DE1794144B2 - Stabilization of polyurethanes - Google Patents

Description

CH ₂ -X

wherein T is a tertiary alkyl radical with 4 to 2 carbon atoms, A is a primary or secondary alkyl radical with 1 to 12 carbon atoms or the radical T, R is a primary alkyl radical or aralkyl radical of 1 to 2 carbon atoms, Q is the radical A or an OR radical, X hydrogen or a radical of the formula

Alkyl radical or the radical OR (R primary alkyl or aralkyl radical with 1 to 12 carbon atoms) and

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

wherein X is hydrogen or chlorine, Y is hydrogen or an alkyl radical having 1 to 12 carbon atoms or —N-methylenphthalimido radical, R 'is hydrogen or denotes an alkyl radical with 1 to 12 carbon atoms, in amounts of 0.05 to 5.0 percent by weight (based on on polyurethane elastomers) and in a weight ratio of a) to b) such as 1:10 to 10: 1 for Stabilization of the polyurethane elastomers against the effects of light, heat and atmospheres begins.

denotes, where in the case of Q = alkyl radical the radical —CH ₂ · X is in the 6 position and in the case of Q = OR _{radical the radical —CH 2} · X is in the 5 position, and

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

HO

in which X is hydrogen, an alkyl or halogen radical, Y is hydrogen, an alkyl radical having 1 to 12C atoms or an alkylene radical with heteroatoms, R 'hydrogen or an alkyl radical with 1 to 12 carbon atoms means in amounts of 0.05 to 5.0 percent by weight (based on polyurethane elastomers) and in a weight ratio of a) to b) of 1:10 to 10: 1 to stabilize the polyurethane elastomers used against the effects of light, heat and atmospheres.

2. Use of a stabilizer mixture, consisting of

a) a sterically hindered phenol of the formula

OH

OH OCH,

^rH ^ ^C 'f | ^CH <} -CH ₂ / VC (CH * CH,

CH, Q ^

wherein Q is a primary, secondary or tertiary polyurethane, which consists of higher molecular weight polyhydroxyl compounds, Polyisocyanates and chain

Extensions in the form of foams, elastomers, coatings, foils or elastomer threads are widely used - to a certain extent ^; t of their structural components - against the action of light, but also in some cases in air at higher temperatures, unstable and their strength values are thereby degraded, with strong discoloration of the polyurethanes also being observed more frequently.

Many efforts have been made by adding known antioxidants such. B. phenol-based, a to achieve some protection against discoloration and degradation, but this stabilization is generally unsatisfactory.

So were z. B. Phenols, such as 4,4'-alkylidene-bis- (6 - tertiary - butyl - m - cresol), 2,6 - di-tertiary butyl-4- methylphenol or 4,4'-methylene - bis - (2,6 - di-tert-butylphenol), tested as stabilizers, but these either show a disturbing initial discoloration or failure of protection against discoloration when exposed to light or the atmosphere. Polyphenols such as 1,3,5-trimethyl-2,4,6-tris- (3,5-di-tert-butyl-4-hydroxybenzyl) -benzene were also used named as stabilizers (DT-AS 12 43 866). In addition, a number of phenolics became Compounds called, which together with hydroxybenzophenones to stabilize polyurethanes should be suitable (DT-AS 1106490). The effect of these phenolic stabilizers is but not sufficient, not washable or do such stabilizers have their own color, the z. B. is unsustainable for white elastomeric threads.

The use of 2- (2'-hydroxyphenyl) benzotriazoles as stabilizing additives / n polymers is known, but it is completely inadequate as a sole stabilizer. Also a combination of 2 - (T- hydroxyphenyl) - benzotriazoles and 1,3,5-trimethyl - 2,4,6 - tris - (3,5 - di-tert-butyl - 4 - hydroxybenzyl) - benzene or 1,2,4, 5 - tetramethyl - 3.6 - bis-

(3,5-ditertiary-butyl-4-hydroxybenzyl) -benzene is for Stabilization of segregated polyurethanes in the Dutch interpretation NE 65 09 745 described. These additives show a certain, but not sufficient, protective effect, and it remains the need for a highly effective, wash-resistant stabilization of elastomers, especially elastomer threads.

The invention now relates to the use of 0.05 to 5.0 percent by weight of a stabilizer ^ mixture consisting of

a) an alkoxy-substituted sterically hindered phenol and

b) a 2- (2'-hydroxyphenyl) benzotriazole for stabilization '5

of polyurethanes against exposure to light. Warmth and atmospheres. As an alkoxy substitute, hindered phenols are those of the following formula:

OH

CH, X

(D

The following formula is used as 2- (2'-hydroxyphenyl) benzotriazoles:

R '

(II)

HO

Here, X is hydrogen, an alkyl radical, a halogen radical, Y is hydrogen, an alkyl radical having 1 to I 2 carbon atoms or an alkylene radical with heteroatoms, preferably a tert-alkyl radical, e.g. B. tert-butyl, tert-amyl or tert-dodecyl radical, R 'hydrogen or an alkyl radical with 1 to 12 carbon atoms, e.g. methyl, ethyl, iso-propyl, tert-butyl, tert-amyl, tert-octyl or tert-dodecyl radical.

The mixture is used in a weight ratio of compounds a) and b) of 1:10 to 10: 1, whereby the polyurethane elastomers have a synergistically effective stabilization against discoloration and Experience degradation when exposed to light, heat and atmospheres.

