Method to improve the optical properties of ethylene copolymer compositions

A method for improving the optical properties of an ethylene copolymer composition comprising a first ethylene copolymer, a second ethylene copolymer and optionally a third ethylene copolymer, wherein the ethylene copolymer composition is made in a solution phase polymerization process;

• the solution phase polymerization process comprising:
• polymerizing ethylene and an alpha-olefin in a first reactor with a single site catalyst to give a first ethylene copolymer;
• polymerizing ethylene and an alpha-olefin in a second reactor with a multi-site catalyst to give a second ethylene copolymer;
• optionally polymerizing ethylene and an alpha-olefin in a third reactor with a single site catalyst or a multi-site catalyst to give a third ethylene copolymer;
• wherein the first, second and optional third reactor are configured in series with one another;
• the method comprising:
• decreasing the alpha-olefin ratio split from a first higher value to a second lower value, wherein the alpha-olefin ratio split is defined by the equation:
• F
• ⁢
• 1
• α
• -
• olefin
• ×
• F
• ⁢
• 2
• ethylene
• /
• (
• F
• ⁢
• 1
• α
• -
• olefin
• ×
• F
• ⁢
• 2
• ethylene
• +
• F
• ⁢
• 2
• α
• -
• olefin
• ×
• F
• ⁢
• 1
• ethylene
• )
• ;
• where F1α-olefin is the flow rate (in kg/hour) of alpha-olefin to the first reactor;
• F1ethylene is the flow rate (in kg/hour) of ethylene to the first reactor;
• F2α-olefin is the flow rate (in kg/hour) of alpha-olefin to the second reactor;
• and F2ethylene is the flow rate (in kg/hour) of ethylene to the second reactor;
• and
• wherein the improvement of the optical properties of the ethylene copolymer composition is indicated by one or both of:
• a decrease in optical haze of a monolayer blown film which is made from the ethylene copolymer composition;
• an increase in gloss at 450 of a monolayer blown film which is made from the ethylene copolymer composition.