US 3795480 A
This invention consists of the preparation of durable-press fabrics with basic moieties crosslinked into the fabric. As a consequence of these basic moieties, these fabrics can now absorb acidic optical brighteners. Heretofore, crosslinked cotton fabrics showed poor absorption characteristics for acidic optical brighteners. This fabric basicity is achieved by the use of reactive alcohol additives containing amine groups such as diethanolamine, triethanolamine, monoethanolamine, and 2-dimethylaminoethanol.
Description (OCR text may contain errors)
United States Patent 1191 Harper, Jr. et al.
[ PROCESS FOR PREPARING A DURABLE-PRESS OR WASH-WEAR FABRICS WHICH CAN BE WHITENED WITH ACIDIC OPTICAL BRIGHTENERS  Inventors: Robert J. Harper, Jr.; Gloria A.
Gautreaux, both of Metairie; Eugene J. Blanchard, New Orleans, all of La.
 Assignee: The United States of America as represented by the Secretary of Agriculture, Washington, DC.
22] Filed: Jan. 24, 1972  Appl. No.: 220,415
52 US. Cl 8/18, 8/1 w, 8/17, 8/31, 8/100, 8/185, 8/186, 117/335 T  Field of Search". 8/185,17,18, 31, l W, 186,
 References Cited UNITED STATES PATENTS 2,950,553 8/1960 'l-lurwitz 8/185 [111 3,795,480 14 1 Mar. 5, 1974 3,663,159 5/1972 Gordon 8/185 3,407,026 10/1968 Mauldin 8/185 2,957,746 10/1960 Buck et al 8/185 3,658,457 4/1972 Blanchard et al 8/1 X 3,702,230 11/1972 8/31 X Blanchard et al .7
Primary Examinerl-lerbert B. Guynn Attorney, Agent, or Firm-M. Howard Silverstein [57 ABSTRACT diethanolamine, triethanolamine, monoethanolamine,
7 Claims, N0 Drawings PROCESS FOR PREPARING DURABLE-PRESS R WASH-WEAR FABRICS WHICH CAN BE WHITENEI) WITH ACIDIC OPTICAL BRIGHTENERS A non-exclusive, irrevocable, royalty-free license in the invention herein described, throughout the world for all purposes of the United States Government, with the power to grant sublicenses for such purposes, is hereby granted to the Government of the United States of America.
This invention relates to treatments which impart wrinkle resistance to cellulosic textile materials. In particular,-it relates to a method by which cotton fabrics may be finished so that they will be wrinkle resistant and will have characteristics that will absorb acidic optical brighteners normally used on basic fibers such as ric is then dried and cured in the usual manner. The
crosslinked fabrics arethen laundered to yield a durable-pre s s fabric which contains amine groups crosslinked into the fabric matrix. As a consequence of these basic groups, the fabric now possesses good affinity for acidic optical brighteners.
j Various amounts and types of alcohol amines can be used as reactive additives for the purpose described. In general, the effective range studied has been from about 0.5 percent to about percent of the alcohol amine in the pad bath. The preferred range of operation appears to be from about 1-2 percent. The higher amounts of amine in the formulation sometimes lead to discoloration problems and this is another reason for giving preference to low concentrations in the pad bath. A variety of alcohol amines have been utilized. From the viewpoint of brightener uptake, there are some indications that the amount of brightener absorbed seems to increase with the basicity of the amine fixed on the fabric. In this respect, tertiary amines are better than secondary amines and secondary amines are better than primary amines. Furthermore, from the viewpoint of fabric discoloration, tertiary amines seem to cause less fabric discoloration than secondary amines which in turn seem to cause less discoloration than primary amines. Examples of the tertiary amines used in this work are triethanolamine and 2- 'dimethylaminoethanol. An example of the secondary amine is diethanolamine, and an example of a primary amine is monoethanolamine.
The preferred crosslinking agent with this method 7 appears to be dimethylol dihydroxyethyleneurea. Al-
though other agents are also effective, the preceding agent is particularly effective because it has four N- methylol groups available for crosslinking. As a result, if one methylol moiety is used in reaction with the reactive additive, three other sites are still available for crosslinking cotton. As a consequence, it is possible to obtain fabrics with good durable press ratings and wrinkle recovery values and with a certain amount of amine groups attached to the fabric. Because of these amine groups, the fabric has a-basic character and will now absorb acidic optical brighteners.