Preferred compounds a) are stabilizers of the formula

OH OCH ₃

Here T is a tertiary alkyl radical with 4 to 12C atoms, ζ. B. a tert-butyl, tert-amyl, iert-.Octyl- or tert-dodecyl radical (preferably the tertiary biityl radical. A is a primary or secondary alkyl radical with 1 to 12 carbon atoms, preferably a methyl radical, or the Radical T, R is a primary alkyl radical or aralkyl radical of 1 to 12 carbon atoms or the benzyl radical, preferably a methyl radical, Q = A, preferably a methyl, tert-butyl, tert-octyl radical or isononyl radical, or an OR radical, preferably a benzyloxy or a methoxy radical, X is hydrogen or the remainder of the formula

OH

45

where in the case of Q = alkyl radical, the radical —CH ₂ · X is in position 6 and in the case of Q = OR radical the radical —CH ₂ · X is in position 5.

CH,

f CH ₂ -X

CH,

for use, where Q is a primary alkyl radical, preferably a methyl radical, a tertiary alkyl radical, preferably represents a tertiary butyl or tertiary octyl radical or a methoxy group and X represents

OH

CH ₃ remainder.

The phenolic compounds a) of the formulas 1 and 111 are compounds which are, for example by reacting 2-tert-alkyl-4-alkylphenols with ortho-hydroxymethylalkoxybenzenes in the presence Can produce catalytic amounts of strong acids with elimination of water, for example according to the following reaction equation:

OH

OCH, OH

(CH ₃ ) ₃ C

p-Toluenesulfonic acid (ΓΗ ΐ C
in boiling toluene

C (CH ₃ J ₃

C (CH ₃ J ₃

2H ₂ O

Benztriazoles of the following formula are preferably used as compound b)

HO

where X is hydrogen or a chlorine radical, Y is hydrogen or an alkyl radical having 1 to 12 carbon atoms, preferably tert-alkyl, e.g. B. tert-butyl, tert-amyl, or a —N-methylenphthalimido radical and T hydrogen or Alkyl radical with 1 to 12 carbon atoms, ζ. Β. Represents methyl, ethyl, isopropyl, tert-butyl or tert-amyl radical.

The synergistic increase in effectiveness, which compared to the use of the stabilizer mixture the use of equal amounts of the respective individual components can be achieved, from the results, as they are set out in the examples, clearly recognizable.

Also, the great improvement in the color resistance and degradation resistance of the polyurethane elastomer, which by using the alkoxy-substituted, sterically hindered phenols of the formula 1 in combination can be achieved with light stabilizers of the formula II, in comparative tests with the corresponding phenol / Sun protection agent combination, which as phenol is S, 3,5 - trimethyl - 2,4,6 - tris - (3,5 - di-tert-butyl-4-hydroxybenzyl) -benzene contains, contrasted.

It also shows that equivalent phenols, e.g. B. the bis- or trisphenols of the formula

OH

OH

CH-

(CH ₃ J ₃ C

η = 0.1, compared to the stabilizer to be used according to the invention, e.g. B. the stabilizer "A", which contains an alkoxy group instead of a hydroxyl group, show a strong inherent discoloration (yellow) on exposure to UV light, and are therefore unsuitable for stabilizing colorless polyurethanes. The following compounds, for example, are suitable as alkoxy-substituted, sterically hindered phenols of the formula I to be used according to the invention for stabilizing the polyurethanes as component a):

C (CH ₃ J ₃

2,4-dimethyl-6- (2'-hydroxy-3'-tert.-butyl-

5'-methylbenzyl) -O-benzylphenol,

2,4-dimethyl-6- (2'-hydroxy-3'-tert.-butyl-

5'-methylbenzyl) anisole,
2-methyl-4-tert.-butyI-6- (2'-hydroxy-3'-tert.-

butyl-5'-methylbenzyl) anisole, 2-methyl-4-tert.-amyl-6- (2'-hydroxy-3'-tert.-

butyl-5'-methylbenzyl) anisole, 2-methyl-4-tert.-octyl-6- (2'-hydroxy-3'-tert.-

butyl-5'-methylbenzyl) -anisoI, 2-methyl-4-isononyI-6- (2'-hydroxy-3'-tert.-butyl-5'-methylbenzyl) anisole,

2-methyl-4-tert.-dodecyl-6- (2'-hydroxy-3'-tert.-

butyl-5'-methylbenzyl) anisole, 2-methyl-4-isododecyl-6- (2'-hydroxy-3'-tert.-

butyl-5'-methylbenzyl) -anisoI, 4-methyl-2,6-bis- (2'-hydroxy-3'-tert-butyl-

5'-methylbenzyl) anisole,
4-methyl-2,6-bis (2'-hydroxy-3'-tert-amyl-

5'-methylbenzyl) anisole,
4-methyl-2,6-bis (2'-hydroxy-3'-tert.-octyl-5'-methylbenzyl) anisole,

4-methyl-2,6-bis (2'-hydroxy-3'-tert-butyl-

5'-methylbenzyl-butoxyphenol, 4-tert-butyl-2,6-bis- (2'-hydroxy-3'-tert-butyl-

5'-methylbenzyl) anisole,
4-tert-butyl-2,6-bis (2'-hydroxy-3'-tert-amyl-

5'-methy! Benzyl) anisole,
4-tert-amyl-2,6-bis- (2'-hydroxy-3'-tert-butyl-5'-methylbenzyl (-anisole.

