DE3426367A1 - Novel phenothiazine derivatives, process for their preparation, and their use as stabilisers for plastics prepared by the polyisocyanate polyaddition process - Google Patents

Abstract

The invention relates to novel phenothiazine derivatives, to a process for their preparation, and in particular to the use of phenothiazine derivatives, preferably liquid at 20 DEG C, of the formula <IMAGE> in which R<1> and R<2> are identical or different and are hydrogen, halogen, an alkyl, alkoxy or alkylmercapto group having 1 to 18 carbon atoms, or an optionally substituted phenyl radical, R<3> is hydrogen or a methyl, ethyl and/or methylol radical, n is an integer from 1 to 20, and m is an integer from 3 to 12, as stabilisers, preferably against UV radiation and thermal degradation, for plastics prepared by the polyisocyanate polyaddition process, preferably compact or cellular polyurethane polyurea elastomers.

Description

SASF Aktiengesellschaft 0. Z.

New phenothiazine derivatives, processes for their preparation and their Use as stabilizers for after the polyisocyanate polyaddition process manufactured plastics

According to US Pat. No. 2,786,080, polyoxyalkylene polymers having molecular weights of at least 250 stabilized with phenothiazine.

For stabilizing polyurethanes based on polyether poly oils are according to US Pat. No. 3,468,842 with alkyl, alkoxy, alkyl mercapto groups or halogen-substituted phenothiazines are used.

Disadvantages of the phenothiazine derivatives and phenothiazine described is their incompatibility with polyurethanes. The products migrate to the surface of the molded body and are deposited there as a light gray film, which reappears after a short time even after cleaning the body of the shape. The stabilizer effect was attributed to the fact that the phenothiazine or the phenothiazine derivatives accumulate on the surface of the molded body and act there as an antioxidant.

It is also known from Acta Chem. Scand. 6, pages 310-311 (1952) the Production of 10- (ß-Hydroxyethyl) -, 10- (ß-Hydroxypropyl) - and 10- ("J ^ hydroxypropyl) -phenothiazine.

The object of the present invention was to provide stabilizers, in particular against UV radiation and thermal degradation, for plastics manufactured using the polyisocyanate polyaddition process. The stabilizers should be well compatible with the starting components, so that no sediment formation occurs during normal storage times, and they do not diffuse out of the polyurethane moldings and become superficial deposit.

Surprisingly, this object was achieved through the use of N-oxyalkylated and / or N-hydroxyalkyl-substituted phenothiazine derivatives be dissolved as stabilizers.

The invention thus relates to the use of phenothiazine derivatives of the formulas

BASF Aktiengesellschaft -t- OZ 0050/37230

S N- (CH ₂ CHR ³ -O) _n -H 05

in which

r1 and r2 are identical or different and are hydrogen, halogen, preferably chlorine and / or bromine, an alkyl group with 1 to 18, preferably 1 to 10 carbon atoms, an alkoxy group with 1 to 18, preferably 1 to 4 carbon atoms, an alkyl mercapto group with 1 to 18, preferably ■ mean 1 to 4 carbon atoms or an optionally substituted phenyl radical,
Rr is hydrogen, a methyl, ethyl and / or methylol radical, η is an integer from 1 to 20, preferably 2 to 5 and m is an integer from 3 to 12, preferably 3 to 6, as stabilizers for after the polyisocyanate Polyaddition made plastics.

The invention also relates to new phenothiazine derivatives of the formulas (I) and (II), in which R, Rj R ^, η and m have the meaning given above have, with the exception of lO- (ß-hydroxyethyl) -, lO (ß-hydroxy-propyl) - and 10- (• / ■ '-Hydroxypropyl) -phenothiazine and

a process for the preparation of phenothiazine derivatives of the formula (I), in the Rl, r2, R ^ have the meaning given above and η equals 2 to 20 which is characterized in that optionally substituted Phenothiazines in the presence of basic catalysts with 2 to 20 moles of alkylene oxide from the group consisting of ethylene oxide, 1,2-propylene oxide, 1,2-butylene oxide and glycidol or mixtures of at least 2 of the alkylene oxides mentioned are oxyalkylated.

