US4036802A — Tetrafluoroethylene copolymer fine powder resin

Claim 1

Independent Claim 307 words

An aqueous polymer dispersion comprising a dispersion of non-melt-fabricable tetrafluoroethylene polymer particles in water at a solids content of between about 10 and about 65 weight percent; said particles having an average size of between about 0.1 and 0.5μ; said particles having at least two portions, an outer portion and an adjacent inner portion, each portion consisting essentially of a copolymer of units of tetrafluoroethylene and at least one comonomer having the formula ##STR11## wherein R 1 independently if F or H; R 2 independently is F or Cl; R 3 can be Cl, --R F , --OR F ,--R' F H, --OR' F H, --R' F Cl, --OR' F Cl, or ##STR12## Wherein R F is linear perfluoroalkyl of 1-5 carbon atoms, and R' F is linear perfluoroalkylene (perfluorinated alkane diradical) of 1-5 carbon atoms in which the designated substituent is an omega substituent; and when R 2 is F, R 1 and R 3 taken together can be ##STR13## or the formula ##STR14## wherein R 5 and R 6 are independently --CF 3 or --CClF 2 ; said inner copolymer portion containing a higher percentage of said comonomer than the outer copolymer portion; the total comonomer content present in the particle, the amount of comonomer present in the copolymer of each portion, and the amount of each portion within such particles being sufficient to produce on AWG 22 wire a sintered coating having no more than 5 flaws per 100 meters of coated wire when said particles are paste extruded at a reduction ratio of 2840:1, the flaws being detected by subjecting the sintered coated wire to a high voltage spark tester at 2KV and 3000Hz; the copolymers of the inner portion and the outer portion combined containing an amount of comonomer which is low enough to maintain the non-melt-fabricable nature of the polymer particles.

Claim 2

Dependent Claim 307 words

An aqueous polymer dispersion comprising a dispersion of non-melt-fabricable tetrafluoroethylene polymer particles in water at a solids content of between about 10 and about 65 weight percent; said particles having an average size of between about 0.1 and 0.5μ; said particles having at least two portions, an outer portion and an adjacent inner portion, each portion consisting essentially of a copolymer of units of tetrafluoroethylene and at least one comonomer having the formula ##STR11## wherein R 1 independently if F or H; R 2 independently is F or Cl; R 3 can be Cl, --R F , --OR F ,--R' F H, --OR' F H, --R' F Cl, --OR' F Cl, or ##STR12## Wherein R F is linear perfluoroalkyl of 1-5 carbon atoms, and R' F is linear perfluoroalkylene (perfluorinated alkane diradical) of 1-5 carbon atoms in which the designated substituent is an omega substituent; and when R 2 is F, R 1 and R 3 taken together can be ##STR13## or the formula ##STR14## wherein R 5 and R 6 are independently --CF 3 or --CClF 2 ; said inner copolymer portion containing a higher percentage of said comonomer than the outer copolymer portion; the total comonomer content present in the particle, the amount of comonomer present in the copolymer of each portion, and the amount of each portion within such particles being sufficient to produce on AWG 22 wire a sintered coating having no more than 5 flaws per 100 meters of coated wire when said particles are paste extruded at a reduction ratio of 2840:1, the flaws being detected by subjecting the sintered coated wire to a high voltage spark tester at 2KV and 3000Hz; the copolymers of the inner portion and the outer portion combined containing an amount of comonomer which is low enough to maintain the non-melt-fabricable nature of the polymer particles.

Claim 3

Dependent Claim 16 words

The aqueous polymer dispersion of claim 1 wherein the comonomer is F 2 C=CFCF 3 .

Claim 4

Dependent Claim 16 words

The aqueous polymer dispersion of claim 1 wherein the comonomer is F 2 C=CFOR F .

Claim 5

Dependent Claim 14 words

The aqueous polymer dispersion of claim 1 wherein the comonomer is F 2 C=CFCl.

Claim 6

Dependent Claim 37 words

The aqueous polymer dispersion of claim 2 wherein the copolymers of the inner portion and the outer portion combined contain between about 0.005 and about 2.0 weight percent comonomer units based on total weight of said particles.

Claim 7

Dependent Claim 37 words

The aqueous polymer dispersion of claim 1 wherein the tetrafluoroethylene in polymerized form in the inner portion comprises between about 25% and 85% by weight of the total tetrafluoroethylene polymerized in the inner and the outer portions.

Claim 8

Dependent Claim 28 words

The aqueous polymer dispersion of claim 1 wherein said particles contain a core of polytetrafluoroethylene of up to 15% by weight based on the weight of the particle.

Claim 9

Dependent Claim 16 words

The aqueous polymer dispersion of claim 7 wherein the comonomer is F 2 C=CFCF 3 .

Claim 10

Dependent Claim 16 words

The aqueous polymer dispersion of claim 8 wherein the comonomer is F 2 C=CFOR F .

Claim 11

Dependent Claim 14 words

The aqueous polymer dispersion of claim 8 wherein the comonomer is F 2 C=CFCl.

Claim 12

Dependent Claim 36 words

An agglomerated fine powder resin whose agglomerated particles have an average size of between about 350μ and 800μ and are composed of primary particles defined as provided in the definition of the particles in claim 1.

Claim 13

Dependent Claim 37 words

An agglomerated tetrafluoroethylene fine powder resin whose agglomerated particles have an average size of between about 350μ and 800μ and are composed of primary particles defined as provided in the definition of the particles of claim 2.

