US3536735A - Oleophilic anthraquinone red dyes for polypropylene - Google Patents

Description

United States Patent 3,536,735 OLEOPHILIC ANTHRAQUINONE RED DYES FOR POLYPROPYLENE Stanley B. Speck, Wilmington, Del., assignor to E. I. du Pont de Nemours and Company, Wilmington, Del., a corporation of Delaware No Drawing. Filed June 27, 1967, Ser. No. 649,128 Int. Cl. C07c 97/14; C09b 1/54 US. Cl. 260-380 3 Claims ABSTRACT OF THE DISCLOSURE The composition of matter having the structure:

wherein R and R are selected from the group consisting of sec-butyl, sec-amyl and tert-amyl.

BACKGROUND OF THE INVENTION This invention relates to a polypropylene dye for use in a process for dyeing a fabric comprising polypropylene backing and non-olefinic tufting fibers in an aqueous dyebath in combination with dyes normally used with the tufting fibers.

For many uses it is important that the backing of a tufted fabric be dyed a color approximating that of the tufting yarn. This is especially true with tufted carpets in which the tuft frequency is low, since an undesirable show through of the contrasting backing can occur, especially if the carpet is bent as around a stairstep.

Most carpet backings are woven jute fabrics which are light brown in color. They present the problem of backing show through only when tufting yarns having a color contrasting that of the backing are used. When dyeing of the jute backing is required, it is necessary to carry out the dyeing of the tufting yarn in one step, after which the dyebath must be drained, the tufted fabric rinsed and in a separate step a new dyebath for the backing added.

Spun-bonded polypropylene sheet material is now available to replace jute as primary carpet backing; that is, as the material through which the nylon, arcylic, or wool face yarn is tufted. The problem of show through is aggravated because of the relative low dyeability of polypropylene.

The spun-bonded polypropylene of concern to this invention is the commercial, unmodified polypropylene Ice homopolymer, rather than a disperse dyeable modified type.

Dyeing of polypropylene fibers containing no additives for improving dyeability requires relatively nonpolar dyes which usually have poor fastness properties. As noted in The Dyeing of Polypropylene for Texiles, American Dyestuif Reporter, p. 35, Feb. 15, 1965, no existing class or classes of dyestuffs could provide an adequate range of shades with acceptable fastness properties, most polypropylene dyes are inadequate in fastness. If a tufting yarn other than polypropylene is used, for example, nylon, dyeing with polypropylene dyes alone gives undesirable shades on the tufting fibers. Use of a more polar dye suitable for dyeing the pile yarn results in little or no coloration of the polypropylene backing.

It has now been found that combinations of the backing dyes of the invention, with conventional pile yarn dyes, can be applied from a single aqueous dyebath sysf tem to a tufted fabric having a polypropylene backing and non-olefinic pile yarns with substantial elimination of backing show through and other unexpected advantages. It appears that these backing dyes show greater afiinity for the polypropylene backing than the tufting yarn, have good leveling properties, dye at approximately the same rate as the tufting yarn dyes, cause no off-shade staining of the tufting yarns, are compatible with most dyeing systems and do not adversely atfect the fastness of the dyed tufting yarn.

SUMMARY OF THE INVENTION Oleophilic anthraquinone red dyes for polypropylene having the structure:

where R and R' are selected from the group consisting of sec-butyl, sec-amyl and tert-amyl.

DESCRIPTION OF THE INVENTION The dyes of this invention have the structure:

where R and R may be GHCH2CH3 -GHCH GHzCH omen These dyes may be prepared by reacting 1-amino-2- bronio-4-hydroxyanthraquinone with the appropriate 2,4- dialkylphenol, for example 2,4-di-sec-amylphenol. This reaction is carried out by reacting the above two components and potassium carbonate in a solvent such as dimethylformamide. Upon heating to approximately 130 C. for approximately 7 hours, the substitution is complete. With a twofold excess of the alkylphenol, a yield of about 85% is obtained.

