AU6123198A

AU6123198A - Plastics composition having improved weather resistance

Info

Publication number: AU6123198A
Application number: AU61231/98A
Authority: AU
Inventors: Pieter Gijsman
Original assignee: DSM NV
Current assignee: Koninklijke DSM NV
Priority date: 1997-02-12
Filing date: 1998-02-12
Publication date: 1998-09-08
Also published as: BR9807679A; CN1252081A; IL131325A0; JP2001511834A; WO1998036023A1; NL1005254C2; TR199901924T2; EP0960160A1; KR20000071031A; CA2280158A1

Description

PLASTICS COMPOSITION HAVING IMPROVED WEATHER RESISTANCE

The invention relates to a plastics composition containing a polymer and at least one hindered-amine light stabilizer. In what follows below, a hindered-amine light stabilizer will be referred to as a HALS compound.

A plastics composition containing a polymer and at least one HALS compound is disclosed in US-A- 3,904,581. Patent Specification US-A-3 , 904 , 581 describes a plastics composition which contains a polymer and a 4-aminopiperidine compound, which is a HALS compound, as a result of which the plastics composition is stabilized against degradation caused by heat and light. It is generally known that the stabilization of a plastics composition against degradation caused by heat and light, in particular against degradation caused by UV radiation, improves the weather resistance of the plastics composition, as a result of which the plastics composition becomes suitable for particular applications, for example for outdoor applications.

Although a plastics composition which contains a polymer and at least one HALS compound already has a good weather resistance, there is a need for a plastics composition which has improved weather resistance.

The object of the invention is to provide a plastics composition which has such improved weather resistance.

This object is achieved, according to the invention, in that the plastics composition according to the invention contains a polymer, at least one HALS compound and at least one bridged amine compound having at least one N-bridgehead.

Surprisingly, it has in fact been found that a plastics composition which contains a polymer, at least one HALS compound and at least one bridged amine compound having at least one N-bridgehead has a weather resistance which is appreciably better than that of the known plastics composition which does not contain the bridged amine compound having at least one N-bridgehead. It has also been found that a plastics composition which contains a polymer, at least one HALS compound and at least one bridged amine compound having at least one N-bridgehead has a weather resistance that is better than would be expected on the basis of the sum of the contributions of the HALS compound and the bridged amine compound. This is all the more surprising because it has also been found that a plastics composition which contains a polymer and only one bridged amine compound is hardly stabilized against degradation caused by heat and light. Thus, with certain choices of the components of the plastics composition according to the invention, it was found that the weather resistance of the plastics composition according to the invention could have a weather resistance which was more than double the weather resistance of the known plastics compositions.

DE 2637193 describes that compounds having the general formula

protect organic polymers against the influence of light. In Formula I, if n = 1, R is an alkyl or isoalkyl group having 1-17 C atoms, a phenylalkyl group having 1-4 C atoms in the alkyl chain, a phenyl or a naphthyl group, which may be substituted by 2 chlorine atoms, a hydroxyl group or by at most 3 alkoxy or alkyl groups having 1-4 C atoms, or represents a heterocyclic 5- or β-ring with an N or 0 atom, while, if n = 2, R stands for an alkylene group having 2 to 6 C atoms or a phenylene group. DE 2637193 describes that the aforementioned compounds (I) are also effective in the presence of the usual stabilizers such as antioxidants, UV absorbers, light stabilizers, phosphite stabilizers, metal compounds, epoxy stabilizers, polyhydric alcohols, antistatic agents, flame retardants and pigments. Sterically hindered piperidine compounds are mentioned as examples of the UV absorbers and/or light stabilizers. It is nowhere apparent from DE 2637193 that compounds having the general formula (I) would improve the effect of the usual stabilizers, let alone that there would be a synergistic effect between compounds having the general formula (I) and HALS stabilizers. Compounds having the general formula (I) are excluded from the plastics composition according to the invention.

Within the scope of this invention, a xenon test is employed as a measure of the weather resistance. The xenon test determines a plastics composition's resistance to degradation when exposed to light from a filtered (borosilicate glass) xenon lamp at a black panel temperature of 62°C having an intensity of 0.35 W-m^"2-nm^"1, at a wavelength of 340 nm and a relative humidity of 55% by volume in a wet/dry cycle of 18 minutes wet and 102 minutes dry. The degradation of the plastics composition is measured as the difference in the carbonyl absorption at 1713 cm^"1 and the absorption at 1860 cm^"1 as a function of the time for which the plastics composition is subjected to said combination of light, temperature and humidity. The weather resistance is expressed as the time for which a plastics composition is subjected to said combination of light, temperature and humidity and at which the difference between the measured carbonyl absorptions is less than a certain value to be chosen beforehand. In the xenon test employed here, this value is 0.10 for the films and 0.50 for plates.

'Hindered-amine light stabilizers' are understood to be compounds having the following general formulas :

r —

R

and combinations hereof.

Ri up to and including R₅ are herein independent substituents; examples of suitable substituents are hydrogen, ether, ester, amine, amide, alkyl, alkenyl, alkynyl, aralkyl, cycloalkyl and aryl groups, which substituents may in turn contain functional groups; examples of functional groups are alcohols, ketones, anhydrides, imines, siloxanes, ethers, carboxyl groups, aldehydes, esters, amides, imides, amines, nitriles, ethers, urethanes and any combination thereof. A hindered-amine light stabilizer may also form part of a polymer. Preferably, the HALS compound chosen is a compound derived from a substituted piperidine compound, in particular any compound which is derived from an alkyl-substituted piperidyl, piperidinyl or piperazinone compound and substituted alkoxypiperidinyl compounds . Examples of such compounds are :

- 2,2,6, 6-tetramethyl-4-piperidone;

- 2,2,6, 6-tetramethyl-4 -piperidinol;

- bis- (1,2,2,6, 6-pentamethylpiperidyl) - (3 ' , 5 ' -di-tert- butyl-4 ' -hydroxybenzyl) butylmalonate;

- di- (2 , 2 , 6 , 6-tetramethyl-4-piperidyl) sebacate (Tinuvin^* 770) ;

