CS261729B1 - Dialkylamides of 2-/3-/3,5-dialkyl-4-hydroxyphenyl/ propanamido alkylen dicarboxilic acids and process for preparing them - Google Patents

Description

The invention relates to 2- [3- (3,5-dialkyl-4-hydroxyphenyl) propanamido] alkylene dicarboxylic acid dialkylamides and processes for their preparation.

In order to achieve long-term stability and preservation of the utility properties of polymers, it is essential to use effective stabilizers. application temperature, low cost, suitable dosage form, and colorless. A good stabilizer should meet as many of these conditions as possible. However, meeting all of these requirements is in fact difficult to realize, and thus finding a suitable stabilizer is actually a compromise between reality and this ideal state.

The present invention relates to 2- [3- (3,5-dialkyl-4-hydroxyphenyl) propanamido] alkylene dicarboxylic acid dialkylamides of the general formula I:

o ^{11 11}

-C-NH-CH-C-NH-RJ ( _C h ₂ ) -c-nh-r ₄ o

wherein _r to R ₄ is alkyl of 1 to 24 carbon atoms m is 1 to 12 (I)

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These dialkylamides can be made by the methods of the present invention.

According to a first method of the formula (A), an acid halide is reacted

(A) where R ^, f? ₂ is as defined above, X is halogen, with the dialkyl ester of the acid of formula B

II

H _O N - CH - CO - R c ² i (B) (CH ² ) - C - O - R g ^{2 m 1} o where R g. R g is alkyl of up to 6 carbon atoms, m is as defined above, which is either twice the molar excess over halide A, or is half replaced by trialkylamines or pyridine. The resulting compound of formula C

wherein R @ ₁ , R @ ₂ , R @ 5, R @ 6 and R @ 6 have the above meaning ee further reacted with an amine of formula O

261 729

HgN - R _? (0) wherein R ₇ is R 8 or R ₄ , at temperatures from 20 to 300 ° C for 0.1 to 10 hours.

According to a second method, an acid ester of formula (E) wherein R * is reacted. R ₂ Joint formula

<B)

R1 is as defined above, F is a dialkylamide

II

H _O N-CH-C-NH -R ^(F) _<0 H _{2) m} -C-NH-R ₄

Wherein R 8, R 8 and m are as defined above, at temperatures of 20 to 300 ° C for 0.1 to 10 hours.

AND

The dialkylamides of the alkylenedicarboxylic acids of formula I are highly effective stabilizers for polyolefins. They are potent inhibitors of thermooxidative degradation with long-term stabilizing effect. The nature of their molecular backbone allows them to remain in the polymer matrix for a long time, despite the adverse environmental conditions in which the polymer may be present during its application. They have a strongly suppressed volatility and are relatively very resistant to extraction by both polar (aqueous detergent solution, acetic acid) and non-polar solvents (n-heptane).

Sufficient solubility in the polymer further contributes to the ability to remain in the matrix.

The compounds of formula (I) are solids having melting points generally ranging from 50 to 150 ° C. They are colorless and soluble in toluene, hexane or acetone.

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Their stabilizing efficiencies are comparable to some successful commercial antioxidants, but their resistance to extraction, in particular by n-heptane, exceeds them several times. This is essential for the long-term preservation of the physical properties of the polymer.

The methods by which the compounds of formula (I) may be prepared depend on the type of 3- (3,5-dialkyl-4-hydroxyphenyl) propionic acid which carries the stabilizing function. For acids having a phenolic function shielded to the extent that they do not react with the acyl halide present, both methods are suitable, for acids with a lower degree of steric hindering of phenol, e.g. 3- (3-methyl-5-t-Bu-4-hydroxyphenyl) acid propionic, only the second method is applicable. The first method is most often carried out in an anhydrous solvent without active hydrogen, such as diethyl ether or dioxane. The second method is characterized by an embodiment in the melt at elevated temperature, under a protective atmosphere of an inert gas. However, if desired, this reaction can also be carried out in a high boiling solvent.

The invention is illustrated by the following examples (% by weight).

Example 1:

125 g of 3- (3,5-ditBu-4-hydroxyphenyl) propionic acid chloride (A) dissolved in 400 ml of anhydrous ether was added dropwise to an anhydrous ether solution of 70 g of aspartic acid dimethyl ester (B) and 40 ml with stirring. pyridine. After mixing, the reaction mixture was allowed to stand for 1 hour, then washed with 3 x 400 ml of water acidified with 5 ml of 34% hydrochloric acid. After separation of the aqueous phase, the ether was evaporated. The product obtained was crystallized from toluene-hexane. 50 g of the intermediate thus obtained were heated in the melt with 70 g of octadecylamine (D) at 150 ° C, with stirring under nitrogen atmosphere for 1 hour.

