WO2002042368A2 - Method for stabilizing polyolefins - Google Patents

Abstract

A method for the production of polyolefins which are subjected to the effect of water and stabilized against visible and ultraviolet light, wherein light stabilizers are added to the polyolefin. The inventive method is characterized in that the light stabilizers are selected from the following compounds a) d): a) cyanoacrylic acid esters of formula 1, b) 4,4 diarylbutadienes of formula II, c) benzophenones of formula III, d) cinnamic acid esters of formula IV, the variables having the meaning cited in the description.

Description

 Process for stabilizing polyolefins

The invention relates to a process for the preparation of polyolefins which are exposed to the action of water and which are stabilized against visible and ultraviolet light, in which light stabilizers are added to the polyolefin.

The invention further relates to methods for reducing the yellowing of polyolefins stabilized against visible and ultraviolet light, which are exposed to the action of water.

In addition, when exposed to water, the invention relates to yellowing-resistant polyolefins which are stabilized against visible and ultraviolet light, and to moldings, foils and foams made from these polyolefins.

Finally, the invention relates to the use of light stabilizers in polyolefins which are exposed to the action of water.

Polyolefins, especially the homo- and copolymers of ethylene and propylene, are usually used against visible and

25 traviolette (UV) light stabilized to counteract the damage to the polymer by photo-oxidation. In 1988 approx. 75% of the light stabilizers (light stabilizers) used in plastics were used in polyolefins {R. Gächter, H. Müller, Plastics Additives Handbook, 4th edition, Hanser Verlag Munich

30 1993, reprint 1996, p. 130).

Polyolefins that contain light stabilizers and are exposed to water usually show increasing yellowing over time: initially opaque, white or

35 light color changes under the influence of water to yellowish to brownish. This yellowing is undesirable for aesthetic reasons. Polyolefins are exposed to water in numerous applications, e.g. for pipes for drinking water and waste water, fittings for drinking and waste water

40 tubes, for packaging and foils, in particular packaging for cosmetics (e.g. shampoo, creams, other water-containing cosmetic products) and packaging and foils for food (e.g. fruit, vegetables, meat and other water-containing foods), for drinking water bottles, in the entire outdoor area, e.g. Gartenmö-

45 bei, windows and fittings, luminaire housings, vehicle exterior parts, etc. The disadvantageous yellowing complicates or prevents them Use of polyolefins in applications where the plastic is exposed to water.

The task was to remedy the disadvantages described. In particular, the object was to provide a process with which light-stabilized polyolefins can be obtained which, under the action of water, yellow considerably less than the light-stabilized polyolefins of the prior art.

There was also the task of providing light-stabilized polyolefins which show a significantly lower yellowing in water than the known stabilized polyolefins.

Accordingly, the process defined at the outset for the production of polyolefins was found. It is characterized in that the light stabilizers are selected from the following compounds a) to d)

a) Cyanoacrylic acid esters of the formula I

With

R ¹ and R ^ ^{1 are} hydrogen, -CC o-alkyl, C -Coo "alkenyl, C ₃ -Cιo-cycloalkenyl, Cι-Cι alkoxy, aryl, hetero-aryl, optionally substituted,

X is ethyl, 2-ethylhexyl, pentaerythrityl, propane-1,2,3-triyl, polyalkylene glycol radical, n is an integer from 0 to 3, m is an integer from 1 to 4,

b) 4,4-diarylbutadienes of the formula II

in which the diene system in the Z, Z; Z, E; E, Z or E, E configuration or a mixture thereof and in which the variables have the following meaning independently of one another:

R ¹ and R ^{2 are} hydrogen, -CC o ~ alkyl, C -C -o alkenyl, C ₃ -Cι ₀ - cycloalkyl, C ₃ -Cιo ^_ cycloalkenyl, Cι ~ Cι -alkoxy, Cι-C o-alkoxycarbonyl, Cι- Cι alkylamino,

-CC -dialkylamino, aryl, heteroaryl, optionally substituted, water-solubilizing substituents selected from the group consisting of carboxylate, sulfonate or ammonium residues;

R ^{3 is} hydrogen, COOR ⁵ , COR ⁵ , CONR ⁵ R ⁶ , CN,

0 = S (-R ⁵ ) = 0, 0 = S (-0R ⁵ ) = 0, R ⁷ 0-P (-0R ⁸ ) = 0, -C-C ₂₀ alkyl, C ₂ -C ₁₀ alkenyl, C ₃ -Cι ₀ -cycloalkyl, C ₇ -Cιo-bicycloalkyl, C ₃ -Cιo ^_ cycloalkenyl,

C ₇ -Cιo-bicycloalkenyl, aryl, heteroaryl, optionally substituted;

R ⁴ COOR ⁶ , COR ⁶ , CONR ⁵ R ⁶ , CN, 0 = S (-R ⁶ ) = 0, 0 = S (-0R ^e ) = 0, R ⁷ 0-P (-0R ⁸ ) = 0

-C-C ₂ o-alkyl, C ₂ -Cι ₀ -alkenyl, C ₃ -Cι ₀ -cycloalkyl, C ₇ -Cιo-bicycloalkyl, C ₃ -Cιo-cycloalkenyl, C ₇ -Cιo-bicycloalkenyl, aryl, heteroaryl, optionally substituted;

R ⁵ to R ^{8 are} hydrogen, -CC ₂₀ alkyl, C ₂ -C ₁₀ alkenyl,

C ₃ -Cιo-cycloalkyl, C ₇ -Cιo-bicycloalkyl, C ₃ -Cι ₀ -cycloalkenyl, C ₇ -Cιo-bicycloalkenyl, aryl, heteroaryl, optionally substituted;

n 1 to 3,

where the variables R ³ to R ⁸ together, in each case together with the carbon atoms to which they are bonded, can together form a 5- or 6-ring which can optionally be fused further, c) Benzophenones of the formula III

0

With

Y is hydrogen, COOR ¹ or OH,

R ¹ Z OR ¹ or N

A is hydrogen or S0 ₃ H,

wherein R ¹ and R ^{11 have} the meaning given in a), and

d) cinnamic acid esters of the formula IV

where R ¹ , R ¹¹ and n have the meaning given in a).

The process defined at the outset for reducing yellowing was also found. It is characterized in that the light stabilizers used are selected from the compounds as defined above under a) to d).

Furthermore, the invention relates to the polyolefins defined at the outset, containing as light stabilizers at least one of the compounds a) to d) as defined above, and to moldings, films and foams made from these polyolefins.

Finally, the invention relates to the use of light stabilizers mentioned at the outset, these being selected from the compounds a) to d) as defined above.

Water includes all types of water, especially drinking water, domestic and commercial waste water, distilled, deionized and demineralized water, rainwater, groundwater, Surface water (rivers, lakes), sea water, spring water as well as mineral and medicinal water.

All polymers of olefins are suitable as polyolefins, in particular polymers of ethylene, propylene, but-l-ene, isobutylene and 4-methylpentene.

Polymers are understood to mean both homopolymers and copolymers of one of the monomers mentioned as the main monomer and other monomers as comonomers.

Preferred polyolefins are the homopolymers and copolymers of ethylene and the homopolymers and copolymers of propylene.

Ethylene polymers:

Suitable polyethylene (PE) homopolymers include:

PE-LD (LD = low density), available according to the high pressure process (ICI) at 1000 to 3000 bar and 150 to 300 ° C with oxygen or peroxides as catalysts in autoclaves or tubular reactors. Heavily branched with branches of different lengths, crystallinity 40 to 50%, density 0.915 to 0.935 g / cm ³ , average molecular weight up to 600,000 g / mol.

PE-LLD (LLD = linear low density), available with metal complex catalysts in the low pressure process from the gas phase, from a solution (e.g. petrol), in a suspension or with a modified high pressure process. Weakly branched with unbranched side chains, molecular weights higher than with PE-LD.

PE-HD (HD = high density), available according to the medium pressure (Phillips) and low pressure (Ziegler) process. According to Phillips at 30 to 40 bar, 85 to 180 ° C, chromium oxide as a catalyst, molar masses about 50,000 g / mol. According to Ziegler at 1 to 50 bar, 20 to 150 ° C, titanium halides, titanium esters or aluminum alkyls as catalysts, molar mass about 200,000 to 400,000 g / mol. Carried out in suspension, solution, gas phase or mass. Very weakly branched, crystallinity 60 to 80%, density 0.942 to 0.965 g / cm ³ .

PE-HD-HMW (HMW = high molecular weight), available according to the Ziegler, Phillips or gas phase method. High density and high molecular weight. PE-HD-UHMW (UHMW = ultra high molecular weight) available with modified Ziegler catalyst, molecular weight 3,000,000 to 6,000,000 g / mol.

Polyethylene, which is produced in a gas phase fluidized bed process using (usually supported) catalysts, e.g. Lupolen® (Elenac).

Polyethylene, which is produced using metallocene catalysts, is particularly preferred. Such polyethylene is e.g. commercially available as Luflexen (Elenac). The metal ozone catalyst system is described in more detail below.

