DE2065975A1 - Alpha,alpha-bis-(o-hydroxyphenol) diisoprop - ylbenzene - Google Patents

Abstract

Alpha, alpha'-bis-(O-hydroxyphenol) di isopropyl benzene. Stabilization of polyurethanes (I) against light, heat and air, by incorporating 0.01-10 wt.% wrt (I) of a para-bisphenol of formula (II): (where R is 1-18C alkyl, 5-6C cycloalkyl or 7-9C aralkyl and R=methyl, t-butyl, cyclopentyl or cyclohexyl). (II) may be added with the reactants of (I) or to (I) itself. An (O-hydroxyphenyl) 2-benzotriazole at 1-10 to 10:1 wrt (II) may also be included. (I) is an elastomer prepd. by reacting a polyhydroxy cpd. of m. wt. 500-5,000 with excess diisocyanate. The bisphenol is superior as a stabilizer to known cpds. for polyurethane elastomers esp. for threads and films. The additive is resistant to washing and is colourless.

Description

The invention relates to a method for stabilizing segmented polyurethane elastomers against degradation and Discoloration in warmth and atmospherics.

Polyurethanes, which are made from high molecular weight polyhydroxy compounds, polyisocyanates and chain lengthening agents in foams , elastomers, coatings, foils or slastomer threads are widely used - depending on their structural components - against the effects of light, but sometimes also in air at higher temperatures, unstable and their strength values are reduced as a result, and in many cases there is also strong discoloration of the polyurethanes.

Many efforts have already been made to achieve protection against discoloration and degradation by adding known antioxidants, for example those based on phenols , but this stabilization is generally not sufficient.

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For example, phenols such as 4 _f 4'-alkylidene-bia- (6-tert-butyl) -n-cresol, 2,6-di-tert-butyl-4-methyl-phenol or 4,4'-methylene-bis- (2,6- ditertiary butylphenol) as stabilizers, but these show either a disturbing initial discoloration or a failure of the protection against discoloration when exposed to light or atmospheric agents. Furthermore, polyphenols, such as, for example, 1, JS-trimethyl- ^^. Ö-tris- (3i5-di-tert-butyl-4-hydroxybenzyl) -benzene, have been proposed as all stabilizers (DT-AS 1 243 866). A number of phenolic compounds were also mentioned which, together with hydroxybenzophenones, are said to be suitable for stabilizing polyurethanes (DT-AS 1 106 490). However, the effect of these phenolic stabilizers is not sufficient. They are not washable and have a color of their own which, for example, is unsustainable for white elastomer threads.

A new class of phenolic stabilizers has now been found which, due to their typical structure, enables highly effective stabilization of polyurethanes, whereby these. Stabilizers colorless, do not cause discoloration in polyurethanes and a significantly improved Protection against discoloration and degradation when exposed to visible and / or UV light and / or atmospheric agents (such as oxygen, nitrogen oxide or combustion exhaust gases) also provide the substances in the polyurethane elastomers are readily soluble and do not crystallize out on the surface.

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The invention relates to a method for stabilizing segmented polyurethane elastomers against degradation and discoloration when exposed to light, heat and atmospheres, characterized in that

a) bisphenols of the general formula

in which R is a straight-chain or branched C ₁ -C _{1 Q-alkyl radical, a C 5} -C ₆ -cycloalkyl radical which is unsubstituted or substituted by lower alkyl radicals or a C 1 -C 6 aralkyl radical,

b) a 2- (2'-hydroxyphenyl) benzotriazole of the general formula

^R 1

χ oi

in which X is hydrogen, alkyl or halogen, Y is hydrogen, an O ₁ -O ₁₂ -AIlCy Ire et or an Allcylenreit nit heteroatoms, R _{1 is} hydrogen or a C ₁ -C ₁₂ -Alley Ire et, in amounts of 0.05 - 5.0 percent by weight,

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pulled on the polyurethane elastomers, the weight ratio from a to b is 10: 1 to 1:10, the polyurethane elastomers or the polyurethane elastomers forming starting compounds are added.

Examples of radicals R for the compound of the formula (I) are called:

Methyl, ethyl, n-propyl, iaopropyl, η-butyl, aek. -Butyl-, tert-butyl, amyl, isoamyl, hexyl, isohexyl, isooctyl, Isononyl radicals; Cyclopentyl-, cyclohexyl-, + -Methylcyclolieapyl-, od-methylcyclohexyl create; Benzyl-, cc-methylbenzyl-, α, 0L-Dinethylbenzylreete.

