DE1643205A1 - Stabilization of monomeric, ethylenically unsaturated compounds - Google Patents

Description

WACKER-GHEMIE Munich, 2-9. October 1969

GMBH

ix / patient abb. Dr.S / Kr

P 16 43 205.6 Int. Mr. Va 664-3

Stabilization of monomeric, ethylenically unsaturated compounds

As is known, monomers have to be used during storage, transport, if necessary be stabilized against undesired polymerization during production. In general, the desired inhibition of polymerization is achieved through the addition of certain Stabil! « izing agent reached. Such a stabilizer is said to be be as soluble as possible in the monomer in order to ensure uniform distribution to ensure. On the other hand, it should allow polymerization, for example, at elevated temperatures, the presence of oxygen and for a longer period of time Prevent storage and can easily be separated from the monomers again · With the commonly used for cleaning Distillation of the monomer must complete the stabilizer lag behind.

Known stabilization agents are, for example, amino compounds (TJ3-? Atent 2 9Γ.6 200, 2 609 387), phenazine dyes (DBP 104-775) or phenols (THAT 1 215 134). However, the effectiveness of the latter is compromised by Eiaon.

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It has now been found that a good stabilizer effect is achieved when a mixture of

Λ) Thioblephenol, which is the group of the general formula

OH OH '

B) and / or diphenylamine, which is the group of the general formula

C) and / or a phenazine dye & ₉ in the form of the free base or its salt, which is the group of the general formula

contains «that with tetralin, possibly with the addition of chlorinated hydrocarbon oils sum stabilization of monomeric ethylenically unsaturated compounds possibly recovered from polymerisation batches is used · saber has proven to be swecloaassig » if a mixture that is about 0.1 to 90 # »preferably 1 to 10 #, A and / or B and / or C contains, in an amount of 0.001-0.01 #, based on the monomer, is used

The thiobisphenols used are preferably those which are alkyl-substituted are, for example, di-t-butyl-p-cresol monosulfide, di-thymol monosulfide, Di-m-kreßolnonosulfid, Di-Cp-t-butyl-catechol) -inono-sulfide, Di-carvncrolmonosulfld.

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BATH ORIGINAL

Boi amines using diphenyl it has likewise proven advantageous if Alkylsubotituierte be employed z · B · _f 4 4 ^l -Dioctyldiphenylainin, Monco styldiphenylamin or mixtures of different Ootyldiphenylamine ·

Possible phenazine dyes are indulin, for example (known under the trade name Indulin N), Rosinduline, Isorosinduline. Safranine, Higrosine and Benzolinduline

If the stabilizers mentioned above are used in a mixture with tetralin, they have a strongly synergistic effect in the stabilization of monomers. They are used for ethylenically unsaturated compounds such as styrene, derivatives des styrenes, divinylbenzene, in the case of ethylenically unsaturated carboxylic and dicarboxylic acids, and their anhydrides and esters, e.g. Acrylic acid, methacrylic acid, fumaric acid, maleic acid, itaconic acid, for vinyl compounds such as 2 · B. vinyl halides, vinylidene halides ^ nide, vinyl ester, vinyl ether, II-vinyl nitrogen compounds. Preferred However, if they are used with vinyl chloride and mixtures of vinyl chloride with other monomers, possibly vinyl acetate

The mode of action of the stabilizing agent mixture according to the invention results from the following experiments:

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125 parts vinyls & Loi & i were »it 0.3 feile" BiXauroylperoxid by the suspension process over 20 hours at 54 ° 0 poly "aerisiert · If the Auebeute of polyvinyl chloride without the addition of inhibitory coats assumed 1OQ%, so calibration result from the addition of the following Stabilieierungomittelgemieoht following Exploit

attempt contained stabilizer II III IV 0.3 $ Yield of l "öly" Mr* (in % based on monomer es) . _- 0.3 vinyl chloride I. 0.01 • 0.3 i) 0.01 0.01 0.01 0.3 2) - • 86 3) - 87 *) 0.01 77 0, CM mm 12th 6) 2 * 7) -

Mean

2.2 · -Thiobis * - (^ -methyl-e-t-butyl-phenol), (2.2 · «dihydroxy- ^, 3 'ditertiBrbutyl-5,5 * -dimethyl-phenyl-iaonosulfid) according to the

formula

HO

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~. 5 -

4,4 - »- dioctyldiphenylamine

III Indulin (known under the trade name Indulin H)

IV tetralin

It can be seen from the experiments that when polymerizing Vinyl chloride with the addition of tetralin and in each case small amounts of the compounds I, II and III have a strongly synergistic effect

inhibition of polymerization occurs.

The stabilizer systems according to the invention are particularly advantageous in the stabilization of monomers recovered from polymerization batches, for example vinyl chloride or vinyl chloride / vinyl acetate mixtures.These residual monomers are distilled back in order to be reused.Generally, monomers recovered from polymerization batches are mostly more or less moist monomers The back-distillation plants are ready to polymerize and the devices ( made of VgA steel are less polymerized than those made of ordinary iron.The effect of stabilizers, which are sufficient for dry and fresh monomers, is no longer sufficient in this case.

By using the above stabilizers in a mixture Tetrelin will polymerize lines and others Parts of the distillation plant for moist residual monoiaeres, even at higher temperatures, as well as in the presence of rietallen, such as

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Iron, avoided. Correspondingly expensive distillation systems, made of V ^ A steel, can when using the erfindungsgenäßec Stabilizing agent practicable without cleaning of ears and columns run for an unlimited time »Significantly cheaper systems ordinary iron, which with the previously known stabilizers]! after very short periods of time and had to be cleaned in a complex manner, can now when using the invention Stabilizing agents in economically justifiable Can be operated for long periods of time without cleaning

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Claims (2)

Claims · Use a «mixture of» ._. ".". (Ehioblephenol, dae the group of the aXlgeaei »©» formula OH OH and / or B) Diphenylamine, which is the group of the general formula and / or C) a phenazine compound in the form of the free base or its salt containing the group of the general formula with tetralin, optionally with the addition of chlorinated hydrocarbons, to stabilize monomeric, optionally recovered from polymerization batches ethylenically unsaturated compounds 2. Use of a mixture according to claim 1, gekennaeichnet by a content of about 0.1 to 90 #, preferably up to 10 #, A and / or B and / or C ₁ in a quantity of 0.001-0.01% _t based on the monomer, is used 209820/1168