Adhesive resin composition and multi-layer laminated structure using the same

1. An adhesive resin composition (III) comprising:

(I) 10 to 90% by mass of a modified polyethylene in which an unsaturated carboxylic acid and/or an unsaturated carboxylic acid derivative unit is grafted to a high molecular weight polyethylene with a melt flow rate (MFR: temperature 190° C., loading 2.16 kg) of 0.1 to 2.0 g/10 minutes, and a density of 0.91 to 0.96 g/cm 3 , which is at least one of (a) a modified high density polyethylene with a melt flow rate of 0.1 to 2.0 g/10 minutes, and a density of 0.93 to 0.96 g/cm 3 , and (c) a modified linear low density polyethylene with a melt flow rate of 0.1 to 20 g/10 minutes, and a density of 0.91 or greater and less than 0.93 g/cm 3 , and

(II) 10 to 90% by mass of an unmodified polyethylene with a melt flow rate (MFR: temperature 190° C., loading 2.16 kg) of 0.1 to 20 g/10 minutes, and a density of 0.86 to 0.96 g/cm 3 , which is at least one of (b′) an unmodified high density polyethylene with a melt flow rate of 0.1 to 20 g/10 minutes, and a density of 0.93 to 0.96 g/cm 3 , (c′) an unmodified linear low density polyethylene with a melt flow rate of 0.1 to 20 g/10 minutes, and a density of 0.91 or greater and less than 0.93 g/cm 3 , and (d′) an unmodified ultra low density polyethylene with a melt flow rate of 0.1 to 20 g/10 minutes, and a density of 0.86 to 0.91 g/cm 3 , and

wherein a ratio MFR(I)/MFR(II), where MFR(I) represents a melt flow rate (MFR: temperature 190° C., loading 2.16 kg) of said modified polyethylene (I) and MFR(II) represents a melt flow rate (MFR: temperature 190° C., loading 2.16 kg) of said unmodified polyethylene (II), is less than 1,and

wherein at least one of (c) the modified linear low density polyethylene, (c′) the unmodified linear low density polyethylene, and (d′) the unmodified ultra low density polyethylene is produced using a single site catalyst,

wherein said at least one of (c) a modified linear low density polyethylene, (c′) an unmodified linear low density polyethylene, and (d′) an unmodified ultra low density polyethylene produced using a single site catalyst is present in said composition, and

wherein a density of said adhesive resin composition (III) is 0.925 to 0.940 g/cm 3 , a content of said unsaturated carboxylic acid and/or unsaturated carboxylic acid derivative unit incorporated therein is at least 0.09% by mass, and a melt flow rate (MFR: temperature 190° C., loading 2.16 kg) is from 0.1 to 2 g/10 minutes.

2. An adhesive resin composition according to claim 1 , wherein said modified polyethylene (I) is a high density polyethylene with a melt flow rate of 0.1 to 2.0 g/10 minutes and a density of 0.93 to 0.96 g/cm 3 , and said unmodified polyethylene (II) is an unmodified high density polyethylene with a melt flow rate of 0.1 to 20 g/10 minutes and a density of 0.93 to 0.96 g/cm 3 .

3. An adhesive resin composition according to claim 1 , wherein said unmodified linear low density polyethylene (c′) and/or said unmodified ultra low density polyethylene (d′) are resin compositions comprising an ethylene/α-olefin copolymer (A) which satisfy conditions (1) to (4) shown below:

(1) a density of 0.86 to 0.94 g/cm 3 ,

(2) a melt flow rate of 0.1 to 20 g/10 minutes,

(3) a molecular weight distribution (Mw/Mn) of 1.5 to 4.5, and

(4) a difference between T 25 , representing a temperature at which 25% of a total content is eluted, determined from an integrated elution curve of an elution temperature vs. elution quantity curve obtained by a temperature rising elution fractionation (TREF) method, and T 75 , representing a temperature at which 75% of said total content is eluted, namely T 75 −T 25 , and a density d which satisfy a relationship of an equation 1, shown below:

T 75 −T 25 ≦−670× d+ 644  (equation 1).

