Abstract The invention provides a process for the preparation of polymer latex. The process involves emulsification of an initiator or initiator mixture and optionally a solvent in the presence of an emulsifier in water in a first step and adding a monomer and polymerizing in a second step. The process is carried out by emulsifying an essentially water-insoluble initiator or initiator mixture in the first step at a temperature above the melting point of the initiator or initiator mixture if no solvent is used, and below its decomposition temperature, optionally together with an essentially water-insoluble liquid solvent, which forms a liquid solution together with the initiator or the initiator mixture at the emulsification temperature, then, in a second step adding the desired monomer, optionally additional emulsifier and water to a desired amount and initiating polymerization.
A process for the preparation of a polymer latex which comprises (a) forming a pre-emulsion either by emulsifying an initiator or initiator mixture having a water-solubility of <10 -2 g/l with water in the presence of an emulsifier at a temperature above the melting point and below the decomposition temperature of the initiator or initiator mixture, or, if a liquid solvent is additionally employed having a water-solubility of<10 -2 g/1 and a molecular weight <5000 in an amount effective to form a liquid solution with the initiator or initiator mixture emulsifying said solution with water in the presence of an emulsifier at a temperature below the decomposition temperature of the initiator or initiator mixture; (b) adding to said pre-emulsion a monomer corresponding to the desired polymer, optionally additional emulsifier and water to a desired amount whereby a major portion of the monomer is absorbed by drops in the pre-emulsion containing the initiator or initiator mixture; (c) and initiating polymerisation.
Claim 2
Dependent Claim
159 words
A process for the preparation of a polymer latex which comprises (a) forming a pre-emulsion either by emulsifying an initiator or initiator mixture having a water-solubility of <10 -2 g/l with water in the presence of an emulsifier at a temperature above the melting point and below the decomposition temperature of the initiator or initiator mixture, or, if a liquid solvent is additionally employed having a water-solubility of<10 -2 g/1 and a molecular weight <5000 in an amount effective to form a liquid solution with the initiator or initiator mixture emulsifying said solution with water in the presence of an emulsifier at a temperature below the decomposition temperature of the initiator or initiator mixture; (b) adding to said pre-emulsion a monomer corresponding to the desired polymer, optionally additional emulsifier and water to a desired amount whereby a major portion of the monomer is absorbed by drops in the pre-emulsion containing the initiator or initiator mixture; (c) and initiating polymerisation.
Claim 3
Dependent Claim
21 words
A process as claimed in claim 1 wherein the initiator or initiator mixture has a water solubility of <10 -4 g/litre.
Claim 4
Dependent Claim
22 words
A process as claimed in claim 1 or claim 2 wherein the liquid solvent has a water solubility of <10 -4 g/litre.
Claim 5
Dependent Claim
43 words
A process as claimed in claim 1 or claim 2 wherein in the absence of said liquid solvent, the initiator is oil-soluble and an amount of initiator from 0.5:1000 to 2:100 based on the total amount of water in the latex is used.
Claim 6
Dependent Claim
48 words
A process as claimed in any of claims 1 to 3 wherein said liquid solvent is employed in an amount in proportion to water in the latex of 0.5:1000 to 5:100 and is present in an amount in proportion to initiator of from 0.05:1 to 10:1 by weight.
Claim 7
Dependent Claim
38 words
A process as claimed in any of claims 1 to 5 wherein an anionic,cationic or non-ionic emulsifier is employed in a total amount of from 1:1000 to 5:100 based on the total amount of water in the latex.
Claim 8
Dependent Claim
32 words
A process as claimed in any of claims 1 to 6 wherein the amount of monomer employed is from 0.5:1 to 2:1 based on the total amount of water in the latex.
Claim 9
Dependent Claim
19 words
A process as claimed in any of claims 1 to 7 wherein the monomer is vinyl chloride or styrene.
Claim 10
Dependent Claim
31 words
A process as claimed in any of claims 1 to 8 wherein said pre-emulsion is mixed with a seed of polymer particles or other emulsion prior to addition of the monomer.