EP1969097A1

EP1969097A1 - Stabilized biodiesel fuel compositions

Info

Publication number: EP1969097A1
Application number: EP06830796A
Authority: EP
Inventors: Natalie R. Li; David Royston Hughes; Patrice Cusatis; David Olenski
Original assignee: Ciba Spezialitaetenchemie Holding AG; Ciba SC Holding AG
Current assignee: BASF Schweiz AG
Priority date: 2006-01-04
Filing date: 2006-12-22
Publication date: 2008-09-17
Also published as: MX2008008745A; CN101351531A; US20070151143A1; TW200745323A; WO2007077165A1; CA2646216A1; KR20080089386A; JP2009522421A; BRPI0620902A2; AU2006334370A1

Abstract

Disclosed are stabilized biodiesel fuel compositions, which compositions comprise a bio- diesel fuel, for example the methyl esters of the fatty acids of rapeseed or soy oil, and one or more additives selected from the group consisting of the 3-arylbenzofuranones and the hin- dered amine light stabilizers, and optionally, one or more hindered phenolic antioxidants.

Description

Stabilized Biodiesel Fuel Compositions

The invention is aimed at biodiesel fuel (or bio-fuel) compositions, stabilized against the deleterious effects of heat, light and oxygen by an effective amount of a stabilizer selected from the group consisting of the 3-arylbenzofuranone stabilizers and the sterically hindered amine light stabilizers, or an effective amount of a stabilizer selected from the group consisting of the 3-arylbenzofuranone stabilizers and the sterically hindered amine light stabilizers in combination with a stabilizer selected from the group consisting of the hindered phenolic antioxidants.

WO 2004055141 teaches the stabilization of fats, oils and food. The stabilizers are selected from the group consisting of the 3-arylbenzofuranones, long chain N,N-dialkylhydroxyl- amines, substituted hydroxylamines, nitrones and amine oxides.

U.S. Pat. No. 6,548,580 teaches ethylene homo- and copolymers stabilized by sterically hindered amines or by N-hydroxy or N-oxyl derivatives to produce articles for the storage and transport of biodiesel fuel. JP2004059720 discloses polyoxymethylene resin containing a hindered amine light stabilizer that is used in a part in direct contact with a bio-diesel fuel.

EP 1 170296 teaches a process for the preparation for 3-aryl-benzofuranones. Fuel additives are disclosed therein.

EP 1 486 555, EP1 484 387 and EP1 484 388 disclose a low corrosive fuel composition for use in a blue flame burner or an optimized yellow flame burner of a boiler.

Biodiesel fuel is of increasing importance as a renewable fuel source. It may for example be employed as a fuel itself, or may be used in combination with diesel fuel.

Disclosed are biodiesel fuel compositions stabilized against the deleterious effects of heat, light and oxygen, which compositions comprise A biodiesel fuel and

An effective stabilizing amount of one or more additives selected from the group consisting of the 3-arylbenzofuranone stabilizers and the hindered amine light stabilizers and

Optionally, one or more additives selected from the group consisting of the hindered phenolic antioxidants. Also disclosed is a process for the stabilization of a biodiesel fuel against the deleterious effects of heat, light and oxygen, which process comprises incorporating into a biodiesel fuel an effective stabilizing amount of one or more additives selected from the group consisting of the 3-arylbenzofuranone stabilizers and the hindered amine light stabilizers and optionally, one or more additives selected from the group consisting of the hindered phenolic antioxidants.

Biodiesel fuels are a renewable resource and are of increasing importance. Biodiesel fuels comprise lower alkyl fatty acid esters, prepared for example by transesterify- ing triglycerides with lower alcohols, e.g. methanol or ethanol. A typical biodiesel fuel is the fatty acid methyl ester of rapeseed oil or of soy oil. Sources for biodiesel fuel include vegetable and animal sources. Recycled cooking oil may be a source of biodiesel fuel.

Biodiesel fuel and its preparation is disclosed, for example, in U.S. Pat. Nos. 5,578,090, 5,713,965, 5,891,203, 6,015,440, 6, 174,501 and 6,398, 707.

Biodiesel fuel of the invention for example comprises lower alkyl esters of a mixture of saturated and unsaturated straight chain fatty acids of from 12 to 22 C-atoms, derived from vegetable or oleaginous seeds. The term "lower alkyl ester" means CrC₅-esters, in particular methyl and ethyl esters. The mixture of methyl esters of the saturated, monounsaturated and polyunsaturated Ci₆-C₂₂-fatty acids are what is known as "biodiesel" or "rapeseed methyl ester".

Biodiesel fuel according to the invention is 100% lower alkyl fatty acid ester, or is a combination of a lower alkyl fatty acid ester with diesel fuel. The biodiesel fuel is for example between about 5 and about 95% by weight fatty acid ester and between about 95 and about 5% by weight diesel fuel. For example, the biodiesel fuel is between about 10 and about 90% by weight fatty acid ester and between about 90 and about 10% by weight diesel fuel. For instance, the biodiesel fuel is between about 25 and about 75% by weight fatty acid ester and between about 75 and about 25% by weight diesel fuel.

The 3-arylbenzofuranones antioxidants of the invention are for example those disclosed in U.S. patent Nos. 4,325,863; U.S. 4,388,244; U.S. 5, 175,312; U.S. 5,252,643; U.S.

5,216,052; U.S. 5,369, 159; U.S. 5,488, 117; U.S. 5,356,966; U.S. 5,367,008; U.S. 5,428, 162; U.S. 5,428, 177; and U.S. 5,516,920.

Particularly suitable 3-arylbenzofuranones in the invention are compounds of the formula I

in which, if n is 1 ,

Ri is naphthyl, phenanthryl, anthryl, 5,6,7,8-tetrahydro-2-naphthyl, 5,6,7,8-tetrahydro-1- naphthyl, thienyl, benzo[b]thienyl, naphtho[2,3-b]thienyl, thianthrenyl, dibenzofuryl, chrom- enyl, xanthenyl, phenoxathiinyl, pyrrolyl, imidazolyl, pyrazolyl, pyrazinyl, pyrimidinyl, pyridaz- inyl, indolizinyl, isoindolyl, indolyl, indazolyl, purinyl, quinolizinyl, isoquinolyl, quinolyl, phtha- lazinyl, naphthyridinyl, quinoxalinyl, quinazolinyl, cinnolinyl, pteridinyl, carbazolyl, β-car- bolinyl, phenanthridinyl, acridinyl, perimidinyl, phenanthrolinyl, phenazinyl, isothiazolyl, phe- nothiazinyl, isoxazolyl, furazanyl, biphenyl, terphenyl, fluorenyl or phenoxazinyl, or any of these carbocyclic or heterocyclic groups substituted by CrC₄alkyl-, Ci-C₄alkoxy-, C₁- C₄alkylthio-, hydroxyl-, halo-, amino-, Ci-C₄alkylamino-, phenylamino- or di(Ci-C₄alkyl)amino; or R₁ is a radical of the formula Il

and if n is 2,

R₁ is unsubstituted or CrC₄alkyl- or hydroxy-substituted phenylene or naphthylene; or is

R₂, R3, R₄ and R₅ independently of one another are hydrogen, chlorine, hydroxyl, CrC₂5alkyl, Cy-Cgphenylalkyl, unsubstituted or CrC₄alkyl-substituted phenyl; unsubstituted or CrC₄alkyl- substituted C₅-C₈cycloalkyl; CrC₁₈alkoxy, CrC₁₈alkylthio, CrC₄alkylamino, di(CrC₄alkyl)- amino, CrCasalkanoyloxy, CrC₂5alkanoylamino, C3-C₂5alkenoyloxy, C3-C₂salkanoyloxy which is interrupted by oxygen, sulphur or N — R₁₄ ; C₆-C₉cycloalkylcarbonyloxy, benzoyloxy or - A -

Ci-Ci₂alkyl-substituted benzoyloxy; or, in the alternative, if the radicals R₂ and R₃ or the radicals R₃ and R₄ or the radicals R₄ and R₅, together with the C-atoms to which they are attached, form a benzo ring, R₄ is additionally -(CH₂)_p-CORi₅ or -(CH₂)_qOH or, if R₃, R₅ and R₆ are hydrogen, R₄ is additionally a radical of the formula III

in which R₁ is defined as indicated above for n = 1 , R₆ is hydrogen or a radical of the formula IV

where R₄ is other than a radical of the formula III and R₁ is defined as indicated above for n = 1 ,

R₇, R₈, Rg, R₁O and R₁₁ independently of one another are hydrogen, halogen, hydroxyl, CrC₂₅alkyl, C₂-C₂₅alkyl interrupted by oxygen, sulphur or N — R₁₄ ; CrC₂₅alkoxy,

C₂-C₂₅alkoxy interrupted by oxygen, sulphur or N — R₁₄ ; CrC₂₅alkylthio, C₃-C₂₅alkenyl,

C₃-C₂₅alkenyloxy, C₃-C₂₅alkynyl, C₃-C₂₅alkynyloxy, C₇-C₉phenylalkyl, C₇-C₉phenylalkoxy, un- substituted or CrC₄alkyl-substituted phenyl; unsubstituted or CrC₄alkyl-substituted phenoxy; unsubstituted or CrC₄alkyl-substituted Cs-Cβcycloalkyl; unsubstituted or CrC₄alkyl-substi- tuted C₅-C₈cycloalkoxy; CrC₄alkylamino, di(CrC₄alkyl)amino, CrC₂₅alkanoyl, C₃-C₂₅alkanoyl interrupted by oxygen, sulphur or N — R₁₄ ; C-ι-C₂₅alkanoyloxy, C₃-C₂₅alkanoyloxy inter- rupted by oxygen, sulphur or N — R₁₄ ; Ci-C₂5alkanoylamino, C₃-C₂5alkenoyl, C₃-

C₂5alkenoyl interrupted by oxygen, sulphur or N — R₁₄ ; C₃-C₂5alkenoyloxy, C₃-

C₂₅alkenoyloxy interrupted by oxygen, sulphur or N — R₁₄ ; C6-Cgcycloalkylcarbonyl, Ce-

Cgcycloalkylcarbonyloxy, benzoyl or Ci-Ci₂alkyl-substituted benzoyl; benzoyloxy or d- Ci₂alkyl-substituted benzoyloxy; — O — C — C-R₁₅ or — o — C — C — 0-R₂₃ , or in

R₁₉ H R₂₂ the alternative, in formula II, the radicals R₇ and R₈ or the radicals R₈ and Rn, together with the C-atoms to which they are attached, form a benzene ring,

