US2737516A - Fluorescent whitening agents - Google Patents

Fluorescent whitening agents Download PDF

Info

Publication number
US2737516A
US2737516A US505559A US50555955A US2737516A US 2737516 A US2737516 A US 2737516A US 505559 A US505559 A US 505559A US 50555955 A US50555955 A US 50555955A US 2737516 A US2737516 A US 2737516A
Authority
US
United States
Prior art keywords
parts
oxazole
acid
naphth
phenyl
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US505559A
Inventor
Sartori Mario Francesco
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
EIDP Inc
Original Assignee
EI Du Pont de Nemours and Co
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by EI Du Pont de Nemours and Co filed Critical EI Du Pont de Nemours and Co
Priority to US505559A priority Critical patent/US2737516A/en
Application granted granted Critical
Publication of US2737516A publication Critical patent/US2737516A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Classifications

    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07D—HETEROCYCLIC COMPOUNDS
    • C07D263/00—Heterocyclic compounds containing 1,3-oxazole or hydrogenated 1,3-oxazole rings
    • C07D263/52—Heterocyclic compounds containing 1,3-oxazole or hydrogenated 1,3-oxazole rings condensed with carbocyclic rings or ring systems
    • C07D263/62—Heterocyclic compounds containing 1,3-oxazole or hydrogenated 1,3-oxazole rings condensed with carbocyclic rings or ring systems having two or more ring systems containing condensed 1,3-oxazole rings
    • C07D263/64—Heterocyclic compounds containing 1,3-oxazole or hydrogenated 1,3-oxazole rings condensed with carbocyclic rings or ring systems having two or more ring systems containing condensed 1,3-oxazole rings linked in positions 2 and 2' by chains containing six-membered aromatic rings or ring systems containing such rings