- oligomer of N- (2-hydroxyethyl) -2 , 2 , 6 , 6-tetramethyl-4- piperidinol and succinic acid (Tinuvin 622); - oligomer of cyanic acid and N,N-di (2 , 2 , 6 , 6- tetramethyl-4 -piperidyl) hexamethylene diamine;

- bis- (2 , 2, 6, 6-tetramethyl-4-piperidinyl) succinate;

- bis- (l-octyloxy-2 ,2,6, 6 -tetramethyl -4 -piperidinyl) sebacate (Tinuvin^* 123); - bis- (1, 2 , 2 , 6 , 6-pentamethyl-4-piperidinyl) sebacate (Tinuvin^Φ 765) ;

- tetrakis- (2,2,6, 6 -tetramethyl-4 -piperidyl) -1,2,3,4- butane tetracarboxylate;

- N,N' -bis- (2 , 2 , 6, 6-tetramethyl-4-piperidyl) hexane- 1,6-diamine (Chimassorb* T5) ;

- N-butyl-2 ,2,6, 6 -tetramethyl-4 -piperidinamine ;

- 2,2'- [(2,2,6, 6-tetramethylpiperidinyl) imino] -bis- [ethanol] ;

- poly ( (6-morpholine-S-triazine-2, 4-diyl) (2,2,6,6- tetramethyl -4 -piperidinyl) -iminohexamethylene- (2,2,6,6- tetramethyl-4-piperidinyl) -imino) (Cyasorb UV 3346);

- 5- (2 , 2 , 6 , 6-tetramethyl-4-piperidinyl) -2-cyclo- undecyloxazole) (Hostavin N20) ; - 1, 1 ' - (1, 2-ethanediyl) -bis- (3, 3', 5, 5' -tetramethyl - piperazinone) ;

- 8-acetyl-3-dodecyl-7, 7,9, 9 -tetramethyl -1 , 3 , 8-triaza- spiro (4,5) decane-2 , 4-dione ; - polymethylpropyl-3-oxy [4 (2 , 2 , 6, 6-tetramethyl) - piperidinyl) siloxane (Uvasil 299);

- 1, 2 , 3 , 4-butanetetracarboxylic acid- 1,2,3 - tris (1,2,2,6, 6 -pentamethyl-4 -piperidinyl) -4-tridecyl ester; - copolymer of -methylstyrene-N- (2 , 2 , 6 , 6 -tetramethyl- 4 -piperidinyl ) maleimide and N-stearylmaleimide ;

- 1, 2 , 3 , 4-butanetetracarboxylic acid, polymer with beta, beta, beta ' ,beta ' -tetramethyl-2 , 4 , 8 , 10- tetraoxaspiro [5.5] undecane-3 , 9-diethanol, 1,2,2,6,6- pentamethyl-4 -piperidinyl ester (Mark LA63)

- 2,4,8, 10-tetraoxaspiro [5.5] undecane-3 , 9- diethanol, beta, beta, beta ' ,beta ' -tetramethyl- , polymer with 1, 2 , 3 , 4-butanetetracarboxylic acid, 2,2,6,6- tetramethyl-4 -piperidinyl ester (Mark^R LA68) - D-glucitol, 1 , 3 : 2 , 4-bis-O- (2 , 2 , 6 , 6-tetramethyl-4 - piperidinylidene) - (HALS 7)

- oligomer of 7-oxa-3,20- diazadispiro [5.1.11.2] heneicos^'an-21-one, 2,2,4,4- tetramethyl-20- (oxiranylmethyl) (Hostavin N30) - propanedioic acid, [ (4-methoxyphenyl) methylene] - ,bis(l,2,2,6, 6 -pentamethyl -4 -piperidinyl) ester (Sanduvor¹¹ PR 31)

- formamide, N,N' -1, 6-hexanediylbis [N- (2 , 2 , 6 , 6- tetramethyl -4 -piperidinyl (Uvinul^Φ 4050H) . - 1, 3 , 5-triazine-2 , 4 , 6-triamine, N,N -[1,2- ethanediylbis [ [ [4 , 6-bis [butyl (1,2,2,6, 6 -pentamethyl-4 ^■ iperidinyl) amino] -1,3, 5-triazine-2-yl] imino] -3,1- propanediyl] ] -bis [N' ,N"-dibutyl-N^' ,N" -bis (1,2,2,6,6- pentamethyl-4-piperidinyl) (Chimassorb 119)

- 1, 5-dioxaspiro (5,5) undecane 3 , 3 -dicarboxylic acid, bis (2 , 2 , 6 , 6-tetramethyl-4-peridinyl) ester (Cyasorb^" UV-500) - 1, 5-dioxaspiro (5,5) undecane 3 , 3 -dicarboxylic acid, bis (1, 2 , 2 , 6, 6-pentamethyl-4-peridinyl) ester (Cyasorb^R UV-516)

- N-2 , 2 , 6 , 6 -tetramethyl-4 -piperidinyl-N-amino-oxamide ;:

- 4-acryloyloxy-l, 2,2,6, 6 -pentamethyl -4 -piperidine; - 1,5,8,12-tetrakis [2 ' , 4 ' -bis (1",2",2" ,6", 6"- pentamethyl-4" -piperidinyl (butyl) amino) -1 ' , 3 ' , 5 ' - triazin-6 ' -yl] -1,5,8, 12-tetrazadodecane .

HALS PB-41 (Clariant Huningue S.A.)