The following compounds of the general formula are suitable as metallocene complexes:

MX ₂

/

Z

in which the substituents have the following meaning:

M titanium, zirconium, hafnium, vanadium, niobium or tantalum,

X fluorine, chlorine, bromine, iodine, hydrogen or Ci bis

Cio-alkyl,

R ⁸ to R ^{12 are} hydrogen, Ci- to Cio-alkyl, 5- to 7-membered

Cycloalkyl, which in turn can carry a C ₁ -C 10 -alkyl as a substituent, C ₆ - to cis-aryl or aryl-alkyl, where optionally two adjacent radicals together can represent cyclic groups having 4 to 15 C atoms or Si ( R ¹³ ) ₃ with

R ^{13 is} Ci- to Cio-alkyl, C ₃ - to -CC ₀ cycloalkyl or C ₆ - to cis-aryl,

being the leftovers

R ¹⁴ to R ¹⁸ hydrogen, Cι ~ to Cio-alkyl, 5- to 7-membered

Cycloalkyl, which in turn can carry a C ₁ -C 10 -alkyl group as a substituent, is C ₆ - to Cis-aryl or arylalkyl, and where appropriate two adjacent radicals together can also represent cyclic groups having 4 to 15 C atoms , or Si (R ¹⁹ ) ₃ with

R ¹⁹ Ci to Cio alkyl, C ₆ to C ₅ aryl or C ₃ to Cio cycloalkyl,

or wherein the radicals R ¹¹ and Z together form a group -R ²⁰ -A- in which

R22 _R 22 _R 22 R22

_R 20 _M j, _{M3 M3 M3 CR2} 3 _f

R21 _R 21 _R 21 _R 21

R ²² R2 _R 22 _R 22

C 'OM ³ , CC'

R ²¹ R21 _R 21 _R 21

= BR ²² , = AIR ²² , -Ge-, -Sn-, -0-, -S-, = SO, = S0 ₂ , NR ²² , = CO, = PR ²² or = P (0) R ²² ,

wherein R ²¹ , R ²² and R ^{23 are the} same or different and a hydrogen atom, a halogen atom, a Cι-Cιo-alkyl group, a Cι-Cιo-fluoroalkyl group, a C ₆ -Cιo-fluoroaryl group, a C _ß -Cio aryl group, a Cι-Cιo ~ alkoxy group, a

C ₂ -Cιo-alkenyl group, a C ₇ -C ₄ o-arylalkyl group, a C ₈ -C ₄ o-arylalkenyl group or a C -C ₄ o-alkylaryl group, or where two adjacent radicals each have one with the atoms connecting them Form ring, and M ^{3 is} silicon, germanium or tin,

A 0, - S, .NR ²⁴ or PR ²⁴ mean with

R ²⁴ Ci- to Cio-alkyl, C ₆ - to C ₁₅ -aryl, C ₃ - to Cι ₀ -cycloalkyl, alkylaryl or Si (R ²⁵⁾ _3,

R ^{25 is} hydrogen, -C ~ to Cio-alkyl, C ₆ - to cis-aryl, which in turn can be substituted with Ci- to C ₄ -alkyl groups or C ₃ - to Cio-cycloalkyl

or wherein the radicals R ¹¹ and R ¹⁷ together form a group -R ²⁰ -.

Particularly suitable metallocene complexes are, for example, in the

DE-A 198 06 435, page 3, line 68 to page 5, line 67. It is expressly referred to the passage mentioned.

Such complex compounds can be synthesized according to methods known per se, the reaction of the appropriately substituted cyclic hydrocarbon anions with halides of titanium, zirconium, hafnium, vanadium, niobium or tantalum being preferred.

Examples of corresponding manufacturing processes include in the Journal of Organometallic Chemistry, 369 (1989), 359-370.

Mixtures of different metallocene complexes can also be used.

As a rule, the metallocene complexes are activated by an

Connection activated. Suitable activators are in particular

Compounds that form metallocenium ions.

Suitable metallocenium ion-forming compounds are in particular complex compounds selected from the group consisting of strong, neutral Lewis acids, the ionic compounds with Lewis acid cations and the ionic compounds with Bronsted acids as the cation.

Compounds of the general formula are strong, neutral Lewis acids M ⁴ X ^X X ² X ³

preferred in the

M ^{4 is} an element of III. Main group of the periodic table means, in particular B, Al or Ga,

χi, X ² and X ³ for hydrogen, Ci- to Cio-alkyl, CQ- to Cis-aryl, alkyl-aryl, arylalkyl, haloalkyl or haloaryl, each with 1 to 10 carbon atoms in the alkyl radical and 6 to 20 carbon atoms are in the aryl radical or fluorine, chlorine, bromine or iodine, in particular for haloaryls, preferably for pentafluorophenyl.

Compounds of the general formula are ionic compounds with Lewis acid cations

[(Y ^{a +} ) QιQ ₂ --- Q _z ] ^{d +}

suitable in which

an element of the I. to VI. Main group or the I. to VIII. Subgroup of the periodic table means

Q to Q _z for simply negatively charged residues such as Ci to

C ₂₈ alkyl, C _& - to -C ₅ aryl, alkylaryl, arylalkyl, haloalkyl, haloaryl each with 6 to 20 C atoms in the aryl and 1 to 28 C atoms in the alkyl radical, Cι ~ to Cio-cycloalkyl, which may optionally be substituted by C 1 -C 10 -alkyl groups, halogen,

Ci to C ₈ alkoxy, C ₆ - to C-aryloxy, silyl or mercaptyl groups

a stands for integers from 1 to 6, z stands for integers from 0 to 5 d corresponds to the difference a-z, whereby d is greater than or equal to 1.

Carbonium cations, oxonium cations and sulfonium cations as well as cationic transition metal complexes are particularly suitable. The triphenylmethyl cation, the silver cation and the 1, 1 '-dimethylferrocenyl cation should be mentioned in particular. They preferably have non-coordinating counterions, in particular boron compounds, as also mentioned in WO-A 91/09882, preferably tetrakis (pentafluorophenyl) borate. Ionic compounds with Bronsted acids as cations and preferably also non-coordinating counterions are mentioned in WO-A 91/09882, the preferred cation is N, N-dimethylanilinium.

All commercially available ethylene copolymers are suitable as ethylene copolymers, for example Luflexen® types (Elenac), Nordel® and Engage® (Dow, DuPont). Suitable comonomers are all -olefins having 3 to 10 carbon atoms, in particular propylene, but-1-ene, hex-1-ene and oct-1-ene, and also alkyl acrylates and methacrylates with 1 to 20 carbon atoms in the alkyl radical , especially butyl acrylate. Other suitable comonomers are dienes such as Butadiene, isoprene and octadiene and dicyclopentadiene.

They are usually statistical copolymers or block or impact copolymers.

Block or impact copolymers of ethylene and comonomers are polymers in which, in the first stage, a homopolymer of the comonomer or a random copolymer of the comonomer is prepared with up to 15% by weight, preferably up to 6% by weight, of ethylene and then in in the second stage, a comonomer-ethylene copolymer with ethylene contents of 15 to 80% by weight was polymerized. As a rule, so much of the comonomer-ethylene copolymer is polymerized in that the copolymer produced in the second stage has a proportion of 3 to 60% by weight in the end product.

The polymerization for producing the ethylene-comonomer copolymers can be carried out using a Ziegler-Natta catalyst system. In particular, catalyst systems are used which, in addition to a titanium-containing solid component, also have cocatalysts in the form of organic aluminum compounds and electron donor compounds.

However, catalyst systems based on metal ocene compounds or based on polymerization-active metal complexes can also be used.

Propylene polymers:

Under the designation polypropylene, both

Homopolymers and copolymers of propylene can be understood.

Copolymers of propylene also contain minor amounts

Propylene copolymerizable monomers, for example C ₂ -C ₈ alk-1-enes such as, inter alia, ethylene, but-1-ene, pent-1-ene or

Hex-l-ene. Two or more different comonomers can also be used. Suitable polypropylenes include homopolymers of propylene or copolymers of propylene with up to 50% by weight of other alk-1-enes polymerized in with up to 8 carbon atoms. The copolymers of propylene are statistical copolymers or block or impact copolymers. If the copolymers of propylene have a random structure, they generally contain up to 15% by weight, preferably up to 6% by weight, other alk-1-enes with up to 8 C atoms, in particular ethylene, but-1 -en or a mixture of ethylene and but-l-ene.

Block or impact copolymers of propylene are polymers in which, in the first stage, a propylene homopolymer or a random copolymer of propylene with up to 15% by weight, preferably up to 6% by weight, of other alk-1-enes with up to produces to 8 carbon atoms and then in the second stage a propylene-ethylene copolymer with ethylene contents of 15 to 80 wt .-%, the propylene-ethylene copolymer additionally other C ₄ -C ₈ -alk-1-ene may contain, polymerized. As a rule, so much of the propylene-ethylene copolymer is polymerized in that the copolymer produced in the second stage has a proportion of 3 to 60% by weight in the end product.

The polymerization for the production of polypropylene can be carried out using a Ziegler-Natta catalyst system. In particular, catalyst systems are used which, in addition to a titanium-containing solid component a), also have cocatalysts in the form of organic aluminum compounds b) and electron donor compounds c).

However, catalyst systems based on metal ocene compounds or based on polymerization-active metal complexes can also be used.

In particular, conventional Ziegler-Natta catalyst systems contain a titanium-containing solid component a), i.a. Halides or alcohols of trivalent or tetravalent titanium, also a halogen-containing magnesium compound, inorganic oxides such as silica gel as a carrier and electron donor compounds c). In particular, carboxylic acid derivatives and ketones, ethers, alcohols or organosilicon compounds are suitable as such.

The titanium-containing solid component can be prepared by methods known per se. Examples include EP-A 45 975, EP-A 45 977, EP-A 86 473, EP-A 171 200, GB-A 2 111 066, US-A 4 857 613 and US Pat US-A 5 288 824 described. The method known from DE-A 195 29 240 is preferably used.

In addition to trialkyl aluminum, suitable aluminum compounds b) are also those compounds in which an alkyl group has been replaced by an alkoxy group or by a halogen atom, for example by chlorine or bromine. The alkyl groups can be the same or different. Linear or branched alkyl groups are possible. Trialkylaluminum compounds are preferably used, the alkyl groups of which each have 1 to 8 carbon atoms, for example trimethylaluminum, triethylaluminium, tri-isobutylaluminum, trioctylaluminum or methyldiethylaluminum or mixtures thereof.

In addition to the aluminum compound b), electron donor compounds c) such as mono- or polyfunctional carboxylic acids, carboxylic anhydrides or carboxylic acid esters, furthermore ketones, ethers, alcohols, lactones, and organophosphorus and organosilicon compounds are generally used as further cocatalyst, the electron donor compounds c) being identical or can be different from the electron donor compounds used to produce the titanium-containing solid component a).

Instead of Ziegler-Natta catalyst systems, metallocene compounds or polymerization-active metal complexes can also be used for the production of polypropylene.

Metallocenes are to be understood here as meaning complex compounds of metals from subgroups of the periodic table with organic ligands, which together with compounds forming metallocenium ions result in effective catalyst systems. The metallocene complexes are generally supported in the catalyst system for use in the production of polypropylene. Inorganic oxides are frequently used as carriers, but organic carriers in the form of polymers, for example polyolefins, can also be used. Preference is given to the inorganic oxides described above, which are also used to prepare the titanium-containing solid component a).

Typically used metallocenes contain titanium, zirconium or hafnium as central atoms, zirconium being preferred. In general, the central atom is bonded via a π bond to at least one, usually substituted, cyclopentadienyl group and to further substituents. The further substituents can be halogens, hydrogen or organic radicals, where fluorine,

Chlorine, bromine, or iodine or a -CC-alkyl group are preferred. The cyclopentadienyl group can also be part of a corresponding heteroaromatic system.

