DE2237849A1 - AMINE SALT OF 3,5-DIALKYL-4-HYDROXYPHENYL CARBONIC ACIDS AND THEY STABILIZED POLYAMIDE COMPOSITIONS - Google Patents

Description

Dr. F. Zu.TiBtelr «se-n. - Dr. Ξ. Assmann Dr. R. Koenlgsberger - Dlpl.-Phys. R. Holzbauer - Dr. F. Zumsteln Jun.

PATENT LAWYERS

TELEPHONE: COLLECTIVE NO. 225341

TELEX 529979

TELEGRAMS: 2UMPAT CHECK ACCOUNT: MUNICH 91139

BANK ACCOUNT: BANK H. HOUSES

8MUNICH2.

BRÄUHAUSSTRASSE 4 / lil

Case 3-7662 / GC 553
12 / R

CIBA-GEIGY AG, Basel / Switzerland

Amine salts of 3> 5-dialkyl-4-hydroxyphenylcarboxylic acids

and polyamide compositions stabilized therewith

The invention relates to amine salts of 3 »5-dialkyl ~ 4 ~ hydroxy ~ phenylcarboxylic acids and the use of these compounds in the manufacture of synthetic polyamide compositions with improved thermal and oxidative stability.

The amine salts of 3,5-dialkyl-4-hydroxyphenylcarboxylic acids according to of the present invention are represented by the general formula

Il -

NiU

(I)

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shown in which

1 2

R and R, which can be the same or different, are alkyl groups with 1 to 4 carbon atoms, preferably are tert-butyl groups,

R is an alkyl group having 1 to 5 carbon atoms, preferably is a methyl group,

y represents the value of 0 or 1,

m has a value from 0 to 2 when y represents the value 0 and has a value 2 when y represents the value 1; preferably m takes the value of 2,

χ has a value from 2 to 6, preferably 6 and

ζ has a value of 1 when y represents the value of 1 and has a value of 2 when y represents the value 0.

Illustrative examples of alkyl groups represented by R and

R are methyl, ethyl, propyl, isopropyl and t-butyl groups. The preferred groups are methyl groups and the branched alkyl groups such as t-butyl and isopropyl groups.

The alkylenediamines which form the compounds according to the invention are used contain 2 to 6 carbon atoms. The most preferred alkylenediamines are ethylenediamine and n-hexanediamine.

The compounds according to the invention with the above general Formula I can by adding an alkylenediamine of the formula

NH ₂ - (CH ₂ ) _X -NH ₂

to an alcoholic solution containing the corresponding 3,5-di-

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alkyl-4-hydroxyphenylcarboxylic acid of the formula

contains.

The desired product, which precipitates out of the solution, can be recovered by filtration.

The 3,5-dialkyl-4-hydroxyphenylcarboxylic acid component of the formula I, in which m = 1, can be obtained, for example, by chloromethylation an alkyl phenol as in the U.S. patent.

2 838 571 ", followed by treatment with sodium or potassium cyanide and hydrolysis of the dialkylhydroxyphenylacetonitrile obtained, getting produced. The acid in which m = 2 can be prepared according to the US Pat

3 247 240 methods described are produced while the acid, in which m = 0, prepared according to the methods described in Belgian patent 6,804,624 will.

The amount of the compounds of the invention that are in the polyamide incorporated can be in the range from 0.01 to 1.0 wt. $, based on the polyamide, but preferably in the range from 0.05 to 0.5 wt. $ can be incorporated. After a preferred embodiment of the present invention the polyamide also a common matting agent, titanium dioxide; Light stabilizers like manganese compounds! and coloring materials such as dyes and and pigments.

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With synthetic polyamides are condensation polymers meant by polycondensation of aminocarboxylic acids or Mixtures of diamines and dicarboxylic acids are obtained, including the mixed polyamides obtained by polycondensation can be obtained from mixtures of different polyamide-forming components. The expression refers more specifically to the class of polyamides commonly known as nylons, from the polyhexamethylene adipamide and PolyeaproIactarn are known examples. In this class Mixed polyamides are also included, for example by polycondensation of a mixture of hexamethylene diammonium adipate can be obtained with caprolactam.

The present invention is useful for polyamides in all. To shape. Particularly preferred are the polyamides that are fibrous Form by melting, spinning the molten material and stretching the filaments obtained in a conventional manner can be produced. Polyamides particularly suitable for the present invention are those in which the polyamide Is polyhexamethylene adipamide.