Upon completion, 2- [3- (3,5-ditBu-4-hydroxyphenyl) propanaraidol succinic acid dioctadecylamide (I) was dissolved and crystallized from hexane. It has a melting point of 103-6 ° C, characteristic abeorbent bands in the IR region: phenolic OH 3630 cm ^-1 , -CONH-1 -1

-1675, 1655 cm, -CHg- 2920 cm, is soluble in hexane and toluene

Example 2:

2B1 729 g of 3- (3-methyl-5-t-Bu-4-hydroxyphenyl) propionic acid methyl ester (E) was heated in the melt together with 86 g of β-dodecyl9

Aspartic acid -4-octadecylamide (F) at 150 ° C for 50 minutes, with stirring under a nitrogen atmosphere. After heating, the obtained 2- [3- (3-methyl-5-t-Bu-4-hydroxyphenyl) propanamino] succinic acid 1-dodecyl-4-octadecyl amide product was crystallized from toluene-hexane.

It has a melting point of 78-80 ° C, characteristic absorption bands in the IR region of phenolic OH cm ^-1 , -CONH-1675, 1655 cm ^-1 , -CH ₀ -1 ⁴ 2920 cm, is soluble in toluene and hexane.

Example 3:

Proceeding as in Example 1 was prepared dioctadecyl 2- [3- (3-dodecyl-5-tBu-4-hydroxyphenyl) propanamidoj amber _(Ι β), where instead of (A _g) was used chloride 3- (3-dodecyl-5-t-Bu-4-hydroxyphenyl) propionic acid. Compound (I) thus obtained was added in concentrations of 0.1 and 0.2% to powdered, unstabilized isotactic polypropylene having a flow index of 4. From the prepared film mixture 0.5 mm, they had induction period (IP) values at 130 ° C and a relative reduction in stabilizer content after extraction. -heptane at 25 ° C, shown in Table 1 below. For comparison, the values measured for commercial stabilizer IRGANOX 1010 - pentaerythrityl ester of 3- (3,5-ditBu-4-hydroxyphenyl) propionic acid (II) ).

Example 4:

Following the procedure of Example 1, 2- [3- (3,5-ditBu-4-hydroxyphenyl) propanamido] succinic acid didodecyl amide was prepared wherein dodecylamine was used instead of ( ^D a). The product (1) was tested in the same manner as in Example 3 (Table 1).

Example 5:

In the same manner as in Example 2, 2- [3- (3-methyl-5-t-Bu-4-hydroxyphenyl) propanamido] adipic acid 1-hexyl-4-dodecylamide was prepared, substituting (F _fl ) for

261,729 2-Amino-adipic acid i-hexyl-4-dodecylamide. The product (I) was tested as in Example 3 (Table 1).

Example 6:

Using the same procedure as in Example 2, 2- [3- (3,5-ditBu-4-hydroxyphenyl) propanamido] pimelic acid dioctadecylamide (I.) was prepared using 3- (3,5- ditBu-4-hydroxyphenyl) propionic acid and 2-aminopimylic acid diocta decylamide instead of (F). The product was tested as in Example 3 (Table 1).

Table 1: Stability of polypropylene samples

Claims (3)

I. 2- [3- (3,5-Dialkyl-4-4-hydroxyphenyl) -propanamide] -alkylene dicarboxylic acid dialkylamides of the general formula B * Σ <: 0 0 II II _{(CH2) 2} -C-NH-CH-C-NH-R ₃ (I) of where R ₁ to f? ₄ is alkyl of 1 to 24 carbon atoms; m is 1 to 12 2. A process for producing compounds of formula I according to claim 1, characterized by reacting an acid halide (CH ^ -C-X · II (A) wherein R, R ₂ are as defined above, X is halogen with dialkyl · ester of formula B is H ₂ N-CH c - O-R _£ (B) ° - ^R 6 wherein R., R₈ is alkyl of 1-6 carbon atoms and m is as defined above, which is either in double molar excess to halide A or is replaced in half by trialkylamines or pyridine and the resulting compound of formula C 0 0 II II (0Η _{2) 2} -0-CH-NH-COR ₅ ^<σΗ 2 \ ^η-θ- θ - ^Ε 6 (C) 261 729 where R ₁ , F? ₂ , f? ₅ , R 8 and m are as defined above, further reacted with an amine of formula D h ₂ n - R ₇ where R y is R 8 or R ₄ at temperatures from 20 to 300 ° C for 0.1 to 10 hours. Process for the preparation of the compounds of the formula I according to claim 1, characterized in that an acid ester of the formula E is reacted wherein R 1 _and R 6, R 6 are as defined above with a dialkyl amide of the formula F II H _O N - CH - C - II H - R ^{2 3} (P) Wherein R 8, R 8 and m are as defined above at temperatures of 20 to 300 ° C for 0.1 to 10 hours.