Ri₂ and Ri₃ independently of one another are unsubstituted or Ci-C₄alkyl-substituted phenylene or naphthylene, Ri₄ is hydrogen or Ci-C₈alkyl,

r i / ^R^

Ri5 is hydroxyl, —_Q ^' ^ MH , C_rCi₈alkoxy or — N_χ

^R25

Ri₆ and Ri₇ independently of one another are hydrogen, CF₃, Ci-Ci₂alkyl or phenyl, or Ri₆ and Ri₇, together with the C atom to which they are attached, form a C₅-C₈cycloalkylidene ring which is unsubstituted or substituted by 1-3 CrC₄alkyl; Ri₈ and Ri₉ independently of one another are hydrogen, CrC₄alkyl or phenyl, R₂₀ is hydrogen or CrC₄alkyl,

R₂i is hydrogen, unsubstituted or CrC₄alkyl-substituted phenyl; CrC₂₅alkyl, C₂-C₂₅alkyl inter¬

rupted by oxygen, sulphur or N — R₁₄ ; C₇-Cgphenylalkyl which is unsubstituted or

substituted on the phenyl radical by 1-3 CrC₄alkyl; C₇-C₂₅phenylalkyl which is unsubstituted or substituted on the phenyl radical by 1-3 CrC₄alkyl and interrupted by oxygen, sulphur or

N — R₁₄ , or, in the alternative, the radicals R₂₀ and R₂i, together with the C-atoms to which they are attached, form a C₅-Ci₂cycloalkylene ring which is unsubstituted or substituted by 1-3 Ci-C₄alkyl;

R₂₂ is hydrogen or Ci-C₄alkyl,

R₂3 is hydrogen, d-C₂5alkanoyl, C₃-C₂5alkenoyl, C₃-C₂5alkanoyl interrupted by oxygen, sul¬

phur or N — R₁₄ ; C₂-C₂5alkanoyl substituted by a di(CrC₆alkyl)phosphonate group;

C₆-C₉cycloalkylcarbonyl, thienoyl, furoyl, benzoyl or Ci-Ci₂alkyl-substituted benzoyl;

R₂₄ and R₂₅ independently of one another are hydrogen or CrCi₈alkyl,

R₂₆ is hydrogen or CrC₈alkyl,

R₂₇ is a direct bond, CrCi₈alkylene, C₂-Ci₈alkylene interrupted by oxygen, sulphur or

\

N — R₁₄ ; C₂-Ci₈alkenylene, C₂-C₂₀alkylidene, C₇-C₂₀phenylalkylidene,

C₅-C₈cycloalkylene, C₇-C₈bicycloalkylene, unsubstituted or Ci-C₄alkyl-substituted phenylene,

^X24

- 1 r+ R₂₈ is hydroxyl, | ₀ ^~ — M | , CrCi₈alkoxy or — N \

R ^■25 O R₂₉ is oxygen, -NH- or ^X _N _Q__NH _ _R ,

/ ³⁰

R₃₀ is CrCi₈alkyl or phenyl, R₃₁ is hydrogen or CrCi₈alkyl, M is an r-valent metal cation, X is a direct bond, oxygen, sulphur or -NR₃₁-, n is 1 or 2, p is O, 1 or 2, q is 1 , 2, 3, 4, 5 or 6, r is 1 , 2 or 3, and s is 0, 1 or 2.

Naphthyl, phenanthryl, anthryl, 5,6,7,8-tetrahydro-2-naphthyl, 5,6,7,8-tetrahydro-1-naphthyl, thienyl, benzo[b]thienyl, naphtho[2,3-b]thienyl, thianthrenyl, dibenzofuryl, chromenyl, xan- thenyl, phenoxathiinyl, pyrrolyl, imidazolyl, pyrazolyl, pyrazinyl, pyrimidinyl, pyridazinyl, indol- izinyl, isoindolyl, indolyl, indazolyl, purinyl, quinolizinyl, isoquinolyl, quinolyl, phthalazinyl, naphthyridinyl, quinoxalinyl, quinazolinyl, cinnolinyl, pteridinyl, carbazolyl, β-carbolinyl, phen- anthridinyl, acridinyl, perimidinyl, phenanthrolinyl, phenazinyl, isothiazolyl, phenothiazinyl, isoxazolyl, furazanyl, biphenyl, terphenyl, fluorenyl or phenoxazinyl or any of these carbocyc- Nc or heterocyclic groups substituted by CrC₄alkyl-, CrC₄alkoxy-, CrC₄alkylthio-, hydroxyl-, halo-, amino-, CrC₄alkylamino-, phenylamino- or di(CrC₄alkyl)amino is, for example, 1- naphthyl, 2-naphthyl, 1-phenylamino-4-naphthyl, 1-methylnaphthyl, 2-methylnaphthyl, 1- methoxy-2-naphthyl, 2-methoxy-1 -naphthyl, 1-dimethylamino-2-naphthyl, 1 ,2-dimethyl-4- naphthyl, 1 ,2-dimethyl-6-naphthyl, 1 ,2-dimethyl-7-naphthyl, 1 ,3-dimethyl-6-naphthyl, 1 ,4-di- methyl-6-naphthyl, 1 ,5-dimethyl-2-naphthyl, 1 ,6-dimethyl-2-naphthyl, 1-hydroxy-2-naphthyl, 2-hydroxy-1 -naphthyl, 1 ,4-dihydroxy-2-naphthyl, 7-phenanthryl, 1 -anthryl, 2-anthryl, 9- anthryl, 3-benzo[b]thienyl, 5-benzo[b]thienyl, 2-benzo[b]thienyl, 4-dibenzofuryl, 4,7-dibenzo- furyl, 4-methyl-7-dibenzofuryl, 2-xanthenyl, 8-methyl-2-xanthenyl, 3-xanthenyl, 2- phenoxathiinyl, 2,7-phenoxathiinyl, 2-pyrrolyl, 3-pyrrolyl, 5-methyl-3-pyrrolyl, 2-imidazolyl, 4- imidazolyl, 5-imidazolyl, 2-methyl-4-imidazolyl, 2-ethyl-4-imidazolyl, 2-ethyl-5-imidazolyl, 3- pyrazolyl, 1-methyl-3-pyrazolyl, 1-propyl-4-pyrazolyl, 2-pyrazinyl, 5,6-dimethyl-2-pyrazinyl, 2- indolizinyl, 2-methyl-3-isoindolyl, 2-methyl-1 -isoindolyl, 1-methyl-2-indolyl, 1-methyl-3-indolyl, 1 ,5-dimethyl-2-indolyl, 1-methyl-3-indazolyl, 2,7-dimethyl-8-purinyl, 2-methoxy-7-methyl-8- purinyl, 2-quinolizinyl, 3-isoquinolyl, 6-isoquinolyl, 7-isoquinolyl, isoquinolyl, 3-methoxy-6-iso- quinolyl, 2-quinolyl, 6-quinolyl, 7-quinolyl, 2-methoxy-3-quinolyl, 2-methoxy-6-quinolyl, 6-phthalazinyl, 7-phthalazinyl, 1-methoxy-6-phthalazinyl, 1 ,4-dimethoxy-6-phthalazinyl, 1 ,8-naphthyridin-2-yl, 2-quinoxalinyl, 6-quinoxalinyl, 2,3-dimethyl-6-quinoxalinyl, 2,3-dimeth- oxy-6-quinoxalinyl, 2-quinazolinyl, 7-quinazolinyl, 2-dimethylamino-6-quinazolinyl, 3-cinnolinyl, 6-cinnolinyl, 7-cinnolinyl, 3-methoxy-7-cinnolinyl, 2-pteridinyl, 6-pteridinyl, 7-pteridinyl, 6,7-dimethoxy-2-pteridinyl, 2-carbazolyl, 3-carbazolyl, 9-methyl-2-carbazolyl, 9-methyl-3-carbazolyl, β-carbolin-3-yl, 1-methyl-β-carbolin-3-yl, 1-methyl-β-carbolin-6-yl, 3-phenanthridinyl, 2-acridinyl, 3-acridinyl, 2-perimidinyl, 1-methyl-5-perimidinyl, 5-phenanthrolinyl, 6-phenanthrolinyl, 1-phenazinyl, 2-phenazinyl, 3-isothiazolyl,

4-isothiazolyl, 5-isothiazolyl, 2-phenothiazinyl, 3-phenothiazinyl, 10-methyl-3-phenothiazinyl, 3-isoxazolyl, 4-isoxazolyl, 5-isoxazolyl, 4-methyl-3-furazanyl, 2-phenoxazinyl or 10-methyl- 2-phenoxazinyl.

Particular preference is given to unsubstituted or CrC₄alkyl-, CrC₄alkoxy-, CrC₄alkylthio-, hydroxyl-, phenylamino- or di(CrC₄alkyl)amino-substituted naphthyl, phenanthryl, anthryl, 5,6,7,8-tetrahydro-2-naphthyl, 5,6,7,8-tetrahydro-1-naphthyl, thienyl, benzo[b]thienyl, naph- tho[2,3-b]thienyl, thianthrenyl, dibenzofuryl, chromenyl, xanthenyl, phenoxathiinyl, pyrrolyl, isoindolyl, indolyl, phenothiazinyl, biphenyl, terphenyl, fluorenyl or phenoxazinyl, for example, 1 -naphthyl, 2-naphthyl, 1-phenylamino-4-naphthyl, 1-methylnaphthyl, 2-methylnaphthyl, 1- methoxy-2-naphthyl, 2-methoxy-1 -naphthyl, 1-dimethylamino-2-naphthyl, 1 ,2-dimethyl-4- naphthyl, 1 ,2-dimethyl-6-naphthyl, 1 ,2-dimethyl-7-naphthyl, 1 ,3-dimethyl-6-naphthyl, 1 ,4-di- methyl-6-naphthyl, 1 ,5-dimethyl-2-naphthyl, 1 ,6-dimethyl-2-naphthyl, 1-hydroxy-2-naphthyl, 2-hydroxy-1 -naphthyl, 1 ,4-dihydroxy-2-naphthyl, 7-phenanthryl, 1 -anthryl, 2-anthryl, 9- anthryl, 3-benzo[b]thienyl, 5-benzo[b]thienyl, 2-benzo[b]thienyl, 4-dibenzofuryl, 4,7-dibenzo- furyl, 4-methyl-7-dibenzofuryl, 2-xanthenyl, 8-methyl-2-xanthenyl, 3-xanthenyl, 2-pyrrolyl, 3- pyrrolyl, 2-phenothiazinyl, 3-phenothiazinyl, 10-methyl-3-phenothiazinyl.

Halogen (halo) is, for example, chlorine, bromine or iodine. Preference is given to chlorine.