Preferred metallocenes contain central atoms which are bonded to two substituted cyclopentadienyl groups via two identical or different π bonds, those which are particularly preferred in which substituents of the cyclopentadienyl groups are bonded to both cyclopentadienyl groups. In particular, complexes are preferred whose substituted or unsubstituted cyclopentadienyl groups are additionally substituted by cyclic groups on two adjacent C atoms, it being possible for the cyclic groups to also be integrated in a heteroaromatic system.

Preferred metallocenes are also those which contain only one substituted or unsubstituted cyclopentadienyl group, but which is substituted by at least one radical which is also bonded to the central atom.

Suitable metallocene compounds are, for example, ethylene bis (indenyl) zirconium dichloride, ethylene bis (tetrahydroindenyl) zirconium dichloride, diphenylmethylene-9-fluorenylcyclopentadienylzirconium dichloride, dimethylsilane diylbis (-3-tert. Butyl-5-methylcyclopentirienium)

Dirnethylsilanediyl (2-methyl-4-azapentalen) (2-methyl-4 (4'-methylphenyl) -indenyl) zirconium dichloride,

Dimethylsilanediyl (2-methyl-4-thiapentalen) (2-ethyl-4 (4 't-butylphenyl) -indenyl) zirconium dichloride, ethanediyl (2-ethyl-4-azapentalen) (2-ethyl-4 (4' - tert-butylphenyl) -indenyl) -zirconium dichloride,

Dimethylsilanediylbis (2-methyl-4-azapentalen) zirconium dichloride, dimethylsilanediylbis (2-methyl-4-thiapentalen) zirconium dichloride, dimethylsilanediylbis (-2-methylindenyl) zirconium dichloride, dimethylsilanediylbis (-2) methyldichloride -4-phenylindenyl) zirconium dichloride,

Dimethylsilanediylbis (-2-methyl-4-naphthylindenyl) zirconium dichloride, dimethylsilanediylbis (-2-methyl-4-isopropylindenyl) zirconium dichloride or

Dimethylsilanediylbis (-2-methyl-4, 6-diisopropylindenyl) zirconium dichloride and the corresponding dirnethyl zirconium compounds. The metallocene compounds are either known or can be obtained by methods known per se. Mixtures of such metallocene compounds can also be used for catalysis, furthermore the metallocene complexes described in EP-A 416 815.

The metallocene catalyst systems also contain compounds which form metal ocenium ions. Strong, neutral Lewis acids, ionic compounds with Lewis acid cations or ionic compounds with Bronsted acids as the cation are suitable. Examples include tris (pentafluorophenyl) borane, tetrakis (pentafluorophenyl) borate or salts of N, N-dimethylanilinium. Open-chain or cyclic alumoxane compounds are also suitable as metallocenium ion-forming compounds. These are usually produced by reacting trialkyl aluminum with water and are generally in the form of mixtures of different lengths, both linear and cyclic chain molecules.

In addition, the metallocene catalyst systems can organometallic compounds of the metals of I., II. Or III. Main groups of the periodic table contain such as n-butyl lithium, n-butyl-n-octyl magnesium or tri-iso-butyl aluminum, triethyl aluminum or trimethyl aluminum.

The polypropylenes are prepared by polymerization in at least one, often also in two or more reaction zones connected in series (reactor cascade), in the gas phase, in a suspension or in a liquid phase (bulk phase). The usual reactors used for the polymerization of C ₂ -C ₈ -alk-1-enes can be used. Suitable reactors include continuously operated stirred tanks, loop reactors or fluidized bed reactors. The size of the reactors is not essential. It depends on the output that is to be achieved in or in the individual reaction zones.

In particular, fluidized bed reactors and horizontally or vertically stirred powder bed reactors are used as reactors. The reaction bed generally consists of the polymer of C ₂ -C ₈ -alk-1-enes, which is poly erized in the respective reactor.

The polymerization for the preparation of the polypropylenes used is carried out under customary reaction conditions at temperatures from 40 to 120 ° C., in particular from 50 to 100 ° C. and pressures from 10 to 100 bar, in particular from 20 to 50 bar. Suitable polypropylenes generally have a melt flow rate (MFR), according to ISO 1133, of 0.1 to 200 g / 10 min., In particular 0.2 to 100 g / 10 min., At 230 ° C. and under a weight of 2.16 kg.

Particularly preferred polyolefins are low density polyethylene homopolymer (PE-LD) and polypropylene homopolymer.

In the process for the preparation of polyolefins, the light stabilizers are selected according to the invention from the compounds a) to d) mentioned at the outset. "Connections" should be understood as a connection class, ie as a class of individual connections.

The compounds a) are cyanoacrylic acid esters of the formula I.

With

R ¹ and R ^{11 are} hydrogen, -CC ₂₀ alkyl, C ₂ -C ₀ -alkenyl, C ₃ -C ₀ -cyclo- alkenyl, -C- ₂ alkoxy, aryl, heteroaryl, optionally substituted, X ethyl, 2nd Ethylhexyl, pentaerythrityl,

Propane-1,2,3-triyl, polyalkylene glycol residue, n integer from 0 to 3, m integer from 1 to 4.

Preferably n = 0, i.e. the aromatic systems are unsubstituted. M is preferably 1 or 4.

For m = 1, X is preferably ethyl or 2-ethylhexyl. From formula I with n = 0, m = 1 and X = ethyl, the individual compound al) results:

commercially available e.g. as Univul®3035 from BASF.

For m = 4, X is preferably pentaerythrityl, which is derived from pentaerythritol

CH ₂ ■ -. OH

HO CH ₂ - CH ₂ OH

CH ₂ OH

derives. From formula I with n = 0, m = 4 and X = pentaerythrityl the individual compound a2) results:

commercially available e.g. as Uvinul® 3030 from BASF

The individual compound a3) results from formula I with n = 0, m = 1 and X = 2-ethylhexyl:

commercially available e.g. as Univul® 3039 from BASF.

For m = 3, X is preferably propane-1, 2, 3-triyl, which is derived from glycerol

CH ₂ OH

CH ₂ OH

CH ₂ OH

derives.

Preferred polyalkylene glycol radicals X are derived from the formula

HO-R ¹ CR ¹¹ 0 "H

from, where R ¹ and R ^{11 have} the meaning already defined.

The 2-cyanoacrylic acid esters a) of the formula I are preferably obtained by reacting cyanoacetic acid esters of the general formula Ia

with n mol of a compound (Ib)

available with T = 0 or NH under the conditions of Knoevenage -r-onαensd- tion. The reaction can be carried out, for example, in aromatic solvents such as toluene or xylene (see, for example, Organikum, 19th edition, Verlag Barth Leipzig 1993, p. 476). However, polar organic solvents such as

Dimethylformamide, dimethylacetamide, N-methylpyrrolidone, trialkyl orthoformate or alcohols such as n-propanol, n-butanol, ethylene glycol, diethylene glycol, ethylene glycol monomethyl ether, cyclohexanol or similar compounds are used. If the starting compounds used already form a liquid mixture, an additional solvent can be dispensed with. The reaction temperatures are preferably between 20 and 180 ° C, particularly preferably between 40 and 150 ° C. The pressure is preferably normal atmospheric pressure. Depending on the reactivity of the compound Ib used, the use of a catalyst or a catalyst mixture is advantageous. Suitable catalysts are e.g. Ammonium aceta, piperidine and ß-alanine and their acetates.

In the case of very long reaction times, Lewis acids such as A1C1 ₃ , ZrCl ₄ , TiCl ₄ or especially ZnCl ₂ can also be used as catalysts for the reaction in the amounts customary for this.

The cyanoacetic esters Ia can, for example, by reacting cyanoacetic acid or its esters with the corresponding polyols X (0H) _n in the presence of a catalyst such as boric acid, p-toluenesulfonic acid, Na ₂ CO ₃ or K ₂ CO ₃ or tetrabutyl orthotitanate, preferably in toluene or xylene getting produced.

The compounds b) are 4,4-diarylbutadienes of the formula II

in which the diene system in the Z, Z; Z, E; E, Z or E, E configuration or a mixture thereof and in which the variables have the following meaning independently of one another:

R ¹ and R ² are hydrogen, C ₂₀ alkyl, C ₂ -Cι ₀ alkenyl, C ₃ -Cι ₀ -cycloalkyl, C ₃ -Cι ₀ cycloalkenyl, Cι-Cι ₂ -alkoxy, C ₂ o-alkoxycarbonyl, -CC ₂ -alkylamino, C ₁ -C ₁₂ -Dialkyla1rd.no, aryl, heteroaryl, optionally substituted, water-solubilizing substituents selected from the group consisting of carboxylate, sulfonate or ammonium residues;

R ^{3 is} hydrogen, COOR ⁵ , COR ⁵ , CONR ⁵ R ⁶ , CN, 0 = S (-R ⁵ ) = 0,

0 = S (-OR ⁵ ) = 0, R ⁷ 0-P (-OR ⁸ ) = 0,

Ci-Cao-Al yl, C ₂ -Cιo alkenyl, C ₃ -Cι ₀ cycloalkyl, C ₇ -Cιo bicycloalkyl, C ₃ -Cιo cycloalkenyl, C -Cιo bicyclo alkenyl, aryl, heteroaryl, optionally substituted ;

R ⁴ COOR ⁶ , COR ⁶ , CONR ⁵ R ⁶ , CN, 0 = S (-R ⁶ ) = 0, 0 = S (-0R ⁶ ) = 0,

R ⁷ 0-P (-OR ⁸ ) = 0

Cι-C ₂ -alkyl, C ₂ -Cι ₀ alkenyl, C ₃ -Cιo cycloalkyl, C ₇ -Cιo bicycloalkyl, C ₃ -Cιo cycloalkenyl, C ₇ -Cιo-bicyclo alkenyl, aryl, heteroaryl, optionally substituted;

R ⁵ to R ⁸ are hydrogen, C ₂ -alkyl, C ₂ -Cι ₀ alkenyl, C ₃ -Cι ₀ -cycloalkyl, C ₇ -Cιo bicycloalkyl, C ₃ -Cιo cycloalkenyl, C -Cιo Bicycloalkenyl, aryl, heteroaryl, optionally substituted;

n 1 to 3,

where the variables R ³ to R ⁸ , together with the carbon atoms to which they are attached, can together form a 5- or 6-ring, which may optionally be fused further,

Preferred compounds of the formula II are those in which

R ¹ and R ² independently of one another hydrogen, -CC ₂ alkyl,

C -Cs-alkoxy, -CC ₂ -alkylamino, -CC ₂ -dialkylamino, water-solubilizing substituents selected from the group consisting of carboxylate, sulfonate or ammonium radicals;

R ^{3 is} hydrogen, COOR ⁵ , COR ⁵ , CONR ⁵ R ⁶ , CN,

C ₁ -C ₂ alkyl, C ₃ -C ₆ cycloalkyl, C ₇ -C ₀ bicycloalkyl, phenyl, naphthyl, thienyl, optionally substituted;

R ⁴ COOR ⁶ , COR ⁶ , CONR ⁵ R ⁶ , CN,

C ₁ -C ₂ alkyl, C ₃ -C ₀ cycloalkyl, C ₇ -Cιo bicycloalkyl, phenyl, naphthyl, thienyl, optionally substituted; R ⁵ and R ⁶ independently of one another hydrogen, C 1 -C ₂ -Ai yl

C ₃ -C ₆ cycloalkyl, C ₇ -Cιo bicycloalkyl,

Phenyl, naphthyl, optionally substituted,

n 1 to 3

means.