4. An adhesive resin composition according to claim 3 , wherein said ethylene copolymer (A) also satisfies a relationship (5) described below:

(5) a difference between T 25 , representing a temperature at which 25% of a total content is eluted, determined from an integrated elution curve of an elution temperature vs. elution quantity curve obtained by a temperature rising elution fractionation (TREF) method, and T 75 , representing a temperature at which 75% of said total content is eluted, namely T 75 −T 25 , and a density d which satisfy a relationship of an equation 2, shown below:

T 75 −T 25 −300 ×d+ 285  (equation 2).

5. An adhesive resin composition according to claim 3 , wherein said ethylene copolymer (A) is an ethylene copolymer (A1) which satisfies conditions (6) and (7) described below:

(6) a quantity X (% by mass) of an orthodichlorobenzene (ODCB) soluble fraction at 25° C., a density d, and a melt flow rate (MFR) which satisfy relationships of an equation 3 and an equation 4 shown below:

X< 2.0 in cases in which d−0.0081 logMFR≧0.93  (equation 3)

X< 9.8×10 3 ×(0.9300 −d+ 0.008 logMFR) 2 +2.0 in cases in which d− 0.008 logMFR<0.93,   (equation 4)

and

(7) an elution temperature vs. elution quantity curve obtained by a temperature rising elution fractionation (TREF) method which has a plurality of peaks.

6. An adhesive resin composition according to claim 4 , wherein said ethylene copolymer (A) is an ethylene copolymer (A2) which also satisfies conditions (8) and (9) described below:

(8) an elution temperature vs. elution quantity curve obtained by a temperature rising elution fractionation (TREF) method which has only one peak, and

(9) one, or two or more melting point peaks, wherein a highest melting point Tml and a density d satisfy a relationship of an equation 5, shown below:

T ml≧150 ×d− 19  (equation 4).

7. An adhesive resin composition according to claim 6 , wherein said ethylene copolymer (A2) also satisfies a condition (10) described below:

(10) a melt tension (MT) and a melt flow rate (MFR) which satisfy an equation 6 shown below:

logMT≦0.572×logMFR+0.3  (equation 6).

8. An adhesive resin composition according to claim 3 , wherein a halogen concentration of said ethylene copolymer (A) is no more than 10 ppm.

9. An adhesive resin composition according to claim 3 , wherein said resin composition incorporating said ethylene copolymer (A) comprises substantially no additives.

10. An adhesive resin composition according to claim 1 , wherein if aliphatic metal salts exist within said adhesive resin composition, a concentration thereof is less than 100 weight ppm.

11. An adhesive resin composition according to claim 1 , wherein said unsaturated carboxylic acid is an acid anhydride.

12. An adhesive resin composition according to claim 11 , wherein a ring opening ratio of acid anhydride groups of said adhesive resin composition following graft modification is maintained at no more than 10%.

13. An adhesive resin composition according to claim 11 , wherein said acid anhydride is maleic anhydride.

14. A multi-layer laminated structure comprising an adhesive layer formed from an adhesive resin composition according to claim 1 , and at least a principal material layer formed on an outside of said adhesive layer, and a barrier layer formed on an inside of said adhesive layer.

15. A multi-layer laminated structure according to claim 14 , wherein said principal material layer is a high density polyethylene layer and/or a regrind layer using recycled material.

16. A multi-layer laminated structure according to claim 14 , formed from a 3 type 5 layer structure comprising a principal material layer formed from a high density polyethylene layer and/or a regrind layer/an adhesive resin composition layer/a barrier layer/an adhesive resin composition layer/and a principal material layer formed from a high density polyethylene layer and/or a regrind layer.

17. A multi-layer laminated structure according to claim 14 , wherein a high density polyethylene of said principal material layer has a density of 0.93 to 0.97 g/cm 3 and a melt flow rate of 0.01 to 50 g/10minutes.

18. A multi-layer laminated structure according to claim 14 , wherein said barrier layer is at least one material selected from a group consisting of saponified products of ethylene-vinyl acetate copolymers, polyamide resins, polyester resins and vinylidene chloride resins.

19. A multi-layer laminated structure according to claim 14 , wherein an adhesion interface between said adhesive resin composition layer and/or a regrind layer, and said barrier layer is formed as an irregular surface.

20. A multi-layer laminated structure according to claim 19 , wherein viewing an interface structure of said multi-layer laminated structure with a transmission electron microscope at a magnification within a range from 20,000× to 50,000× reveals irregularities with an elevation difference of at least 100 nm.

21. A multi-layer laminated structure according to claim 19 , wherein said barrier layer is formed from a saponified product of an ethylene-vinyl acetate copolymer.

