US2179371A - Dyeing textile materials - Google Patents

Description

- objects Patented Nov. 7, 1939 PATENT OFFICE DYEING TEXTILE MATERIALS Colver IQDyer, Winchester, Mass, assignor, by

mesne assignments,

Monsanto Chemical Company, a corporation of Delaware No Drawing. Application May 29, 1936, Serial N0. 82,523

7 Claims.

The present invention relates to the dyeing of fibrous materials and it has particular relation to the dyeing of such materials as wool or leather which are composed of proteinous fibers or filaments.

The main objects of the invention are to provide:

A material for obtaining so-called level" or uniform impregnation of the fibers by the dye.

'A material for producing uniformity of color in union" and speck dyeing. These and other will be apparent from consideration of the following specifications and the appended claims.

In the dyeing of wools, leathers and similar materials containing protelnous substances as essential constituents of the fibers, difiiculty is experienced by reason of the fact that some dyes do not uniformly penetrate into the fibers and as a result more or less mottled, streaky, uneven effects are obtained. Such dyes are termed "unlevel". This is especially true in the case of certain cheap dyes, some of which are extremely resistant to fading and discoloration under the influence of washing, exposure to light, and perspiration, and which, if they were leve would have gone onto much wider use than they have heretofore enjoyed. In consequence, dyers have been forced to resort to the use of much more expensive materials, some of which were also characterized by low resistance to fading and discoloration by the above indicated agencies. It has been proposed to overcome the unlevel effects of the first mentioned class of dyes by conducting dyeing operations in the presence of certain agents, notably Glaubers salt. While these agents produced some improvement, they were never entirely satisfactory.

Difiiculty has also been experienced in the dyeing of mixed fabrics composed of threads or fibers of wool interspersed with threads or bits of cotton or the like cellulosic materials, because the wool tended to absorb dye more readily than the cellulosic fibers and as a result uniform color of the finished product could not be obtained.

The present invention is cased upon the discovery that certain reaction products of formaldehyde and sulfonated aromatic compounds, such as naphthalene, when incorporated into dye solutions have the property of producing highly uniform impregnation'of proteinous fibers composing such materials as wool, leather or the like and excellent level effects are obtained even with dye compounds which have heretofore been so unlevel in characteristics as practically iCl. 8-44.)

to inhibit their use at least in the finer grades of materials. Great uniformity of color is also produced upon textile materials consisting of wool or similar proteinous materials mixed with cotton or similar cellulosic materials. It thus becomes 5 possible to dye mixed fabrics to substantially uniform color by application of the foregoing reaction products.

Certain condensation products of naphthalene sulfonic acid and-formaldehyde have heretofore'lil been suggested as synthetic tanning agents and are termed syntans. While the compounds preferred in the practice of the present invention are related to the syntans, they are characterized by higher molecular weight and a slower rate of solution (in the undiluted state) in water than the ordinary synthetic tanning agents. They, also, have the power of reducing the rate of. absorption of dyes from baths by certain materials, notably wooL to a much greater degree than the ordinary synthetic tanning agents. These characteristics constitute convenient tests for distinguishing applicants preferred material from the'ordinary synthetic tanning agents.

The new dye retarding compounds are readily obtained by condensing sulfonated aromatic compounds such as naphthalene with formaldehyde. Usually the degree of sulfonation should correspond at least to the mono-sulfonic acid derivative of the aromatic compound and pref- 3Q erably it should approach that theoretically required for di-sulfonation. Very satisfactory results are obtained when the suite group is combinedin the ratio of approximately 1.6 or 1.? mols per mol. of naphthalene. This may be obtained by heating two parts by weight of 100% sulfuric acid with one part of naphthalene at a temperature of 140 C. for a period of three hours.- The sulfonatlon of naphthalene and similar organic compounds by means of concentrated sulfuric acid or chlor-sulfonic acid is well known to those skilled in the art and detailed discussion is not deemed to be necessary. The sulfonated naphthalene when cool is admixed in a closed vessel with 12 liters of water per 22 kilos of original naphthalene, and formaldehyde of 37% by weight concentration in a suitable ratio. Ratios of from .47 to about 1 part of formaldehyde to 1 part of original naphthalene and even somewhat higher or lower may be used but the ratio of about 1 part of naphthalene to 0.7 part formaldehyde is deemed to be preferable. The