As C ¹ -C ₂ -alkyl radicals, R ¹ to R ^{6 are} particularly preferably methyl, ethyl, n-propyl, 1-methylethyl, n-butyl, 1-methylpropyl, 2-methylpropyl, 1, 1-dimethylethyl, n-pentyl, Called 1-methylbutyl, 2-methylbutyl, 3-methylbutyl, 2,2-dirnethylpropyl, 2-ethylhexyl. Branched or unbranched cyclopentyl and cyclohexyl are particularly preferred as cycloalkyl radicals for R ³ to R ⁶ .

Suitable mono- or dialkylamino radicals for R ¹ and R ^{2 are} particularly preferably methyl, ethyl, n-propyl, n-butyl, 2-methylpropyl, 1, 1-dirnethylpropyl, 2-ethylhexylamino. Camphor derivatives are particularly preferred as bicycloalkyl radicals for R ³ to R ⁶ .

The substituents R ¹ and R ² can each be bound in the ortho, meta and / or para position on the aromatic. In the case of disubstituted aromatics (n = 2), R ¹ and R ^{2 can be} in the ortho / para or meta / para position. Compounds of the formula II with n - 1 in which R ^{1 is} equal to R ² and both radicals are in the para position are preferred.

Furthermore, particular preference is given to compounds of the formula II in which R ³ or R ^{4 is} not H, CN, C ₂₀ -C ₂₀ alkyl, C ₂ -C ₀ alkenyl, aryl, heteroaryl, which may be substituted if R ⁴ or R ^{3 means} COOR ⁵ or COOR ⁶ .

Compounds of the formula II and n = 1 with the following substituents are very particularly preferred:

10

The connections b) can be done according to the equation

15

25 produce by condensation, wherein R ¹ to R ^{4 have} the meaning already mentioned.

The condensation above may also be catalyzed both base- be acid- ³ ^. Suitable catalysts are:

tertiary amines, e.g. Pyridine, morpholine, triethylamine, triethanolamine; secondary amines, e.g. Piperidine, dimethylamine, diethylamine;

35 NH ₃ , NaNH ₂ , KNH ₂ , NH ₄ OAc; basic aluminum oxide, basic ion exchanger;

Na ₂ CO ₃ , K ₂ CO ₃ ; acidic catalysts such as glacial acetic acid, formic acid, propionic acid;

40 HC1, H ₂ S0 ₄ , HN0 ₃ ; acidic ion exchanger.

The amount of the catalysts is generally 0.1 to 50 mol%, preferably 0.5 to 20 mol%, of the amount of the ^ ⁵ aldehyde used. Is preferably carried out at temperatures from 20 to 150 ° C, particularly 30 to 100 ° C, particularly preferably 40 to 80 ° C. Special printing conditions are not required. lent; in general, the implementation is carried out at Atmospnarenαruc. Alcohols, such as methanol, ethanol or isopropanol; Aromatics such as toluene or xylene; Hydrocarbons, for example heptane or hexane; chlorinated hydrocarbons, such as chloroform or dichloromethane; Migol, tetrahydrofuran can be used. The reaction can also be carried out without a solvent.

It is also possible to prepare longer-chain esters starting from methyl or ethyl esters by transesterification reactions in the presence of a basic catalyst. Suitable catalysts for the transesterification are:

basic alkali and alkaline earth salts, preferably those which are neither soluble in the starting materials nor in the products and can be easily separated off after the end of the reaction, particularly preferably: sodium, potassium or calcium carbonate or sodium hydrogen carbonate;

Alkaline earth oxides, preferably calcium or magnesium oxide and basic zeolites.

The amount of the catalysts is generally 1 to 80 mol%, preferably 5 to 50 mol%, of the amount of the ester used. The amount of alcohol used must be at least equimolar to the amount of starting ester used. Amounts of 200 to 500 mol% of the alcohol are preferably used. The methanol or ethanol formed is removed by distillation. Is preferably carried out at temperatures from 50 to 250 ° C, particularly 60 to 150 ° C. Special printing conditions are not required; in general, the reaction is carried out at atmospheric pressure. Inert, higher-boiling compounds such as xylenes, but also toluene or mixtures of the alcohols used with liquid, short-chain alkanes such as hexane and heptane can be used as solvents. It is preferred to work solvent-free in the alcohol used. The transesterification can be carried out batchwise or continuously. In the continuous mode of operation, the reactants are preferably passed over a fixed bed of an insoluble base.

In the event that R ³ ≠ R ⁴ , the compounds of formula I can in principle in their various geometric isomers, ie with a Z, Z; Z, E; E, Z and / or E, E-configured service system. The all-E and / or all-Z isomers are preferred as light stabilizers, and the all-E isomers are very particularly preferred. If R ³ = R ⁴ , the C = C double bond between C-3 and C-4 (in the adjacent position to the diaryl system) in the E and / or Z configuration, preferably in the Z configuration.

Compounds c) are benzophenones of the formula III

With

Y is hydrogen, COOR ¹ or OH,

R ¹ Z OR ¹ or NR ^H A hydrogen or S0 ₃ H,

where R ^x and R ^{11 have} the meaning given in a).

Y is preferably hydrogen, or A = hydrogen, or Y and A are both hydrogen.

Preferably R ¹ = C -C ₂ o-alkyl, or R ¹¹ = -C-C ₂₀ alkyl, or R ¹ and R ^{11 are} both the same -C-C n-alkyl.

Z = OR ¹ is particularly preferred. For Z = OR ¹ , R ^{1 is} particularly preferably C ₆ -C 10 -alkyl and very particularly preferably octyl. From formula I with Y = H, A = H, Z = OR ¹ and R ¹ = octyl the individual compound cl) results:

commercially available, for example as Uvinul® 3008 from BASF.

The compounds c) are prepared, for example, as described in DE-A 214 25 93. Compounds d) are cinnamic acid esters of the formula IV

where R ¹ , R ¹¹ and n have the meaning given in a).

Preferably n = 1 and R ^x = -C 1 -C ₂ alkoxy. R ¹¹ = C ₁ -C ₂ o-alkyl is likewise preferred.

N = 1 and R ¹ = C 1C ₃ -alkoxy are particularly preferred, in particular R ¹ = OCH ₃ .

R ¹¹ = C ₆ -Co-alkyl, in particular Cs-alkyl, very particularly preferably 2-ethylhexyl, is particularly preferred.

From formula IV with n = 1, R ¹ = 0CH ₃ and R ¹¹ = 2-ethylhexyl, the individual compound dl) results:

available commercially for example as Uvinul ^® 3088 from BASF.

The compounds d) are prepared in a conventional manner by esterification of the corresponding cinnamic acid

with the corresponding alcohol R ^I3: -0H, usually with acid catalysis and removal of the water of reaction split off.

The compounds d) can also be prepared by the process described in EP-A 490 198: in a first reaction step, a dialkyl ketal of an aromatic aldehyde of the formula is used 0R ^a

with ketene of the formula CH ₂ = C = 0 in the presence of a Lewis or protonic acid as a catalyst to give a 3-arylpropionic acid derivative of the formula

around. This intermediate is reacted in a second reaction step in the presence of acid or base and the corresponding alcohol R ^{I: L} -0H with elimination of the alcohol R ^a -0H to give compound d) of the formula (IV).

The above-mentioned individual compounds a1), a2), a3), cl) and dl) are particularly preferred.

It goes without saying that more than one individual connection can be selected from each of the connection classes a) to d), and that light stabilizers from two or more of the connection classes a) to d) can also be used together. Accordingly, mixtures of different light stabilizers can also be used.

The light stabilizers are preferably added to the polyolefin in an amount of 0.005 to 10, in particular 0.01 to 5, and particularly preferably 0.05 to 2% by weight. The amount is very particularly preferably 0.1 to 1% by weight. These quantities refer to the stabilized polyolefin (polyolefin + sum of all light stabilizers a) to d)). If more than one light stabilizer is used, the quantities given relate to the sum of all light stabilizers.

In addition to the light stabilizers from the compound classes a) to d), further stabilizers can be added to the polyolefin, selected from groups a ') to x'):

a ') alkylated monophenols, b') alkylthiomethylphenols,

C) hydroquinones and alkylated hydroquinones, d ') tocopherols, e ') hydroxylated diphenyl thioethers, f) alkylidene bisphenols, g') 0-, N- and S-benzyl compounds, h ') aromatic hydroxybenzyl compounds, i') triazine compounds, j ') benzylphosphonates, k') acylaminopheno1e,

1 ') esters of β- (3,5-di-tert-butyl-4-hydroxyphenyl) propionic acid, β- (5-tert-butyl-4-hydroxy-3-methylphenyl) propionic acid , ß- (3, 5-Dicyclohexyl-4-hydroxyphenyl) propionic acid and 3, 5-di-tert. -butyl-4-hydroxyphenyl-acetic acid, m ') amides of ß- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionic acid, n') ascorbic acid and its derivatives, o ') antioxidants based on amine compounds,

P ') phosphites and phosphonites, q') 2- (2'-hydroxyphenyl) benzotriazoles, r ') sulfur-containing peroxide scavengers or sulfur-containing antioxidants s') 2-hydroxybenzophenones, t ') esters of unsubstituted and substituted benzoic acid, u') acrylates,

V) sterically hindered amines, w ') oxamides and x') 2- (2-hydroxyphenyl) -1,3, 5-triazines.