The bisphenols of the general formula are preferred

in which R is a methyl, t-butyl, cyclopentyl or cyclo Λ

hexyl group means to use.

The following stabilizers are particularly preferably used .

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CH ₃ 35 CH

OH,

OH

II

CH,

^OH CH, _ CH ₃ ^OH

y CH ₃ ^{Xe /} CH,

OH,

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The invention of, d. l-bis- (2-hydroxyphenyl) -1,4-diisopropylbenzenes, which are also referred to below as bis-phenols for short, are new compounds and can be obtained by reacting <C, JL '-dihydroxy-1,4- Prepare diisopropylbenzene with ortho-substituted 4-methylphenols with elimination of water in the presence of acidic dehydration catalysts, for example according to the following reaction equation ι

OH,

HO-C-CH,

CH,

I ³

-C-OH

CH,

CH ₃ OH

H ₂ O

in which formula R has the meaning given for formula I already.

The significant improvement that recoverable by using the new Bie-phenol · together with the benzotriazoles bar, in comparative tests against a commercially available mononuclear phenol, 2,6-di-tert - butyl-p-cresol, a dinuclear phenol, de «methylene bi- (2-hydroxy-3-tert-butyl-5-methylphenol, and a trinuclear phenol, the 1,3,5-trimethyl-2,4,6-tri- (3,5-di- tert-buty1-4-hydroxybenzyl) benzene (X) is shown in 2 more

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Examples in which an unsubstituted in the ortho positions Bis-phenol (VI) and also a bis-phenol with OH groups in the p-division (VII) (as described in the BE-PS 604 516) were used, the strict dependence on the effect and constitution of the Bis-phenols shown.

OH CH

HO-

3H-CH, ⁵ VII ³

It shows, among other things, that similarly constructed phenols, often reacted as stabilizers, which, however, instead of the -C (CHj) ₂ grouping only have a -CHg group between the benzene nuclei, aB bis- or trisphenols, such as

* VIII '

/ CH3 CH

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or

OH I

^ pC (CHj) ₃ CH,

compared to the stabilizers according to the invention on exposure show strong self-discoloration (yellow) in UV light and are therefore unsuitable for stabilizing colorless polyurethanes. In addition, the bis-phenols according to the invention show a better one Stabilization against degradation as, for example, the known phenolic stabilizer 1,3,5-trimethyl-2,4,6-trie (4-hydro3cy-3,5-di-tert.-butylbenzyl) benzene (according to DT-AS 1 243 866 ). At relatively low Modification of the structure of the phenols according to the invention, e.g. If the alkyl radicals are shifted, the stabilization effects are significantly lower or, in some cases, also yellow discolouration observed (see comparison experiments).

The stabilization of the special phenolic compounds according to the invention, which is so significantly effective for polyurethane elastomers, was surprising and could not be foreseen.

Surprisingly, the effectiveness of the phenols is not ttrt for the presence of tints. Alkyl radical in o-position limited to the hydroxyl group and there are Ytr bonds as well as secondary or primary alkyl radicals also work well.

As 2- (2'-Hydroxyphenyl) -benztriaeole are solhe the following Formula used:

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(II)

Here, X denotes hydrogen, alkyl, halogen, Y _{denotes hydrogen, a C 1} -C ₁₂ -AIlCyI-ReSt or an alkylene radical with heteroatoms, preferably a tert. Alkylreat, for example tert.-Butyl, tert-amyl, tert-dodecyl, R ₁ is hydrogen or a C ₁ -C ₁ 2 "alkyl, eg methyl, ethyl, iso-propyl, tert-butyl, tert-butyl Amyl, tert-octyl, tert-dodecyl.

The mixture is used in a weight ratio of compounds a) and b) of 1:10 to 10: 1, as a result of which the polyurethane elastomers experience a synergistically effective stabilization against discoloration and degradation when exposed to light, heat and atmospheric agents.

The use of 2- (2'-hydroxyphenyl) benzotriazoles as stabilizing additives in polymers is known per se, but it is completely inadequate as the sole stabilizer. Also a combination of 2- (2'-hydroxyphenyl) -benztriazoles and 1,3,5-trieethyl-2,4,6-tri- (3,5-di-tert-butyl-4-hydroxybenbyl) -benzol or 1,2,4,5 -Tetraeethrl-3 ₁ 6-bis (3,5-ditertbutyl-4-hydroxy-benzyl) benzene is described for the stabilization of segmented polyurethanes in NL-AS 6,509,745. This susatce had a certain, but not sufficient, protective effect and there remains a need for a highly effective, permanent stabilization of llastic, spellular Ilaeto filaments.

