Water Based Concentrated Product Forms of Photoinitiators Made by a Heterophase Polymerization Technique
The invention relates to a concentrated aqueous polymer dispersion with an average particle size of less than 1000 nm comprising g) a polymer carrier prepared by heterophase radical polymerization of at least one ethylenically unsaturated monomer in the presence of h) a non-polar photoinitiator and/or photolatent catalyst and i) optionally a non-ionic, cationic or anionic surfactant, wherein the weight ratio of the non-polar photoinitiator and/or photolatent catalyst to the polymer carrier is greater than 20 parts of photoinitiator and/or photolatent catalyst per 100 parts of polymer carrier.
1 - 6 . (canceled)
7 . A process for the preparation of a concentrated aqueous polymer dispersion with an average particle size of less than 1000 nm comprising the step
polymerizing at least one ethylenically unsaturated monomer in the presence of a photoinitiator and/or a photolatent catalyst by heterophase radical polymerization; wherein the weight ratio of the photoinitiator and/or a photolatent catalyst to the polymer carrier formed from the ethylenically unsaturated monomer is equal or greater than 35 parts of photoinitiator and/or photolatent catalyst per 100 parts of polymer carrier.
8 . A process according to claim 7 comprising the steps of
a) dissolving, emulsifying or dispersing a photoinitiator and/or photolatent catalyst in at least one ethylenically unsaturated monomer;
b) preparing a conventional oil in water emulsion of said photoinitiator and/or photolatent catalyst dissolved, emulsified or dispersed in at least one ethylenically unsaturated monomer;
c) homogenizing the conventional emulsion to a mini-emulsion wherein the droplets of the organic phase have an average diameter below 1000 nm;
d) polymerizing the mini-emulsion by adding a polymerization initiator; wherein the weight ratio of the photoinitiator and/or a photolatent catalyst to the polymer carrier formed from the ethylenically unsaturated monomer equal or greater than 35 parts of photoinitiator and/or photolatent catalyst per 100 parts of polymer carrier.
9 . A process for preparing a polymer powder by preparing a concentrated aqueous polymer dispersion according to claim 7 followed by vaporizing the volatile components of the concentrated aqueous polymer dispersion.
10 . A polymer powder obtainable by a process according to claim 9 .
11 . Aqueous or non-aqueous formulations, coatings, inks, adhesives or in formulations for electronic materials comprising the aqueous polymer dispersion prepared according to claim 7 .
12 . A process for preparing a polymer powder by preparing a concentrated aqueous polymer dispersion according to claim 8 followed by vaporizing the volatile components of the concentrated aqueous polymer dispersion.
13 . A polymer powder obtained by a process according to claim 12 .
14 . Aqueous or non-aqueous formulations, coatings, inks, adhesives or in formulations for electronic materials comprising the polymer powder according to claim 10 .
15 . Aqueous or non-aqueous formulations, coatings, inks, adhesives or in formulations for electronic materials comprising the polymer powder according to claim 13 .