Adhesive composition including ethylene/alpha-olefin copolymer

A method of preparing an ethylene/alpha-olefin copolymer, which satisfies the following conditions i) to iv):

• i) a viscosity:
• 6,000 cP to 40,000 cP, when measured at a temperature of 180° C.,
• ii) a molecular weight distribution (MWD):
• 1.5 to 3.0,
• iii) a total number of unsaturated functional groups per 1000 carbon atoms:
• 0.8 or less, and
• iv) a Rvd value according to the following Mathematical Equation 1:
• 0.3 or less:
• R
• vd
• =
• [
• vinylidene
• ]
• [
• vinyl
• ]
• +
• [
• vinylene
• ]
• +
• [
• vinylidene
• ]
• [
• Mathematical
• ⁢
• Equation
• ⁢
• 1
• ]
• in Mathematical Equation 1, the vinyl, vinylene and vinylidene mean the number of each functional group per 1000 carbon atoms, measured through nuclear magnetic spectroscopic analysis,
• the method comprising a step of polymerizing ethylene and an alpha-olefin-based monomer by injecting hydrogen in 45 to 100 cc/min in the presence of a catalyst composition including a transition metal compound of Formula 1:
• wherein,
• R1 is hydrogen;
• alkyl of 1 to 20 carbon atoms;
• cycloalkyl of 3 to 20 carbon atoms;
• alkenyl of 2 to 20 carbon atoms;
• alkoxy of 1 to 20 carbon atoms;
• aryl of 6 to 20 carbon atoms;
• arylalkoxy of 7 to 20 carbon atoms;
• alkylaryl of 7 to 20 carbon atoms;
• or arylalkyl of 7 to 20 carbon atoms,
• R2a to R2e are each independently hydrogen;
• halogen;
• alkyl of 1 to 20 carbon atoms;
• cycloalkyl of 3 to 20 carbon atoms;
• alkenyl of 2 to 20 carbon atoms;
• alkoxy of 1 to 20 carbon atoms;
• or aryl of 6 to 20 carbon atoms,
• R3 is hydrogen;
• halogen;
• alkyl of 1 to 20 carbon atoms;
• cycloalkyl of 3 to 20 carbon atoms;
• alkenyl of 2 to 20 carbon atoms;
• aryl of 6 to 20 carbon atoms;
• alkylaryl of 6 to 20 carbon atoms;
• arylalkyl of 7 to 20 carbon atoms;
• alkyl amido of 1 to 20 carbon atoms;
• aryl amido of 6 to 20 carbon atoms;
• or phenyl which is substituted with one or more selected from the group consisting of halogen, alkyl of 1 to 20 carbon atoms, cycloalkyl of 3 to 20 carbon atoms, alkenyl of 2 to 20 carbon atoms, alkoxy of 1 to 20 carbon atoms and aryl of 6 to 20 carbon atoms,
• R4 to R9 are each independently hydrogen;
• silyl;
• alkyl of 1 to 20 carbon atoms;
• cycloalkyl of 3 to 20 carbon atoms;
• alkenyl of 2 to 20 carbon atoms;
• aryl of 6 to 20 carbon atoms;
• alkylaryl of 7 to 20 carbon atoms;
• arylalkyl of 7 to 20 carbon atoms;
• or a metalloid radical of a metal in group 14, which is substituted with hydrocarbyl of 1 to 20 carbon atoms;
• where among the R6 to R9, adjacent two or more are optionally connected with each other to form a ring,
• Q is Si or C,
• M is a transition metal in group 4, and
• X1 and X2 are each independently hydrogen;
• halogen;
• alkyl of 1 to 20 carbon atoms;
• cycloalkyl of 3 to 20 carbon atoms;
• alkenyl of 2 to 20 carbon atoms;
• aryl of 6 to 20 carbon atoms;
• alkylaryl of 7 to 20 carbon atoms;
• arylalkyl of 7 to 20 carbon atoms;
• alkylamino of 1 to 20 carbon atoms;
• or arylamino of 6 to 20 carbon atoms.