4-tert-octyl-2,6-bis- (2'-hydroxy-3'-tert-butyl-

5'-methylbenzyl) anisole,
4-tert-dodecyl-2,6-bis- (2'-hydroxy-3'-tert-butyl-

3 ^ methylbenzyl) anisole,
4-isononyl-2,6-bis- (2'-hydroxy-3'-tert-butyl-

5'-methylbenzyl) anisole,
4-isopropyl-2,6-bis- (2'-hydroxy-3'-tert-butyl-

5'-methylbenzyl) anisole,
4-methyl-2,6-bis (2'-hydroxy-3'-tert-butyl-

5'-methylbenzyl) -o-benzyIphenol, 2,5-bis- (2'-hydroxy-3'-tert-butyl-5'-methyl-

benzyl) hydroquinone dimethyl ether, 2,5-bis (2'-hydroxy-3'-tert.-amyl-5'-methyl-

benzyl) hydroquinone dimethyl ether, 2,5-bis (2'-hydroxy-3'-tert.-octyl-5'-methyl-

benzyl) hydroquinone dimethyl ether, 2,5-bis (2'-hydroxy-3'-tert.-dodecyI-5'-methyl-

benzyl) hydroquinone dimethyl ether, 2,5-bis (2'-hydroxy-3'-tert.-butyl-5'-isopropyl-

benzyl) hydroquinone dimethyl ether, 2,5-bis (2'-hydroxy-3'-tert-butyl-5'-tert-butyl-benzyl) hydroquinone dimethyl ether.

As component b) of the synergistic stabilizer mixture are light stabilizers based on 2- (2'-hydroxyphenyl) benzotriazole, for example the following compounds, to call:

2- (2'-Hydroxy-5'-methylphenyl) -benztriazole, 2- (2'-Hydroxy-5'-methylphenyl) -5-chloro-

benzotriazole,
2- (2'-Hydroxy-3'-tert-butyl-5-methylphenyl) -

benzotriazole,
2- (2'-Hydroxy-3'-tert-butyI-5-methylphenyl) -

5-chlorobenzotriazole,
2- (2'-Hydroxy-3'-methyl-5-tert-butylphenyl) -

benzotriazole,
2- (2'-Hydroxy-3'-methyl-5-tert.-butylphenyI) -5-chlorobenzotriazole,

2- (2'-Hydroxy-3 ', 5'-dimethylphenyl) -benzotriazole, 2- (2'-Hydroxy-3', 5'-dimethylphenyl) -5-chlorobenzetri; i7ol

2- (2'-Hydroxy-3 ', 5'-ditert.-bulylphenyD-

benzotriazole,
2- (2'-Hydroxy-3 ', 5'-di-tert-butylphenyl) -

5-chlorobenzotriazole,
2- (2'-Hydroxy-3 ', 5'-ditert.-amylphenyl) -

benzotriazole,
2- (2'-Hydroxy-3 ', 5'-ditert.-amy1phenyl) -

5-chlorobenzotriazole,
2- (2'-Hydroxy-3 ', 5'-di-tert-octylphenyl) -

benzotriazole,

2- (2'-Hydroxy-3 ', 5'-di-tert-octylphenyl) -

5-chlorobenzotriazole,
2- (2'-Hydroxy-3'-N-methylenephthalimido) -

benzotriazole.

Further suitable hydroxyphenylbenzotriazoles are described, for example, in the German Auslegeschriften 12 13 408, 1213 409, 1213 410 and in the U.S. Patent 32 13 058 listed.

The elastic polyurethanes to be stabilized according to the invention, which may optionally be in foamed form, can be produced by known processes and from the known starting materials. The polyurethanes are generally made by reacting higher molecular weight polyhydroxy compounds (ζ. Β. Polyesters or polyethers with a molecular weight of about 500 to 5000, melting points preferably below 60 ^c C) and aliphatic, araliphatic or aromatic polyisocyanates (preferably aromatic diisocyanates such as tolylene diisocyanate or diphenyl methane -4,4'-diisocyanate) and so-called chain extenders, ie low molecular weight compounds (molecular weight ? .. B. 18 to 400) with two or more groups that are reactive towards isocyanate (e.g. low molecular weight diols, diamines, dihydrazides or similar compounds, such as, for example, amino alcohols, amino hydrazides, hydroxy hydrazides, semicarbazide hydrazides or even water) in single or multi-stage processes in the melt or in solvents according to a large number of known and modifiable processes.

A preferred field of application is the case of polyurethanes which having other than urethane groups by reaction of isocyanate groups with water or -NH ₂ end groups compounds (eg. As diamines, dihydrazides, carbodihydrazide or hydrazine) resulting -NH-CO-NH-groups and one in the have a substantial linear, segmented molecular structure, are soluble in highly polar solvents such as dimethylformamide or dimethylacetamide and whose characteristic segments can be characterized by the following formula excerpt:

_ _R _ _NH _ _CO —o — G — O — C — NH-R — NH-CO — HN-X — NH-CO — NH-

where R is a divalent aliphatic, araliphatic or aromatic radical (a diisocyanate), G the radical of a higher molecular weight poly hydroxyl compound with a molecular weight of 500 to 3000 and melting points below 60 ° C without their terminal hydroxyl groups (e.g. radical of a polyalkylene ether, polyester, polyacetal , Poly-N-alkyl urethane) and X is the radical of a divalent chain extender with terminal NH ₂ groups, for example an aliphatic, araliphatic, aromatic or heterocyclic radical, an —HN-CO-alkylene — CO-NH radical, an HN-CO -Arylene —CO — NH radical, a —HN — CO — NH radical, a

—NH-CO — CO-NH radical,

NH-CO-NH- (CH ₂ ) ₂ -CO-NH- radical

or represents a bond between two nitrogen atoms. Polyurethane foams can, 2nd B. under Addition of stabilizers to the starting materials (ζ. Β. Polyesters, polyethers or polyisocyanates) according to known processes and recipes (see, for example, Kunststoff-Handbuch, Vol. VII, Polyurethane, Carl Hanser Verlag, Munich, pp. 440 to 457, 504 to 531).

