Process for controlling the MWD of a broad/bimodal resin produced in a single reactor

A process for increasing the FI of bimodal molecular weight distribution resin or a broad molecular weight distribution resin of ethylene which comprises a high molecular weight component and a low molecular weight component, by decreasing the relative amount of a high molecular weight component, said process comprising

• contacting a feed comprising ethylene, under ethylene polymerization conditions, with a catalyst comprising a support and two sources of transition metals, wherein the catalyst comprises
• a dry, anhydrous, support containing composition comprising an activated metallocene compound of a transition metal and a non-metallocene transition metal compound,
• wherein the support is the reaction product of
• (1) silica having OH groups, impregnated with RMgR', wherein each of R and R' is an alkyl group of 4 to 10 carbon atoms,
• wherein RMgR' is present in an amount to provide a RMgR':OH molar ratio of 0.5:1 to 4:1;
• and
• (2) an organic alcohol reagent having a formula R"OH, wherein R" is an alkyl group of 1 to 12 carbon atoms;
• wherein said alcohol reagent is used in an amount effective to provide an alcohol/Mg molar ratio of 0.5 to 2.0;
• producing bimodal molecular weight distribution resin or a broad molecular weight distribution resin each of which is further characterized as unmodified;
• introducing additional feed for said contacting with said catalyst;
• adding an amount of a reagent selected from the group consisting of water, carbon dioxide and admixtures thereof,
• wherein the amount of reagent is effective to alter the first productivity relative to the non-metallocene transition metal compound;
• wherein the amount ranges from 0-20 ppm H.sub.2 O based on ethylene;
• 0-10 ppm CO.sub.2 based on ethylene;
• and
• recovering a modified product which has a second relative ratio of said high molecular weight component to said low molecular weight component which second relative ratio is less than the corresponding ratio in said unmodified bimodal molecular weight distribution resin or a broad molecular weight distribution resin.

A process for increasing the FI of bimodal molecular weight distribution resin or a broad molecular weight distribution resin of ethylene which comprises a high molecular weight component and a low molecular weight component, by decreasing the relative amount of said high molecular weight component, said process comprising

• contacting a feed comprising ethylene, under ethylene polymerization conditions, with a catalyst comprising a support and two sources of transition metals, wherein the catalyst comprises
• a dry, anhydrous, support containing composition comprising an activated metallocene compound of a transition metal and a non-metallocene transition metal compound,
• wherein the support is the reaction product of
• (1) silica having OH groups, impregnated with RMgR', wherein each of R and R' is an alkyl group of 4 to 10 carbon atoms,
• wherein RMgR' is present in an amount to provide a RMgR':OH molar ratio of 0.5:1 to 4:1;
• and
• (2) an organic alcohol reagent having a formula R"OH, wherein R" is an alkyl group of 1 to 12 carbon atoms;
• wherein said alcohol reagent is used in an amount effective to provide an alcohol/Mg molar ratio of 0.5 to 2.0;
• producing bimodal molecular weight distribution resin or a broad molecular weight distribution resin unmodified product;
• introducing additional feed for said contacting with said catalyst;
• adding an amount of a reagent selected from the group consisting of water, carbon dioxide and admixtures thereof,
• wherein the amount of reagent ranges from 0.1 to 1000 ppm H.sub.2 O based on ethylene;
• 0.1 to 50 ppm CO.sub.2 based on ethylene;
• and
• recovering a modified product which has an FI that is at least 10 percent higher than that of the unmodified product.