Alkanoyl having up to 25 C-atoms is a branched or unbranched radical, for example, formyl, acetyl, propionyl, butanoyl, pentanoyl, hexanoyl, heptanoyl, octanoyl, nonanoyl, decanoyl, undecanoyl, dodecanoyl, tridecanoyl, tetradecanoyl, pentadecanoyl, hexadecanoyl, hepta- decanoyl, octadecanoyl, eicosanoyl or docosanoyl. Preference is given to alkanoyl having 2 to 18, especially 2 to 12, for example 2 to 6 C-atoms. Particular preference is given to acetyl.

C₂-C₂5alkanoyl substituted by a di(CrC₆alkyl)phosphonate group is, for example, (CH₃CH₂O)₂POCH₂CO-, (CH₃O)₂POCH₂CO-, (CH₃CH₂CH₂CH₂O)₂POCH₂CO-, (CH₃CH₂O)₂POCH₂CH₂CO-, (CH₃O)₂POCH₂CH₂CO-, (CH₃CH₂CH₂CH₂O)₂POCH₂CH₂CO-, (CH₃CH₂O)₂PO(CH₂)₄CO-, (CH₃CH₂O)₂PO(CH₂)SCO- or (CH₃CH₂O)₂PO(CH₂)₁₇CO-.

Alkanoyloxy having up to 25 C-atoms is a branched or unbranched radical, for example, for- myloxy, acetoxy, propionyloxy, butanoyloxy, pentanoyloxy, hexanoyloxy, heptanoyloxy, oc- tanoyloxy, nonanoyloxy, decanoyloxy, undecanoyloxy, dodecanoyloxy, tridecanoyloxy, tet- radecanoyloxy, pentadecanoyloxy, hexadecanoyloxy, heptadecanoyloxy, octadecanoyloxy, eicosanoyloxy or docosanoyloxy. Preference is given to alkanoyloxy having 2 to 18, especially 2 to 12, for example 2 to 6 C-atoms. Particular preference is given to acetoxy.

Alkenoyl having 3 to 25 C-atoms is a branched or unbranched radical, for example, prope- noyl, 2-butenoyl, 3-butenoyl, isobutenoyl, n-2,4-pentadienoyl, 3-methyl-2-butenoyl, n-2-oc- tenoyl, n-2-dodecenoyl, iso-dodecenoyl, oleoyl, n-2-octadecenoyl or n-4-octadecenoyl. Preference is given to alkenoyl having 3 to 18, especially 3 to 12, for example 3 to 6, in particular 3 to 4 C-atoms.

C₃-C₂₅alkenoyl interrupted by oxygen, sulphur or N — R₁₄ is, for example,

CH₃OCH₂CH₂CH=CHCO- or CH₃OCH₂CH₂OCH=CHCO-.

Alkenoyloxy having 3 to 25 C-atoms is a branched or unbranched radical, for example, pro- penoyloxy, 2-butenoyloxy, 3-butenoyloxy, isobutenoyloxy, n-2,4-pentadienoyloxy, 3-methyl- 2-butenoyloxy, n-2-octenoyloxy, n-2-dodecenoyloxy, iso-dodecenoyloxy, oleoyloxy, n-2-octa- decenoyloxy or n-4-octadecenoyloxy. Preference is given to alkenoyloxy having 3 to 18, es- pecially 3 to 12, for example 3 to 6, in particular 3 to 4 C-atoms.

C₃-C₂₅alkenoyloxy interrupted by oxygen, sulphur or N — R₁₄ is, for example,

CH₃OCH₂CH₂CH=CHCOO- or CH₃OCH₂CH₂OCH=CHCOO-.

C₃-C₂₅alkanoyl interrupted by oxygen, sulphur or N — R₁₄ is, for example,

CH₃-O-CH₂CO-, CH₃-S-CH₂CO-, CH₃-NH-CH₂CO-, CH₃-N(CH₃)-CH₂CO-, CH₃-O-CH₂CH₂-O-CH₂CO-, CH₃-(O-CH₂CH₂-)₂O-CH₂CO-, CH₃-(O-CH₂CH₂-)₃O-CH₂CO- or CH₃-(O-CH₂CH₂-)₄O-CH₂CO-. C₃-C₂5alkanoyloxy interrupted by oxygen, sulphur or N — R₁₄ is, for example,

CH₃-O-CH₂COO-, CH₃-S-CH₂COO-, CH₃-NH-CH₂COO-, CH₃-N(CH₃)-CH₂COO-, CH₃-O-CH₂CH₂-O-CH₂COO-, CH₃-(O-CH₂CH₂-)₂O-CH₂COO-, CH₃-(O-CH₂CH₂-)₃O-CH₂COO- or CH₃-(O-CH₂CH₂-)₄O-CH₂COO-. C₆-C₉cycloalkylcarbonyl is, for example, cyclopentylcarbonyl, cyclohexylcarbonyl, cyclohep- tylcarbonyl or cyclooctylcarbonyl. Cyclohexylcarbonyl is preferred.

C6-Cgcycloalkylcarbonyloxy is, for example, cyclopentylcarbonyloxy, cyclohexylcarbonyloxy, cycloheptylcarbonyloxy or cyclooctylcarbonyloxy. Cyclohexylcarbonyloxy is preferred.

Ci-Ci₂alkyl-substituted benzoyl, which preferably carries 1 to 3, especially 1 or 2 alkyl groups, is, for example, o-, m- or p-methylbenzoyl, 2,3-dimethylbenzoyl, 2,4-dimethylbenzoyl, 2,5-dimethylbenzoyl, 2,6-dimethylbenzoyl, 3,4-dimethylbenzoyl, 3,5-dimethylbenzoyl, 2- methyl-6-ethylbenzoyl, 4-tert-butylbenzoyl, 2-ethylbenzoyl, 2,4,6-trimethylbenzoyl, 2,6-di- methyl-4-tert-butylbenzoyl or 3,5-di-tert-butylbenzoyl. Preferred substituents are CrC₈alkyl, especially CrC₄alkyl. Ci-C"i₂alkyl-substituted benzoyloxy, which preferably carries 1 to 3, especially 1 or 2 alkyl groups, is, for example, o-, m- or p-methylbenzoyloxy, 2,3-dimethylbenzoyloxy, 2,4-dimethyl- benzoyloxy, 2,5-dimethylbenzoyloxy, 2,6-dimethylbenzoyloxy, 3,4-dimethylbenzoyloxy, 3,5-dimethylbenzoyloxy, 2-methyl-6-ethylbenzoyloxy, 4-tert-butylbenzoyloxy, 2-ethyl-ben- zoyloxy, 2,4,6-trimethylbenzoyloxy, 2,6-dimethyl-4-tert-butylbenzoyloxy or 3,5-di-tert-butyl- benzoyloxy. Preferred substituents are CrC₈alkyl, especially CrC₄alkyl.

Alkyl having up to 25 C-atoms is a branched or unbranched radical, for example, methyl, ethyl, propyl, isopropyl, n-butyl, sec-butyl, isobutyl, tert-butyl, 2-ethylbutyl, n-pentyl, isopentyl, 1-methylpentyl, 1 ,3-dimethylbutyl, n-hexyl, 1-methylhexyl, n-heptyl, isoheptyl, 1 ,1 ,3,3- tetramethylbutyl, 1-methylheptyl, 3-methylheptyl, n-octyl, 2-ethylhexyl, 1 ,1 ,3-trimethylhexyl, 1 ,1 ,3,3-tetramethylpentyl, nonyl, decyl, undecyl, 1-methylundecyl, dodecyl, 1 ,1 ,3,3,5,5- hexamethylhexyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, octadecyl, eicosyl or docosyl. One of the preferred meanings of R₂ and R₄ is, for example, CrCi₈alkyl. A particularly preferred meaning of R₄ is CrC₄alkyl.

Alkenyl having 3 to 25 C-atoms is a branched or unbranched radical, for example, propenyl, 2-butenyl, 3-butenyl, isobutenyl, n-2,4-pentadienyl, 3-methyl-2-butenyl, n-2-octenyl, n-2-do- decenyl, iso-dodecenyl, oleyl, n-2-octadecenyl or n-4-octadecenyl. Preference is given to alkenyl having 3 to 18, especially 3 to 12, for example 3 to 6, in particular 3 to 4 C-atoms. Alkenyloxy having 3 to 25 C-atoms is a branched or unbranched radical, for example, prop- enyloxy, 2-butenyloxy, 3-butenyloxy, isobutenyloxy, n-2,4-pentadienyloxy, 3-methyl-2- butenyloxy, n-2-octenyloxy, n-2-dodecenyloxy, iso-dodecenyloxy, oleyloxy, n-2-octadeceny- loxy or n-4-octadecenyloxy. Preference is given to alkenyloxy having 3 to 18, especially 3 to 12, for example 3 to 6, in particular 3 to 4 C-atoms.

Alkynyl having 3 to 25 C-atoms is a branched or unbranched radical, for example, propynyl ( — CH₂-CΞΞΞCH ), 2-butynyl, 3-butynyl, n-2-octynyl, or n-2-dodecynyl. Preference is given to alkynyl having 3 to 18, especially 3 to 12, for example 3 to 6, in particular 3 to 4 C-atoms.

Alkynyloxy having 3 to 25 C-atoms is a branched or unbranched radical, for example, pro- pynyloxy ( — OCH₂- CΞΞΞCH ), 2-butynyloxy, 3-butynyloxy, n-2-octynyloxy, or n-2- dodecynyloxy. Preference is given to alkynyloxy having 3 to 18, especially 3 to 12, for example 3 to 6, in particular 3 to 4 C-atoms.

C₂-C₂5alkyl interrupted by oxygen, sulphur or N — R₁₄ is, for example, CH₃-O-CH₂-,

CH₃-S-CH₂-, CH₃-NH-CH₂-, CH₃-N(CH₃)-CH₂-, CH₃-O-CH₂CH₂-O-CH₂-, CH₃-(O-CH₂CH₂-)₂O-CH₂-, CH₃-(O-CH₂CH₂-)₃O-CH₂- or CH₃-(O-CH₂CH₂-)₄O-CH₂-.

Cj-Cgphenylalkyl is, for example, benzyl, α-methylbenzyl, α,α-dimethylbenzyl or 2-phenyl- ethyl. Benzyl and α,α-dimethylbenzyl are preferred.

C₇-C₉phenylalkyl which is unsubstituted or substituted on the phenyl radical by 1-3 CrC₄alkyl is, for example, benzyl, α-methylbenzyl, α,α-dimethylbenzyl, 2-phenylethyl, 2-methylbenzyl, 3-methylbenzyl, 4-methylbenzyl, 2,4-dimethylbenzyl, 2,6-dimethylbenzyl or 4-tert-butylbenzyl. Benzyl is preferred.

