Cationic laminar compounds and their production and use as stabi

Details Cationic laminar compounds and their production and use as stabi Cationic laminar compounds and their production and use as stabi

1999-02-04

2000-12-26

Dawson, Robert

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...

524436, 524437, 524176, 524174, 524567, C08K 300

Patent

active

061661244

DESCRIPTION:

BRIEF SUMMARY
BACKGROUND OF THE INVENTION

1. Field of the Invention
This invention relates to special cationic layer compounds of the hydrotalcite type, to a process for their production and to their use as stabilizers for halogen-containing plastics.
It is known that halogen-containing plastics or molding compounds produced from them tend to degrade or decompose on exposure to heat or high-energy radiation, for example ultraviolet light. To counteract this, they are normally treated with heavy metal compounds based, for example, on lead, barium and/or cadmium. For reasons of factory hygiene, however, there is a need to replace these thoroughly effective stabilizers by less health-damaging materials. Possible alternative stabilizers to the heavy metal compounds are, for example calcium and zinc soaps, but unfortunately they do not perform as well as the heavy metal compounds mentioned above so that co-stabilizers have to be used in order to enhance their stabilizing effect.
2. Discussion of Related Art
German patent DE-C-30 19 632 (Kyowa Chemical Ind.) describes the use of hydrotalcites for inhibiting the thermal or ultraviolet degradation of halogen-containing thermoplastic resins. This patent specification discloses test results which show that, when readily commercially available hydrotal-cites are incorporated, for example, in vinyl chloride resins, they accelerate the dechlorination of the resins on heating or even cause decomposition, blackening or foaming of the resins. In addition, it was found that these hydrotalcites show poor dispersibility in the resins and adversely affect the rheological properties of the resins during molding and also the appearance of the molded products obtained. These test results are attributed to the small crystal size of the usual hydrotalcites and to the large specific BET surface of at least about 50 m.sup.2 /g and the coverage of the hydrotalcite particles with water. Accordingly, it is proposed in German patent DE-C-30 19 632 to use hydrotalcites which have a large crystal size and a specific BET surface of no larger than 30 m.sup.2 /g and which may optionally be coated with an anionic surfactant, such as sodium stearate.
European patent application EP-A-189 899 (Kyowa Chemical Ind.) also describes resin compositions containing hydrotalcites having specific BET surfaces below 30 m.sup.2 /g. It is known from this European patent application that the hydrotalcites can be modified with higher fatty acid esters, anionic surfactants and coupling agents of the silane or titanium type in order to improve the compatibility of the hydrotalcite with the resins. According to cited European patent application EP-A-1 89 899, the hydrotalcites are said to be modified by mechanical mixing with the modifying agents in pure or dissolved form.
DEC-33 06 822 (Giulini Chemie) teaches that hydrotalcites with the formula [Mg.sub.6 Al.sub.2 (OH).sub.12 ](CO.sub.3).sub.2.xH.sub.2 O (with x.gtoreq.2) are obtained by reaction of aluminium hydroxide with magnesium hydroxide or magnesium oxide in the presence of basic magnesium carbonate as carbonate ion donor at a temperature of 50 to 100.degree. C. and subsequent spray drying from the suspension. The aluminium hydroxide is used in particular in the form of "active" aluminium hydroxide.
U.S. Pat. No. 4,656,156 (Aluminium Company of America) describes a process for producing hydrotalcite in which the aluminate liquor of the Bayer process is used as the aluminium component. The Bayer liquor is reacted with "active" magnesium oxide which can be obtained, for example, by calcining magnesium carbonate. This process can only be economically used in places where the Bayer liquor itself accumulates because otherwise relatively large quantities of water would again have to be transported.
DE-A-15 92 126 (Kyowa Chemical Ind.) describes the production of hydrotalcites from different starting materials, for example from a suspension of solid aluminium hydroxide, solid magnesium hydroxide and sodium hydrogen carbonate. The reactions are carried out in batches and the

REFERENCES:
patent: 3650704 (1972-03-01), Kumura et al.
patent: 4299759 (1981-11-01), Miyata et al.
patent: 4447417 (1984-05-01), Spickett et al.
patent: 4539195 (1985-09-01), Schanz et al.
patent: 4560545 (1985-12-01), Spickett et al.
patent: 4656156 (1987-04-01), Misra
patent: 5073584 (1991-12-01), Meszaros et al.
patent: 5106898 (1992-04-01), Nosu et al.
patent: 5416135 (1995-05-01), Endres et al.
patent: 5416141 (1995-05-01), Endres et al.
patent: 5539135 (1996-07-01), Breuer et al.
W.T. Reichle, "Anionic clay minerals", Chemtec (Jan. 1986) pp. 58-63.
Roempps Chemix-Lexikon (1973) p. 1539.
Kirk-Othmer, "Encyclopedia of Chemical Technology", vol. 7, 3rd ED. (1979) pp. 840-841.
Ullmann's ,"Encyclopedia of Industrial Chemistry", vol. A8, 5th Ed. (1987) pp. 586-601).
Ullman's ,Encyclopaedie der technischen Chemie, vol. 19, 4th Ed. (1980) pp. 2-11.
Ullmann's ,Encyclopaedie der technischen Chemie, vol. 16, 4th ED. (1978) pp. 254-257.
DIN 5033.

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