Benztriasols are preferably used as compound (b)

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the following formula in mission / ^R 1 Λ χ · " y

wherein

X hydrogen or chlorine Y hydrogen or a Cj-C ^

preferably tert-alkyl, for example tert-butyl, tert-amyl _f or an -N-methylene-phthalimido radical and. 0? Hydrogen or a Cj-Cjg-alkylreet, e.g.

Methyl, ethyl, isopropyl, tert-butyl, tert-anyl represent.

As a light stabilizer based on 2- (2'-hydroxyphenyl) benztria «ol the following connections are to be mentioned, for example:

2- (2'-Hydroxy-5'-methyl-phenyl) -benztriazole

2- (2 ·-hydroxy-5'-methyl-phenyl) -5-chloro-ben "triazole 2- (2'-hydroxy-3 ¹ -tert-butyl-5-methyl-phenyl) benzotriazole 2- ( 2 ^f -hydroxy-3'-tert-butyl-5-methyl-phenyl) -5-chloro-benz-

triazole

2- (2'-Hydroxy-3'-methyl-5-tert-butyl-phenyl) -benztrlazole 2- (2-hydroxy-3 ¹ -methyl-5-tert-butyl-phenyl) -5-chloro -benz-

triazole

2- (2'-hydroxy-3 ', 5'-dimethyl-phenyl) r -benetriazole

2- (2'-Hydroxy-3 ', 5'-dimethyl-phenyl) -5-chloro-benzotriazole 2- (2-hydroxy-3', 5'-di-tert-butyl-phenyl) -benstriazole 2 - (2'-Hydroxy-3 ', 5'-di-tert-butyl-phenyl) -5-chloro-b # n "tria" ol 2- (2 · -hydroxy-3', 5'-di- tert-amyl-phenyl) -benztriazole 2- (2'-hydroxy-3 ¹ , S'-di-tert-amyl-phenylJ-S-chloro- bexiatriasol 2- (2'-hydroxy-3 ¹ , 5 ' -di-ttrt.-octyl-phtnyD-btnitriaiol 2- (2'-hydroxy-3 ' % 5'-di-tert.-octyl-pheuyl) -5-chloro-bea2trla * ol 2- (2'-hydroxy- 3 ¹ -N-methylene-phthalimido) -ben8triazole

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Further suitable hydroxyphenylbenzotriazoles are, for example, in DT-AS's 1 213 408, 1 213 409, 1 213 410, and U.S. Patent 3,213,058, respectively. Known polyurethane stabilizers (see e.g. DT-AS 1 157 386) can can also be used.

The elastic polyurethanes to be stabilized, which are optionally present in foamed form, can be produced by processes known per se and from the known starting materials. They are polyurethanes in general by reacting higher molecular weight polyhydroxyl compounds (for example polyester or polyether with a molecular weight of about 500 to 5,000, melt products preferably below 60 ⁰ C) and aliphatic, araliphatic or aromatic polyisocyanates (preferably aromatic Siisοcyanate η such as tolylene diisocyanate or siphenyl methane-4 , 4'-diisocyanate) and so-called lette extenders, ie low molecular weight compounds (molar weight, for example 18 to 400) with two or more groups that are reactive towards ieocyanate (for example water, low molecular weight sols, diamines, sihydrazides or similar compounds, such as amino alcohols, aminohydrazides , Hydroxyhydrazide, Amino-semicarbazide, Semicarbazidhydrazide, Senicarbazidocarbazine ester or corresponding Oemisohe of these letten-lengthening agents in one or more stage processes in melt or in solvents according to a variety of known and modifiable processes produced

Examples of starting materials are: polyesters made from adipic acid and sialcohols of 2 to about 10 carbon atoms, preferably soles with more than 5 carbon atoms, the Bial alcohols can also be used in a mixture to lower the SehmelBpunkt of the polyesters; Polyester from caprolaeton and sialcohols, furthermore polyalkylenatherdiols, especially polytetramethylene ether diols, polytrimethtlenatfa.tr-