22. A vessel formed from a multi-layer laminated structure according to claim 14 .

23. A vessel according to claim 22 , which is a blow vessel selected from a group consisting of a fuel tank, a food vessel, and an industrial chemical vessel.

24. An adhesive resin composition according to claim 1 , wherein said adhesive resin composition (III) comprises:

(a) 85 to 15% by mass of a modified high density polyethylene with a melt flow rate of 0.1 to 2.0 g/10 minutes, and a density of 0.93 to 0.96 g/cm 3 , and

(b′) 15 to 85% by mass of an unmodified high density polyethylene with a melt flow rate of 0.1 to 20 g/10 minutes, and a density of 0.93 to 0.96 g/cm 3 ,

wherein said adhesive resin composition (III) further comprises (C″) 5 to 60% by mass of a modified and/or unmodified linear low density polyethylene with a melt flow rate of 0.1 to 20 g/10 minutes, and a density of 0.91 or greater and less than 0.93 g/cm 3 , and/or

(d″) 5 to 40% by mass of a modified and/or unmodified ultra low density polyethylene with a melt flow rate of 0.1 to 20 g/10 minutes, and a density of 0.86 to 0.91 g/cm 3 , and (a)+(b ′)+(c″)+(d″) totals 100% by mass, and

said linear low density polyethylene (c″) and/or said ultra low density polyethylene (d″) are ethylene/ct-olefin copolymer which is produced using a single site catalyst.

25. An adhesive resin composition according to claim 1 , wherein said linear low density polyethylene (c) and/or (c′) and/or said ultra low density polyethylene (d′) have a plurality of peaks in an elution temperature vs. elution quantity curve obtained by a temperature rising elution fractionation (TREF) method, and the highest temperature peak among the plurality of peaks is within a range from 85° C. to 100° C.

26. An adhesive resin composition according to claim 1 , wherein said linear low density polyethylene (c) and/or (c′) and/or said ultra low density polyethylene (d′) are ethylene/ci-olefin copolymer which is polymerized with a catalyst obtained by mixing the compounds alto a4 described below:

(a1): a compound represented by a general formula Me 1 R 1 p R 2 q (OR 3 ) r X 1 4-p-q-r wherein, Me 1 represents zirconium, titanium or hafnium; R 1 and R 3 each represent a hydrocarbon group of 1 to 24 carbon atoms; R represents a 2,4-pentanedionato ligand or a derivative thereof, a benzoylmethanato ligand, or a benzoylacetonato ligand or a derivative thereof; X 1 represents a halogen atom; and p, q and r each represent integers which satisfy the ranges 0≦p≦4, 0≦q≦4, 0≦r≦4, and 0≦p+q+r≦4;

(a2): a compound represented by a general formula Me 2 R 4 m(OR 5 ) n X 2 z-m-n wherein, Me 2 represents an element from group 1 to group 3 of the periodic table; R 4 and R 5 each represent a hydrocarbon group of 1 to 24 carbon atoms; X 2 represents a halogen atom or a hydrogen atom (although if X 2 is a hydrogen atom, then Me 2 can only be an element from group 3 of the periodic table); z represents the valency of Me 2 , and m and n each represent integers which satisfy the ranges 0≦m≦z, 0≦n≦z, and moreover 0≦m+n≦z;

(a3): an organic cyclic compound with a conjugated double bond; and

(a4): a modified organic aluminum oxy compound incorporating a Al—O—Al linkage and/or a boron compound.

27. An adhesive resin composition according to claim 24 , wherein said linear low density polyethylene (c) andlor (c′) and/or said ultra low density polyethylene (d′) have a plurality of peaks in an elution temperature vs. elution quantity curve obtained by a temperature rising elution fractionation (TREF) method, and the highest temperature peak among the plurality of peaks is within a range from 85° C. to 100° C.