Nylostab^® S-EED (Clariant Huningue S.A.) 3-dodecyl-l- (2,2,6, 6 -tetramethyl-4 -piperidyl) - pyrrolidin-2 , 5-dione

Uvasorb^® HA88

1,1'- ( 1,2 -ethane-di-yl) -bis- (3,3' ,5,5' -tetra-methyl- piperazinone) (Good-rite^® 3034) 1,1', 1"- (1,3, 5-triazine-2 , 4, 6-triyltris

( (eyelohexylimino) -2 , 1-ethanediyl) tris (3,3,5,5- tetramethylpiperazinone) ; (Good-rite^® 3150)

1,1', 1"- (1,3, 5-triazine-2,4, 6- triyltris ( (eyelohexylimino) -2, 1- ethanediyl) tris (3,3,4,5, 5-tetramethylpiperazinone)

(Good-rite^® 3159)

Preferably use is made of di- (2,2,6,6- tetra ethyl-4 -piperidyl) sebacate, (also known under the tradename of Tinuvin^R 770), oligomer of N-(2- hydroxyethyl) -2 , 2, 6, 6-tetramethyl-4-piperidinol and succinic acid (Tinuvin^® 622); bis- (l-octyloxy-2 , 2 , 6 , 6- tetramethyl -4 -piperidinyl) sebacate (Tinuvin^® 123); bis - (1,2,2,6, 6 -pentamethyl -4 -piperidinyl ) sebacate (Tinuvin^® 765); N, N' -bis- (2 , 2 , 6 , 6 -tetramethyl-4 - piperidyl) -hexane-1, 6 -diamine (Chimassorb^® T5); poly ( (6-morpholine-S-triazine-2 , 4-diyl) (2,2,6,6- tetramethyl-4 -piperidinyl) -iminohexamethylene- (2,2,6,6- tetramethyl-4-piperidinyl) -imino) (Cyasorb^® UV 3346); 5- (2,2,6, 6-tetramethyl-4-piperidinyl) -2-cyclo-undecyl- oxazol) (Hostavin^® N20) ; polymethylpropyl-3-oxy- [4(2,2,6, 6-tetramethyl) - piperidinyl) -siloxane (Uvasil^® 299) , - 1, 2 , 3 , 4-butanetetracarboxylic acid, polymer with beta, beta, beta¹ ,beta' -tetramethyl-2 , 4 , 8 , 10- tetraoxaspiro [5.5] undecane-3 , 9-diethanol, 1,2,2,6,6- pentamethyl-4 -piperidinyl ester (Mark^® LA63)

- 2,4,8, 10-tetraoxaspiro [5.5] undecane-3 , 9- diethanol, beta, beta, beta' , beta' -tetramethyl- , polymer with 1, 2 , 3 , 4-butanetetracarboxylic acid, 2,2,6,6- tetra ethyl -4 -piperidinyl ester (Mark^® LA68)

- D-glucitol, 1, 3 :2 , 4-bis-O- (2, 2 , 6, 6 -tetramethyl -4- piperidinylidene) (HALS 7) - oligomer of 7-oxa-3,20- diazadispiro [5.1.11.2] heneicosan-21-one, 2,2,4,4- tetramethyl-20- (oxiranylmethyl) (Hostavin^® N30)

- propanedioic acid, [ (4-methoxyphenyl) methylene] - ,bis(l,2,2,6, 6 -pentamethyl-4 -piperidinyl) ester (Sanduvor^® PR 31)

- formamide, N,N' -1, 6-hexanediylbis [N- (2 , 2 , 6 , 6- tetramethyl-4-piperidinyl (Uvinul^® 4050H) .

- 1, 3 , 5-triazine-2 , 4 , 6-triamine, N,N'"-[1,2- ethanediylbis [ [ [4 , 6-bis [butyl (1,2,2,6,6- pentamethyl-4-iperidinyl) amino] -1,3, 5-triazine-2- yl] imino] -3 , 1-propanediyl] ] -bis [N' ,N" -dibutyl-N^' ,N" - bis (1, 2 , 2 , 6, 6-pentamethyl-4-piperidinyl) (Chimassorb^® - 1, 5-dioxaspiro (5,5) undecane 3 , 3 -dicarboxylic acid, bis (2 , 2, 6, 6-tetramethyl-4-peridinyl) ester (Cyasorb^® UV-500)

- 1, 5-dioxaspiro (5,5) undecane 3 , 3 -dicarboxylic acid, bis (1, 2 , 2, 6, 6-pentamethyl-4-peridinyl) ester (Cyasorb^® UV516)

- mixtures of esters of 2 , 2 , 6, 6-tetramethyl-4- piperidinol and fatty acids (Cyasorb^® UV 3853); HALS PB-41 (Clariant Huningue S.A.) Nylostab^® S-EED (Clariant Huningue S.A.)

3-dodecyl-l- (2,2,6, 6 -tetramethyl -4 -piperidyl) - pyrrolidine-2 , 5-dione

Uvasorb^® HA88

1, 1' - (1, 2-ethane-di-yl) -bis- (3,3' ,5,5' -tetra-methyl- piperazinone) (Good-rite^® 3034)

1,1',1"-(1,3, 5-triazine-2, 4 , 6-triyltris ( (cyclohexylimino) -2 , 1-ethanediyl) tris (3,3,5,5- tetramethylpiperazinone) ; (Good-rite^® 3150) 1,1',1"-(1,3, 5-triazine-2 ,4,6- triyltris ( (cyclohexylimino) -2 , 1- ethanediyl) tris (3,3,4,5, 5-tetramethylpiperazinone) (Good-rite^® 3159) .

The bridged amine compound having at least one N-bridgehead that can be used within the scope of this invention is preferably a compound derived from a compound having the general formula 1 or 2 (see formula sheet) , where Mi to M₄ are bridgeheads and each bridgehead is chosen independently of one another from carbon, nitrogen, silicon or phosphorus, with the proviso that at least one bridgehead should always be a nitrogen atom and carbon and silicon may be substituted; an N-bridgehead is defined as a bridgehead which is a nitrogen atom; Di, D_m, D__, D_Q, D_p and D_q here each stand for a chain having a length of 1 to 20 atoms, the number of atoms of which the chains are made up being equal to 1, m, n, o, p and q, each number of atoms and type of atom to be chosen independently of one another, and the chains being capable of having different lengths and being capable of being made up of different types of atoms. The chains may also contain side groups, the number of atoms in the side groups not being included in the number of atoms of the chain. Suitable choices for the atoms of which the chains are made up are carbon, nitrogen, oxygen, silicon and phosphorus. Preferably the chains are made up of 1 to 3 carbon atoms .

Preferably the bridged amine compound having at least one N-bridgehead is used with a HALS compound in a ratio, relative to the amount of HALS compound, of between approximately 1:20 (m.m) and approximately 20:1 (m.m), more preferably in a ratio of between approximately 1:10 (m.m) and approximately 10:1 (m:m) , most preferably in a ratio of between approximately 1:5 (m:m) and approximately 5:1 (m:m) . Within the limits of the latter ratios the weather resistance is better than is expected on the basis of the amounts of the bridged amine compound having at least one N-bridgehead and the HALS compound present.

