DE1907403A1 - New asymmetrical diaryloxalamides and their use as stabilizers and UV absorbers for plastics - Google Patents

Description

PaTentanwafte
Dr. W. Schalk, Dipl.-Ing. P. Wirth

Dipl.-Ing. G. Dannenbcrg
_Λ Dr. V. Schmiad Kov / arzik

Case 2859 Dr. P. Wdnhotd, Dr. D. Gudel February 13, 1969

6 Frnnkf urt / M., Gr. Eschenheimer. Sir, 35 * SK / Tr .

SANDOZ AG
Basel, Switzerland

" New asymmetrical diaryloxalamides and their use as stabilizers and UV absorbers for plastics ^w

It is known that certain asymmetrical diaryloxalamides can be used as UV absorbers for plastics. However, the known compounds of this class are either in the plastics, in particular the polyolefins relatively poorly soluble, or they contain one or more high molecular weight organophilic radicals, their hydrocarbons the remainder contains more than 8 carbon atoms, which reduce the effectiveness of the diaryloxalamides.

It has now been shown that by using certain starting materials for the production of asymmetric diaryloxalamides to compounds that even without the presence of higher molecular weight, more than Containing 8 carbon atoms in the hydrocarbon residue organophilic residues in their molecule that reduce the effect, good solubility in plastics, in particular in polyolefins.

909840/1786

The present invention relates to a process for the preparation of compounds of the formula I.

^R 5 ^R 6

NHCOCONH

where ji Ro * R - ** Rji * Rc *

R «7

_n ^H _2n -l *

H, Cl, Br, aryl, alkylaryl, -C _n H _{2n + 1}

-QC H ", and -O-aryl, and in which
η 2η + 1 ^Ί

m is an integer from l-o and

η denotes an integer from 1-4, whereby not all radicals R ^, Rg, R- ,, R ^, R ^ * Rg * R ^ - ^{un (} i Rg »among each other and η need not be the same in all radicals , and wherein the aryl and aralkyl radicals contain no more than 8 carbon atoms, which is characterized in that 1 mol of a compound of the formula II is used simultaneously or in succession for 1 mol of oxalic acid or 1 mol of a functional derivative thereof

909840/1766

II.

x ^H 2x + l

wherein χ denotes an integer 1-8 including 0 and 1 mol of a compound of the formula XXX

III.

^R 8 ° n ^H 2n + l

can act so that an amidation as complete as possible the oxalic acid or the functional derivatives of the same

# man /
follows, and that the product thus obtained is alkylated with alkylating agents containing the radical - CH ₀ ^ _n , if present

m dm + χ

phenolic hydroxyl groups are included.

The compounds obtained in this way are very stable to the action of heat and combine the property of optimally absorbing UV rays and making them easily soluble in polyolefins be.

Examples 1 and 2 below explain two specific examples Cases how the diaryloxalamides of the formula I can be prepared, wherein the temperatures in degrees Celsius and the Quantities are given in parts by weight.

909840/1768 BATH

Table 1 which follows Examples 1 and 2 lists a whole series of compounds which can be prepared by the method given in Examples 1 and 2. The products manufactured by this method can be incorporated into plastics in raw or purified form. The plastics containing such auxiliaries in amounts of 0.1-0.5 % of their weight are protected against heat, and in particular against UV rays. Polyethylene press plates, which contain such stabilizers in an amount of 0.1-0.5 % , are clear and protected against the damaging effects of UV rays.

In Examples A-D it is indicated in which way the mentioned Stabilizers can be used. — In the table 2 a number of diaryloxalamides and their properties are given for comparison, which do not fall under the formula I. In both tables, E is the molar extinction coefficient. This was with .light of the wavelength / at an alcoholic Solution of the oxalamide measured. y (is also the most strongly absorbed wavelength in tnu.

The solubility of the oxalamides in alcohol (ethyl alcohol) and gasoline (bp 100-120 ·, D ^ ⁰ 0.727) was determined at 20-22 ° in mg per liter.

909840 / $ 176

BATH ORIGINAL

example 1

Production of o-ethoacy.-o'-ethyl oxalic acid bis-anilide

OC ₂ H ₅

(0 / UHCOCOOO ₂ H ₅ OC ₂ H ₅

¹¹ · ^ / - NHCOCOOC ₂ H ₅ + HgN

OC ₂ H ₅

C ₂ H ₅

NHCOCONH

OC ₂ H ₅ C ₂ H ₅

IO-phenetidine and oxalic acid diethyl ester are initially charged in a molar ratio of 1: 2. The catalyst is given per mole Amine about 5-4 ml of BF, -Aetherat and heated with stirring to 130 * C (bath temperature) · After a short time, solution occurs

. . a. With the beginning of the ethanol return flow, the mixture becomes Remove the ethanol under vacuum (approx. 200 mm Hg) and continue for 1 1/2 hours at the same temperature touched. The dark brown solution obtained in this way is still oa. 10 minutes with dye bungalow at the same temperature

909840/1766

stirred further and then sutured with the addition of a filter aid.