The stabilizers can be used with the polyurethanes in any manner more adapted to the process engineering requirements Way have been incorporated. The simplest metering results from adding the, if necessary dissolved stabilizers for solutions of the polyurethane, e.g. for the spinning, coating or coagulation purposes, preferred solutions in highly polar solvents. e.g. dimethylformamide or dimethyl sulfoxide. With the help of suitable mixing areas. like kneading or rolling, can however, the stabilizers can also be incorporated into the melts or plasticized polyurethane sheets. The stabilizers can optionally also be applied to elastomer threads together with the preparation Get applied to the surface.

Another possibility is to use the stabilizers as the starting materials for the polyurethane production add and carry out the polyurethane synthesis together with these. So are the alkoxy substituted compounds in the higher molecular weight polyhydroxy compounds (ζ. Β. polyesters or polyethers) soluble. With such

stabilizer-containing polyesters or polyethers can then corresponding polyurethane syntheses, e.g. production of foams or elastomers be performed. Also the diisocyanates or from higher molecular weight polyhydroxy compounds and NCO pre-adducts formed by (excess molar amounts) diisocyanates can be used as stabilizers be added before the formation of the poly urethane z. B. by spinning in aqueous diamine solutions, takes place. By using the stabilizers in the implementation of NC O-Vor adducts with chain extenders such as diamines, hydrazine, hydrazides or similar chains Extenders, in highly polar solvents such as dimethylformamide or dimethylacetamide, came about in many cases, surprisingly, a discoloration of the segmented polyurethanes can already be observed « prevent their synthesis. The added amount of the stabilizer mixture is 0.05 to 5 weight percent, preferably 0.2 to 5.0 percent by weight, esp or 0.3 to 3.0 percent by weight, based on the solid polyurethane substance. This is where the phenol comes in Stabilizers a) and the light stabilizers b) in a weight ratio of 1:10 to 10: 1, preferably 3: 1

up to 10: 3 and especially mixed in a ratio of 5:10 and 10: 5, for use.

By adding the claimed stabilizer mixtures to polyurethanes which contain reaction components with tertiary, aliphatically substituted amino groups in amounts of 0.02 to 1 mol, preferably 0.05 to 0.3 mol, per kilogram of elastomer substance, a certain increase in the sunscreen effect is observed. Examples of such reaction components are glycols, diamines, dihydrazides or polyesters or polyethers with tertiary amino groups, e.g. B. N, N-bis (ß - hydroxypropyl) - methylamine, N, N '- bis - (ß - hydroxyethyl) - piperazine, N, N' - dimethyl, Ν, Ν '- bis (y-aminopropyl) -äthylenediamine, N, N'-bis - ()> - aminopropyl) - piperazine or polyethers containing tertiary amino groups or polyesters containing tertiary amino groups which have been prepared using dialcohols containing tertiary amino groups.

General manufacturing instructions for the
alkoxy-substituted phenols a)

The mixture of a 2-tert-alkylphenol and an o-hydroxymethylalkoxybenzene is in the presence catalytic amounts of a strong acid, such as. B. p-Toluenesulfonic acid, in a water immiscible organic solvents, such as. B. toluene, heated to boiling on the water separator until the Dehydration has ended. The hydroxymethyl compound can optionally be in solid form, as a solution or as a melt in small portions over a longer period of time in the boiling Reaction mixture are entered. The reaction product generally falls into on cooling crystalline form and is worked up as usual (filtration, recrystallization).

Preparation of 4-methyl-2,6-bis- (2'-hydroxy-3'-tert-butyl-5-methylbenzyl) anisole (Stabilizer A)

A solution of 200 g (1.22 mol) of 2-tert-butylp-cresol and 1 g of p-toluenesulfonic acid in 500 ml of toluene is heated to the boil on a water separator. One then leaves one at 100 ^° C. within 6 hours

ίο heated solution of 100 g (0.55 mol) 1-methoxy-4-methyi-2,6-dihydroxymethylbenzene slowly drop into 150 ml of toluene. The mixture is heated for a further 3 hours to boiling, then add 1.31 petrol at about 80 ° C, the solution cools and sucks

The separated crystals stand for a few hours. 88 g are obtained

OCH,

OH

CH ₃

(Stabilizer A)

CH ₃

in the form of colorless crystals, m.p. 188 to 190 C.

Concentration of the filtrate gives a further 24 g with a melting point of 188 to 189 ° C.

The substances listed in the table below were obtained by reacting the specified starting substances produced in the appropriate molar ratios in an analogous procedure (cf. Table 1).