The amount of bridged amine compound having at least one N-bridgehead that can be used in the plastics composition may vary within a wide range, which can be easily determined by an average person skilled in the art. The range may vary depending on for example the type of polymer, the type of HALS compound, the other additives in the additives package, the weather resistance to be realized or in general the type of plastics composition, its properties and its specific application.

It is for example possible for the bridged amine compound having at least one N-bridgehead to be present in the plastics composition in an amount, relative to the amount of polymer in the plastics composition, of, preferably, between approximately 0.01% by weight and approximately 10.0% by weight, more preferably in an amount of between 0.05% by weight and 5% by weight, most preferably in an amount of between 0.1% by weight and 2.5% by weight.

Preferably the bridged amine compound having at least one N-bridgehead is chosen so that a plastics composition is obtained having a weather resistance measured with the aid of the xenon test which is higher than approximately 500 hours, more preferably higher than approximately 750 hours, and most preferably higher than approximately 1000 hours.

Suitable choices for the bridged amine compound having at least one N-bridgehead are:

- derivatives of 7-nitro-l, 3 , 5-triazadamantane and 7- amino-1,3,5-triazadamantane ,

- derivatives of 7-amino-l, 3 , 5-triazadamantane having the general structure II or III:

(ID

: III :

where R and R' are independent substituents; examples of suitable substituents are hydrogen, ether, ester, amine, amide, alkyl, alkenyl, alkynyl, aralkyl, cycloalkyl and aryl groups, which substituents may in turn contain functional groups; examples of functional groups are alcohols, ketones, anhydrides, imines, siloxanes, ethers, carboxyl groups, aldehydes, esters, amides, imides, amines, nitriles, ethers, urethanes and any combination thereof.

The substituent may moreover connect several of the I and/or II compounds to one another. - derivatives obtained in a reaction of 7-amino-l, 3 , 5- triazadamantane with compounds containing one or more functional groups. Examples of these functional groups are: aldehydes, acids, esters, amides, ketones, anhydrides and isocyanates. - triazadamantane derivatives that are bound to a polymer (preferably a polyolefin) with the aid of an imide functionality;

- polymer-bound compounds obtained by the reaction of 7-amino-l, 3 , 5-triazadamantane with a polymer (preferably a polyolefin) functionalized with maleic anhydride ; hexamethylenetetramine (HMTA) , diazabicyclo [2.2.2] octane (DABCO) or derivatives thereof . HMTA and DABCO are easy to obtain commercially or are easy to prepare using generally known processes . HMTA, for example, can easily be prepared from the cheap and easily obtainable basic raw materials ammonia and formaldehyde.

The bridged amine compound having at least one N-bridgehead is preferably used as a salt, more preferably as an ammonium salt. Preferably a carboxylic acid is chosen as the salt-forming agent. Examples of suitable carboxylic acids are aliphatic carboxylic acids, aliphatic dicarboxylic acids and aromatic carboxylic acids. Suitable choices are stearic acid, sebacic acid, cyclohexanedicarboxylic acid and benzenetricarboxylic acid. Preferably the bridged amine compound having at least one N-bridgehead is not used as a salt if the salt-forming agent contains a halogen or sulphur, for it is generally known that halogen- containing or sulphur-containing compounds can reduce the effect of the HALS stabilizer. The bridged amine compound having at least one N-bridgehead is preferably substituted with at least one substituent having a molecular weight of preferably at least 50, more preferably at least 100. Surprisingly, it has been found that, as a result of using the bridged amine compound having at least one N-bridgehead either in its salt form, or substituted with at least one substituent having a molecular weight greater than approximately 50, or in its salt form and substituted with at least one substituent having a molecular weight greater than approximately 50, a plastics composition is obtained which has still better weather resistance. The plastics composition according to the invention preferably contains a thermoplastic polymer chosen from the group of polyolefins and styrene polymers. Suitable choices are, for example: - propylene polymers, such as propylene homopolymer, ethylene-propylene random copolymer, ethylene-propylene block copolymer and mixtures hereof. Also defined as propylene polymers within the scope of this invention are mixtures containing at least 50% by weight of one of the aforementioned propylene polymers with, for example, polyethylene or ethylene-propylene-diene copolymers ;

- ethylene polymers, such as low-density polyethylene (LDPE) , high-density polyethylene (HDPE) , very-low- density polyethylene (VLDPE) , linear-low-density polyethylene (LLDPE) or ultra-high-molecular-weight polyethylene (UHMWPE) ;

- butylene polymers, such as poly (1-butylene) . Suitable choices of styrene polymers are, for example, polystyrene, high-impact-resistant polystyrene (HIPS) , styrene-acrylonitrile copolymer (SAN) , acrylonitrile- butadiene- styrene copolymer (ABS) , styrene-maleic anhydride copolymer (SMA) and styrene-maleimide copolymer (SMI) . More preferably, the polymer is a propylene polymer or an ABS, still more preferably a propylene polymer.

The bridged amine compound having at least one N-bridgehead can be introduced into the plastics composition with the aid of one of the many standard methods known to a person skilled in the art at any desired time before making a plastic article, for example a moulded part, sheet, film, fibre, coating, foam, tape, latex or powder, from the plastics composition.

According to a first method, the bridged amine compound having at least one N-bridgehead is mixed, for example in the form of a powder, solution, emulsion or suspension, with the other components of the plastics composition which are in the form of, for example, a powder or a melt.

According to a second method, the bridged amine compound having at least one N-bridgehead is first mixed with at least one HALS compound and optionally with other additives in a so-called additives package, for example in the form of a powder, solution, emulsion or suspension, and said package is then added to the plastic, for example in the form of a powder or as a melt. The plastics composition containing a polymer, at least one HALS compound and at least one bridged amine compound having at least one N-bridgehead may also contain other additives, for example antioxidants, thermal and UV stabilizers, metal deactivators, fillers, pigments, flame retardants, optical whiteners and similar additives which are used in plastics compositions.

The invention will be explained further by reference to the examples without being limited hereto.