Thus, one should consider three cotton fabrics. One fabric is untreated, the other is crosslinked in a conventional manner using crosslinking agent, metal salt catalyst and no reactive amine additive. The third fabric is crosslinked using crosslinking agent, metal salt catalyst, reactive alcohol amine and sufficient acid to neutralize the alcohol amine. Examples of the alcohol amines have been previously mentioned. The fabrics are laundered and are then treated in a bath containing the acidic optical brightener. The fabrics are then rinsed and laundered. The fabrics are inspected under regular and UV light. The sample crosslinked with no amine additive shows poor absorption of optical brightener. The untreated control shows fair to good absorption depending upon the specific optical brightener. On the other hand, the fabrics with the amine additives show excellent absorption of optical brightener. As a consequence, these fabrics appear white under regular light while the crosslinked fabrics without the alcoholic amine additive are somewhat off-colored. Under UV light, the fluorescence due to absorption of brightener can be readily observed. Thus the crosslinked control looks grey while the untreated control may be a fair to some cases, they absorb the acidic optical brightener to a greater extent than the untreated cotton control. This can be observed not only by visual inspection under regular and UV light but also by measurement of the fluorescence of the samples using a spectrofluorometer. Thus, with one acid brightener, the crosslinked samples with triethanolamine additive had from 87-143 percent of the fluoresence of the untreated cotton. By contrast, the crosslinked control with no amine additive had only 7 percent of the absorption of the untreated control. These results readily illustrate the effectiveness of this method in producing a crosslinked fabric which will absorb optical brighteners.
It is believed that this process represents a significant improvement in the state of the art for several reasons. First, it produces a crosslinked cotton fabric with good affinity for acidic optical brighteners. Because normally crosslinked fabrics absorb optical brighteners of any type poorly, they tend to become grey and dingy after a certain amount of use. Because the amine groups are permanently attached to fabrics, the fabrics may be whitened at any time by the application of a bath containing an acidic optical brightener.
A further advantage in this method of whitening fabrics after crosslinking is that while brighteners can. be added in the bath with crosslinking agents, many lose much of their effectiveness under the severe curing conditions (temperature from l50170C) employed in curing resins. As a consequence, better and more efficient use of the'brightener can be obtained if the whitener is applied subsequent to the cross-linking process. Heretofore, this has not been possible. However, in this process, whitener uptake can be achieved both by a bath application equivalent to mild dye conditions or by routine padding and drying conditions of the type frequently used to apply a top softener to fabric.
The major advantage would, however, appear to be in the possibility of whitening fabrics or garments at any time and as frequently during the normal use cycle as the housewife or the laundry so desires. The only agents required are a suitable acid brightener, a source of mild acid (such as household vinegar), and water. The operation can be repeated on the garment whenever the whiteness from the previous application has disappeared due to dissipation of the brightener on fabric caused by removal through repeated laundering, bleaching, heat or light.
The agents needed to modify the fabric in this particular manner are relatively inexpensive, easily added to finishing baths, and can be used in the bath in relatively small quantities.
In general terms, the process of this invention starts with the incorporation of the alcoholic amine in the normal pad bath solution together with sufficient acid to neutralize the basicity introduced by the amine. From this point on, the fabric is finished in a standard manner according to contemporary textile practice. This method can be used with a number of textile formulations, the only requirement being that an appropriate amount of water be replaced by hydroxyamine additive and its neutralizing acid equivalent. The method is readily applicable to either precure or postcure one-bath one-step treatments. Moreover, for demonstration purposes, it has been applied to other finishing methods such as the moist cure or easy cure methods. The fabrics are then laundered. At this point, the whitener can then be applied using mild dye bath conditions or by repadding and drying the fabric. Gar ments can be treated at any time during their use cycle by the housewife, laundry or garment maker. Furthermore, the operation can be repeated whenever it would appear to be advantageous during the life cycle of the garment.