Table 1

stabilizer

Starting products
( ⁰ C)

Mol- Fp. ("Or

ratio stabilizers

OH

OCH

QH OH

OCHj

HO-CH ₂

approximately

CH ₂ -OH 2: 1194-197

OH

OCH ₃

(Fp. 88 to 89)
OH OCH ₃

+ ApCH ₂ - | A-CH ₃
VV

CH,

CH,

1: 1 119 to 120

CH ₃ CH ₃

(Kp. 145 to 147/14 Torr)

+ = terL-butyl.

continuation

stabilizer

OH

Starting product c

("Cl

Mol- Fp. ("Or

ratio stabilizers

OCH ₃

OH

OH

CH ₂ -OH 1: 1

172

CH

(Fp. 104 to 106)

+ = lert-butyl.
Φ = tert-octyl.

HO-CH ₂

2: 1

226

CH ₅ -OH

OCH,

(Fp. 162 to

example 1

800 parts of a polytetramethylene ether diol (molecular weight 1010), 17.4 parts of N, N-bis - (/ * - hydroxypropyl) - N - methylamine, 306.6 parts of 4,4'-diphenylmethane-4,4'-diisocyanate and 284 parts of chlorobenzene are heated to 65 to 70 ° C for 52 minutes and then cooled to room temperature. 400 parts of this NCO pre-adduct solution (1.88% NCO) were within 4 minutes into a fresh suspension, prepared by adding 15 parts of solid carbonic acid into a solution of 5.93 parts of ethylenediamine in 898 parts of dimethylformamide, with thorough stirring entered, whereby a homogeneous, viscous, pale yellowish solution is formed. This solution is through Addition of 4 percent by weight (based on solid substance) titanium dioxide (rutile) pigmented. The solution (Viscosity 423 P) is used in proportions with or without the addition of stabilizers in the proportions described in Example 4 Transferred into foils, cut them into threads and irradiated as such with UV light (fadeometer) (see table 2).

In a similar reaction to the example above, the 2 percent by weight became stabilizer not added to the finished solution afterwards

(see above), but dissolved together with the ethylenediamine in dimethylformamide and then with the NCO pre-adduct the solution made. It became a homogeneous, viscous, completely colorless solution received, which did not discolour even when exposed to air.

After casting into foils and exposure of the threads, a practically identical stabilizing effect was achieved measured against strength degradation under exposure.

Table 2

stabilizer

original
RF

(g / den)

Fadeometer exposure

Deh- 22 hours 44 hours

tion

RF stretch RF

(g / den) (%) elongation

(g / den) (%)

66 hours
RF

strain

(g / den)

88 hours

RF stretch

(g / den) (%)

Without stabilizer additives 0.60 584 <0.03 <100 not measurable -

+ 2% stabilizer A
(Component a) of the synergistic mixture)

Discoloration:

almost colorless yellow

0.60 585 0.60

Discoloration:
colorless colorless

yellow-brown yellow-brown yellow-brown

0.59 587 0.58 580 0.18 330

almost colorless almost colorless pale yellowish

continuation

stabilizer

original

Fadeomelcr exposure

RF Deh- 22 hours 44 hours 66 hours

Elongation RF Elongation RF

strain

Deh- RF Deh

tion

(g / den) (%) (g-denl (%) (g den) (%) (p / den) (%)

RF
(g-denl 88 hours

RF stretch

(g'dcn) ("/ oil

+ 2% 2- (2'-Hydroxy-3'-tert.-butyl-5'-methy! -
phenyl) -5-chlorobenzotriazole
(Component b) of the synergistic mixture

+ 1% stabilizer A
+ 1% 2- (2'-Hydroxy-3'-tert-butyl-5'-methyl-
phenyl) -5-chlorobenzotriazole
(synergistic mixture)

-I- 1%

+ 1% 2- (2'-hydroxy-

3'-tert-butyl-5'-methyl-

phenyl) -5-chlorobenzotriazole

(Mixture according to

NE-AS 6509 745)

0.39

Discoloration:

colorless yellowish

0.71

Discoloration:
colorless colorless

0.69

Discoloration:
colorless colorless

no longer
measurable

yellow

0.60 570 0.59 546 0.50 534

colorless

colorless

colorless

0.58 550 0.52 540 0.20 385

colorless

colorless

yellowish

Example 2

A mixed polyester (molecular weight 1660) of adipic acid and of the diol mixture of 1,6-hexanediol and 2,2-dimethyl propane in a molar ratio 65 6500 parts: after lstündigem dewatering at 130 ⁰ C / 10 Torr at 55 ° C with 129 parts of N, 35 N-bis (/ miydroxypropyl) - N - methylamine and 1782 parts of diphenylmethane-4,4'-diisocyanate are added and the mixture is heated in a boiling water bath (about 70 minutes) until the NCO content of the NCO pre-adduct melt is 2.22%.

In about 80 ⁰ C hsiße solution of 297.5 parts / i-Semicarbazidoalanylhydrazid

(H ₂ N · NH · CO · NH · CH ₂ · CH ₂ · CO · NH · NH ₂ ) of a 33% strength titanium dioxide paste, and then 6460 parts of the NCO pre-adduct melt are stirred in, a viscous solution (615 P / 20-C) is created.

The solution is partly with various stabilizers according to the claim of the invention or mixed with comparison substances and exposed to light in the fadeometer after spinning to form elastomer threads and the reduction in strength of the threads is determined (see Table 3). The spinning took place according to the dry spinning process by extrusion of the solution through a nozzle with 16 holes 0.2 mm in diameter into a heated shaft (220 to 230 ° C) and peeling off of the threads at a speed of about 100 m / min, and winding up at about 130 m / min.

