DE1302052B - Optical brighteners - Google Patents

Description

British Patent 824,659 discloses 1,4-bis (2'-benzoxazolyl) benzenes mentioned, which are said to be suitable as optical brightening agents. These connections However, they only have a very low fluorescence capacity and are mainly used as spinning brighteners unusable.

The subject of the main patent 1 282 592 is the use of yellow, reddish in solution greenish blue fluorescent benzoxazole compounds of the general formula

in which the radicals Ri and R-i are a hydrogen atom, an alkyl or aryl group, a halogen atom or together a fused hydroaromatic Ring mean as an optical brightening agent. According to the first additional patent application 1 301 791 the products can also be used for the optical brightening of polyacetals.

In a further embodiment of the main patent 1 282 592 it has now been found that yellowish to yellow benzoxazole compounds of the general type, fluorescing reddish to greenish blue in solution formula

- C

-N

, R ₃

(I)

25th

in which the radicals Ri to Ri are a hydrogen atom or a low molecular weight alkyl group containing up to 4 carbon atoms and in which the two benzoxazolyl radicals are differently substituted, can also be used as optical brighteners.

The compounds mentioned above are particularly suitable as lightening agents for threads and foils, in which case the lightening agent is also used to produce the high molecular weight Substance serving starting materials can be added.

The benzoxazoles of the general formula to be used as lightening agents according to the invention (I) can be prepared in a number of ways, for example by adding 4- [benzoxazolyl- (2 ')] -naphthoic acid- (l) of the formula H-,

HO

(HIa)

condensed and the resulting N-acyl compounds of the formula

- CO -NH

HO Vr ₄

(IV)

in an inert gas atmosphere, advantageously nitrogen, in high-boiling solvents, preferably 1,2,4-trichlorobenzene or in mixtures of trichlorobenzenes, heated to an internal temperature of more than 200 ° C., preferably 215 to 220 ° C., optionally in the presence of catalysts such as zinc chloride and the o-aminophenols (III) are selected so that in the 1,4- [bis-benzoxazolyl- (2 ')] -naphthalene compounds (I) at least one of the radicals R ₁ . Ri. R ₁ or R \ represents a symbol which deviates from the meaning of the other substituents.

The following can be used, for example, as o-aminophenols of the formula (III): o-aminophenol. 3 - amino - 4 - hydroxy - 1 - diethylbenzene. 3 - amino-2 - hydroxy - 1 - methylbenzene, 4 - amino - 3 - hydroxy - 1 - methylbenzene. 5 - amino - 4 - hydroxy-1,2 - dimethylbenzene. 5 - amino - 4 - hydroxy -1.3 - dimethylbenzene, 3 - amino - 4 - hydroxy - 1 - tert. butylbenzene.

The 4- [Benzoxazoiyl- (2 ')] - naphthoesäuren- (l) (II) can by reaction of o-aminophenols general formula (III a) with acid chlorides of 4-carboalkoxy-naphthoic acids (1) of the general

formula

HOOC - - X

IV)

(X = COOR, where R is a low molecular weight, up to Alkyl group containing 4 carbon atoms) or with the acid chloride of 4-cyannaphthoic acid- (l) (V, X = CN) can be obtained by converting the N-acyl compounds obtained from formula

R,

NH

OH

CO

(VI)

Ri

- COOH (II)

after conversion into uie acid chlorides with o-aminophenols the formula

H, N

HO

(III)

R.

expediently in an inert gas atmosphere in high-boiling solvents, preferably 1,2,4-trichlorobenzene or in mixtures of trichlorobenzenes. optionally in the presence of catalysts such as zinc chloride, heated and * the under Elimination of water formed 4- [Benzoxa / oI-vl- <2Tj ~ iiaphilK? Esaure- (l) -emer

CiS

X (VH)

(X = COOR) or the 4- [benzoxazolyl- (2 ')] -naphthoe- (1) -nitriles (X = CN) in a manner known per se saponified to the free acids. The elimination of water from the N-acyl compounds of the general formula (VI) is advantageously carried out at temperatures above 200 C., preferably 215 to 220 C.

Another process for the preparation of 4- [benzoxazolyl- (2 ')] -naphthoic acid- (l) (II) consists in the condensation of 1 mole of the dichloride of naphthalene-diacid- (1,4) (VIII) with 1 mole the _{) 0} o-aminophenoie (III a) in the presence of acid-binding agents, e.g. B. tertiary amines such as dimethylaniline. to the N-acyl compounds (IX)

R,

HOOC

NH

OH

/ - COOH

(VIII)

CO

- coci

(IX)

after saponification of the acid chloride residue by heating in an inert gas atmosphere, advantageous Nitrogen, in high-boiling solvents, e.g. B. 1.2.4-TrichIorbenzol, on internal temperatures of above 200 C. preferably 215 to 220 C. optionally in the presence of zinc chloride, in the corresponding 4 - [Benzoxazolyl - (2)] - naphthioic acid- (l) (II) can be transformed.

