US2743231A

US2743231A - Process for the dyeing of nylon fibers and fabrics with 5-chlorosalicylic acid

Info

Publication number: US2743231A
Application number: US260766A
Authority: US
Inventors: David X Klein; Falcon James
Original assignee: Heyden Chemical Corp
Current assignee: Heyden Chemical Corp
Priority date: 1951-12-08
Filing date: 1951-12-08
Publication date: 1956-04-24
Anticipated expiration: 1973-04-24

Description

United States Patent O PROCESS. FoR THE. DYEING or. NYLON FIBERS FABRICS, WITH. S-CHLOROSALICYLIC ACID .3 Claims, (Cl. 8--55) Thiszinvention relates to the dyeing: of fibers, andmore specifically, to .a new andimproved methocl'for, dyeing fibers-ands fabrics of nylon, a synthetic linear polyamide.

Conventional methods employed in the dyeingof nylon fibers or fabrics involve the use .of various organic acids such as benzoic acid, salicyclic acid, tannic acid,,-etc.- as carriers or dye assistants. The. actual mechanism by which these acidsv improve the dyeing characteristicstof the'fibenor fabric is not known but it is believed thata swellingof the material is induced. which-allowsthe dye to disperse into the fiber where it is held until the carrier issremorved. at alater step in the dyeing= ;operation-. In the dyeing process, quantities as high as %,015 the organic acids are used as dye assistants. The useof such highiconcentrationsof. swelling. agents is undesirable: in that. .a resulting. shrinkage orplasticization. .of. the. nylon fiber. is elfected- Various attempts to, reduce the concentration offthe acid carrier invariably haveresulted in a corresponding reduction of the color yield, obtained in the subsequent dyeing step. In other words deeper coloration of the nylon. material to be. dyed? could onlyfbe obtained, hitherto, by increasing the concentration of the swelling agent used.

It-has now been found that substantially higl'rcolor yields are obtained 'in the dyeing of'nylon fibers and fabrics-when the material is exposed to a pretreatment with: aqueous solutions containing relatively small amounts, i. e. as low as about 0.5% by weight, of either S-chlorosalicylic acid or cresotinic acid (hydroxytoluic acid) prior to thedyeing operation. Surprisingly, the nylon fibers and fabrics pretreated with eithervof these organic acids are dyed to a deeper shade by various types of dyes as compared with untreated nylon fabric. orv nylon fiber treated with conventional carriers such: as; benzoic or salicylic acid or tannic acid, .the latter acid being used in a concentration as high as 10%. Because.

of their greater ability to increase the receptivity of nylon toivariousdyes, S-chlorosalicyclic acidorcresotinic acid may be used in a concentration. as:'low'as;0i5'% to obtain maximum. color depth as distinguished. from the organic acids used hitherto which required a concentration ranging from at least 2% to as high as 10% to achieve results considered to-befarless satisfactory in nature.

In a more specific embodiment of this invention, nylon fabric samples were treated in a relaxed state for three minutes at the boil in baths containing from 015% to 3% by weight of either cresotinic acid orS-chlbrosalicylic acid in aqueous solutions thereof. The samples were thoroughly washed in warm water followed by cold water to remove the acid carrier and then dyed for about thirty minutes at a temperature of 190 F. in a bath containing the appropriate dye.

Untreated samples of the same material were exposed in the same manner to a dyeing treatment in order to provide a control or basis for comparisons between samples exposed to pretreatment and those which had not. In a separate procedure, the fabrics were also treated with aqueous solutions con- 2,743,231 Patented Apr. 24, 1956 taining from 0.5% to 3% salicylic acid by weight and the results obtained by, the-use-of this acid were compared with those obtained by the use of the lower concentrations of 'S-chlorosalicylicacid or cresotinic acid. All of the nylon fabric samples subjectedtothese treat men-ts; were exposed to various dyes such' as acid dyes, direct dyes, and acetate dyes. Ir-ieachinstance, the samples pretreated with, 5-chlorosalicylic acid.and CI'ESG? tinicacidiwere considerably-.darkerin color thanieither thesample's pretreated with-salicylic acid or the. samples that were not exposed to any pretreatment.

