Labeling adhesive
The use of dimer acids with conventional hot melt adhesive polymers provide adhesives particularly useful for bottle labeling. The label, along with the adhesive, can be easily removed from the bottle during the recycling process.
1 . A process for bonding a label to a container comprising applying to at least one substrate surface of a label and/or a container an adhesive, said adhesive comprising a styrenic block copolymer, a tackifier, and an acid functional diluent with an acid number of at least 100, and bringing the substrate surface of said label in contact with the substrate surface of said container.
2 . The process of claim 1 wherein the adhesive further comprises a plasticizer and/or an end block resin.
3 . The process of claim 1 wherein the adhesive comprises from about 10 to about 30% by weight of styrenic block copolymer, from about 35 to about 75% by weight of a tackifier, from about 10 to about 35% by weight of an acid functional diluent with an acid number of at least 100, and up to about 20% of a plasticizer and/or end block resin.
4 . The process of claim 1 wherein the styrenic block copolymer has a melt index of >20.
5 . The process of claim 4 wherein the styrenic block copolymer is present at a level of 14-22% by weight.
6 . The process of claim 1 where the acid functional diluent is a dimer acid.
7 . The process of claim 1 where the tackifier is an acid functional tackifier with an acid number of at least 100.
8 . The process of claim 1 comprising up to about 20% of a benzoate plasticizer.
9 . The process of claim 1 where the styrenic block copolymer has a melt index of >20, the acid functional diluent is dimer acid, and the tackifier is rosin.
10 . The process of claim 1 wherein said label is made of paper or plastic and said container is a bottle or jar made of glass, metal, or plastic.
11 . A method of removing a label from a labeled container, wherein said label was applied to the container using the process of claim 1 , the removal method comprising contacting a labeled container with an alkaline solution.
12 . The method of claim 11 wherein the acid functional diluent is a dimer acid.
13 . The method of claim 11 wherein the styrenic block copolymer has a melt index of >20 and the tackifier is acid functional with an acid number of at least 100.
14 . The method of claim 13 wherein the acid functional diluent is a dimer acid.
15 . The method of claim 11 where the styrenic block copolymer has a melt index of >20, the acid functional diluent is dimer acid, and the tackifier is rosin.
16 . An article comprising a label, wherein the label is attached to the article using the process of claim 1 .
17 . The article of claim 16 wherein the acid functional diluent is a dimer acid.
18 . The article of claim 16 wherein the styrenic block copolymer has a melt index of >20 and the tackifier is acid functional with an acid number of at least 100.
19 . The article of claim 18 wherein the acid functional diluent is a dimer acid.
20 . The article of claim 16 where the styrenic block copolymer has a melt index of >20, the acid functional diluent is dimer acid, and the tackifier is rosin.