DE1469223C - Optical brightening agents - Google Patents

Description

(CH ₂ ),

■ 2) n,

CH = CH

CN

in which the radicals R ₁ and R ₂ denote an alkyl group, an alkoxy group, an aryl group or a halogen atom and R ₁ also denotes a hydrogen atom;

The subject of patent 1419 330 is the use of fluorescent benzoxazole compounds the general formula

CH =

CN

in which the radicals R ₁ and R ₂ denote an alkyl group, an alkoxy group, an aryl group or a halogen atom and R ₁ also denotes a hydrogen atom, as optical brightening agents.

From the French patent specification 1336 949 is a Process for the optical brightening of organic fiber material known, wherein the fiber material in an aqueous disperse system with a 2-styryloxazole compound the general formula

in which A is represented by alkyl, aryl or alkylene groups substituted benzene ring or a simple naphthalene ring fused to the oxazole ring, and R and R 'can be the same or different and are hydrogen, halogen, cyano groups, carboxyl groups or mean carboxylic acid ester groups, alkyl or aryl groups in which when dyeing with The usual type of disperse dyes are treated.

From this patent, however, the teaching of the main patent is that the substitution of benzoxazoline which means η = 1 or 2, can be used excellently as an optical brightening agent.

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 and acetylated cellulose.

The compound in which η for 1 and the cyano group in 4 position.

The benzoxazoles of the general formula I to be used according to the invention as brightening agents can be prepared in many ways, for example by reacting 6-aminoindanols (5) or S.oJ.S tetrahydro-S-aminonaphthols (2) with the acid chlorides of 2-, 3- or 4-cyanocinnamic acid and then heating the obtained N-acyl compounds in an inert gas atmosphere at temperatures of 150 to 300 ⁰ C, preferably 180 to 250 ⁰ C is, in which closed with dehydration of the oxazole ring. The direct reaction of the cyaninnamic acids with the above-mentioned o-aminophenols to give the oxazole compounds is possible if the components are used in a known manner in the presence of acidic catalysts, such as. B. boric acid, heated in inert organic solvents until the elimination of water has ended.

The lightening agents to be used according to the invention 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 with the aid of dispersants. The required quantities based on the weight of the goods and are from 0.001 to 1.0%, preferably from 0.01 to 0.5%.

The compounds can also be used together with chemical bleaching agents, e.g. B. oxidative or reductive, such as sodium chlorite, sodium dithionite, can be used.
Furthermore, the compounds to be used according to the invention can be added to commercially available detergents to beautify the items to be washed.

Furthermore, they can also use spinning and casting compounds

are added to the manufacture of artificial

Fibers, threads, films, foils or other structures are used.

The following examples are intended to demonstrate the versatility of the application show, but without this being limited to it.

For example

A fabric made of polyethylene glycol terephthalate fibers was single-bath in a liquor ratio of 1:20 bleached and tinted white. The bleach bath contains in liters

0.6 g sodium chlorite 100%,

, 0.3 g Na pyrophosphate,

0.15 g oleylmethyltaurine Na salt,

0.2 ml glacial acetic acid,.

pH 3.5 adjusted with sulfuric acid and

0.15 g aqueous dispersion of the compound II (melting point 215.5 to 216.5 ⁰ C)

II

C = N

The bleaching time was 30 minutes for 85 ° C. The liquor was then heated to the boiling point and whitened for another 30 minutes. With this one-bath procedure, the remission of the Tissue at a wavelength of 460 πΐμ by 18% be raised.

The compound of formula II can be prepared in the following way: At a temperature of 75 ° C Mixture of 34.2 parts of 6-amino-indanol- (5), 200 parts by volume of chlorobenzene and 31 parts by volume of dimethylaniline a solution of 4-cyano-cinnamic acid chloride at 60 ° C. in 220 parts by volume is slowly added with stirring Chlorobenzene, from 38.1 parts of 4-cyanocinnamic acid and 24 Parts by volume of thionyl chloride in chlorobenzene had been prepared and stirred for 2 hours at 75 ° C. The yellow acylamino compound is filtered off with suction at room temperature and through Freed from adhering chlorobenzene and dimethylaniline by steam distillation. After filtering off with suction and drying at 105 ° C., 63 parts are obtained (94% of theory) of the 4-cyano-cinnamoyl compound of 6-amino-indanols- (5) with a melting point of 262 to 265 ° C.

