EP0280650A1 - Use of predetermined benztriazole derivatives as light-protecting agents for ink jet recording materials - Google Patents

Abstract

A UV absorber of the formula I, <IMAGE> <??>in which n is 1 to 4, R represents H, C1-C12-alkyl, C5-C8-cycloalkyl, phenyl or C7-C9-phenylalkyl, R<1> represents H, C1, C1-C4-alkyl or C1-C4-alkoxy and R<2> is an n-valent hydrophilic group, are particularly suitable for the stabilisation to light of ink jet prints. In this context, the compound of the formula I is added to the recording material, preferably in a surface coating. Such compounds also have the advantage that they form particularly stable emulsions.

Description

The invention relates to the use of certain UV absorbers of the 2- (2-hydroxyphenyl) benzotriazole type as light stabilizers for recording materials for ink-jet printing and to the recording materials stabilized by means of these compounds against light damage.

Inkjet printing is a very fast printing process that can be controlled by electrical signals. A fine jet of ink droplets is sprayed through a nozzle onto the recording material. The ink is a solution of a dye in an aqueous or non-aqueous solvent. The recording material should quickly and permanently absorb the dye of the ink. Usually specially prepared papers or plastic foils are used, which are coated with a dye-binding layer. Because of the fineness of the nozzles, pigments are rarely used, but mainly dyes that are completely dissolved in the inkjet medium. However, these dyes generally have a lower light fastness than the color pigments common in conventional printing inks. As a result, records made in inkjet printing can only be stored for a limited period under the influence of light. When stored in the light for a long time, they begin to fade or change color.

In order to solve this problem, it has already been proposed (US-A-4,256,493) to add a water-soluble UV absorber to the ink. By interacting with the dye, solid particles can precipitate in the ink and block the fine nozzle. One therefore went the other way and added light stabilizers to the recording material. GB-A-2 088 777 proposes the addition of UV absorbers of the benzotriazole type in combination with sterically hindered phenols as a measure against the fading of the dyes. These additives are added in solution to a coating material made up of colorless fillers, a binder and a dye receptor or mordant, which is applied to one side of the recording material (usually paper). The protection of light from hard copy prints, including ink jet prints, by adding UV absorbers of various types to the recording material is described in Research Disclosure No. 24239 (1984, 284).

worin n 1 bis 4 ist,

• R Wasserstoff, Ci-C_i2-Alkyl, C₅-C₈-Cycloalkyl, Phenyl oder C₇-C₉-Phenylalkyl bedeuet,
• R¹ Wasserstoff, Chlor, Ci-C₄-Alkyl oder Ci-C₄-Alkoxy bedeutet und im Falle von n = 1 auch -COOR³ bedeutet und
• R² a) im Falle von n = 1 eine Gruppe -OR³ oder NR⁴R⁵ bedeutet,
• b) im Falle von n = 2 eine zweiwertige Gruppe -O-R^6-O-, -O-R^6-N(R⁷)-, -N(R⁷)-R^8-N(R⁷)- oder
  
  bedeutet,
• c) im Falle von n = 3 eine dreiwertige Gruppe -O-
  
  -O- oder -N(R⁷)-R⁸-
  
  -R^8-N(R⁷)-bedeutet und
• d) im Falle von n = 4 eine vierwertige Gruppe
  
  oder -N(R⁷)-R⁸-
  
  -R^8'-
  
  -R⁸-N(R⁷)- bedeutet, worin
• R³ Wasserstoff, durch ein oder mehrere -OH oder -O-COR¹⁰ substituiertes C₁-C₁₈-Alkyl, durch ein oder mehrere -0- oder -N(R⁷)-unterbrochenes C₃-C₃₀-Alkyl, das durch ein oder mehrere Gruppen -OH oder -O-COR¹⁰ substituierte sein kann, unsubstituiertes oder durch -OH substituiertes C₅-C₁₂-Cycloalkyl, unsubstituiertes oder durch -OH substituiertes C₂-C₁₈-Alkenyl, C₇-C₁₅-Phenylalkyl oder -Alkylphenylalkyl, Glycidyl, Furfuryl oder eine Glykosylgruppe bedeuet, R⁴ und R⁵ unabhängig voneinander Wasserstoff, C₁-C₁₈-Alkyl, C_i-C₄-Hydroxyalkyl, durch -0- oder -N(R⁷)- unterbrochenes C₃-C₁₈-Alkyl, C₆-C₁₂-Cycloalkyl, unsubstituiertes oder durch Hydroxyl, Ci-C₄-Alkyl, Ci-C₄-Alkoxy oder Halogen substituiertes Phenyl, C₃-C₈-Alkenyl, C₇-C₁₅-Phenylalkyl oder -Alkylphenylalkyl bedeutet oder R⁴ und R⁵ zusammen mit dem N-Atom einen Pyrrolidin-, Piperidin-, Piperazin- oder Morpholinring bilden,
• R⁶ C₂-C₈-Alkylen, C₄-C₈-Alkenylen, C₄-Alkinylen, Cyclohexylen, durch ein oder mehrere -0- oder -N(R⁷)-unterbrochenes C₄-C₃₀-Alkylen oder eine Gruppe -CH₂-CH(OH)-CH₂-O-R⁹-O-CH₂-CH(OH)-CH₂- oder
  
  bedeutet,
• R⁷ Wasserstoff oder C₁-C₁₈-Alkyl bedeuet,
• R⁸ C₂-C₁₂-Alkylen, das durch ein oder mehrere -0- unterbrochen sein kann, bedeutet
• R⁹ C₂-C₈-Alkylen, durch ein oder mehrere -0- unterbrochenes C₄-C₁₀-Alkylen, Cyclohexylen, Phenylen oder eine Gruppe
  
  bedeutet,
• R¹⁰ C₁1C₁₈-Alkyl oder Phenyl bedeutet,
• R¹¹ C₃-Cio-Alkantriyl und
• R¹² C₄-C₁₂-Alkantetrayl bedeutet.

It has now been found that certain UV absorbers of the benzotriazole type are particularly suitable for this purpose. These are compounds of the formula I.