28. An adhesive resin composition according to claim 24 , wherein said linear low density polyethylene (c) and/or (c′) and/or said ultra low density polyethylene (d′) are ethylene/α-olefin copolymer which is polymerized with a catalyst obtained by mixing the compounds alto a4 described below:

(a 1): a compound represented by a general formula Me 1 R 1 p R 2 q (OR 3 ) r X 1 4-p-q-r wherein, Me 1 represents zirconium, titanium or hafnium; R 1 and R 3 each represent a hydrocarbon group of 1 to 24 carbon atoms; R 2 represents a 2,4-pentanedionato ligand or a derivative thereof, a benzoylmethanato ligand, or a benzoylacetonato ligand or a derivative thereof; X 1 represents a halogen atom; and p, q and r each represent integers which satisfy the ranges 0≦p≦4, 0≦q≦4, 0≦r≦4, and 0≦p+q+r≦4;

(a2): a compound represented by a general formula Me 2 R 4 m (OR 5 ) n X 2 z-m-n wherein, Me 2 represents an element from group 1 to group 3 of the periodic table; R 4 and R 5 each represent a hydrocarbon group of 1 to 24 carbon atoms; X 2 represents a halogen atom or a hydrogen atom (although if X 2 is a hydrogen atom, then Me 2 can only be an element from group 3 of the periodic table); z represents the valency of Me 2 , and m and n each represent integers which satisfy the ranges 0≦m≦z, 0≦n≦z, and moreover 0≦m+n≦z;

(a3): an organic cyclic compound with a conjugated double bond; and

(a4): a modified organic aluminum oxy compound incorporating a Al—O—Al linkage and/or a boron compound.

29. An adhesive resin composition according to claim 1 , wherein said unmodified linear low density polyethylene (c′) and/or said unmodified ultra low density polyethylene (d′) are ethylene/α-olefin copolymer which is produced using a single site catalyst.

30. An adhesive resin composition (III) according to claim 1 ,

wherein the modified polyethylene (I) is the modified high density polyethylene (a) with a melt flow rate of 0.1 to 2.0 g/10 minutes, and a density of 0.93 to 0.96 g/cm 3 , and

wherein the unmodified polyethylene (II) is a mixture of the unmodified high density polyethylene (b′) with a melt flow rate of 0.1 to 20 g/10 minutes, and a density of 0.93 to 0.96 g/cm 3 , the unmodified linear low density polyethylene (c′) with a melt flow rate of 0.1 to 20 g/10 minutes, and a density of 0.91 or greater and less than 0.93 g/cm 3 , and the unmodified ultra low density polyethylene (d′) with a melt flow rate of 0.1 to 20 g/10 minutes, and a density of 0.86 to 0.91 g/cm 3 , and (a)+(b′)+(c′)+(d′) totals 100% by mass.

31. An adhesive resin composition (III) according to claim 1 ,

wherein the modified polyethylene (I) is the modified linear low density polyethylene (c) with a melt flow rate of 0.1 to 20 g/10 minutes, and a density of 0.91 or greater and less than 0.93 g/cm 3 , and

wherein the unmodified polyethylene (II) is a mixture of the unmodified high density polyethylene (b′) with a melt flow rate of 0.1 to 20 g/10 minutes, and a density of 0.93 to 0.96 g/cm 3 , the unmodified linear low density polyethylene (c′) with a melt flow rate of 0.1 to 20 g/10 minutes, and a density of 0.91 or greater and less than 0.93 g/cm 3 , and the unmodified ultra low density polyethylene (d′) with a melt flow rate of 0.1 to 20 g/10 minutes, and a density of 0.86 to 0.91 g/cm 3 , and (c)+(b′)+(c′)+(d′) totals 100% by mass.

32. An adhesive resin composition (III) according to claim 1 ,

wherein the modified polyethylene (I) is a mixture of the modified high density polyethylene (a) with a melt flow rate of 0.1 to 2.0 g/10 minutes, and a density of 0.93 to 0.96 g/cm 3 , and the modified linear low density polyethylene (c) with a melt flow rate of 0.1 to 20 g/10 minutes, and a density of 0.91 or greater and less than 0.93 g/cm 3 , and

wherein the unmodified polyethylene (II) is a mixture of the unmodified high density polyethylene (b′) with a melt flow rate of 0.1 to 20 g/10 minutes, and a density of 0.93 to 0.96 g/cm 3 , the unmodified linear low density polyethylene (c′) with a melt flow rate of 0.1 to 20 g/10 minutes, and a density of 0.91 or greater and less than 0.93 g/cm 3 , and the unmodified ultra low density polyethylene (d′) with a melt flow rate of 0.1 to 20 g/10 minutes, and a density of 0.86 to 0.91 g/cm 3 , and (a)+(c)+(b′)+(c′)+(d′) totals 100% by mass.