The stabilizers according to the invention can be incorporated into the polyamide be incorporated before, during or after the polycondensation step. That way you can use the stabilizers too the polymer-forming components before the polycondensation stage or can be added during the polycondensation process and the reaction can be completed by heating will. The stabilizers can also be added to the ready formed polyamide by adding to the molten one Polyamide or alternatively they can be mixed with the solid polyamide or the solid polyamide can be in mold of pieces, pellets or shavings are coated with the stabilizer, whereupon the polyamide is melted. the preferred embodiment for incorporation during the polymerization is the addition of the stabilizer just before the polycondensation reaction of the monomers. It is

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It is important that the stabilizer is evenly distributed throughout the melt »

The following examples serve to illustrate the invention. The percentages relate to weight.

example 1

1,6-Hexanediainmonium "bis (3 ^ - di ~ t-butyl-4'-hydroxyphenyl) - ° propionate

To 5.56 g of 3- (3,5-di-t-butyl-4-hydroxyphenyl) propionic acid in 20 ml of isopropanol were 1.16 g of hexamethylenediamine in 5 ml of isopropanol joined. The crystalline product precipitated immediately and the product was filtered, washed with isopropanol and dried. The product had a melting point of 102 ° C -103 ° P «

Nitrogen content: calculated $ 4.16

found? $ 4.08

Similarly, the following 3j> 5-dialkyl-4 ~ 'replaced hydro3cyphenol carboxylic acids in an equivalent amount the 3 $ 5-di-t-butyl-4 ~ hydroxyphenylpropionic acid ί

(a) 3,5-Di ~ t-butyl-4-hydroxypheny / acetic acid

(b) 3> 5-di-t-butyl-4-hydroxyphenylbenzoic acid

(c) 3-methyl-5-t-butyl-4-hydroxyphenyl propionic acid

(d) 3,5-dimethyl-4-hydroxyphenyl propionic acid

This is how mani

(a) 1,6-Hexanediammonium-bis- (3,5-di-t-butyl-4-hydroxy- phenyl) acetate "

The product melts with decomposition at 189 ^° C. nitrogen content β calculated s 4 ₉ 4-5 i ^a

Geflindens 4 »57 ^

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(b) 1,6-Hexanediairanonium bis - (3,5-di-t-butyl-4-hydroxybenzoate)

Melting point 198 ° C-200 ° C

Nitrogen content: calculated: 4.34 9 ^

found: $ 4.28

(c) 1,6-hexanediammonium bis (3-methyl-5-butyl - 4-hydroxyphenyl) propionate

(d) 1,6-hexanediammonium bis (3, -5-dimethyl-4-hydroxyphenyl) propionate

Example 2

1,6-hexanediammonium-2-methyl-, / 2- (3 ♦ 5-di-t-butyl-4-hydroxyphenyl) -glutarate 7

(a) A reaction flask was charged with 94.3 g of acetaldehyde and 260 g of acetic acid and cooled to 20 ° C. HCl gas was bubbled through the solution for 35 minutes, after which 256.5 g of 2,6-di-tbutylphenol in 130 g of acetic acid was added over 1 hour. After this addition, the solution was ^{stirred for 90 minutes at 25 °} C. and the addition of HCl gas was continued until 100 g of HCl were contained in the reaction mixture. The mixture was then cooled to -5 ⁰ C, and 130 g of concentrated aqueous HCl were added to clear the reaction. The mixture was poured into a separatory funnel and the aqueous phase was separated. The organic phase was then diluted with 300 ml of heptane and washed very well with water and saturated sodium chloride solution. The organic phase was dried with magnesium sulfate, evaporated and dried in vacuo to constant weight. The 1-chloro-1 - (3 »5-di-t-buty. '* .- ^ - hydroxyphenyl) ethane was obtained in 92% yield.

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(b) To 97.7 g of potassium yanide dissolved in 272 ml of water. warden joined 94-5 ml of acetone and the solution was heated to 45 ⁰ C. 251 g of 1-chloro-1- (3 »5-di-t-butyl-4-hydro3cyphenyl) ethane, dissolved in 190 ml of acetone, were added to this solution over a period of 30 minutes. The reaction mixture was stirred for a further 30 minutes "at 45 ^{0 C and then cooled to 10 0} O" Me reaction mixture was added to 1400 ml of water ₉ whereupon the organic liquid layer was separated and taken up in ether "The ethereal solution was washed with water over magnesium sulfate "wherein a viscous oil which was dried and evaporated to dryness * distilled in Yakuum in a temperature range between 195 ⁰ C and 25O ⁰ C at a pressure iron 0.5 to 0.7 mm. the product, 1- ( 3i5-di-t-toutyl-4-hydroxyphenyl) -1, -methylacetonitril _i} was recrystallized from heptane and had a melting point of 102-107 ⁰ Co