The threads (total of about 190 den) were

820 g in 18,813 parts of dimethylformamide are then annealed for 1 hour at 130 ° C.

Table 3

Decrease in strength of elastomer threads (individual titre approx. 12 denier) after exposure to the fadeometer

original fracture
strain 480 minutes fracture
strain 900 minutes fracture
strain 1440 minutes fracture
strain Tear
firm
speed (%) Tear
firm
speed (%) Tear
firm
speed <%) Tear
firm
speed (%) (g / den) 400 (g / den) 350 (g / den) 175 (g / den) Without stabilizer 0.54 370 0.41 350 0.12 340 330 2% stabilizer A 0.55 0.50 340 0.42 195 0.33 - 2% 2- (2'-hydroxy-3 ', 5'-ditert.-
butylphenyl) -5-chlorobenzotriazole 400 0.42 390 0.15 385 - 350 1% stabilizer A
+ 1% 2- (2'-hydroxy-3 \ 5'-ditert.-
butylphenyl) -5-chlorobenzotriazole
(synergistic mixture) 0.64 0.62 0.52 0.50

° l

continuation

original fracture
strain 480 minutes fracture
strain 9CMi minutes fracture
strain 1440 minutes fracture
strain Tear
firm
speed (%) Tear
firm
speed (%) Tear
firm
speed (%) Tear
firm
speed (%) (g'den) (g the) (gden) (g the)

0.55

400

400

0.44

335

0.28

310

1% stabilizer according to DT-AS
12 43 866 + 1% (comparison test according to NE-AS 65 09 745)

After a washing treatment (3 hours in a solution of 5 g / l soap + 2 g / l soda at 60 ° C) the following values of the synergistic mixture or the mixture of the comparative test according to NE-AS 65 09 745 determined, which shows the increased wash resistance of the synergistic mixture according to the invention

Synergistic mix after
Washing (see above)

Comparative experiment after

NE-AS 65 09 745 after washing (see above)

390

340

0.54

353

0.36 310

0.35

0.12

315

190

The results show that the mixture of compounds a) and b) synergistic reinforcement experience compared to the individual compounds in the same concentration and that the stabilizing effect is significantly better than that of known stabilizer mixtures (e.g. 3. according to NE-AS 6509 745) and is better preserved after washes.

Example 3

1000 parts of a polytetramethylene ether diol (OH.Z.III), 20.6 parts of N, N-bis (/ 9-hydroxypropyl) -N-methylamine, 369 parts of diphenylmethane-4,4'-diisocyanate and 349 parts of chlorobenzene are 50 minutes heated to 65 to 70 ° C to form the NCO pre-adduct. After subsequent cooling, the is NCO content: 69%.

5.27 parts of ethylenediamine are dissolved in 895 g of DMF, with 13 parts of finely divided pigments (rutile) and then added 15 parts of solid carbonic acid. 400 parts of the NCO-

Table 4

Stir in pre-adduct solution in a few minutes, resulting in a solution at 565 P / 20 ° C. Shares the solution was each with 2% of phenol stabilizers (a) or light stabilizers or 2% of the synergistic Mixture of (a) and (b) and the mixture according to NE-AS 65 09 745 are added. Solution fractions with or without added stabilizer became each film produced in a known manner and exposed in the fadeometer (see Table 4).

The results show that the new stabilizer mixtures provide significantly improved protection show against discoloration and decrease in strength compared to the individual components.

Similar good results are obtained when using 2% mixtures of phenol stabilizers (a), which are designated in Table 1 on Columns 9 to 12 with (B), (C) and (D) and light stabilizers (b) such as - ( T - hydroxy - 3 ', 5' - ditert - amylphenyl) - benzotriazole or 2 - (2 '- hydroxy - 5 - methylphenyl) - benzotriazole in a quantitative ratio of 2: 1 to 1: 2.

additions

Fadeometer exposure
22 hours

44 hours

2% stabilizer A (component a)

2% 2- (2'-hydroxy-3'.5'-di-tert-butylphenyl) -5-chlorobenzotriazole (component b)

1% stabilizer A + 1% 2- (2'-hydroxy-3 ', 5'-di-tert-butylphenyl) -5-chlorobenzotriazole (synergistic mixture)

2% stabilizer E (component a)

I% stabilizer E + 1% 2- (2'-hydroxy-3 ', 5'-di-tert-butylphenyl) -5-chlorobenzotriazole (synergistic mixture) foils yellow

Strength completely degraded

Colorless foil
Maintain strength

Foil yellowish
Strength largely
reduced

Colorless foil
Maintain strength

Foil yellowish
Strength largely
obtain

Colorless foil
Maintain strength

Foils yellow-brown
destroyed

Foil almost colorless
Strength largely
obtain

Foil yellow
Strength degraded

Colorless foil
Maintain strength

Foil yellowish
Strength largely
obtain

continuation

additions

Fadeometer exposure
22 hours

2% 2- (2'-Hydroxy-3'-N-methylenephthalimido) benzotriazole (Component b)

1% Stabilizer E + 1% 2- (2'-Hydroxy-3'-N-methylenephthalimido) -benztriazole (synergistic mixture)