where n is 1 to 4,

• R is hydrogen, Ci-C _i2- alkyl, C ₅ -C ₈ -cycloalkyl, phenyl or C ₇ -C ₉ -phenylalkyl,
• R ^{1 is} hydrogen, chlorine, Ci-C ₄ alkyl or Ci-C ₄ alkoxy and in the case of n = 1 also means -COOR ³ and
• R ² a) in the case of n = 1 denotes a group -OR ³ or NR ⁴ R ⁵ ,
• b) in the case of n = 2 a divalent group -OR ^6- O-, -OR ^6- N (R ⁷ ) -, -N (R ⁷ ) -R ^8- N (R ⁷ ) - or
  
  means
• c) in the case of n = 3 a trivalent group -O-
  
  -O- or -N (R ⁷ ) -R ⁸ -
  
  -R ^8- N (R ⁷ ) means and
• d) in the case of n = 4 a tetravalent group
  
  or -N (R ⁷ ) -R ⁸ -
  
  -R ^{8 '} -
  
  -R ⁸ -N (R ⁷ ) - means where
• R ^{3 is} hydrogen, C ₁ -C ₁₈ -alkyl substituted by one or more -OH or -O-COR ¹⁰ , by one or more -0- or -N (R ⁷ ) -interrupted C ₃ -C ₃₀ -alkyl which by one or more groups -OH or -O-COR ¹⁰ may be substituted, unsubstituted or -OH-substituted C ₅ -C ₁₂ -cycloalkyl, unsubstituted or -OH-substituted C ₂ -C ₁₈ -alkenyl, C ₇ -C ₁₅ -phenylalkyl or -alkylphenylalkyl, glycidyl, Furfuryl or a glycosyl group means R ⁴ and R ⁵ independently of one another hydrogen, C ₁ -C ₁₈ alkyl, C _i -C ₄ hydroxyalkyl, C ₃ -C ₁₈ interrupted by -0- or -N (R ⁷ ) - Alkyl, C ₆ -C ₁₂ cycloalkyl, phenyl which is unsubstituted or substituted by hydroxyl, Ci-C ₄ alkyl, Ci-C ₄ alkoxy or halogen, C ₃ -C ₈ alkenyl, C ₇ -C ₁₅ phenylalkyl or - Means alkylphenylalkyl or R ⁴ and R ⁵ together with the N atom form a pyrrolidine, piperidine, piperazine or morpholine ring,
• R ⁶ C ₂ -C ₈ alkylene, C ₄ -C ₈ alkenylene, C ₄ alkynylene, cyclohexylene, by one or more -0- or -N (R ⁷ ) -interrupted C ₄ -C ₃₀ alkylene or one Group -CH ₂ -CH (OH) -CH ₂ -OR ⁹ -O-CH ₂ -CH (OH) -CH ₂ - or
  
  means
• R ^{7 means} hydrogen or C ₁ -C ₁₈ alkyl,
• R ^{8 is} C ₂ -C ₁₂ alkylene, which can be interrupted by one or more -0-
• R ⁹ C ₂ -C ₈ alkylene, interrupted by one or more -0- C ₄ -C ₁₀ alkylene, cyclohexylene, phenylene or a group
  
  means
• R ^{10 is} C ₁ 1C ₁₈ alkyl or phenyl,
• R ¹¹ C ₃ -Cio alkanetriyl and
• R ^{12 is} C ₄ -C ₁₂ alkanetrayl.

Some of the compounds of formula i are disclosed in EP-A-57 160 as stabilizers for organic materials, such as e.g. Polymers, lacquers or photographic materials. The preparation of these compounds is also described there. As far as the connections are new, they can be made analogously. Research Disclosure No. 22 519 (1983 [1], 6) proposes the use of such benzotriazoles as light stabilizers for reproduction materials and for the dyes contained therein. The use in inks is also mentioned there. Use in recording materials for inkjet printing is not mentioned there.

R as C ₁ -C ₁₂ alkyl can, for example, methyl, ethyl, isopropyl, n-butyl, tert-butyl, sec-butyl, tert-pentyl, sec-pentyl, n-hexyl, sec.hexyl, n-octyl .Octyl, sec.Decyl or n-dodecyl. R as cycloalkyl can in particular be cyclohexyl. R as phenylalkyl can in particular be a, a-dimethylbenzyl. R is preferably a branched alkyl radical, in particular tert-butyl.

R ¹ as C _i -C ₄ alkyl or alkoxy can be, for example, methyl, ethyl, propyl, isopropyl, butyl, tert-butyl, methoxy, ethoxy, isopropoxy, butoxy or tert-butoxy.

R ⁴ , R ⁵ , R ⁷ and R ¹⁰ as C ₁ -C ₁₈ alkyl can be unbranched or branched alkyl, such as, for example, methyl, ethyl, propyl, isopropyl, n-butyl, sec-butyl, isobutyl, tert-butyl, n-pentyl, isopentyl, n-hexyl, 2-ethylbutyl, n-octyl, isooctyl, 2-ethylhexyl, 1,1,3,3-tetraethylbutyl, n-decyl, isodecyl, n-dodecyl, 1,1,7, 7-tetramethyloctyl, n-tetradecyl or n-octadecyl.

R ³ as alkyl substituted by -OH or -OCOR ¹⁰ can, for example, 2-hydroxyethyl, 2-hydroxypropyl, 2-hydroxybutyl, 3-hydroxybutyl, 2,3-dihydroxypropyl, 2,2-di (hydroxymethyl) propyl, 4-hydroxybutyl , 6-hydroxyhexyl, 8-hydroxyoctyl, 2-acetoxyethyl, 2-propionyloxyethyl, 2-octanoyloxypropyl, 2,3-diacetyloxypropyl or 4-acetoxybutyl.

R ³ , R ⁴ , R ⁵ as C ₃ -C ₃₀ alkyl interrupted by -O- or -N (R ⁷ ) - can, for example, 2-methoxyethyl, 2-ethoxyethyl, 2-butoxyethyl, 2-isopropoxyethyl, 2-octyloxyethyl , 3,6-dioxaheptyl, 3,6,9-trioxaundecyl, 3,6,9,12-tetraoxatridecyl, 5-hydroxy-3-oxapentyl or 11-hydroxy-3,6,9-trioxaundecyl. R ³ In particular a residue (̵CH ₂ CH ₂ O) ̵ _m CH ₃ with m = 2-10.

R ⁴ and R ⁵ as C ₁ -C ₄ hydroxyalkyl can be, for example, hydroxymethyl, 2-hydroxyethyl, 2-hydroxypropyl, 3-hydroxypropyl or 2-hydroxybutyl.

R ⁴ and R ⁵ as C ₅ -C ₁₂ cycloalkyl can be, for example, cyclopentyl, cyclohexyl, methylcyclohexyl, cyclooctyl or cyclododecyl.

R ³ can also be cycloalkyl substituted by OH, for example 4-hydroxycyclohexyl.

R ³ as C ₂ -C ₁₈ alkenyl, which can be substituted by OH, can be, for example, vinyl, allyl, methallyl, 2-butenyl-1, oleyl or 4-hydroxy-2-butenyl-1. R ⁴ and R ⁵ as C ₃ -C ₈ alkenyl can in particular be allyl. R ³ , R ⁴ and R ⁵ as C ₇ -C ₁₅ phenylalkyl or alkylphenylalkyl can be, for example, benzyl, 2-phenylethyl, 1-phenylethyl, 3-phenylpropyl, 2-phenylpropyl-2, 4-methylbenzyl or 4-octylbenzyl.

R ⁴ and R ⁵ as phenyl substituted by alkyl, alkoxy or halogen can be, for example, 4-tolyl, 4-isopropylphenyl, 3-methoxyphenyl, 4-ethoxyphenyl, 4-fluorophenyl or 4-chlorophenyl.