C7-C₂₅phenylalkyl which is unsubstituted or substituted on the phenyl radical by 1-3 Cr

C₄alkyl and is interrupted by oxygen, sulphur or N — R₁₄ is a branched or unbranched

radical, for example, phenoxymethyl, 2-methylphenoxymethyl, 3-methylphenoxymethyl, 4- methylphenoxymethyl, 2,4-dimethylphenoxymethyl, 2,3-dimethylphenoxymethyl, phenyl- thiomethyl, N-methyl-N-phenylmethyl, N-ethyl-N-phenylmethyl, 4-tert-butylphenoxymethyl, 4- tert-butylphenoxyethoxymethyl, 2,4-di-tert-butylphenoxymethyl, 2,4-di-tert-butylphenoxyeth- oxymethyl, phenoxyethoxyethoxyethoxymethyl, benzyloxymethyl, benzyloxyethoxymethyl, N- benzyl-N-ethylmethyl or N-benzyl-N-isopropylmethyl. C₇-C₉phenylalkoxy is, for example, benzyloxy, α-methylbenzyloxy, α,α-dimethylbenzyloxy or 2-phenylethoxy. Benzyloxy is preferred.

C₁-C₄alkyl-substit.ut.ed phenyl, which preferably contains 1 to 3, especially 1 or 2 alkyl groups, is, for example, o-, m- or p-methylphenyl, 2,3-dimethylphenyl, 2,4-dimethylphenyl, 2,5-di- methylphenyl, 2,6-dimethylphenyl, 3,4-dimethylphenyl, 3,5-dimethylphenyl, 2-methyl-6-ethyl- phenyl, 4-tert-butylphenyl, 2-ethylphenyl or 2,6-diethylphenyl.

CrC₄alkyl-substituted phenoxy, which preferably contains 1 to 3, especially 1 or 2 alkyl groups, is, for example, o-, m- or p-methylphenoxy, 2,3-dimethylphenoxy, 2,4-dimethylphe- noxy, 2,5-dimethylphenoxy, 2,6-dimethylphenoxy, 3,4-dimethylphenoxy, 3,5-dimethylphe- noxy, 2-methyl-6-ethylphenoxy, 4-tert-butylphenoxy, 2-ethylphenoxy or 2,6-diethylphenoxy.

Unsubstituted or Ci-C₄alkyl-substituted Cs-Cβcycloalkyl is, for example, cyclopentyl, methyl- cyclopentyl, dimethylcyclopentyl, cyclohexyl, methylcyclohexyl, dimethylcyclohexyl, trimethyl- cyclohexyl, tert-butylcyclohexyl, cycloheptyl or cyclooctyl. Preference is given to cyclohexyl and tert-butylcyclohexyl. Unsubstituted or CrC₄alkyl-substituted C₅-C₈cycloalkoxy is, for example, cyclopentoxy, me- thylcyclopentoxy, dimethylcyclopentoxy, cyclohexoxy, methylcyclohexoxy, dimethylcyclo- hexoxy, trimethylcyclohexoxy, tert-butylcyclohexoxy, cycloheptoxy or cyclooctoxy. Preference is given to cyclohexoxy and tert-butylcyclohexoxy.

Alkoxy having up to 25 C-atoms is a branched or unbranched radical, for example, methoxy, ethoxy, propoxy, isopropoxy, n-butoxy, isobutoxy, pentoxy, isopentoxy, hexoxy, heptoxy, octoxy, decyloxy, tetradecyloxy, hexadecyloxy or octadecyloxy. Preference is given to alkoxy having 1 to 12, especially 1 to 8, for example 1 to 6 C-atoms.

C₂-C₂5alkoxy interrupted by oxygen, sulphur or N — R₁₄ is, for example,

CH₃-O-CH₂CH₂O-, CH₃-S-CH₂CH₂O-, CH₃-NH-CH₂CH₂O-, CH₃-N(CH₃)-CH₂CH₂O-, CH₃-O-CH₂CH₂-O-CH₂CH₂O-, CH₃-(O-CH₂CH₂-)₂O-CH₂CH₂O-,

CH₃-(O-CH₂CH₂-)₃O-CH₂CH₂O- or CH₃-(O-CH₂CH₂-)₄O-CH₂CH₂O-.

Alkylthio having up to 25 C-atoms is a branched or unbranched radical, for example, me- thylthio, ethylthio, propylthio, isopropylthio, n-butylthio, isobutylthio, pentylthio, isopentylthio, hexylthio, heptylthio, octylthio, decylthio, tetradecylthio, hexadecylthio or octadecylthio. Pref- erence is given to alkylthio having 1 to 12, especially 1 to 8, for example 1 to 6 C-atoms. Alkylamino having up to 4 C-atoms is a branched or unbranched radical, for example, me- thylamino, ethylamino, propylamino, isopropylamino, n-butylamino, isobutylamino or tert-bu- tylamino.

Di(Ci-C₄alkyl)amino also means that the two radicals independently of one another are branched or unbranched, for example, dimethylamino, methylethylamino, diethylamino, methyl-n-propylamino, methylisopropylamino, methyl-n-butylamino, methylisobutylamino, ethylisopropylamino, ethyl-n-butylamino, ethylisobutylamino, ethyl-tert-butylamino, diethylamino, diisopropylamino, isopropyl-n-butylamino, isopropylisobutylamino, di-n-butylamino or diisobutylamino. Alkanoylamino having up to 25 C-atoms is a branched or unbranched radical, for example, formylamino, acetylamino, propionylamino, butanoylamino, pentanoylamino, hexanoylamino, heptanoylamino, octanoylamino, nonanoylamino, decanoylamino, undecanoylamino, dode- canoylamino, tridecanoylamino, tetradecanoylamino, pentadecanoylamino, hexadecane- oylamino, heptadecanoylamino, octadecanoylamino, eicosanoylamino or docosanoylamino. Preference is given to alkanoylamino having 2 to 18, especially 2 to 12, for example 2 to 6 C- atoms. d-Ciβalkylene is a branched or unbranched radical, for example, methylene, ethylene, propylene, trimethylene, tetramethylene, pentamethylene, hexamethylene, heptamethylene, octamethylene, decamethylene, dodecamethylene or octadecamethylene. Preference is given to Ci-Ci₂alkylene, especially CrC₈alkylene.

A CrC₄alkyl-substituted C₅-Ci₂cycloalkylene ring, which preferably contains 1 to 3, especially 1 or 2 branched or unbranched alkyl group radicals is, for example, cyclopentylene, methyl- cyclopentylene, dimethylcyclopentylene, cyclohexylene, methylcyclohexylene, dimethylcy- clohexylene, trimethylcyclohexylene, tert-butylcyclohexylene, cycloheptylene, cyclooctylene or cyclodecylene. Preference is given to cyclohexylene and tert-butylcyclohexylene.

C₂-Ci₈alkylene interrupted by oxygen, sulphur or N — R₁₄ is, for example, -CH₂-O-CH₂-,

-CH₂-S-CH₂-, -CH₂-NH-CH₂-, -CH₂-N(CH₃)-CH₂-, -CH₂-O-CH₂CH₂-O-CH₂-, -CH₂-(O-CH₂CH₂-)₂O-CH₂-, -CH₂-(O-CH₂CH₂-)₃O-CH₂- , -CH₂-(O-CH₂CH₂-)₄O-CH₂- or -CH₂CH₂-S-CH₂CH₂-. C₂-Ci₈alkenylene is, for example, vinylene, methylvinylene, octenylethylene or dodecenyl- ethylene. Preference is given to C₂-Cβalkenylene. Alkylidene having 2 to 20 C-atoms is, for example, ethylidene, propylidene, butylidene, pen- tylidene, 4-methylpentylidene, heptylidene, nonylidene, tridecylidene, nonadecylidene, 1-methylethylidene, 1-ethylpropylidene or 1-ethylpentylidene. Preference is given to C₂-C₈- alkylidene. Phenylalkylidene having 7 to 20 C-atoms is, for example, benzylidene, 2-phenylethylidene or 1-phenyl-2-hexylidene. Preference is given to C₇-C₉-phenylalkylidene.

C₅-C₈cycloalkylene is a saturated hydrocarbon group having two free valencies and at least one ring unit and is, for example, cyclopentylene, cyclohexylene, cycloheptylene or cyclooc- tylene. Preference is given to cyclohexylene. C₇-C₈bicycloalkylene is, for example, bicycloheptylene or bicyclooctylene.

Unsubstituted or CrC₄alkyl-substituted phenylene or naphthylene is, for example, 1 ,2-, 1 ,3-, 1 ,4-phenylene, 1 ,2-, 1 ,3-, 1 ,4-, 1 ,6-, 1 ,7-, 2,6- or 2,7-naphthylene. 1 ,4-Phenylene is preferred.

A CrC₄alkyl-substituted C₅-C₈cycloalkylidene ring, which preferably contains 1 to 3, espe- cially 1 or 2 branched or unbranched alkyl group radicals is, for example, cyclopentylidene, methylcyclopentylidene, dimethylcyclopentylidene, cyclohexylidene, methylcyclohexylidene, dimethylcyclohexylidene, trimethylcyclohexylidene, tert-butylcyclohexylidene, cycloheptyli- dene or cyclooctylidene. Preference is given to cyclohexylidene and tert-butylcyclohexylidene. A mono-, di- or trivalent metal cation is preferably an alkali metal, alkaline earth metal or aluminium cation, for example, Na⁺, K⁺, Mg⁺⁺, Ca⁺⁺ or Al⁺⁺⁺.

A particularly preferred composition of the invention contains at least one 3-arylbenzofu- ranone of formula I, wherein, if n = 1 , R₁ is phenyl which is unsubstituted or substituted in para-position by Ci-Ci₈alkylthio or di(Ci-C₄alkyl)amino; mono- to penta-substituted alkyl- phenyl containing together a total of at most 18 C-atoms in the 1 to 5 alkyl substituents; naphthyl, biphenyl, terphenyl, phenanthryl, anthryl, fluorenyl, carbazolyl, thienyl, pyrrolyl, phenothiazinyl or 5,6,7,8-tetrahydronaphthyl, each of which is unsubstituted or substituted by Ci-C₄alkyl, Ci-C₄alkoxy, Ci-C₄alkylthio, hydroxy or amino.

Preference is given to compounds of the formula I in which, if n is 2,

Ri₂ and Ri₃ are phenylene, X is oxygen or -NR_3r, and R₃i is Ci-C₄alkyl.