Group a ') of the alkylated monophenols includes, for example, 2,6-di-tert-butyl-4-methylphenol, 2-tert-butyl-4,6, dimethylphenol, 2,6-di-tert-butyl-4- ethylphenol, 2,6-di-tert-butyl-4-n-butylphenol, 2,6-di-tert-butyl-4-isobutylphenol, 2,6-dicyclopentyl-4-methylphenol, 2- (α-methylcyclohexyl ) -4, 6-dimethylphenol, 2, 6-dioctadecyl-4-methylphenol, 2,4, 6-tricyclohexylphenol, 2, 6-di-tert-butyl-4-methoxymethylphenol, nonylphenols, which have a linear or branched side chain, for example 2,6-di-nonyl-4-methylphenol, 2,4-dimethyl-6- (1'-methylundec-1 '- yl) -phenol, 2,4-dimethyl-6- (1'-methylheptadec-1 '-yl) phenol, 2, 4-dimethyl-6- (1' -methyltridec-1 '-yl) phenol and mixtures of these compounds.

Group b ') of the alkylthiomethylphenols include, for example, 2,4-dioctylthiomethyl-6-tert-butylphenol, 2,4-dioctylthiomethyl-6-methylphenol, 2,4-dioctylthiomethyl-6-ethylphenol and 2,6-di-dodecy1thiomethyl-1-4 - onylpheno1.

Group c ') of the hydroquinones and alkylated hydroquinones include, for example, 2,6-di-tert-butyl-4-methoxyphenol, 2,5-di-tert-butylhydroquinone, 2,5-di-tert-amylhydroquinone, 2,6- diphenyl 4-octadecyloxyphenol, 2, 6-di-tert-butylhydroquinone, 2, 5-di-tert-butyl-4-hydroxyanisole, 3, 5-di-tert-butyl-4-hydroxyanisole, 3, 5-di-tert- butyl-4-hydroxyphenyl stearate and bis (3,5-di-tert-butyl-4-hydroxyphenyl) adipate.

Group d ') of the tocopherols includes, for example, α-tocopherol, β-tocopherol, γ-tocopherol, δ-tocopherol and mixtures of these compounds, and tocopherol derivatives, such as tocopheryl acetate, succinate, nicotinate and polyoxyethylene succinate (" Tocofersolan ").

Group e ') of the hydroxylated diphenylthioethers includes, for example, 2,2'-thiobis (6-tert-butyl-4-methylphenol), 2,2'-thiobis (4-octylphenol), 4,4'-thiobis (6-tert -butyl-3-methylphenol), 4, '-Thiobis (6-tert-butyl-2-methylphenol), 4,4'-thio-bis- (3, 6-di-sec-amylphenol) and 4, 4'-bis (2,6-dimethyl-4-hydroxyphenyl) disulfide.

Group f) of the alkylidene bisphenols includes, for example, 2,2'-methylenebis (6-tert-butyl-4-methylphenol), 2,2'-methylenebis (6-tert-butyl-4-ethylphenol), 2,2 '- Methylenebis [4-methyl-6- (α-methylcyclohexyl) phenol], 2,2'-methylenebis (4-methyl-6-cyclohexylphenol), 2,2'-methylenebis (6-nonyl-4-methylphenol), 2,2'-methylenebis (4,6-di-tert-butylphenol), 2,2-ethylidene bis (4,6-di-tert-butylphenol), 2,2 'ethylidebis (6-tert-butyl-4 -isobutylphenol), 2,2 'methylenebis [6- (α-methylbenzyl) -4-nonylphenol], 2,2' methylenebis [6- (α, α-dimethylbenzyl) -4-nonylphenol], 4,4 ' -Methylene bis (2, 6-di-tert-butylphenol), 4, 4 '-Methylenbis- (6-tert-butyl-2-methylphenol), 1, 1-bis (5-tert-butyl-4-hydroxy-2 -methylphenyl) butane, 2,6-bis (3-tert-butyl-5-methyl-2-hydroxybenzyl) -4 ~ methylphenol, 1,1,3-tris (5-tert-butyl-4-hydroxy- 2-methylphenyl) butane, 1, 1-bis (5-tert-butyl-4-hydroxy-2-methylphenyl) -3-n-dodecyl mercaptobutane, ethylene glycol bis [3, 3-bis (3 '- tert-butyl-4'-hydroxyphenyl) butyrate], bis (3-tert-butyl-4-hydroxy-5-methylphenyl) dicyclopentadiene, bis [2- (3 'tert-butyl-2' - hydroxy-5 '-methylbenzyl) -6-tert-butyl-4-methylphenyl] terephthalate, 1,1-bis- (3,5-dimethyl-2-hydroxyphenyl) butane, 2,2-bis- (3,5-di- tert-butyl-4-hydroxyphenyl) propane, 2,2-bis (5-tert-butyl-4-hydroxy-2-methylphenyl) -4-n-dodecyl mercaptobutane and 1,1,5, 5-tetrakis (5th -tert-butyl-4-hydroxy-2-methylphenyl) pentane.

Group g ') of the 0-, N- and S-benzyl compounds include, for example, 3, 5, 3', 5 'tetra-tert-butyl-4, 4' -dihydroxydibenzyl ether, octadecyl-4-hydroxy-3 , 5-dimethylbenzylmercaptoacetate, tridecyl-4-hydroxy-3, 5-di-tert-butylbenzylmercaptoacetate, tris (3, 5-di-tert-butyl-4-hydroxybenzyl) amine, bis (4-tert-butyl-3- hydroxy-2, 6-dimethylbenzyl) dithioterephthalate, Bis (3,5-di-tert-butyl-4-hydroxybenzyl) sulfide and isooctyl-3,5-di-tert-butyl-hydroxybenzyl mercaptoacetate.

Group h ') of the aromatic hydroxybenzyl compounds includes, for example, 1,3,5-tris (3,5-di-tert-butyl-4-hydroxybenzyl) -2,4,6-trimethylbenzene, 1,4-bis (3,4 5-di-tert-butyl-4-hydroxy-benzyl) -2, 3, 5, 6-tetramethylbenzene and 2, 4, 6-tris (3, 5-di-tert-butyl-4-hydroxybenzyl) phenol.

Group i ') of the triazine compounds includes, for example, 2,4-bis (octylmercapto) -6- (3,5-di-tert-butyl-4-hydroxyanilino) -1,3,5-triazine, 2-0ctylmercapto-4, 6-bis (3,5-di-tert-butyl-4-hydroxyanilino) -1,3,5-triazine, 2-0ctylmercapto-4,6-bis (3,5-di-tert-butyl-4-hydroxyphenoxy ) -1,3,5-triazine, 2,4,6-tris (3,5-di-tert-butyl-4-hydroxyphenoxy) -1,2,3-triazine, 1,3,5-tris (3rd , 5-di-tert-butyl-4-hydroxybenzyl) isocyanurate, 1,3, 5-tris (4-tert-butyl-3-hydroxy-2, 6-dimethylbenzyl) isocyanurate, 2,4, 6-tris (3rd , 5-di-tert-butyl-4-hydroxyphenylethyl) -1,3,5-triazine, 1,3,5-tris (3,5-di-tert-butyl-4-hydroxyphenylpropionyl) hexahydro-1, 3,5-triazine, 1,3,5-tris (3,5-dicyclohexyl-4-hydroxybenzyl) isocyanurate and 1,3,5-tris (2-hydroxyethyl) isocyanurate.

Group j ') of the benzylphosphonates include, for example, dimethyl-2, 5-di-tert-butyl-4-hydroxybenzylphosphonate, diethyl-3, 5-di-tert-butyl-4-hydroxybenzylphosphonate, dioctadecyl-3, 5-di-tert -butyl-4-hydroxybenzylphosphonate and dioctadecyl-5-tert-butyl-4-hydroxy-3-methylbenzylphosphonate.

Group k ') of the acylaminophenols includes, for example, 4-hydroxylauroylanilide, 4-hydroxystearoylanilide and octyl-N- (3,5-di-tert-butyl-4-hydroxyphenyl) carbamate.

The esters of the propionic and acetic acid derivatives mentioned in group 1 ') are based on monohydric or polyhydric alcohols, for example methanol, ethanol, n-octanol, i-octanol, octa-decanol, 1, 6-hexanediol, 1, 9-nonanediol, Ethylene glycol, 1,2-propanediol, neopentyl glycol, thiodiethylene glycol, diethylene glycol, triethylene glycol, pentaerythritol, tris (hydroxyethyl) isocyanurate, N, N'-bis (hydroxyethyl) oxamide, 3-thiaundecanol, 3-thiapentadecanol, trimethylhexanediol, trimethylolpropanediol and 4-hydroxymethyl-l-phospha-2, 6, 7-trioxabicyclo [2.2.2] octane.

The amides of the propionic acid derivative mentioned in group m ') are based on amine derivatives, for example N, N' - bis (3,5-di-tert-butyl-4-hydroxyphenylpropionyl) hexamethylene diamine, N, '- Bis (3, 5-di-tert-butyl-4-hydroxyphenylpropionyl) trimethylene diamine and N, N 'bis (3, 5-di-tert-butyl-4-hydroxyphenylpropionyl) hydrazine.

In addition to ascorbic acid (vitamin C), group n ') also includes ascorbic acid derivatives such as, for example, ascorbyl palmitate, laurate and stearate, and ascorbyl sulfate and phosphate.