R ⁶ and R ⁹ as C ₂ -C ₈ alkylene can be branched or straight-chain alkylene, such as, for example, 1,2-ethylene, tri-, tetra-, penta-, hexa- or octamethylene, 2,2-dimethyl-1, 3-propylene, 1,2-propylene or 1,2-butylene. R ⁸ as C ₂ -C ₁₂ alkylene can also be, for example, deca- or dodecamethylene.

R ⁶ as alkenylene or alkynylene can be, for example, 2-butenylene-1,4, 2-butynylene-1,4 or 2-methyl-2-butenylene-1,4.

CH₂CH₂- mit m = 1-6.R ⁶ and R ⁹ as alkylene interrupted by -0- or -N (R ⁷ ) - can, for example, 3-oxapentylene-1,5, 3,6-dioxaoctylene-1,8, 3,6,9-trioxaundecylene-1, 11, 3- (Methylaza) -pentylene-1,5 or 3,9-Dioxa-5- (methyla-za) -undecylene-1,11. R ⁶ is in particular a radical (̵CH ₂ CH ₂ O

CH ₂ CH ₂ - with m = 1-6.

R ¹¹ as alkanetriyl radical can be, for example, propane-1,2,3-triyl or a radical CH ₃ C (CH ₂ -) ₃ or C ₂ H ₅ C (CH ₂ -) ₃ . R ¹² as alkane tetrayl radical can be, for example, butane-1,2,3,4-tetrayl or a radical C (CH _2- ) ₄ .

Preference is given to using compounds of the formula I in which n is 1 or 2, RC _i -C ₄ alkyl, R ^{i is} hydrogen, chlorine or methoxy, R ² a) in the case of n = 1, a group --OR ³ or - NR ⁴ R ⁵ means

b) in the case of n = 2 is a group -OR ⁶ -O-, where R ^{3 is} hydrogen, C ₁ -C ₁₈ -alkyl substituted by 1 to 3 OH groups, by one or more -O-interrupted C ₃ - C ₁₈ alkyl, which may be substituted by one or more -OH, means cyclohexyl or allyl, R ⁴ and R ⁵ independently of one another Ci-C _i2 alkyl, C ₂ -C ₄ hydroxyalkyl or C ₃ -C ₁₂ alkoxyalkyl mean or R ⁴ and R ⁵ together with the N atom form a pyrrolidine, piperidine, piperazine or morpholine ring, R ⁶ C ₂ -C ₆ alkylene, interrupted by one or more -0- C ₄ -C ₁₄ alkylene or a group -CH ₂ -CH (OH) -CH ₂ -0-R ⁹ 0-CH ₂ -CH (OH) -CH ₂ -bedeutet, and R ⁹ is C ₂ -C ₄ alkylene or by one or more -O- means interrupted C ₄ -Cs alkylene. Preferred among them are those compounds of the formula I in which R is tert-butyl.

Depending on the meaning of R ² , the compounds of the formula are carboxylic acids, carboxylic esters or carboxamides. The esters are particularly suitable, in particular the compounds of the formula I, in which n is 1 or 2 and R ^{2 is} a group -OR ³ or -OR ^6- O-.

oder

bedeutet, worin u 1-9, v 1-6 und w 1-6 ist,

• b) im Falle von n = 2 eine Gruppe der Formel
  
  oder
  
  bedeutet, worin x 1-7 und y 1-4 ist.

Particular preference is given to using compounds of the formula I in which n is 1 or 2, R ^{1 is} hydrogen, chlorine or methoxy, R ² a) in the case of n = 1, a group of the formula

or

means where u is 1-9, v 1-6 and w 1-6,

• b) in the case of n = 2 a group of the formula
  
  or
  
  means where x is 1-7 and y is 1-4.

• 1) R = -OCH₂CH₂OCH₂CH₂OC₂H₅
• 2) R = -OCH₂CH₂OCH₂CH₂OC₄H₉-n
• 3) R = -OCH₂CH₂0H
• 4) R = -0 (̵ CH₂CH₂O
  
  H
• 5) R = -0 (̵ CH₂CH₂O
  
  H
• 6) R = -0 (̵ CH₂CH₂O
  
  CH₃
• 7) R = -0 (̵ CH₂CH₂O
  
  H
• ₈) _R = -O (̵ _CH2_CH2O
  
  H m = 5-7
• ₉) _R = -O (̵ CH₂CH₂O
  
  CH₃ m = ₅-₇
  

• 11) R = -NHCH₂CH₂0CH₂CH₂0CH₂CH₂0C₄H₉-n
• 12) R = -NHC(CH₂0H)₃
• 13) R = -OCH₂CH(OH)CH₂0H
• 14) R = -OCH₂CH(OH)CH₂OC₄H₉-n
• 15) R = -OCH₂CH(OH)CH₃
• 16) R = -NHCH₂CH₂OC₂H₅
• 17) R = -OCH₂CH(OH)CH₂0CH₂
  
  ₄H₉-n
• 18) R = -O-CH₂CH(OH)CH₂OC₆H₁₃-n
• 19) R = -0 ⁅ CH₂-CH(CH₃)-O
  
  H
• 20) _R = -0 ⁅ CH₂-CH(CH₃)-O
  
  H m = 3-6
• 21) R = -0 ⁅ CH₂-CH(CH₃)-O
  
  -CH₃ m = 3-6
• ₂₂) _R = -O ⁅ CH₂-CH(OH)-CH₂-O
  
  _H
• ₂₃) _R = -_O ⁅ CH₂-CH(OH)-CH₂-O
  
  _H m = 3-5

• 24) R = -OCH₂CH₂0-25) R = -0 (̵ CH₂CH₂O
  
• 26) R = -0 (̵ CH₂CH₂O
  
• 27) R = -0 (̵ CH₂CH₂O
  
• 28) R = -0 (̵ CH₂CH₂O
  
  m = 5-7
• 29) R = -0 ⁅ CH₂CH(CH₃)-O
  
• 30) R = -0 ⁅ CH₂CH(CH₃)-O
  
• 31) R = -O-CH₂CH(OH)CH₂-O-(CH₂)₈-O-CH₂CH(OH)CH₂-O-

• 32) R = -OCH₂CH₂0H
• 33) R = -0 (̵ CH₂CH₂O
  
  H
• ₃₄) _R = -O (̵ _CH2_CH2O
  
  H m = ₅-₇
• 35) R = -NH-C(CH₂0H)₃
  

• 37) R = -NH-(CH₂)₃-OCH₂CH₂0CH₂CH₂-OC₄H₉-n
• 38) R = -NH-(CH₂)₃-OC₈H₁₇
• 39) R = -OCH₂CH(OH)CH₂-OC₈H₁₇
• 40) R = -OCH₂CH₂OCH₂CH₂-OC₄H₉-n
• 41) R = -OCH₂CH₂OCH₂CH₂-OC₂H₅
• 42) R = -OCH₂CH(OH)CH₂-OCH₂CH=CH₂
• 43) R = -OCH₂CH(OH)CH₂-OC₄H₉-n

