CH552006A - Optical brightening agents - comprising phenanthrotriazole cpds, for brightening synthetic fibres etc. - Google Patents

Abstract

Phenanthotriazole deriv. of formula (I):- (where R1 and R2 are H or sulphonic acid gp; and R3 is H or low alkyl), (I) are prepd. from cpds. of formula (II) by saponifying the CN to COOH and (opt. after splitting off the low alkyl residue R3) lactonising the prod. (I) are useful as optical brightening agents, esp. for fibre-forming polymers such as polyesters, polyamides, polyurethanes, polyolefins, PVC, polyacrylonitrile etc.

Description

  

  
 



   The invention relates to a process for the preparation of new phenanthrotriazole derivatives of the formula
EMI1.1
 wherein R1 and R2 each represent a hydrogen atom or a sulfonic acid group, which is characterized in that in a compound of the formula
EMI1.2
 in which Rs denotes hydrogen or low molecular weight alkyl, the cyano group is saponified to form the carboxyl group and, after the lower alkyl radical Rs, if necessary, is lactonized.



   The saponification of the cyano group in a compound of formula (II) can, for. B. be done in acidic medium, e.g. B.



  when Rs is hydrogen, in an aqueous or aqueous organic acid solution, advantageously in 1 to 100% hydrochloric or sulfuric acid at an elevated temperature, e.g. B. 80 to 1200 C, preferably from 900 C to 1050 C, the lactone ring closure is usually accomplished at the same time.



   If Rs is a low molecular weight alkyl, it is advantageous to work in the presence of an aluminum halide, e.g. B. of aluminum bromide and preferably aluminum chloride in an inert organic solvent, e.g. B. in an optionally halogenated or nitrated aromatic hydrocarbon: benzene, toluene, xylene, chlorobenzene, ortho-dichlorobenzene, bromobenzene, nitrobenzene, ortho-nitrotoluene, etc. or in an aluminum chloride-sodium chloride melt or with pyridine or quinoline chlorohydrate or the chlorohydrates of pyridine base mixtures, at elevated temperature, e.g. B. at 60 to 1200 C. The alkyl group is often split off, the cyano group is saponified and the lactone ring is closed in the same operation.

  If this does not occur, the ring closure is advantageously carried out with a solution of hydrogen halide in a low molecular weight fatty acid such as propionic acid or acetic acid. However, other acidic condensing agents can also be used, e.g. B. zinc chloride or aqueous mineral acids.



   The compounds of formula (I) can be prepared in a conventional manner, for. B. by suction, if they are in suspension, by precipitation with a suitable agent and suction, by evaporation or steam distillation of the solvent and suction of the deposited product, etc. are isolated.



   The new phenanthrotriazolyl compounds of the formula (I) have excellent properties for the optical brightening of a wide variety of organic materials and plastics.



   Organic materials are primarily synthetic fiber-forming polymers such as polyesters, polyamides, polyurethanes, polyolefins (polyethylene, polypropylene), polyvinyl acetate, polyvinyl chloride, polyvinylidene chloride, polyacrylonitrile, modified polyacrylonitrile, cellulose triacetate, cellulose 21/2 acetate and polystyrene.



   The phenanthrotriazolyl compounds can be used in the usual manner, for example in the form of solutions in water or in organic solvents or of aqueous dispersions. Above all, however, they are incorporated into spinning and molding compounds with good success or added to the monomers intended for the production of plastics or to a precondensate of the same.



   Depending on the method of use, the concentration can be 0.001 to 0.5 / 0, preferably 0.01 to 0.2%, of the compounds mentioned, based on the material to be brightened. These compounds can be used alone or in combination with other brighteners, as well as in the presence of surface-active agents such as detergents, carriers or in the presence of chemical bleaching agents.



   The lightening effects obtained are distinguished by a neutral, blue-violet to blue fluorescence shade, a very high saturation limit and excellent lightfastness.



   Compared to the corresponding naphthotriazolyl compounds, the phenanthrotriazolyl compounds prepared according to the invention have increased effectiveness, more neutral shade and reduced volatility, i.e. H. improved fastness to sublimation.



   In the following examples, the parts are Ge weight point, the percentages are percentages by weight and the temperatures are given in degrees Celsius.



   example
25 parts of 2-methoxy-4-amino-a-cyan syllables are dissolved in a mixture of 59 parts of 350% hydrochloric acid and 500 parts of water by heating. On cooling, a suspension of the aminostilbene hydrochloride forms. This suspension is kept at about 100 and a solution of 7 parts of sodium nitrite in 30 parts of water is added all at once with stirring. The mixture is kept at 100 for 1 hour and then the excess nitrous acid is destroyed with sulfamic acid.



