition comprising:
(a) a first polymer, having a number average molecular weight greater than about 50,000 Daltons but not greater than about 100,000 Daltons, and chosen from acrylic polymers comprising a majority component of either 2-ethylhexylacrylate or butyl acrylate copolymerized with a minority component of either methyl methacrylate, vinyl acetate, or styrene;
(b) a second polymer different than said first polymer, having a number average molecular weight less than about 20,000 Daltons, and consisting of ethylene-acrylic acid copolymers in combination with an oxidized polyethylene polymer;
(c) surfactant in an amount of about 0.05% to about 0.5%; and
(d) water, where the amount of said water, said first polymer and said second polymer is sufficient to provide the composition with a solids content of greater than about 30% based on the total weight of components (a)-(d) in the adhesion composition and where said first polymer and said second polymer comprise solid particles having a D50 particle size of from about 10 nanometers (nm) to about 2000 nm.
2. The composition of claim 1 wherein said first polymer and said second polymer comprise solid particles having a D50 particle size of from about 30 nm to about 600 nm.
3. The composition of claim 1 wherein said first polymer and said second polymer comprise solid particles having a D50 particle size of from about 50 nm to about 500 nm.
4. The composition of claim 3 , further comprising one or more additives chosen from a tackifier resin, an anti-blocking agent, an anti-oxidant, a stabilizer, a filler, a wetting agent and a defoaming agent.
5. The composition of claim 4 wherein:
(i) the first polymer is present in an amount from about 50 weight % to about 98.5 weight % of the total dry weight of the composition;
(ii) the tackifier resin is present in an amount greater than 0 weight % to about 40 weight % of the total dry weight of the composition; and
(iii) the second polymer is present in an amount from about 2.5 weight % and about 25 weight % of the total dry weight of the composition.
6. The composition of claim 5 in the form of an emulsion having a solids content of from about 30% to about 60% by weight based on the total weight of the composition.
7. A high-performance heat seal adhesive comprising the composition of claim 5 .
8. A water-based ink comprising the composition of claim 1 wherein the solids content is greater than about 50% by weight based on the total weight of the composition.
9. A primer composition comprising the composition of claim 1 .
10. An intercoat composition comprising the composition claim 1 .
11. A water-based flexographic ink comprising the composition of claim 1 .
12. A method of improving the cohesive and adhesive strength of a water-based material comprising adding an amount of the composition of claim 1 to said water-based material whereby at least one of the cohesive and adhesive strength of the water-based material is increased.