BASF Aktiengesellschaft - "3 - 0.Z. 0050/37230

The polyoxyalkylene radical according to the invention, optionally substituted phenothiazines of the formula (I) with the other starting components, in particular polyether polyols, more compatible with the production of plastics by the polyisocyanate polyaddition process and the Systems more stable in storage. Often are crystalline, optionally substituted Phenothiazines are liquefied by polyoxalkylation and are therefore easier to dose and process at room temperature. Surprisingly it has also been found that the optionally substituted phenothiazines of the formulas (I) and (II) show a very good stabilizer effectiveness, although the phenothiazine derivatives are bound homogeneously distributed in the plastic via polyurethane groups and have an increased concentration of the Molded body surface is prevented and exudation is prevented.

Phenothiazine in particular is used to prepare the phenothiazine derivatives of the formulas I and II which can be used as stabilizers according to the invention. However, mono- and / or disubstituted phenothiazines are also suitable. The following may be mentioned as substituents: alkyl groups such as methyl, ethyl, n-propyl, isopropyl, η-butyl, sec-butyl, tert-butyl, pentyl, hexyl, 2-methylhexyl -, 2-ethylhexyl, 2,4-dimethylhexyl, heptyl, octyl, 2-ethyl-octyl, nonyl, decyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl - and octadecyl groups, alkoxy groups such as methoxy, ethoxy, propoxy, isopropoxy, n-butoxy and n-hexoxy groups, alkyl mercapto groups such as methyl, ethyl, propyl, isopropyl, η-butyl , sec-butyl and tert-Butylmercaptogruppe and optionally substituted phenyl such as chlorophenyl, bromophenyl, tolyl, ethylphenyl methoxyphenyl ₉ and preferably the phenyl group. Examples of substituted phenothiazines include 3,7-dimethyl, 2,8-dimethyl, 3,7-diethyl, 3,7-diisopropyl, 3-tert-butyl, 3-butyl, 3,7- Dibutyl, 3,7-dioctyl, 2,8-dioctyl, 3-methoxy, 3,7-dimethoxy, 2,8-diethoxy, 3,7-dibutoxy, 3,7-dioctoxy, 3 -Methylmercapto-, 2-chloro-, 4-chloro-, 2-bromo-, 4-bromo- and 7-phenylphenothiazine into consideration, whereby 2-chloro- and 3,7-dimethylphenothiazine are preferably used.

Optionally substituted alkylene oxides are used as alkylating agents with 2 to 4 carbon atoms in the alkylene radical, such as 1,2-butylene oxide, Glycidol and preferably ethylene oxide and 1,2-propylene oxide or mixtures from at least two of the alkylene oxides mentioned or of-chloroalkanols with 2 to 12, preferably 2 to 6 carbon atoms, such as 2-chloroethanol, 3-chloropropanol, 4-chlorobutanol, 5-chloropentanol or 6-chlorohexanol into consideration.

BASF Aktiengesellschaft - / - O.Z.

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The alkylation of the optionally substituted phenothiazines with alkylene oxides is carried out at temperatures from 60 to 180 ^e C, preferably 90 to 130 * C at atmospheric pressure or under a pressure of 1 to 10 bar, preferably 2 to 7 bar in the presence of organic solvents inert such as

Benzene, toluene, xylene, cyclohexane and preferably N-methyl-2-pyrrolidone and basic catalysts such as alkali amides, e.g. sodium amide, alkali hydroxides, e.g. sodium or, preferably Potassium hydroxide and alkali alkoxides with 1 to 4 carbon atoms in the alkyl radical, for example potassium ethylate, potassium propylate, potassium isopropylate, Sodium butoxide and preferably sodium methylate and ethylate carried out. The catalysts are used in amounts of 0.01 to 1.1 moles, preferably 0.01 to 0.1 moles per mole of optionally substituted phenothiazine Used and the solvent is appropriately sized so that the reaction mixture has a solids content of 10 to 60 wt.%, Preferably from 30 to 50% by weight, based on the total weight of the reaction mixture. Per mole of optionally substituted phenothiazine 1 to 20 moles, preferably 2 to 5 moles, of alkylene oxide are used. The alkylene oxides are optionally diluted with an inert gas such as nitrogen, incorporated into the reaction mixture to the extent that they react, for example in 0.5 to 2 hours. After the alkoxylation is complete, the alkoxylated, optionally substituted phenothiazines per se known methods isolated from the reaction mixture. For this purpose, for example the basic catalysts bound to ion exchangers, with Inorganic acids or acidic salts are neutralized and then filtered off and any alkylene oxides still present and solvents are distilled off under reduced pressure.