Examples

In the examples, the following general processes were followed. Preparation of the various bridged amines

DABCO stearate:

A solution of 28.45 grams (0.1 mol) of stearic acid in ethanol was added, drop by drop, at room temperature, with stirring, to a solution of 11.2 grams (0.1 mol) of DABCO in ethanol. The mixture was evaporated with the aid of a Rotavap.

HMTA stearate:

A solution of 28.45 grams (0.1 mol) of stearic acid in ethanol was added, drop by drop, with stirring, to a solution of 14 grams (0.1 mol) of DABCO in ethanol. The mixture was evaporated with the aid of a Rotavap.

DABCO sebacate:

A solution of 20.2 grams (0.1 mol) of sebacic acid in methanol was added, drop by drop, at room temperature, with stirring, to a solution of 22.4 grams (0.2 mol) of DABCO in methanol. The mixture was evaporated with the aid of a Rotavap.

DABCO benzene tricarboxylate :

A solution of 21 grams (0.1 mol) of benzene tricarboxylic acid in absolute ethanol was added, drop by drop, at room temperature, with stirring, to a solution of 33.6 grams (0.3 mol) of DABCO in absolute ethanol. The salt was precipitated from the solution.

The mixture was evaporated with the aid of a Rotavap and dried in a vacuum drying stove . DABCO distearate:

A solution of 56.9 grams (0.2 mol) of stearic acid in ethanol was added, drop by drop, at room temperature, with stirring, to a solution of 11.2 grams (0.1 mol) of DABCO in ethanol. The mixture was evaporated with the aid of a Rotavap and dried in a vacuum drying stove .

7-Nitro-l , 3 , 5 -triazadamantane : A mixture of 56.8 ml (1.0 mol) of nitromethane and 45 ml (1.2 mol) of formic acid was added, drop by drop, to a solution of 140.2 grams (1.0 mol) of hexamethylenetetramine in 500 ml of ethanol (80%), with constant stirring and refluxing. The mixture was refluxed for 4 hours and set aside for one night. The separated crystalline product was washed a few times with water and ethanol. After recrystallization in water, the product (white needles) was dried in the vacuum drying stove. (Literature: Czechoslov. Chem. Commun Collection [vol. 40], 1975, pp. 2179-82) .

7-Amino-l, 3 , 5 -triazadamantane :

15.0 grams of 7-nitro-l, 3 , 5- triazadamantane, 100 ml of methanol and 1.5 grams of wet Raney cobalt as a catalyst were introduced into a Parr autoclave (volume 160 ml) fitted with a stirrer and baffles. The hydrogenation was carried out for an hour at maximum speed, beneath hydrogen at 80 bar pressure and 80°C. After removal of the catalyst through filtration, the methanol was removed by means of the rotavapor. The crystalline product was dried in a vacuum drying stove. 7-Dodecylideneamino-l , 3 , 5-triazadamantane :

8.4 grams of 7-amino-l, 3 , 5 -triazadamantane , 10.0 grams of dodecanal, 85 ml of methanol, 10 ml of toluene and 2.0 grams of wet Raney cobalt as a catalyst were introduced into a Parr autoclave (volume 160 ml) fitted with a stirrer and baffles. The reaction was carried out for an hour in a nitrogen atmosphere (2 bar) at maximum speed and 80°C. After removal of the catalyst through filtration, the filtrate was evaporated with the aid of a Rotavapor and dried in a vacuum drying stove.

PP-MA-7-amino-l, 3 , 5 -triazadamantane : 0.8 grams of 7 -amino-1, 3 , 5-triazadamantane in 75 ml of solvent was added, drop by drop, with constant stirring, at 160-165°C, to a solution of 10.0 grams of PP-MA (Hostaprime^,BHC5) (PP grafted with approximately 2.8% maleic anhydride) in 150 ml of inert solvent. After cooling to approx. 90°C, the product was precipitated using 100 ml of acetone. The separated product was dried in a vacuum drying stove, after which it was compressed to form a plate at 210°C. The latter was cryogenically ground to a powder.

Preparation of a plastics composition

A polymer powder (PP or ABS) was mixed with a solution containing an amount of a HALS compound. This mixture was dried in an oven (Hereaus Vacutherm) for 24 hours at a temperature of 28°C and a pressure of approximately 20 mm Hg . Then a solution of the bridged amine compound having at least one N-bridgehead was added to the plastics composition. This plastics composition was also dried in the same way as described above. Plastics compositions (blanks) in which the amount of HALS compound and/or bridged amine compound having at least one N-bridgehead in the solution was zero were also prepared using this process.

Production of PP films and plates

The PP composition was compressed to form a film using a Fontijne press (type TP200, 5 minutes pressureless preheating at 190°C, followed by the application of a pressure of 100 - 120 kNewton, followed by 10 minutes cooling at said pressure) . The thickness was checked using a Heidenhain electronic meter. On average, thicknesses of 120 - 150 μm were obtained for the films and 1 mm for the plates.

Production of ABS films and plates

The ABS composition was compressed to form a film using a Fontijne press (type TP200, 5 minutes preheating at a pressure of 50 kNewton and 210°C, followed by the application of a pressure of 100-120 kNewton, followed by 10 minutes cooling at said pressure) . The thickness was checked using a Heidenhain electronic meter. On average, thicknesses of 120 - 150 μm were obtained for the films and 1 mm for the plates.

Production of PE films

The PE compositions were produced by means of compounding at 160°C. Next, films with a thickness of 150 μm were blown at the same temperature. Determination of the weather resistance

The weather resistance of a plastics composition was determined in a weather-resistance test performed in an Atlas Material Testing Technology Weather-0 meter (type Ci65) according to the method described in the preceding description. The degradation was measured with the aid of FT-IR. The weather resistance is then expressed as the amount of time (the number of hours) for which a plastics composition is subjected to said combination of light, temperature and humidity and at which the difference between the measured carbonyl absorptions is less than 0.10 before and after ageing in the case of the films and less than 0.5 in the case of the plates. In some cases the change in colour as a result of ageing was characterized with the aid of a calorimeter according to ASTM standard 1925.