Example 4

800 parts of a polytetramethylene ether diol (OH.Z.111) are mixed with 17.4 parts of N, N-bis (/? - hydroxypropyl) -N-methylamine, 306.6 parts of diphenylmethane-4,4'-diisocyanate and 284 parts of chlorobenzene 50 Heated minutes to 65 to 70 ⁰ C and then cooled to room temperature. 800 parts of the NCO pre-adduct solution obtained (1.9% NCO) are stirred with a solution of 38.7 parts of 4,4'-diammodiphenylmethane in 1872 parts of dimethylformamide and, after 12 hours, 338 parts of diphenylmethane-4,4'-diisocyanate are added , whereby a viscous solution (102P / 20 ° C) is obtained, which is mixed with 1 part of acetic anhydride per 100 parts of solution, yellowish film
Strength largely
obtain

Colorless foil
Maintain strength

44 hours

Yellow foil strength degraded

Foil almost colorless strength largely obtain

will. The solution is made by adding 4% titanium dioxide (rutile) - based on the solid substance - pigmen-

Shares of the above solution are 2% of the erfindunesgemäße Stabilizer mixture or, for comparison, each with 2% of components a) and b) as well as the mixture according to NE-AS 65 09 745 added.

The solutions with or without a stabilizer are brushed onto glass plates and kept at 100 ° C. for 60 minutes dried. The approximately 0.15 to 0.20 mm thick films are made into threads by means of a foil cutting machine cut from about 300 the thread size and then irradiated with UV light for 0.22, 44.66 hours (Table 5).

Table 5

original

Tear resistance

(g / den)

Elongation at break hours
Tear fracture

strength

(g / den) elongation

Without stabilizer

2% stabilizer A 0.66 605

(Sub-component of the synergistic mixture)

2% 2- (2'-hydroxy-3'-tert-butyl-0.66,610 5'-nv: thylphenyl) -5-chlorobenzotriazole (Sub-component of the synergistic mixture)

1% stabilizer A 0.66 620

+ 1% 2- (2'-hydroxy-3'-tert-butyl-5'-methylphenyl) -5-chlorobenzotriazole (synergistically effective mixture)

1% 0.65 610

+ 1% 2- (2'-Hydroxy-3'-tert.-butyI-5'-methylphenyl) -5-chlorobenzotriazole (comparison test according to
NE-AS 65 Oi) 745)

The synergistic mixture shows a significantly longer effectiveness compared to the individual components and is clearly superior to the stabilizer mixture according to NE-AS 65 09 745.

In game 5

800 parts of a polytetramethylene ether diol (OHZlIl) are mixed with 18.0 parts of N, N-bis - (^ - hydroxypropyl) -N-methylamine, 394.5 parts diphenyl

<0.05 yellow-brown

0.60 colorless

0.16 yellowish

0.67 colorless

0.54 colorless 44 hours

Tear fracture

strengthening elongation
speed

(g / den) (%)

yellow-brown

0.53 621
colorless

no longer

measurable

yellowish

0.68
colorless

0.33
colorless

604

604

66 hours

Tear resistance

Elongation at break

(g / den) <%)

brownish yellow

0.17 400 colorless

no longer

measurable

yellow

0.53 colorless

0.16 yellowish

610

387

methane-4,4'-diisocyanate and 304 parts of chlorobenzene is heated 40 minutes for 8O ⁰ C, an NCO preadduct formed containing, after cooling to room temperature 3.58% NCO.

Solution I.

404 parts of the NCO pre-adduct solution are mixed with 3.30 parts of water in 889 parts of dimethylformamide stirred at room temperature, the solution

Table 6

Tensile strength (in g / den)
Exposure (in hours)

44

66

88

Without addition

0.68 0.27 no more

measurable
0.70 0.69 0.30 0.27

yellow discolored after about an hour and a highly viscous and strongly yellow colored after 24 hours Solution results. When the solution is spun by the customary dry spinning process, it turns yellow Obtain elastomer threads.

Solution 11

404 parts of the NCO pre-adduct solution are with 3.30 parts of water and 4.87 parts of stabilizer A (1.5 percent by weight) and 1.63 parts (0.5 percent by weight) of the light stabilizer 2- (2'-hydroxy-3 ', 5'-di-tert-amylphenyl) -benzotriazole in 890 parts Dimethylformamide stirred at room temperature, whereby after 24 hours a highly viscous, completely colorless solution is obtained, which at Spinnang colorless elastomer threads are obtained using conventional dry spinning processes, which also apply to exposure or hot air treatment a much better stability against discoloration or strength degradation than that Have threads from solution I.

Solution 1 is mixed with 2 percent by weight of the mixture of 1.5% stabilizer A and 0.5% light stabilizer (see above), weakly colored elastomer threads are obtained that are exposed to light or hot air treatment (e.g. 1 hour / 150 ° C) much more stable are as threads from solution I without stabilizer salt.

Example 6

800 parts Polytetramethylenätherdiol, molecular weight 1010 are 4,4'-diphenylmethane diisocyanate with 297 parts and 223 parts of chlorobenzene of the NCO preadduct heated 38 minutes at 80 ⁰ C to form. Stirring 419 parts of the pre-adduct into a solution of 11.56 parts of carbodihydrazide in 916 parts of dimethylformamide at about 60 ° C. gives a highly viscous (552 P) solution which is pigmented _{with 4% TiO 2.} This solution is partly mixed with 1 percent by weight of stabilizer A (based on solid substance), partly left without stabilizer. Films obtained from the solutions show the following values after fadeometer exposure:

N-methylamine and 178.8 parts of diphenylmethane-4,4'-diisocyanate in 198 parts of dimethylformamide at 45 to 5O ⁰ C heated until the NCO content of 2.74% NCO preadduct (in the solid) is.