• 45) R = -OCH₂CH₂0CH₂CH₂0-46) R = -0 (̵ CH₂CH₂O
  
• ₄₇) _{R =} -O (̵ CH₂CH₂O
  
  m = ₅-₇
• 48) R = -OCH₂CH(OH)CH₂-O-(CH₂)₄-O-CH₂CH(OH)CH₂O-
  

• 49) R = -O-CH₂CH₂-O-50) R = -0 (̵ CH₂CH₂0 )̵₃
• ₅₁) _R = -_O (̵ _CH2CH2₀ )̵_m m = 5-7
  

• 52) R = -OCH₂CH₂0CH₂CH₂OCH₃
• 53) R = -0 (̵ CH₂CH₂O
  
  -H
• 54) R = -O (̵ CH₂CH₂0
  
  C₂H₅
• 55) R = -OCH₂CH(OH)CH₂0H
• ₅₆) _R = -O (̵ _CH2_CH20
  
  H m = ₈-₁₀

• 57) R = -0 (̵ CH₂CH₂O
  
• 58) R = -0 (̵ CH₂CH₂O
  
• ₅₉) _R = -O (̵ _CH₂CH₂₀
  
  m = ₈-10
  

• 60) R = tert.C₄H₉ R' = -0 (̵ CH₂CH₂O
  
  CH₃
• 61) R = tert.C₄H₉ R'= -0 (̵ CH₂CH₂O
  
  C₂H₅.
• 62) R = CH_s R' = -O (̵ CH₂CH₂O
  
  CH₃

Preference is furthermore given to compounds of the formula I in which n = 1, R ^{1 is} -COOR ^s and R ^{2 is} -OR ³ . Those compounds of the formula I which are liquid at room temperature are preferably used. Examples of individual compounds of the formula I are the compounds of the following formulas:

• 1) R = -OCH ₂ CH ₂ OCH ₂ CH ₂ OC ₂ H ₅
• 2) R = -OCH ₂ CH ₂ OCH ₂ CH ₂ OC ₄ H ₉ -n
• 3) R = -OCH ₂ CH ₂ 0H
• 4) R = -0 (̵ CH ₂ CH ₂ O
  
  H
• 5) R = -0 (̵ CH ₂ CH ₂ O
  
  H
• 6) R = -0 (̵ CH ₂ CH ₂ O
  
  CH ₃
• 7) R = -0 (̵ CH ₂ CH ₂ O
  
  H
• ₈ ) _R = -O (̵ _CH 2 _CH2O
  
  H m = 5-7
• ₉ ) _R = -O (̵ CH ₂ CH ₂ O
  
  CH ₃ m = _5-7
  

• 11) R = -NHCH ₂ CH ₂ 0CH ₂ CH ₂ 0CH ₂ CH ₂ 0C ₄ H ₉ -n
• 12) R = -NHC (CH ₂ 0H) ₃
• 13) R = -OCH ₂ CH (OH) CH ₂ 0H
• 14) R = -OCH ₂ CH (OH) CH ₂ OC ₄ H ₉ -n
• 15) R = -OCH ₂ CH (OH) CH ₃
• 16) R = -NHCH ₂ CH ₂ OC ₂ H ₅
• 17) R = -OCH ₂ CH (OH) CH ₂ 0CH ₂
  
  ₄ H ₉ -n
• 18) R = -O-CH ₂ CH (OH) CH ₂ OC ₆ H ₁₃ -n
• 19) R = -0 ⁅ CH ₂ -CH (CH ₃ ) -O
  
  H
• 20) _R = -0 ⁅ CH ₂ -CH (CH ₃ ) -O
  
  H m = 3-6
• 21) R = -0 ⁅ CH ₂ -CH (CH ₃ ) -O
  
  -CH ₃ m = 3-6
• ₂₂ ) _R = -O ⁅ CH ₂ -CH (OH) -CH ₂ -O
  
  _H
• ₂₃ ) _R = - _O ⁅ CH ₂ -CH (OH) -CH ₂ -O
  
  _H m = 3-5

• 24) R = -OCH ₂ CH ₂ 0-25) R = -0 (̵ CH ₂ CH ₂ O
  
• 26) R = -0 (̵ CH ₂ CH ₂ O
  
• 27) R = -0 (̵ CH ₂ CH ₂ O
  
• 28) R = -0 (̵ CH ₂ CH ₂ O
  
  m = 5-7
• 29) R = -0 ⁅ CH ₂ CH (CH ₃ ) -O
  
• 30) R = -0 ⁅ CH ₂ CH (CH ₃ ) -O
  
• 31) R = -O-CH ₂ CH (OH) CH ₂ -O- (CH ₂ ) ₈ -O-CH ₂ CH (OH) CH ₂ -O-

• 32) R = -OCH ₂ CH ₂ 0H
• 33) R = -0 (̵ CH ₂ CH ₂ O
  
  H
• ₃₄ ) _R = -O (̵ _CH 2 _CH 2O
  
  H m = _5-7
• 35) R = -NH-C (CH ₂ 0H) ₃
  

• 37) R = -NH- (CH ₂ ) ₃ -OCH ₂ CH ₂ 0CH ₂ CH ₂ -OC ₄ H ₉ -n
• 38) R = -NH- (CH ₂ ) ₃ -OC ₈ H ₁₇
• 39) R = -OCH ₂ CH (OH) CH ₂ -OC ₈ H ₁₇
• 40) R = -OCH ₂ CH ₂ OCH ₂ CH ₂ -OC ₄ H ₉ -n
• 41) R = -OCH ₂ CH ₂ OCH ₂ CH ₂ -OC ₂ H ₅
• 42) R = -OCH ₂ CH (OH) CH ₂ -OCH ₂ CH = CH ₂
• 43) R = -OCH ₂ CH (OH) CH ₂ -OC ₄ H ₉ -n

• 45) R = -OCH ₂ CH ₂ 0CH ₂ CH ₂ 0-46) R = -0 (̵ CH ₂ CH ₂ O
  
• ₄₇ ) _{R =} -O (̵ CH ₂ CH ₂ O
  
  m = _5-7
• 48) R = -OCH ₂ CH (OH) CH ₂ -O- (CH ₂ ) ₄ -O-CH ₂ CH (OH) CH ₂ O-
  

• 49) R = -O-CH ₂ CH ₂ -O-50) R = -0 (̵ CH ₂ CH ₂ 0) ̵ ₃
• ₅₁ ) _R = - _O (̵ _CH2CH 2 ₀ ) ̵ _m m = 5-7
  

• 52) R = -OCH ₂ CH ₂ 0CH ₂ CH ₂ OCH ₃
• 53) R = -0 (̵ CH ₂ CH ₂ O
  
  -H
• 54) R = -O (̵ CH ₂ CH ₂ 0
  
  C ₂ H ₅
• 55) R = -OCH ₂ CH (OH) CH ₂ 0H
• ₅₆ ) _R = -O (̵ _CH 2 _CH20
  
  H m = _8-10

• 57) R = -0 (̵ CH ₂ CH ₂ O
  
• 58) R = -0 (̵ CH ₂ CH ₂ O
  
• ₅₉ ) _R = -O (̵ _C H ₂ CH ₂₀
  
  m = ₈ -10
  

• 60) R = tert.C ₄ H ₉ R '= -0 (̵ CH ₂ CH ₂ O
  
  CH ₃
• 61) R = tert.C ₄ H ₉ R '= -0 (̵ CH ₂ CH ₂ O
  
  C ₂ H ₅ .
• 62) R = CH _s R '= -O (̵ CH ₂ CH ₂ O
  
  CH ₃

Mixtures of several compounds of the formula are often obtained in the preparation of these compounds. For example, the esterification of a diol can produce the monoester alongside the diester. Polyalkylene glycols are often technical mixtures with different degrees of oxyalkylation. If such diols are used, corresponding mixtures of compounds of the formula 1 are obtained. Such mixtures can be used for the use according to the invention as well as uniform compounds. Since such mixtures are mostly liquid, they can even be of particular advantage.