Preference is also given to compounds of the formula I in which, if n is 1 ,

R₁ is unsubstituted or CrC₄alkyl-, CrC₄alkoxy-, Ci-C₄alkylthio-, hydroxyl-, halo-, amino-, Ci-C₄alkylamino- or di(Ci-C₄-alkyl)amino-substituted naphthyl, phenanthryl, thienyl, dibenzo- furyl, carbazolyl, fluorenyl or a radical of the formula II, wherein

R₇, R₈, Rg, Rio and Rn independently of one another are hydrogen, chlorine, bromine, hydroxyl, CrC₁₈alkyl, C₂-C₁₈alkyl interrupted by oxygen or sulphur; CrC₁₈alkoxy, C₂-C₁₈alkoxy interrupted by oxygen or sulphur; CrCi₈alkylthio, C₃-Ci₂alkenyloxy, C₃-Ci₂alkynyloxy, Cy-Cgphenylalkyl, C₇-Cgphenylalkoxy, unsubstituted or Ci-C₄alkyl-substituted phenyl; phenoxy, cyclohexyl, C₅-C₈cycloalkoxy, Ci-C₄alkylamino, di(Ci-C₄-alkyl)amino,

Ci-Ci₂alkanoyl, C3-Ci₂alkanoyl interrupted by oxygen or sulphur; Ci-Ci₂alkanoyloxy, C₃-Ci₂alkanoyloxy interrupted by oxygen or sulphur; d-C^alkanoylamino, C₃-Ci₂alkenoyl, C₃-Ci₂alkenoyloxy, cyclohexylcarbonyl, cyclohexylcarbonyloxy, benzoyl or Ci-C₄alkyl-substi-

tuted benzoyl; benzoyloxy or Ci-C₄alkyl-substituted benzoyloxy; — O — C — C — R₁₅ or

R ^X,19

^R20 ^R21 — O — C — C — O — R,. or, in the alternative, in formula Il the radicals R₇ and R₈ or the i i ²³

H R22 radicals R₈ and Rn, together with the C-atoms to which they are attached, form a benzene ring,

R₁₅ is hydroxyl, CrC₁₂alkoxy or — N,

R₁₈ and R-ig independently of one another are hydrogen or Ci-C₄alkyl, R₂0 is hydrogen,

R₂-₁ is hydrogen, phenyl, CrC₁₈alkyl, C₂-C₁₈alkyl interrupted by oxygen or sulphur; C₇-Cgphenylalkyl, C₇-C₁₈-phenylalkyl which is unsubstituted or substituted on the phenyl radical by 1-3 C-ι-C₄alkyl and is interrupted by oxygen or sulphur, or, in the alternative, the radicals R₂O and R₂₁, together with the C-atoms to which they are attached, form a cyclohexylene ring which is unsubstituted or substituted by 1-3 Ci-C₄alkyl,

R₂₂ is hydrogen or Ci-C₄alkyl, R₂₃ is hydrogen, CrCi₈alkanoyl, C₃-Ci₈alkenoyl, C₃-Ci₂alkanoyl interrupted by oxygen or sulphur; C₂-Ci₂alkanoyl substituted by a di(CrC₆-alkyl)phosphonate group; C₆-Cgcycloalkyl- carbonyl, benzoyl,

0

R₂₄ and R₂₅ independently of one another are hydrogen or Ci-Ci₂alkyl, R₂6 is hydrogen or CrC₄alkyl,

R₂₇ is CrCi₂alkylene, C₂-C₈alkenylene, C₂-C₈alkylidene, C₇-Ci₂phenylalkylidene, C₅-C₈cyclo- alkylene or phenylene,

R ^Xo24 R₂₈ is hydroxyl, Ci-Ci₂alkoxy or — N \

R₂₅

R₂g is oxygen or -NH-,

R₃₀ is Ci-Ci₈alkyl or phenyl, and s is 1 or 2.

Preference is likewise given to compounds of the formula I in which, if n is 1 , R₁ is phenanthryl, thienyl, dibenzofuryl, unsubstituted or CrC₄alkyl-substituted carbazolyl; or is fluorenyl; or R₁ is a radical of the formula II, wherein

R₇, R₈, Rg, R₁O and R₁₁ independently of one another are hydrogen, chlorine, hydroxyl, Ci-Ci₈alkyl, Ci-Ci₈alkoxy, Ci-Ci₈alkylthio, C₃-C₄alkenyloxy, C₃-C₄alkinyloxy,

^R20 ^R21

C₂-Ci₈alkanoyloxy, phenyl, benzoyl, benzoyloxy or — o — C — C — 0-R₂₃ ,

H R₂₂ R₂0 is hydrogen,

R₂₁ is hydrogen, phenyl or CrCi₈alkyl, or, in the alternative, the radicals R₂₀ and R₂i, together with the C-atoms to which they are attached, form a cyclohexylene ring which is un- substituted or substituted by 1-3 CrC₄alkyl, R₂₂ is hydrogen or d-C₄alkyl, and

R₂3 is hydrogen, CrCi₈alkanoyl or benzoyl.

Particular preference is given to compounds of the formula I in which, if n is 1 ,

R₇, R₈, Rg, R₁0 and Rn independently of one another are hydrogen, Ci-C₄alkylthio or phenyl.

Of particular interest is a composition containing at least one compound of the formula I in which R₂, R3, R₄ and R₅ independently of one another are hydrogen, chlorine, CrCi₈alkyl, benzyl, phenyl, C₅-C₈cycloalkyl, Ci-Ci₈alkoxy, Ci-Ci₈alkylthio, Ci-Ci₈alkanoyloxy, Ci-Ci₈alk- anoylamino, C3-Ci₈alkenoyloxy or benzoyloxy; or, in the alternative, the radicals R₂ and R3 or the radicals R₃ and R₄ or the radicals R₄ and R₅, together with the C-atoms to which they are attached, form a benzene ring, R₄ is additionally -(CH₂)_p-CORi₅ or -(CH₂)_qOH, or, if R₃, R₅ and R₆ are hydrogen, R₄ is additionally a radical of the formula III,

R₁₅ is hydroxyl, Ci-Ci₂alkoxy or — N,

R₁6 and Ri₇ are methyl groups or, together with the C atom to which they are attached, form a C₅-C₈cycloalkylidene ring which is unsubstituted or substituted by 1-3 Ci-C₄alkyl,

R₂₄ and R₂₅ independently of one another are hydrogen or Ci-Ci₂alkyl, p is 1 or 2, and q is 2, 3, 4, 5 or 6.

Also of particular interest is a composition containing at least one compound of the formula I in which at least two of the radicals R₂, R₃, R₄ and R₅ are hydrogen.

Of special interest is a composition containing at least one compound of the formula I in which R₃ and R₅ are hydrogen.

Of very special interest is composition containing at least one compound of the formula I in which

R₂ is C_rC₄alkyl, R₃ is hydrogen,

R₄ is CrC₄alkyl or, if R₆ is hydrogen, R₄ is additionally a radical of the formula III,

R₅ is hydrogen, and

Ri6 and Ri₇, together with the C atom to which they are attached, form a cyclohexylidene ring.

The following compounds are examples of the benzofuran-2-one type which are particularly suitable in the composition of the invention: 3-[4-(2-acetoxyethoxy)phenyl]-5,7-di-tert-butyl- benzofuran-2-one; 5,7-di-tert-butyl-3-[4-(2-stearoyloxyethoxy)phenyl]benzofuran-2-one; 3,3'- bis[5,7-di-tert-butyl-3-(4-[2-hydroxyethoxy]phenyl)benzofuran-2-one]; 5,7-di-tert-butyl-3-(4- ethoxyphenyl)benzofuran-2-one; 3-(4-acetoxy-3,5-dimethylphenyl)-5,7-di-tert-butylbenzofu- ran-2-one; 3-(3,5-dimethyl-4-pivaloyloxy-phenyl)-5,7-di-tert-butyl-benzofuran-2-one; 5,7-di- tert-butyl-3-phenylbenzofuran-2-one; 5,7-di-tert-butyl-3-(3,4-dimethylphenyl)-benzofuran-2- one; 5,7-di-tert-butyl-3-(2,3-dimethylphenyl)benzofuran-2-one.

Also of special interest is a composition containing at least one compound of the formula V

in which

R₂ is hydrogen or d-C₆alkyl,

R₃ is hydrogen,

R₄ is hydrogen or CrC₆alkyl,

R₅ is hydrogen,

R₇, R₈, Rg, Rio and Rn independently of one another are hydrogen, Ci-C₄alkyl or Ci-C₄al- koxy, with the proviso that at least two of the radicals R₇, R₈, Rg, R-io or R₁₁ are hydrogen.

Very particular preference is given to a composition containing at least one compound of the formula Va or Vb

(Va) (Vb)

or a mixture of the two compounds of the formula Va and Vb.

The sterically hindered amine stabilizers contain at least one moiety of formula

where Gi, G₂, G3, G₄ and G₅ are independently alkyl of 1 to 8 C-atoms or Gi and G₂ or G3 and G₄ together are pentamethylene.

The hindered amines are disclosed for example in U.S. Pat. Nos. 5,004, 770, 5,204,473, 5,096,950, 5,300,544, 5, 112,890, 5, 124,378, 5, 145,893, 5,216, 156, 5,844,026, 5,980, 783, 6,046,304, 6, 117,995, 6,271,377, 6,297,299, 6,392,041, 6,376,584 and 6,472,456, and the published U.S. application. Nos. 09/714, 717, filed Nov. 16, 2000 and 10/485,377, filed August 6, 2002.