In a solution of 27.1 parts /? - semicarbazidoalanylhydrazide in 54.2 parts of water after diluting the solution with 1347 parts of dimethylformamide 645 parts of the NCO pre-adduct solution entered, a solution (400 P) being formed which

ίο is then pigmented with 4% TiO.

Substance used according to the invention, together with a known type V UV stabilizer or VI:

OH

OCH, OH

Comparative substances according to the prior art: 01 to IV).

II. 2,2'-methylenebis (4-methyl-6-tert-butylphenol) OH OH

(CH ₃ J ₃ C-Vy-CH ₂

C (CH ₃ ),

CH ₃

III. 4,4'-thio-bis- (6-tert-butyl-m-cresol)
CH ₃ C (CH ₃ ) ₃

4 °

HO

(CH ₃ ) ₃ C

IV. 2,2'-Butylidene-bis- (6-tert-butyl-pK: resol)
(CH ₃ ) ₃ C- ^

C ₃ H ₇
CH ₃ CH ₃

+ UV stabilizers as synergists.

V. 2- (3 '-Hydroxyphenyl) -benztriazole
A.

+ 2% stabilizer A

+ (I ⁰ Zo Stabilisa- 0.70 0.69 0.61 0.59 0.52 ^5S tor A + Γ / ο
2- (2'-hydroxytert-butyl-5'-methyl-
phenyl) -5-chloro-

benzotriazole ^ VI. 5-chloro-2- (2'-hydroxy-3,5-di-tert-butylphenyl) -

benzotriazole

HO

Test report
Manufacture of the polyurethane

600 parts of a mixed polyester of adipic acid and the diol mixture, consisting of 1,6-hexanediol and 2,2-dimethylpropanediol-1,3 (molar ratio 65:35) are with 12.05 parts N, N-Bis - (/ Miydro>; ypropyl) -

QCH ₃ J ₃

C (CH ₃ J ₃

Experimental scheme

The following stabilizers or stabilizer-ZUV absorber mixtures are added to the solution (Percentage by weight based on solids content).

1. according to the invention

a) 2% I,

b) H / o I + 1% V,

c) 1% I + 1% VI.

2. a) 2% comparison substance II,

b) 1% II + 1% V,

c) 1% II 4- 1% Vl.

3 a) 2% comparison substance 111, b) l% 111 + l ^{c /} o V,

c) 1% III + 1% VI.

4 a) 2% comparison substance IV,

b) 1% IV + 1% V,

c) 1% IV + 1% VI.

5. 2% V.

6.2% VI.

The solutions were poured and dried to form films at 100.degree. Foil strips about 1 cm wide were exposed simultaneously for 8, 15, 22, 30, 44, 66 and 88 hours and the discoloration was assessed.

Exposure results

To
8 hours 15 hours 22 hours 44 hours 66 hours 88 hours Without stabilizer slightly discolored pale yellowish
discolored pale yellowish
discolored yellowish brownish yellow-brown yellow-brown c) 1% I + 1% VI
(according to the invention) colorless
colorless
colorless colorless
colorless
colorless almost colorless
colorless
colorless pale yellowish
almost colorless
almost colorless pale yellowish
almost colorless
almost colorless yellowish brown
yellowish
weak-
yellowish Comparative experiments
2. a) 2% H
c) 1% II + 1% Vl (lemon) yellowish
(lemon) yellowish
(lemon) yellowish (lemon) yellow
(lemon) yellow
(lemon) yellow gelf
yellow
yellow intense yellow
intense yellow
intense yellow most intense yellow
most intense yellow
most intense yellow most intense yellow
most intense yellow
most intense yellow 3. a) 2% III
c) Γ / ollI + 1% VI pale brownish
very
slightly brownish
very
slightly brownish brownish
pale brownish
pale brownish brownish
brownish
brownish yellow-brown
yellow-brown
yellow-brown brownish yellow
brownish yellow
brownish yellow brownish yellow
brownish yellow
brownish yellow 4. a) 2% IV weak (citric
yellowish
weak (citric
yellowish
weak (citric
yellowish yellowish
yellowish yellow
yellow intense yellow
intense yellow intense yellow
intense yellow most intense yellow
most intense yellow c) I% IV + 1% VI slightly discolored yellowish yellow intense yellow intense yellow most intense yellow 5. 2% V slightly discolored slightly discolored pale yellow brown yellowish brownish yellowish brown yellow-brown 6. 2% Vl slightly discolored pale yellow brown yellowish brownish yellowish brown yellow-brown

judgement

The results show that the stabilizer mixture used according to the invention has considerable advantages compared to known stabilizers or their mixture with UV absorbers. The one in the citation named stabilizers show severe discoloration on exposure of polyurethanes. Samples II and IV are intense yellow and the

Sample III is intense brown while the claimed one Use results in significantly better protection. Also by mixing it with UV absorbers of type V, VI could not achieve any advantageous result with the comparative stabilizers (II to IV) while the advantages of mixtures of I and UV absorbers are clear here and in the examples be proven.

Claims (1)

Patent claims: 1. Use of a stabilizer mixture, consisting of a) an alkoxy-substituted, sterically hindered phenol of the formula OH