The group o ') of the antioxidants based on amine compounds include, for example, N, N' -di-isopropyl-p-phenylenediamine, N, N'-di-sec-butyl-p-phenylenediamine, N, N'-bis (1, 4-dimethylpentyl) - p-phenylenediamine, N, N'-bis (l-ethyl-3-methylpentyl) -p-phenylenediamine, N, N 'bis (1-methylheptyl) -p-phenylenediamine, N, N '-Dicyclo-hexyl-p-phenylenediamine, N, N'-diphenyl-p-phenylenediamine, N, N'-bis (2-naphthyl) -p-phenylenediamine, N-isopropyl-N' -phenyl-p-phenylene diamine, N- (1,3-dimethylbutyl) -N '-phenyl-p-phenylenediamine,

N- (1-methylheptyl) -N '-phenyl-p-phenylenediamine, N-cyclohexyl-N' - phenyl-p-phenylenediamine, 4- (p-toluenesulfamoyl) diphenylamine, N, N '-dirnethyl-N, N '-di-sec-butyl-p-phenylenediamine, diphenylamine, N-allyldiphenylamine, 4-isopropoxydiphenylamine, N-phenyl-1-naphthylamine, N- (4-tert-octylphenyl) -1-naphthylamine, N-phenyl-2- naphthylamine, octyl-substituted diphenylamine, such as, for example, p, p '-di-tert-octyldiphenylamine, 4-n-butylaminophenol, 4-butyrylaminophenol, 4-nonanoylaminophenol, 4-dodecanoylamino-phenol, 4-octadecanoylaminophenoxy, bis [ 2, 6-di-tert-butyl-4-dimethylaminomethylphenol, 2, 4-diaminodiphenylmethane, 4, 4 '-diaminodiphenylmethane, N, N, N', N '-tetramethyl-4, 4'-diaminodiphenylmethane, 1, 2-bis [(2-methylphenyl) amino] ethane, 1, 2-bis (phenylamino) propane, (o-tolyl) biguanide, bis [4- (1 ', 3' -diethylbutyl) phenyl] amine, tert -octyl-substituted N-phenyl-1-naphthylamine, a mixture of mono- and dialkylated tert-butyl / tert-octyl diphen ylamine, a mixture of mono- and dialkylated nonyldiphenylamine, a mixture of mono- and dialkylated dodecyldiphenylamine, a mixture of mono- and dialkylated isopropyl / isohexyldiphenylamine, a mixture of mono- and dialkylated tert-butyldiphenylamine, 2, 3-dihydro-3, 3-dimethyl-4H-l, 4-benzothiazine, phenothiazine, a mixture of mono- and dialkylated tert-butyl / tert-octylphenothiazine, _> a mixture of mono- and dialkylated tert-octylphenothiazine, N-allylphenothiazine, N, N, N ', N' -tetraphenyl-1, 4-diaminobut-2-ene, N, N-bis (2,2,6, 6-tetramethyl-piperidin-4-yl) hexamethylene diamine, bis (2,2,6, 6-tetramethylpiperidin-4-yl) sebacate, 2,2,6, 6-tetramethylpiperidin-4-one and 2, 2, 6, 6-tetramethylpiperidin-4-ol.

The group p ') of the phosphites and phosphonites include, for example, triphenyl phosphite, diphenylalkyl phosphite, phenyl dialkyl phosphite, tris (nonylphenyl) phosphite, trilauryl phosphite, triocadecyl phosphite, distearylpentaerythritol diphosphite, tris (2,4-di- tert-butylphenyl) phosphite, diisodecylpentaerythritol diphosphite, bis (2, 4-di-tert-butylphenyl) pentaerythritol diphosphite, bis (2, 6-di-tert-butyl-4-methylphenyl) pentaerythritol diphosphite, diisodecyloxypentaerythritol diph (diphosphite) tert-butyl-6-methylphenyl) pentaerythritol diphosphite, bis (2,4,6-tris (tert-butylphenyl)) pentaerythritol diphosphite, tristearyl sorbitol tol triphosphite, tetrakis (2,4-di-tert-butylphenyl) -4, 4'-biphenyl-diphosphonite, 6-isooctyloxy-2, 4,8, 10-tetra-tert-butyl-12H-di-benz- [d, g] -1, 3, 2-dioxaphosphocin, 6-fluoro-2 , 4,8, 10-tetra-tert-butyl-12-methyl-dibenz [d, g] -1, 3, 2-dioxaphosphocin, bis (2, 4-di-tert-butyl-6-methylphenyl) methyl phosphite and Bis (2,4-di-tert-buty1-6-methylpheny1) ethylphosphi.

Group q ') of the 2- (2' -hydroxyphenyl) benzotriazoles includes, for example, 2- (2 '-hydroxy-5' -methylphenyl) benzotriazole, 2- (3 ', 5' -di-tert-butyl-2 '-hydroxyphenyl) benzotriazole, 2- (5'-tert-butyl-2' -hydroxyphenyl) benzotriazole, 2- (2 '-hydroxy-5' - (1,1,3,3-tetramethylbutyl) phenyl) benzotriazole, 2 - (3 ', 5' -Di-tert-butyl-2 '- hydroxyphenyl) -5-chloro-benzotriazole, 2- (3' tert-butyl-2 '- hydroxy-5' -methylphenyl) -5-chloro -benzotriazole, 2- (3 '-sec-butyl- 5'-tert-butyl-2'-hydroxyphenyl) -benzotriazole, 2- (2' -Hydroxy-4 '- octyloxyphenyl) -benzotriazole, 2- (3', 5'-di-tert-amyl-2'-hydroxyphenyl) benzotriazole, 2- (3 ', 5' bis (α, cc-dimethylbenzyl) -2'-hydroxyphenyl) benzotriazole, a mixture of 2- ( 3 'tert -butyl-2' -hydroxy-5 '- (2-octyloxycarbonylethyl) phenyl) -5-chlorobenzotriazole, 2- (3' tert -butyl-5 '- [2- (2- ethylhexyloxy) carbonylethyl] - 2'-hydroxyphenyl) -5-chlorobenzotriazole, 2- (3 'tert-butyl-2' - hydroxy-5 '- (2-methoxycarbonylethyl) phenyl) -5-chloro-benzotriazole, 2- (3' tert-butyl-2 '-hydroxy-5' - (2-methoxycarbonylethyl) phenyl) benzotriazole, 2- (3 '- Tert-butyl-2'-hydroxy-5 '- (2-octyloxycarbonylethy1) phenyl) benzotriazole, 2- (3' tert-butyl-5 '- [2- (2-ethylhexyloxy) carbonylethyl] - 2'-hydroxyphenyl) benzotriazole, 2- (3 '-dodecyl-2' -hydroxy-5 '-methylphenyl) -benzotriazole and 2- (3' tert-butyl-2 '- hydroxy-5' - (2- isooctyloxycarbonylethyl) phenylbenzotriazole,

2,2 'methylene bis [4- (1,3,3-tetramethylbutyl) -6-benzotriazol-2-ylphenol]; the product of the complete esterification of 2- [3 'tert-butyl-5' - (2-methoxycarbonylethyl) -2 '-hydroxyphenyl] - 2H-benzotriazole with polyethylene glycol 300; [R-CH ₂ CH ₂ -C00 (CH ₂ ) ₃ + ₂ , with R = 3 'tert -butyl-4' hydroxy-5 '-2H-benzotriazol-2-ylphenyl.

The group r ') of the sulfur-containing peroxide scavengers or sulfur-containing antioxidants include, for example, esters of 3, 3' thiodipropionic acid, for example the lauryl, stearyl, myristyl or tridecyl esters, mercaptobenzimidazole or the zinc salt of 2-mercaptobenzimidazole, zinc dibutyldithiocarbamate, dioctadecyl disulfide and pentaerythritol tetrakis (ß-dodecylmercapto) propionate.

The group s') of the 2-hydroxybenzophenones include, for example, the 4-hydroxy, 4-methoxy, 4-0ctyloxy, 4-decyloxy, 4-dodecyloxy, 4-benzyloxy,, 2 ', 4' -Trihydroxy- and 2 '-Hydroxy-4, 4' -dimethoxy derivatives.

The group t ') of the esters of unsubstituted and substituted benzoic acid includes, for example, 4-tert-butylphenyl salicylate, phenyl salicylate, octylphenyl salicylate, dibenzoyl resorcinol, bis (4-tert-butyl benzoyl) resorcinol, benzoyl resorcinol, 2,4-di-tert-but-butyl 5-di-tert-butyl-4-hydroxybenzoate, hexadecyl-3, 5-di-tert-butyl-4-hydroxybenzoate, octadecyl-3, 5-di-tert-butyl-4-hydroxybenzoate and 2-methyl-4, 6-di-tert-butylphenyl-3, 5-di-tert-butyl-4-hydroxybenzoate.

The group u ') of the acrylates include, for example, ethyl α-cyano-β, β-diphenyl acrylate, isooctyl-α-cyano-β, β-diphenyl acrylate, methyl α-methoxycarbonylcinnamate, methyl α-cyano-β-methyl-p -methoxy-cinnamate, butyl-α-cyano-β-methyl-p-methoxy-cinnamate and methyl-α-methoxycarbonyl-p-methoxycinnamate.

