Interpolymers of ethylene and unsaturated carboxylic acids

A process for producing substantially homogeneous, random interpolymers comprising about 99% to about 65% by weight of ethylene monomer with about 1% to about 35% by weight of at least one copolymerizable olefinically-unsaturated comonomer selected from the group comprising an unsaturated carboxylic acid, alkyl acrylates, alkyl methacrylates and vinyl esters, said process comprising interpolymerizing the monomers in a well-stirred autoclave reactor operated in a continuous manner at steady state conditions using a free-radical polymerization initiator under substantially constant conditions of temperature, pressure, and flow rates,

• wherein the conditions of temperature and pressure required to produce operation at the phase boundary are exceeded, respectively, by using a temperature of at least 15.degree. C. above that at the phase boundary and a pressure of more than 2000 psi above that at the phase boundary,
• whereby the molecular weight distribution (MWD) boundary is reached or surpassed,
• thereby producing an interpolymer having less gels and/or grain.

A process for producing homogeneous, random interpolymers comprising about 99% to about 65% by weight of ethylene monomer and about 1% to about 35% by weight of acrylic acid comonomer, said process comprising interpolymerizing the monomers in a substantially constant environment, under steady state conditions, in a single-phase reaction mixture, under the influence of a free-radical initiator, and in a well-stirred autoclave reactor operated in a continuous manner as the monomers are fed into the reactor and the reaction mixture is withdrawn, said process being characterized by

• the use of synthesis conditions of temperature and pressure which are elevated to a level high enough above the phase boundary between two-phase and single-phase operation such that the molecular weight distribution (MWD) boundary is reached, or surpassed, the said molecular weight distribution boundary being the highest ratio of weight average molecular weight/number average molecular weight obtainable in single-phase operation, said elevated pressure being greater than 2000 psi above, and said elevated temperature being greater than 15.degree. C. above, the synthesis conditions required at the phase boundary for a given mixture of ethylene and comonomer, thereby producing an interpolymer having less gels and/or grain.

A process for producing substantially homogeneous, random interpolymers comprising about 99% to about 65% by weight of ethylene monomer with about 1% to aboul 35% by weight of acrylic acid comonomer, said process comprising interpolymerizing the monomers in a well-stirred autoclave reactor operated in a continuous manner at steady state conditions using a free-radical polymerization initiator under substantially constant conditions of temperature, pressure, and flow rates,

• wherein the conditions of temperature and pressure required to produce operation at the phase boundary are exceeded, respectively, by using a temperature of at least 15.degree. C. above that at the phase boundary and a pressure of more than 2000 psi above that at the phase boundary,
• whereby the molecular weight distribution (MWD) boundary is reached or surpassed, thereby producing an interpolymer having less gels and/or grain.

A process for producing homogeneous, random interpolymers comprising about 99% to about 65% by weight of ethylene monomer and about 1% to about 35% by weight of methacrylic acid comonomer, said process comprising interpolymerizing the monomers in a substantially constant environment, under steady state conditions, in a single-phase reaction mixture, under the influence of a free-radical initiator, and in a well-stirred autoclave reactor operated in a continuous manner as the monomers are fed into the reactor and the reaction mixture is withdrawn, said process being characterized by

• the use of synthesis conditions of temperature and pressure which are elevated to a level high enough above the phase boundary between two-phase and single-phase operation such that the molecular weight distribution (MWD) boundary is reached, or surpassed, the said molecular weight distribution boundary being the highest ratio of weight average molecular weight/number average molecular weight obtainable in single-phase operation, said elevated pressure being greater than 2000 psi above, and said elevated temperature being greater than 15.degree. C. above, the synthesis conditions required at the phase boundary for a given mixture of ethylene and comonomer thereby producing an interpolymer having less gels and/or grain.

A process for producing substantially homogeneous, random interpolymers comprising about 99% to about 65% by weight of ethylene monomer with about 1% to about 35% by weight of methacrylic acid comonomer, said process comprising interpolymerizing the monomers in a well-stirred autoclave reactor operated in a continuous manner at steady state conditions using a free-radical polymerization initiator under substantially constant conditions of temperature, pressure, and flow rates,

• wherein the conditions of temperature and pressure required to produce operation at the phase boundary are exceeded, respectively, by using a temperature of at least 15.degree. C. above that at the phase boundary and a pressure of more than 2000 psi above that at the phase boundary,
• whereby the molecular weight distribution (MWD) boundary is reached or surpassed, thereby producing an interpolymer having less gels and/or grain.