Resin compositions and use of the same

Abstract

Asoft resin composition of the present invention comprises a polyethylene resin (A) and an ethylene/α-olefin random copolymer (B) comprising ethylene and an α-olefin having 3 to 20 carbon atoms at a specific proportion, wherein an MFR and density of the polyethylene resin (A), and a density, intrinsic viscosity, glass transition temperature, crystallinity, molecular weight distribution, B value and gη* values of the copolymer (B) are each in a specific range. The soft resin composition is excellent in melt flow characteristics, namely excellent in moldability, and is capable of providing moldings excellent in balance between pliability and heat resistance. An ethylene/α-olefin copolymer resin composition of the present invention comprises a liner ethylene /α-olefin copolymer (A-α) comprising ethylene and an α-olefin having 4 to 20 carbon atoms and a long-chain branched ethylene/α-olefin random copolymer (B-α) comprising ethylene and an α-olefin having 3 to 20 carbon atoms in a specific proportion, wherein a density and melt flow rate of the copolymer (A-α) and a density, MFR, intrinsic viscosity, glass transition temperature, crystallinity, molecular weight distribution, B value and gη* values of the copolymer (B-α) are each in a specific range. A film of the invention is produced from the resin composition. The ethylene/α-olefin copolymer resin composition is excellent in heat stability and suitability for high-speed molding, and can provide the films excellent in mechanical strength properties, low temperature heat-sealing properties and sealing stability, and further in slip characteristics and anti-blocking properties thereby being excellent in handling properties and suitability for high-speed filling upon packaging by automatic filling machines. The film also exhibits the effect as described above.

What is claimed is:  
     
         1 . A resin composition comprising: 
 a polyethylene resin (A) in an amount of 100 parts by weight; and    a long-chain branched ethylene/α-olefin random copolymer (B) comprising ethylene and an α-olefin having 3 to 20 carbon atoms in an amount of 0.5 to 5000 parts by weight,    wherein the polyethylene resin (A) has:    (a) a melt flow rate (MFR, ASTM D 1238, 190° C., a load of 2.16 kg) of 0.01 to 150 g/10 min; and    (b) a density of 0.901 to 0.970 g/cm 3 , and    wherein the ethylene/α-olefin random copolymer (B) has:    (a) a density of not more than 0.900 g/cm 3 ;    (b) an intrinsic viscosity (I), as measured in decalin at 135° C., of 0.3 to 3.0 dl/g;    (c) a glass transition temperature (Tg) of not more than 50° C.;    (d) a crystallinity, as measured by X-ray diffractometry, of less than 40%;    (e) a molecular weight distribution (Mw/Mn), as measured by GPC, of not more than 3.0;    (f) a B value, as determined by  13 C-NMR spectrum and the following equation, of 1.0 to 1.4; and    (g) a ratio gη* of the intrinsic viscosity (T) determined in the property (b) to the intrinsic viscosity (η) blank  of a linear ethylene-propylene copolymer having the same weight-average molecular weight (measured by a light scattering method) as the copolymer rubber (B) and having an ethylene content of 70% by mol, (η)/(η) blank , of 0.2 to 0.95,      B  value=( P   OE )/(2·( P   E )·( P   O ))    wherein (P E ) and (P O ) are respectively a molar fraction of the units derived from ethylene and a molar fraction of the units derived from the α-olefin in the copolymer rubber (B), and (P OE ) is a proportion of the number of the α-olefin/ethylene sequences to the number of all the dyad sequences.    
     
     
         2 . A soft resin composition comprising: 
 a polyethylene resin (A-X) in an amount of 100 parts by weight; and    a long-chain branched ethylene/α-olefin random copolymer (B-Y) comprising ethylene and an α-olefin having 3 to 20 carbon atoms in an amount of 50 to 5000 parts by weight,    wherein the polyethylene resin (A-X) has:    (a) a melt flow rate (MFR, ASTM D 1238, 190° C., a load of 2.16 kg) of 3 to 150 g/10 min; and    (b) a density of 0.901 to 0.970 g/cm 3 , and    wherein the ethylene/α-olefin random copolymer (B-Y) has:    (a) a density of not more than 0.900 g/cm 3 ;    (b) an intrinsic viscosity (I), as measured in decalin at 135° C., of 0.3 to 3.0 dl/g;    (c) a glass transition temperature (Tg) of not more than −50° C.;    (d) a crystallinity, as measured by X-ray diffractometry, of less than 40%;    (e) a molecular weight distribution (Mw/Mn), as measured by GPC, of not more than 3.0;    (f) a B value, as determined by  13 C-NMR spectrum and the above equation, of 1.0 to 1.4; and    (g) a ratio gη* of the intrinsic viscosity (T) of said copolymer rubber (B) determined in the property (b) to the intrinsic viscosity (I)bl,ank of a linear ethylene-propylene copolymer having the same weight-average molecular weight (measured by a light scattering method) as the copolymer rubber (B) and having an ethylene content of 70% by mol, (η)/(η) blank , of 0.2 to 0.95.    
     