A number of hydroxyamines have been employed as reactive additives. Typical of such agents are triethanolamine (A) diethanolamine (B) monoethanolamine (C),
and Z-dimethylaminoethanol (D) Other agents can easily be visualized. The only requirements would be that the compound carry a hydroxyl group for reaction with the crosslinking agent and a basic amine moiety for imparting a basic character to the fabric.
Although the description to this point concerns the use of all-cotton fabrics, applications could be made to blended fabrics as well. Blends of wool-cotton, wool, nylon and cotton or cotton-nylon might be especially susceptible to improvement since the acid brighteners would be expected to be helped by these treatments. This is because the basicity imparted to the cotton component together with the natural basicity of these fibers should make these fabrics have good absorption characteristics for the acidic brighteners since all components would be activated. This method has also been applied to polyester-cotton fabrics. In this case, only the cotton component :is activated by erosslinking in the reactive amine alcohol. However,-the overall fabric is considerably whiter due to the absorption of the acidic optical brightener when compared with the polyester-cotton fabric with a conventional crosslinking treatment.
To summarize, this invention can best be viewed as a .process for imparting receptivity of acid optical brighteners to crosslinked cotton fabrics. Normally crosslinked cotton fabrics have poor receptivity for acidic optical brighteners. The improvement consists in the use of hydroxy amines as coreactants In normal crosslinking systems. As a consequence, crosslinked fabrics are obtained containing pendant amine groups fixed on the fabrics. Whitening procedures can now be applied to these-fabrics using acidic optical brighteners,
which would be substantive to a basic substrate. Cotton crosslinked in the normal manner and occasionally untreated cotton fabrics have poor substantivityor affinity for acidic optical brighteners.
Only the basic formulations have been used in these examples. Variations using softeners, wetting agents, polymer additives and various finishing systems are readily accessible for anyone skilled in the art of textile finishing.
EXAMPLE 1 One set of cotton printcloth was padded with a solution containing 9 parts dimethylol dihydroxye thyleneurea, 0.5 parts zinc nitrate hexahydrate and 90.5 parts water. The fabric was dried for 7 minutes at 60C and cured for 5 minutes at C. The fabric was then laundered and tumble dried.
A second set of cotton printcloth was finished with modified formulations and cured in the same manner. The modifications consisted of replacing equivalent number of parts of water with the same number of parts of base and neutralizing with acid to maintain pH at leass than 5 The bases used were triethanolamine (0.5, l, 2, 3, 5 parts in the padding solution); diethanolamine l 2, 3, 5 parts in the padding solution), monoethanolamine (I, 2, 3, 5 parts in the padding solution), and 2- dimethylaminoethanol (0.5, l, and 3 parts in the padding solution). After the various samples treated with the modified formulation were prepared and laundered, they represented a series of fabrics in which the fabrics had good wash-wear or durable-press appearance, wrinkle recovery values ranging from 250 to 280 and grafts on the fabric containing these attached amine groups. The presence of these amine grafts was indicated by the fact that these reactive additives led to an increase both in total fabric add-on as well as in bound nitrogen on the fabric.
Small swatches of two sets treated above together with an untreated cotton control were then immersed in a bath prepared from 0.5 percent Fluorescent Brightener 134 [Color Index Name: 1968 Edition w American Association of Textile Chemists and Coloriss Section D, pp 1-128] and 99.5 parts water heated to 3035C. The samples were agitated in this bath at this temperature for 30 minutes and then the temperature was increased to 4045C for an addi' tional period of 30 minutes. The samples were then rinsed seven times with distilled water and heated to 35C for 5 minutes. One swatch of each sample was then laundered on the wash-wear cycle using warm water.
The samples were then inspected under regular light, UV light, and by use of the Farrand Spectrofluorometer. Very little difference could be detected between the series of samples given a regular wash and the remaining series of samples washed only in distilled water.