Claim 14

Dependent Claim 37 words

An agglomerated tetrafluoroethylene fine powder resin whose agglomerated particles have an average size of between about 350μ and 800μ and are composed of primary particles defined as provided in the definition of the particles in claim 3.

Claim 15

Dependent Claim 37 words

An agglomerated tetrafluoroethylene fine powder resin whose agglomerated particles have an average size of between about 350μ and 800μ and are composed of primary particles defined as provided in the definition of the particles in claim 4.

Claim 16

Dependent Claim 37 words

An agglomerated tetrafluoroethylene fine powder resin whose agglomerated particles have an average size of between about 350μ and 800μ and are composed of primary particles defined as provided in the definition of the particles in claim 5.

Claim 17

Dependent Claim 203 words

A process for preparing an aqueous dispersion of tetrafluoroethylene polymer particles which comprises 1. subjecting tetrafluoroethylene and at least one comonomer of the formula ##STR15## wherein R 1 independently is F or H; R 2 independently is F or Cl; R 3 can be Cl, --R F , --OR F , --R' F H, --OR' F H, --R' F Cl, --OR' F Cl, or ##STR16## wherein R F is linear perfluoroalkyl of 1-5 carbon atoms, and R' F is linear perfluoroalkylene (perfluorinated alkane diradical) of 1-5 carbon atoms in which the designated substituent is an omega substituent; and when R 2 is F, R 1 and R 3 taken together can be ##STR17## or the formula ##STR18## wherein R 5 and R 6 independently are --CF 3 or --CCLF 2 ; wherein the mole ratio of the amount of the comonomer to the tetrafluoroethylene is between about 0.0005 and about 0.05, to polymerizing conditions to temperature and pressure in an aqueous medium having dissolved therein a free-radical initiator and a dispersing agent and at an agitation level of from between about 2 to 12 joules/sec.-1. until the polymer solids content is between about 20 and 50% of the weight of the resulting dispersion;

Claim 18

Dependent Claim 203 words

A process for preparing an aqueous dispersion of tetrafluoroethylene polymer particles which comprises 1. subjecting tetrafluoroethylene and at least one comonomer of the formula ##STR15## wherein R 1 independently is F or H; R 2 independently is F or Cl; R 3 can be Cl, --R F , --OR F , --R' F H, --OR' F H, --R' F Cl, --OR' F Cl, or ##STR16## wherein R F is linear perfluoroalkyl of 1-5 carbon atoms, and R' F is linear perfluoroalkylene (perfluorinated alkane diradical) of 1-5 carbon atoms in which the designated substituent is an omega substituent; and when R 2 is F, R 1 and R 3 taken together can be ##STR17## or the formula ##STR18## wherein R 5 and R 6 independently are --CF 3 or --CCLF 2 ; wherein the mole ratio of the amount of the comonomer to the tetrafluoroethylene is between about 0.0005 and about 0.05, to polymerizing conditions to temperature and pressure in an aqueous medium having dissolved therein a free-radical initiator and a dispersing agent and at an agitation level of from between about 2 to 12 joules/sec.-1. until the polymer solids content is between about 20 and 50% of the weight of the resulting dispersion;

Claim 19

Dependent Claim 92 words

subjecting the aqueous dispersion obtained in step (1) to tetrafluoroethylene and said comonomer in a mole ratio of comonomer to tetrafluoroetylene of between about 0.0001 and 0.005, provided said ratio is less than that in step (1) under polymerizing conditions of temperature and pressure and at an agitation level of from between about 2 to 12 joules/sec.-1. until the solids content is between about 35 and 65% of the weight of the resulting dispersion and is at least about 15% greater than the solids content of the dispersion obtained in step (1).

Claim 20

Dependent Claim 92 words

subjecting the aqueous dispersion obtained in step (1) to tetrafluoroethylene and said comonomer in a mole ratio of comonomer to tetrafluoroetylene of between about 0.0001 and 0.005, provided said ratio is less than that in step (1) under polymerizing conditions of temperature and pressure and at an agitation level of from between about 2 to 12 joules/sec.-1. until the solids content is between about 35 and 65% of the weight of the resulting dispersion and is at least about 15% greater than the solids content of the dispersion obtained in step (1).

Claim 21

Dependent Claim 14 words

The process of claim 16 wherein the comonomer is F 2 C=CFCF 3 .

Claim 22

Dependent Claim 14 words

The process of claim 16 wherein the comonomer is F 2 C=CFOR F .

Claim 23

Dependent Claim 12 words

The process of claim 16 wherein the comonomer is F 2 C=CFCl.

Claim 24

Dependent Claim 27 words

The process of claim 16 wherein step (1) is carried out in the presence of particles of between 0.03 and 0.12μ of polytetrafluoroethylene in said aqueous medium.

Claim 25

Dependent Claim 22 words

The process of claim 16 wherein in step (2) the mole ratio of comonomer to tetrafluoroethylene is between about 0.0002 and 0.005.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1980-07-18	1981-01-17	1981-07-19	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	1984-07-18	1985-01-17	1985-07-19	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	1988-07-18	1989-01-17	1989-07-19	$7700.00	Window Closed / Lapsed

Tetrafluoroethylene copolymer fine powder resin

Abstract

Inventors

Bibliographic Details

Claims Analysis

References Cited (Backward Citations)

USPTO Annuity & Maintenance Windows

Assigned Categories & Tags

Assign Category Tag