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diols, polypropylene glycol or corresponding copolyethers. As Diiaocyanate preferably aromatic diisocyanates such as ^{Siphenylmethan-4f4->} _t -dii0Ocyanat be tolylene diisocyanate, araliphatic, such as m-xylylene diisocyanate or aliphatic "diisocyanates such as hexamethylene diisocyanate and dicyclohexylmethane-4,4 ^l -dii8ocyanat used. These starting materials are reacted - optionally with dialcohols additionally used - to give NCO pre-adducts, which preferably have the structures given in Belgian patent 734 194. As chain extenders - optionally as a mixture or in stepwise conversion - water and / or di- or tri-alcohols such as butanediol and p-xylylene glycols, trimethylolpropane, amino alcohols such as ethanolamine, diamines such as diphenylmethane-4,4 ^l- diamine, 3 »3'-diehlor diphenylmethane-4,4-diamine ^f, but preferably aliphatic diamines such as Äthylendiamln, 1,2-propylenediamine, Isophorondiaain, aeta-xylylenediamine and hydrazine or dihydrazides such as carbodihydrazide, Oxaleäure-dihydraeid, ölutarsäuredihydrazid, Pimelinsäuredihydrazid, terephthalic acid dihydrazide, or Seaicarbasidhydrazide as (h -Semicarbaaid-alanylhydraeid, optionally as mixtures of the chain release agents for use.

Preference is given to stabilizing polyurethanes which, apart from urethane groups, are also formed by the addition of isocyanate groups with compounds containing water and / or KHg groups (e.g. diaains, dihydrazides, carbodihydrazides, semicarbaid hydrazides or hydrazine) -MH-CO- HH groups and an essentially linear, segmented molecular structure, are soluble in highly polar solvents such as dimethylformamide or dimethylacetamide before their formality, especially whose characteristic segments can be characterized by the following shape:

-j- T.NH.00.ITH.I.ITH.00.IH 4-

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this segment may have arisen from the conversion of an NCO pre-adduct OCN.Y.NCO with a chain extender HgN.X.NH ₂ .

The remainder -Y- of the NCO pre-adduct can be built up as follows, for example:

-R.NH.CO.0.D.O.CO.NH.R-

or have other, customary compositions (cf. Belgian patent 734 194).

Here, R denotes a divalent aliphatic araliphatic Beher or aromatic radical (a diisocyanate), D the radical of a higher molecular weight polyhydroxyl compound with a molecular weight of 500 to 5,000 and melting points below 60 ^° C. without their terminal hydroxyl groups (e.g. radical of a polyalkylene ether, polyester, polyacetal, poly -N-alkyl urethane). I iet the residue of a divalent chain extender with terminal NHg groups without the terminal NHg groups, for example an aliphatic, araliphatic, aromatic or heterocyclic radical, an -HN-CO-alkylene-CO-NH-Reet, an -NH-CO-NH - (CH ₂ ) 2-CO-HH-Reet or a bond between two N atoms. The synthesis of such polyurethane (ureas) is described in detail, for example, in DT-AS 1,270,276 and in BE-PS 734,194. Polyurethane foams can, for example, with the addition of stabilizers to the starting components (see PolyMther) according to known processes and formulations (B.Plastic Handbook, Volume. TCI, Polyurethane, Carl Hanser Verlag Munich, 1966, pages 440 to 457 , 504 to 531).

The stabilizers may _{polyurethanes:} in any, the process engineering aspects adapted Veiee incorporated

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will. The simplest metering results when the optionally dissolved stabilizers are added to solutions of the polyurethanes, for example to those used for spinning and coating processes. Solutions in highly polar solvents, for example dimethylformamide or dimethylsulfoxide, are preferred for coagulation purposes. With the help of suitable mixing devices such as kneaders or rollers, however, the stabilizers can also be incorporated into the melts or plasticized polyurethane sheets. The stabilizers can optionally also have elastomer threads applied to the surface together with the preparation.

Another possibility is to add the stabilizers to the starting materials for polyurethane production and to carry out the polyurethane synthesis only with these. The bis-phenol compounds are soluble in the higher molecular weight polyhydroxyl compounds (eg polyesters or polyethers). With such stabilizer-containing polyesters or polyethers, corresponding polyurethane syntheses, for example the production of foams or elastomers , can then be carried out. The stabilizers can also be added to the diisocyanates or HCO pre-adducts formed from higher molecular weight polyhydroxy compounds and (excess molar amounts) diisocyanates before the polyurethane is formed, for example by spinning into aqueous diamine solutions. By using the stabilizers in the unsetsung of NCO pre-adducts old chain extension agents such as diamines, hydrazine, hydrazides or similar chain extenders in highly polar solvents such as dimethylformamide or Diaethylaoetaaid, you can prevent the coloration of the polyurethanes during their synthesis . The amount of stabilizers added is 0.01 to 10 percent by weight, preferably 0.2 to 3.0 percent by weight.