Under regular light, the samples which appeared whiter than the crosslinked control were those samples in which triethanolamine or 2dimethylaminoethanol were used as reactive additives. At low level concentrations with diethanolamine, improvement in whiteness relative to the crosslinked control was noted, but at high level concentrations, there is a distinct lack of improvement due to discoloration on curing arising from the amine. With monoethanolamine a distinct discoloration arises right from the start so a practical application using this reagent would seem to depend upon the elimination of color during curing. The fact that the fabrics with the amine additives were whiter than the crosslinked controls reflects the effectiveness of the overall process of using an acidic optical brightener on a basic fabric.
These results were further demonstrated by the inspection of these fabrics under UV light. Under UV light, the cross-linked control is grey, the untreated control fluoresces a bright white and all the samples with the amine crosslinked into the fabric fluoresce and appear to be white similar to the untreated control fabric. This is another distinct indication that by the use of an acidic optical brightener (such as would normally be used on a basic fabric, such as wool), one obtains good absorption of the brightener even though the fabric is crosslinked. This absorption is achieved because the fabric has had basic groups crosslinked into the fabric structure.
As a further demonstration of the effectiveness of this approach, the samples were measured for fluorescence using a Farrand Spectrofluorometer. The fluorescence was measured at 445 mp, which was the peak amines showed absorption ranging from 82-94 percent of the untreated control. The fabrics treated with DMDHEU and secondary amines showed absorption from 6077 percent of the untreated control. The fabrics treated with DMDHEU and primary amines showed absorption from 3445 percent of the untreated control. Under the circumstances, the cross linked control with no amine additive showed absorption from only 10-12 percent of the untreated control. These results clearly indicate the effectiveness of the amine additives in producing fabrics with good absorption characteristics for acidic optical brighteners. Furthermore, Table l readily shows that the amine additives are very effective at relativelylow levels of amine inthe pad bath solutions. With only 1% triethanolamine in the pad bath solution, fluorescent absorption was 83 percent of the untreated control.
This experiment readily demonstrates the effectiveness of this approach in improving the whiteness and absorption of fluorescent brighteners by crosslinked fabrics.
TABLE 1 FLUORESCENCE OF CROSSLlNKED FABRICS TREATED WITH FLUORESCENT BRIGHTENER 134 The fluorescence of the untreated cotton fabric was taken to be and everything else is reported relative te this.
EXAMPLE 2 Swatches of the samples prepared in Example 1 were treated with a bath containing an acidic optical brightener of the Stilbene type. The bath contained 0.5 parts of the acid brightener and 99.5 parts water. The pH was adjusted from 7 to 4.5 using dilute HCl. The fabrics were immersed in the bath at 35-38C for a period of 30 minutes; the temperature was raised to 52C for a period of 30 minutes and then allowed to cool to 40C over a period of 30 minutes. The fabrics were then washed in distilled water seven times and then heated to 40 in distilled water, rinsed and tumble dried. With respect to the whiteness of the final fabrics, those treated with tertiary amines (that is, triethanolamine and 2- dimethylaminoethanol) and crosslinking agent were distinctly whiter than the crosslinked control and somewhat whiter than the untreated cotton. The samples treated with DMDHEU and diethanolamine were whiter than the crosslinked control particularly in the case in which a lower level of amine was used in the pad bath. With the higher levels of secondary amines and the samples treated with primary amines, the discoloration arising on curing tended to overcome the effect of the absorption of brightener.
Likewise, inspection of these samples under UV light showed the distinct effects of the grafted amine additives on the absorption of the acidic optical brighteners. Thus, the crosslinked control appeared to be grey, and the untreated cotton showed fair absorption of brightener and fluoresced. On the other hand, the samples with amines crosslinked in the fabric showed strong absorption of optical brightener and strong fluorescence under UV light.