Definitions

  • anagent for the purposes of this invention should be capable of being synthesized economically from readily available materials, and should have suflicient fluorescent power (often referred to as tinctorial strength) to give the desired efiect at a minimum cost. It should also have aflinity for the fibers to which it is applied, and should be capable of being dispersed readily in water in the concentrations that would normally be used in the treatment of nylon or cellulosic fibers.
  • novel compounds are synthesized which satisfy to an excellent degree all the aforegoing qualifications.
  • the novel compounds 'of this invention may be defined by the general formula wherein X stands for O, S or NH; Y represents a sulfo group, and n is zero or one.
  • These compounds may be synthesized by condensing the corresponding p-2-benzazolyl)-benzoic acid of formula with l-amino-Z-naphthol or a monosulfo-derivative thereof by the aid of an acid halogenating agent, such as phosphorus oxychloride, phosphorus trichloride or thionyl chloride, in a suitable liquid medium and at moderatetemperature, say to C., to form an intermediate condensation product, presumably an orthohydroxy amide, and .then ring-closing the latter into a naphthoxazole compound, by heatingat a higher temperature, say in the vicinity of to 220 C.
  • an acid halogenating agent such as phosphorus oxychloride, phosphorus trichloride or thionyl chloride
  • liquid meditnn a high-boiling, inert organic solvent is recommended, for instance trichlorobenzene, diphenyl ether, or alphaor beta-methyl naphthalene.
  • inert organic liquids of somewhat lower boiling point are also suitable, for instance pyridine.
  • the monosulfonated product may be prepared by sulfonating the product obtained as above from l-arnino- Z-naphthol, or by starting initially with a monosulfonatedl-amino-Z-naphthol. Sulfonation of the condensed product is readily achieved by treating the same with sulfuric acid monohydrateyat room temperature.
  • EXAMPLE 2 2-[p-(2-benzimidazolyl) phenyl] -mzphth [1,2 oxazole sodium sulfonate 5 parts of the product prepared in Example 1 were dissolved in 50 parts of sulfuric acid monohydrate and stirred at room temperature. When a test portion ofthe sulfonation mixture dissolved to give a clear solution in dilute sodium carbonate, the reaction mixture was poured into 500 parts of iced water. The precipitate was filtered off and washed. The yellow filter cake was dispersed in water,.the dispersion was made alkaline with sodium carbonate to form a solution and the product was finally precipitated by adding sodium chloride.
  • the pale yellowish precipitate was filtered off, washed thecornpound in dimethylformamide is located at 365 millimicrons.
  • EXAMPLE 3 A suspension of-2.6 parts of-p-(2-benzimidazolyl)benzoic acid, 2.4 parts of 1-amino-2-hydroxy-4-naphthalenesulfonic acid and 1.7 parts of phosphoryl chloride in parts of pyridine was heated at 70 C. for 1 hour and then at 110 C. for. 3 hours. After cooling to room temperature, the mixture was drowned in water, made acid to Congo red with hydrochloric acid and'filtered. The filter cake (o-hydroxy-amide) was first washed with cold water, then with ethyl alcohol. and dried. The crude product thus obtained was slurried in parts of trichlorobenzene and heated at.200 C. for 8 hours. After cooling to room.
  • the absorption maximum of this compound in dimethylformamide is located at 368 millimicrons.
  • EXAMPLE 5 Uponsulfonation of the product of,Example 4 by the method described in Example2, 2- [p-(2-benzothiazolyl) phenyll-naphthl1,2]oxazole' sodium sulfonate was ob-v tained. It is a pale yellowishpowder, soluble in dilute sodium carbonate,. and havingthe formula fluoresces blue, and its absorption maximum is located at 370 millimicrons..
  • the initial p-(2-benzoxazolyl)benzoic acid was prepared as follows: A suspension of 20 parts of methylhydrogen terephthalate and 11 parts of orthoaminophenol in 110 parts of trichlorobenzene was heated at C. for 3 hours and at 200 C. for 16 hours. After cooling to room temperature the reaction mass was filtered and washed with petroleum ether. The filter cake was slurried in 500 parts of water containing an excess of sodium carbonate, the slurry was boiled for 5 minutes and filtered hot. After clarification with activated carbon the filtrate was made acid with acetic acid. The white precipitate was filtered off, washed at 50 C. with ethanol andgd'ried. A white powder of M. P. above 300 C. was obtained.
  • the monosulfonated products are useful for cotton fiber.
  • the unsulfonated ones can be used both'onicotton and on nylon.
  • the compounds given in the above examples havebeen isolated as the sodium salts of the sulfonic acids.
  • potassium hydroxide and potassium salts in lieu of sodium hydroxide and sodium salts, throughout, the productsmay be obtained as potassium sulfonates. Isolation as the free sulfonic acids can be efiFected by acidification of the condensation mass, andthe products thus obtained may be reacted with ammonium hydroxide or any suitable organic or inorganic base, to yield the corresponding salt.
  • my novel compounds may also be used for various other purposes where fluorescence or absorption of ultraviolet light is desirable, for instance to achieve fluorescent effects in costumes or stage settings, to achieve novel eifects on photographic paper, as ultraviolet filters when impregnated on cellulosic films which are used for Wrapping materials, etc.
  • a fluorescent agent which comprises condensing a carboxylic acid of the group consisting of p-(Z-benzimidazolyl)benzoic acid, p-(Z-benzothiazolyl)benzoic acid, and p-(2-benzoxazolyl)benzoic acid, in an inert organic liquid and in the presence of an acid halogenating agent, with an ortho-amino-naphthol of the group consisting of 1-amino-2-naphthol and l-amino- 2-naphthol-4-sulfonic acid to give an intermediate condensation product, and further heating the said intermediate condensation product in an inert organic liquid to effect conversion thereof into an oxazole compound.

