Adhesive composition for protective film on painting, and manufacturing process thereof

1. An adhesive composition for a protective film on a painting, consisting of:

100 weight parts of hydrogenated block copolymer having a formula (A-B) n X; and

1 to 20 weight parts of a polar tackifier resin compound,

wherein each block A is a polymer block of one or more mono alkenyl arenes having a number average molecular weight between 3,000 and 60,000 g/mol as styrene equivalent peak molecular weight according to ASTM 3536, and each block B is a controlled distribution copolymer block of at least one conjugated diene and at least one mono alkenyl arene, n is an integer from 2 to 30, and X is coupling agent residue,

wherein the total amount of mono alkenyl arene in the block copolymer is between 15 and 50 percent by weight,

wherein the amount of mono alkenyl arene in each block B is between 10 and 45 percent by weight,

wherein the polar tackifier resin compound has a solubility parameter (SP value) of 8.2 to 9.2 calculated by the Small method using Hoy's constant,

wherein the polar tackifier resin compound has a softening point equal to or greater than 110° C. as determined by the Ring and Ball method (ASTM E-28), and

wherein the polar tackifier resin compound is selected from the group consisting of terpene resin, terpene phenol resin, hydrogenated terpene resin, aromatic-modified terpene resin, and aliphatic cyclic partially saturated hydrocarbon compound.

2. The adhesive composition according to claim 1 , wherein the amount of the polar tackifier compound is 1 to 15 weight parts.

3. The adhesive composition according to claim 2 , wherein the amount of the polar tackifier compound is 1 to 10 weight parts.

4. The adhesive composition according to claim 1 , wherein the SP value of the polar tackifier resin compound is in the range of 8.5 to 9.1.

5. The adhesive composition according to claim 4 , wherein the SP value of the polar tackifier resin compound is in the range of 8.8 to 9.1.

6. The adhesive composition according to claim 1 , wherein the amount of the polar tackifier compound is 1 to 5 weight parts.

7. The adhesive composition according to claim 1 , wherein the polar tackifier resin compound has a softening point equal to or greater than 130° C.

8. The adhesive composition according to claim 1 , wherein the polar tackifier resin compound is selected from the group consisting of terpene resin, terpene phenol resin, hydrogenated terpene resin, and aromatic-modified terpene resin.

9. The adhesive composition according to claim 8 , wherein the polar tackifier resin compound is terpene phenol resin.

10. The adhesive composition according to claim 1 , wherein the polar tackifier resin compound is an aliphatic cyclic partially-saturated hydrocarbon compound.

11. The adhesive composition according to claim 1 , wherein each B block comprises terminal regions adjacent to the A blocks that are rich in conjugated diene and one or more regions not adjacent to the A blocks that are rich in mono alkenyl arene units.

12. The adhesive composition according to claim 1 , wherein each block B has a mono alkenyl arene blockiness index of less than 40 weight %, said mono alkenyl arene blockiness index being the proportion of mono alkenyl arene units in the block B having two mono alkenyl arene neighbors on the polymer chain.

13. The adhesive composition according to claim 12 , wherein each block B has a mono alkenyl arene blockiness index of less than 10 weight %.

14. The adhesive composition according to claim 1 , wherein the coupling efficiency of the block copolymer is equal to or more than 95%.

15. The adhesive composition according to claim 1 , wherein the total amount of mono alkenyl arene in the block copolymer is between 15 and 45 percent by weight.

16. The adhesive composition according to claim 1 , wherein the amount of mono alkenyl arene in each block B is between 10 and 40 percent by weight.

17. The adhesive composition according to claim 16 , wherein the amount of mono alkenyl arene in each block B is between 10 and 25 percent by weight.

18. The adhesive composition according to claim 1 , wherein each block A is a polymer block of one or more mono alkenyl arenes having a number average molecular weight between 3,000 and 15,000 g/mol as styrene equivalent peak molecular weight according to ASTM 3536.