Group v ') of the sterically hindered amines includes, for example, bis (2, 2, 6, 6-tetramethylpiperidin-4-yl) sebacate, bis (2, 2,6, 6-tetramethylpiperidin-4-yl) succinate, bis (1,2,2,6, 6-pentamethylpiperidin-4-yl) sebacate, bis (l-octyloxy-2, 2, 6, 6-tetramethylpiperidin-4-yl) sebacate, bis (1,2 , 2,6, 6-pentamethylpiperidin-4-yl) -n-butyl-3, 5-di-tert-butyl-4-hydroxybenzylmalonate, the condensation product from 1- (2-hydroxyethyl) -2,2,6 , 6-tetramethyl-4-hydroxypiperidine and succinic acid, the condensation product of N, N'-bis (2,2,6, 6-tetramethylpiperidin-4-yl) hexamethylenediamine and 4-tert-octylamino-2, 6-dichloro -l, 3,5-triazine, tris (2,2,6,6-tetra-methylpiperidin-4-yl) nitrilotriacetate, tetrakis (2,2,6,6-tetra-methylpiperidin-4-yl) -1, 2,3,4-butane-tetracarboxylate, 1,1 '- (1,2-ethylene) -bis (3,3,5,5-tetramethylpiperazinone), 4-benzoyl-2, 2,6,6-tetramethylpiperidine, 4-stearyloxy-2, 2,6, 6-tetramethylpiperidine, bis (1,2,2,6, 6-pentamethylpiperidin-4-yl) -2-n -butyl-2- (2-hydroxy-3, 5-di-tert-butylbenzyl) malonate, 3-n-octyl-7, 7,9, 9-tetramethyl-1,3, 8-triazaspiro [4.5] decan 2,4-dione, bis (l-octyloxy-2, 2,6,6-tetramethylpiperidin-4-yl) sebacate, bis (l-octyloxy-2, 2,6, 6-tetra-methylpiperidin-4-yl) succinate, the condensation product of N, N'-bis (2,2,6, 6-tetramethylpiperidin-4-yl) hexamethylenediamine and 4-morpholino-2, 6-dichloro-l, 3, 5-triazine, the condensation product 2-chloro-4, 6-bis (4-n-butylamino-2, 2, 6, 6-tetramethylpiperidin-4-yl) -1,3,5-triazine and 1, 2-bis (3-aminopropylamino) ethane , the condensation product from 2-chloro-4, 6-di- (4-n-butylamino- 1,2,2,6,6-pentamethylpiperidin-4-yl) -1,3,5-triazine and α1,2-bis- (3-aminopropylamino) ethane, 8-acetyl-3-dodecyl-7,7 9,9-tetramethyl-1, 3, 8-triazaspiro [4.5] -decan-2, 4-dione, 3-dodecyl-l- (2,2,6, 6-tetramethylpiperidin-4-yl) pyrrolidin-2, 5-dione, 3-dodecyl-1- (1,2,2,6,6-pentamethylpiperidin-4-yl) pyrrolidine-2,5-dione, a mixture of 4-hexadecyloxy and 4-stearyloxy-2 , 2, 6, 6-tetramethylpiperidine, the condensation product of N, N'-bis (2,2,6, 6-tetramethylpiperidin-4-yl) hexamethylene diamine and 4-cyclohexylamino-2, 6-dichloro-1,3 , 5-triazine, the condensation product of 1,2-bis (3-aminopropylamino) -ethane and 2,4,6-trichloro-1,3,5-triazine, 4-butylamino-2, 2,6 , 6-tetramethylpiperidine, N- (2, 2, 6, 6-tetramethylpiperidin-4-yl) -n-dodecylsuccinimide, N- (1, 2, 2, 6, 6-pentamethylpiperidin-4-yl) -n-dodecylsuccinimide , 2-Undecyl-7, 7,9, 9-tetramethyl-l-oxa-3, 8-diaza-4-oxo-spiro [4.5] - decane, the condensation product from 7, 7, 9, 9-tetramethyl-2 -cyclo - undecyl-l-oxa-3, 8-diaza-4-oxospiro- [4.5] decane and epichlorohydrin, the condensation products of 4-amino-2,2, 6, 6-tetramethyl-piperidine with tetramethylolacetylene diureas and poly (meth-oxypropyl -3-oxy) - [4- (2,2, 6, 6-tetramethyl) piperidinyl] siloxane.

The group w ') of the oxamides include, for example, 4,4'-dioctyl-oxyoxanilide, 2,2'-diethoxyoxanilide, 2,2'-dioctyloxy-5, 5'-di-tert-butoxanilide, 2,2'-didodecyloxy- 5, 5'-di-tert-butoxanilide, 2-ethoxy-2 '-ethyloxanilide, N, N'-bis (3-dimethylaminopropyl) oxa id, 2-ethoxy-5-tert-butyl-2' -ethoxanilide and its Mix with

2-ethoxy-2'-ethyl-5, 4'-di-tert-butoxanilide and mixtures of ortho-, para-methoxy-disubstituted oxanilides and mixtures of ortho- and para-ethoxy disubstituted oxanilides.

The group x ') of 2- (2-hydroxyphenyl) -1, 3, 5-triazines includes, for example, 2,4,6-tris (2-hydroxy-4-octyloxyphenyl) -1,3, 5-triazine, 2- (2-Hydroxy-4-octyloxyphenyl) -4,6-bis (2,4-dimethylphenyl) -1,3,5-triazine, 2- (2,4-dihydroxyphenyl) -4,6-bis (2,4-dimethylphenyl) -1,3,5-triazine, 2,4-bis (2-hydroxy-4-propyloxyphenyl) -6- (2,4-dimethylphenyl) -1,3,5-triazine , 2- (2-hydroxy-4-octyloxyphenyl) -4, 6-bis (4-methylphenyl) -1,3, 5-triazine, 2- (2-hydroxy-4-dodecyloxyphenyl) -4, 6- bis (2,4-dimethylphenyl) -1,3,5-triazine, 2- (2-hydroxy-4-tridecyloxyphenyl) -4,6-bis (2,4-dimethylphenyl) -1,3,5-triazine, 2- [2-Hydroxy-4- (2-hydroxy-3-butyloxypropoxy) phenyl] -4,6-bis (2,4-dimethyl) -1,3,5-triazine, 2- [2- Hydroxy-4- (2-hydroxy-3-octyloxypropoxy) phenyl] -4,6-bis (2,4-dimethyl) -1,3,5-triazine, 2- [4- (dodecyloxy / tridecyloxy-2 -hydroxypropoxy) -2-hydroxy-phenyl] -4,6-bis (2,4-dimethylphenyl) -1,3,5-triazine, 2- [2-hydroxy-4- (2-hydroxy-3-dodecy loxypropoxy) phenyl] -4, 6-bis- (2,4-dimethylphenyl) -1,3,5-triazine, 2- (2-hydroxy-4-hexyloxy phenyl) -4,6-diphenyl-l , 3,5-triazine, 2- (2-hydroxy-4-methoxyphenyl) -4,6-diphenyl-1,3,5-triazine, 2,4,6-tris [2-hydroxy-4- (3-butoxy-2-hydroxy-propoxy) phenyl] -1,3,5-triazine and

2- (2-hydroxyphenyl) -4- (4-methoxyphenyl) -6-phenyl-1,3,5-triazine.

The further stabilizers mentioned from groups a ') to x') are used in customary amounts, in particular in quantities of 0.001 to 1% by weight, based on that with the light stabilizers a) to d) and the further stabilizers a ') to x ') stabilized polyolefin.

In the process according to the invention, the light stabilizers and, if present, the further stabilizers are added to the polyolefin. The addition takes place in the usual way. So you can add the light stabilizers and possibly the other stabilizers to the starting monomer (olefin monomers) and polymerize the mixture of monomers and stabilizers. The stabilizers can also be added during the polymerization of the olefin monomers. A prerequisite for addition before or during the polymerization is that the stabilizers are stable under the polymerization conditions, that is to say they do not decompose, or decompose only slightly.

The light stabilizers a) to d) and, if present, the further stabilizers a ') to x'), are preferably added to the finished polyolefin. This is done in the usual way according to mixing methods known per se, for example with melting at temperatures of 150 to 300 ° C. However, the components can also be mixed "cold" without melting and the powdery or granular mixture is only melted and homogenized during processing.

It goes without saying that the stabilizer (s) can be added together or separately from one another, all at once, in portions or continuously, over time or along a gradient. For example, part of the stabilizer can be added during the polymerization of the olefin monomers and the rest can only be added to the finished polyolefin.

Mixing devices for carrying out the process according to the invention are, for example, discontinuously operating, heated internal kneaders with or without a ram, continuously operating kneaders such as, for example, continuous internal kneaders, screw kneaders with axially oscillating screws, Banbury kneaders, furthermore extruders and roller mills, mixing roll mills with heated rollers and Calender. Mixing is preferably carried out in a conventional extruder, it being possible for the components to be mixed or introduced individually, for example completely into the extruder via a funnel, or else in portions at a later point in the extruder to give the melted or solid product in the extruder. Single or twin-screw extruders, for example, are particularly suitable for melt extrusion. A twin screw extruder is preferred.

The mixtures obtained can be pelletized or granulated, for example, or processed by generally known methods, for example by extrusion, injection molding, foaming with blowing agents, deep-drawing, blow molding or calendaring.

Moldings (including semi-finished products, foils, films and foams) of all kinds can be produced from the molding compounds, for example pipes for drinking water and waste water, fittings for drinking and waste water pipes, packaging and foils, in particular packaging for cosmetics (eg shampoo, creams, other water-containing cosmetic products) and packaging and films for food (eg fruit, vegetables, meat and other water-containing food), drinking water bottles, molded articles in the entire outdoor area such as Garden furniture, windows and fittings, lamp housings, automotive exterior parts. The molded articles are the subject of the invention. They are characterized by a significantly lower yellowing when exposed to water.

It has surprisingly been found that polyolefins which are stabilized against visible and ultraviolet light and which contain at least one of the compounds a) to d) as light stabilizers as defined at the outset are very resistant to yellowing when exposed to water. These polyolefins are also the subject of the invention. In particular, these stabilized polyolefins are more resistant to yellowing in the presence of water than the stabilized polyolefins of the prior art.

Particularly well when exposed to water, yellowing-resistant stabilized polyolefins contain at least one of the compounds al), a2), a3), cl) and dl) as light stabilizers. These polyolefins are also the subject of the invention.

Another object of the invention is a method for reducing the yellowing of polyolefins stabilized against visible and ultraviolet light, which are exposed to the action of water, characterized in that the used Light stabilizers are selected from the described compounds a) to d), in particular selected from the described compounds a1), a2), a3), cl) and dl).

The invention finally relates to the use of light stabilizers, selected from the compounds a) to d) as described above, in particular selected from the compounds al), a2), a3), cl) and dl) as described above, in polyolefins which are exposed to water.

Examples:

The following were used as polyolefins:

PE: Low density polyethylene homopolymer (PE-LD), density 0.919 g / cm ³ , melt flow rate MFR (melt flow rate) 0.25 g / 10 min determined according to ISO 1133 at 190 ° C and 2.16 kg load. The product Lupolen® 1840 D from Basell was used.

PP: polypropylene homopolymer, melt flow rate MFR 23 g / 10 min determined according to ISO 1133 at 230 ° C and 2.16 kg load. The Novolen® 1100 RC product from Basell was used.

The following were used as light stabilizers:

al: cyanoacrylic acid ester of the formula

The product Uvinul 3035 from BASF was used

a2: Cyanoacrylic acid ester of the formula

The product Uvinul® 3030 from BASF was used

a3: Cyanoacrylic acid ester of the formula

Uvinul® 3039 from BASF was used

cl: benzophenone of the formula

0

It was the product Uvinul ^® 3008 from BASF used

dl: cinnamic acid ester of the formula

C ₂ H ₅

H ₃ CO CH C00 CH ₂ CH C ₄ H ₉ (dl]

It was the product Uvinul ^® 3088 from BASF used

VI: Benzotriazole of the formula

HO C (CH ₃ ) ₂

for comparison. The Tinuvin® 234 product from Ciba was used.