   On the other hand, 23 parts of finely powdered 9 aminophenanthrene hydrochloride are slurried in 120 parts of pyridine and 120 parts of 2N sodium hydroxide solution and this slurry is added to the above-mentioned diazo suspension at 5-100 in the course of 20-30 minutes. During 1 hour, the mixture is heated to 50-600 with stirring, then cooled, the precipitated red azo compound is filtered off with suction, washed neutral with water and dried. 22.7 parts of the ortho-aminoazo dye obtained are dissolved in 300 parts of pyridine. A solution of 30 parts of crystallized copper sulfate, 54 parts of 280% aqueous ammonia solution and 40 parts of water is added to this solution. The temperature is maintained at 90-950 and the resulting solution is refluxed.

  After cooling, crystals separate out, which are filtered off, washed first with cold acetone and then with hot water and dried.



   The crude triazolylcyanostilbene obtained in this way is purified from chlorobenzene by recrystallization.



   15 parts of this triazolylcyanostilbene are dissolved in 140 parts of benzene. 15 parts of anhydrous aluminum chloride are added to the solution, the mixture is heated and refluxed for seven hours. The solution is then added to a mixture of 300 parts of ice and 19 parts of concentrated hydrochloric acid.



   The benzene is then removed by steam distillation, the residue is filtered off with suction, washed with water and dried. After recrystallization from chlorobenzene, the phenanthrotriazolylcoumarin derivative of the formula is obtained
EMI2.1
 as a pale yellow substance with an intense blue-violet fluorescence, melting point 283-2840 (uncorr.).



   Usage example
A granulate of polyamide 6 (poly-e-caprolactam) is powdered in a mixer with 0.01-0.05 o / o its weight of the compound of the formula (III) and in an apparatus customary for the melt spinning process for 30 minutes at about 3000 melted under nitrogen, stirred at this temperature for 15 minutes and then brought to the spinning temperature of 2850. The mass is spun into a monofilament under a pressure of 3-5 atmospheres (nitrogen). The fibers obtained show a violet fluorescence in daylight. They appear much whiter and lighter than fibers made without a brightener.



   If polyester or polypropylene is used instead of polyamide and spun at 2900 or 2600, fibers of a higher degree of whiteness are also obtained than fibers produced comparatively without brighteners.



      PATENT CLAIMS
I. Process for the preparation of new phenanthrotriazole derivatives of the formula
EMI2.2
 wherein R1 and R2 each represent a hydrogen atom or a sulfonic acid group, characterized in that in a compound of the formula
EMI2.3
 in which Rs denotes hydrogen or lower alkyl, the cyano group saponifies to give the carboxylic acid and, after the lower alkyl radical Rg, if necessary, is lactonized.

 

   II. The compounds of the formula (I) prepared by the process according to claim 1.



   III. Use of the compounds of formula (I) prepared by the process according to claim I for the optical brightening of non-textile organic materials.

** WARNING ** End of DESC field could overlap beginning of CLMS **.



   

 

Claims (1)

** WARNING ** Beginning of CLMS field could overlap end of DESC **. EMI2.1 as a pale yellow substance with an intense blue-violet fluorescence, melting point 283-2840 (uncorr.). Usage example A granulate of polyamide 6 (poly-e-caprolactam) is powdered in a mixer with 0.01-0.05 o / o its weight of the compound of the formula (III) and in an apparatus customary for the melt spinning process for 30 minutes at about 3000 melted under nitrogen, stirred at this temperature for 15 minutes and then brought to the spinning temperature of 2850. The mass is spun into a monofilament under a pressure of 3-5 atmospheres (nitrogen). The fibers obtained show a violet fluorescence in daylight. They appear much whiter and lighter than fibers made without a brightener. If polyester or polypropylene is used instead of polyamide and spun at 2900 or 2600, fibers of a higher degree of whiteness are also obtained than fibers produced comparatively without brighteners. PATENT CLAIMS I. Process for the preparation of new phenanthrotriazole derivatives of the formula EMI2.2 wherein R1 and R2 each represent a hydrogen atom or a sulfonic acid group, characterized in that in a compound of the formula EMI2.3 in which Rs denotes hydrogen or lower alkyl, the cyano group saponifies to give the carboxylic acid and, after the lower alkyl radical Rg, if necessary, is lactonized. II. The compounds of the formula (I) prepared by the process according to claim 1. III. Use of the compounds of formula (I) prepared by the process according to claim I for the optical brightening of non-textile organic materials.