Description

2,737,516 Patented Mar. 6, 1956 k a "2,737,516 1 FLUORESCENT WHITENING AGENTS Mario Francesco Sartori, Wilmington, Del.,'assignor to E. I. du Pont de Nemours and Company, Wilmington, DeL, a corporation of Delaware No Drawing. Application May 2, 1955 Serial No. 505,559
6 Claims. Cl. 260-304) ,This invention relates to the production of novel organic compounds which are useful as whitening agents for various fibrous materials, including cellulosic fibers and nylon. It is an object-of this invention to produce compounds-of the above general nature, but which are characterized further by bleach fastness and by correct shade of fluorescence. Additional objects and achievenients of this invention will appear as the description proceeds.
'The art of whitening or brightening textile'fiber and paper is of relatively recent development. It has been found that fibrous materials which normally have a dull, yellowish cast when in the white, unbleached state, become whiter and brighter if treated with agents which fluoresce underultraviolet light. Presumably the action of the ultraviolet rays present in ordinary daylight is sufiicient to excite these agents upon the fiber to emit fluorescence which overcomes the undesirable tinge of color in the unbleached fiber. Best results are obtained when the shade of fluorescence is complementary to that of the unbleached fiber, so that the colors will cancel out each other. Since the most common off-white shade of unbleached cellulosic and nylon fibers is yellowish, the most desirable shade in a fluorescent is blue.
Another very important demand developed by the trade is bleach fastness. Inasmuch as the aforementioned fluorescent agents are generally incorporated into soap and synthetic detergents, which are packaged and marketed for household use, and'inasmuch as in household practice laundered articles are often subjected to bleaching with various agents, for instance hypochlorites, it is essential that the fluorescent transferred from the detergent to the fiber shall not berremoved or destroyed by the action of bleach. Unfortunately, most of the fluorescent agents now on the market, and having the desirable blue shade, are weak in respect to this qualificatiofi o'f bleach resistance. I
In addition to the above two primary qualifications, anagent for the purposes of this invention should be capable of being synthesized economically from readily available materials, and should have suflicient fluorescent power (often referred to as tinctorial strength) to give the desired efiect at a minimum cost. It should also have aflinity for the fibers to which it is applied, and should be capable of being dispersed readily in water in the concentrations that would normally be used in the treatment of nylon or cellulosic fibers.
a Now according to my invention. new chemical compounds are synthesized which satisfy to an excellent degree all the aforegoing qualifications. The novel compounds 'of this invention may be defined by the general formula wherein X stands for O, S or NH; Y represents a sulfo group, and n is zero or one.
According to accepted nomenclature, they may be named collectively as 2-[p-(2-benzazolyl)phenyl]- naphth[1,2]oxazole.s and their monosulfo derivatives.
These compounds may be synthesized by condensing the corresponding p-2-benzazolyl)-benzoic acid of formula with l-amino-Z-naphthol or a monosulfo-derivative thereof by the aid of an acid halogenating agent, such as phosphorus oxychloride, phosphorus trichloride or thionyl chloride, in a suitable liquid medium and at moderatetemperature, say to C., to form an intermediate condensation product, presumably an orthohydroxy amide, and .then ring-closing the latter into a naphthoxazole compound, by heatingat a higher temperature, say in the vicinity of to 220 C. As suitable liquid meditnn, a high-boiling, inert organic solvent is recommended, for instance trichlorobenzene, diphenyl ether, or alphaor beta-methyl naphthalene. For the amide formation step, inert organic liquids of somewhat lower boiling point are also suitable, for instance pyridine.