The crude dye is isolated by first cooling the reaction mixture to about 65 C., then adding twice as much methanol as the solvent dimethylformamide. The slurry is then further cooled to 30 C., another volume of methanol equal to the original volume of dimethylformamide is added, and the slurry is cooled by an ice bath for approximately two hours. The crude dye is then isolated by filtration, washed with methanol and hot water, and dried.

The dyes of this invention may be used for the union dyeing in an aqueous dyebath of a pile fabric having a polypropylene backing and a polyamide pile. This result is obtained by using a combination of a polypropylene dye of this invention and other dyes which dye the nylon fiber, such dyes dyeing at approximately the same rate and not interferring one with the other with respect to transfer, shade, or fastness on the respective fibers.

Preferably, the dyebath also contains a dispersing agent taken from the group consisting of a condensation product obtained by reacting a major portion of ethylene oxide with a minor portion of fatty alcohol, a low molecular weight poly(ethylene oxide) coupled with an anionic surface active agent, a sodium hydrocarbon sulfonate, sodium C -{Z fatting alcohol sulfate and the disodium salt of dodecylated oxydibenzenesulfonic acid, a pH controlling agent taken from the group consisting of acetic acid, hydrochloric acid, sulfuric acid, acetic acidsodiuni acetate and sodium phosphate buffers, and optionally a dyeing assistant taken from the group consist ing of the sodium salts of ethylenediaminetetraacetic acid, poly(dimethylsiloxane), sodium chloride, sodium sulfate and ammonium sulfate. It is further preferred that the aqueous dyebath is approximately -100 times the weight of the tufted fabric being dyed and that the maximum temperature of the dyebath is between 200 F. and the boiling point of the dyebath.

The process of using the dyes of this invention is disclosed in copending application, S.N. 585,781 filed Oct. 11, 1966.

Dyes which may be used in combination with the dyes of this invention in the method outlined above are dispersed dyes such as C.I. Disperse Red 55, Cl. Disperse Red 17, or acid dyes such as C.I. Acid Red 266 and Cl. Acid Red 151.

The polypropylene used in the backing usually will contain minor amounts of various stabilizers to guard against oxidative, thermal and ultraviolet light degradation and may also contain additives to improve dyeability as long as these dyeability improving additives do not cause shade changes in the polypropylene dyes or interfere with the shade or application of the nylon dyes.

4 The following examples are illustrative of this invention.

EXAMPLE 1 A charge of 500 cc. dimethylformamide, 351 g. of 2,4- di-sec-amylphenol, 170 g. potassium carbonate and 318 g. l-amino-2-bromo-4-hydroxyanthraquinone was heated at C. with good agitation. The reaction was complete in seven hours as determined by thin layer chromatography. The reaction mixture was cooled to 65 C. and 1000 cc. of methanol were added. The mixture was then cooled to 30 C. and an additional 500 cc. of methanol were added. The mixture was cooled in an ice bath for two hours, then the dye was collected on a filter, washed twice with methanol and then thoroughly with hot water. A yield of 293 g. or 62% of crude dye was obtained. They dye melted at 131-133 C. and had an absorptivity of 31.35 at 515A.

EXAMPLE 2 Substitution of 420 g. 2,4-di-sec-butylphenol for the 2,4-di-sec-amylphenol used in Example 1 gave the subject red dye with M.P. 147-150 C. and an absorptivity of 32.0 at 515x.

EXAMPLE 3 Substitution of 700 g. of 2,4-di-tert-amylphenol for the 2,4-di-sec-amylphenol used in Example 1 gave the subject red dye with M.P. C. and an absorptivity of 3.15 at 515%.

EXAMPLE 4 Candidate dyes were dyed, self-shade, on carpet made of nylon tufted to polypropylene by a conventional dyeing procedure for dyeing nylon carpet with disperse dyes:

The carpeting may be made by tufting nylon yarn onto an unmodified polypropylene backing. The nylon yarn used in this example is 3700 denier, 204 continuous filaments, trilobal, jet-bulked yarn, melt spun from poly- (hexamethylene adipamide) flake. The yarn is jet-bulked with the jet taught in U. S. Pat. 3,005,251.