19. The adhesive composition according to claim 1 , the conjugated diene of the block copolymer is one or more selected from the group consisting of butadiene and isoprene.

20. The adhesive composition according to claim 1 , the mono alkenyl arene of the block copolymer is styrene.

21. A protective film for protecting a painting, comprising:

a base material; and

the adhesive composition according to claim 1 .

22. A protective film for protecting a painting, consisting of:

a base layer; and

an adhesive layer including an adhesive composition, the adhesive composition consisting of:

100 weight parts of hydrogenated block copolymer having a formula (A-B) n X; and

1 to 20 weight parts of a polar tackifier resin compound,

wherein each block A is a polymer block of one or more mono alkenyl arenes having a number average molecular weight between 3,000 and 60,000 as styrene equivalent peak molecular weight according to ASTM 3536, and each block B is a controlled distribution copolymer block of at least one conjugated diene and at least one mono alkenyl arene, n is an integer from 2 to 30, and X is coupling agent residue,

wherein the total amount of mono alkenyl arene in the block copolymer is between 15 and 50 percent by weight,

wherein the amount of mono alkenyl arene in each block B is between 10 and 45 percent by weight,

wherein the polar tackifier resin compound has a solubility parameter (SP value) of 8.2 to 9.2 calculated by the Small method using Hoy's constant,

wherein the polar tackifier resin compound has a softening point equal to or greater than 110° C. as determined by the Ring and Ball method (ASTM E-28); and

wherein the polar tackifier resin compound is selected from the group consisting of terpene resin, terpene phenol resin, hydrogenated terpene resin, aromatic-modified terpene resin, and aliphatic cyclic partially saturated hydrocarbon compounds.

23. The protective film according to claim 22 , wherein the film is prepared by a co-extrusion.

24. The protective film according to claim 22 , wherein the film is prepared by solvent coating.

25. An article having a surface protected by the protective film according to claim 22 .

26. The article according to claim 25 , wherein the article is an automobile.

27. A process for manufacturing an adhesive composition in a form of pellet for a protective film used for protecting a painting, the process consisting of the steps of:

dry-blending 100 weight parts of a block copolymer having the formula (A-B) n X with 1 to 20 weight parts of a polar tackifier resin compound to obtain a dry-blend without substantially using a plasticizer oil;

extruding the dry-blend in an extruder to obtain an extrudate;

pelletizing the extrudate with an underwater pelletizer to obtain wet pellets; and

drying the wet pellets to obtain pellets containing the adhesive composition,

wherein each block A is a polymer block of one or more mono alkenyl arenes having a number average molecular weight between 3,000 and 60,000 as styrene equivalent peak molecular weight according to ASTM 3536, and each block B is a controlled distribution copolymer block of at least one conjugated diene and at least one mono alkenyl arene, n is an integer from 2 to 30, and X is coupling agent residue,

wherein the total amount of mono alkenyl arene in the block copolymer is between 15 and 50 percent by weight,

wherein the amount of mono alkenyl arene in each block B is between 10 and 45 percent by weight,

wherein the polar tackifier resin compound has a solubility parameter (SP value) of 8.2 to 9.2 calculated by the Small method using Hoy's constant,

wherein the polar tackifier resin compound has a softening point equal to or greater than 110° C. as determined by the Ring and Ball method (ASTM E-28), and

wherein the polar tackifier resin compound is selected from the group consisting of terpene resin, terpene phenol resin, hydrogenated terpene resin, aromatic-modified terpene resin, and aliphatic cyclic partially saturated hydrocarbon compounds.

28. A process of using the adhesive composition according to claim 1 for preventing a surface pollution, the use comprising the steps of:

providing an article having a surface;

providing a sheet having a base layer;

forming an adhesive layer on the base layer by applying on the base layer the adhesive composition according to claim 1 ; and

pasting the sheet onto the surface.

29. The process according to claim 28 , wherein a surface pollution is prevented for at least seven days at 70° C.