Propylene-based resin composition

1. A propylene-based resin composition characterized by comprising from 1 to 99 parts by weight of a propylene-based polymer (α) whose melt flow rate (MFR) at 230° C. under a load of 2.16 kg obtained according to ASTM D1238E is from 0.1 to 500 g/10 min and from 1 to 99 parts by weight of an olefin-based resin (β) satisfying the following requirements (I) to (V) (in which a sum of the (α) and the (β) is 100 parts by weight):

(I) the olefin-based resin (β) includes a grafted olefin-based polymer [R1] having a main chain comprising an ethylene/α-olefin copolymer and at least one side chain comprising an ethylene polymer;

(II) the olefin-based resin (β) has a melting peak in a range of from 60 to 130° C. in a differential scanning calorimetry (DSC) measurement and a melting heat quantity ΔH at the melting peak is in a range of from 5 to 100 J/g;

(III) a percentage E of an ortho-dichlorobenzene soluble component at 20° C. or lower measured by cross-fractionation chromatography (CFC) is 45% by weight or less;

(IV) a glass transition temperature Tg measured by differential scanning calorimetry (DSC) is in a range of from −80 to −30° C.; and

(V) an intrinsic viscosity [η] measured in decalin at 135° C. is in a range of from 0.1 to 12 dl/g.

2. The propylene-based resin composition according to claim 1 , wherein the side chain of the grafted olefin-based polymer [R1] has a weight average molecular weight in a range of from 500 to 10000.

3. The propylene-based resin composition according to claim 1 , wherein the side chain is present with an average frequency of from 0.3 to 20 per 1000 carbon atoms included in the main chain of the grafted olefin-based polymer [R1].

4. The propylene-based resin composition according to claim 1 , wherein the olefin-based resin (β) further satisfies the following requirement (VI):

(VI) when the MFR of the olefin-based resin (β) at 190° C. under the load of 2.16 kg obtained according to ASTM D1238E is M g/10 min and the intrinsic viscosity [η] of the olefin-based resin (β) measured in decalin at 135° C. is H g/dl, a value A represented by the following relational equation (Eq-1) is in a range of from 30 to 280:

A=M /exp(−3.3 H )  (Eq-1)

5. The propylene-based resin composition according to claim 1 , wherein the olefin-based resin (β) further satisfies the following requirement (VII):

(VII) in a four-component approximation by a Lorentz function performed for a free induction decay curve obtained by a Carr Purcell Meiboom Gill method in a pulsed nuclear magnetic resonance (pulsed NMR) measurement at 200° C., a spin-spin relaxation time (T2) of a component having a highest mobility is in a range of from 150 to 500 ms and an abundance ratio of the component is in a range of from 15 to 50%.

6. A method for producing the olefin-based resin (β) according to claim 1 , comprising a step of copolymerizing ethylene with at least one α-olefin selected from α-olefins having 3 to 20 carbon atoms in the presence of an olefin polymerization catalyst including the following components (A) to (C):

(A) a crosslinking metallocene compound represented by the following general formula (I);

(B) a transition metal compound represented by the following general formula [B]; and

(C) at least one compound selected from an organometallic compound (C-1), an organoaluminum oxy compound (C-2), and a compound (C-3) that reacts with the crosslinking metallocene compound (A) or the transition metal compound (B) to form a pair of ions,

(in the formula (I), R 1 , R 2 , R 3 , R 4 , R 5 , R 8 , R 9 , and R 12 each independently represent a hydrogen atom, a hydrocarbon group, a silicon-containing group, or a hetero atom-containing group other than silicon-containing groups, in which adjacent two groups of R 1 to R 4 may bond to each other to form a ring;

R 6 and R 11 are the same atom or the same group selected from a hydrogen atom, hydrocarbon groups, silicon-containing groups, and hetero atom-containing groups other than silicon-containing groups, R 7 and R 10 are the same atom or the same group selected from a hydrogen atom, hydrocarbon groups, silicon-containing groups, and hetero atom-containing groups other than silicon-containing groups, in which R 6 and R 7 may bond to each other to form a ring, and R 10 and R 11 may bond to each other to form a ring, provided that not all of R 6 , R 7 , R 10 , and R 11 are hydrogen atoms;

R 13 and R 14 each independently represent an aryl group;

M represents a titanium atom, a zirconium atom, or a hafnium atom;

Y 1 represents a carbon atom or a silicon atom;

Q represents a halogen atom, a hydrocarbon group, a halogenated hydrocarbon group, a neutral conjugated or non-conjugated diene having 4 to 10 carbon atoms, an anion ligand, or a neutral ligand capable of being coordinated with a lone pair of electrons, and j represents an integer of from 1 to 4, in which when j is an integer of 2 or larger, a plurality of Qs each may be the same as or different from each other),

(in the general formula [B], M represents a transition metal atom of group IV or V in the periodic table;

m represents an integer of from 1 to 4;

R 1 represents a hydrocarbon group having 1 to 8 carbon atoms represented by general formula C n′ H 2n′+1 (n′ is an integer of from 1 to 8);

R 2 to R 5 may be the same as or different from each other, and represent a hydrogen atom, a halogen atom, a hydrocarbon group, a heterocyclic compound residue, an oxygen-containing group, a nitrogen-containing group, a boron-containing group, a sulfur-containing group, a phosphorous-containing group, a silicon-containing group, a germanium-containing group, or a tin-containing group, in which two or more thereof may bond to each other to form a ring;

R 6 to R 8 are hydrocarbon groups, at least one of which is an aromatic hydrocarbon group, and when m is an integer of 2 or larger, two of the groups represented by R 2 to R 8 between structural units of formula [B] may be bonded to each other;

n is a value satisfying a valence of M, and X represents a hydrogen atom, a halogen atom, a hydrocarbon group, an oxygen-containing group, a sulfur-containing group, a nitrogen-containing group, a boron-containing group, an aluminum-containing group, a phosphorous-containing group, a halogen-containing group, a heterocyclic compound residue, a silicon-containing group, a germanium-containing group, or a tin-containing group, in which when n is an integer of from 2 or larger, a plurality of Xs may be the same as or different from each other, and the plurality of groups represented by X may bond to each other to form a ring).

7. The method for producing the olefin-based resin (β) according to claim 6 , wherein the copolymerizing step is a step of copolymerizing by a solution polymerization method in a temperature range of from 80 to 300° C.

8. A molded article comprising the propylene-based resin composition according to claim 1 .