For alkylation with uZ-chloroalkanols, the substituted or unsubstituted Phenothiazines and oJ-chloroalkanols in a molar ratio of 1: 0.8 to 2, preferably 1: 1. to 1.2 in the presence of the above-mentioned inert organic solvents and basic catalysts or preferably in dimethylformamide at temperatures of 50 to 200 ° C, preferably 100 up to 153 ° C, brought to reaction. The N - «^ - Hydroxyalkyl-phenothiazines obtained can be extracted with ether after the solvent has been separated off and, after the ether solution has been dried, the solvent is separated off to be isolated.

The phenothiazine derivatives of the formulas (II) and / or in particular (I) can be found Use as stabilizers, preferably against UV radiation and thermal degradation, for products manufactured by the polyisocyanate polyaddition process Plastics, preferably for compact or cellular polyurethane-polyurea elastomers. The products are used in quantities of

BASF Aktiengesellschaft - <ϊ - OZ 0050/37230

0.05 to 20% by weight, preferably 0.5 to 8% by weight, based on the plastic weight inserted.

Phenothiazine derivatives of the formulas (I) and / or (II) which ^{are liquid at 20 °} C. and in particular those of the formula (I) in which R * and R ^ are hydrogen and R are hydrogen have proven particularly useful and are therefore preferably used , a methyl and / or methylol radical and η is an integer from 2 to 5.

The production of plastics using the polyisocyanate polyaddition process, the phenothiazine derivatives according to the invention of the formulas (I) and / or (II) in an amount of 0.05 to 20% by weight, preferably 0.5 to 8% by weight, based on the total weight, is carried out according to known processes, which are, for example, in the monographs Kunststoff-Handbuch, Volume VII, Polyurethane, (Carl Hanser Verlag, Munich, 1966 and 1969), Integral skin foams, by H. ' Piechota and H. Röhr (Carl Hanser Verlag, Munich, Vienna 1975) or High Polymers, Volume XVI, Polyurethanes Part 1 and 2 by J.H. Saunders and K.C. Frisch (Interscience Publishers 1962 and 1964) as well as numerous patents and applications, such as DE-AS 26 22 951 (US 4 218 543), EP-OS 26 915, EP-OS 69 286, DE-OS 32 15 909 and DE-OS 32 15 907 are described.

example 1

Production of 10- (polyethoxy-polypropoxy) -phenothiazine

199 g of a 50% strength by weight sodium amide solution in toluene were suspended in 4000 ml of toluene under a nitrogen atmosphere and mixed with 1700 g of phenothiazine. The mixture was heated to 115 ° C. in a pressure vessel with a reaction volume of 10 liters, the pressure in the reaction vessel rising to 3.5 bar due to the ammonia released. After the pressure vessel was released, a pressure of 2 bar was set in it with nitrogen. In the course of 7 hours C was alkoxylated with a mixture of 988 g propylene oxide and 187 g ethylene oxide at 115 ^e. After no more alkylene oxide had been taken up, the reaction mixture was allowed to relax and degassed under reduced pressure. The reaction mixture was then treated with 15% by weight of an ion exchanger ('' Ambosol from Societe Nobel Bozel, Puteau (F)) and 1% by weight of water at 100 ° C. for 2 hours with stirring, the ion exchanger was filtered off and the toluene was added reduced pressure (0.05 bar) distilled off.

An N-alkoxylated phenothiazine was obtained, which in statistical distribution 2 Oxpropylen- and 0.5 Oxethylene units contained bound. The dark brown viscous product had an OH number of 158 and a

BASF Aktiengesellschaft - 6 -

O. Z.

0050 / 27.2.30 O k 2 6 J 6 7

Viscosity of 120 mPas at 75 ° C. The ^ -SMR spectrum showed the absorption of the aromatic protons at <T * = 6.7-7.2 ppm, that of the methylene protons at cT >> 3.0-4.1 ppm and that of the methyl protons at (F = 0 , 9-1.3 ppm in the ratio 8: 14: 6.
05

Example 2

The procedure was analogous to that of Example 1, but the polyoxalkylation was used a mixture of 380 g ethylene oxide, 2000 g propylene oxide and 630 grams of glycidol.

