Processing

Please wait...

Settings

Settings

Goto Application

1. WO1996039552 - PROCESS AND PRODUCT OF ACRYLONITRILE COPOLYMER

Note: Text based on automatic Optical Character Recognition processes. Please use the PDF version for legal matters

[ EN ]

Claims

1. A process for the precipitation polymerization of acrylonitrile comprising:
maintaining in a reaction zone a substantially metal-ion free solvent system comprising water and an organic solvent capable of dissolving acrylonitrile copolymer,
adding to the reaction zone a vinyl sulfonic acid comonomer-free feedstock comprising a major amount of acrylonitrile monomer and a minor amount of a vinyl carboxylic acid comonomer,
adding to the reaction zone an initiator system comprising a peroxide, a low molecular weight organic mercaptan, and less than 10 ppm of metal ion, and
polymerizing the acrylonitrile monomer and vinyl carboxylic acid monomer under suitable conditions of temperature and pressure to obtain an acrylonitrile copolymer.

2. A process according to claim 1 further comprising:
stripping off water and excess monomer and comonomer to obtain a spinnable solution of acrylonitrile copolymer, and
wet spinning the solution to produce round fibers.

3. A process according to claim 2 further comprising:
adding to the fibers an oxidation catalyst which is member selected from the group consisting of ammonia and low molecular weight amines.

4. A process according to claim 3 wherein the addition of oxidation catalyst is performed prior to wet spinning.

5. A process according to claim 1 wherein the organic solvent capable of dissolving acrylonitrile copolymer is a member selected from the group consisting of dimethylformamide, dimethyl acetamide, dimethyl sulfoxide, tetramethylene cyclic sulfone and butyrolactone.

6. A process according to claim 1 wherein the vinyl carboxylic acid comonomer is a member selected from the group consisting of itaconic acid, acrylic acid and methacrylic acid.

7. A process according to claim 1 wherein the peroxide is a member selected from the group consisting of hydrogen peroxide, t-butyl hydroperoxide, t-butyl peroxide and lauroyl peroxide.

8. A process according to claim 1 wherein the low molecular weight organic mercaptan is a member selected from the group consisting of 1-thioglycerol, mercapto ethanol and butyl mercaptan isomers.

9. An acrylonitrile copolymer prepared according to the process of claim 1.

10. A process for preparing acrylonitrile fibers comprising:
maintaining in a reaction zone a solvent system consisting essentially of water and a co- solvent which is a member selected from the group consisting of sodium thiocyanate and zinc chloride,
adding to the reaction zone a vinyl sulfonic acid comonomer-free feedstock comprising a major amount of acrylonitrile monomer and a minor amount of a vinyl carboxylic acid comonomer,
adding to the reaction zone an initiator system comprising a peroxide, a low molecular weight organic mercaptan and a catalytic amount of metal ion,
polymerizing the acrylonitrile monomer and vinyl carboxylic acid monomer under suitable precipitation polymerization conditions of temperature and pressure to obtain an acrylonitrile copolymer,
stripping of water and excess monomer and comonomer to obtain a spinnable solution of acrylonitrile copolymer, and
wet spinning the solution to produce round fibers.

11. A process according to claim 10 further comprising adding to the fibers an oxidation catalyst which is a member selected from the group consisting of ammonia and low molecular weight amines.

12. A process according to claim 11 wherein the addition of oxidation catalyst is performed prior to wet spinning.

13. An acrylonitrile copolymer fiber prepared according to the process of claim 10.

14. A process for the preparation of an acrylonitrile copolymer comprising:
maintaining in a reaction zone a solvent system consisting essentially of water and a co-solvent which is a member selected from the group consisting of sodium thiocyanate and zinc chloride,
adding to the reaction zone a vinyl sulfonic acid comonomer-free feedstock comprising a major amount of acrylonitrile monomer and a minor amount of a vinyl carboxylic acid comonomer,
adding to the reaction zone an initiator system comprising a peroxide, a low molecular weight organic mercaptan and a catalytic amount of metal ion, and
polymerizing the acrylonitrile monomer and vinyl carboxylic acid monomer under suitable precipitation polymerization conditions of temperature and pressure to obtain an acrylonitrile copolymer.