The abovementioned can be used as ο-aminophenol dissolution components (III a).

As 4-carbalkoxy-naphthoic acids (1) (V, X = COOR) the following may be mentioned: 4-carbomethoxynaphthoic acid - (D. 4 - carboethoxy - naphthoic acid - (i). 4 - carbopropoxy - naphthoic acid - (1), 4 - Carbi-opropoxy-naphthoic acid- (1), 4-Carbobu w> \\ -na; > h thoesäui e- (1). 4-Carbisobuto. \ Y-naphthoesäi: re (1).

These half esters can by saponification of the corresponding Naphthalene-1.4-dicurbonsäurediestei with one equivalent of an alkali or alkaline earth metal hydroxide can be prepared in a simple manner.

The acid chlorides of 4-CarbaIkox \ -naphthoesäuren- (l) (V. X = COOR) can be used in a manner known per se, for. B. Civaxh reaction of 4-carbalkoxy-naphlhoesäuren- (l) with thionyl chloride, can be obtained.

The reaction of the o-aminophenols (III a) with the acid chlorides of 4-carbalkoxy-naphthoic acids (I) and 4-C'yannaplUhoes: iure- (1) is advantageous in an organic; Solvents, e.g. B. toluene or chlorobenzene, in the presence of a terlia'ren base to bind the split off hydrochloric acid, 7. B. Dimethylanüin. at an elevated temperature, preferably from about 50 to 100.degree. When the reaction mixture * cools, the acylamino compound (VI) crystallizes out, is filtered off with suction and freed from adhering solvent by steam distillation.

The N-acyl compounds (VI) are converted into the benzoxazoles (VII) in high-boiling solvents carried out. As such, f> 5 is suitable especially 1,2,4-trichlorobenzene or a mixture from Ti'chlorbenzoien. The internal temperature of the reaction mixture should be above 2 (K) C, preferably at 215 to 220 C. Can be used as catalysts one compounds such as zinc chloride or p-toluenesulfonic acid use.

The compounds of the general formula (I) are distinguished by excellent fluorescence properties and very good lightfastness when lightening fiber materials. Film. Foils, tapes and other molded articles made of synthetic material. Examples of synthetic materials are called: linear polyesters of the polyethylene glycol terephthalate type: Polyamides of the polycaprolactam or nylon type; also polymerization products made of vinyl chloride. Vinylidene chloride and their copolymers, which another a small amount of substances which can be copolymerized with vinyl chloride or vinylidene chloride are incorporated into the polymer contain; Polymerization products of the polyethylene or polypropylene type; Homo- or copolymers from trioxane and cyclic ethers, such as ethylene oxide and propylene oxide. Oxacyclobutanes, glycol formals. Diglycol formals. but especially those with ethylene oxide.

The brightening agents can be used during the manufacturing process of the materials to be refined bring to application by z. B. a melt of polyethylene glycol terephthalate, which is intended for the production of fibers or films, or another spinning mass, e.g. B. such of a linear, synthetic polyamide. The compounds of the formula (I) can also before or during the polycondensation, e.g. B. to polyester or polyamide, or before or during the Polymerization can be added to the monomers.

If necessary, textile and non-textile structures can be made from the synthetic materials mentioned even after their deformation with the compounds of the formula (I) at elevated temperatures Lighten optically For this purpose, these substances are either in a known manner in In the form of aqueous dispersions, optionally with the aid of dispersants or in In the form of solutions in organic solvents. The compounds can lighten up textile materials are also used together with oxidative or reductive chemical bleaching agents are also used in the commercial detergents to beautify the Items to be washed are possible, with a high degree of whiteness even at temperatures below the boiling point be achieved.

The optimal use quantities, which can vary within wide limits (0.001 to 2 ° ₍₁ , preferably 0.01 to 0.5 '\ i, based on the weight of the goods), depend on the substrate and the whitening process Easily determine preliminary tests.

The new brightening agents are the 1,4-bis- (2-benzoxazolyl) -benzenes known from British patent specification 824,659 Far superior in terms of fluorescence power and \ above all in terms of spinning brightening.