This strong absorption of brightener likewise clearly demonstrates the effectiveness of this procedure in producing a crosslinked fabric which shows good absorption of an acid optical brightener. The contrast with the crosslinked control is marked. A further example of the effectiveness of this procedure can be found by measuring the fluorescence of the samples using a Farrand Spectrofluorometer. As the results in Table II indicate, the fluorescence of the samples with tertiary amines crosslinked into the fabric ranged from 87-143 percent of the untreated cotton. With the secondary amines crosslinked into the fabric, the fluorescent values were 65-83 percent of the untreated control. Similarly, with the samples with primary amines crosslinked into the fabrics, fluorescent values were 41-54 percent of the untreated cotton. By contrast, the crosslinked control with no amine additive had only 4-7 percent of the absorption of brightener as the untreated cotton control. Furthermore, as the figures in Table II show, excellent absorption of optical brightener was achieved using a were padded with a solution prepared from 0.75 parts Fluorescent Brightener I25, 1 part glacial acetic acid; and 98.25 parts water. After this the fabrics were rinsed thoroughly in distilled water (8 washings) and dried, and they were inspected under regular and UV light. While the crosslinked sample with no additive was discolored, the samples with the triethanolamine, diethanolamine, and 2-dimethylaminoethanol were whiter both with respect to the crosslinked control and the un- 0 treated cotton fabric. Furthermore, a parallel effect which 'a high level of triethanolamine was crosslinked into the fabric was taken to be 100 percent On this basis, as indicated in Table III, the crosslinked control showed only 10 percent of the fluorescent value as the control while the untreated cotton showed 24 percentv 25 of the fluorescent value of the control. On the other 58-78 percent and those with primary amines crossrelatively low level of additive agent in the padding solution.
TABLE II hand, while the samples with tertiary amines crosslinked into the fabric showed fluorescent values ranging up to 76-100 percent, the fabrics with secondary amines crosslinked into the fabric showed values from linked in the fabric had values from 28-46 percent of the control. I
The results clearly show that fabrics treated by this process can be selectively whitened with an acidic brightener using an afterwash type of padding conditioner. The fabrics treated with crosslinking agent and amine additives absorb the brightener to a much ABSORPTION OF STlLBENE TYPE ACID BRIOHTENER BY BASIC FABRICS 7r Amine All samples were given a conventional pad-dry-cure treatment as described in xams 2 Fluorescenee ef ilntreated eo tto n was taken as with everything else reportedrelative to this. Fluorescence was measured at 450 mp.
EXAMPLE 3 Swatches of samples of the fabrics from Example 1 greater extent than the crosslinked control or, for that matter, the untreated cotton fabric.
TABLE III FLUORESCENT MEASUREMENTS OF ALL COTTON FABRICS TREATED WlTH FLUORESCENT BRlGHTENER 125 Y "ln this case, the fluorescent value of the sample cross-linked in the presence of 5% triethanolamine was taken as 100%. Fluorescence was measured at 445 mu.
EXAMPLE 4 A sample of 50-50 polyester-cotton (a blend containing 50 percent cotton and 50 percent polyester) was treated with 9 parts dimethylol dihydroxyethyleneurea, 0.5 parts zinc nitrate hexahydrate, and 90.5 parts water. The fabric was dried for 7 minutes at cent Brightener 134). The procedure used in Example 1 was employed in this case. An observable improvement was noted in the whiteness of the fabrics under either regular or UV light for the samples with the tertiary amines (triethanolamine and 2- dimethylaminoethanol) crosslinked into the fabric. The improvement is not as great as with all cotton fabrics TABLE W '50-50 POLYESTER-COTTON FABRIC, Treated with Fluorescent Brightener 134 7r 7! Amine in Type of Amine DMDHEU Pad Bath in Pad Bath Fluorescence 9 0 0 29 9 0.5 Triethanolamine 9 1.0 Triethanolamine 56 9 3.0 Triethanolamine 73 9 0.5 Z-Dimethylaminoethanol 9 1.0 2-Dimethylaminoethanol 76 9 3.0 Z-Dimethylaminoethanol 76 Untreated polyester-cotton 76 100 Untreated cotton C and cured for 5 minutes at 160C. The fabric was then laundered and tumble-dried. Other samples of the same fabric were finished with modified formulations and cured in the same manner. The modification consisted of replacing an equivalent number of parts of 55 water with the same number of parts of base and sufficient neutralizing acid to maintain the pH of the treating baths at less than 5. The bases used were triethanolamine (0.5, 1, and 3 parts in the padding solution) and 2-dimethylaminoethanol (0.5, 1, and 3 parts in the padding solution). After these samples were prepared and laundered, they represented a series of fabrics. in which the fabrics had good wash-wear or durable-press appearance, high wrinkle recovery values and grafts on the fabrics containing the previously mentioned amine groups. Samples of these fabrics were then treated with a bath containing an acidic optical brightener (Fluoresbut as shown in Table 1V, the amount as measured by the Farrand Spectrofluorometer is substantial. Indeed at the high level of amine treatment, the'value of the fluorescence of these fabrics was close to that of the untreated polyester-cotton. It might be noted that the polyester fiber is made with an optical brightener in it which is a factor which tends to average out the results with blended fabrics.