The bath is set at room temperature with:

1.0% of a nonionic surfactant (e.g. the condensation product of 55 moles of ethylene oxide with one mole of C amine),

0.5% of an anionic surfactant sodium salt of the sulfonation product of mixed long-chain hydrocarbons, and

1% trisodium phosphate to give a pH of 9.

The dyes are added as a milled paste or as crude dye dissolved in dimethylformamide. The carpet is added to the bath, the temperature raised to boiling and maintained at that temperature for one hour. The dyebath is then dropped and the carpet rinsed with warm water.

Reflectance spectra were taken with a GE. Spectrophotometer of (a) the nylon tuft surface, and (b) polypropylene backing from which the nylon had been removed. The polypropylene sample was always mounted in two thicknesses, so that the tufting holes were backed up by the second layer of polypropylene.

A standard table (prepared by Davidson and Hemmendinger, Easton, Pa., based on the Kubelka-Munk equation) was used to convert percent reflectance at A to a value termed K/S. K/S is approximately linear with dye concentration; for these studies it was adequate to assume K/S was an accurate measure of the dye concentration on either material.

The ratio of K/S for polypropylene to K/S for nylon has been used as the relative percent on polypropylene backing. This ratio has also been referred to as the partition coefficient, as prime measure of the usefulness of a polypropylene dye in terms of minimal 'staining of nylon.

The above method was used to obtain the data presented in Table I.

TABLE I.DYEING PROPERTIES N POLYPROPYLENE IN PRESENCE OF NYLON Dyes evaluated Partition No. R coefficient Build-up Exhaust 0 IYIH; 1.... -C H 0 None (No dye on polypropylene) CH OR 2 (|JCH; Very poor (polypropylene only slightly stained) Very poor.

II I GHQ-CH3 O OH I 3.-.- CCH Very poor (0.2% dyeing no deeper than 0.04%) Do.

l I 1 4 @-(|J--(3H 130 --do Do.

CH CH (I'JHCHaC a 5 @(I3HCH 480 Good 0.2% dyeing 350% deeper than 0.04%) Fair.

E CH3 CHa-(FH-CHgCHzCH 6 -@(IJHCH; 480 Good (0.2% dyeing 345% deeper than 0.04%) Do;

The results presented in Table I show that dyes 1-4 exhibit very poor dyeing afiinity for the polypropylene carpet backing, and rather severe nylon stain. Dyes 5' and 6, on the other hand, exhibit surprisingly good aflinity for the polypropylene backing with only a minimum of nylon stain. In addition, dyes 1-4 show very poor build-up of shade. Dyes 5 and 6, on the other hand, exhibit surprisingly good build-up on the polypropylene backing.

EXAMPLE 5 Thirty parts of the carpeting described in Example 4 were installed in dyebath equipment. First, the carpet was scoured at 180 F. (82 C.) for 20-30 minutes in a hath made up of 1000 parts water, 0.2 parts of a nonionic surfactant (the condensation product of 20 moles of ethylene oxide with one mole of oleyl alcohol), 0.6 part conc. ammonium hydroxide and 0.15 part sodium hydroxide. The bath is then dropped and the carpet is rinsed with clean water. A dyebath is then made up of 1000 parts water, 0.45 part of dodecyldiphenyl ether disulfonic acid, disodium salt (U.'S. 2,081,876), 0.15 part of the nonionic surfactant described above and 0.15 part of tetrasodium ethylenediaminetetraacetate. The pH is adjusted to 9.0 with tetrasodium pyrophosphate and 0.075 part of the red acid dye (Color Index Acid Red 266) and 0.03 part of the oleophilic dye of Example 1 are added. The pH is adjusted to 6.0 with acetic acid. The bath temperature is raised to 200 F. (99 C.) over 45 minutes and the dyeing is continued for one hour. The bath is dropped and the carpet is given a warm water rinse.

Both the nylon and backing are dyed red and to comparable depths.

