Synthetic resins or natural rubbers -- part of the class 520 ser – Synthetic resins – Processes of preparing a desired or intentional composition...
Reexamination Certificate
1997-08-22
2001-01-16
Buttner, David J. (Department: 1712)
Synthetic resins or natural rubbers -- part of the class 520 ser
Synthetic resins
Processes of preparing a desired or intentional composition...
C524S245000, C524S317000, C524S375000, C524S376000, C524S377000, C528S501000
Reexamination Certificate
active
06174946
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to agglomerated particles of water-swellable addition polymers, the agglomerated particles having an average particle diameter of from 20 to 5000 &mgr;m and consisting of primary particles having an average particle diameter of from 0.1 to 15 &mgr;m, being preparable by polymerization of water-soluble monomers in the presence of regulators and of crosslinking agents in the manner of a water-in-oil polymerization and subsequent azeotropic removal of water from the water-in-oil polymer emulsions, containing the primary particles, in the presence of agglomerating polyalkylene glycols which
(a) are obtainable by an addition reaction of C
2
-C
4
-alkylene oxides with alcohols, phenols, amines or carboxylic acids, and
(b) contain at least 2 polymerized alkylene oxide units,
and disintegrating into the primary particles on introduction into an aqueous medium, to processes for preparing the agglomerated polymer particles, and to their use as thickeners for increasing the viscosity of aqueous systems.
2. Description of the Background
DE-C-36 41 700 discloses a process for preparing water-in-oil emulsions of crosslinked, water-swellable addition polymers by polymerizing water-soluble monomers and crosslinkers in the form of a water-in-oil emulsion using water-soluble azo initiators in the presence of emulsifiers having an HLB value of at least 10. The polymers are not isolated, but are used directly in the form of the water-in-oil polymer emulsions as thickeners, for example for preparing textile print pastes.
EP-A-0 343 840 discloses finely divided crosslinked addition polymers having a particle size of <20 &mgr;m. They are prepared by polymerizing water-soluble monomers together with crosslinkers in the manner of a water-in-oil polymerization in the presence of free-radical polymerization initiators. The polymers are again not isolated; instead, the water is merely substantially distilled out of the emulsions and the emulsions are subsequently admixed with an oil-in-water emulsifier to facilitate dispersion of the mixture in water. The polymers are used as thickeners in pigment print pastes. In pigment printing, the thickener remains on the printed textile material together with the binder of the pigment print paste. However, the above-described thickeners are not suitable for textile printing with print pastes which contain soluble dyes, such as reactive dyes or disperse dyes, since such textile prints are subsequently washed and the thickener is not completely removable. The known thickeners remain on the textile material and give it a harsh hand. The known thickeners are also electrolyte-sensitive, so that they are not sufficiently effective on printing with reactive dyes, where the print pastes contain relatively large amounts of salts as well as the ionic dye.
WO-A-92/13912 discloses the agglomerated polymer particles described at the beginning. The agglomerated polymer particles are present in the form of a powder. The crosslinked, water-swellable polymer powders are used as thickeners for aqueous systems, in particular as thickeners for textile print pastes. However, these polymers have the disadvantage that they cannot be washed off and so impart too harsh a hand to the printed material.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide novel substances which, on use as thickeners for printing with soluble dyes, are readily washed out of the printed material and which exhibit a good thickening effect in electrolyte-containing print pastes.
We have found that this object is achieved according to the present invention by agglomerated particles of water-swellable addition polymers, the agglomerated particles having an average particle diameter of from 20 to 5000 &mgr;m and consisting of primary particles having an average particle diameter of from 0.1 to 15 &mgr;m, being preparable by polymerization of water-soluble monomers in the presence of regulators and of crosslinking agents in the manner of a water-in-oil polymerization and subsequent azeotropic removal of water from the water-in-oil polymer emulsions, containing the primary particles, in the presence of agglomerating polyalkylene glycols which
(a) are obtainable by an addition reaction of C
2
-C
4
-alkylene oxides with alcohols, phenols, amines or carboxylic acids, and
(b) contain at least 2 polymerized alkylene oxide units,
and disintegrating into the primary particles on introduction into an aqueous medium, when the water-in-oil polymerization is carried out using the regulators in amounts from 1 to 10% by weight and the crosslinkers in amounts of at least 2000 ppm, each based on the monomers.
