Process for increasing the relative viscosity of polycaprolactam with phosphite compound

Claim 2

A process for decreasing the melt index and increasing the viscosity of polymers of caprolactam that comprises: (a) forming a mixture of one or more of said polymers and an effective amount of one or more phosphite compounds of the formula: ##STR6## wherein: R 1 is alkyl or haloalkyl having from 2 to 12 carbon atoms or phenyl either unsubstituted or substituted with one or more halo or alkyl substituents having 1 to 12 carbon atoms; R 2 and R 3 are individually R 1 , hydrogen or a metal cation; and (b) heating said mixture for a period of time between about 1 minute and about 15 minutes at a temperature between about the melting point of said polymer and about 320° C. to produce a polymer having increased relative viscosity; wherein said relative viscosity of said polymer of caprolactam is increased by at least about 20%.

Claim 3

A process according to claim 1 wherein said time is between about 2 minutes and about 12 minutes, and said temperature is between about 275° C. and about 310° C.

Claim 4

A process according to claim 1 wherein R 1 , R 2 and R 3 are the same and are alkyl having from 2 to 12 carbon atoms.

Claim 5

A process according to claim 3 wherein R 1 , R 2 and R 3 are n-butyl.

Claim 6

A process according to claim 3 wherein R 1 , R 2 and R 3 are ethyl.

Claim 7

A process according to claim 1 wherein R 1 , R 2 and R 3 are the same and are phenyl or phenyl substituted with at least one alkyl moiety having 1 to 12 carbon atoms.

Claim 8

A process according to claim 6 wherein R 1 , R 2 and R 3 are phenyl.

Claim 9

A process according to claim 6 wherein R 1 , R 2 and R 3 are selected from the group consisting of di-t-butylphenyl and nonylphenyl.

Claim 10

A process according to claim 1 wherein less than about 80% of the terminal groups of said polymers are carboxyl function based on the total number of terminal groups and the remainder of said groups are amino functions.

Claim 11

A process according to claim 9 wherein from about 35 to about 65 percent of said terminal groups are carboxyl functions and the remainder of said groups are amino functions.

Claim 12

A process according to claim 1 wherein said molten mixture contains from about 0.05 to about 2 weight percent of said phosphite compounds based on the total weight of said mixture.

Claim 13

A process according to claim 11 wherein said weight percent of said phosphite compounds is from about 0.1 to about 0.6.

Claim 14

A process according to claim 1 which comprises the additional step of adding to said mixture one or more optional components selected from the group consisting of fillers, plasticizers, colorants, fire retardants, mold release agents, antioxidants, antistatic agents, and ultraviolet light stabilizers.

Claim 15

A process for decreasing the melt index and increasing the viscosity of polymers of caprolactam that comprises: (a) forming a mixture of one or more of said polymers and an effective amount of one or more phosphite compounds of the formula: ##STR7## wherein: R 4 is alkyl or haloalkyl having from 2 to 12 carbon atoms or phenyl either unsubstituted or substituted with one or more halo or alkyl substituents having 1 to 12 carbon atoms; R 5 , R 6 and R 7 are individually R 4 , hydrogen or a metal cation; and (b) heating said mixture for a period of time between about 1 minute and about 15 minutes at a temperature between about the melting point of said polymer and about 320° C. to produce a polymer having increased relative viscosity; wherein said relative viscosity of said polymer of caprolactam is increased by at least about 20%.

Claim 16

A process for decreasing the melt index and increasing the viscosity of polymers of caprolactam that comprises: (a) forming a mixture of one or more of said polymers and an effective amount of one or more phosphite compounds of the formula: ##STR7## wherein: R 4 is alkyl or haloalkyl having from 2 to 12 carbon atoms or phenyl either unsubstituted or substituted with one or more halo or alkyl substituents having 1 to 12 carbon atoms; R 5 , R 6 and R 7 are individually R 4 , hydrogen or a metal cation; and (b) heating said mixture for a period of time between about 1 minute and about 15 minutes at a temperature between about the melting point of said polymer and about 320° C. to produce a polymer having increased relative viscosity; wherein said relative viscosity of said polymer of caprolactam is increased by at least about 20%.

Claim 17

A process according to claim 4 wherein R 4 , R 5 , R 6 and R 7 are di-t-butylphenyl.

Claim 18

A process according to claim 3 wherein R 1 , R 2 , and R 3 are the same and are nonylphenyl.