In the examples, the following abbreviations and tradenames were used: PE : polyethylene PP: polypropylene

ABS: acrylonitrile-butadiene- styrene copolymer Tinuvin 770^*: di- (2 , 2 , 6 , 6-tetramethyl-4 -piperidyl) sebacate Tinuvin^'I622 : oligomer of N- (2 -hydroxyethyl) -2 , 2 , 6 , 6- tetramethyl-4-piperidinol and succinic acid Tinuvin"' 123: bis- (l-octyloxy-2 , 2 , 6 , 6 -tetramethyl-4- piperidinyl) sebacate Chimassorb 944: oligomer of cyanic acid and N,N- di (2 , 2 , 6 , 6-tetramethyl-4-piperidyl) -hexamethylene diamine

Chimassorb^'1' 119: 1, 3 , 5-triazine-2 , 4 , 6-triamine, N,N - [1,2-ethane-diylbis [ [ [4, 6 -bis [butyl (1,2,2,6,6- pentamethyl-4-iperidinyl) amino] -1,3, 5-triazine-2- yl] imino] -3 , 1-propanediyl] ] -bis [N' ,N' '-dibutyl-N' , N' '- bis (1, 2 , 2 , 6 , 6 -pentamethyl-4 -piperidinyl)

Hostavin N30: oligomer of 7-oxa-3 , 20-diazadispiro [5.1.11.2] -heneicosan-21-one, 2,2,4, 4- tetramethyl -20-

(oxiranylmethyl )

DABCO: diazabicyclo [2.2.2] octane

HMTA: hexamethylenetetramine

DABCO stearate: monosalt of stearic acid and DABCO DABCO distearate: salt of DABCO containing two stearic acid molecules

DABCO sebacate: salt of sebacic acid (diacid) containing two DABCO molecules

DABCO benzenetricarboxylate : salt of benzenetricarboxylic acid containing three DABCO molecules

HMTA stearate: monosalt of stearic acid and DABCO

Atade : 7-amino-l, 3 , 5 -triazadamantane

Dodecylidene-atade : 7-dodecylideneamino-l, 3,5- triazadamantane.

PP-MA-atade: MA-grafted polypropylene modified with atade, synthesized according to the above specification.

Examples I -II and Comparative Experiments A-D: Weather resistance of various plastics compositions

A series of plastics compositions was prepared using the process described above. In this process, the composition of the plastics composition was varied. Di- (2 , 2 , 6 , 6-tetramethyl-4-piperidyl) sebacate (tradename: Tinuvin 770, Ciba-Geigy, Basel) was chosen as the HALS compound. PP (Stamylan^", type P83ml8, DSM, the Netherlands) was chosen as the polymer. Films were produced from the plastics compositions using the process described above. The films were subjected to a weather-resistance test and the weather resistance was determined as described above. The results are summarized in Table 1.

Table 1 : Weather resistance of various plastics compositions

Examples III-VII and Comparative Experiments E and F: Weather resistance of plastics compositions having various concentrations of HALS compound and bridged amine compound Example I was repeated, the concentrations of the HALS stabilizer chosen and the bridged amine compound having at least one N-bridgehead being varied. The results are summarized in Table 2. From this it can be concluded that a plastics composition containing amounts of 0.1% by weight to 0.5% by weight of a bridged amine compound exhibits improved weather resistance, which increases as more bridged amine compound is used. It was thus possible to more than double the weather resistance (Example F versus VII) .

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Examples IX-XII: Weather resistance of plastics compositions containing various bridged amine compounds having at least one N-bridgehead

Example I was repeated using a plastics composition containing 0.2% of a HALS (Tinuvin⁵' 770), the type of bridged amine compound having at least one N-bridgehead being varied. The results are summarized in Table 3.

H Table 3 : Weather resistance of plastics compositions containing various types of bridged U amine compounds having at least one N-bridgehead

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Example XIII and Comparative Experiment G: Weather resistance of PE films

Example I was repeated using two plastics compositions, both composed of PE (LDPE, type 2304 ANOO, DSM, the Netherlands) and 0.05% by weight of HALS compound (Tinuvin" 770), with 0 and 0.06% by weight, respectively, of DABCO added thereto. The plastics compositions were processed to form blown films 150 μm thick. The films were exposed to light in a Suntester. The weather-resistance treatment was performed in a borosilicate glass vessel according to a method described in Polym. Peg. & Stab.. 39, 225-233 (1993) . The weather resistance was determined as described above; however, in this case, a change in the carbonyl absorption of 0.05 units was employed as determining the weather resistance. The weather resistance of the film without DABCO (Comparative Experiment G) was 2700 hours and the degradation increased considerably from 2400 hours onwards; the weather resistance of the film containing DABCO was more than 3500 hours and the degradation showed a constant profile at 0.03 units.

Example XIV and Comparative Experiments H and I : Weather resistance of ABS films Example I was repeated using three plastics compositions composed of ABS (Ronfalin , type 356**, DSM, the Netherlands), ABS and 0.5% by weight of HALS compound (Tinuvin^Φ 770) and ABS, 0.5% by weight of HALS compound and 0.5% by weight of DABCO stearate, respectively. The degradation was measured as a colour change using a colorimeter and the weather resistance was determined according to ASTM standard 1925 as the amount of time (the number of hours) for which a plastics composition is subjected to said weather- resistance test and at which the measured colour change is less than 5 units. The results are summarized in Table 4.

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Table 4 : Weather resistance of ABS plastics compositions

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Examples XV - XVII and Comparative Experiment J: Weather resistance of ABS films

A series of plastics compositions was prepared using the process described above. In this process the composition of the plastics composition was varied. Di- (2 , 2 , 6 , 6-tetramethyl-4-piperidyl) sebacate (tradename: Tinuvin^* 770, Ciba-Geigy, Basel) was chosen as the HALS compound. ABS (Ronfalin", type 356**, DSM, the Netherlands) was chosen as the polymer. Plates were produced from the plastics compositions using the process described above. The degradation was measured as a change in colour using a colorimeter and the weather resistance was determined according to ASTM standard 1925 as the amount of time (the number of hours) for which a plastics composition is subjected to said weather-resistance test and at which the measured change in colour is less than 5 units. The results are summarized in Table 5.

