CS201311B1 - Esters of 3,3'thiodipropionic acid - Google Patents

Description

The invention relates to stabilizers for polyolefins. These stabilizers are esters of 3,3'-thiodipropionic prepared by mixing the acid and the epoxides (I) wherein 2'n / 21n nam is 0-18, n + m is from 12 to 36, X is hydrogen or a carboxyalkyl ₀ C00C II _{r + 2r 1} , where r is up to 5, in a ratio such that each carboxyl group has from 0.7 to 5

0.95 grams of oxirane oxygen. The reaction is catalyzed by oxides or carbonates

Groups of the periodic system or metal salts I and groups with aliphatic raonocarboxylic acids. Stabilizers are liquid and low volatile.

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Alkylated phenols, whose antioxidant effect is further enhanced by the synergistic action of 3,3'-thiodipropionic esters, are used to stabilize the olefin poles against the degradative action of atmospheric oxygen at normal and especially at elevated temperature.

To synthesis Ucklo _és W _e é KéYóu iwitá iIImW aliphatic We, iqdí. floflocyl *, tetradecyl or octadecyl alcohol.

Said esters are waxy substances with a relatively low melting point (e.g., diester of 3,3'-thiodipropionic acid with dodeoyl alcohol has a melting point of 38.5 to 39.5 ° C), which causes difficulties in feeding into the polymer by waxy particles they stick, stick to the dosing device, form lumps, and the dosing accuracy deteriorates. A further disadvantage of using these esters is their volatility, especially when polymers exposed to long-term thermal stress in air are stabilized by this synergistic system. Indeed, it has been found that by gradually volatilizing some of the components of the synergistic system, its composition gets outside the synergistic optimum range and the stabilizing efficiency of the system naturally decreases.

It has now been found that it is possible to prepare liquid esters of thiodipropionic acid, 3,3 ^J with lower volatility, when applied to esterification, instead of the alcohol moieties are aliphatic compounds containing bound oxygen in the oxirane ring. Upon opening of this ring, the addition of 3,3 ' -thiodipropionic acid carboxylates gives the ester.

The present invention provides 3,3'-thiodipropionic acid esters prepared by mixing 3,3'-thiodipropionic acid with epoxides of the general formula I ^H (Cl ₂ ) _n -OH 4 -CH- (CH ₂ ) _m X 0 (I), wherein NAM 0-18, wherein the sum of n + m is 12 to 3δ, X is hydrogen or a carboxyalkyl C00C _r H _{2r + 1} wherein r is 3-5, in a ratio such that for each carboxylic acid group accounted for 0.7 0.95 grams of oxirane oxygen and heating, preferably in the presence of 0.1 to 5% by weight (based on the weight of epoxide I) of catalysts such as oxides or metal carbonates II. groups of the periodic system or metal salts 1a. groups of the periodic system with aliphatic monocarboxylic acids for 30 to 600 minutes at a temperature of 100 to 200 ° C, preferably under an inert gas atmosphere.

Addition of 3,3'-thiodipropionic acid to epoxides creates a secondary alcoholic group, which is esterified by an excess of 3,3'-thiodipropionic acid, or other epoxide molecules form an etheric bond between the secondary alcoholic group and oxirane oxygen, so the reaction products are ester mixtures and ester ethers having a higher mass, reduced melting point, so that the oxidation stabilizers of the invention are liquid and less volatile than the commercially available 3,3'-thiodipropionic esters hitherto used. They are easier to dispense into polymers and retain stabilizing efficiencies comparable to commercial products.

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The stabilizers according to the invention are prepared by heating the 3,3'-thiodipropionic acid and the epoxide I in a ratio such that each carboxylic acid group comprises between 0.7 and 0.95 gram of oxirane oxygen, preferably in the presence of 0, 1 to 5% by weight (based on the weight of epoxide I) of catalysts such as metal oxides or carbonates II. and a periodic group with aliphatic monocarboxylic acids, for 30 to 600 minutes at a temperature of 100 to 200 ° C, preferably under an inert gas atmosphere.

The following examples illustrate the invention but do not limit it in any way. % and parts given in the examples are by weight.

Example 1

A total of 0.17 kilomoles of pure 3.3 'is charged to a duplicator reactor containing 0.4 kilomoles of 9,10-epoxistearic acid butyl ester (technical product with a mean molecular weight of 350 and an oxirane oxygen content of 4.4%). " thiodipropionic and 0.03 kilomoles of anhydrous potassium formate. In an inert atmosphere and with stirring, the reaction mixture was heated at 170 ° C for 6.5 hours, and at 180 ° C for an additional 3 hours.

After completion of the reaction, the mixture was allowed to cool to normal temperature and stripped under a stream of nitrogen for 40 minutes under a vacuum of 50 psi. The catalyst was removed by filtration.

The resulting liquid stabilizer product contains 3.4% sulfide bonded sulfur, less than 0.1% oxirane oxygen, acid number 0.2. It is a yellowish viscous liquid with a viscosity of 42S mPa. with a density (20 ° C) of 880 kg / m \

Example 2

350 parts of epoxidized propene oligomers (prepared by epoxide of oligomers with an average molecular weight of 350 peroxoic acid) and containing 4.2% oxirane oxygen are heated with stirring under nitrogen blanket with 85 parts of 3,3'-thiodipropionic acid and 4 parts of finely ground calcium carbonate for 8 hours at 160-170 ° C. After cooling to 60 ° C, the catalyst was removed by filtration.

This procedure yielded 420 parts of 3,5-thiodipropionic acid ester, characterized by a content of 3.6% sulfide-bound sulfur and an acid number of 0.1.

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The ester is a viscous, light yellow liquid with a viscosity (20 ° C) of 395 mPa · s and a nusxote of 876 kg / m ³ .

Claims (1)

Object of the invention Esters of 3,3 'thiodipropionic acid prepared by mixing 3 »3' - thiodipropionic acid with epoxides of formula I H (C ^H 2) _n CH - = CH - (CH _{2) m} X (I) wherein NAM 0-18, wherein the sum n + m is from 12 to 36, X is hydrogen or a carboxyalkyl COOC _r H _{2r + 1,} where r is 3 to 5, in a ratio such that each carboxylic acid group contains 0.7 to 0.95 gram gram of oxirane oxygen and by heating preferably in the presence of 0.1 to 5% by weight, based on the weight of epoxide I, of catalysts such as are metal oxides or carbonates XI. of a periodic group or a metal salt of the group of a periodic group with aliphatic monocarboxylic acids, for 30 to 600 minutes at a temperature of 100 to 200 ° C, preferably under an inert gas atmosphere.