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By adding the claimed stabilizers to polyurethanes, which contain reaction components with tertiary, aliphatic substituted amino groups in amounts of 0.02 to 1 mol, preferably 0.05 to 0.3 mol per kilogram of elastomer substance, a further increase in the light weight effect is observed. As such, the reaction components glycols, diamines, or polyester or Dihydraaide PoIyäther having tertiary amino groups are, for example, be mentioned, Sb, N, N-bending (.beta.-hydroxypropyl) methylamine, N, N '-bis- (fl-hydroxyethyl) piperazine, N, N'-dimethyl-, N, N'-bis - (^ f-aminopropyl) -äthylen- -diaiain, Ν, Ν'-bis - ^ - aminopropylj-piperazine or tert. Amino group-containing polyethers or tert. Amino group-containing polyesters, which using tert. Amino group-containing dialcohols are prepared.

The first H ¹ PTIg of the bisphenols of the general formula I according to the invention.

The synthesis of the bis-phenols can be carried out by reacting cL , ot "- dihydroxy-1,4-diieopropylbenzene with ortho-substituted 4-methylphenols with elimination of vaaser in the presence of acidic dehydration catalysts, such as p-toluene sulfone Mure, phosphoric acid, sulfuric acid, hydrochloric acid or strong acidic ion exchangers.

The water formed during the condensation can optionally be removed by aieotropic distillation *. As a solvent i.B. Bemol, Cyolohexane, Waaohbensin, Toluene, xylene and chlorinated hydrocarbons such as chloroform, carbon tetrachloride and tetraclorethylene are used will.

A further process for the preparation of the bis-phenols according to the invention consists in CL, ct'-dihydroxy-i, 4-diieopropyl-

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benzene with 2 molecules of p-cresol under water removal to condense the above-mentioned process and then the free orthodontics with suitable olefins or To alkylate, cycloalkylate or aralkylate carbinols.

Such processes are known as such and are also not part of the present invention.

Rather, the following examples are intended to provide a more detailed explanation of the preparation of the bis-phenols according to the invention as well as the two compounds VI and VII used for comparative experiments.

oL, oc'-BiB- (2-hydroxy-3.5-dimethylphenyl) -1 .4-dlisoOropylbenzene (compound II on page 4) :

220 g (1.8 mol) of 2,4-dimethylphenol, 97 g (0.5 mol) of οι, OU * -dihydroxy-1, 4-diisopropylbenzene and 500 ml of xylene were with the addition of 5 g of p-toluenesulfonic acid for 1 hour on Boiled water separator, separating 18 ml of water. After cooling the mixture with 500 ml of petroleum ether was added, cooled to 5 ⁰ C and filtered with suction the precipitated colorless crystal ·. These have a Schmelepunkt of 178 - 179 ⁰ C.

^C 28 ^H 34 ° 2 Molecular weight 83.58 H: : 402, 0: 7, 96 ber .: C: 83.9 H: 8.46 Oi 7, 9 found: 0: droxv — 3 — t he 1 c ** Iy 8.7 fttf SSL α. οι'-Bia- (Link III 4): is oT> red) vlbentol on page

164 g (1 mol) of 2-tert.-butyl-p-kr "" ol, 49 f (0.25 hol) Ot, Ot ¹ -dihydroxy-1,4-diisopropylbene sol and 2.5 g of p-toluenesulfoic acid in 400 ml of white spirit were boiled for 1 hour on a water separator, 9 ml of water separating out. For ffeutrali-

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2 g of ammonia were introduced into the catalyst. The mixture was filtered and distilled to 10O ⁰ G in vacuo. A colorless powder precipitated out on addition of methanol. This was suctioned off and dried. Mp 105 C.

^C 34 ^H 46 ° 2 Molecular weight 486 calc .: C: 83.95 H: 9.47 0: 6.58 found: C: 83.9 H: 9.4 0: 6.0

_r%% oL '-bis - * (2 ~ hydroxy - 3-cyclopent.yl-5-methyl-phenyl) -1.4-diisopropylbenzene (Compound IV on page 4):

352 g (2 mol) of 2-cyclopentyl-p-cresol, 97 g (0.5 mol) of egg, oc'-dihydroxy-1,4-diisopropylbenzene and 5 g of p-toluenesulfonic acid in 500 ml of mineral spirits were boiled on a water separator for 2 hours , 18 ml of water separating out. Introduced into the solution WUR to 2 g ammonia, filtered and treated with 500 ml of methanol. The precipitated crystals were recrystallized from toluene for further purification. Colorless crystals. Pp 220 ⁰ C.