V2: Benzotriazole of the formula

for comparison. The Tinuvin 326 product from Ciba was used.

Production of the blends and test specimens:

The polyolefin was cold premixed with the light stabilizer. The type and amount of stabilizer in the polyolefin can be found in Tables 1 and 2. This mixture was then melted and homogenized in a twin-screw extruder bursting peat ZE 25. The melt temperature was 200 ° C for polyethylene and 220 ° C for polypropylene. The melt was discharged and granulated. Test specimens of 60 x 45 x 2 mm were produced from the granules in an Aarburg 220 M injection molding machine at a melt temperature of 200 ° C and a mold surface temperature of 220 ° C.

Carrying out the measurements:

The extent of the yellowing was determined on the basis of the yellowness index (Yellowness Index Yl). The Yl of all test specimens was first determined before being stored in water. The test specimens were then stored for 100 hours at 25 ° C. in daylight in deionized water or in drinking water. The Yl after storage in water was determined.

The Yl was determined according to DIN 6167 and DIN 5033 with standard light D65 and 10 ° normal observer.

A zero Yl means that the specimen is pure white. Negative Yl values mean that the test specimen is bluish (the more negative Yl, the bluer), which is perceived by the human eye as particularly intense white. Positive YI values mean that the test specimen is yellowish (the more positive Yl, the more yellow). The more negative the Yl, the whiter the specimen appears to the viewer, the more positive the Yl, the more yellow it appears to him. Tables 1 and 2 summarize the composition of the molding compositions and the measured values. The concentration data refer to the stabilized polyolefin (polyolefin + light stabilizer). Demineralized water means fully demineralized water, V means for comparison, nb means not determined.

Table 1: stabilized polyethylene

Table 2: stabilized polypropylene

For polyethylene (Examples IV to 15V) and polypropylene (Examples 16V to 29V), the tables show that the process according to the invention provides stabilized polyolefins which yellow considerably less when exposed to water than the polyolefins stabilized according to the prior art.

First, the intrinsic color of the polyolefins according to the invention before storage in water is significantly less than the intrinsic color of the polyolefins of the prior art: at 0.25% by weight stabilizer concentration in polyethylene, the Yl before water storage (demineralized water) is in the range for the polymer according to the invention from 0 to -3 (Examples 2 to 6), in the polymer not according to the invention in the range from +3.5 to +5 (7V and 8V). At 0.5% by weight stabilizer concentration in polyethylene, the Yl in the polymer according to the invention is in the range from 0 to -3 (9 to 13), in the non-inventive polymer in the range +3.6 to +7 (14V and 15V).

At 0.25% by weight stabilizer concentration in polypropylene, the Yl before water storage in the polymer according to the invention is in the range from +1 to +8.5 (17 to 21), in the polymer not according to the invention in the range from +13.8 to +15 ( 22V and 23V). At 0.5% by weight stabilizer concentration in polypropylene, the Yl in the polymer according to the invention is in the range from +1 to +8 (24 to 27), in the polymer not according to the invention in the range from +12 to +14 (28V and 29V).

The inherent color of the molding compositions according to the invention is accordingly whiter than the inherent color of the molding compositions not according to the invention. Secondly, yellowing when exposed to water is not detectable or only weakly in the polyolefins according to the invention: after 100 hours of storage in water, the Yl of the molding compositions according to the invention changes

for polyethylene by about 1 to 3 YI units, in most examples according to the invention even by less than 1 YI unit,

- With polypropylene by about 0 to 2 YI units, in most examples according to the invention even by less than 1 YI unit.

In contrast, 100 hours of storage in demineralized water change the Yl in the molding compositions not according to the invention

for polyethylene by about 10 YI units (Examples 8V and 15V) or even by about 40 YI units (Examples 7V and 40V) in the positive direction, i.e. more yellowing,

for polypropylene by about 4 to 6 YI units (examples 22V, 23V, 28V and 29V) in the positive direction, i.e. more yellowing.

The molding compositions according to the invention accordingly do not yellow or only yellow slightly under the action of water, whereas the molding compositions not according to the invention yellow strongly.

The superiority of the polyolefins stabilized according to the invention is evident both in deionized water (demineralized water) and in ion-containing water (drinking water), and is therefore independent of the type of water.

Claims

claims

1. A process for the preparation of polyolefins which are exposed to water and which are stabilized against visible and ultraviolet light, in which light stabilizers are added to the polyolefin,

characterized in that the light stabilizers are selected from the following compounds a) to d)

a) Cyanoacrylic acid esters of the formula I.

With

R ¹ and R ¹¹ are hydrogen, C ₂ -alkyl, C ₂ -Cι ₀ "Al enyl,

C ₃ -Cιo-cycloalkenyl, Cι-Ci ₂ alkoxy, aryl, heteroaryl, optionally substituted,

X ethyl, 2-ethylhexyl, pentaerythrityl,

Propane-1,2,3-triyl, polyalkylene glycol residue, n integer from 0 to 3, m integer from 1 to 4,

b) 4, 4-diarylbutadienes of the formula II

in which the diene system in the Z, Z; Z, E; E, Z or E, E configuration or a mixture thereof and in which the variables have the following meaning independently of one another:

R ¹ and R ^{2 are} hydrogen, -C-C o-alkyl, C ₂ -Cι ₀ -alkenyl, C ₃ -Cιo-cycloalkyl, C ₃ -Cιo-cycloalkenyl, Cι-Ci ₂ -alkoxy, Cι-C ₂₀ ~ alkoxycarbonyl ' C 1 -C ₂ alkylamino, C 1 -C ₂ -dialkylamino, aryl, heteroaryl, optionally substituted, water-solubilizing substituents selected from the group consisting of carboxylate, sulfonate or ammonium radicals;

R ^{3 is} hydrogen, COOR ⁵ , COR ⁵ , CONR ⁵ R ⁶ , CN,

0 = S (-R ⁵ ) = 0, 0 = S (-OR ⁵ ) = 0, R ⁷ 0-P (-OR ⁸ ) = 0, -C-C ₂₀ alkyl, C ₂ -Cι ₀ -alkenyl, C ₃ -Cι ₀ -Cycloal- alkyl, C ₇ -Cιo bicycloalkyl, C ₃ -Cιo-cycloalkenes nyl, C ₇ -Cιo bicycloalkenyl, aryl, heteroaryl, optionally substituted;

R ⁴ COOR ⁶ , COR ⁶ , CONR ⁵ R ⁶ , CN, 0 = S (-R ⁶ ) = 0,

0 = S (-0R ⁶ ) = 0, R ⁷ 0-P (-0R ⁸ ) = 0

-C-C o-alkyl, C ₂ -Cι ₀ -alkenyl, C ₃ -Cι ₀ -cycloalkyl, C ₇ -Cιo-bicycloalkyl, C ₃ -Cιo-cycloalkenyl, C ₇ -Cιo-bicycloalkenyl, aryl, Heteroaryl, optionally substituted;

R ⁵ to R ⁸ are hydrogen, C ₂ -alkyl, C ₂ -Cι ₀ alkenyl, C ₃ -Cι ₀ cycloalkyl, C ₇ -Cι ₀ bicycloalkyl,

C ₃ -Cιo-cycloalkenyl, C ₇ -Cιo-bicycloalkenyl, aryl, heteroaryl, optionally substituted;

n 1 to 3,

where the variables R ³ to R ⁸ together, in each case together with the carbon atoms to which they are bonded, can together form a 5- or 6-ring, which can optionally be fused further,

Benzophenones of the formula III

With

Y is hydrogen, COOR ¹ or OH,

R ⁱ Z OR ¹ or N

\ TT R ¹¹

A is hydrogen or S0 ₃ H,

wherein R ¹ and R ^{11 have} the meaning given in a), and

d) cinnamic acid esters of the formula IV

(CH = CH COOR ^H (IV)

where R ¹ , R ¹¹ and n have the meaning given in a).

2. The method according to claim 1, characterized in that the polyolefins are selected from homo- and copolymers of ethylene and homo- and copolymers of propylene.

3rd Process according to claims 1 to 2, characterized in that the light stabilizers are selected from the following compounds al), a2), a3), cl) and dl)

C2H5

H ₃ CO CH COO CH CH C4H9 (dl)

Process according to Claims 1 to 3, characterized in that the light stabilizers are added in an amount of 0.05 to 2% by weight, based on the stabilized polyolefin.

Process according to claims 1 to 4, characterized in that further stabilizers selected from the groups are added to the polyolefin

a 'alkylated monophenols, b' alkylthiomethylphenols, c 'hydroquinones and alkylated hydroquinones, d' tocopherols, e 'hydroxylated diphenylthioethers, f' alkylidene bisphenols, g '0-, N- and S-benzyl compounds, h ') aromatic hydroxybenzyl compounds, i') triazine compounds, j ') benzylphosphonates, k') acylaminopheno1e, 5 1 ') esters of β- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionic acid, ß- (5-tert-butyl-4-hydroxy-3-methylphenyl) propionic acid, ß- (3, 5-dicyclohexyl-4-hydroxyphenyl) propionic acid and 3, 5-di-tert. -butyl-4-hydroxyphenyl acetic acid, 10 m ') amides of ß- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionic acid, n') ascorbic acid and its derivatives, o ') antioxidants based on amine compounds, p ') phosphates and phosphonites, 15 q') 2- (2 '-hydroxyphenyl) benzotriazoles, r') sulfur-containing peroxide scavengers or sulfur-containing antioxidants s ') 2-hydroxybenzophenones, t') esters of unsubstituted and substituted benzoic acid, u ') acrylates, v') sterically hindered amines, w ') oxamides and x') 2- (2-hydroxyphenyl) -1,3, 5-triazines.

25

Process for reducing the yellowing of polyolefins stabilized against visible and ultraviolet light, which are exposed to the action of water, characterized in that the light stabilizers used are selected

30 are from the compounds a) to d) as defined in claim 1.

A method according to claim 6, characterized in that the light stabilizers used are selected from the

35 compounds al), a2), a3), cl) and dl) as defined in claim 3.

When exposed to water, yellowing-resistant polyolefins stabilized against visible and ultraviolet light, er¬

40 available according to the method of claims 1 to 5.

9. molded articles, films and foams made from the polyolefins according to claim 8.

45 10. Use of light stabilizers selected from the

Compounds a) to d) as defined in claim 1, in polyolefins which are exposed to the action of water.