The monosulfonated product may be prepared by sulfonating the product obtained as above from l-arnino- Z-naphthol, or by starting initially with a monosulfonatedl-amino-Z-naphthol. Sulfonation of the condensed product is readily achieved by treating the same with sulfuric acid monohydrateyat room temperature.
Without limiting this invention, the following examples are given to illustrate my preferred mode of operation. Parts mentioned are by weight.
EXAMPLE 1- 2- [p-(Z-benzimidazolyl)phenyl] -napl zth [1,2] oxazole A suspension of 2.6 parts of p-(2-benzimidazolyl)- benzoic acid (Ann. 205, 118), 2 parts of 1-amino-2- naphthol hydrochloride and 1.8 parts of phosphoryl chloride in 30 parts of trichlorobenzene was heated at 125 C(for 1 hour and then at 200 C. for 5 hours.
After cooling to room temperature, the precipitate was filtered off and washed with petroleum ether. The gray filter cake was slurried at 50 C. with an excess of 5% sodium carbonate aqueous solution, filteredhot, washed and dried. Cream-colored crystals of M. P. 292 C. were obtained. The absorption maximum of this compound in dimethylformamide is located at 364 millimicrons.
Analysis.Calc. for C24H15ON3: C, 79.5; H, 4.1; N, 11.6. Foundz C, 79.6; H, 4.1; N, 12.3.
EXAMPLE 2 2-[p-(2-benzimidazolyl) phenyl] -mzphth [1,2 oxazole sodium sulfonate 5 parts of the product prepared in Example 1 were dissolved in 50 parts of sulfuric acid monohydrate and stirred at room temperature. When a test portion ofthe sulfonation mixture dissolved to give a clear solution in dilute sodium carbonate, the reaction mixture was poured into 500 parts of iced water. The precipitate was filtered off and washed. The yellow filter cake was dispersed in water,.the dispersion was made alkaline with sodium carbonate to form a solution and the product was finally precipitated by adding sodium chloride.
The pale yellowish precipitate was filtered off, washed thecornpound in dimethylformamide is located at 365 millimicrons.
EXAMPLE 3 A suspension of-2.6 parts of-p-(2-benzimidazolyl)benzoic acid, 2.4 parts of 1-amino-2-hydroxy-4-naphthalenesulfonic acid and 1.7 parts of phosphoryl chloride in parts of pyridine was heated at 70 C. for 1 hour and then at 110 C. for. 3 hours. After cooling to room temperature, the mixture was drowned in water, made acid to Congo red with hydrochloric acid and'filtered. The filter cake (o-hydroxy-amide) was first washed with cold water, then with ethyl alcohol. and dried. The crude product thus obtained was slurried in parts of trichlorobenzene and heated at.200 C. for 8 hours. After cooling to room. temperature the'precipitated product was filtered off, washed. withpetroleum: ether, dissolved in dimethylformamideandi then reprecipitated by adding an equal weight of an aqueous, 10% salt solution. The product has the formula The water solution of this compound exhibits a strong blue fluorescence. The. absorption maximum of this compound in dimethylformamide is located at 365 millimicrons.
A mixture of 4.5 partsof' p-(2-benzothiazolyl)benzoic acid (Chem. News, 124,. 393), 3 parts of 1-amino-2- naphthol hydrochloride and 2.8 parts of phosphoryl chloride was condensed following the method described in Example 1 for the preparation. of the analogous benzimidazole derivative. Cream colored crystals of M. P. 256 C. were obtained.
Analysis-Cale. for C24H'i4N2SO: C, 74.2; H, 3.6; N; 7.4; S, 83. Found: C,. 75.2; H, 3.4; N, 7; S, 8.
The absorption maximum of this compound in dimethylformamide is located at 368 millimicrons.
EXAMPLE 5 Uponsulfonation of the product of,Example 4 by the method described in Example2, 2- [p-(2-benzothiazolyl) phenyll-naphthl1,2]oxazole' sodium sulfonate was ob-v tained. It is a pale yellowishpowder, soluble in dilute sodium carbonate,. and havingthe formula fluoresces blue, and its absorption maximum is located at 370 millimicrons..
EXAMPLE 6 2- [p- (2-benz0xaz0lyl) phenyl] -naph th [1,2 loxazole A suspension of 2.6 partsof. p;(Z-benzoxazolyDbenzoic acid,(prepared as,described.below.), 2parts of 1 -amino-2- naphthol hydrochloride and 1.7 parts of phosphoryl chloride was condensed following the procedure described in Example 1. Pale yellowish crystals of M. P. 320325 C. were obtained.
Analysis.-Calc. for C24H14O2N2: C, 79.2; H, 3.85; N, 7.7. Found: C, 79.8; H, 3.9; N, 7.4.