U.S. Pat. Nos. 6,271,377, 6,392,041 and 6,376,584, cited above disclose hindered hy- droxyalkoxyamine stabilizers. Suitable hindered amines include for example:

1 ) 1 -cyclohexyloxy^^.θ.θ-tetramethyM-octadecylaminopiperidine,

2) bis(2,2,6,6-tetramethylpiperidin-4-yl) sebacate,

3) bis(1-acetoxy-2,2,6,6-tetramethylpiperidin-4-yl) sebacate, 4) bis(1 ,2,2,6,6-pentamethyl-4-yl) sebacate,

5) bis(1 -cyclohexyloxy^^.θ.θ-tetramethylpiperidin^-yl) sebacate,

6) bis(1-octyloxy-2,2,6,6-tetramethylpiperidin-4-yl) sebacate;

7) bis(1-acyl-2,2,6,6-tetramethylpiperidin-4-yl) sebacate, 8) bis(1 ,2,2,6,6-pentamethyl-4-piperidyl) n-butyl-3,5-di-tert-butyl-4-hydroxybenzyl- malonate

9) 2,4-bis[(1-cyclohexyloxy-2,2,6,6-tetramethylpiperidin-4-yl)butylamino]-6-(2-hydroxy- ethylamino-s-triazine,

10) bis(1 -cyclohexyloxy^^.θ.θ-tetramethylpiperidin^-yl) adipate, 1 1 ) 2,4-bis[(1 -cyclohexyloxy^^.θ.θ-piperidin^-yljbutylaminol-θ-chloro-s-triazine,

12) 1 -(2-hydroxy-2-methylpropoxy)-4-hydroxy-2,2,6,6-tetramethylpiperidine,

13) 1 -(2-hydroxy-2-methylpropoxy)-4-oxo-2,2,6,6-tetramethylpipeιϊdine,

14) 1 -(2-hydroxy-2-methylpropoxy)-4-octadecanoyloxy-2,2,6,6-tetramethylpiperidine,

15) bis(1 -(2-hydroxy-2-methylpropoxy)-2,2,6,6-tetramethylpiperidin-4-yl) sebacate, 16) bis(1 -(2-hydroxy-2-methylpropoxy)-2,2,6,6-tetramethylpiperidin-4-yl) adipate,

17) 2,4-bis{N-[1 -(2-hydroxy-2-methylpropoxy)-2,2,6,6-tetramethylpiperidin-4-yl]-N- butylamino}-6-(2-hydroxyethylamino)-s-triazine,

18) 4-benzoyl-2,2,6,6-tetramethylpiperidine,

19) di-(1 ,2,2,6,6-pentamethylpiperidin-4-yl) p-methoxybenzylidenemalonate, 20) 4-stearyloxy-2,2,6,6-tetramethylpiperidine,

21 ) bis(1-octyloxy-2,2,6,6-tetramethylpiperidyl) succinate,

22) 1 ,2,2,6,6-pentamethyl-4-aminopiperidine,

23) 2-undecyl-7,7,9,9-tetramethyl-1-oxa-3,8-diaza-4-oxo-spiro[4,5]decane,

24) tris(2,2,6,6-tetramethyl-4-piperidyl) nitrilotriacetate, 25) tris(2-hydroxy-3-(amino-(2,2,6,6-tetramethylpiperidin-4-yl)propyl) nitrilotriacetate,

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

27) tetrakis(1 ,2,2,6,6-pentamethyl-4-piperidyl)-1 ,2,3,4-butane-tetracarboxylate,

28) 1 ,1 '-(1 ,2-ethanediyl)-bis(3,3,5,5-tetramethylpiperazinone), 29) 3-n-octyl-7,7,9,9-tetramethyl-1 ,3,8-triazaspiro[4.5]decan-2,4-dione, SOJ δ-acetyl-S-dodecyl^J.Θ.Θ-tetramethyl-I .S.δ-triazaspiro^.δldecane^^-dione, 31 ) 3-dodecyl-1-(2,2,6,6-tetramethyl-4-piperidyl)pyrrolidin-2,5-dione, 32) 3-dodecyl-1 -(1 ,2,2,6,6-pentamethyl-4-piperidyl)pyrrolidine-2,5-dione, 33) N,N'-bis-formyl-N,N'-bis(2,2,6,6-tetramethyl-4-piperidyl)hexamethylenediainine,

34) the reaction product of 2,4-bis[(1-cyclohexyloxy-2,2,6,6-piperidin-4-yl)butylamino]- 6-chloro-s-triazine with N,N'-bis(3-aminopropyl)ethylenediamine),

35) the condensate of 1-(2-hydroxyethyl)-2,2,6,6-tetramethyl-4-hydroxypiperidine and succinic acid, 36) linear or cyclic condensates of N,N'-bis(2,2,6,6-tetramethyl-4-piperidyl)-hexame- thylenediamine and 4-tert-octylamino-2,6-dichloro-1 ,3,5-triazine,

37) linear or cyclic condensates of N,N'-bis(2,2,6,6-tetramethyl-4-piperidyl)-hexame- thylenediamine and 4-cyclohexylamino-2,6-dichloro-1 ,3,5-triazine,

38) linear or cyclic condensates of N,N'-bis-(2,2,6,6-tetramethyl-4-piperidyl)hexame- thylenediamine and 4-morpholino-2,6-dichloro-1 ,3,5-triazine,

39) linear or cyclic condensates of N,N'-bis-(1 ,2,2,6,6-pentamethyl-4-piperidyl)hexa- methylenediamine and 4-morpholino-2,6-dichloro-1 ,3,5-triazine,

40) the condensate of 2-chloro-4,6-bis(4-n-butylamino-2,2,6,6-tetramethylpiperidyl)- 1 ,3,5-triazine and 1 ,2-bis(3-aminopropylamino)ethane, 41 ) the condensate of 2-chloro-4,6-di-(4-n-butylamino-1 ,2,2,6,6-pen- tamethylpiperidyl)-1 ,3,5-triazine and 1 ,2-bis-(3-aminopropylamino)ethane,

42) a reaction product of 7,7,9, θ-tetramethyl^-cycloundecyl-i-oxa-S.δ-diaza^-oxo- spiro [4,5]decane and epichlorohydrin,

43) poly[methyl,(3-oxy-(2,2,6,6-tetramethylpiperidin-4-yl)propyl)] siloxane, CAS#182635-99-0,

44) reaction product of maleic acid anhydride-Ci₈-C₂₂-α-olefin-copolymer with 2,2,6,6- tetramethyl-4-aminopiperidine,

45) the oligomeric compound which is the condensation product of 4,4'-hexamethyle- nebis(amino-2,2,6,6-tetramethylpiperidine) and 2,4-dichloro-6-[(2,2,6,6-tetramethyl- piperidin-4-yl)butylamino]-s-triazine end-capped with 2-chloro-4,6-bis(dibutylamino)-s- triazine,

46) the oligomeric compound which is the condensation product of 4,4'-hexamethyle- nebis(amino-1 ,2,2,6,6-pentaamethylpiperidine) and 2,4-dichloro-6-[(1 ,2,2,6,6-pentaa- methylpiperidin-4-yl)butylamino]-s-triazine end-capped with 2-chloro-4,6-bis(dibutyl- amino)-s-triazine,

47) the oligomeric compound which is the condensation product of 4,4'-hexamethyle- nebis(amino-1 -propoxy-2,2,6,6-tetramethylpiperidine) and 2,4-dichloro-6-[(1 -propoxy- 2,2,6,6-tetramethylpiperidin-4-yl)butylamino]-s-triazine end-capped with 2-chloro-4,6- bis(dibutylamino)-s-triazine,

48) the oligomeric compound which is the condensation product of 4,4'-hexamethyle- nebis(amino-1 -acyloxy-2,2,6,6-tetramethylpiperidine) and 2,4-dichloro-6-[(1 -acyloxy- 2,2,6,6-tetramethylpiperidin-4-yl)butylamino]-s-triazine end-capped with 2-chloro-4,6- bis(dibutylamino)-s-triazine and 49) product obtained by reacting a product, obtained by reacting 1 ,2-bis(3-aminopro- pylamino)ethane with cyanuric chloride, with (2,2,6,6-tetramethylpiperidin-4-yl)butyl- amine.

Also included are the sterically hindered N-H, N-methyl, N-methoxy, N-propoxy, N-octyloxy, N-cyclohexyloxy, N-acyloxy and N-(2-hydroxy-2-methylpropoxy) analogues of any of the above mentioned compounds. For example, replacing an N-H hindered amine with an N- methyl hindered amine would be employing the N-methyl analogue in place of the N-H.

The hindered phenolic antioxidants are for example

1.1. Alkylated monophenols, for example 2,6-di-tert-butyl-4-methylphenol, 2-tert-butyl-4,6-di- methylphenol, 2,6-di-tert-butyl-4-ethylphenol, 2,6-di-tert-butyl-4-n-butylphenol, 2,6-di-tert-bu- tyl-4-isobutylphenol, 2,6-dicyclopentyl-4-methylphenol, 2-(α-methylcyclohexyl)-4,6-dimethyl- phenol, 2,6-dioctadecyl-4-methylphenol, 2,4,6-tricyclohexylphenol, 2,6-di-tert-butyl-4-metho- xymethylphenol, nonylphenols which are linear or branched in the side chains, 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 thereof. 1.2. Alkylthiomethylphenols, for example 2,4-dioctylthiomethyl-6-tert-butylphenol, 2,4-dioc- tylthiomethyl-6-methylphenol, 2,4-dioctylthiomethyl-6-ethylphenol, 2,6-di-dodecylthiomethyl- 4-nonylphenol. 1.3. Hydroquinones and alkylated hydroquinones, for example 2,6-di-tert-butyl-4-methoxy- phenol, 2,5-di-tert-butylhydroquinone, 2,5-di-tert-amylhydroquinone, 2,6-diphenyl-4-octade- cyloxyphenol, 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, bis-(3 , 5-d i-tert-buty l-4-hy- droxyphenyl) adipate.

1.4. Tocopherols, for example α-tocopherol, β-tocopherol, γ-tocopherol, δ-tocopherol and mixtures thereof (Vitamin E).

1.5. Hydroxylated thiodiphenyl ethers, for example 2,2'-thiobis(6-tert-butyl-4-methylphenol), 2,2'-thiobis(4-octylphenol), 4,4'-thiobis(6-tert-butyl-3-methylphenol), 4,4'-thiobis(6-tert-butyl-2- methylphenol), 4,4'-thiobis-(3,6-di-sec-amylphenol), 4,4'-bis(2,6-dimethyl-4-hydroxy- phenyl)disulphide.

1.6. Alkylidenebisphenols, 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'-ethylidenebis(4,6-di-tert-butyl- phenol), 2,2'-ethylidenebis(6-tert-butyl-4-isobutylphenol), 2,2'-methylenebis[6-(α-methylben- zyl)-4-nonylphenol], 2,2'-methylenebis[6-(α,α-dimethylbenzyl)-4-nonylphenol], 4,4'-methy- lenebis(2,6-di-tert-butylphenol), 4,4'-methylenebis(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-methyl-phenyl)-3-n-dodecylmercaptobutane, ethylene glycol bis[3,3-bis(3-tert-bu- tyl-4-hydroxyphenyl)butyrate], bis(3-tert-butyl-4-hydroxy-5-methyl-phenyl)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)pro- pane, 2,2-bis-(5-tert-butyl-4-hydroxy2-methylphenyl)-4-n-dodecylmercaptobutane, 1 ,1 ,5,5- tetra-(5-tert-butyl-4-hydroxy-2-methylphenyl)pentane.