^C 30 ^H 46 ° 2 Molecular weight 510 0: 6th , 28 ber . : C: 84.7 H: 9 , 02 0: 6th , 3 found: C: 83.9 H: 9 ,1

d. oil '-Bis- ^ -hydroxy ^ -cyclohexyl-S-ethyl- phenyl ) -1.4- diisopropylbenzene (compound V on page 4):

380 e (2 mol) of 2-cyclohexyl-p-kreeol, 97 ° C. (0.5 mol) cW.oC 'hydroacy-1,4-diisopropylbeneol and 5 g of p-toluenesulfonic acid in 600 ml of white spirit were boiled on a water separator for 1 hour , wob ·! Separate 18 ml of water. At 50 ^° C., 2 g of ammonia were introduced. After filtration, 500 ml of methanol were added to the solution, colorless crystals separating out. Pp. 204 ⁰ C.

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^C 33 ^H 50 ° 2 Molecular weight 538 calc .: C: 84.76 H: 9.29 0: 5.95 found: C: 84.1 H: 9.3 O: 6.2

q, οι- '-Bis-fZ-hydroxy-S-methyl-phenyD-i .4-dliBopropylbenzene (compound VI on page 6):

216 g (2 mol) of p-cresol, 97 g (0.5 mol) of Ct, oL ¹ -dihydroxy-1,4-diisopropylbenzene, 5 g of p-toluenesulfonic acid and 500 ml of mineral spirits were boiled on a waaaerabscheider for 1 hour, whereby .eich Separate 18 ml of water. The product that was crystallized out was ^{filtered off with suction at 0} ° C. and recrystallized from benzene. Colorless crystals. Pp. 183 ⁰ C

^C 26 ^H 30 ° 2 molecular weight 374

calc .: C: 83.42 H: 8.02 0: 8.56 found: C: 83.7 H: 8.0 0: 8.9

oil, pi '-BiB- (4-hydroxy-3.5-dimethyl-phenyl) -1.4-diisopropylbene sol (compound VII on page 6):

122 g (1 mol) of 2-hydroxy-1,3-dimethylbenzene, 49 g (0.25 mol) of α, oc'-dihydroxy-1,4-diisopropylbenzene, 2.5 g of p-toluenesulfonic acid and 300 ml of mineral spirits were added for 1 hour Boiled on the water separator , with 9 ml of water separating out. 1 g of ammonia was passed into the hot solution. After filtering and cooling, 250 μl of petroleum ether were added to the solution, and the precipitated crystal pulp was suctioned off ^{at 0 ° C. and crystallized from toluene.} Colorless crystals. Mp. 160 ⁰ C,

^C 28 ^H 34 ° 2 molecular weight 402

calc .: C: 83.58 -H: 8.46 0: 7.46 found: C: 83.6 H: 8.6 0: 8.2

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example 1

500 parts of a Polytetramethylenätherdiols (molecular weight 1010), 104 parts of N, N-bis (.beta.-hydroxypropyl) -N-methylamine, 1 822 parts of diphenylmethane-4,4'-diisocyanate ^l and 1740 parts of chlorobenzene 68 minutes 60-68 ⁰ C heated and then cooled to room temperature. 6450 parts of this NCO pre-adduct solution (2.05 % NCO based on solids) are converted into a fresh suspension within 10 minutes, prepared by adding 75 parts of solid carbonic acid to a solution of 73.7 parts of ethylenediamine and 4.68 Parts of 1,2-propylenediamine in 13,440 parts of dimethylformamide, added with thorough stirring, a homogeneous, pale yellowish elastomer solution is formed, the addition of 4% by weight (based on solid elastomer substance) titanium dioxide (rutile) is pigmented. The elastomer solution (viscosity 610 poise) is converted into films in the usual manner without any stabilizer being added, these are cut into threads and, as such, irradiated with UV light (fadeometer) (see Table 2). Portions of these elastomer solutions were spun using the customary dry spinning process and the threads were irradiated with or without the addition of stabilizers in a Xenotest exposure device (cf. Table 1). If the weight 2 ^ stabilizer added not only subsequently the finished Elaetomerlösung, but together with the diamines dissolved in dimethylformamide and then with the NCO

When the elastomer solution is produced as an adduct, a colorless elastomer solution is obtained that does not change color when exposed to air. After casting into films and exposure of the threads, a practically identical stabilizing effect against strength degradation was measured under exposure.

