DE1444014C - - Google Patents

Description

It is already known to use derivatives of benzoxazole as optical brightening agents. So is z. B. in the German patent 1 040 555 a process for the preparation of a, / 3-di [benzoxazolyl- (2)] ethylene described, which are useful for lightening synthetic fibers, e.g. B. those made from cellulose esters, in particular cellulose acetate, made of polyacrylonitrile, polyesters, such as polyethylene glycol terephthalate, or polyvinyl chloride, are suitable.

It has now been found that colorless or almost colorless, fluorescent benzoxazole compounds, that of the general formula

CH = CH - (~ J

COOR

20th

can be used as an optical brightening agent. In formula I, the radicals R can be a hydrogen atom, an alkyl, cycloalkyl, haloalkyl, hydroxyalkyl, alkoxyalkyl, a Ν, Ν-dialkylaminoalkyl group or a corresponding quaternary trialkylammonium alkyl group, an aryl or aralkyl group, the radicals R ₁ and R ₂ denote an alkyl, alkoxy or aryl group, a halogen atom or together a fused aromatic or hydroaromatic ring, and R _{1 can} also denote a hydrogen atom.

The benzoxazoles of the general formula to be used as lightening agents according to the invention I can be prepared in various ways, for example by reacting substituted o-aminophenols or o-aminonaphthols with the acid chlorides of 2-, 3- or 4-carboalkoxycinnamic acids and then heating the obtained N-acyl compounds in an inert gas atmosphere in high-boiling solvents, optionally in the presence of catalysts, such as Zinc chloride, the oxazole ring being closed with elimination of water. Furthermore, the transesterification of 2- (carbomethoxy-styryl) -benzoxazoles with higher boiling alcohols possible. Also can the 2- (cyano-styryl) -benzoxazoles with alcohols and hydrogen chloride into the 2- (carboalkoxystyryl) -benzoxazoles being transformed. The conversion of the acid chlorides of 2- (carboxystyryl) -benzoxazoles also leads with compounds containing an alcoholic or phenolic hydroxyl group, to compounds of the general formula I.

As o-aminophenols or o-aminonaphthols are named for example:

4-amino-3-hydroxy-toluene,
5-amino-4-hydroxy-1,2-xylene,
5,6,7,8-tetrahydro-3-amino-2-naphthol,
5-Amino-6-hydroxyhydrindene and
o-chloro ^ -amino-S-hydroxy-toluene.

As alcoholic or phenolic compounds that are used to esterify 2- (carboxy-styryl) -benzoxazoles can be used, be z. B. called: monovalent and polyvalent aliphatic, cycloaliphatic

60 or araliphatic alcohols, phenols, naphthols, such as methanol, ethanol, n-propanol, isopropanol, n-butanol, tert-butanol, octanol, cyclohexanol, 2-, 3-, 4-methylcyclohexanol, 2-chloroethanol - (1) ,

1 - chloropropanol - (2), glycol, propanediol - (1,2), n-butanediol- (l, 3) and - (1,4), 2 - methyl - η - butanediol- (l, 3), n-hexanediol (2.5), glycerine, pentaerythritol, diethylene glycol, triethylene glycol, glycol monomethyl ether, Glycol monoethyl ether, glycol monon butyl ether, 3 - methoxy - η - butanol - (1), glycid, Phenol, o-, m- and p-cresols, xylenols, benzyl alcohol,

2 - penyl - ethanol - (1), 4 - isopropyl - benzyl alcohol, 2 - dimethylamino - ethanol - (1), 2 - diethylaminoethanol- (l), 2-di-n-butylamino-ethanol- (l), 1-dimethylamino-propanol- (2).

The compounds are characterized by excellent fluorescence properties and very good lightfastness when lightening fiber material, especially made of polyesters of the polyethylene glycol terephthalate type, Polyamide, acetylated cellulose and polyacrylonitrile. To be used according to the invention Lightening agents can be used in a manner known per se, either in the form of solutions in water or in organic solvents or in the form of dispersions, optionally under Use of dispersants.