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Table 5 : Weather resistance of ABS plastics compositions

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Examples XVIII - XXIII and Comparative Experiments K - 0: Weather resistance of plastics compositions containing various bridged amine compounds having at least one N-bridgehead

Examples III - VIII were repeated, the type of bridged amine compound having at least one N- bridgehead being varied. The results are summarized in Table 6.

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Examples XXIV - XXIX: Weather resistance of plastics compositions containing various bridged amine compounds having at least one N-bridgehead

Examples III - VIII were repeated, the concentration of 7-amino-l, , 5-triazadamantane being varied. The results are summarized in Table 7.

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Table 7 : Weather resistance of plastics compositions having various concentrations of HALS and 7-amino-l, 3 , 5-triazadamantane .

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Examples XXX - LXXXV and Comparative Experiments R - AJ: Weather resistance of various plastics compositions .

A series of plastics compositions was prepared using the process described above. In this process the composition of the plastics composition was varied. Di- (2 , 2 , 6 , 6 -tetramethyl- -piperidyl) sebacate (Tinuvin^® 770), oligomer of N- (2 -hydroxyethyl) -2 , 2 , 6 , 6- tetramethyl-4-piperidinol and succinic acid (Tinuvin^® 622), bis- (l-octyloxy-2,2, 6, 6-tetramethyl-4- piperidinyl) sebacate (Tinuvin^® 123) , oligomer of cyanic acid and N,N-di (2 , 2 , 6 , 6-tetramethyl-4-piperidyl) hexamethylene diamine (Chimassorb^® 944), 1,3,5- triazine-2 , 4, 6-triamine, N,N - [1, 2 -ethane- diylbis [ [ [4, 6 -bis [butyl (1,2,2,6, 6 -pentamethyl-4- iperidinyl) amino] -1,3, 5-triazine-2-yl] imino] -3,1- propanediyl] ] -bis [N' ,N" -dibutyl-N' ,N"-bis (1,2,2,6,6- pentamethyl-4-piperidinyl) (Chimassorb^® 119) and oligomer of 7-oxa-3 , 20-diazadispiro [5.1.11.2]- heneicosan-21-one, 2,2,4 , 4-tetramethyl-20-

(oxiranylmethyl) - (Hostavin N30) were chosen as the HALS compounds. HMTA stearate, 7-dodecylideneamino- 1, 3 , 5 -triazadamantane and PP-MA-7-amino-l, 3 , 5- triazadamantane were chosen as the bridged amines . PP (Stamylan", type P83ml8, batch VI DSM, the

Netherlands) was chosen as the polymer. Films were produced from the plastics compositions using the process described above. The films were subjected to a weather-resistance test and the weather resistance was determined as described above. The results are summarized in Tables 8 - 20. 00 00

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Table 8 : Weather resistance of plastics compositions containing various types of HALS;

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Table 9: Weather resistance of plastics compositions containing various types of bridged U 0. amines having at least one nitrogen as a bridgehead:

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Table 10: Weather resistance of plastics compositions containing HMTA stearate and

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Table 11: Weather resistance of plastics compositions containing dodecylidene-atade and various types of HALS:

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Table 12 : Weather resistance of plastics compositions containing PP-MA-atade and various υa. types of HALS:

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Table 14 : Weather resistance of plastics compositions containing various amounts of υ bridged amines having at least one nitrogen as a bridgehead (HMTA stearate and dodecylidene-atade) :

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Table 15 : Weather resistance of plastics compositions containing various amounts of bridged amines having at least one nitrogen as a bridgehead (HMTA stearate and dodecylidene-atade) and with 0.05% HALS (Tinuvin 770):

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Table 20: Weather resistance of plastics compositions containing various amounts of ft. bridged amines having at least one nitrogen as a bridgehead (HMTA stearate and dodecylidene-atade) and with 0.2% HALS (Chimassorb 944):

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Comparative Experiments AK - AR: Weather resistance of various plastics compositions

A series of plastics compositions was prepared using the process described above. In this process the composition of the plastics composition was varied using various non-HALS stabilizers. 2-hydroxy-4- n-octoxy-benzophenone (Chimassorb 81), 2- (2 ' -hydroxy- 3 ' , 5 ' -di-tert-butyl-phenyl) -5-chloro-benzotriazol (Tinuvin¹⁸ 327) and octadecyl-3- (3 , 5-di-tert-butyl-4- hydroxy-phenyl) -propionate (Irganox⁰" 1076) were chosen as the non-HALS stabilizers. DABCO stearate and HMTA stearate were chosen as the bridged amines having an N- bridgehead. PP (Stamylan^R, type P83ml8, DSM, the Netherlands) was chosen as the polymer. Films were produced from the plastics compositions using the process described above. The films were subjected to a weather-resistance test and the weather resistance was determined as described above. The results are summarized in Table 21.

Table 21: Weather resistance of plastics compositions containing various non-HALS υft. stabilizers and bridged amines having an N-bridgehead.

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Claims

C L A I M S

Plastics composition containing a polymer and at least one hindered-amine light stabilizer, characterized in that the plastics composition also contains at least one bridged amine compound having at least one N-bridgehead, not being a compound having the general formula:

where, if n = 1, R is an alkyl or isoalkyl group having 1-17 C atoms, a phenylalkyl group having 1- 4 C atoms in the alkyl chain, a phenyl or a naphthyl group, which may be substituted by 2 chlorine atoms, a hydroxyl group or by at most 3 alkoxy or alkyl groups having 1-4 C atoms, or represents a heterocyclic 5- or 6-ring with an N or 0 atom, while, if n = 2, R stands for an alkylene group having 2 to 6 C atoms or for a phenylene group.

Plastics composition containing a polymer and at least one hindered-amine light stabilizer, characterized in that the plastics composition also contains at least one bridged amine compound having at least one N-bridgehead, and the ratio of the bridged amine compound having at least one N- bridgehead and the HALS compound lies between 1:5 (m . m) and 5 : 1 (m : m) .

3. Plastics composition according to Claim 1 or Claim 2 in which the amine compound having at least one N-bridgehead is present in an amount, relative to the total amount of polymer in the plastics composition, of between 0.1 and 2.5% by weight.

