Process for producing homogeneous modified copolymers of ethylene/alpha-olefin carboxylic acids or esters

Claim 2

A process for producing high molecular weight, modified, homogeneous, random interpolymers having melt flow rates in the range of about 0.1 to about 300 g/10 min., as determined by ASTM D-1238 (190° C./2160 g) and reduced long chain branching, comprising about 99% to about 65% by weight of ethylene monomer and about 1% to about 35% by weight of at least one olefinically unsaturated comonomer selected from the group consisting of unsaturated carboxylic acids, alkyl acrylates and alkyl methacrylates, said process comprising interpolymerizing the monomers in a substantially constant environment, under steady state conditions, in a single-phase reaction mixture, in the presence of minor amounts of one or more telogenic modifiers, under the influence of a free-radical initiator, and in a well-stirred autoclave reactor operated in a continuous manner and at an unreacted gas recycle rate sufficient to produce said high molecular weight interpolymers as the monomers, telogenic modifier(s), and initiator are fed into the reactor and the reaction mixture is withdrawn, said process being characterized by the use of synthesis conditions of temperature and pressure which are elevated to a level above the phase boundary between two-phase and single-phase operation and further characterized by the use of either, or both of, (a) a temperature which is lower than, or (b) a pressure which is higher than that which would be required without the presence of the modifier, said process further characterized by controlling said minor amounts of said one or more telogenic modifiers and said high molecular weight of said interpolymers by controlling said telogenic modifier(s) feed rate, or unreacted gas recycle rate, or both.

Claim 3

The process of claim 1 wherein the olefinically-unsaturated comonomer comprises acrylic acid or methacrylic acid.

Claim 4

The process of claim 1 wherein the olefinically-unsaturated comonomer is acrylic acid.

Claim 5

The process of claim 1 wherein the olefinically-unsaturated comonomer is methacrylic acid.

Claim 6

The process of claim 1 wherein the so-produced interpolymers comprise from about 99% to about 88% by weight of ethylene units in the polymer chain, the remaining percentage comprising acrylic acid units, except for the terminal telogen groups on the polymer chains.

Claim 7

The process of claim 1 wherein the so-produced interpolymers comprise from about 99% to about 88% by weight of ethylene units in the polymer chain.

Claim 8

The process of claim 1 wherein the modifier or modifiers comprise at least one of alkanes, alkenes, alcohols, ketones, hydrogen, silanes, cyclic hydrocarbons, aromatic hydrocarbons, halogenated hydrocarbons, sulfoxides, ethers, esters, amines, amides, nitriles, anhydrides, furans, aldehydes, cyanates, or sulfides at concentrations from about 0.0001% to about 10% by weight.

Claim 9

The process of claim 1 wherein the modifier or modifiers comprises an alkane.

Claim 10

The process of claim 1 wherein the modifier or modifiers comprises an alcohol.

Claim 11

The process of claim 1 wherein the modifier is isobutane.

Claim 12

The process of claim 1 wherein the modifier is methanol.

Claim 13

The process of claim 1 wherein the synthesis conditions comprise an elevated temperature which is in the range of about 150° C. to about 350° C. and an elevated pressure which is in the range of about 18,000 to about 50,000 psi., wherein said pressure is at least 1 psi. above, and said temperature is at least 1 degree above the minimum amount needed to produce a single-phase reaction mixture and in the presence of sufficient modifier such that either, or both, of (a) the pressure is above or (b) the temperature is below that typically required to produce a single-phase reaction mixture without the modifier.

Claim 14

A process for producing substantially homogeneous, high molecular weight random interpolymers having melt flow rates in the range of about 0.1 to about 300 g/10 minutes, as determined by ASTM D-1238 (190° C./2160 g) a narrow molecular weight distribution and/or less high molecular weight polymer fractions and reduced long chain branching, 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 consisting of an unsaturated carboxylic acids, alkyl acrylates and alkyl methacrylates, said process comprising interpolymerizing the monomers in a well-stirred autoclave reactor operated in a continuous manner and at an unreacted gas recycle rate sufficient to produce said high molecular weight interpolymers 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 while reacting in the presence of one or more polymerization modifiers selected from the group consisting of alkanes, alkenes, alcohols, ketones, hydrogen, silanes, cyclic hydrocarbons, aromatic hydrocarbons, halogenated hydrocarbons, sulfoxides, ethers, esteres, amines, amides, nitriles, anhydriedes, furans, aldehydes, cyanates, or sulfides, at concentrations from about 0.0001 weight % to about 10 weight % thereby producing an interpolymer having less long chain branching and wherein the conditions of flow rates of the polymerization modifiers(s) are controlled to control said molecular weights of said interpolymers.

Claim 15

A process for producing substantially homogeneous, high molecular weight random interpolymers having melt flow rates in the range of about 0.1 to about 300 g/10 minutes, as determined by ASTM D-1238 (190° C./2160 g) a narrow molecular weight distribution and/or less high molecular weight polymer fractions and reduced long chain branching, 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 consisting of an unsaturated carboxylic acids, alkyl acrylates and alkyl methacrylates, said process comprising interpolymerizing the monomers in a well-stirred autoclave reactor operated in a continuous manner and at an unreacted gas recycle rate sufficient to produce said high molecular weight interpolymers 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 while reacting in the presence of one or more polymerization modifiers selected from the group consisting of alkanes, alkenes, alcohols, ketones, hydrogen, silanes, cyclic hydrocarbons, aromatic hydrocarbons, halogenated hydrocarbons, sulfoxides, ethers, esteres, amines, amides, nitriles, anhydriedes, furans, aldehydes, cyanates, or sulfides, at concentrations from about 0.0001 weight % to about 10 weight % thereby producing an interpolymer having less long chain branching and wherein the conditions of flow rates of the polymerization modifiers(s) are controlled to control said molecular weights of said interpolymers.

Claim 16

The process of claim 13 wherein the copolymerizable olefinically-unsaturated comonomer comprises an unsaturated carboxylic acid.

Claim 17

The process of claim 13 wherein the copolymerizable olefinically-unsaturated comonomer comprises acrylic acid or methacrylic acid.

Claim 18

The process of claim 13 wherein the copolymerizable olefinically-unsaturated comonomer is acrylic acid.

Claim 19

The process of claim 13 wherein the copolymerizable olefinically-unsaturated comonomer is methacrylic acid.

Claim 20

The process of claim 13 wherein the modifier comprises one or more alkanes.

Claim 21

The process of claim 13 wherein the modifier comprises an alcohol.

Claim 22

The process of claim 13 wherein the modifier is isobutane.

Claim 23

The process of claim 13 wherein the modifier is methanol.