The required quantities, which can fluctuate within wide limits, can be determined through preliminary tests easily determine. The compounds can also be used together with chemical bleaching agents, e.g. B. oxidative or reductive ones, such as sodium chlorite, sodium dithionite, sodium borohydride, can be used.

Furthermore, these compounds can be used in commercial detergents to beautify the items to be washed be added, with good lightening effects even at washing temperatures below the boiling point Polyester fibers can be achieved.

Furthermore, they can also be added to spinning or casting compounds for the production of artificial Fibers, threads, films or other structures are used. The following examples are intended to demonstrate the versatility of the application show without, however, being restricted to it.

example 1

A bleached in a conventional manner with sodium chlorite tissue from Polyäthylenglykolterephthalatfäden, which still has a slight yellow tinge is ^l / treated for ₂ hour in an aqueous liquor at 95 to 98 ° C, the 0.3% of the compound (II)

N (II)

CH = CH - / V COOCH,

contains in dispersed form. The fabric then shows an excellent shade of white, which also after 100 hours of exposure to a xenon high-pressure lamp is not noticeably weakened. On The bodies listed in the following table can also be used in place of the compound II.

Constitution melting point, ⁰ C

H ₃ CH ₃ C

H ₃ CH ₃ C

H ₃ CH ₃ C

H ₃ CH ₃ C

L,

CH = CH - <V-COO-CH ₇ -CH,

COO - CH, - CH, - CH,

CH = CH-COO CH, CH, CH, CH ₁

CH-

CH = CH

COO

Cl-T> N

H ₃ CH ₃ C

H ₃ CH ₃ C

= CH - ^ -> - COO-CH ₂ -CH ₂ -O-CH ₂ -CH ₃

COOCH ₃

CH = CH- / V-COO-CH ₂ -C ₆ H ₅

= CH- / V-COOCH ₃

= CH- / V-COOCH ₃

H ₃ CH ₃ C

CH = CH-

CH ₃

COOC-CH ₃ CH ₃ 165 to 167

148.5 to 150.5

118.5 to 121

160 to 162

208 to 210

116 to 117.5

219 to 220

179 to 181

161 to 163

191 to 192

136 to 138

continuation

constitution

Melting point, C.

COO-.CH, -CH, -Cl

175.5 to 178

COO - CH, - CH, - OH

176 to 176.5

163.5 to 165.5

COOCH,

COOCH, CH ₃

V 11 θ '

^> - CO- CH ₂ CH ₂ - N - CH ₃

152.5 to 154

189 to 191

CH,

Decomposition at
251 to 254

OSO ₃ CH ₃

The above compounds are also stable in the chlorite bleach bath and give good results Lightening effects.

The above-mentioned 2- (4'-Carbomethoxystyryl (-5,6-dimethyl-benzoxazole (II) can be prepared in the following manner: To a 60 ⁰ C hot mixture of 13.7 parts by weight of 5-amino-4-hydroxy-l , 2-dimethylbenzene, 18 parts by weight of N ₅ N-dimethyl-aniline and 100 parts by volume of chlorobenzene are added slowly with stirring, a 50 ⁰ C. solution of 22.5 parts by weight of 4-carbomethoxy-cinnamic acid chloride in 100 parts by volume of chlorobenzene and stirred for 2 hours at 60 to 65 ° C. After cooling, the reaction product which has precipitated out at 5 ° C. is filtered off with suction and treated with steam until all adhering chlorobenzene and dimethylaniline have evaporated. After suction and drying, 28 parts by weight of the 4-carbomethoxycinnamic acid amide of S. -Amino ^ -hydroxy-l ^ -dimethylbenzene from melting point 231 to 232 ° C (with decomposition).