Examples of these are the compounds 8), 20), 21), 23), 28), 34), 47) and 51) listed above or mixtures of 3) and 24), of 19) and 29), of 33) and 46) or from 5), 26), 33) and 46).

worin R und R³ die eingangs gegebenen Bedeutungen haben.New compounds and as such also the subject of the invention are the compounds of formula II,

wherein R and R ^{3 have} the meanings given above.

Compared to the UV absorbers of the benzotriazole type proposed in Research Disclosure No. 24239, the benzotriazoles used according to the invention are distinguished by an increased hydrophilicity. However, it was not to be expected that hydrophilic UV absorbers would be particularly suitable as light stabilizers for inkjet printing recording materials. As is known, the effect of the UV absorbers consists in filtering out the short-wave light (200-400 nm) and this effect should only depend on the wavelength range of the light absorption of the molecule, but should be independent of other properties of the molecule. In this respect, the high effectiveness of the UV absorbers according to the invention was surprising. In addition, the compounds of formula I can be dispersed well. In combination with suitable surfactants, they produce very stable oil-in-water emulsions with a very small droplet diameter. Furthermore, it was found that such emulsions according to the invention do not agglomerate on drying, as a result of which the UV absorber is present on the recording material in a very homogeneous distribution, while corresponding emulsions or dispersions with the UV absorbers specified in Research Disclosure No. 24239 dry on to agglomerate the UV -Absorbers tend.

The recording material is a two-dimensional sheet which can consist of one or more layers. The carrier layer usually consists of paper or a plastic film or a laminate of such materials. The carrier layer can be coated on one or both sides with a material which is particularly receptive to the ink dyes. The recording material can be transparent, for example in the case of projection foils. In most cases, however, the recording material is not transparent and is read by the supervisor.

The UV absorber according to the invention can already be incorporated into the carrier material during the production thereof, for example in the production of paper by adding it to the paper pulp, or in the production of plastic films by adding it to the polymer before extrusion. A second method of application is spraying the carrier material with a solution of the UV absorber in a volatile solvent.

Usually, however, a dye-affine layer is applied to the carrier material and in this case the UV absorber according to the invention is added to the coating material. These coating compositions usually consist of a solid filler and a binder, as well as smaller proportions of additives.

The filler is the main quantitative component of the coating composition. Examples of common fillers are lime, chalk, silica, kaolin, talc, clay, calcium, magnesium or aluminum silicates, gypsum, barite, zeolite, bentonite, diatomaceous earth, vermiculite, titanium dioxide, zinc oxide, magnesium oxide, magnesium carbonate, starch or the surface-modified silica described in JP-A-85/260 377.

The binder binds the filler to itself and to the carrier material. It can be used as an aqueous solution, organic solution or aqueous dispersion. Examples of common binders are Polyvinyl alcohol, partially hydrolyzed polyvinyl acetate, cellulose ether, polyvinyl pyrrolidone and its copolymers, polyethylene oxide, salts of polyacrylic acid, sodium alginate, oxidized starch, gelatin, casein, vegetable rubber, dextrin, albumin, dispersions of polyacrylates or acrylate-methacrylate copolymers, latices of natural or synthetic rubber, poly (meth) acrylamide, polyvinyl ether, polyvinyl ester, copolymers of maleic acid, melamine resins, urea resins or chemically modified polyvinyl alcohols, as described in JP-A-86/134 290 or 86/134 291.

A dye receptor or mordant can be added to the binder, which fix the dye more firmly to the coating. Dye receptors for acid dyes are cationic or amphoteric in nature. Examples of cationic receptors are polymeric ammonium compounds such as e.g. Polyvinylbenzyl-trimethylammonium chloride, polydiallyl-dimethylammonium chloride, polymethacryloxyethyl-dimethyl-hydroxyethylammonium chloride, polyvinylbenzylmethylimidazolium chloride, polyvinylbenzyl-picolinium chloride or polyvinylbenzyl-tributylammonium chloride. Other examples are basic polymers such as Poly (dimethylaminoethyl methacrylate), polyalkylene polyamines and their condensation products with dicyandiamide, amine-epichlorohydrin polycondensates or those in JP-A-82/36 692, 82/64 591, 82/187 289, 82/191 084, 83/177 390 , 83/208 357, 84/20 696, 84/33 176, 84/96 987, 84/198 199, 85/49 990, 85/71 796, 85/72 785, 85/161 188, 85/187 582 , 85/189 481, 85/189 482, 86/14 979, 86/43 593, 86/57 379, 86/57 380, 86/58 788, 86/61 887, 86/63 477, 86/72 581 , 86/95 977, 86/134 291 or in US-A-4 547 405 and 4 554 181 as well as in the compounds described in DE-A-3 417 582. An example of amphoteric dye receptors is gelatin.

The dye-binding coating can contain a number of other additives, such as e.g. Antioxidants, light stabilizers (including UV absorbers that do not belong to the UV absorbers according to the invention), viscosity improvers, optical brighteners, biocides or / and antistatic agents.

Examples of suitable antioxidants are, in particular, sterically hindered phenols and hydroquinones, e.g. the antioxidants listed in GB-A-2 088 777, or JP-A-85/72 785, 85/72 786 and 85/71 796.

Examples of suitable light stabilizers are in particular organic nickel compounds and sterically hindered amines, such as e.g. those in JP-A-83/152 072, 86/146 591, 86/163 886, 85/72 785 and 86/146 591 or that in GB-A-2 088 777, JP-A-84/169 883 and 86/177 279 mentioned light stabilizers.