Additional advantages and features of this new and highly improved process are set forth-in. the; following examples whichgdisclose. the principleof the.invention'.- and the preferred embodimentmof :applying that principle. It is understood, however, that these .examples'arer merely' illustrative andtnot :limitiativein nature; being capable: of variousrothermodifications;

EXAMPLE I Acid dyes Acid dyes are ordinarily employed in the dyeingof wo'olt These dyes-are azo dyes of lowermol'ecular weight. Nylon fabric samples were treated in a relaxed state for: three minutes at the boil in baths containing from- 0.5 to 3% -by weight of salicylic acid; cresotinic acid I andrS-chiorosali'cylicacid: The:sampleswere-thoroughly washed: inc-warm water followed by cold water and then' dyed together'with' an untreatedsampleof the samernaterialzfor :30: minutes at F. in a. dyebath. containing.

l.% ;acid. dye (onwweight of the fabric) 2%; H2SO4..( on weight of the fabric) 10%. NaCl (on ,weight'of tl1e fabric) Direct dyes Direct dyes-are used ordinarily in' dyeing cotton material. They are water soluble azo dyes containingsul phonic: acid groups.

Usingrthe' procedure described in Example I, samples ofi nyllon pretreated: with-aqueous solutions containing flfOl'IIiiOlS to 3%- by weightxofwS chlorosalicylic acid, cresotinic acid and salicyclicacid were dyed along? with an'untreated'sample ima dyebath containing-1%. of PontamineBluez 3R. (Colour Index No. 464) or Pontamine..Brilliant.Violet. (Prototyp Number 35-)" (both of which are manufactured by E. I. du Pont de Nemours and Co.) and 20% of sodium chloride based on the weight of the fabric. The water to fabric ratio was 25:1. In this case also, the samples pretreated with 1 The Colour Index Numbers and Prototype Numbers mentioned here and throughout the specification are a standard of identification for commercially important organic dyes listed in the Technical Manual and Year Book of American Assn. of Textile Chemists and Colorists, volume XXVI, 1950, page 150. Also referred to in Library Guide for Chemists, Soule, McGraw Hill Publishing Company, 1938.

3 S-chlorosalicylic acid and cresotinic acid were dyed to a much deeper shade than were the untreated sample and the samples treated with salicylic acid.

EXAMPLE III Acetate dyes These dyes are water insoluble and are normally employed in the form of aqueous dispersions.

The procedure described in Example I was repeated using a dyebath containing:

1% acetate dye-on weight of fabric 10% triton Xlon weight of fabric (alkylarylpoly ethylene oxide) (JACS 69, 334, 1947-Rohm and Haas Co.)

The water to fabric ratio was 30:1.

Acetamine Violet 2R (du Pont de Nemours and Co.) and Eastone Rubine C (Tennessee Eastman Corporation) were the acetate dyes used.

The samples pretreated with S-chlorosalicylic acid or with cresotinic acid were noticeably darker than those which were not pretreated or which were pretreated with salicylic acid.

EXAMPLE IV Comparison of activity of the acid carriers The relative activity of the various acid carriers in different concentrations and their effectiveness in increasing the affinity of nylon for various types of dyes is shown in the following table. The activity was determined by dyeing tests similar to those described in the preceding examples. Samples pretreated with cresotinic acid, S-chlorosalicylic acid and salicylic acid were dyed with Eastone Yellow GNS and SRA Red V11 (acetate dyesmanufactured by Tennessee Eastman Corp.), Pontamine Blue BR and Pontamine Brown NCR Conc. 150% (Colour Index No. 596) (direct dyes), Pontacyl Light Red BL Conc. and Pontacyl Brilliant Blue A Conc. (acid dyes manufactured by E. I. du Pont de Nemours and Co.), and Ponsol Brilliant Green 46 and Ponsol Dark Blue BRD Bbl. Pdr. (Colour Index No. 1099) (vat dyes). In the following table the lightest shade produced has 4 acid is raised beyond about 1% and up to about 10%, for practical reasons, the acid is used in a concentration of about 1%.

