Synthetic resins or natural rubbers -- part of the class 520 ser – Synthetic resins – Processes of preparing a desired or intentional composition...
Patent
1998-09-08
2000-11-14
Cain, Edward J.
Synthetic resins or natural rubbers -- part of the class 520 ser
Synthetic resins
Processes of preparing a desired or intentional composition...
524 89, C08K 534
Patent
active
061471453
DESCRIPTION:
BRIEF SUMMARY
The present invention relates to monomer compositions containing selected from the group consisting of the halogens, nitrogen, oxygen, sulfur or silicon, and hydrogen on the .alpha.-carbons, in an amount effective as stabilizer against premature polymerization.
The invention further relates to processes for inhibiting the premature polymerization of vinyl-containing monomers and to the use of N-oxyl compounds of secondary amines which do not bear hydrogen on the .alpha.-carbons as stabilizers against premature polymerization.
To prevent premature polymerization, it is necessary to add stabilizers to the monomers. Those which have proved particularly suitable for preventing free-radical polymerizations are sterically hindered amines, such as 2,2,6,6-tetraalkylpiperidine, and their derivatives, including also the N-oxyl derivatives.
U.S. Pat. No. 5,254,760 describes the stabilization of vinylaromatic compounds such as styrene during distillation and purification by a combination of at least one nitroxyl compound and at least one aromatic nitro compound, in which there is the risk that traces of the nitroxyl compounds pass into the purified monomer. Even traces of nitroxyl compounds interfere with the subsequent polymerization, however; they cause delayed polymerization and uncontrolled chain breaks, leading to polymers which are insufficiently reproducible and are of short chain length. These disadvantageous effects are described by Mardare et al. in Polym. Prep. (Am. Chem. Soc., Div. Polym. Sci.) 35 (1), 778 (1994).
To stabilize heterosubstituted vinyl compounds such as N-vinylformamide or N-vinylpyrrolidone, derivatives of phenylenediamine (U.S. Pat. No. 5,396,005), fullerenes (DE-A 44 14 773) or 2,6-di-tert-butyl-p-cresole (DE-A 43 28 950), for example, have previously been used in distillation and purification, but the efficiency of these stabilizers is considered to be inadequate.
It is an object of the present invention, therefore, to find monomer compositions which contain heterosubstituted vinyl compounds and suitable stabilizers, which display improved stabilization against premature polymerization and which have virtually no disadvantageous effects on the following targeted polymerization of the monomers.
We have found that this object is achieved by the monomer compositions mentioned at the outset.
The heterosubstituted vinyl monomers preferably bear, as hetero-atom on the vinyl group, halogens, oxygen, nitrogen or sulfur.
Hetero-substituted vinyl monomers which are suitable are, for example, vinyl halides, such as vinyl chloride, vinyl esters of carboxylic acids, such as vinyl acetate, vinyl propionate or vinyl butyrate, vinyl ethers, such as methyl vinyl ether, ethyl vinyl ether or butyl vinyl ether, vinyl thioethers, vinyl carbazoles, vinyl pyrrolidones, vinyl phthalimides, vinyl isocyanates, vinylcaprolactams, vinylimidazoles, vinylformamide, vinylsulfonic acid and vinylsilanes, such as vinyltriacetoxysilane, vinyltrichlorosilane or vinyltrimethoxysilane.
Preferred monomer compositions contain ##STR1## or --R.sup.3 , R.sup.2 is hydrogen, C.sub.1 -C.sub.4 -alkyl or, together with R.sup.3, is a saturated or unsaturated C.sub.3 -, C.sub.4 - or C.sub.5 -alkylene bridge in which up to two CH.sub.2 groups can be replaced by NH, N(C.sub.1 -C.sub.4 -alkyl), N(C.sub.6 -C.sub.10 -aryl) or oxygen and up to two CH groups can be replaced by N and with R.sup.2, is a saturated or unsaturated C.sub.3 -, C.sub.4 - or C.sub.5 -alkylene bridge in which up to two CH.sub.2 groups can be replaced by NH, N(C.sub.1 -C.sub.4 -alkyl), N(C.sub.6 -C.sub.10 -aryl) or oxygen and up to two CH groups can be replaced by N, and hydrogen on the .alpha.-carbons in an amount effective as stabilizer against premature polymerization.
The monomers (A) of the general formula I which are present in the mixtures of the invention can contain oxygen as the variable X. Monomers of this type which are particularly suitable as a constituent of the novel monomer compositions are vinyl ethers in which R.sup.1 is C.sub.1 -C.sub.4 -alkyl, i.e.
REFERENCES:
patent: 4670131 (1987-06-01), Ferrell
patent: 4972009 (1990-11-01), Suhadolnik et al.
patent: 4983738 (1991-01-01), Kazmierczak et al.
patent: 5254760 (1993-10-01), Winter et al.
patent: 5396005 (1995-03-01), Arhancet
Thermal Polymerization of Styrene in the Presence of Stable Radicals and Inhibitors Mardare et al. In Polym. Prep. (Am. Chem. Soc., Div. Polym. Sci.) 35 (1), 778 (1994).
Aumuller Alexander
Dupuis Jacques
Koch Andreas
Niessner Manfred
Sutoris Heinz Friedrich
BASF - Aktiengesellschaft
Cain Edward J.
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