Process of free-radical polymerization in aqueous disperasion for the preparation of polymers
Process of free-radical polymerization in aqueous dispersion for the preparation of polymers, employing (A) at least one ethylenically unsaturated monomer, one of which is employed as the principal monomer and is selected from styrene and its derivatives, acrylic acid and its derivatives, methacrylic acid and its derivatives, dienes, vinyl esters, vinyl ethers, vinylic pyridine derivatives, vinylsulphonic acid and its derivatives, vinylphosphonic acid and its derivatives, and N-vinyl monomers, (B) at least one free-radical initiator selected from diazo compounds, peroxides and dialkyldiphenylalkanes, (C) molecular iodine, and (D) at least one oxidizing agent whose solubility in water is at least 10 g/l, of which at least one may be the one (B); said process comprising the steps whereby (1) at least one fraction of each of compounds (A), (B), (C) and (D) is introduced into a reactor, and (2) the contents of the reactor are reacted while introducing into the reactor the remainder, where appropriate, of each of compounds (A), (B), (C) and (D). Process of free-radical polymerization in aqueous dispersion for the preparation of block copolymers starting from polymers prepared by the abovementioned process.
1 . Process of free-radical polymerization in aqueous dispersion for the preparation of polymers, employing
(A) at least one ethylenically unsaturated monomer, one of which is employed as the principal monomer and is chosen from styrene and its derivatives, acrylic acid and its derivatives, methacrylic acid and its derivatives, dienes, vinyl esters, vinyl ethers, vinyl pyridine derivatives, vinylsulphonic acid and its derivatives, vinylphosphonic acid and its derivatives, and N-vinyl monomers,
(B) at least one free-radical initiator chosen from diazo compounds, peroxides and dialkyldiphenylalkanes,
(C) molecular iodine, and
(D) at least one oxidizing agent whose solubility in water is at least 10 g/l, of which at least one may be the one of (B);
said process comprising the steps whereby
(1 ) at least one fraction of each of compounds (A), (B), (C) and (D) is introduced into a reactor, and
(2) the contents of the reactor are reacted while introducing into the reactor the remainder, where appropriate, of each of compounds (A), (B), (C) and (D).
2 . Process according to claim 1 , characterized in that it is a polymerization process in aqueous suspension, employing, in addition to (A) and (C),
(B) at least one oil-soluble free-radical initiator chosen from oil-soluble diazo compounds, and oil-soluble peroxides, and
(D) at least one oxidizing agent whose solubility in water is at least 10 g/l, of which none is the one of (B).
3 . Process according to claim 1 , characterized in that it is a polymerization process in aqueous emulsion employing, in addition to (A) and (C),
(B) at least one water-soluble free-radical initiator chosen from water-soluble diazo compounds and water-soluble peroxides, and
(D) at least one oxidizing agent whose solubility in water is at least 10 g/l, of which at least one may be the one of (B).
4 . Process according to claim 3 , characterized in that it employs
(B) at least one water-soluble free-radical initiator chosen from water-soluble diazo compounds and water-soluble peroxides, and
(D) one oxidizing agent whose solubility in water is at least 10 g/l, which is the one of (B).
5 . Process according to claim 4 , characterized in that it employs
(B) one water-soluble free-radical initiator chosen from water-soluble diazo compounds and water-soluble peroxides, and
(D) one oxidizing agent whose solubility in water is at least 10 g/l, which is (B).
6 . Process according to claim 4 , characterized in that it employs
(B) two water-soluble free-radical initiators chosen from water-soluble diazo compounds and water-soluble peroxides, and
(D) one oxidizing agent whose solubility in water is at least 10 g/l, which is the one of (B).
7 . Process according to claim 3 , characterized in that it employs
(B) at least one water-soluble free-radical initiator chosen from water-soluble diazo compounds and water-soluble peroxides, and
(D) two oxidizing agents whose solubility in water is at least 10 g/l, each one being the one of (B).
8 . Process according to claim 3 , characterized in that it employs
(B) at least one water-soluble free-radical initiator chosen from water-soluble diazo compounds and water-soluble peroxides, and
(D) one oxidizing agent whose solubility in water is at least 10 g/l, which is not the one of (B).
9 . Process according to claim 1 , characterized in that it is a process of polymerization in aqueous mini-emulsion employing, in addition to (A) and (C),
(B) at least one oil-soluble free-radical initiator chosen from oil-soluble diazo compounds and oil-soluble peroxides and/or at least one water-soluble free-radical initiator, chosen from water-soluble diazo compounds and water-soluble peroxides, and
(D) at least one oxidizing agent whose solubility in water is at least 10 g/l, of which at least one may be the one of (B).
10 . Process of free-radical polymerization in aqueous dispersion for the preparation of block copolymers, employing
(A′) At least one ethylenically unsaturated monomer chosen from styrene and its derivatives, acrylic acid and its derivatives, methacrylic acid and its derivatives, dienes, vinyl esters, vinyl ethers, vinyl pyridine derivatives, vinylsulphonic acid and its derivatives, vinylphosphonic acid and its derivatives and N-vinyl monomers, and
(E′) at least one polymer chosen from the polymers prepared by means of the process according to claim 1 and from the precursor block copolymers prepared by reacting at least one ethylenically unsaturated monomer as established in (A′) and at least one polymer chosen from the polymers prepared by the process according to claim 1 ,
said process comprising the steps whereby
(1′) at least one fraction of(A′) and at least one fraction of(E′) are introduced into a reactor, then
(2′) the contents of the reactor are reacted while introducing into the reactor the remainder, where appropriate, of (A′) and the remainder, where appropriate, of (E′), and
(3′) the reaction is ended.