4. Plastics composition according to any one of Claims 1-3, in which the hindered-amine light stabilizer di- (2,2, 6, 6-tetramethyl-4 -piperidyl) sebacate, (also known under the tradename of

Tinuvin^® 770), oligomer of N- (2 -hydroxyethyl) - 2 , 2 , 6, 6-tetramethyl-4-piperidinol and succinic acid (Tinuvin^® 622); bis- (l-octyloxy-2 , 2 , 6, 6- tetramethyl-4-piperidinyl) sebacate (Tinuvin^® 123); bis- (1,2,2, 6, 6-pentamethyl-4 -piperidinyl) sebacate (Tinuvin^® 765); N,N' -bis- (2 , 2 , 6, 6- tetramethyl-4 -piperidyl) -hexane-1, 6-diamine (Chimassorb^® T5) ; poly ( (6-morpholine-S-triazine- 2 , 4-diyl) (2,2,6, 6-tetramethyl-4-piperidinyl) - iminohexamethylene- (2,2,6, 6 -tetramethyl-4- piperidinyl) -imino) (Cyasorb^® UV 3346); 5- (2,2,6, 6 -tetramethyl-4 -piperidinyl) -2-cyclo- undecyl-oxazol) (Hostavin^® N20) ; polymethylpropyl-3-oxy- [4(2,2,6, 6-tetramethyl) - piperidinyl) siloxane (Uvasil^® 299) ,

- 1, 2, 3, 4-butanetetracarboxylic acid, polymer with beta, beta, beta' , beta¹ -tetramethyl-2 , 4, 8, 10- tetraoxaspiro [5.5] undecane-3 , 9-diethanol,

1, 2 , 2 , 6, 6 -pentamethyl-4 -piperidinyl ester (Mark LA63)

- 2,4,8, 10-tetraoxaspiro [5.5] undecane-3 , 9- diethanol , beta, beta, beta ' , beta ' -tetramethyl- , polymer with 1, 2 , 3 , 4-butanetetracarboxylic acid, 2 , 2 , 6, 6-tetramethyl-4-piperidinyl ester (Mark LA68)

- D-glucitol, 1, 3 :2 , 4-bis-O- (2, 2 , 6 , 6- tetramethyl- 4-piperidinylidene) (HALS 7) - oligomer of 7-oxa-3,20- diazadispiro [5.1.11.2] heneicosan-21-one, 2,2,4,4- tetramethyl-20- (oxiranylmethyl) - (Hostavin N30)

- propanedioic acid, [ (4-methoxyphenyl) methylene] - ,bis(l,2,2,6, 6-pentamethyl- -piperidinyl) ester (Sanduvor PR 31)

- formamide, N,N' -1, 6-hexanediylbis [N- (2 , 2 , 6 , 6- tetramethyl-4-piperidinyl (Uvinul 4050H)

- 1, 3 , 5-triazine-2 , 4, 6-triamine, N,N -[1,2- ethanediylbis [ [ [4 , 6 -bis [butyl (1,2,2,6,6- pentamethyl-4 -iperidinyl) amino] -1,3, 5-triazine-2- yl] imino] -3, 1-propanediyl] ] -bis [N' ,N' '-dibutyl- N' ,N' '-bis (1,2,2,6, 6-pentamethyl-4 -piperidinyl) (Chimassorb 119)

- 1, 5-dioxaspiro (5,5) undecane 3 , 3 -dicarboxylic acid, bis (2 , 2 , 6 , 6-tetramethyl-4-peridinyl) ester

(Cyasorb UV-500)

- 1, 5-dioxaspiro (5,5) undecane 3 , 3 -dicarboxylic acid, bis (1, 2 , 2 , 6 , 6-pentamethyl-4 -peridinyl) ester (Cyasorb^® UV516) - mixtures of esters of 2 , 2 , 6, 6-tetramethyl-4- piperidinol and fatty acids (Cyasorb^® UV 3853); HALS PB-41 (Clariant Huningue S.A.) Nylostab S-EED (Clariant Huningue S.A.) 3-dodecyl-l- (2,2,6, 6-tetramethyl-4 -piperidyl) - pyrrolidine-2 , 5-dione Uvasorb HA88

1,1' - (1,2-ethane-di-yl) -bis- (3,3' ,5,5' -tetramethyl-piperazinone) (Good-rite^® 3034) 1,1',1"-(1,3, 5-triazine-2,4, 6-triyltris ( (cyclohexylimino) -2 , 1-ethanediyl) tris (3,3,5,5- tetramethylpiperazinone) ; (Good-rite^® 3150) 1,1', 1"- (1,3, 5-triazine-2 ,4,6- triyltris ( (cyclohexylimino) -2,1- ethanediyl) tris (3,3,4,5, 5-tetramethylpiperazinone) (Good-rite^® 3159) .

5. Plastics composition according to any one of Claims 2 - 4, characterized in that the weather resistance, measured in a xenon test, is higher than 500 hours.

6. Plastics composition according to any one of Claims 1 - 5, characterized in that the bridged amine compound having at least one N-bridgehead is hexamethylenetetramine, diazabicyclo [2.2.2] octane or a derivative of either compound.

7. Plastics composition according to any one of Claims 1 - 6, characterized in that the bridged amine compound having at least one N-bridgehead is a salt.

8. Plastics composition according to Claim 7, characterized in that the salt is an ammonium salt .

9. Plastics composition according to Claim 7 or Claim 8, characterized in that the salt is a carbonate.

10. Plastics composition according to any one of Claims 1 - 9, characterized in that the bridged amine compound having at least one N-bridgehead is substituted with at least one aliphatic or aromatic substituent having a molecular weight of at least 50.

11. Plastics composition according to any one of Claims 1 - 10, characterized in that the polymer is chosen from the group comprising propylene polymers and acrylonitrile-butadiene-styrene copolymer (ABS) .

12. Use of a bridged amine compound having at least one N-bridgehead in combination with a hindered- amine light stabilizer as a stabilizer for a plastics composition having improved weather resistance.

13. Use of a bridged amine compound having at least one N-bridgehead according to Claim 12, characterized in that the bridged amine compound having at least one N-bridgehead is hexamethylenetetramine, diazabicyclo [2.2.2] octane or a derivative of either compound. 14. Articles produced from the plastics composition according to any one of Claims 1-11. 15. Plastics composition having improved weather resistance as described and explained by reference to the examples .