If the UV absorber used according to the invention is a liquid, these additives can be dissolved directly in the UV absorber. Or they are pre-dissolved in an organic solvent and mixed with the liquid UV absorber or with a solution of the UV absorber in an organic solvent. Aqueous coating compositions are preferably used. In this case, the UV absorber and the other additives must be dispersed as homogeneously as possible in the coating composition. If the UV absorber is liquid, it can be dispersed directly in the binder or in the coating composition after the addition of surface-active agents. If the UV absorber is solid or viscous, it is advisable to dissolve it in an organic solvent and to disperse this solution in the coating material. The solvent used is preferably a low-volatility solvent so that the UV absorber remains in the liquid state even after the recording material has been stored for a long time. To prepare the dispersions, however, a volatile auxiliary solvent is usually added, which is removed again during the production process of the recording material. Examples of low volatility solvents are organic liquids with an oily character and high boiling point, e.g. Phthalic acid esters (e.g. dimethyl, diethyl, dibutyl, diamyl, dihexyl, diheptyl, dioctyl, dinonyl or didecyl phthalate, or dibutyl chlorophthalate), glycolic acid esters (e.g. butyl phthalyl butyl glycolate), phenols (e.g. 2,4-di-n -amylphenol, 2,4-di-tert.amyiphenoi), phosphoric acid esters (e.g. diphenyl, triphenyl, tricresyl, cresyl diphenyl, dioctyl, dioctyl butyl, trioctyl, tridecyl, trixylenyl, tri ( isopropylphenyl), tributyl, trihexyl, trinonyl, trioleyl or tri (butoxyethyl) phosphate, citric acid esters (for example O-acetyl-triethyl-, -tributyl-, -trihexyl-, -trioctyl-, -trinonyl- or -tridecyl citrate), benzoic acid esters (e.g. butyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, tetradecyl, octadecyl or oleyl benzoate), esters of substituted benzoic acids (e.g. butyl 2-methoxybenzoate, pentyl-o-methylbenzoate, decyl-p-methylbenzoate, lauryl-o-chlorobenzoate, propyl-24, -dichlorobenzoate, oleyl-2,4-dichlorobenzoate or octyl-n-methoxybenzoate), fatty acid esters and dicarboxylic acid ureester (e.g. Hexadecyl myristate, dibutyl sebacate, dibutoxyethyl succinate, dioctyl adipate, dioctyl azelate, benzyl caprylate), esters of polyols (e.g. decamethylene glycol diacetate, triacetyl or tributyrene glycerol, pentaerythritol tetracapitate, naphosorbic acid, eg, isosorbic amide, eg, isosorbic amide, eg, isosorbic amide, eg, isosorbic amide or dicapryl amide, eg, isosorbic acid, dicapryl amide, eg, isosorbic acid, dicapryl amide, eg, isosorbic acid, eg, or Dimethyl, N, N-diethyl or N, N-dibutyllaurylamide), chlorinated paraffins, aliphatic or aliphatic-aromatic ethers (e.g. glycerol trialkyl ether, glycerol 1,3-dialkyl ether, n-pentadecylphenyl ether or 3-pentadecylphenyl ethyl ether) , Alkyl aryl carbamates (eg ethyl-N, N-diphenyl-carbamate) or mixtures of such liquids.

Liquids not boiling above 150 ° C can be used as volatile solvents. Examples of these are lower alkyl acetates or propionates (eg methyl, ethyl, n-propyl, isopropyl, butyl acetate, methyl or ethyl propionate), ethyl formate, diethyl carbonate, lower chloroalkanes (eg carbon tetrachloride, di- and trichlorethylene, 1,2-dichloropropane, chloroform or amyl chloride), ketones (e.g. acetone, methyl ethyl ketone, diethyl ketone or methyl isobutyl ketone), ethers (e.g. diisopropyl ether, dibutyl ether, tetrahydrofuran, dioxane), alcohols (e.g. methanol, ethanol, Isopropanol, butanol), monoethers of diols (e.g. ethylene glycol monomethyl ether or monoethyl ether), hydrocarbons (e.g. cyclohexane, methylcyclohexane, ligroin, benzene, toluene, xylene), nitromethane, acetonitrile, dimethyl sulfoxide, N-methylpyrrolidone, dimethylformamide, Tetrahydrothiophene dioxide, butyrolactone or 1,2-dimethoxyethane.

These auxiliary solvents serve to better disperse the UV absorber or its solution in high-boiling solvent. However, if the UV absorber is a liquid of low viscosity which can be dispersed well owing to its polar or hydrophilic character, no solvent is necessary, which is the case with many of the UV absorbers used according to the invention. This can simplify the preparation of the emulsions, and there is no need to recover the auxiliary solvent.

If an auxiliary solvent is used, it must be removed before the coating process. This can be done by heating and / or vacuum treatment, e.g. in a vacuum spray evaporator or a vacuum rotary evaporator.

If the binder of the coating composition is an aqueous solution, a dispersion or a latex, the oily phase of the UV absorber or its solution must be dispersed homogeneously in the aqueous phase and this dispersion should have a pot life as long as possible during which the dispersed Do not enlarge oil droplets or the dispersion segregates. This is possible - apart from the use of solvents - by using surface-active agents, by adding colloids to the aqueous phase and by correspondingly intensive mixing and dispersing machines. Examples of suitable dispersing machines are ultrasound devices, turbo stirrers, homogenizers, colloid mills, bead mills, sand mills or high-speed stirrers.

Examples of colloids which are added to the aqueous phase and stabilize the dispersions formed are polyvinyl alcohol, cellulose ether, polyethylene oxide, salts of polyacrylic acid, gelatin, vegetable gums, dextrin, casein or albumin. These colloids are also binders. Examples of surface-active dispersing aids can be nonionic, amphoteric, anionic or cationic surfactants. Examples of nonionic surfactants are esters or ethers of polyethylene oxides or polypropylene oxides or of their copolymers, fatty acid alkanolamides, ethoxylated alkanolamides, partial fatty acid esters of polyols (for example of glycerol, polyglycerol, sorbitol, pentaerythritol or sucrose), N-alkylmorpholines or long-chain amine oxides .

Examples of amphoteric surfactants are fatty acid amidoalkyl betaine, fatty acid amidoalkyl sultaine, fatty acid imidazoline betalne, N-alkyl-ß-aminopropionic acids or alkylene bis (amidoalkylglyclnate).

Examples of anionic surfactants are alkali or ammonium salts of fatty acids, of alkyl sulfates, of amido ethylene oxide sulfates, of alkyl or alkylaryl sulfonic acids, of N-alkyl and N-acyl-taurines, of fatty acid isethionates, of alkyl sulfosuccinates, of lignin sulfonates, of petroleum sulfonates, of mono- or dialkyl phosphates, of N-alkyl sarcosines, of alkyl sulfonamidoacetic acids, of alkyl lactates, of monoalkyl succinates, of fatty acid-protein condensation products, of (alkyl) naphthenic acids, of abietic acids, of sulfonated fatty acids or of N-acyl aminocarboxylic acids.

Examples of cationic surfactants are the quaternary ammonium salts of long-chain fatty amines and benzylamines, imidazolinium, pyridinium, picolinium or morpholinium salts with long-chain alkyl radicals, quaternary ammonium salts of long-chain alkylamidoalkylamines or bis-ammonium salts of quaternary diamines.

The surfactant can be pre-dissolved in the oil phase or in the water phase or in both phases. Different surfactants can also be added in both phases, but these must not have opposite activity (cationic-anionic).