1.7. Benzyl compounds, 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-butyl- benzylmercaptoacetate, tris(3,5-di-tert-butyl-4-hydroxybenzyl)amine, 1 ,3,5-tri-(3,5-di-tert-butyl-4-hydroxybenzyl)-2,4,6-trimethylbenzene, di-(3,5-di-tert-butyl-4-hy- droxybenzyl) sulphide, S.δ-di-tert-butyl^-hydroxybenzyl-mercapto-acetic acid isooctyl ester, bis-(4-tert-butyl-3-hydroxy-2,6-dimethylbenzyl)dithiol terephthalate, 1 ,3,5-tris-(3,5-di-tert-bu- tyl-4-hydroxybenzyl) isocyanurate, 1 ,3,5-tris-(4-tert-butyl-3-hydroxy-2,6-dimethylbenzyl) iso- cyanurate, S.δ-di-tert-butyM-hydroxybenzyl-phosphoric acid dioctadecyl ester and 3,5-di- tert-butyl-4-hydroxybenzyl-phosphoric acid monoethyl ester, calcium-salt.

1.8. Hydroxybenzylated malonates, for example dioctadecyl-2,2-bis-(3,5-di-tert-butyl-2-hy- droxybenzyl)-malonate, di-octadecyl-2-(3-tert-butyl-4-hydroxy-5-methylbenzyl)-malonate, di- dodecylmercaptoethyl-2,2-bis-(3,5-di-tert-butyl-4-hydroxybenzyl)malonate, bis[4-(1 ,1 ,3,3- tetramethylbutyl)phenyl]-2,2-bis(3,5-di-tert-butyl-4-hydroxybenzyl)malonate.

1.9. Aromatic hydroxybenzyl compounds, for example 1 ,3,5-tris-(3,5-di-tert-butyl-4-hydroxy- benzyl)-2,4,6-trimethylbenzene, 1 ,4-bis(3,5-di-tert-butyl-4-hydroxybenzyl)-2,3,5,6-tetrame- thylbenzene, 2,4,6-tris(3,5-di-tert-butyl-4-hydroxybenzyl)phenol. 1.10. Triazine compounds, for example 2,4-bis(octylmercapto)-6-(3,5-di-tert-butyl-4-hydroxy- anilino)-1 ,3,5-triazine, 2-octylmercapto-4,6-bis(3,5-di-tert-butyl-4-hydroxyanilino)-1 ,3,5-triaz- ine, 2-octylmercapto-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-(3,5-di-tert-butyl-4-hydroxyben- zyl)isocyanurate, 1 ,3,5-tris(4-tert-butyl-3-hydroxy-2,6-dimethylbenzyl)isocyanurate, 2,4,6-tris- (3,5-di-tert-butyl-4-hydroxyphenylethyl)-1 ,3,5-triazine, 1 ,3,5-tris(3,5-di-tert-butyl-4-hydroxy- phenylpropionyl)-hexahydro-1 ,3,5-triazine, 1 ,3,5-tris(3,5-dicyclohexyl-4-hydroxyben- zyl)isocyanurate.

1.11. Benzylphosphonates, for example dimethyl-2,5-di-tert-butyl-4-hydroxybenzylphospho- nate, diethyl-3,5-di-tert-butyl-4-hydroxybenzylphosphonate, dioctadecyl3,5-di-tert-butyl-4-hy- droxybenzylphosphonate, dioctadecyl-δ-tert-butyl^-hydroxy-S-methylbenzylphosphonate, the calcium salt of the monoethyl ester of 3,5-di-tert-butyl-4-hydroxybenzylphosphonic acid.

1.12. Acylaminophenols, for example 4-hydroxy-lauric acid anilide, 4-hydroxy-stearic acid anilide, 2,4-bis-octylmercapto-6-(3,5-tert-butyl-4-hydroxyanilino)-s-triazine and octyl-N-(3,5- di-tert-butyl-4-hydroxyphenyl)-carbamate. 1.13. Esters of β-(3,5-di-tert-butyl-4-hvdroxyphenyl)propionic acid with mono- or polyhydric alcohols, e.g. with methanol, ethanol, n-octanol, i-octanol, octadecanol, 1 ,6-hexanediol, 1 ,9- nonanediol, ethylene glycol, 1 ,2-propanediol, neopentyl glycol, thiodiethylene glycol, diethy- lene glycol, triethylene glycol, pentaerythritol, tris(hydroxyethyl) isocyanurate, N₁N'- bis(hydroxyethyl)oxamide, 3-thiaundecanol, 3-thiapentadecanol, trimethylhexanediol, trimethylolpropane, 4-hydroxymethyl-1 -phospha^.θ.y-trioxabicyclo^^^loctane.

1.14. Esters of β-(5-tert-butyl-4-hvdroxy-3-methylphenyl)propionic acid with mono- or polyhydric alcohols, e.g. with methanol, ethanol, n-octanol, i-octanol, octadecanol, 1 ,6-hexanediol, 1 ,9-nonanediol, ethylene glycol, 1 ,2-propanediol, neopentyl glycol, thiodiethylene glycol, di- ethylene glycol, triethylene glycol, pentaerythritol, tris(hydroxyethyl) isocyanurate, N,N'-bis- (hydroxyethyl)oxamide, 3-thiaundecanol, 3-thiapentadecanol, trimethylhexanediol, trimethyl- olpropane, 4-hydroxymethyl-1-phospha-2,6,7-trioxabicyclo[2.2.2]octane.

1.15. Esters of β-(3,5-dicvclohexyl-4-hvdroxyphenyl)propionic acid with mono- or polyhydric alcohols, e.g. with methanol, ethanol, octanol, octadecanol, 1 ,6-hexanediol, 1 ,9-nonanediol, ethylene glycol, 1 ,2-propanediol, neopentyl glycol, thiodiethylene glycol, diethylene glycol, triethylene glycol, pentaerythritol, tris(hydroxyethyl)isocyanurate, N₁N'- bis(hydroxyethyl)oxamide, 3-thiaundecanol, 3-thiapentadecanol, trimethylhexanediol, trimethylolpropane, 4-hydroxymethyl-1-phospha-2,6,7-trioxabicyclo[2.2.2]octane. 1.16. Esters of 3,5-di-tert-butyl-4-hvdroxyphenyl acetic acid with mono- or polyhydric alcohols, e.g. with methanol, ethanol, octanol, octadecanol, 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)ox- amide, 3-thiaundecanol, 3-thiapentadecanol, trimethylhexanediol, trimethylolpropane, 4-hy- droxymethyl-1 -phospha^.θj-trioxabicycloβ^^octane.

1.17. Amides of β-(3,5-di-tert-butyl-4-hvdroxyphenyl)propionic acid e.g. N,N'-bis(3,5-di-tert- butyl-4-hydroxyphenylpropionyl)hexamethylenediamide, N,N'-bis(3,5-di-tert-butyl-4-hydroxy- phenylpropionyl)trimethylenediamide, N,N'-bis(3,5-di-tert-butyl-4-hydroxyphenylpropionyl)hy- drazide, N,N'-bis[2-(3-[3,5-di-tert-butyl-4-hydroxyphenyl]propionyloxy)ethyl]oxamide (Nau- gard^®XL-1 supplied by Uniroyal).

Each of the 3-arylbenzofuranone and hindered amine light stabilizers, and the optional phenolic antioxidant, are employed at levels of about 5 ppm to about 5000 ppm, for example from about 50 ppm to about 5000 ppm, for example from about 100 to about 5000 ppm by weight, based on the weight of the biodiesel fuel. For example, each of the additives are pre- sent from about 150 to about 4000 ppm, from about 200 to about 3000 ppm, or from about 250 to about 2500 ppm by weight, based on the weight of the biodiesel fuel. In certain instances, the levels may be as high as about 1 %, about 2% or about 3% by weight, based on the weight of the biodiesel fuel.

The stabilized biodiesel fuels exhibit increased storage stability vs. unstabilized samples. Degradation of biodiesel fuels under the conditions of heat, light or oxygen is observed by the formation of carboxylic acids, peroxides, aldehydes and alcohols.

Examples The Rancimat test, developed by the food industry, is employed to test the oxidative stability of soy biodiesel (methyl ester of soy fatty acid). A 3.0 g sample of soy biodiesel is held at 1 11.7°C and exposed to a bubbling stream of air (10 liter per hour). The sample vessel is vented to a secondary container, where the off-gases are bubbled through 60 ml of distilled water. The test measures the volatile oxidation decomposition products such as peroxides, alcohols, aldehydes and carboxylic acids. The volatile decomposition products (chiefly formic acid) are swept through the sample vessel and vented into the secondary container where they are trapped by the distilled water. The conductivity of the water is constantly monitored as a function of time through use of an electrode. The inflection point (not a specific value) of the conductivity curve is the measured induction time. It should be pointed out that some samples will be highly conductive before the inflection point is achieved, while others will only be slightly conductive. An increase of the induction time indicates an increase in oxidative stability. Results are in the table below. Levels of additive are in weight percent based on the weight of the biodiesel. Rancimat Induction Time

sample additive Induction Time (hours)

1 (control) none 5.0

2 250 ppm A 6.6

3 2500 ppm A 8.8

4 2500 ppm B 12.7

Additive A is bis-(1 ,1 ,2,2,6,6-pentamethyl-4-piperidyl) sebacate; B is 3-(3,4-dimethylphenyl)- 5,7-di-tert-butyl-benzofuran-2-one. A 6 hour induction time is necessary to meet the EN 14214 specification.

Claims

1. A biodiesel fuel composition stabilized against the deleterious effects of heat, light and oxygen, which composition comprises

A biodiesel fuel and

Optionally, one or more additives selected from the group consisting of the hindered phenolic antioxidants.