The initial p-(2-benzoxazolyl)benzoic acid was prepared as follows: A suspension of 20 parts of methylhydrogen terephthalate and 11 parts of orthoaminophenol in 110 parts of trichlorobenzene was heated at C. for 3 hours and at 200 C. for 16 hours. After cooling to room temperature the reaction mass was filtered and washed with petroleum ether. The filter cake was slurried in 500 parts of water containing an excess of sodium carbonate, the slurry was boiled for 5 minutes and filtered hot. After clarification with activated carbon the filtrate was made acid with acetic acid. The white precipitate was filtered off, washed at 50 C. with ethanol andgd'ried. A white powder of M. P. above 300 C. was obtained.
EXAMPLE 7 2- [17 (2-benz0xaz0lyl) phenyl] -naphth [1,2 1 oxazole sodium sulfonate N N SO;N8
o -o O EXAMPLE 8 2- [p-(Z benzoxazolyl ph enyl] -naphth [1,2 0xazole 5 -sodium sulfonate 5.3.parts of 2-(p-benzoxazolyl)benzoic acid were condensed with 4.8 parts of 1-amino-2-hydroxyr4-naphthalene-sulfonic acid and 3.4 parts of phosphoryl chloride in pyridine, ring-closed and purified: according to the procedure described in Example 3.
A yellowish powder, completely soluble in dilute sodium carbonate solutionwas obtained. The water: solution of. the sodium salt of thiscompound exhibits bluish fluorescence.
The novel products of the foregoing several examples weretested for whitening power and bleach resistance-by the sametests as-described in my copending application Serial No. 333,016, filed January 23, 1953 (Patenu'No; 2,715,632, issued August 16, 1955), and found. to be satisfactory in. both respects. The fluorescence imparted to a sample of cotton fabric by the novel agents. was
retained'in full (essentially in the bleach-.fastness test.
Tests for light-fastness, substantivity and washrfastness were also carriedrout, and-showed my novel compounds to. compare. favorably in respect to these qualities with the best. fluorescents which are now on the market.
The monosulfonated products are useful for cotton fiber. The unsulfonated ones can be used both'onicotton and on nylon.
The compounds given in the above examples havebeen isolated as the sodium salts of the sulfonic acids., By using potassium hydroxide and potassium salts in lieu of sodium hydroxide and sodium salts, throughout, the productsmay be obtained as potassium sulfonates. Isolation as the free sulfonic acids can be efiFected by acidification of the condensation mass, andthe products thus obtained may be reacted with ammonium hydroxide or any suitable organic or inorganic base, to yield the corresponding salt.
In addition to producing a whitening effect upon textile material or paper, my novel compounds may also be used for various other purposes where fluorescence or absorption of ultraviolet light is desirable, for instance to achieve fluorescent effects in costumes or stage settings, to achieve novel eifects on photographic paper, as ultraviolet filters when impregnated on cellulosic films which are used for Wrapping materials, etc.
I claim as my invention:
1. A compound of the group consisting of 2-[p-(2- benzimidazolyDphenyl]-naphth[1,2]oxazole, 2 [p (2 benzothiazolyl)phenyl]-naphth[1,2]oxaz0le, 2 [p (2 benzoxazolyDphenyl]-naphth[1,2]oxazole and t h e i r monosulfo derivatives.
2. 2 [p (2 benzimidazolyDphenyl] naphth[1,2]oxazole.
3. The S-sOdium-sulfonate of 2-[p-(2-benzimidazolyl) phenyl] -naphth 1,2] oxazole.
4. A sodium monosulfonate of 2-[p-(2-benzothiazolyl) phenyl] -naphth[ 1,2] oxazole.
5. A sodium monosulfonate of 2-[p-(2-benzoxazolyl) phenyl] -naphth 1,2] oxazole.
6. The process of producing a fluorescent agent which comprises condensing a carboxylic acid of the group consisting of p-(Z-benzimidazolyl)benzoic acid, p-(Z-benzothiazolyl)benzoic acid, and p-(2-benzoxazolyl)benzoic acid, in an inert organic liquid and in the presence of an acid halogenating agent, with an ortho-amino-naphthol of the group consisting of 1-amino-2-naphthol and l-amino- 2-naphthol-4-sulfonic acid to give an intermediate condensation product, and further heating the said intermediate condensation product in an inert organic liquid to effect conversion thereof into an oxazole compound.
No references cited.