In the case of the use of cationic surfactants, the oil-in-water dispersion can be destroyed when the filler is added if the surface of the filler has an electronegative charge, e.g. can be the case with silica. This problem can be solved by pretreating the surface of the filler. For this purpose, mostly silanes with functional groups are used that modify the surface's electrical charge accordingly, e.g. 3- (trimethoxysllyl) propyl-dimethyl-octadecyl-ammonium chloride.

• Diisobutyl-phenoxyethyl-dimethyl-benzyl-ammoniumchlorid, Didecyldimethyl-ammoniumchlorid, Talgfettammoniumacetat, Oleyl-dimethylbenzyl-ammoniumchlorid und Alkylarylsulfonate.

When using polyvinyl alcohol as a binder and colloid for the coating composition, the following surfactants have proven particularly useful as dispersing agents for the oily phase which contains the UV absorber:

• Diisobutylphenoxyethyldimethylbenzylammonium chloride, didecyldimethylammonium chloride, tallow fat ammonium acetate, oleyldimethylbenzylammonium chloride and alkylarylsulfonates.

The effect of the alkylarylsulfonates can be increased by adding wetting agents, which are also surfactants. Examples include sodium dloctyl sulfosuccinate and alkylnaphthalene sulfonates.

If the binder of the coating composition is applied as a solution in an organic solvent, the UV absorber and the other additives need not be dispersed. They are then added directly to the binder solution or previously dissolved in an organic solvent.

The coating composition is applied to the carrier, which is usually a paper, and dried by heating. The recording material thus prepared preferably contains 1 to 5000 mg / m ² , in particular 200-1200 mg / m ^{2, of} the UV absorber.

The recording material prepared in this way, which contains at least one of the UV absorbers according to the invention in its surface layer and which can contain the other additives mentioned, is likewise a subject of the invention. This recording material not only has a good absorption capacity for inkjet dyes, it also gives the printed dye a high light fastness. It does not matter what type of ink and the dye dissolved in it and what type of printer device is used.

In today's printers, a distinction is made between those with a continuous and intermittent ink jet. There are also drop-on-demand printers, bubble-jet printers, compound-jet printers or ion beam printers. The recording material according to the invention can be used for all of these apparatus methods.

The inks are mostly aqueous inks, but they can also be solutions of the dye in an organic solvent or in a molten wax. Aqueous inks usually contain highly water-soluble solvents, e.g. Mono-, di-, tri- or higher ethylene glycols, propylene glycol, 1,4-butanediol or ethers of such glycols, thiodiglycol, glycerol and its ethers and esters, polyglycerol, mono-, di- and triethanolamine, propanolamine, dimethylformamide, dimethyl sulfoxide, dimethylacetamide , N-methylpyrrolidone, 1,3-dimethylimidazolidone, methanol, ethanol, isopropanol, n-propanol, diacetone alcohol, acetone, methyl ethyl ketone or propylene carbonate.

Aqueous inks contain water-soluble dyes, which are also known for dyeing natural fibers. This can e.g. Monoazo, bisazo or polyazo or phthalocyanine dyes. Examples include Food Black 2, C.I. Direct Black 19, C.1. Sulfur Black 1, Acid Red 35, Acid Yellow 23 or copper phthalocyanines.

Aqueous inks can also contain various additives in smaller amounts, e.g. Binders, surfactants, biocides, corrosion inhibitors, sequestering agents, pH buffers or conductivity additives. They can also contain water-soluble UV absorbers or other water-soluble light stabilizers. In general, however, the addition of a UV absorber according to the invention to the recording material is sufficient.

If the ink is a non-aqueous ink, it represents a solution of the dye in an organic solvent or solvent mixture or in a molten wax. Examples of solvents used for this are alkyl carbitols, alkyl cellosolves, dialkylformamides, dialkylacetamides, alcohols, especially alcohols with 1 -4 C atoms, acetone, methyl ethyl ketone. Diethyl ketone, methyl isobutyl ketone, di-isopropyl ketone, dibutyl ketone, dioxane, ethyl butyrate, ethyl isovalerate, diethyl malonate, diethyl succinate, methyl pelargonate, butyl acetate, triethyl phosphate, ethyl glycol acetate, toluene, xylol. Examples of solid waxes as solvents are stearic or palmitic acid.

Such solvent-based inks contain soluble dyes therein, e.g. Solvent Red, Solvent Yellow, Solvent Orange, Solvent Blue, Solvent Green, Solvent Violet, Solvent Brown or Solvent Black. Such inks can also contain other additives as listed above for aqueous inks.

The following examples show the production of a coating composition used according to the invention and the recording material obtained therefrom. They also show the stabilizing effect of the addition of the UV absorber. Percentages refer to the weight unless otherwise stated.

For example:

Coating compositions based on silica / polyvinyl alcohol, containing a dispersion of a UV absorber - with and without the addition of tricresyl phosphate as an oily phase - are prepared. If tricresyl phosphate (TCP- is also used, this is added in the weight ratio UV absorber: TCP = 2: 1. The following solution of two anionic surfactants is used as the dispersant: 10 g phenylsulfonate HSR paste (65%), Hoechst AG 1 , 3 g of Nekass BX paste (62.5%), BASF AG, 13.7 water, 1.6 g of the surfactant solution are used per g of UV absorber and TCP.

UV absorber and possibly TCP are dissolved in a little ethyl acetate. A solution of 3.27 g polyvinyl alcohol (PVA) in 68 g water is mixed with the surfactant solution and this mixture is mixed with the ethyl acetate solution of the UV absorber using a magnetic stirrer. The mixing ratios can be seen in Table 1.

The ethyl acetate is removed in a rotary evaporator at 45 ° C., with a homogeneous dispersion of the oily phase in the PVA solution. 4.0 g of silica (type 244, Grace & Co) are added to each 3.27 g of PVA and the dispersion is homogenized with ultrasound for 30 seconds. The resulting coating composition is filtered through a sieve made of polyester fibers with a mesh size of 24 μm and the pH is adjusted to 7.0 by adding 2N sodium hydroxide solution. The coating mass (without UV absorber) contains 9.7% solids.

und ca. 43 %

The following UV absorbers are used: A-1 mixture of approx. 57%

and about 43%

The coating compositions are applied with a wire spiral to photographic paper in a thickness of 50 μm. The coating obtained after drying with warm air has about 5 g / m ² and contains 1 mmol of UV absorber per m ² . The recording material thus prepared is printed with a yellow and a red ink in an inkjet printing device. The yellow ink is prepared from 5 parts of Acid Yellow 23, 50 parts of diethylene glycol and 45 parts of water.

The red ink is prepared analogously using Acid Red 35. The inks are filtered through an ultrafilter with a pore size of 0.3 μm and filled into the ink cartridges of the "Think Jet" device (Hewlett-Packard). Test prints are prepared with a dot density of 75 dots per cm.

