Adhesive compositions and articles
Pressure-sensitive adhesive compositions and articles that include a layer of the pressure-sensitive adhesive compositions are provided. The pressure-sensitive adhesive compositions are particularly well suited for use with substrates that have been considered to have difficult to bond to surfaces such as those routinely encountered in the automotive industry. For example, the pressure-sensitive adhesive can be adhered to clear coat compositions, painted surfaces, and various polymeric materials having low energy surfaces (e.g., surfaces having a surface energy no greater than 35 dynes per centimeter).
1. A pressure-sensitive adhesive composition comprising:
a) a styrenic component comprising a first styrenic block copolymer having at least one rubbery block and at least two glassy blocks;
b) a first tackifier that is a linear (meth)acrylic-based polymeric material having a glass transition temperature equal to at least 50° C. and having a weight average molecular weight in a range of 5,000 to 200,000 Daltons; and
c) a second tackifier that is compatible with the at least one rubbery block of the first styrenic block copolymer, the second tackifier being an aliphatic hydrocarbon tackifier, a terpene resin, a terpene phenolic resin, or a mixture thereof.
2. The pressure-sensitive adhesive of claim 1 , wherein the first styrenic block copolymer comprises 5 to 50 weight percent glassy blocks based on a total weight of the first styrenic copolymer.
3. The pressure-sensitive adhesive of claim 1 , wherein the first styrenic block copolymer is a linear triblock copolymer comprising 10 to 35 weight percent glassy blocks and 65 to 90 weight percent rubbery block.
4. The pressure-sensitive adhesive composition of claim 1 , wherein the styrenic component further comprises a second styrenic copolymer that is a styrenic diblock copolymer having a single glassy block and a single rubbery block.
5. The pressure-sensitive adhesive composition of claim 4 , wherein the styrenic diblock copolymer comprises 10 to 50 weight percent glassy block and 50 to 90 weight percent rubbery block.
6. The pressure-sensitive adhesive composition of claim 4 , wherein the styrenic component comprises 70 to 100 weight percent of the first styrenic block copolymer and up to 30 weight percent of the second styrenic copolymer based on a total weight of the styrenic component.
7. The pressure-sensitive adhesive composition of claim 1 , wherein the linear (meth)acrylic-based polymeric material is a polymerized product of a first monomer composition comprising 30 to 100 weight percent of an alkyl (meth)acrylate having a T g greater than 50° C. when polymerized as a homopolymer, 0 to 15 weight percent of a polar monomer, 0 to 50 weight percent of an alkyl (meth)acrylate having a T g no greater than 20° C. when polymerized as a homopolymer, and 0 to 5 weight percent of a vinyl monomer that does not contain a (meth)acryloyl group.
8. The pressure-sensitive adhesive composition of claim 1 , wherein the pressure-sensitive adhesive comprises 1 to 25 weight percent of the first tackifier based on a total weight of the pressure-sensitive adhesive composition.
9. The pressure-sensitive adhesive composition of claim 1 , wherein the pressure-sensitive adhesive comprises 10 to 50 weight percent of the second tackifier based on a total weight of the pressure-sensitive adhesive composition.
10. The pressure-sensitive adhesive compositions of claim 1 , wherein the pressure-sensitive adhesive composition comprises 40 to 60 weight percent of the styrenic component, 1 to 25 weight percent the (meth)acrylic-based polymeric material tackifier, and 10 to 50 weight percent of the second tackifier.
11. The pressure-sensitive adhesive composition of claim 1 , wherein the pressure-sensitive adhesive composition further comprises an elastomeric (meth)acrylic-based polymeric material.
12. The pressure-sensitive adhesive composition of claim 1 , wherein the pressure-sensitive adhesive composition is radiation crosslinked using electron beam radiation.
13. An article comprising:
a first substrate; and
a first pressure-sensitive adhesive layer positioned adjacent to the first substrate, wherein the first pressure-sensitive adhesive layer comprises a pressure-sensitive adhesive composition comprising
a) a styrenic component comprising a first styrenic block copolymer having at least one rubbery block and at least two glassy blocks;
b) a first tackifier that is a linear (meth)acrylic-based polymeric material having a glass transition temperature equal to at least 50° C. and having a weight average molecular weight in a range of 5,000 to 200,000 Daltons; and
c) a second tackifier that is compatible with the rubbery block of the styrenic block copolymer, the second tackifier being an aliphatic hydrocarbon tackifier, a terpene resin, a terpene phenolic resin, or a mixture thereof.
14. The article of claim 13 , wherein the first substrate is a foam.
15. The article of claim 13 , wherein the article is free of a primer layer between the first substrate and the first pressure-sensitive adhesive layer.