The excess diethyl oxalate is then distilled off under reduced pressure. The ester amide obtained in this way crystallizes on cooling completely off. F 65-71 * C Yield: 85-90 #

Recrystallization from alcohol gives the colorless, pure product of p. 76-77 * 0

For the conversion with further amines, however, the crude product be used·

II · The ester amide prepared above and 2-ethylaniline are heated for 4 hours at 170 ⁰ C (bath temperature) in molar amounts, with the addition of little BF, etherate. The alcohol formed is removed during the reaction under reduced * pressure (200 mm Hg). When the reaction is complete, the resulting dark pulp is poured into a bowl and allowed to cool, * whereby a hard mass is formed, which is first crushed and then mixed with alcohol in a mortar finely rubbed, sanded and washed with alcohol. The crude product obtained in this way melts at 121-1> 1 ° C. Recrystallization from benzene leads to pure, colorless o-ethyloxy-o'-ethyl-oxalaKure-bia-anilide.

Fp. 119 * 121 * 0 Auebeut · f oa. 65 % 909640/1766

Example 2

By using o-aminophenol instead of o-phenetidine in example 1, the compound is obtained

NHCOCONH

1 mol of this compound is heated to 55 ° for 60 hours with stirring together with 25 mol of acetone, 1.5 mol of potassium carbonate and 1.2 mol of n-hexyl bromide. The acetone is then distilled off in vacuo, the residue is washed several times with water and recrystallized from alcohol. The compound is obtained

NHCOCOMH

°° 6 ^Η 13

*? in about 90 # yield as white crystals of melting point 71-72 ° o · The absorption maximum of an alcoholic Lo

The solution is 500-310 ιψ, the extension coefficient is o> 13700. At 20 ° in alcohol there are oa. 16.5 gr. / Liter and in petrol

oa. 23 g / liter soluble.

Table T

Constitution '

Solubility ia alcohol gasoline

CH.

OCH, CH _x 3 3

152-153 ° 300 12400 1900 2100

^ HKC0C0KH (o) 143-145 ° ^ 300 14200 1700 1250

^0CH 3 ^C 2 ^H 5 "X-

• ^ Λ IiKCOCOHH fo) 132-135 ° 300 14700 3900 5000

Oc ₂ H ₅₁ C ₂ H ₅ -:. ·; · .. ·;.: -

► SiHCOCOaH ^ -CH ₃ 133-135 ° 302 .15500 2400 2400

OC ₂ H ₅

CH,

137-138 ° 302. 15β00 2240 2300

OC ₂ H ₅ .

117-118 ° 505 · '; 12400

OC ₂ H ₅ C ₂ H ₅

4100 * 4500

90984Ό / 1766

Portion of table I

constitution

Solubility in alcohol gasoline

100-104 ° 320 9600 6000 6400

H ^ CO

118.1190 320 '. 10400

C ₂ H ₅

71-72 ° '300 1270. I6500 22000

70-72 ° ■ "·· 300 I3OOO I6OOO 21000

90 9 8 ^ 0/1766

.... BAD ORIGINAL

Table 2

Constitution Solubility in ■ • Alcohol Gasoline

HHCOCONH

5 CH ₃ 260-261 «278 12500 82

KHCQCOHK

185-184 · 276 12800 450

400

«Hcocohh föS.

OCH ₃ OCH ₃ 252-252 ° 305 16800. .53 80

CH,

►XHC0C0HH < OCH ₃ OCH ₃ 267-269? ·· ·. 295-20000.? · ·

227-229 / '315 16800 150

140

JiUCOCOHH ^ N

OC ₂ H ₅ 173-174 · · 310 · "18100

909840/1766

BATH ORIGINAL

Table 2 continued

constitution

Solubility in alcohol gasoline

«IlCCCOßK

' ² 5; 268-269? .295. .2O9OO · 4 .24

^ \ HUCOCOKH,
OC ₂ H ₅

CH ₅

OC ₂ H ₅

ti 184-186 ° 315 16 800 100 150

^ÖBC0MllU \ Q / " ^c iL ^H a ·

205-207 ° 287 2I8OO 80

187-188 °. .298 17400 500

OCH,

, -I63 ⁰ ..-. / 304 18600.675 105

COOCHj COOCH ^ 251-252 ° ..: 315 '20100 50

OCH, COOCH 188-190 ° 315 I77OO 400 130.