To convert the benzoxazole derivative, the dried carboxamide (28 parts by weight) in a flask provided with a gas inlet tube and descending condenser while passing through Nitrogen together with 50 parts by volume of distilled trichlorobenzene and in the presence of 0.2 parts by weight of molten zinc chloride in an oil bath for 1 hour heated to 210 ° C. The melt which crystallizes on cooling becomes at 60 ° C with 50 parts by volume of ethanol added, the mixture cooled to 5 ° C and filtered off with suction. 25 parts by weight of 2- (4'-carbomethoxystyryl) -5,6-dimethylbenzoxazole are obtained, which is purified by recrystallization from dioxane and ethyl acetate with the addition of animal charcoal. Melting point 200 to 201 ° C.

The compound II can also be prepared in the following way: To a suspension of 10.0 parts by weight of 2- (4'-cyano-styryl) -5,6-dimethyl-benzoxazole (m.p. 198-200 ⁰ C) in 100 parts by volume of methanol Introduced 5 hours of hydrogen chloride gas. When the reaction mixture cools, 8 parts by weight of 2- (4'-carbomethoxystyryl) -5,6-dimethyl-benzoxazole separate out, which after dissolving has a melting point of 199 to 200 ° C. - (4'-Carbomethoxy-styryl) -5,6-dimethy.lbenzoxazols is identical.

The transesterification of the compounds listed in the table also presents no difficulties. So z. B. the listed 2- (4'-carbobutoxystyryl) -5,6-dimethyl-benzoxazole in the following way

I <4 '4' 4- U i H:

will hold: 20 parts by weight of the above-mentioned 2- (4'-carbomethoxy-styryl) -5,6-dimethyl-benzoxazole are in 500 parts by volume of n-butanol in the presence of 10 parts of sodium butoxide for 6 hours Refluxed. On cooling, 13 parts by weight of 2- (4'-carbo-n-butoxy-styryl) -5,6-dimethyl-benzoxazole crystallize out. Recrystallization from cyclohexane or ethyl acetate is obtained Needles with a melting point of 118.5 to 121 ° C.

Example 2

A gray fabric of Polyäthylenglykolterephthalatfäden is a liquor ratio of 1: ¹ for 20 J ₂ hours C-bleached at 80 to 85 ° C and further ₂ hours at 98 V ^0th

The bleaching liquor, which has a pH of 3.5, contains 0.15 g / l of the following in dispersed form Compound (III)

CH = CH-

- COO - CH ₂ - CH ₂ - CH ₃

(III)

and 0.5 g / l sodium chlorite (100%). The white shade of the fabric treated in this way is brilliantly clear.

Example 3

. A conventionally bleached fabric made of polyethylene glycol terephthalate is with a aqueous dispersion of 5 g / l of compound II impregnated and squeezed off on a padder so that that the fabric still contains 60% of its weight in dispersion. After that, the fabric is at 190 ° C treated with hot air for 60 seconds. After this treatment it shows a nice, even Shade of white.

Example 4

A detergent with the following composition:

12% alkyl aryl sulfonate,
6% oleylamine octaglycol ether,
4% potassium pyrophosphate,
8% sodium p-toluenesulfonic acid
become 0.5% of the compound below

COO - CH ₂ - CH ₃

(IV)

added.

A grayed polyester fabric is washed for 10 minutes at 80 ° C with a liquor containing 3 g / l of this Contains detergent. It then had a beautiful, appealing shade of white. Even after 10 washes no undesirable color shift was found of this type.

The 2- (4'-carbethoxy-styryl) -5,6-dimethyl-benzoxazole (IV) can be prepared as follows:

Of 2- (4'-carboxy-styryl) -5,6-dimethylbenzoxazols (light yellow crystals from toluene the melting point: 223-224 ⁰ C) to a suspension of 31.2 .Gewichtsteilen of the acid chloride in dry dioxane are added at 150 parts by volume of Room temperature with stirring dissolves 2.3 parts by weight of sodium metal in 50 parts by volume of ethanol. The mixture is heated to 50 ° C. for 4 hours and then the ethyl ester formed is precipitated with water.

55

29.2 parts by weight of compound IV are obtained. After four recrystallization from ethyl acetate With the help of animal charcoal, the melting point is 165 to 167 ° C.

