Compositions: coating or plastic – Coating or plastic compositions
Patent
1996-03-08
1998-05-05
Rose, Shep K.
Compositions: coating or plastic
Coating or plastic compositions
106270, 106271, 424 49, C09G 108, C09F 102, C08L 1106, A61K 716
Patent
active
057468125
DESCRIPTION:
BRIEF SUMMARY
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to novel aqueous polyolefin wax dispersions which contain
A) from 5 to 65% by weight of polyethylene wax or polypropylene wax having a mean particle size of from 1 to 50 .mu.m and an acid number of less than 5 mg of KOH/g of wax and
B) from 0.5 to 20% by weight of a glyceride of predominantly ethylenically monounsaturated or polyunsaturated C.sub.16 -C.sub.22 -monocarboxylic acids which may additionally contain hydroxyl groups, which glyceride has been reacted with from 1 to 50 mol of a 1,2-alkylene oxide of 2 to 4 carbon atoms, as a dispersant.
2. Description of the Related Art
Aqueous wax dispersions based on polyethylene or polypropylene can be prepared in principle by two methods: as primary dispersions by polymerization of ethylene or propylene in a surfactant-containing aqueous phase under superatmospheric pressure and in the presence of an initiator system or as secondary dispersions by dispersing dispersible polyethylene or polypropylene waxes in powder form with the aid of a suitable dispersant system. Emulsifiable waxes are usually understood here as meaning low molecular weight polyolefin chains functionalized with carboxylate, keto or hydroxyl groups; said chains can be prepared either by copolymerization of ethylene or propylene with, for example, unsaturated carboxylic acids, such as acrylic acid, or by atmospheric oxidation of polyolefin waxes.
Primary dispersions generally have particle sizes of from 0.01 to 0.25 .mu.m, whereas it has been possible to date to prepare stable secondary dispersions having a mean particle size of only up to almost 1 .mu.m. Dispersions having larger particles tend to undergo phase separation owing to the low density and the hydrophobic nature of the polyolefin wax.
In both preparation methods, only solids contents of up to about 35% by weight can usually be achieved. Higher wax contents are achievable in relatively high amounts only with difficulties and in the presence of suitable assistants.
U.S. Pat. No. 4,371,658 discloses spinning assistants for the production of polyamide yarns, which comprise a mixture of various emulsifiers, oxidized polyethylene having an acid number of from about 14 to 32 and alkali metal hydroxide in aqueous emulsion. Castor oil reacted with from 2 to 16 mol of ethylene oxide is mentioned as an emulsifier component.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide stable aqueous polyolefin wax dispersions which, owing to the performance characteristics required, have a mean particle size of substantially more than 1 .mu.m and a virtually unlimited shelf life. Furthermore, it should be possible to prepare these dispersions in a very simple manner and with very few assistants. The dispersions should be based on unfunctionalized polyolefin wax, ie. without stabilizing carboxylate groups.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
We have found that this object is achieved by the aqueous polyolefin wax dispersions defined at the outset. As a result of the choice of the dispersant system B, it is now possible to obtain stable polyolefin wax dispersions having the desired properties by simply stirring the appropriate fine (micronized) wax powder together with the dispersant at room temperature into water. Solids contents of up to 65% by weight can be realized.
The mean particle size of the polyolefin waxes A in the novel dispersions is from 1 to 50 .mu.m, in particular from 3 to 20 .mu.m, especially from 5 to 15 .mu.m. The mean particle size can best be determined by the Coulter method.
Commercial unfunctionalized polyethylene waxes having weight average molecular weights from 500 to 10,000, in particular from 1000 to 5000, g/mol or polypropylene waxes having weight average molecular weights of from 5000 to 50,000, in particular from 15,000 to 30,000, g/mol or mixtures thereof are used. The content of polyethylene or polypropylene in these waxes is more than 99% by weight. These waxes are finely comminuted by conventional met
REFERENCES:
patent: 2928752 (1960-03-01), Felletschin
patent: 3563910 (1971-02-01), Fishmon
patent: 3906117 (1975-09-01), Gawrilon
patent: 3934003 (1976-01-01), Tuma et al.
patent: 3944492 (1976-03-01), Wheeler
patent: 4110234 (1978-08-01), Loveless et al.
patent: 4164563 (1979-08-01), Chang
patent: 4191673 (1980-03-01), Wiesman
patent: 4371658 (1983-02-01), Marshall et al.
patent: 5017222 (1991-05-01), Cifuentes et al.
patent: 5021185 (1991-06-01), Mustakallio
patent: 5094687 (1992-03-01), Elepano
patent: 5123964 (1992-06-01), Kerner et al.
patent: 5319015 (1994-06-01), Gebhardt et al.
patent: 5340486 (1994-08-01), Willoughby
patent: 5376170 (1994-12-01), Baker
patent: 5397384 (1995-03-01), Wisnienski
patent: 5523025 (1996-06-01), Erilli
patent: 5531995 (1996-07-01), Lubetzky et al.
CRC Handbook of Chemistry and Physics "Buffer Solutions" 63th edition, 1982-1983, pp. D154-D156.
CRC Handbook of Chemistry and Physics "Buffer Solutions" 65th edition, 1984-1985, pp. D148-150.
Database WPI, Section Ch, Week 9102, Derwent Publications Ltd., London, Great Britain, DD, A 281 310, 914, Aug. 8, 1990 micronized oxidized polyethylene wax acid no & dispersant.
Database WPI Section Ch, Week 8947, Derwent Publications Ltd., London, Great Britain, JP, A 1 258 914, Oct. 16, 1989 micronized polyethylene wax.
Klingelhofer Paul
Muller Michael Wolfgang
Weiss Stefan
BASF - Aktiengesellschaft
Rose Shep K.
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