addition of formaldehyde requires about four hours and the sulfonic acid solution is maintained during this period at a temperature of about 80 C. After all of the formaldehyde has American Association of Textile Chemists as been added, the temperature is raised to and 208. should also contain of 28% with the dye levelling compound in appropriate amount (e. g. 20%) based upon the weight or the test wool to be dyed.

amount of material is equivalent to 1.5% of naphthalene upon a like basis.

The wool sample equals 2.2% by weight of the water in the bath. The temperature of the bath is initially about 50 C. It is then brought up to a temperature of 94 C.

one-half hours. A four kilo portion of water 5 is then added and reaction is continued as a final stage for six to twenty hours longer. 'lemperature difierences greater than 2 C. in various parts of the bath are to be avoided during the reaction.

15 time and temperature of reaction ingly adjusted. If the amount of water is materially reduced, it is desirable to reduce the reaction temperature in order to slow down the rate of reaction sufllciently to admit of proper 20 tests for determination oi the degree of reaction.

The following constitutes a suitable test for determination of the suitability or the material for use in dyeing operations:

Take a sample equivalent to .78 gram of the original naphthalene, which sample, it the material is foregoing directions, grams. The sample with agitation to 1500 cc. of water having a temperature of 90 C. The time required for the material to pass into solution is found to vary with the degree of reaction of vals and titrated in accordance with standard procedure with titanium trichloride solution. -The degree of dye fixation 30 Dgle Dyo soln+20% so new condense- Percent dye theorized tram bath blank tion product It will be noted that with the highly condensed product constituting the subject matter of the slightly 1955' but Products dissolving Within present invention, the time required to obtain about ten minutes are also satisfactory for many 40% wsommon of the d e is more than twice Purposesas great as that required to obtain an equal At the end of the reaction, soda dry degree of ahwrpgion m the blank as a Solution, is added to the hot In the dyeing 0f was! the absve described material may be employed with satisfactory results over a wide range of proportions. As little as 0.3 of 1% will in some cases produce notable levelling efiects and as much as 3G% or even more may in some cases be employed. Probably best results are obtained by employing from to 20%. These values are based upon the weight of wool contained in the fabrics which are to be treated. The proportion of water into solution 65 2:3 to 45 times the The proportion of dye, of course, will depend upon the intensity of the shade desired, the nature of the dye employed so that the levelling action and various other factors as well understood by upon the absorption of dyes is relatively low those skilled inthe art. However, if the reaction between the aromatic Application of the condensation products is sulfonic acid and the formaldehyde is continued not restricted to the particular dye mentioned over too long a period or at too high a term above but may be made to numerous other dyes 65 perature the material enters into a relatively of some of the insoluble stage and is then impracticable for use dyes to w i h p i n f the compounds has in ordinary dyeing operation. een made. The numbers given are those em- An additional test for determination of the Suitability f the product for use in dye levelling the American Association of Textile Chemists 70 operations, involves determination of its power and Coloristto slow up the rate of dye absorption by woolen 252 79 304 goods. This test may conveniently be conducted 179 1054 670 as follows: Prepare a test bath containing 3% 246 53 419 by weight of Sulfone Acid, Blue R designated 114 666 430 75 in the Color Index of 1934, published by the 2.078 833 138 dill ilt

iii)

Sulfonated benzene, toluene, xylene, diphenyl and propylated or butylated benzene, or naphthalene and phenol and alpha or beta naphthol may be substituted for sulfonated naphthalene and condensed with formaldehyde to provide materials which are also contemplated by the present invention. Sulfonation may follow condensation of the aromatic compound with formaldehyde. Other aldehydic agents than formaldehyde, e. g. hexamethylenetetramine acetaldehyde and furfural may be employed.