While the color values of the dyed nylon samples pretreated with 5-chlorosalicylic acid, cresotinic acid at 7 and F. are higher than those of the salicylic acid pretreated sample and the sample that was not pretreated, there is a marked increase in the color value of samples pretreated with 5-chlorosalicylic acid or cresotinic acid at a temperature between about F. and the boiling point of the bath.

Maximum color values are obtained when the pretreating solutions containing as little as 0.5% of S-chlorosalicylic acid or cresotinic acid are used and when the pretreatment process is carried out at a temperature varying between 180 F. to 200 F. for a period of three minutes and preferably, at a temperature of about F.

It is apparent from the foregoing that the invention is capable of various modifications and that, therefore, it is intended and desired to embrace within the scope of this invention such modifications and changes that are necessary to adapt it to varying conditions and uses, as defined by the scope of the appended claims.

We claim:

1. In a process for coloring nylon fibers and fabrics, the improvement which comprises pretreating the nylon material in an aqueous solution containing from 0.5% to 1.5% by weight of 5-chlorosalicylic acid and while the aqueous solution is at a temperature between 180 F. and the boiling point of the aqueous solution, washing the material thus treated and subsequently dyeing said material.

2. In a process for coloring nylon fibers and fabrics, the improvement which comprises pretreating the nylon material in an aqueous solution containing from 0.5% to 1.5% by Weight of S-chlorosalicylic acid, said pretreatment being efiected at a temperature ranging between about 180-200 F., washing the material thus treated and subsequently dyeing said material.

3. In a process for coloring nylon fibers and fabrics, the improvement which comprises pretreating the nylon material in an aqueous solution containing from 0.5% to 1.5% by weight of S-chlorosalicylic acid, said prebeen indicated by the number 1. treatment being effected at a temperature of about 5-Ch1orosalicy1lc Acid cresotinic Acid Salicylic Acid 0 0'.- trol 0.5% 1.0% 1.5% 2.0% 3.0% 0.5% 1.0% 1.5% 2.0% 3.0% 0.5% 1.0% 1.5% 2.0% 3.0%

Direct Dyes 0 6 6 5 0 5 5 6 5 6 1 1 2 2 3 1 Acid Dyes 5 s 5 6 6 6 0 5 6 5 1 1 1 2 a 1 Acetate Dyes I5 5 6 5 6 5 6 5 5 6 1 1 2 2 2 1 Vat. Dyes o 5 5 s 5 4 5 0 5 5 1 1 1 2 3 1 190 F., washing the material thus treated and subsequently dyeing said material.

References Cited in the file of this patent FOREIGN PATENTS Great Britain Dec. 8, 1948 OTHER REFERENCES American Dyestuff Reporter for February 4, 1952, p. P78.

American Dyestuif Reporter for May 14, 1951, p. 312.

Claims

1. IN A PROCESS FOR COLORING NYLON FIBERS AND FABRICES, THE IMPROVEMENT WHICH COMPRISES PRETREATING THE NYLON MATERIAL IN AN AQUEOUS SOLUTION CONTAINING FROM 0.5% TO 1.5% BY WEIGHT OF 5-CHLOROSALICYLIC ACID AND WHILE THE AQUEOUS SOLUTION IS AT A TEMPERATURE BETWEEN 180* F. AND THE BOILING POINT OF THE AQUEOUS SOLUTION, WASHING THE MATERIAL THUS TREATED AND SUBSEQUENTLY DYEING SAID MATERIAL.