Foamed hot melt adhesive composition for bonding packs of containers

1. A container pack comprising a plurality of containers, wherein the containers are bonded to each other with a foamed hot melt adhesive composition, and wherein when two 1.5 liter PET containers are bonded together by applying two dots of the foamed hot melt adhesive composition of 60 mg per dot to each of the two 1.5 liter PET containers and then an adhesive to adhesive bond is formed, the foamed hot melt adhesive composition provides a maximum separation force of from about 80 N to about 200 N.

2. The container pack according to claim 1 , wherein the containers are bottles or cans.

3. The container pack according to claim 1 , wherein the containers are PET bottles.

4. The container pack according to claim 1 , wherein the hot melt adhesive composition comprises:

a) at least one polymer; and

b) at least one tackifying resin.

5. The container pack according to claim 4 , wherein the hot melt adhesive composition further comprises at least one wax.

6. The container pack according to claim 1 , wherein the hot melt adhesive composition has a Brookfield viscosity at a temperature of 190° C. in the range from about 200 to about 13,000 mPa·s.

7. The container pack according to claim 4 , wherein the at least one polymer comprises at least one block copolymer.

8. The container pack according of claim 4 , further comprising a plasticizer.

9. The container pack according to claim 1 , wherein the hot melt adhesive composition comprises:

a) from about 35 to about 60 weight percent of at least one homogenous linear or substantially linear interpolymer of ethylene and α-olefin;

b) from about 5 to about 25 weight percent of at least one block copolymer;

c) from about 25 to about 45 weight percent of at least one tackifying resin; and

d) less than 10 weight percent of at least one wax;

wherein the sum of components a), b) and c) amounts to at least 85 weight percent of the total adhesive composition, and

wherein the composition has a Brookfield viscosity at a temperature of 190° C. in the range from about 7,000 to about 12,000 mPa·s.

10. The container pack according to claim 7 , wherein the at least one block copolymer is selected from the group consisting of styrene-ethylene/butylene-styrene (SEBS) and styrene-ethylene/propylene-styrene (SEPS).

11. The container pack according to claim 1 , wherein the foamed hot melt adhesive composition has a density of from about 0.40 g/ml to about 0.80 g/ml.

12. The container pack according to claim 1 , wherein the hot melt adhesive composition comprises:

a) from 15% to 85% by weight of at least one block copolymer;

b) from 5% to 60% by weight of at least one tackifying resin; and

c) at least one liquid plasticizer.

13. The container pack according to claim 1 , wherein when two 1.5 liter PET containers are bonded together by applying two dots of the foamed hot melt adhesive composition of 60 mg per dot to each of the two 1.5 liter PET containers and then an adhesive to adhesive bond is formed, the foamed hot melt adhesive composition provides a maximum separation force of from about 91 N to about 200 N.

14. The container pack according to claim 1 , wherein when two 1.5 liter PET containers are bonded together by applying two dots of the foamed hot melt adhesive composition of 60 mg per dot to each of the two 1.5 liter PET containers and then an adhesive to adhesive bond is formed, the foamed hot melt adhesive composition provides a maximum separation force of from about 95 N to about 200 N.

15. The container pack according to claim 1 , wherein when two 1.5 liter PET containers are bonded together by applying two dots of the foamed hot melt adhesive composition of 60 mg per dot to each of the two 1.5 liter PET containers and then an adhesive to adhesive bond is formed, the foamed hot melt adhesive composition provides a maximum separation force of from about 95 N to about 190 N.

16. A container pack comprising:

a plurality of containers bonded to each other with a foamed hot melt adhesive composition, the foamed hot melt adhesive composition providing a maximum separation force of from about 80 N to about 200 N when tested by applying two dots of foamed hot melt adhesive composition of 60 mg per dot to each of two 1.5 liter polyethylene terephthalate containers and bonding the containers together by contacting the two dots on a first of the two containers to the two corresponding dots on the other of the two containers to form an adhesive to adhesive bond, separating the bottles from one another, and measuring the maximum separation force with a force gauge.

17. The container pack of claim 16 , wherein the foamed hot melt adhesive composition provides a maximum separation force of from about 91 N to about 200 N when tested by applying two dots of foamed hot melt adhesive composition of 60 mg per dot to each of two 1.5 liter polyethylene terephthalate containers and bonding the containers together by contacting the two dots on a first of the two containers to the two corresponding dots on the other of the two containers to form an adhesive to adhesive bond, separating the bottles from one another, and measuring the maximum separation force with a force gauge.

18. The container pack of claim 16 , wherein the foamed hot melt adhesive composition provides a maximum separation force of from about 95 N to about 190 N when tested by applying two dots of foamed hot melt adhesive composition of 60 mg per dot to each of two 1.5 liter polyethylene terephthalate containers and bonding the containers together by contacting the two dots on a first of the two containers to the two corresponding dots on the other of the two containers to form an adhesive to adhesive bond, separating the bottles from one another, and measuring the maximum separation force with a force gauge.

19. The container pack of claim 16 , wherein the containers are bottles or cans, formed from at least one of polyethylene terephthalate, a polyolefin, glass, and metal.

20. The container pack of claim 16 , wherein each container of the plurality of containers is separable from the remaining containers with a separation force of from about 91 N to about 200 N.