Synthetic resins or natural rubbers -- part of the class 520 ser – Synthetic resins – Cellular products or processes of preparing a cellular...
Patent
1996-12-11
1999-05-11
Foelak, Morton
Synthetic resins or natural rubbers -- part of the class 520 ser
Synthetic resins
Cellular products or processes of preparing a cellular...
521 56, 521 63, 521 64, 521149, 521150, C08J9/28
Patent
active
059028343
DESCRIPTION:
BRIEF SUMMARY
DESCRIPTION OF THE TECHNICAL FIELD AND THE RELEVANT PRIOR ART
The invention is concerned with novel macroporous particles which have an open pore structure, and also with a method of manufacturing such particles. The particles can be used as a supportive matrix in chromatography and in the solid-phase synthesis of oligopeptides and oligonucleotides, and also as microcarriers in the cultivation of cells, e.g. anchorage-dependent cells, and as a solid phase in heterogenic immunoassays, particularly when the particles are in a hydrophilic form.
In the context of the present invention, by spheres is meant spherical cavities and spherical particles, and also spheroidal forms thereof which are gently rounded and slightly elongated.
There has been a pronounced need of macroporous particles and their production for these applications for a number of years. Increased macroporosity will result in an improved flow through the particles, which, in turn, results in improved kinetics.
The inventive particles can be produced by polymerization in w/o/w emulsions. This type of emulsion can be considered as an aqueous emulsion of oil droplets which, in turn, contain a dispersed aqueous phase. W/o/w emulsions have earlier been used for the production of porous particles (Tioxide Group Service Ltd., GB-A-2,245,575). Particles have also been produced by cross-linking unsaturated polyesters with unsaturated monmers, such as styrene and divinylbenzene.
The inventive method employs the use of so-called inverse emulsions (water in oil emulsions, w/o emulsions) with a high internal phase content (=high internal phase emulsions). Polymerization in the oil phase of inverse emulsions has earlier been described by Sherrington (EP-A-60138) and Bayer AG (DE-A-1160616), among others. Relevant inverse emulsions will normally contain >60%, preferably >75%, water (w/w) and emulsifiers which are distributed to the oil phase (the monomer phase). Emulsifiers which provide such inverse emulsions will normally have an HLB value >2, preferably between 2-6. The HLB values can only be used as guidelines for determining whether or not an emulsifier is suited to a given type of inverse emulsion. The aforesaid ranges do not therefore exclude the possibility that emulsifiers with HLB values >6 will also provide inverse emulsions having a high content of internal phase.
DISCLOSURE OF THE INVENTION
In accordance with the inventive method, open, porous spherical particles are produced by polymerizing monovinyl monomers and polyvinyl monomers (cross-linkers) in an emulsion with the aid of the appropriate initiator. The method is characterized by emulsified therein droplets which contain a water-in-oil emulsion, wherein the oil phase in the droplets includes vinyl monomers and emulsifiers which provide an inverse emulsion and the droplets have a diameter smaller than 2,000 .mu.m, and wherein the total amount of water is between 75-99% (w/w), preferably 90-99%; and optionally after sieving, from the reaction mixture after the polymerization process.
Polymerization takes place in the intermediate phase, i.e. in the oil phase of the droplets.
In the case of the preferred embodiments, the w/o/w emulsion is formed in two stages. In Stage 1, there is prepared a water-in-oil emulsion (w/o emulsion) in which the oil phase constitutes about 5-45%, preferably 10-30% (w/w). Vinyl monomers and emulsifier are mixed with water in Stage 1, so as to form a water-in-oil emulsion, preferably while stirring. In Stage 2, the remainder of the water is added so as to form a w/o/w emulsion. Stirring of the mixture is normally interrupted while adding the remainder of the water and then recommenced. The initiator is preferably added in Stage 1 and may be either water-soluble or oil-soluble.
The oil phase (the intermediate phase) in the droplets normally contains emulsifier, vinyl monomer (e.g. mono- and difunctional monomers) and, when applicable, an oil-soluble initiator. The amounts of these components mostly add up to essentially 100% of the oil phase. The interm
REFERENCES:
patent: 3206441 (1965-09-01), von Bonin et al.
patent: 3244772 (1966-04-01), von Bonin et al.
patent: 3255127 (1966-06-01), von Bonin et al.
patent: 4522953 (1985-06-01), Barby et al.
patent: 5021462 (1991-06-01), Elmes et al.
patent: 5189070 (1993-02-01), Brownscombe et al.
patent: 5200433 (1993-04-01), Beshouri
patent: 5252621 (1993-10-01), Hodge
patent: 5583162 (1996-12-01), Li et al.
patent: 5653922 (1997-08-01), Li et al.
Foelak Morton
Pharmacia Biotech AB
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