3. · · ..-. .. "XJ -.- .; 90 9840/17; 6.6 ■ ''<

BATH

Portion of table 2

constitution

Solubility in alcohol gasoline *

COOCH.

188-I ₉ O *

18400 190

15:

• Cl Cl

202-205 ° '280 17000. 150

Cl

. I.

180

297-298 ° 280 225OO

KKCOCQHH

Cl OCH,

'Cl ei OCH-

I97-I99 ⁰ '. 5OO I45OO - 500 400

171-172 ° 290, I65OO. ' /.· 590 140

150-I5I ^0. · 290 ..17400

_{215 2l6} o

520 500

590

60

187-188 ··;. '298' -17400

.500

JiUCOCOXHQ

122-125 ° 508 I67OO 65O 'I52O.

Application examples

A.) Polyethylene is in a suitable niche at 150 ° with 0.2 % of its weight of the compound

NHCOCONH OCH,

mixed and then pressed into plates 0.25 mm thick.

B.) Polypropylene is used in the usual way at ΐ8θ · with 0.1 Qewiohts-Jt of the connection. i

, 0- \ O> NHCOCONH

₂ H ₅

mixed and pressed into sheets 0.3 mm thick. To These plates are 200 hours of exposure in the fadeometer still unchanged, while tin · corresponding plate without Zusati has hairline cracks and is brüohlg Sin

909840/171 *

BAD ORIGINAL?:

Signed stabilization of the polypropylene is obtained if, in addition to 0.2% of the above oxalamide, 0.5 % of dilauryl thiodipropionate C- ^ gHgj-OOC-CgH ^ -S-CgH ^ -COOC ^ Hg, - is added will. Particularly effective as co-stabilizers are nickel salts or complexes such as nickel stearate; further also sterically hindered phenols such as 2,6-di-tert-butyl-4-methyl-phenol.

C.) 0.5 % of the compound

NHCOCONH

OC,

C ₂ H ₅

are incorporated into polyvinyl chloride at Ι8θ. Plates produced therefrom by pressing show no change after 2000 hours of exposure in the Xenotest. By measuring the UV absorption in unexposed and exposed samples, it can be determined that the Consentration of the UV absorber still practically unchanged is.

909840 / $ 171

D.) A commercially available nitro lacquer is used for 5 % of the compound

NHOOCONH -vO °° 6 ^H 15

to. Fir wood, which was painted with this varnish, does not darken in the light after a long time In contrast to patterns, which do not contain the above addition.

909840/1766

BATH ORIGINAL ' E.) Polyethylene is 0.3 % of the compound

t-C

4 ^H 9

NHCOCONHr (O

OC

2 ^H 5

t-C

£ 0.4 of the connection

CH,

CH.

HO

t-C

4 ^H 9

OH

t-C

4 ^H 9

and 0.2 # tri-nonylphenyl-phosphate mixed at 180 ° and pressed to 0.2 mm thick panels · These prove to be very good against light, heat and oxidation protected·

9098.40 / 1766

BAD ORfQfNAi.

Claims (5)

Patent claims: H, Cl, Br, aryl, alkylaryl, -C _n H -0-CH _{2n + 1} and -O-aryl, and wherein m is an integer from 1-8 and η mean an integer from 1-4, not all and R _Q with each other Radicals R ₁ , R ₂ , R ,, R ^, Rc t Rg, and η do not have to be the same in all radicals, and the aryl and aralkyl radicals contain no more than 8 carbon atoms 2. A process for the preparation of the compounds according to claim 1, characterized in that 1 mole of oxalic acid or 1 mole of a functional derivative thereof is used simultaneously or in succession 1 mole of one Compound of formula II II. wherein χ is an integer 1-8 including O. and 1 mole of a compound of formula III - NH, III. ° n ^H 2n + 1 allowed to act in such a way that the most complete possible amidation of the oxalic acid or the functional derivatives thereof takes place, and that the product thus obtained is treated _{with alkylating agents which contain the radical - O 1n} Hp _{1n + -I} alkylated if it contains phenolic hydroxyl groups.
«. 3. The method according to claim 2, characterized in that the starting materials are chosen so that compounds of formula I are formed in which R ₁ , R £ »R * and Rg are hydrogen, R- hydrogen, methyl, methoxy or - 3 _ 90904f / $ 178 BATH Ethoxy, Rg and Rr, hydrogen or methyl, m 1-6 and η 1 or 2 mean. 4. The use of the diaryloxalamides of the formula I for Stabilization of plastics, especially polyolefins. 5. The use of the diaryloxalamides according to formula I in combination with conventional plastic stabilizers, especially sterically hindered phenols, sulfur-containing compounds, tin compounds, phosphorus containing compounds, as well as metal salts or complex · The patent attorney: ίίί Ka ^ J- 909840/1766