The levelling agent may be employed in redyeing operations such as speck dyeing in which a readily dyeable material such as wool, that contains some more difiicultly dyeable fibers such as cellulose, is first subjected to the action of an ordinary dye with or without a leveller and is then re-dyed in an additional bath especially suitable .tor coloring the cellulosic fibers. If the latter bath contains the levelling agent disclosed herein, the cellulose fibers will be dyed to approximately the same shade as the wool. If the leveller is omitted, the wool will be much more strongly colored than the cotton.

Although only the preferred forms of the invention have been shown and described, it will be apparent to those skilled in the art that the invention is not limited to these specific forms but numerous modifications may be made therein without departure from the spirit of the invention or the scope of the appended claims.

What I claim is:

i. A dye levelling compound for retarding the fixation of dyes to proteinous materials comprising a reaction product of formaldehyde and naphthalene sulfonic acid, an unneutralized 3.5 gram sample of which, when it is of such water content as to contain .76 gram of naphthalene, will dissolve in 1,500 cc. of water at 90 C. within a period of approximately six to thirty minutes.

2. A method of promoting uniform dye impregnation of woolen textile material with acid dyes comprising incorporating into the bath employed in dyeing the material, a condensation product of naphthalene sulfonic acid and formaldehyde, said condensation product being semi-gelatinous when admixed with 8.4 parts of water per unit weight of naphthalene introduced into the reaction product, and further characterized by the ability to retard the fixation of acid dyes to the textile material.

3. A method of promoting level dyeing of proteinous fibers with acid dyes which comprises introducing into the bath employed in the dyeing operation, a condensation product of naphthalene sulfonic acid and formaldehyde, said condensation product being characterized by the ability to reduce the rate of dye-absorption to approximately 85% or less of the normal rate when introduced into a bath of normally unlevel acid dyestuff and further characterized in that said condensation product is semi-gelatinous when admixed with 8.4 parts of water per unit weight of naphthalene introduced into the reaction product.

4. A method of promoting uniform dye impregnation of woolen textile material with acid dyes, which comprises incorporating into the bath employed in dyeing the material, a condensation product of naphthalene sulfonic acid containing sulfo groups substantially in excess of mono molar ratio with respect to the naphthalene and formaldehyde, the formaldehyde being in a ratio of from .5 to .7, with respect to the naphthalene, said product being semi-gelatinous when admixed with 8.4 parts of water per unit weight of naphthalene introduced into the reaction product, and

further characterized by the ability to retard the fixation of acid dyes to the textile material.

5.. A method of promoting level dyeing of proteinous fibers with acid dyes which comprises introducing into the bath employed in the dyeing operation a reaction product of naphthalenesulfonic acid with from .7 to-l part by weight of 37% formaldehyde, said product. being substantially free of tanning properties, and further characterized by the ability to retard the fixation of acid dyes to the fibers and by the fact that an unneutralized 3.5 gram sample thereof when it is of such water content as to contain .76 gram of naphthalene will dissolve in 1500 cc. of water at 90 C. within a period of approximately 6 to 30 minutes.

6. A method of promoting level dyeing of union fabrics with acid dyes which comprises introducing into the bath employed in the. dyeing operation a reaction product of formaldehyde and naphthalene sulfonic acid, an unneutralized 3.5 gram sample of which, when it is of such water content as to contain .76 gram of naphthalene, will dissolve in 1500 cc. of water at 90 C. within a period of approximately six to thirty minutes.

7. A dye levelling compound comprising a reaction product of naphthalene sulfonic acid with formaldehyde, the formaldehyde being in a ratio of not less than .47 part of 37% concentration with respect to the naphthalene, said condensation product being semi-gelatinous when admixed with 8.4 parts of water per unit weight of naphthalene introduced into the reaction product.

COLVER P. DYE-R.