The following examples are intended to demonstrate the wide range of possible applications point out.

example 1

1 kg of polyethylene glycol terephthalate chips matted with titanium dioxide (SV = 8 (K)) with a solution of 0.5 g of compound XII (table) in Sprayed 100 ml of methyl acetate, dried

5 6

and mixed. The chips prepared in this way become parts of crude half-ester, which can be purified from 1000 parts by weight of toluene by recrystallization in a spinning head provided with an inserted spinning head. Extruder at a spinning temperature of 285 ° C. The naphthalene filaments which crystallize out of the filtrate are spun: 1,4-dicarboxylic acid monomethyl ester is ^{sufficiently pure after the nozzle 24 0.25 mm s} drying and melts at 150.5 to

Deduction lOOOm-Min. ¹⁵ |. ^C " ^kla r · ...,, .. ....

. ςη "λΐ parts by weight of the naphthalene thus obtained

- ^u * - ⁴ j 4 _ ^ carboxylic acid - monomethyl ester are in

87 parts by weight of toluene with 16.4 parts by weight

The threads obtained are reacted at 150.degree. C. around the thionyl chloride at 80.degree. After removal 3.65 times their length stretched. They show that of the excess thionyl chloride is left the same technological properties, but a still warm solution of the acid chloride to one significantly higher degree of whiteness than threads produced without a brightening 75 C preheated mixture of 11.2 weight average. share o-aminophenol. 12.7 parts by weight of dimethyl die Compound XII can be added dropwise to aniline and 70 parts by weight of toluene in the following manner are made: stir at 75 ° C. for a further 3 hours. The excellent

34.7 parts by weight of 4- [benzoxazolyl- (2 ')] -naphthoe-precipitated acylamino compound is filtered off and acid- (1) are washed in 220 parts by weight of chlorobenzene with cyclohexane and methanol or by adding 19.6 parts by weight of thionyl chloride to the acid steam distillation of the adhering Solution chloride transferred. After the thio agent has been distilled off, freed. To close the ring, the excess genyl chloride is heated, the solution of the dried acylamino compound with 72 parts by weight of acid chloride to form an 80 ° C. suspension of parts 1,2,4-trichlorobenzene and 0.1 part by weight of zinc-20.5 parts by weight of 3-amino-4-hydroxy-tert. butyl chloride in a nitrogen atmosphere for about 2 hours of benzene (98%) in 190 parts by weight of chlorobenzene at 215 to 220 C (internal temperature). While cooling and 15.3 parts by weight of dimethylaniline are added dropwise, 48 parts by weight of methanol are added and stirring is continued for 2 ^! 2 hours at 80 C. The out to. The acylamino compound which has crystallized out, the acylamino compound which has precipitated is filtered off with suction at 50 ° C. and twice with 25 parts by weight of Cyclo and washed from anhexane by steam distillation and dried. After the adhering solvent freed. After drying, crystallization from toluene with the addition of active ingredient gives 48 parts by weight of melting point 257 carbon, giving pure 4- [BenzoxazoIyI- (2)] - up to 259 ° C. (with decomposition). 1-naphthoic acid methyl ester, melting point 160

48 parts by weight of the acylamino compounds obtained up to 161 C.

dung be washed with 0.15 parts by weight of anhydrous 111 parts by weight of as described above, zinc chloride is mixed and 4- obtained in nitrogen atmosphere [benzoxazolyl (2 ')] - l-naphthoesäurein 145 parts by weight of 1,2,4-trichlorobenzene l ³ j STUN .15 methylesters are in 1430 Parts by weight of ethanol heated to 215 to 220 C internal temperature. (96 " ₍ > ig) suspended. At 80 ° C., while cooling, a solution of 25 parts by weight of potassium-methanol is added while stirring Methanol is heated thoroughly and the mixture is washed under reflux for 2 hours. After drying, a cooling of 4 ° is obtained. 650 parts by weight of ethanol are then 43 parts by weight of the crude product XII concentrated hydrochloric acid is added, the free carboxylic acid having a melting point of 166 to 167 C. precipitates after dilution with

The 4- [benzoxazole) l- (2 ')] - naphthoic acid (l) can KXK) parts of water is stirred for 1 hour, the

in the following way by the method of the Belgian · »* precipitate sucked off and washed with water.

Patent specification 691 803 are produced: 106 parts by weight of 4- [benzoxazolyl- (2)] -

48.8 parts by weight of naphthalene-1,4-dicarboxylic acid naphthoic acid - (1) \ om melting point 274 to DimethyleMers with a solidification point of 64.9 C become 275.5 C.