Claims (1)

1. A COMPOUND OF THE GROUP CONSISTING OF 2-(P-(2BENZIMIDAZOLYL)PHENYL)-NAPHTH(1,2)OXAZOLE, 2-(P-(2BENZOTHIAZOLYL)PHENYL)-NAPHTH(1,2)OXAZOLE, 2-(P-(2BENZOXAZOLYL)PHENYL)-NAPHTH(1,2)OXAZOLE AND THEIR MONOSULFO DERIVATIVES.
US505559A 1955-05-02 1955-05-02 Fluorescent whitening agents Expired - Lifetime US2737516A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
US505559A US2737516A (en) 1955-05-02 1955-05-02 Fluorescent whitening agents

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US505559A US2737516A (en) 1955-05-02 1955-05-02 Fluorescent whitening agents

Publications (1)

Publication Number Publication Date
US2737516A true US2737516A (en) 1956-03-06

Family

ID=24010797

Family Applications (1)

Application Number Title Priority Date Filing Date
US505559A Expired - Lifetime US2737516A (en) 1955-05-02 1955-05-02 Fluorescent whitening agents

Country Status (1)

Country Link
US (1) US2737516A (en)

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3162644A (en) * 1961-07-14 1964-12-22 Albert Ag Chem Werke Nu-alkyl-2-benzoxazolyl urea compounds
US3268543A (en) * 1962-11-30 1966-08-23 Ciba Ltd Monoazolyl-thiophene derivatives
US3293258A (en) * 1964-06-19 1966-12-20 Ciba Ltd Certain 1-(2-benzoxazolyl)-4-(2-naphthoxazolyl)-benzene compounds
US3340064A (en) * 1963-07-22 1967-09-05 Agfa Ag Silver halide emulsions sensitized with cyanine dyes containing an oxazinetype ring
US3438994A (en) * 1963-07-09 1969-04-15 Gevaert Photo Prod Nv Methine dyes containing tricyanoalkyl-substituted phosphorus
US4308194A (en) * 1974-07-01 1981-12-29 Eastman Kodak Company Heterocyclic benzoate ultraviolet stabilizers and their use in organic compositions
US5298189A (en) * 1992-04-24 1994-03-29 Nanoptics Incorporated Proton transfer bis-benzazole fluors and their use in scintillator detectors
US5587112A (en) * 1994-09-02 1996-12-24 Philadelphia College Of Pharmacy And Science Benzazole compounds with ESIPT fluorescence

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
None *

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3162644A (en) * 1961-07-14 1964-12-22 Albert Ag Chem Werke Nu-alkyl-2-benzoxazolyl urea compounds
US3268543A (en) * 1962-11-30 1966-08-23 Ciba Ltd Monoazolyl-thiophene derivatives
US3438994A (en) * 1963-07-09 1969-04-15 Gevaert Photo Prod Nv Methine dyes containing tricyanoalkyl-substituted phosphorus
US3340064A (en) * 1963-07-22 1967-09-05 Agfa Ag Silver halide emulsions sensitized with cyanine dyes containing an oxazinetype ring
US3293258A (en) * 1964-06-19 1966-12-20 Ciba Ltd Certain 1-(2-benzoxazolyl)-4-(2-naphthoxazolyl)-benzene compounds
US4308194A (en) * 1974-07-01 1981-12-29 Eastman Kodak Company Heterocyclic benzoate ultraviolet stabilizers and their use in organic compositions
US5298189A (en) * 1992-04-24 1994-03-29 Nanoptics Incorporated Proton transfer bis-benzazole fluors and their use in scintillator detectors
US5587112A (en) * 1994-09-02 1996-12-24 Philadelphia College Of Pharmacy And Science Benzazole compounds with ESIPT fluorescence

Similar Documents

Publication Publication Date Title
US2737516A (en) Fluorescent whitening agents
US3470167A (en) Triazolyl styryl optical whitening agents
US2713057A (en) Fluorescent benzgtriazqle compounds
US2563493A (en) Sulfonated
US2702759A (en) Method of brightening fabrics with sulfonated dibenzothiophene dioxide derivatives
US2844594A (en) 3-aryl-7-dialkylaminocoumarins
US2713056A (en) Fluorescent whitening agents
US2547910A (en) Acylated derivatives of certain diamino distyrylbenzene disulfonic acids
US3222371A (en) Pyridotriazole brighteners
US2700044A (en) Compounds of the benzimidazolylphenyl-1, 2-naphthotriazole type, useful as whiteningagents
US2713055A (en) Whitening agents for cellulosic fiber
US2527427A (en) Stilbene disulfonic acid derivatives
US2700043A (en) Fluorescent whitening agents
US2702296A (en) Fluorescent whitening agents
US3839351A (en) Triazolyl-coumarins
US2704286A (en) Fluorescent whitening agents
US3784570A (en) 4-chloropyrazolyl compounds
US2715632A (en) Whitening agents for cellulosic fiber
US4271293A (en) Benzofuranyl-benzimidazoles
EP0023022B1 (en) Coumarine compounds, processes for their manufacture as well as the intermediate products used perse and their utilisation for the dyeing or printing of textiles
US3288786A (en) Naphthotriazole optical brighteners
US2713054A (en) Whitening agents for cellulosic fiber
US2715630A (en) Fluorescent whitening agents
US3459744A (en) V-triazole-(2)-stilbenes
US2733247A (en) Whitening agents fos cellulosic fiber