This gave 4500 g of a N-alkoxylated phenothiazines having an OH number of 195 and a viscosity of 150 mPas at 75 ^e C.

15 Example 3

The procedure was analogous to that of Example 1, but the polyoxyalkylation was used a mixture of 612 g of butylene oxide and 374 g of ethylene oxide.

2550 g of an N-alkoxylated phenothiazine with an OH number were obtained of 171 and a viscosity of 160 mPas at 75 ° C.

Example 4

40 g (0.2 mol) of phenothiazine and 28 g (0.25 mol) of potassium tert-butoxide were dissolved in 150 ml of dimethylformamide and refluxed in a nitrogen atmosphere in 5 minutes. 100 g of solvent were then distilled off, 52.4 g (0.25 mol) of 1-trimethylsilyloxy-6-chlorohexanol dissolved in 50 g of dimethylformamide were added and the reaction mixture was ^{heated to 140 °} C. for 5 hours. For work-up, the dimethylformamide was distilled off at 30 mbar, the residue was taken up in diethyl ether, the solution was washed with water, the diethyl ether was distilled off and the residue was refluxed with 200 g of methanol and 5 ml of 2N hydrochloric acid for 30 minutes. The solution was concentrated by distilling off 150 g of methanol, the unreacted phenothiazine which precipitated was filtered off and the solvent was completely distilled off. A liquid residue was obtained which, according to high pressure liquid chromatography, consisted of 85% by weight of 6- (u / -phenothiazinyl) -l-hexanol.

The * H-NMR spectrum showed the absorption of the aromatic protons at J ^ = 6.2-7.7 ppm, that of the methylene protons at d * = 3.2-4.1 ppm and 0.9-2.2 ppm and that of the 0H protons at -cT = 2.6-2.9 ppm in the intensity ratio

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ratio 8: 4: 8: 1. All signals are multiplets, Coupling constants could not be determined.

Production of a compact polyurethane-polyurea molded body 05

Comparative example

A component:

Mix of

67.9 parts by weight of a polyoxypropylene-polyoxyethylene triol with a hydroxyl number of 26, prepared by polyaddition of 1,2-propylene oxide to trimethylolpropane as a starter molecule and subsequent polyaddition of ethylene oxide, 21.0 parts by weight of 2,4-dimethyl -6-tert-butyl-phenylenediamine-l, 3, 4.0 parts by weight of pure phenothiazine,
6.0 parts by weight of black paste,
1.0 part by weight of 1,4-diazabicyclo- (2,2,2) -octane in dipropylene glycol (33% by weight solution) and
0.1 part by weight of dibutyltin dilaurate.

B component:

methane-modified 4,4'-diphenyl line than diisocyanate with an NCO content of 23% by weight, produced by reacting 4,4'-diphenylmethane diisocyanate and dipropylene glycol

100 parts by weight of the Α component and 52.8 parts by weight of the B component - corresponding to an isocyanate index of 1.05 - were heated to 50 ° C and, according to the heat injection molding process, on a high-pressure metering system of the Puromat type ' ⁵ "'30 from Elastogran Maschinenbau GmbH in an aluminum mold with internal dimensions of 4 × 400 × 200 mm, temperature-controlled at 50 ° C., to form mold plates Exposure to irrigation cycle of 17: 3 1000 hours exposed.

The exposed shaped platelets showed, besides a slight matting, no embrittlement, chalking, cracks or similar phenomena on the surface. Elin dismantling of the forra plate surface did not take place. However, exposed and unexposed molded platelets showed bluing of the black ones after storage for a few weeks at room temperature Surface, comparable to a drop of oil on the surface of water.