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Tabel

Featip; koltaahfall of Elantomer threads after the dry spinning process (single titer approx. 10 dtex-Geaaiittiter approx. 220 dtex) after Xenotest exposure «

For d. exposure fracture
strain J2 hours fracture
strain 145th hours fracture
strain 480 Remarks without stabilizer Tear
sturdiness
g / dtex 506 Tear
sturdiness
g / dtex 372 Tear
sturdiness
g / dtex no longer measurable
yellowish - yellow 525 1 % stabilizer II 0.59
(colorless) 500 0.17
yellowish - 0.40
colorless 512 only after more
than 200 hours
Pale 2 % stabilizer II 0.61
colorloe ^ 510 colorless 0.52
colorless only after approx.
225 hours
yellowish 1.33? 6 stabilizer
+ 0.67 % 2- (2'-Hy-
drexy-3'-t-b »tyl
5 '- "* thyl-ph" nyl) -
benstriasol 0.66
colorloe 510 colorless 510 0.60
colorless 0.66
colorloe 0.63
colorless effective
Mixture.
Only after approx.
300 hours
yellowish

Example 2

The bis-phenols or comparative stabilizers shown in the table are dissolved in the stated amounts in the elastomer solution (according to Example 1 ). After the elastomer solution has been poured and dried to form films, film strips are cut and exposed in the padeometer for the specified time .

it

-P

CM

Φ
H

cH φ

<P

GH

υ w

Λ Φ

S-i

• Η Φ

4 » C

ιΗ ■ Η

+3

J2

4 * 'Φ

a ' φ H bO H W.
P. bO KN CQ _β I I U ρ- ΙΛ CQ H ω O r-i η Φ φ CQ in ω O O 43 α) O ■ τ— O Φ C- • Η ϊ • β 49 Φ 3 VO O ιΗ H Φ #C P P • Η VO H P 4 * VO H Xt Φ ■ Ö β ö H CMP B. Ο03 H H • HP P. C * 43 S bO Xt CO 4 »P C * "F4 ^ a • Η Φ Φ h P. O ^ rH Pi Οι • Η in co u ·. (j O% Η C a μ ^ " «Η OfH a Φ SH B OVD Pq ***** bO a Φ «Cd α) Ο <Η (4th • φ • k bO S bO φ P. Ο «Η <Η Xt ato O bO O 0 τ- ρ « bO bO 13th
4 » β
• Η CQ Xt ^ O «Ι CM r-4 C- O τ- Pt C- O Xt • Η Φ VO CQ Xt * H CM IO H CJN ■ Η r { gj β νο * "- * · ο VO ρ ITN VO P. VO H O ιΗ 4 * H a P. * H P I. • Η · CM CQ P + COM B. VO Vi O ιΗ H W ^
bOO νο cd U O * # ■ Φ Q) * τΙΗ »<Η CO H bO Ο * - 'Vt P. O O ¹ OP a Φ O a approx ^ _- 43 O Φ O CM U O O O S. ν / I Φ ο CM CQ KN ιΗ ο
Λ * , M. VO 5 VO O VO W.
"Ö d CD Γ ■ Η Ot Xt
CMp P. Vl ΙΑ Φ4> VO 9 4 » O <H KN CQ υ IfN ^ £> ϋ tiCM Vl CCM ve Q O j. O 0 _β •H O KN B. O iH ato H '* ~ O Oi B.
• Η P. VO H IfN a H 2 P. 0 Φ • Η M.
CD H • Ö ι »P *H P. as IfN VO a oca U.N. «* · «Μ O O J I. I. ato ill ill Q
• Η Φ Ct) M PM
OtM ιΗ Μ 4 » 4 » • H43 CO U CO U PSt) * B.
+ »S. CON

CNJ CM

Le A 17 887

- 21 -709834/0780

-ο
co
α »

Table 2 (continued)
Fadeoineter - exposure of flint elves or cutting threads.

