Preparation of ultra-high moleclar weight polyester

Claim 2

A process for preparing porous pills which can be solid state polymerized at a very rapid rate into high molecular weight polyester resin which comprises: (1) dissolving a polyester prepolymer in a suitable organic solvent: (2) recovering the polyester prepolymer from the organic solvent to produce a porous, fibrous mass of the polyester prepolymer; and (3) compacting the porous, fibrous mass into the porous pills.

Claim 3

A process as specified in claim 1 wherein the polyester prepolymer has an intrinsic viscosity which is within the range of about 0.3 to about 2.0 dl/g.

Claim 4

A process as specified in claim 1 wherein the polyester prepolymer is recovered from the organic solvent in the form of a porous, fibrous mass by coagulation.

Claim 5

A process as specified in claim 1 wherein the polyester prepolymer is polyethylene terephthalate.

Claim 6

A process as specified in claim 1 wherein the polyester prepolymer is polyethylene naphthalate.

Claim 7

A process as specified in claim 1 wherein said polyester prepolymer is comprised of repeat units which PG,29 are derived from a diacid component and a diol component: wherein said diacid component is at least one member selected from the group consisting of alkyl dicarboxylic acids which contain from 4 to 36 carbon atoms, diesters of alkyl dicarboxylic acids which contain from 6 to 38 carbon atoms, aryl dicarboxylic acids which contain from 8 to 20 carbon atoms, diesters of aryl dicarboxylic acids which contain from 10 to 22 carbon atoms, alkyl substituted aryl dicarboxylic acids which contain from 9 to 22 carbon atoms, or diesters of alkyl substituted aryl dicarboxylic acids which contain from 11 to 22 carbon atoms and wherein said diol component is at least one member selected from the group consisting of glycols containing from 2 to 12 carbon atoms, glycol ethers containing from 4 to 12 carbon atoms, and polyether glycols having the structural formula HO-(A--O)- n -H wherein A is an alkylene group containing from 2 to 6 carbon atoms and wherein n is an integer from 2 to 400.

Claim 8

A process as specified in claim 6 wherein the polyester prepolymer has an intrinsic viscosity of at least about 0.2 dl/g.

Claim 9

A process as specified in claim 4 wherein the polyester prepolymer has an intrinsic viscosity which is within the range of about 0.3 to 2.0 dl/g.

Claim 10

A process as specified in claim 8 wherein the organic solvent is a trifluoroacetic acid/methylene chloride mixed solvent system.

Claim 11

A process as specified in claim 9 wherein the coagulation is done by utilizing a member selected from the group consisting of alcohols and ketones.

Claim 12

A process as specified in claim 9 wherein the organic solvent is comprised of from about 25 to about 75 weight percent trifluoroacetic acid and from about 25 to about 75 weight percent methylene chloride.

Claim 13

A process as specified in claim 11 wherein the coagulation is done by utilizing an alcohol.

Claim 14

A process as specified in claim 12 wherein the alcohol is methanol.

Claim 15

A process as specified in claim 4 wherein the polyester prepolymer has an intrinsic viscosity which is within the range of about 0.4 to about 0.6 dl/g.

Claim 16

A process as specified in claim 9 wherein the organic solvent is comprised of from about 40 to about 60 weight percent trifluoroacetic acid and from about 40 to about 60 weight percent methylene chloride.

Claim 17

A process as specified in claim 4 wherein the organic solvent is a member selected from the group consisting of nitro-benzene, acetonapthone, hexafluoroacetone, hexafluoroisopropanol, meta-cresol, trifluoroacetic acid/methylene chloride mixed solvent systems, nitro-benzene/tetrachloroethane mixed solvent systems, hexafluoroisopropanol/chloroform mixed solvent systems, and tetrachloroethane/phenol mixed solvent systems.

Claim 18

A process as specified in claim 12 wherein the alcohol is a member selected from the group consisting of methanol, ethanol, isopropyl alcohol, cyclohexanol, n-butyl alcohol, isobutyl alcohol, s-butyl alcohol, and t-butyl alcohol.

Claim 19

A process as specified in claim 4 wherein the porous, fibrous mass is compacted into the porous pills at a temperature which is within the range of about 10° C. to about 50° C.

Claim 20

A process as specified in claim 18 wherein the porous, fibrous mass is compacted into the porous pills at a pressure which is within the range of about 1 ton per square inch to about 40 tons per square inch.