BASF Aktiengesellschaft -W- _O .Z. 0050/37230

Example 5

Α component: mixture of

64.9 parts by weight of a polyoxypropylene-polyoxyethylene triol with a hydroxyl number of 26 made by the polyaddition of 1,2-propylene oxide on trimethylolpropane as a starter molecule and subsequent oxethylation,

21.0 parts by weight of dimethyl-6-tert-butyl-phenylenediamine-1,3 7.0 parts by weight of alkoxylated phenothiazine, prepared according to the example 1.6 parts by weight of black paste, 1.0 part by weight of 1,4-diazabicyclo- (2,2,2) octane (33% by weight solution

in propylene glycol) and 0.1 part by weight of dibutyltin dilaurate. 15 B component: analogous to the comparative example

The manufacture of the mold plates and their exposure and weathering was carried out analogously to the information in the comparative example.

The shaped platelets did not show any degradation on the surface. Even after After several weeks of storage analogous to the information in the comparative example, no migration of the alkoxylated phenothiazine was associated with the molded platelets observed with a superficial, color change. 25th

Claims (10)

BASF Aktiengesellschaft O. Z. 0050/37230 patent claims 1. Use of phenothiazine derivatives of the formulas C. > - (CH "CHR ³ -O)" - H and or in which R * and R ^ are the same or different and are hydrogen, halogen, a An alkyl group with 1 to 18 carbon atoms, an alkoxy group with 1 to 18 carbon atoms, an alkyl mercapto group having 1 to 18 carbon atoms or an optionally substituted phenyl radical, R ^ hydrogen, a methyl, ethyl and / or methylol radical, η an integer from 1 to 20 and
m is an integer from 3 to 12, as stabilizers for after the polyisocyanate polyaddition process manufactured plastics. 2. Use of ^{phenothiazine derivatives of the formulas (I) and / or (II), which are liquid at 20 °} C., in which R ^, R, R ^, η and m have the meaning given above, as stabilizers for the polyisocyanate polyaddition process manufactured plastics. 3. Use of phenothiazine derivatives of the formulas (I) and / or (II), in which R *, R ^, R ^, _n and m have the meaning given above, as Stabilizers against UV radiation and thermal degradation for after Plastics produced using the polyisocyanate polyaddition process. 40 156/84 M / Kl 17.07.84 BASF Aktiengesellschaft - 2 - OZ 0050/37230 4. Use of phenothiazine derivatives of the formulas (I) and / or (II), in which R ¹ , R ² , R, η and m have the meaning given above, as stabilizers for compact or cellular polyurethane-polyurea elastomers. 5. Use of phenothiazine derivatives of the formulas (I) and / or (II), in which R> R> R> η and m have the meaning given above, in an amount of 0.05 to 20 wt.%, Based on the total weight, as Stabilizers for products made by the polyisocyanate polyaddition process Plastics. 6. Use of phenothiazine derivatives of the formula (I) in which R * and R ^{2 are} hydrogen, R ^ are hydrogen, a methyl and / or methylol radical and η is an integer from 2 to 5 as stabilizers for products prepared by the polyisocyanate polyaddition process Plastics. 7. Use of phenothiazine derivatives of the formula (I) which are liquid at 20 ° C., in which R ¹ and R ^{2 are} hydrogen, R- * is hydrogen, a methyl and / or methylol radical and η is an integer from 2 to 5 in an amount from 0.5 to 20% by weight, based on the total weight, as stabilizers against UV radiation and thermal degradation for plastics produced by the polyisocyanate polyaddition process, preferably for compact or cellular polyurethane-polyurea elastomers. 8. Plastics produced by the polyisocyanate polyaddition process, containing phenothiazine derivatives of the formulas (I) and / or (II), in which R »R > Rj η and m have the meaning given above. 9. New phenothiazine derivatives of the formulas (I) and (II), in which R ¹ , R ² , r3, η and m have the meaning given above, with the exception of lO- (ß-hydroxyethyl) -, lO- (ß-hydroxy- propyl) - and 10- (• jf -'-hydroxy-propyl) -phenothiazine. 10. A process for the preparation of phenothiazine derivatives of the formula (I) in which R ^, R, R have the meaning given above and η is 2 to 20, characterized in that optionally substituted phenothiazines in the presence of basic catalysts with 2 to 20 moles of alkylene oxide from the group consisting of ethylene oxide, 1,2-propylene oxide, 1,2-butylene oxide and / or glycidol are oxyalkylated.