For conversion into the benzoxazole is heated this amide under nitrogen for 2.5 hours 21O ⁰ C internal temperature in 330 parts by volume of trichlorobenzene with the addition of 0.2 parts of anhydrous zinc chloride as a catalyst. The melt, which crystallizes on cooling, is mixed with 150 parts by volume of cyclohexane while still at 90 ° C. and filtered off with suction after it has cooled completely. This gives 49 parts of crude 2 - (p '- cyanostyryl) - indano - (5,6 - d) - oxazol II After purification by recrystallization the melting point of 215.5 to 216.5 C. ^0.

Example 2

A polyethylene glycol terephthalate fabric bleached in the usual way was impregnated in such a way that the liquor pick-up of the fabric 60% (based on the Weight of goods), 1 l of the padding liquor containing 10 g of aqueous dispersion of compound II.

The goods were then subjected to a stream of hot air for 60 seconds without intermediate drying

treated at 190 ° C. The whiteness was fully developed by this treatment, so that the remission from 85 to 100.5%, measured at 460 ΐημ.

B e i s ρ i e 1 3

A bleached Polycaprolactamgewebe was washed in a liquor ratio of 1:20 at a temperature of 6O ⁰ C for 15 minutes.

11 of the wash liquor contained the following additives:

0.15 g coconut fatty alcohol with 5 mol ethylene oxide,

0.30 g coconut fatty alcohol with 8 mol ethylene oxide, 0.18 g carboxymethyl cellulose,

0.75 g Na pyrophosphate,

0.75 g sodium tripolyphosphat,

0.50 g sodium metasilicate,

0.50 g sodium carbonate,

0.75 g Na sulfate and

0.30 g aqueous dispersion of the compound II.

The whiteness of the fabric could be improved considerably (from 85 to 100%) by adding compound II will.

Example 4

The following optical brighteners have been used for their whitening effect on polyethylene glycol terephthalate fabrics compared:

A. 2- (p-Cyanstyryl) -indano- [5,6-d] -oxazole (Compound II),

B. 2 - (p - Cyanstyryl) - 6,7,8,9 - tetrahydro - naphth- [1,2 - d] - oxazole (French patent specification 1 336 949, table, compound 13),

C. 2 - (p - Cyanstyryl) - 5,7 - dimethyl - benzoxazole (French patent specification 1336 949, table, Connection 9),

D. 2 - (p - cyanstyryl) - 5,6 - dimethyl - benzoxazole (Belgian patent 633,434, examples 2 to 4).

The above-mentioned optical brighteners were predissolved in a small amount of dimethylformamide and the solution was stirred into water. In the whitening baths thus obtained, pre-bleached polyethylene glycol terephthalate fabrics were placed in a liquor ratio of 1:20 in a customary printing dyeing machine. The baths were heated to 120 ° C. over a period of 30 minutes and this temperature was maintained for 45 minutes. Subsequently, the fabrics were rinsed in a conventional manner for 10 minutes each at 80 and 4O ⁰ C and then dried.

To determine the degree of whiteness, the remission of the lightened tissue obtained in this way was measured in determined with a whiteness measuring device at a wavelength of 460 nm (magnesium oxide as standard = 100% of remission):

sample 60 2 Brightener concentration
(g / l) Remission 3 4th ■ - ■ ■ - 78.4 65 < A. 0.05 95.6 6th B. 0.05 90.8 ■ 7 C. 0.05 89.9 D. 0.05 92.1 A. 0.1 98.8 B. 0.1 92.4

continuation

sample Brightener concentration
(g / I) Remission 8th
9 C.
D. 0.1
0.1 91.7
93.8

As can be seen from the table, the compound A to be used according to the invention is the next

comparable previously known compounds with regard to the lightening capacity of polyethylene glycol terephthalate think. The superiority is particularly evident in the fact that with increasing concentration of optical brighteners in the treatment liquor, a greater increase in the degree of whiteness obtained is achieved is as compared with the compounds. In addition, with the compound A in the concentration ypn 0.05 g / l achieved a stronger whitening effect than with the comparison compounds in twice the concentration.

Claims (1)

I 469 223 Claim: Use of benzoxazoles of the general formula CH (CH ₂ ), CH = CH ~ ^ in which η denotes 1 or 2, as an optical brightening agent, in particular according to the benzoxazole compounds of the general formula used as optical brightening agents in Patent 1419 330 core in the 6 position · is particularly advantageous. not to be found. Corresponding connections, which also carry substituents in the 6-position of the benzoxazole radical are from the Belgian Patent 633 434 known, which corresponds to the main patent application. The known connections are good optical brightening agents particularly suitable for optical brightening of polyester fibers are. It turned out, however, that the thus obtained Effects can be increased. In a further embodiment of the main patent it has now been found that colorless or almost colorless, 'fluorescent benzoxazole compounds, which correspond to the general formula I, ■