Samples of the above fabrics were also padded with Fluorescent Brightener using the procedure reported in Example 3. The samples were then checked using the Farrand Spectrofluorometer and the results are reported in Table V. it can be readily observed in Table V that the fluorescent values of the crosslinked samples with amine additives are substantially higher than for the control samples with'no amine additive in the finishing formulation. 7
' TABLE v 50-50 POLYESTERCOTTON FABRICS TREATED WITH FLUORESCENT BRIGHTENER 125 The fluorescence value of a cotton sample crosslinked with triethanolamine in the pad bath was taken as 100%.
EXAMPLE 5 A cotton fabric was padded with a moist cure formu lation and the moisture content was reduced to 7% using air drying conditions. The fabric was sealed in a plastic bag and allowed to remain in the bag for 24 hours at room temperature. The fabric was then laundered. The moist cure formulation was prepared using 13.5% dimethylol dihydroxyethyleneurea, sufficient hydrochloric acid to lower the pH to 1, and the remain- 25 Samples of these fabrics were then treated with a bath containing an acidic optical brightener (Fluorescent Brightener 134). The procedure employed in Example was used in this case. Not only were the samples with the amine additive whiter under regular light but also they were distinctly whiter than the. moist cure crosslinked control under UV light. Furthermore, when the samples were measured using the Farrand Spectro- TABLE vi fluororn eter, the results reported in Table VI were ob tained. In this case, it is readily noticed that the samples treated with the amine additives showed significantly better absorption of the acidic optical brightener than the control sample treated with erosslinking agent and no reactive amine additive. The effectiveness of this process indicates that the use of a reactive amine additive in finishing can be applied not only with standard pad-dry-cure treatments but also can be used in other finishing systems.
Samples of the moist cure fabrics were also padded with Fluorescent Brightener 125 using the procedure employed in Example 3. Not only were the samples treated with cross-linking agent and amine additive whitener under regular and UV light but Fluorescent values were significantly higher than the crosslinkcd control when measured using a Farrand Spectrofluorometer as listed in Table VII. Thus, while the moist cure control showed 6 percent of the fluorescence of the standard, the moist cure samples with reactive amine additives had values ranging from -78 percent of the standard (in this case, pad-dry-cure sample with 9% DMDHEU and 5% triethanolamine in the pad bath. These results clearly demonstrate that the overall process can be employed in a variety of finishing systems provided the basic concept is maintained throughout.
MOIST-CURE TREATED COTTON FABRICS TREATED WITH FLUORESCENT BRIGHTENER 134 Untreated cotton control TABLE VII MOIST-CURE TREATED COTTON FABRICS PADDED WITH FLUORESCENT BRIGHTENER 7r Amine in Type of Amine in 72 DMDHEUI Pad Bath Pad Bath Fluorescence 13.5, 0 None 5 13.5 1 Triethanolarnine 13.5 1 Z-Dimethylaminoethanol 5 2 13.5 3 Triethanolamine 66 MOlST-CURE TREATED CQTTON FAERICSJBEATEP WITH FLUORESCENT BRlGl-ITENER 125 Untreated control The pad-dry-cure sainple with 9% DMDHEU and 5% triethanolamine additive was the standard given 100% value in this case. Other members of the series are expw dmjm euta ebasis- Samples were given 'standard moist cure treat ment using 061111765113; 'ir'aea'd'r'es;
and agentsas described in the beginning of Example 5.