Dissolved warm in 2 (Xl parts by volume of methanol. At 40 C

a solution of 8 parts by weight of sodium hydroxide in 25 parts by weight of water is added dropwise with thorough stirring, and 1 kg of caprolaclam is stirred for a further 2 hours. 30 g of water. 4 g TiQ; and 0.8 g under reflux. Then two of the compound XII (table) are distilled off in a stirred car third of the methanol. The residue is kept at 240 ('(under pressure (.WX is then added) parts by weight of water and heated for 60 minutes while releasing the pressure Water acidified. Quenched in water, chipped in tape form. The precipitate that has formed is filtered off with suction, free and dried. The raw material has been washed with hydrochloric acid and, with a solution of a correspondingly prepared blank product, 30 parts by weight of sodium hydrogen carbonal in ^(l ° strongly increased whiteness. In 600 parts by weight of water can be stirred in the same way, the compound XI (table) also being used. The saponification products dissolve while not converted - (2)] - will. The free carbo Acid becomes naphthoic acid (I) by acidification. 19.6 parts by weight Thionvichlomii a mixture \ on 35 parts by weight concen- ^(l 5 chloride and 218 parts by weight of toluene can Säuie-UK'Her hydrochloric acid and produced 50 parts by weight of water until chloride adding to a 70 C warm suspension reprecipitated, suction filtered and washed with water overall of 17.1 Parts by weight of 5-amino-4-hydroxy -1.2 - \ lol and dried. 40 parts by weight ( ¹ J """isi) in 84 parts by weight of toluene and 15.3 parts by weight are obtained.

weight parts of dimethylaniline run in. The mixture was 2 '/ o at 75 ^hours: C stirred, then to 5 to 10' C cooled, suction filtered and the filter residue subjected to a steam distillation. After drying, 43 parts by weight of the acylamino compound with a melting point of 279 to 281 ° C. (with decomposition) are obtained.

This intermediate product is mixed with 0.2 parts by weight of zinc chloride and 174 parts by weight of 1,2,4-trichlorobenzene in a nitrogen atmosphere Heated to 215 to 220 C for 3 hours. 70 parts by weight of methanol are added during cooling, Sucks off cold and the product washes several times with methanol. After drying, 39.5 parts by weight are obtained of the compound XI, which can be obtained by recrystallization from toluene with the addition of activated charcoal cleans, whereby the melting point rises to 237 to 238 C.

Compound X (table) can be prepared in an analogous manner.

Example 3

Suspension vinyl chloride is converted into titanium dioxide and 0.05 percent by weight with the addition of 3 percent by weight the compound XII (table) by rolling at 80 C (for 15 minutes) a hard film manufactured).

The film has a significantly higher degree of whiteness than one in the same way, but without the addition of the Foil made by brightening agent.

Compound XII also shows a similarly good effect in films made using emulsion polyvinyl chloride were manufactured.

Example 4

A conventionally bleached fabric made of polyethylene glycol terephthalate threads, which still has a slight yellow tinge, is treated for 1/2 hour with an aqueous dispersion containing 0.1 g / l of compound X (table) at 98 ^° C. in a liquor ratio of 1: 20 treated.

The fabric then showed an excellent shade of white, which was also evident after 100 hours of exposure a xenon high-pressure lamp is not significantly weakened.

B e i s ρ i e 1 5

A raw fabric made of polyethylene glycol terephthalate threads is treated in a liquor ratio of 1:20 with a bleaching liquor containing 0.6 g of sodium chlorite (10O ⁰ AlIg), 0.2 ml of glacial acetic acid, 0.2 ml of concentrated sulfuric acid and 0.1 g of compound X per liter . After slowly heating up, the temperature is initially maintained at 80 to 85 ° C. for 30 minutes and then at 98 ° C. for 30 minutes. The white shade of the fabric treated in this way is brilliantly clear.

B e i s ρ i e 1 6

A fabric made of polyethylene glycol terephthalate threads, bleached in the usual way is impregnated with an aqueous dispersion of 5 g / l of compound X 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 beautiful, even shade of white.

N constitution Melting point ^ N _x / x / CH ₃ X / N. 204 to 205 ⁰ C - / \ ^ N .. / WCH ₃ XI o ⁷ 237 to 238 ° C O CH ₃ N CH ₃ ( ^{ >)
■ y _o / ^ Nv / ,. .C-CH ₃ XII ^ / ^/ ~ ^Q χ / _X J CH ₃ 166 to 167 ° C / \
/ C \ / c— (
/

Claims (1)

Claim: Further development of the use of yellow, in solution reddish to greenish blue fluorescent benzoxazo compounds as optical brightening agents according to patent 1,282,592, according to which compounds of the general formula 909 546/85 are used, in which the radicals Ri and R2 a hydrogen atom, an alkyl or aryl group, a halogen atom or together one condensed hydroaromatic ring signifies th, characterized in that one yellowish to yellow, reddish in solution to greenish blue fluorescent benzoxazole compounds of the general formula in which the residues Ri to Ri are a hydrogen atom or a low molecular weight alkyl group containing up to 4 carbon atoms and 15 ' in which the two benzoxazolyl radicals are differently substituted, also as optical Whitening agent used.