Stabilizer
Accessories in front of the Belich
tion
RF * Dhg
g / dtex colorless according to Fadeoineter -
22 h
RF i » Dhg
g / dtex Exposure of
44 h
RH % Dhg
g / dtex 66 h
RH % Dhg
g / dtex + 1.33 t Sta
bilizer II
0.66 Jt UV-Ab
sorber x) colorless XX)
colorless xx)
colorless XX)
almost colorless 2 %
stabilizer xx)
colorless xx)
colorless xx)
holds colorless
pale yellowish XX)
pale yellowish III rx)
colorless xx)
colorless xx)
almost colorless
Pale yellowish 2 % stabil
aator IY colorless xx)
colorless xx)
almost colorless
weakly yellowish xx)
pale yellowish 2 i Stabili
aator T Veröltichaveruuche: xxx)
yellow
(ready from 3pm) xxx)
intense yellow xx)
almost colorless
pale yellowish 2 * conn
dung TI xxx)
intense yellow

Footnotes b. Page 22

Table 2 (postage)
Fadeometer - exposure of filmo strips or cut threads .

co e »ι

Stabilizer accessories

before exposure

RH% Dhg g / dtex

according to fadeometer

22 h

RH % Dhg

g / dtex

Tergltichaverauche (continued):

7> * m-Λ. WJ.B

dung TII

colorless

xxx)

yellow

(ready from 3pm)

Exposure of

44 h RP % Dhg

g / dtex

xxx) intensive yellow

% 1.3.5, -

Trimethyl - 2.4,6, -trie (3,5-di-tertiary-butyl-4-hydroxy-benzyl)

(Compound X) -benzene.

1> connection II

colorless.

almost colorless

xxx)

almost colorless

yellowish

Firmness relatively Btark yellow

xxx) yellow

well preserved, intense yellow

66 h

RP i » Dhg

g / dtex

xxx) intense yellow

heavily degraded, intense yellow

yellow-brown

x) 2- (2'-Hydro3ty-3'-tert-butyl-5 ^l -iethyl-phenyl) -5-chlorobenz-triazole. Zx) Strength largely retained, no cracking during stretching. Xxx) When stretched, the fibers show strong cracking and occasionally pre-torn flakes with increasing exposure time.

As the results show, both in terms of maintaining mechanical strength and reducing the Discoloration achieved by the stabilizers according to the invention a very good improvement, which is achieved when using Increase UV absorbers of the 2-hydroxyphenylbenzotriazole type leaves. The use of triphenyl phosphite or triphenyl phosphine does not result in any significant improvement. The compounds VI and VII, which have only slight deviations from the structure of the stabilizers claimed according to the invention, show a significantly less favorable behavior as a result of strong discoloration and a noticeably lower protective effect. Acquaintance Stabilizers such as compound IX or X are also clearly inferior in their stabilization; either build that Polyurethane still degrades very strongly - or its strength remains relatively good, but it discolors a lot strong.

Le A 17 887 - 24 -

709834/0780

Claims (2)

2085975 Γ ° Η, _ OH ₃₁ Claims 1J Process for stabilizing segmented polyurethane \ y elastomers against degradation and discoloration when exposed to light, characterized in that a) bisphenols of the general formula OH I \ = / IS ^ ί CH, CH, I ' CH, ^{3 3} CH, 3 5 in which R is a straight-chain or branched C ₁ -C ₁ Q-alkyl radical, a Cc-Cg-cycloalkyl radical which is unsubstituted or substituted by lower alkyl radicals or
denotes a C - C _g aralkyl radical, and b) a 2- (2'-hydroxyphenyl) benzotriazole of the general type formula 709834/0780 Le A 17 887 - 25 - in which X is hydrogen, alkyl or halogen → T is hydrogen, a Cj-C ^ -alkyl radical or an alkylene radical with Eeteroatcsen, R _{1 is} hydrogen or a Cj-Cp-alkyl radical, in amounts of 0.05-5.0 percent by weight, based to the polyurethane elastomers, the ratio of a to b being 10: 1 to 1:10, the polyurethane elastomers or the Auegange compounds which form polyurethane elastomers. 2. The method according to claim 1, characterized in that as stabilizers a) bisphenols of the general formula T <? ^H 3 <? ^H 3 in which R is a methyl, t-butyl, cyclopentyl or cyclohexyl group, and b) a 2- (2'-hydroxylphenyl) benzotriazole of the general type formula Le A 17 887 70983 ^ 0780 = N
X OH '^ Y X is hydrogen, alkyl or halogen, Y is hydrogen, a C.-C .. «- st Alky Ire or an alkyl enrest with heteroatoms, R ₁ is hydrogen or a C ₁ -C ₁ '-Alkylreat, in amounts of 0.05-5.0 percent by weight, based on the polyurethane elastomers, the weight ratio never from a to b is 10: 1 to 1:10, the polyurethane elastomers or the polyurethane elastomers forming Starting compounds are added. Le A 17 887 - 27 - 7O983A / O70O