(c) To 38.9 g of 1- (3,5-di-t-butyl- 4-hydro3cyphenyl) -1-methylaeetonitrile were added 80 g of tert-butyl alcohol, 1.5 g a 30% aqueous potassium hydroxide solution and 8.2 g of acetonitrile in 10 g of tert-butyl alcohol and the reaction mixture was stirred for 20 hours at room temperature and then heated under reflux for 5 hours. The product, 2- (3.5 -di-t ~ butyl-4-hydroxyphenyl) ~> 2-metliylglutarQ "nitrile was prepared from the reaction mixture with 100 ml of an aqueous acetic acid 10bigen precipitated filtriertj washed with water and dried. the product had a melting point of 108-110 ⁰ C. After Umkr:
Melting point 114-116 ° C.

was from 108-110 ⁰ C. After recrystallization from hexane, the

(d) A reaction flask was charged with 5 »2 g of 2- (3,5-di-t-butyl-4-hydroxyphenyl) -2-methylglutaronitrile and 50 ml of ethylene glycol and heated to 120 ° C. To this solution 32 g of sodium hydroxide (50 wt. $ Aqueous solution) added and the mixture was heated a further 3 hours at 125 ⁰ -130 ° C. After cooling, the reaction mixture was poured into 1 liter of water, acidified with hydrochloric acid, and the product was filtered off and dried. The product, 2-methyl- / S- (3.5 ~

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di-t-butyl-4-hydroxyphenyl) glutaric acid / was recrystallized from aqueous ethanol and had a melting point of 208 21O ⁰ C.

(e) To 2.1 g of 2-methyl- / 2- (3,5-di-t-butyl-4-hydroxyphenyl) -glutaric acid /, dissolved in 15 ml of isopropanol, there were 0.7 g of hexamethylenediamine added in 5 ml of isopropanol. The product crystallized from solution, was filtered and washed with isopropanol washed. The product was further slurried in ethyl ether, filtered and dried; it had a melting point from 215 ° -217 ° C.

Example 3

To 39.3 g (0.15 mol) of hexamethylene diammonium adipate were Hexamethylendiammoniumdlacetat (the theoretical yield Nylon 0.5 f ') joined various inventive compounds for molecular weight control and 0.183 g 0.177 g (Molj ° i5 mole percent 7,5 χ 10). The mixtures were mixed thoroughly and placed in Pyrex polymerization tubes.

The polymerization tubes were evacuated three times and each time filled with highly purified nitrogen. The polymerization tubes with a continuously maintained slight positive nitrogen pressure were placed in a salicylic acid methyl ester steam bath at 222 ^° C. The nylon 6,6 salt melted to form bubbles due to the release of water. After the blistering had ceased, a clear melt was obtained which solidified after 5-8 minutes. After 1 hour at 222 ⁰ C the Polymerisationsrohre were placed for 1 hour in an o-phenyl-Phenolbad of 285 ⁰ C, where the solid melted gradually again. The polymerization tubes were kept in the steam bath at 285 ^° C. for an additional 1/2 hour, while they were kept under an oil pump vacuum (1 mm). Highly purified nitrogen was then fed in again and the polymerization tubes were allowed to cool.

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The stabilized Nylon 6,6 was "milled at room temperature in a Wiley mill. Approximately 2 g were dissolved in a small petri dish in a convection glass rotary kiln" at 140 G ⁰ 65 hours heated. The viscosities of 1% sulfuric acid solutions of aged and non-aged polymer samples were determined at 25 ^° C. The effectiveness of the stabilizers was assessed by the percentage retention of the specific viscosity and by the color formation after oven aging. A polyamide that did not contain stabilizers was prepared and tested in a similar manner; the percent specific viscosity retention results are compared in Table I below. The stabilized polyamides showed a better percentage retention of the specific viscosity and color fastness than the non-stabilized polyamides after oven aging.

Table I.

Polyamide percentage retention

the specific viscosity

not stabilized 64

1, o-hexanediammonium bis - ^^ - di-tbutyl ^ -hydroxybenzoate) 67

1,6-hexanediammonium bis (3,5-di-t-butyl-4-hydroxyphenyl) acetate 79

1,6-hexanediammonium bis (3,5-di-t-butyl-4-hydroxyphenyl) propionate 86

1, ö-hexanediammonium-2-methyl- ₍ / 5- {3 »5-di-butyl-4-hydroxyphenyl) -glutarate7 77

') 0 \) S 0 7/1 3 BB

Example 4

Pellets (500 g) of unstabilized nylon-6,6 (Zytel 101, DuPont) were placed in a kitchen blender. While mixing, a solution of 2.5 g (0.5 $>) 1, o-hexanediammonium-bis-OtS-di-t-butyl ^ -hydroxyphenyl / propionate in 20 ml of water was slowly added. The stabilized pellets were dried for 4 hours at 80 ° C. and <1 mm.