The color density (intensity) of the stained areas is determined using a densitometer (Macbeth TR 924) using a Status A filter. Then the sample prints are irradiated in an Atlas Weatherometer with a xenon lamp with an illuminance of 81 klux behind a window glass filter. The color density is then measured again. The percentage loss of color density during exposure is shown in Table 2.

Claims (16)

1. Use of compounds of the formula

where n is 1 to 4, R is hydrogen, C ₁ -C ₁₂ alkyl, C ₅ -C ₈ cycloalkyl, phenyl or C ₇ -C ₉ phenylalkyl, R ^{1 is} hydrogen, chlorine, Ci-C ₄ -alkyl or Ci-C4-alkoxy and in the case of n = 1 also means -COOR ³ and R ² a) in the case of n = 1 denotes a group -OR ³ or NR ⁴ R ⁵ , b) in the case of n = 2 a divalent group -OR ⁶ -O-, -OR ⁶ -N (R ⁷ ) -, -N (R ⁷ ) -R ⁸ -N (R ⁷ ) - or

means c) in the case of n = 3 a trivalent group

or -N (R ⁷ ) -R ⁸ -

-R ⁸ -N (R ⁷ ) -means and d) in the case of n = 4 a tetravalent group

or -N (R ⁷ ) -R8-

-R ^{8 '} -

-R ⁸ -N (R ⁷ ) - means where R ^{3 is} hydrogen, C ₁ -C ₁₈ alkyl substituted by one or more -OH or -O-COR ¹⁰ , by one or a plurality of -0- or -N (R ⁷ ) -interrupted C ₃ -C ₃₀ -alkyl which may be substituted by one or more groups -OH or -O-COR ¹⁰ , unsubstituted or -OH-substituted C ₅ -C ₁₂ -Cycloalkyl, unsubstituted or -OH-substituted C ₂ -C ₁₈ alkenyl, C7-cis-phenylalkyl or alkylphenylalkyl, glycidyl, furfuryl or a glycosyl group, R ⁴ and R ⁵ independently of one another are hydrogen, C ₁ -C ₁₈ alkyl , Ci-C ₄ -Hydoxyalkyl, interrupted by -0- or -N (R ⁷ ) - C ₃ -C ₁₈ alkyl, C ₅ -C ₁₂ cycloalkyl, unsubstituted or by hydroxyl, Ci-C ₄ alkyl, Ci -C ₄ alkoxy or halogen substituted phenyl, C ₃ -C ₈ alkenyl, C ₇ -C ₁₅ phenylalkyl or alkylphenylalkyl or R ⁴ and R ⁵ together with the N atom represent a pyrrolidine, piperidine or piperazine or form a morpholine ring, R ⁶ C ₂ -Cs alkylene, C ₄ -Cs alkenylene, C ₄ alkynylene, cyclohexylene, by one or more -O- or -N (R ⁷ ) -interrupted C ₄ -C _3o alkylene or a group - CH ₂ -CH (OH) -CH ₂ -OR ⁹ -O-CH ₂ -CH (OH) -CH ₂ - or

means R ^{7 means} hydrogen or C ₁ -C ₁₈ alkyl, R ^{8 is} C ₂ -C ₁₂ alkylene, which can be interrupted by one or more -0- R ⁹ C ₂ -C ₈ alkylene, interrupted by one or more -0- C ₄ -Cio alkylene, cyclohexylene, phenylene or a group

means R ^{10 is} C ₁ -C ₁₈ alkyl or phenyl, R ^{11 is} C ₃ -C ₁₀ alkanetriyl and R ^{12 is} C ₄ -C ₁₂ alkane tetrayl, as light stabilizers for recording materials for inkjet printing. 2. Use according to claim 1 of compounds of the formula wherein n is 1 or 2, R is C ¹ -C ₄ -alkyl, R ^{1 is} hydrogen, chlorine or methoxy, R ² a) in the case of n = 1, a group -OR ³ or -NR ⁴ R ⁵ means, b) in the case of n = 2 is a group -OR ⁶ -O-, where R ^{3 is} hydrogen, C ₁ -C ₁₈ -alkyl substituted by 1 to 3 OH groups, by one or more -0- interrupted C ₃ - C ₁₈ alkyl, which can be substituted by one or more -OH, means cyclohexyl or allyl, R ⁴ and R ⁵ independently of one another Ci-C1 ₂ alkyl, C ₂ -C ₄ hydroxyalkyl or C ₃ -C ₁₂ alkoxyalkyl mean or R ⁴ and R ⁵ together with the N atom form a pyrrolidine, piperidine, piperazine or morpholine ring, R ⁶ C ₂ -C ₆ alkylene, by one or more -O- interrupted C ₄ -C ₁₄ alkylene or a group -CH ₂ -CH (OH) -CH ₂ -OR ^9- O-CH ₂ -CH ( OH) -CH ₂ means, and R ^{9 is} C ₂ -C ₄ alkylene or C ₄ -Cs alkylene interrupted by -O-. 3. Use according to claim 1 of compounds of formula I, wherein R is tert-butyl. 4. Use according to claim 1 of compounds of formula I, wherein n is 1 or 2 and R ^{2 is} a group -OR ³ or -OR ⁶ -O-. 5. Use according to claim 1 of compounds of the formula I in which n is 1 or 2, R ^{1 is} hydrogen, chlorine or methoxy, R ² a) in the case of n = 1, a group of the formula -O- (̵CH ₂ CH ₂ O

-H,

or

means where u is 1-9, v 1-6 and w 1-6. b) in the case of n = 2, a group of the formula -O (̵ CH ₂ CH ₂ O

or

means where x is 1-7 and y is 1-4. 6. Use according to claim 1 of compounds of the formula wherein n = 1, R ^{1 is} -COOR ³ and _R 2 is -OR ³ . 7. Use according to claim 1 of compounds of formula I which are liquid at room temperature. 8. Stabilized against light damage recording material for inkjet printing, consisting of a two-dimensional sheet with an inkjet printable surface, characterized in that the printable surface contains at least one compound of formula I according to claim 1. 9. Recording material according to claim 8, characterized in that the fabric is a coated paper. 10. Recording material according to claim 8, characterized in that the printable surface contains a cationic dye acceptor in addition to the compound of the formula. 11. Recording material according to claim 8, characterized in that the printable surface contains, in addition to the compound of the formula I, an antioxidant, a further loan protective agent, an optical brightener and / or a biocide. 12. A method for producing a recording material stabilized against light damage for inkjet printing, characterized in that a two-dimensional support is coated with a coating composition which contains at least one compound of the formula 1 according to claim 1. 13. The method according to claim 12, characterized in that the coating composition contains an aqueous binder and that the compound of formula I is dispersed homogeneously in the aqueous phase of the coating composition as an oil phase, it being possible for the compound of formula I to be dissolved in an oily liquid. 14. The method according to claim 12, characterized in that a surfactant is added to the aqueous or the oily phase. 15. Compound of the formula II,

wherein R and R ^{3 have} the meaning given in claim 1. 16. A compound according to claim 15 of formula II, wherein R is tert-butyl.