EXAMPLE 6 Cotton fabrics were given an easy cure finish by padding the fabrics in a finishing bath, and then heating in a forced draft oven at 60C. One fabric was heated for seven minutes and the other for nine minutes. The
finishing bath was prepared by using 13.5 parts dimethylol dihydroxyethyleneurea, 1 part hydrochloric acid and 85.5 parts water. Two other sets of fabrics were run in which 3% triethanolamine and 3% 2- dimethylaminoethanol were added to the finishing formulation together with sufficient acid to reduce the pH to the same level as the control treatment without additive. After these samples were washed, they yielded two series (7 and 9 minute cures) of easy cure fabrics with amine grafts and appropriate controls. Samples of these fabrics were then treated with an acidic optical brightener (Fluorescent Brightener 134). The procedure employed in Example 1 was used in this case. Not only were the samples with the amine additive whiter under regular light but also they were whiter than the easy cure control under UV light. Furthermore, when the samples were measured with a Farrand Spectrofluorometer using the conditions and the same standard samples as in Table V1, then the sample with the 7 minute easy cure treatment and no amine additive had 1 1 percent of the fluorescence of the untreated cotton control. With 3% triethanolamine as an additive, the fluorescence was 74 percent of the untreated control whereas with 3% dimethylaminoethanol as an additive the value was 68 percent of the untreated cotton control. For the samples given a 9 ininute cure, the fluorescence values were 14 percent for the easy cure sample with no additive, 60 percent for the easy cure sample with 3 percent triethanolamine additive, and 69 percent for the easy cure sample with the 2- dimethylaminoethanol additive. Thus, it is readily noticed that samples with the reactive amine additives showed significantly better absorption of the acidic optical brightener than the control samples treated with crosslinking agent and no amine additives. These results again serve to demonstrate the versatility of the process with other than the standard pad-dry-cure treatment.
Samples of the easy cure fabrics were also padded with Fluorescent Brightener 125 using the procedure employed in Example 3. Not only were the samples treated with crosslinking agent and amine additive whiter under regular and UV light but fluorescent values were significantly higher than the easy cure control when measured using a Farrand Spectrofluorometer. Thus, with the series cured 7 minutes and (with the conditions and standard sample from Table VII), the
easy cure control with no amine additive had 6 percent of the fluorescent value of the standard. On the other hand, the easy cure sample with 3% triethanolamine had 100 percent of the fluorescence as the standard while the easy cure sample with 3% 2- dimethylaminoethanol had 84 percent of the fluorescence of the control. These results clearly demonstrate the favorable effect of the use of the amine additive in producing a crosslinked fabric, which will absorb acidic optical brighteners from a pad bath. This represents another example of the effectiveness of the overall process, irrespective of the particular finishing system utilized.
1. A process for imparting durable press performance and an affinity for an optical brightener to a cellulosic fabric subsequent to crosslinking thereof, comprising:
a. impregnating a cellulosic fabric with an aqueous solution containing from about 1 -to 15 weight percent of dimethylol dihydroxyethyleneurea as a crosslinking agent for cellulose, about from. 0.5 to 4.0 weight percent of an acidic reagent for catalyzing the crosslinking reaction between the fabric cellulose and said crosslinking agent, about from 0.2 to 5.0 weight percent of an alcoholic amine selected from the group consisting of monoethanolamine, diethanolamine, triethanolamine, and 2- dimethylethanolamine, and sufficient acid to neutralize the vasicity of said amine;
b. drying the impregnated fabric from step (a) at a temperature of about from 25 C. to C. for a period of about from 2 minutes to 24 hours;
0. curing the dry fabric from step (b) at a temperature of about from C. to C. for a period of about from 30 seconds to 20 minutes to effect crosslinking of the fabric; and
d. treating the crosslinked fabric from step (c) with an acidic optical brightener.
2. The process of claim 1 wherein the alcoholic amine is monoethanolamine.
3. The process of claim I wherein the alcoholic amine is diethanolamine.
4. The process of claim 1 wherein the alcoholic amine is triethanolamine.
5. The process of claim 1 wherein the alcoholic amine is 2-dimethylethanolamine.
6. The process of claim 1 wherein the acidic catalist is zinc nitrate hexahydrate. V
7. The process of claim 1 wherein the acidic optical brightener is of the Stilbene type.