EXAMPLE 6 A dyebath, for parts of carpeting, is made up of 1000 parts of water, 0.3 part of a nonionic surfactant (the condensation product of 55 moles of ethylene oxide with one mole of C amine), 0.15 part of an anionic surfactant (sodium salt of the sulfonation product of mixed long-chain hydrocarbons), 0.15 part of tetrasodium ethylenediaminetetraacetate, and the pH adjusted to 8.5 with trisodium phosphate. The temperature is raised to F. and 0.075 part of a red disperse dye similar to Color Index Disperse Red 55 and 0.03 part of the oleophilic dye of Example 1 are added. The bath temperature is raised to 208 F. over 45 minutes and the dyeing is continued for one hour. The bath is cooled to 180 F. and then drained. The carpet is given a warm water rinse.

Both the nylon and polypropylene backing are dyed red and to comparable depth.

EXAMPLE 7 A commercial dyebath employing both polypropylene and acid dyes was prepared as follows: An aqueous bath was set at 80 F. with 0.3% antifoam agent, 2.0% dyeing assistant, dodecyldiphenylether disulfonic acid, disodium salt (US. 2,081,876), 0.5% surface active agent, the condensation product of 20 moles of ethylene oxide with one mole of C alcohol, 1.0% trisodium phosphate and 1.0% metal sequestering agent, ethylenediamine tetraacetic acid tetrasodium salt. The pH of the bath was adjusted to 8.5 to 9.5 with trisodium phosphate. The carpet to be dyed was run in the bath for 10 minutes after which 1.0% monosodium phosphate and enough acetic acid to adjust the pH to 6.0 to 6.5 were added. The carpet was run in the bath another 10 minutes and then the acid dye for the nylon and the polypropylene dye were added. The amount of dye added depended on the depth of shade desired in the final carpet color. The carpet was run in the dyebath for 10 minutes and then the temperature of the bath raised to 206 to 208 F. at 3 per minute. The dyebath was run at the higher temperature for one hour and then the bath dropped, and the dyed carpet rinsed.

EXAMPLE 8 A commercial dyebath employing both disperse and polypropylene dyes was prepared as follows: An aqueous bath was set at 80 F. with 0.3% antifoam agent, 1.0% surface active agent, the condensation product of 55 moles of ethylene oxide with one mole of C amine, 0.5% sodium salt of the sulfonation product of mixed long-chain hydrocarbons, 1.0% ethylenediamine tetraacetic acid tetrasodium salt, and 1% tetrasodium pyrophosphate. The pH of the bath was adjusted to 8.5 to

9.5 with trisodium phosphate. The carpet to be dyed was run in the bath for 10 minutes after which the disperse dye for the nylon and the polypropylene dye were added. The amount of dye added depended on the depth of shade desired in the final carpet color. The carpet was run in the dyebath for 10 minutes and then the temperature of the bath raised to 205 to 208 F. at 3 per minute. The dyebath was run at the higher temperature for one hour and then the bath dropped and the carpet rinsed.

In Examples 5, 6, 7, and 8, the excellent lightfastness, transfer, level dyeing, streak coverage, chemical fastness, etc., of the nylon dyes was unaffected by the presence of the polypropylene dye. In addition, neither of the nylon dyes impart any stain to the polypropylene backing; the polypropylene backing is completely resistant to normal nylon dyes. Thus, both nylon face yarn and polypropylene backing can be dyed simultaneously. This simultaneous dyeability is an advance in the art, providing an economic advantage, since dyeing of jute backing must be done in a separate step; simultaneous dyeing saves the expense of the extra dye cycle.

It is to be understood that the preceding examples are representative and that said examples may be varied within the scope of the total specification, as understood by one skilled in the art, to produce essentially the same results.

As many widely ditferent embodiments of this invention may be made without departing from the spirit and scope thereof, it is to be understood that this invention is not limited to the specific embodiments thereof, except as defined in the appended claims.

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. A composition of matter of the structure:

3,226,177 12/1965 Hosoda et al 260380 LORRAINE A. WEINBERGER, Primary Examiner R. GERSTL, Assistant Examiner U.S. Cl. X.R.