Synthetic resins or natural rubbers -- part of the class 520 ser – Synthetic resins – At least one aryl ring which is part of a fused or bridged...
Patent
1997-04-03
1998-05-26
Reddick, Judy M.
Synthetic resins or natural rubbers -- part of the class 520 ser
Synthetic resins
At least one aryl ring which is part of a fused or bridged...
524458, 524723, 524819, 524820, 524821, 524822, 524823, 524824, 524828, 524829, 524831, 524832, 524827, 524833, 524804, 526220, C08F 216
Patent
active
057565740
DESCRIPTION:
BRIEF SUMMARY
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a process for the preparation of an aqueous polymer emulsion, in which an aqueous emulsion of a polymer which contains at least one chemically bonded monomer having at least one ethylenically unsaturated group is produced in a manner known per se so that the total content of free monomers having at least one ethylenically unsaturated double bond, ie. monomers of this type which are not chemically bonded (referred to in this publication as content of residual monomers or residual monomer content), in the aqueous polymer emulsion is from >0 to .ltoreq.1% by weight, based on the polymer content of the aqueous polymer emulsion, and this residual monomer content is then reduced by the action of a free radical redox initiator system comprising at least one oxidizing agent and at least one reducing agent.
2. Description of the Background Art
Aqueous polymer emulsions are fluid systems which contain polymer particles present in stable disperse form as the disperse phase in an aqueous dispersing medium. The diameter of the polymer particles is in general mainly from 0.01 to 5 .mu.m, frequently mainly from 0.01 to 1 .mu.m. The stability of the disperse phase often extends over a period of .gtoreq.1 month, frequently even over a period of .gtoreq.3 months. The proportion by volume of the polymer in the aqueous polymer emulsion is normally from 10 to 70% by volume, based on the total volume of the aqueous polymer emulsion.
As in the case of polymer solutions when the solvent is evaporated, aqueous polymer emulsions have the property of forming polymer films when the aqueous dispersing medium is evaporated, and said emulsions are therefore widely used as binders, for example for surface coatings or materials for coating leather.
In principle, a person skilled in the art categorizes aqueous polymer emulsions as aqueous secondary emulsions and aqueous primary emulsions. The aqueous secondary emulsions are those in the preparation of which the polymer is produced outside the aqueous dispersing medium, for example in solution in a suitable non-aqueous solvent. This solution is then transferred to the aqueous dispersing medium and the solvent is separated off, as a rule by distillation, with dispersing. In contrast, aqueous primary emulsions are those in which the polymer is produced in the aqueous dispersing medium itself and is present immediately as a disperse phase. The common feature of all preparation processes is essentially that monomers which have at least one ethylenically unsaturated group are concomitantly used for synthesizing the polymer, or that this synthesis is effected exclusively from such monomers.
Incorporation of such monomers having at least one ethylenically unsaturated group is usually carried out by an initiated polymerization reaction, the type of initiation being determined in particular by the desired performance characteristics of the end product and therefore being adapted to these. For example, ionic or free radical initiation is suitable. However, the incorporation may also be effected by catalytically initiated polymer-analogous reaction. Free radical initiation is particularly frequently used and hence the incorporation of the one or more monomers having at least one ethylenically unsaturated group is carried out as a rule by the free radical aqueous emulsion polymerization method in the case of aqueous primary emulsions and as a rule by the free radical solution polymerization method in the case of aqueous secondary emulsions.
Since, when the required periods are taken into account, it is generally not useful to attempt to achieve complete conversion with regard to the incorporation of the one or more monomers having at least one ethylenically unsaturated group while maintaining the actual polymerization reaction conditions determining the desired properties (for example molecular weight, molecular weight distribution, degree of branching, etc.) of the end product, the aqueous polymer emulsions resu
REFERENCES:
patent: 3165500 (1965-01-01), Logemann et al.
patent: 3179613 (1965-04-01), Guenther et al.
patent: 3344128 (1967-09-01), Uraneck
patent: 3870673 (1975-03-01), Rauterkus et al.
patent: 4147845 (1979-04-01), Peterson
patent: 4244690 (1981-01-01), Sato et al.
patent: 4426501 (1984-01-01), Khan
patent: 4529753 (1985-07-01), Taylor
patent: 4678848 (1987-07-01), Walter
patent: 4786698 (1988-11-01), Musch et al.
patent: 4839447 (1989-06-01), Casper et al.
patent: 4975501 (1990-12-01), Musch et al.
patent: 5021469 (1991-06-01), Landerbeins et al.
patent: 5087676 (1992-02-01), Heider et al.
patent: 5376703 (1994-12-01), Noelken et al.
patent: 5408019 (1995-04-01), Mertens et al.
patent: 5414193 (1995-05-01), Taylor et al.
patent: 5453485 (1995-09-01), Huth et al.
AMA 142-143 Ambenoniumchlorid.
24, Datum des Patentblattes: 9.4.53, Bestell-Nr. o4345/53, pp. 1-4.
Baumstark Roland
Rupaner Robert
BASF - Aktiengesellschaft
Reddick Judy M.
LandOfFree
Process for preparing an aqueous polymer dispersion does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Process for preparing an aqueous polymer dispersion, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Process for preparing an aqueous polymer dispersion will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1961015