The present invention also provides a process for preparing the abovementioned agglomerated polymer particles by polymerizing water-soluble monomers in the aqueous phase of a water-in-oil emulsion in the presence of water-in-oil emulsifiers, polymerization initiators, regulators and crosslinkers and subsequent azeotropic removal of water from the water-in-oil polymer emulsions in the presence of from 1 to 40% by weight, based on the monomers, of agglomerating polyalkylene glycols which
(a) are obtainable by an addition reaction of C
2
-C
4
-alkylene oxides with alcohols, phenols, amines or carboxylic acids, and
(b) contain at least 2 polymerized alkylene oxide units,
by agglomeration of the primary particles of the water-in-oil polymer emulsions and isolating the agglomerated polymer particles, by using the regulators in amounts from 1 to 10% by weight and the crosslinkers in amounts of at least 2000 ppm, each based on the monomers.
DETAILED DESCRIPTION OF THE INVENTION
The polymerization can be carried out with all water-soluble ethylenically unsaturated monomers. These monomers are for example ethylenically unsaturated C
3
-C
6
-carboxylic acids, such as acrylic acid, methacrylic acid, itaconic acid, maleic acid, fumaric acid and methacrylic acid and also the amides thereof, especially acrylamide and methacrylamide. Further suitable water-soluble monomers are for example acrylamidomethylpropanesulfonic acid, vinylsulfonic acid, vinylphosphonic acid and vinyllactic acid.
Further suitable water-soluble ethylenically unsaturated monomers are di-C
1
-C
3
-alkylamino-C
2
-C
6
-alkyl (meth)acrylates, such as dimethylaminoethyl acrylate, dimethylaminoethyl methacrylate, diethylaminoethyl acrylate, diethylaminoethyl methacrylate, dimethylaminopropyl acrylate, dimethylaminobutyl acrylate, dimethylaminoneopentyl acrylate and dimethylaminoneopentyl methacrylate. The basic acrylates can be subjected to the polymerization in the form of the salts with inorganic acids or carboxylic acids having from 1 to 4 carbon atoms or else in quaternized form. Also suitable are olefinically unsaturated nitriles, such as acrylonitrile.
It is also possible to use water-soluble diallylammonium compounds of the general formulae
where X
−
is a halide ion, such as chloride, fluoride, bromide or iodide, or a hydroxide, nitrate, methosulfate, hydrogensulfate or dihydrogenphosphate ion, n and m are each integers from 1 to 2, preferably n=m=2,
Y is
preferably an oxygen atom or a
group, and
R
1
, R
2
, R
3
and R
4
are each a hydrogen atom or an alkyl radical having from 1 to 6 carbon atoms and R
5
and R
6
are each H or an alkyl radical, which can be straight-chain or branched, having from 1 to 18 carbon atoms, preferably from 1 to 6 carbon atoms, or an aryl and/or benzyl radical.
Such diolefinically unsaturated monomers include for example dimethyldiallylammonium chloride, dimethyldiallylammonium bromide, diethyldiallylammonium chloride, methyl-tert-butyldiallylammonium methosulfate, methyl-n-propyldiallylammonium chloride, dimethyldiallylammonium hydrogensulfate, dimethyldiallylammonium dihydrogenphosphate, di-n-butyldiallylammonium bromide, diallylpiperidinium bromide, diallylpyrrolidinium chloride and diallylmorpholinium bromide.
It is also possible to use N-vinylpyrrolidones, such as N-vinylpyrrolidone. It is
Hartmann Heinrich
Meyer Harald
Nieberle J{umlaut over (u)}rgen
R{umlaut over (u)}benacker Martin
Schneider Reinhard
BASF - Aktiengesellschaft
Buttner David J.
Oblon & Spivak, McClelland, Maier & Neustadt P.C.
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