     
         3 . An ethylene/α-olefin copolymer resin composition comprising: 
 a polyethylene resin (A-α) in an amount of 100 parts by weight; and  
 a long-chain branched ethylene/α-olefin random copolymer (B-α) in an amount of 5 to 67 parts by weight,  
 wherein the polyethylene resin (A-α) is a linear ethylene/α-olefin copolymer (A-0) comprising ethylene and α-olefin having 4 to 20 carbon atoms and has:  
 (a) a density of 0.901 to 0.940 g/cm 3 ; and  
 (b) a melt flow rate (MFR) of 0.01 to 20 g/10 min, and  
 wherein the long-chain branched ethylene/α-olefin random copolymer (B-α) has:  
 (a) a density of 0.860 to 0.900 g/cm 3 ;  
 (b) a melt flow rate (MFR) of 0.01 to 20 g/10 min;  
 (c) an intrinsic viscosity (η), as measured in decalin at 135° C., of 0.3 to 3.0 dl/g;  
 (d) a glass transition temperature (Tg) of not more than −50° C.;  
 (e) a crystallinity, as measured by X-ray diffractometry, of less than 40%;  
 (f) a molecular weight distribution (Mw/Mn), as measured by GPC, of not more than 3.0;  
 (g) a B value, as determined by  13 C-NMR spectrum and the above equation, of 1.0 to 1.4; and  
 (h) a ratio gη* of the intrinsic viscosity (η) determined in the property (c) to the intrinsic viscosity (η) blank  of a linear ethylene-propylene copolymer having the same weight-average molecular weight (measured by a light scattering method) as the copolymer rubber (B) and having an ethylene content of 70% by mol, (η)/(η) blank , of 0.2 to 0.95.  
 
     
     
         4 . The resin composition as claimed in any one of    claims 1    to    3   , wherein the ethylene/α-olefin random copolymer is a ethylene/α-olefin random copolymer prepared by randomly copolymerizing ethylene and an α-olefin having 3 to 20 carbon atoms in the presence of a metallocene catalyst comprising a metallocene compound represented by the following formula (I):  
                 
 
       wherein M is a transition meta of Group IVB of the periodic table, 
 R 1  is a hydrocarbon group having 1 to 6 carbon atoms;  
 R 2 , R 4 , R 5  and R 6  may be identical with or different from each other and are each hydrogen or a halogen atom, or a hydrocarbon group of 1 to 6 carbon atoms,  
 R 3  is an aryl group of 6 to 16 carbon atoms which may be substituted with a halogen atom, a hydrocarbon group of 1 to 20 carbon atoms or an organic silyl group,  
 X 1  and X 2  are each independently hydrogen or a halogen atom, or a hydrocarbon group of 1 to 20 carbon atoms, a halogenated hydrocarbon group of 1 to 20 carbon atoms, an oxygen-containing group or a sulfur-containing group, and  
 Y is a divalent hydrocarbon group of 1 to 20 carbon atoms, a divalent halogenated hydrocarbon group of 1 to 20 carbon atoms, a divalent silicon-containing group, a divalent germanium-containing group, a divalent tin-containing group, —O—, —CO—, —S—, —SO—, —SO 2 —, —NR 7 —, P(R 7 )—, —P(O)(R 7 )—, —BR 7 — or —AlR 7 — (in the formulae, the R 7  is hydrogen or a halogen atom, or a hydrocarbon group of to 20 carbon atoms or a halogenated hydrocarbon group of to 20 carbon atoms).  
 
     
     
         5 . A film made from the resin composition as claimed    claim 3    or    4   .  
     
     
         6 . The film as claimed in    claim 5   , which is produced inflation molding.