The polyamide formulation was extruded at 316 C (600 P) through a 0.64 cm (1/4 inch) die into a rod which was water cooled and cut into pellets. A 1.91 cm (3/4 inch) Brabender extruder equipped with a nylon screw was used. The pellets were dried for 4 hours at 80 ^° C. at <1 mm.

The dried pellets were cm (5 x 5 x 0.005 inch) pressed into films of 12.7 x 12.7 x 0.0127 at 290 ⁰ C and 24.6 kg / cm ² (350 psi) for 3 minutes.

The mold was quickly transferred to a water-cooled press and held at 24.6 kg / cm ² (350 psi) for 2-3 minutes.

2.2 g samples of the compression molded nylon 6,6 films were made aged in a circulating air rotary kiln at 150 C for various times. The performance of the stabilizers was measured by measurement the retention of specific viscosity of oven aged samples in 11% formic acid solution. the The time until the 50% retention of the specific viscosity is shown in Table II below:

Table II

i * Amine salt - from hindered hours to 50% by-phenolic carboxylic acid retention of the specific

viscosity

1,6-hexanediammonium-bis-

(3,5-di-t-butyl-4-hydroxy-91

phenyl) propionate

without 15

309 RO? / I 30 6

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Example 5

1,6 ~ Hexanediammonium bis (3,5-di-t-butyl-4-hydroxyphenyl) propionate was added in an amount of 0.5% by weight to dry nylon 6 granules, and the mixture became direct spun into 20 denier filaments. Samples of the single threads wound into a strand were ^{aged in an oven at 165 °} C. for 24 hours. The stability of the nylon 6 filaments was determined by the specific viscosity of 1% sulfuric acid solutions. The following results for the retention of the specific viscosity were obtained;

not stabilized 31 #

1,6-hexanediammonium bis (3,5-di-t-butyl-4-hydroxyphenyl) propionate 72 fo

Example 6

0.5% (based on the substrate) of the salt of 1,6-hexamethylene diamine and 35-di-tert-butyl-4-hydroxyphenyl propionic acid (Example 1) were sprayed onto dry nylon 6 granules and this mixture was spun directly through an extruder into 20 denier filaments.

Strands were produced from the drawn single threads ^{and aged in a compressed air oven at 165 °} C. for 24, 48, 72, 96 and 120 hours.

The viscosities of the solution and the mechanical strength were determined after each oven aging time and the results evaluated graphically.

Tabel

0 hrs. 24 hrs. 48 stan. 72 hrs. 96 hrs. 120 hrs. 2.60 2.15 1.87 1.71 1.62 1.59

3.09807 / 13 86

Claims (11)

Claims 1 2
wherein R and R, which can be the same or different, Represent alkyl groups with 1 to 4 carbon atoms, R represents an alkyl group with 1 to 5 carbon atoms, y represents the value of O or 1, m has a value from O to 2 when y = Q and has a value of 2 when y = 1, χ has a value from 2 to 6 and ζ has the value of 1 if y = 1 and the value of Has 2 if y * Q 2. A compound according to claim 1, characterized in that 1 2
R and R are tert-butyl. 3. A compound according to claim 1, characterized in that R ¹ and R is tert-butyl, R is methyl , y is the value of Has O or 1 , m has the value 2, χ has the value 6 309807/1 386 ζ and the value of 1, has when y = 1 and the value of 2 when y = 0th 4. 1,6-Hexanediainmoniuffi-2-ynethyl- ^ 2 ~ (3,5-di-t-butyl-4-hydroxyphenyl) -glutarate /. 5. 1,6-hexanediaimionium bis (3,5-di-t-butyl-4-hydroxyphenyl) propionate. 6. 1,6-hexanediammonium bis (3,5 ~ di-t-butyl-4-hydroxybenzoate) 7. 1,6-Hexanediaimonium bis (3,5-di-tert-butyl-4-hydroxyphenyl) acetate. 8. A process for the preparation of the compounds according to claim 1, characterized in that there is an alkylenediamine of the formula () -NH ₉ with a carboxylic acid of the formula «Ο— <() V- (C) j- C ₁ H _21n -COOH COOH ^{1 (2} : implements, 9. Use of the compounds according to claim 1 for stabilization of polyamides, which are normally subject to oxidative degradation. 10. Use according to claim 9, characterized in that as stabilizer a compound according to claim 2 USAGE-r det. ₍ 30 9807/1386 11. Use according to claim 9, characterized in that a compound according to claim 3 is used as a stabilizer. 309807/1386