B e i s ρ i e 1 5

A raw fabric of a copolymer, consisting of at least 85% polyacrylonitrile, is used in a pH 3.5 for 30 minutes at 80 to 85 ° C with a liquor containing

1.2% sodium chlorite (100%),
1.0% bleaching agent (consisting of 32% 01-acid methyl tauride, 60% ammonium sulfate and 8% sodium pyrophosphate),
0.2% acetic acid (100%),
1.2% sulfuric acid (1:10),

bleached and treated further at 98 ° C. for _{2 hours.} The bleaching liquor contains 0.2% (added in the form of an aqueous dispersion) of the compound VI

= CH - ^< \ ~ \ - COO - CH ₂ - CH ₂ -

(VI)

CH ₂ - CH,

(Melting point 132 to 134 ° C)

The fabric treated in this way shows an excellent whiteness which is evident even after exposure for 120 hours practically unchanged with a xenon high pressure lamp.

209 645/42

9 10

The following connection can also be used in place of connection VI:

H, C

CH = CH-

The abovementioned compound VII can be prepared in the following manner: To a 70 ° C. solution of the acid chloride made from 32.5 parts by weight of 2- (4'-carboxy-styryl) -5,6-dimethy lbenzoxazole in 330 parts by volume of chlorobenzene is added Stir 13 parts by volume of 2-dimethylamino-ethanol. After 2 hours of heating in a water bath, the product is filtered off with suction, treated at 50 ° C. with a solution of 15 parts by weight of potassium hydrogen carbonate in 200 parts by volume of water and treated with COO-CH ₂ -CH ₂ -N

CH ₃

CH ₃

(VII)

CH = CH

rewashed. After drying, 27 parts by weight of the ß-dimethylamino-ethyl ester are obtained general formula VII. The melting point after recrystallization is 138 to 139 ° C.

Example 6

A copolymer bleached in the usual way fabric, consisting of at least 85% polyacrylonitrile, is in a liquor ratio of 1:20 with 0.06 g / l an aqueous solution of compound VIII

(VIII)

COO - CH ₂ - CH ₂ - N - CH

δ-SO ₂

(Melting point 271 to 274 ° C)

V treated at 98 ° C. for _{2 hours.} The fabric then shows a brilliant white tint that cannot be achieved without the use of an optical brightener.

In the same way, instead of the compound VIII, the benzoxazole mentioned below of the general Formula DC can be used:

CH ₃
COO - CH ₂ - CH ₂ - "W-CH ₃

CH,

δ —so, —o- (DC)

CH,

The quaternary ammonium salt of the general formula DC can be prepared as follows: A mixture of 8 parts by weight of compound VII, 40 parts by volume of methanol and 2.8 parts by volume Dimethyl sulfate is refluxed for 1 hour. Receives after vacuuming in the cold 10 parts by weight of the quaternary ammonium salt with a melting point of 243 to 245 ° C.

B e i s ρ i e 1 7

A fabric bleached in the usual way, consisting of 50% vinylidenecyanide and 50% vinyl acetate, is used in a liquor ratio of 1:20 with a liquor consisting of

10 g / l phthalic acid dimethyl ester,
2 g / l alkylaryl polyglycol ether sulfate,
0.1 g / l of the compound DC,

Treated at 98 ° C for 30 minutes. The white measurement carried out at a wavelength of 460 ηΐμ gives a value of 91.0%, based on magnesium oxide as standard = 100%. (The not lightened Fabric shows a value of 83.)

Claims (1)

Claim: Use of colorless or almost colorless, fluorescent benzoxazole compounds the general formula CH = CH C = O 60 65 OR in which the radical R is a hydrogen atom, an alkyl, cycloalkyl, haloalkyl, hydroxyalkyl, alkoxyalkyl, a Ν, Ν-dialkylaminoalkyl, a trialkylammoniumalkyl, an aryl or aralkyl group, the radicals R ₁ and R ₂ , denote an alkyl, alkoxy, aryl group, a halogen atom or together a fused aromatic or hydroaromatic ring, where R _{1 can} also denote a hydrogen atom, as "optical brightening agents.