2. A composition according to claim 1 comprising one or more 3-arylbenzofuranone stabilizers of formula I

in which, if n is 1 ,

Ri is naphthyl, phenanthryl, anthryl, 5,6,7,8-tetrahydro-2-naphthyl, 5,6,7,8-tetrahydro-1- naphthyl, thienyl, benzo[b]thienyl, naphtho[2,3-b]thienyl, thianthrenyl, dibenzofuryl, chromenyl, xanthenyl, phenoxathiinyl, pyrrolyl, imidazolyl, pyrazolyl, pyrazinyl, pyrimidinyl, pyridazinyl, indolizinyl, isoindolyl, indolyl, indazolyl, purinyl, quinolizinyl, isoquinolyl, quinolyl, phthalazinyl, naphthyridinyl, quinoxalinyl, quinazolinyl, cinnolinyl, pteridinyl, carbazolyl, β- carbolinyl, phenanthridinyl, acridinyl, perimidinyl, phenanthrolinyl, phenazinyl, isothiazolyl, phenothiazinyl, isoxazolyl, furazanyl, biphenyl, terphenyl, fluorenyl or phenoxazinyl, or any of these carbocyclic or heterocyclic groups substituted by CrC₄alkyl-, d-C₄alkoxy-, Ci-C₄alkyl- thio-, hydroxyl-, halo-, amino-, C-ι-C₄alkylamino-, phenylamino- or di(Ci-C₄alkyl)amino; or R₁ is a radical of the formula Il

and if n is 2,

R₁ is unsubstituted or d-C₄alkyl- or hydroxy-substituted phenylene or naphthylene; or is

R₂, R3, R₄ and R₅ independently of one another are hydrogen, chlorine, hydroxyl, Ci-C₂5alkyl, C₇-C₉phenylalkyl, unsubstituted or Ci-C₄alkyl-substituted phenyl; unsubstituted or Ci-C₄alkyl- substituted C₅-C₈cycloalkyl; CrCi₈alkoxy, CrCi₈alkylthio, CrC₄alkylamino, di(C_r C₄alkyl)amino, CrC₂5alkanoyloxy, Ci-C₂5alkanoylamino, C₃-C₂5alkenoyloxy, C₃-C₂₅alkanoyloxy which is interrupted by oxygen, sulphur or N — R₁₄ ; C₆-C₉cycloalkyl-

carbonyloxy, benzoyloxy or

Ci-C"i₂alkyl-substituted benzoyloxy; or, in the alternative, the radicals R₂ and R3 or the radicals R₃ and R₄ or the radicals R₄ and R₅, together with the C-atoms to which they are attached, form a benzo ring, R₄ is additionally -(CH₂)_p-CORi₅ or -(CH₂)_qOH or, if R₃, R₅ and Re are hydrogen, R₄ is additionally a radical of the formula III

in which R₁ is defined as indicated above for n = 1 , Re is hydrogen or a radical of the formula IV

where R₄ is other a radical of the formula III and Ri is defined as indicated above for n = 1 , R₇, Re, Rg, R-io and Rn independently of one another are hydrogen, halogen, hydroxyl, CrC₂5alkyl, C₂-C₂5alkyl interrupted by oxygen, sulphur or N — R₁₄ ; CrC₂5alkoxy,

C₃-C₂₅alkenyloxy, C₃-C₂₅alkynyl, C₃-C₂₅alkynyloxy, C₇-C₉phenylalkyl, C₇-C₉phenylalkoxy, un- substituted or Ci-C₄alkyl-substituted phenyl; unsubstituted or Ci-C₄alkyl-substituted phenoxy; unsubstituted or CrC₄alkyl-substituted C₅-C₈cycloalkyl; unsubstituted or d-C₄alkyl-substi- tuted C₅-C₈cycloalkoxy; CrC₄alkylamino, di(CrC₄alkyl)amino, CrC₂₅alkanoyl, C₃-C₂₅alkanoyl interrupted by oxygen, sulphur or N — R₁₄ ; CrC₂₅alkanoyloxy, C₃-C₂₅alkanoyloxy inter¬

rupted by oxygen, sulphur or N — R₁₄ ; Ci-C₂₅alkanoylamino, C₃-C₂₅alkenoyl, C₃-

C₂₅alkenoyl interrupted by oxygen, sulphur or N — R₁₄ ; C₃-C₂₅alkenoyloxy, C₃-

Cgcycloalkylcarbonyloxy, benzoyl or Ci-Ci₂alkyl-substituted benzoyl; benzoyloxy or Cr Ci₂alkyl-substituted benzoyloxy; — O — C — C-R₁₅ or — o — C — C — 0-R₂₃ , or

R₁₉ H R₂₂ else, in formula II, the radicals R₇ and R₈ or the radicals R₈ and Rn, together with the C-at- oms to which they are attached, form a benzo ring,

Ri₂ and Ri₃ independently of one another are unsubstituted or CrC₄alkyl-substituted phenylene or naphthylene, Ri₄ is hydrogen or CrC₈alkyl,

r i / ^R^

Ri5 is hydroxyl, —_Q ^' ^ MH , C_rCi₈alkoxy or — N_χ

^R25

Ri₆ and Ri₇ independently of one another are hydrogen, CF₃, d-C^alkyl or phenyl, or R₁₆ and Ri7, together with the C atom to which they are attached, form a C₅-C₈cycloalkylidene ring which is unsubstituted or substituted by 1-3 CrC₄alkyl;

R-iβ and R₁₉ independently of one another are hydrogen, Ci-C₄alkyl or phenyl, R₂O is hydrogen or d-C₄alkyl,

R₂₁ is hydrogen, unsubstituted or Ci-C₄alkyl-substituted phenyl; Ci-C₂5alkyl, C₂-C₂salkyl inter¬

rupted by oxygen, sulphur or N — R₁₄ ; C₇-C₉phenylalkyl which is unsubstituted or

substituted on the phenyl radical by 1-3 CrC₄alkyl; C₇-C₂5phenylalkyl which is unsubstituted or substituted on the phenyl radical by 1-3 CrC₄alkyl and interrupted by oxygen, sulphur or

N — R₁₄ , or, in the alternative, the radicals R₂0 and R₂₁, together with the C-atoms to

which they are attached, form a Cs-C-^cycloalkylene ring which is unsubstituted or substituted by 1-3 CrC₄alkyl; R₂₂ is hydrogen or CrC₄alkyl,

R₂3 is hydrogen, CrC₂5alkanoyl, C₃-C₂5alkenoyl, C₃-C₂5alkanoyl interrupted by oxygen, sul¬

phur or N — R₁₄ ; C₂-C₂5alkanoyl substituted by a di(CrC6alkyl)phosphonate group;

C₆-C₉cycloalkylcarbonyl, thenoyl, furoyl, benzoyl or d-C^alkyl-substituted benzoyl;

R₂₄ and R₂₅ independently of one another are hydrogen or CrCi₈alkyl,

R₂₆ is hydrogen or CrC₈alkyl,

\

N — R₁₄ ; C₂-Ci₈alkenylene, C₂-C₂oalkylidene, C₇-C₂₀phenylalkylidene,

C₅-C₈cycloalkylene, C₇-C₈bicycloalkylene, unsubstituted or d-C₄alkyl-substituted phenylene,

/ ^R24

R₂₈ is hydroxyl, | _₀ ^~ — M^Γ+ | , C_rCi₈alkoxy or — N, \

^X25

O R₂₉ is oxygen, -NH- or _N _Q__NH _ _R

^■30

R₃₀ is Ci-Ci₈alkyl or phenyl,

R₃₁ is hydrogen or Ci-Ci₈alkyl,

M is an r-valent metal cation,

X is a direct bond, oxygen, sulphur or -NR₃₁-, n is 1 or 2, p is O, 1 or 2, q is 1 , 2, 3, 4, 5 or 6, r is 1 , 2 or 3, and s is O, 1 or 2.

3. A composition according to claim 2 wherein the 3-arylbenzofuranones are of formula I wherein n = 1 , R₁ is phenyl which is unsubstituted or substituted in para-position by CrCi₈alkylthio or di(Ci-C₄alkyl)amino; mono- to penta-substituted alkyphenyl containing together a total of at most 18 C-atoms in the 1 to 5 alkyl substituents; naphthyl, biphenyl, ter- phenyl, phenanthryl, anthryl, fluorenyl, carbazolyl, thienyl, pyrrolyl, phenothiazinyl or 5,6,7,8- tetrahydronaphthyl, each of which is unsubstituted or substituted by CrC₄alkyl, Ci-C₄alkoxy, CrC₄alkylthio, hydroxy or amino.

4. A composition according to claim 2 wherein the 3-arylbenzofuranones are of formula I wherein n is 2, R₁ is -R₁₂-X-R-i3-, R-₁₂ and R-₁3 are phenylene, X is oxygen or -NR₃₁-, and R₃₁ is Ci-C₄alkyl. 5. A composition according to claim 2 wherein the 3-arylbenzofuranones are selected from the group consisting of 3-[4-(2-acetoxyethoxy)phenyl]-5,7-di-tert-butyl-benzofuran-2-one; 5,7- di-tert-butyl-3-[4-(2-stearoyloxyethoxy)phenyl]benzofuran-2-one;

3,3'-bis[5,7-di-tert-butyl-3-(4-[2-hydroxyethoxy]phenyl)benzofuran-2-one]; 5,7-di-tert-butyl-3- (4-ethoxyphenyl)benzofuran-2-one; 3-(4-acetoxy-3,5-dimethylphenyl)-5,7-di-tert-butylbenzo- furan-2-one; 3-(3,

5-dimethyl-4-pivaloyloxy-phenyl)-5,7-di-tert-butyl-benzofuran-2-one; 5,7-di- tert-butyl-3-phenylbenzofuran-2-one; 5,7-di-tert-butyl-3-(3,4-dimethylphenyl)-benzofuran-2- one and 5,7-di-tert-butyl-3-(2,3-dimethylphenyl)-benzofuran-2-one.

6. A composition according to claim 1 comprising one or more hindered amine light stabilizers that contain at least one moiety of formula

where d, G₂, G₃, G₄ and G₅ are independently alkyl of 1 to 8 C-atoms or Gi and G₂ or G₃ and G₄ together are pentamethylene.

7. A composition according to claim 6 where the hindered amine is an N-H, N-methyl, N- methoxy, N-propoxy, N-octyloxy, N-cyclohexyloxy, N-acyloxy or an N-(2-hydroxy-2-methyl- propoxy) substituted amine.

8. A composition according to claim 1 comprising one or more hindered amine light stabilizers and one or more hindered phenolic antioxidants.

9. A composition according to claim 8, where the hindered phenolic antioxidants are selected from the group consisting of butylated hydroxytoluene, butylated hydroxyanisole, tocopherol, benzylphosphonates, esters of β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid with mono- or polyhydric alcohols, esters of β-(5-tert-butyl-4-hydroxy-3-methylphenyl)propionic acid with mono- or polyhydric alcohols, esters of β-(3,5-dicyclohexyl-4-hydroxyphenyl)propionic acid with mono- or polyhydric alcohols and esters of 3,5-di-tert-butyl-4-hydroxyphenyl acetic acid with mono- or polyhydric alcohols.

10. A process for the stabilization of a biodiesel fuel against the deleterious effects of heat, light and oxygen, which process comprise incorporating into a biodiesel fuel an effective stabilizing amount of one or more additives selected from the group consisting of the 3-arylben- zofuranone stabilizers and the hindered amine light stabilizers and optionally, one or more additives selected from the group consisting of the hindered phenolic antioxidants.